AP2972,2A,16V同步降压转换器

Roland van RoyAN032 – Jan 20151. 简介 (2)2. 电流模式降压转换器 (2)3. 立锜之电流模式- COT（CMCOT）降压转换器 (4)4. 立锜之ADVANCED-COT (ACOT TM) 降压转换器 (5)5. 测量结果比较 (7)6. 总结 (10)降压转换器架构之比较1. 简介降压转换器被广泛应用于各种消费性和工业上的应用之中，其中常需转换器将较高的输入电压转换成一较低的输出电压。

现有的降压转换器效率非常好，并能在变化范围很大的输入电压和输出负载的条件下，仍产生调节良好的输出电压。

降压转换器有很多不同的回路控制方式：在过去，被广泛使用的是电压模式和电流模式，然而近来恒定导通时间（COT）架构也常被使用，而有些降压转换器则是同时由电流模式和恒定导通时间来控制的。

立锜的DC-DC 产品组合包含了多种降压转换器，包括电流模式（CM），电流模式-恒定导通时间（CMCOT）和先进恒定导通时间（ACOT™）等架构。

每种架构都有其优点和缺点，因此在实际应用中要选择降压转换器时，最好能先了解每种架构的特点。

2. 电流模式降压转换器电流模式降压转换器之内部功能框图显示于图一。

图一、电流模式转换器之内部功能框图在典型的电流模式控制中，会有一个恒定频率来启动高侧MOSFET，并有一误差放大器将反饋信号与参考电压作比较。

然后，电感电流的上升斜率再与误差放大器的输出作比较；当电感电流超过误差放大器的输出电压时，高侧MOSFET 即被关断(OFF)，而电感电流则流经低侧MOSFET，直等到下一个时钟来到。

电流斜坡再加上斜率补偿之斜坡是为要避免在高占空比时的次谐波振荡，并提高抗噪声性能。

电流模式转换器之回路带宽（F BW）是由误差放大器输出端的补偿元件来设定，通常设在远低于转换器的开关频率。

电流模式转换器之稳态和负载瞬态变化操作之波形显示于图二。

降压转换器架构之比较图二、电流模式转换器之稳态与负载瞬态的波形降压转换器架构之比较3. 立锜之电流模式- COT（CMCOT）降压转换器立锜之电流模式-COT 降压转换器之内部功能框图显示于图三。

常⽤替换运放型号对⽐常⽤替换运放型号对⽐CA3130 ⾼输⼊阻抗运算放⼤器 Intersil[DATA] CA3140 ⾼输⼊阻抗运算放⼤器 CD4573 四可编程运算放⼤器 MC14573ICL7650 斩波稳零放⼤器 LF347(NS[DATA]) 带宽四运算放⼤器 KA347 LF351 BI-FET单运算放⼤器 NS[DATA] LF353 BI-FET双运算放⼤器 NS[DATA] LF356 BI-FET单运算放⼤器 NS[DATA] LF357 BI-FET单运算放⼤器 NS[DATA] LF398 采样保持放⼤器 NS[DATA] LF411 BI-FET单运算放⼤器 NS[DATA] LF412 BI-FET双运放⼤器 NS[DATA] LM124 低功耗四运算放⼤器(军⽤档) NS[DATA]/TI[DATA] LM1458 双运算放⼤器 NS[DATA] LM148 四运算放⼤器 NS[DATA] LM224J 低功耗四运算放⼤器(⼯业档)NS[DATA]/TI[DATA] LM2902 四运算放⼤器 NS[DATA]/TI[DATA] LM2904 双运放⼤器 NS[DATA]/TI[DATA] LM301 运算放⼤器 NS[DATA] LM308 运算放⼤器 NS[DATA] LM308H 运算放⼤器（⾦属封装） NS[DATA] LM318 ⾼速运算放⼤器NS[DATA] LM324(NS[DATA]) 四运算放⼤器 HA17324,/LM324N(TI) LM348 四运算放⼤器 NS[DATA] LM358 NS[DATA] 通⽤型双运算放⼤器 HA17358/LM358P(TI) LM380 ⾳频功率放⼤器NS[DATA] LM386-1 NS[DATA] ⾳频放⼤器NJM386D,UTC386 LM386-3 ⾳频放⼤器 NS[DATA] LM386-4 ⾳频放⼤器 NS[DATA] LM3886 ⾳频⼤功率放⼤器 NS[DATA] LM3900 四运算放⼤器 LM725 ⾼精度运算放⼤器NS[DATA] LM733 带宽运算放⼤器 LM741 NS[DATA] 通⽤型运算放⼤器HA17741 MC34119 ⼩功率⾳频放⼤器 NE5532 ⾼速低噪声双运算放⼤器 TI[DATA] NE5534 ⾼速低噪声单运算放⼤器TI[DATA] NE592 视频放⼤器 OP07-CP 精密运算放⼤器 TI[DATA] OP07-DP 精密运算放⼤器 TI[DATA] TBA820M ⼩功率⾳频放⼤器 ST[DATA] TL061 BI-FET单运算放⼤器 TI[DATA] TL062 BI-FET双运算放⼤器 TI[DATA] TL064 BI-FET 四运算放⼤器 TI[DATA] TL072 BI-FET双运算放⼤器 TI[DATA] TL074 BI-FET四运算放⼤器 TI[DATA] TL081 BI-FET单运算放⼤器TI[DATA] TL082 BI-FET双运算放⼤器 TI[DATA] TL084 BI-FET四运算放⼤器 TI[DATA] AD824 JFET输⼊,单电源,低电压,低功耗,精密四运算放⼤器 MC33171 单电源,低电压,低功耗运算放⼤器 AD826 低功耗,宽带,⾼速双运算放⼤器 MC33172 单电源,低电压,低功耗双运算放⼤器AD827 低功耗,⾼速双运算放⼤器 MC33174 单电源,低电压,低功耗四运算放⼤器 AD828 低功耗,宽带,⾼速双运算放⼤器 MC33178 ⼤电流,低功耗,低噪⾳双运算放⼤器 AD844 电流反馈型,宽带,⾼速运算放⼤器 MC33179 ⼤电流,低功耗,低噪⾳四运算放⼤器 AD846 电流反馈型,⾼速,精密运算放⼤器 MC33181 JFET输⼊,低功耗运算放⼤器 AD847 低功耗,⾼速运算放⼤器 MC33182 JFET输⼊,低功耗双运算放⼤器AD8531 COMS单电源,低功耗,⾼速运算放⼤器 MC33184 JFET 输⼊,低功耗四运算放⼤器 AD8532 COMS单电源,低功耗,⾼速双运算放⼤器 MC33201 单电源,⼤电流,低电压运算放⼤器AD8534 COMS单电源,低功耗,⾼速四运算放⼤器 MC33202 单电源,⼤电流,低电压双运算放⼤器 AD9617 低失真，电流反馈型,宽带,⾼速,精密运算放⼤器 MC33204 单电源,⼤电流,低电压四运算放⼤器 AD9631 低失真，宽带,⾼速运算放⼤器MC33272 单电源,低电压,⾼速双运算放⼤器 AD9632 低失真，宽带,⾼速运算放⼤器 MC33274 单电源,低电压,⾼速四运算放⼤器 AN6550 低电压双运算放⼤器 MC33282 JFET输⼊,宽带,⾼速双运算放⼤器AN6567 ⼤电流,单电源双运算放⼤器 MC33284 JFET输⼊,宽带,⾼速四运算放⼤器 AN6568 ⼤电流,单电源双运算放⼤器 MC33502 BIMOS,单电源,⼤电流,低电压,双运算放⼤器 BA718 单电源,低功耗双运算放⼤器MC34071A 单电源,⾼速运算放⼤器 BA728 单电源,低功耗双运算放⼤器 MC34072A 单电源,⾼速双运算放⼤器 CA5160 BIMOS,单电源,低功耗运算放⼤器 MC34074A 单电源,⾼速四运算放⼤器 CA5260 BIMOS,单电源双运算放⼤器 MC34081 JFET输⼊,宽带,⾼速运算放⼤器 CA5420 BIMOS,单电源,低电压,低功耗运算放⼤器 MC34082 JFET输⼊,宽带,⾼速双运算放⼤器 CA5470 BIMOS单电源四运算放⼤器 MC34084 JFET输⼊,宽带,⾼速四运算放⼤器CLC400 电流反馈型,宽带,⾼速运算放⼤器 MC34181 JFET输⼊,低功耗运算放⼤器 CLC406 电流反馈型,低功耗,宽带,⾼速运算放⼤器 MC34182 JFET输⼊,低功耗双运算放⼤器 CLC410 电流反馈型,⾼速运算放⼤器 MC34184 JFET输⼊,低功耗四运算放⼤器 CLC415 电流反馈型,宽带,⾼速四运算放⼤器 MC35071A 单电源,⾼速运算放⼤器 CLC449 电流反馈型,宽带,⾼速运算放⼤器 MC35072A 单电源,⾼速双运算放⼤器 CLC450 电流反馈型,单电源,低功耗,宽带,⾼速运算放⼤器 MC35074A 单电源,⾼速四运算放⼤器 CLC452 单电源,电流反馈型,⼤电流,低功耗,宽带,⾼速运算放⼤器 MC35081 JFET输⼊,宽带,⾼速运算放⼤器CLC505 电流反馈型,⾼速运算放⼤器 MC35082 JFET输⼊,宽带,⾼速双运算放⼤器 EL2030 电流反馈型,宽带,⾼速运算放⼤器 MC35084 JFET输⼊,宽带,⾼速四运算放⼤器 EL2030C 电流反馈型,宽带,⾼速运算放⼤器 MC35171 单电源,低电压,低功耗运算放⼤器 EL2044C 单电源,低功耗,⾼速运算放⼤器 MC35172 单电源,低电压,低功耗双运算放⼤器 EL2070 电流反馈型,宽带,⾼速运算放⼤器 MC35174 单电源,低电压,低功耗四运算放⼤器 EL2070C 电流反馈型,宽带,⾼速运算放⼤器 MC35181 JFET输⼊,低功耗运算放⼤器 EL2071C 电流反馈型,宽带,⾼速运算放⼤器 MC35182 JFET输⼊,低功耗双运算放⼤器 EL2073 宽带,⾼速运算放⼤器 MC35184 JFET输⼊,低功耗四运算放⼤器 EL2073C 宽带,⾼速运算放⼤器 MM6558 低电压,低失调电压,精密双运算放⼤器 EL2130C 电流反馈型,宽带,⾼速运算放⼤器MM6559 低电压,低失调电压,精密双运算放⼤器 EL2150C 单电源,宽带,⾼速运算放⼤器 MM6560 低电压,低失调电压,精密双运算放⼤器 EL2160C电流反馈型,宽带,⾼速运算放⼤器 MM6561 低功耗,低电压,低失调电压,精密双运算放⼤器 EL2165C 电流反馈型,宽带,⾼速,精密运算放⼤器 MM6564 单电源,低电压,低功耗,低失调电压,精密双运算放⼤器 EL2170C 单电源,电流反馈型,低功耗,宽带,⾼速运算放⼤器MM6572 低噪⾳,低电压,低失调电压,精密双运算放⼤器 EL2175C 电流反馈型,宽带,⾼速,精密运算放⼤器 NE5230单电源,低电压运算放⼤器 EL2180C 单电源,电流反馈型,低功耗,宽带,⾼速运算放⼤器NE5512 通⽤双运算放⼤器 EL2224 宽带,⾼速双运算放⼤器 NE5514 通⽤四运算放⼤器 EL2224C 宽带,⾼速双运算放⼤器NE5532 低噪⾳,⾼速双运算放⼤器 EL2232 电流反馈型,宽带,⾼速双运算放⼤器NE5534 低噪⾳,⾼速运算放⼤器 EL2232C 电流反馈型,宽带,⾼速双运算放⼤器 NJM2059 通⽤四运算放⼤器 EL2250C 单电源,宽带,⾼速双运算放⼤器 NJM2082 JFET输⼊,⾼速双运算放⼤器 EL2260C 电流反馈型,宽带,⾼速双运算放⼤器 NJM2107低电压,通⽤运算放⼤器 EL2270C 单电源,电流反馈型,低功耗,宽带,⾼速双运算放⼤器 NJM2112 低电压,通⽤四运算放⼤器EL2280C 单电源,电流反馈型,低功耗,宽带,⾼速双运算放⼤器 NJM2114 低噪⾳双运算放⼤器 EL2424 宽带,⾼速四运算放⼤器NJM2115 低电压,通⽤双运算放⼤器 EL2424C 宽带,⾼速四运算放⼤器 NJM2119 单电源,精密双运算放⼤器 EL2444C 单电源,低功耗,⾼速四运算放⼤器 NJM2122 低电压,低噪⾳双运算放⼤器 EL2450C 单电源,宽带,⾼速四运算放⼤器 NJM2130F 低功耗运算放⼤器 EL2460C 电流反馈型,宽带,⾼速四运算放⼤器 NJM2132 单电源,低电压,低功耗双运算放⼤器 EL2470C 单电源,电流反馈型,低功耗,宽带,⾼速四运算放⼤器 NJM2136 低电压,低功耗,宽带,⾼速运算放⼤器 EL2480C 单电源,电流反馈型,低功耗,宽带,⾼速四运算放⼤器NJM2137 低电压,低功耗,宽带,⾼速双运算放⼤器 HA-2640 ⾼耐压运算放⼤器 NJM2138 低电压,低功耗,宽带,⾼速四运算放⼤器 HA-2645 ⾼耐压运算放⼤器 NJM2140 低电压双运算放⼤器 HA-2839 宽带,⾼速运算放⼤器NJM2141 ⼤电流,低电压双运算放⼤器 HA-2840 宽带,⾼速运算放⼤器 NJM2147 ⾼耐压,低功耗双运算放⼤器 HA-2841 宽带,⾼速运算放⼤器 NJM2162 JFET输⼊,低功耗,⾼速双运算放⼤器HA-2842 宽带,⾼速运算放⼤器 NJM2164 JFET输⼊,低功耗,⾼速四运算放⼤器 HA-4741 通⽤四运算放⼤器 NJM3404A 单电源,通⽤双运算放⼤器 HA-5020 电流反馈型,宽带,⾼速运算放⼤器 NJM3414 单电源,⼤电流双运算放⼤器 HA-5127 低噪⾳,低失调电压,精密运算放⼤器 NJM3415 单电源,⼤电流双运算放⼤器 HA-5134 低失调电压,精密四运算放⼤器 NJM3416 单电源,⼤电流双运算放⼤器 HA-5137 低噪⾳,低失调电压,⾼速,精密运算放⼤器 NJM4556A ⼤电流双运算放⼤器 HA-5142 单电源,低功耗双运算放⼤器NJM4580 低噪⾳双运算放⼤器 HA-5144 单电源,低功耗四运算放⼤器 NJU7051 CMOS单电源,低功耗,低电压,低失调电压运算放⼤器 HA-5177 低失调电压,精密运算放⼤器 NJU7052 CMOS单电源,低功耗,低电压,低失调电压双运算放⼤器 HA-5221 低噪⾳,精密运算放⼤器 NJU7054 CMOS单电源,低功耗,低电压,低失调电压四运算放⼤器 HA-5222 低噪⾳,精密双运算放⼤器 NJU7061 CMOS单电源,低功耗,低电压,低失调电压运算放⼤器 HA-7712 BIMOS,单电源,低功耗,精密运算放⼤器NJU7062 CMOS单电源,低功耗,低电压,低失调电压双运算放⼤器 HA-7713 BIMOS,单电源,低功耗,精密运算放⼤器 NJU7064 CMOS单电源,低功耗,低电压,低失调电压四运算放⼤器 HA16118 CMOS单电源,低电压,低功耗双运算放⼤器 NJU7071 CMOS 单电源,低功耗,低电压,低失调电压运算放⼤器 AD704 低偏置电流,低功耗,低失调电压,精密四运算放⼤器 MAX430 CMOS单电源运算放⼤器 AD705 低偏置电流,低功耗,低失调电压,精密运算放⼤器 MAX432 CMOS 单电源运算放⼤器 AD706 低偏置电流,低功耗,低失调电压,精密双运算放⼤器 MAX4330 单电源,低电压,低功耗运算放⼤器 AD707 低失调电压,精密运算放⼤器MAX4332 单电源,低电压,低功耗双运算放⼤器AD708 低失调电压,精密双运算放⼤器 MAX4334 单电源,低电压,低功耗四运算放⼤器 AD711 JFET输⼊,⾼速,精密运算放⼤器 MAX473 单电源,低电压,宽带,⾼速运算放⼤器 AD712 JFET输⼊,⾼速,精密双运算放⼤器 MAX474 单电源,低电压,宽带,⾼速双运算放⼤器 AD713 JFET输⼊,⾼速,精密四运算放⼤器MAX475 单电源,低电压,宽带,⾼速四运算放⼤器AD744 JFET输⼊,⾼速,精密运算放⼤器 MAX477 宽带,⾼速运算放⼤器 AD745 JFET输⼊,低噪⾳,⾼速运算放⼤器 MAX478 单电源,低功耗,精密双运算放⼤器AD746 JFET输⼊,⾼速,精密双运算放⼤器 MAX478A 单电源,低功耗,精密双运算放⼤器 AD795 JFET输⼊,低噪⾳,低功耗,精密运算放⼤器 MAX479 单电源,低功耗,精密四运算放⼤器 AD797 低噪⾳运算放⼤器MAX479A 单电源,低功耗,精密四运算放⼤器 AD8002 电流反馈型,低功耗,宽带,⾼速双运算放⼤器MAX480 单电源,低功耗,低电压,低失调电压,精密运算放⼤器 AD8005 电流反馈型,低功耗,宽带,⾼速双运算放⼤器 MAX492C 单电源,低功耗,低电压,精密双运算放⼤器AD8011 电流反馈型,低功耗,宽带,⾼速运算放⼤器 MAX492E 单电源,低功耗,低电压,精密双运算放⼤器 AD8031 单电源,低功耗,⾼速运算放⼤器 MAX492M 单电源,低功耗,低电压,精密双运算放⼤器 AD8032 单电源,低功耗,⾼速双运算放⼤器MAX494C 单电源,低功耗,低电压,精密四运算放⼤器 AD8041 单电源,宽带,⾼速运算放⼤器 MAX494E 单电源,低功耗,低电压,精密四运算放⼤器 AD8042 单电源,宽带,⾼速双运算放⼤器 MAX494M 单电源,低功耗,低电压,精密四运算放⼤器 AD8044 单电源,宽带,⾼速四运算放⼤器 MAX495C 单电源,低功耗,低电压,精密运算放⼤器 AD8047 宽带,⾼速运算放⼤器 MAX495E 单电源,低功耗,低电压,精密运算放⼤器AD8055 低功耗,宽带,⾼速运算放⼤器 MAX495M 单电源,低功耗,低电压,精密运算放⼤器 AD8056 低功耗,宽带,⾼速双运算放⼤器 MC1458 通⽤双运算放⼤器 AD8072 电流反馈型,宽带,⾼速双运算放⼤器MC1458C 通⽤双运算放⼤器 AD812 电流反馈型,低电压,低功耗,⾼速双运算放⼤器 MC33071A 单电源,⾼速运算放⼤器AD817 低功耗,宽带,⾼速运算放⼤器 MC33072A 单电源,⾼速双运算放⼤器 AD818 低功耗,宽带,⾼速运算放⼤器 MC33074A 单电源,⾼速四运算放⼤器 AD820 JFET输⼊,单电源,低电压,低功耗,精密运算放⼤器 MC33078 低噪⾳双运算放⼤器 AD822 JFET输⼊,单电源,低电压,低功耗,精密双运算放⼤器MC33079 低噪⾳四运算放⼤器 AD823 JFET输⼊,单电源,低电压,低功耗,精密,⾼速双运算放⼤器 MC33102 低功耗双运算放⼤器 HA16119 CMOS单电源,低电压,低功耗双运算放⼤器 NJU7072 CMOS单电源,低功耗,低电压,低失调电压双运算放⼤器 HFA1100 电流反馈型,宽带,⾼速运算放⼤器 NJU7074 CMOS单电源,低功耗,低电压,低失调电压四运算放⼤器 HFA1120 电流反馈型,宽带,⾼速运算放⼤器 OP-07 低漂移,精密运算放⼤器 HFA1205电流反馈型,低功耗,宽带,⾼速双运算放⼤器 OP-113 BICMOS单电源,低噪⾳,低失调电压,精密运算放⼤器 HFA1245 电流反馈型,低功耗,宽带,⾼速双运算放⼤器 OP-150 COMS,单电源,低电压,低功耗 ICL7611 CMOS低电压,低功耗运算放⼤器 OP-160 电流反馈型,⾼速运算放⼤器 ICL7612 CMOS低电压,低功耗运算放⼤器 OP-162 单电源,低电压,低功耗,⾼速,精密运算放⼤器ICL7621 CMOS低电压,低功耗双运算放⼤器 OP-177 低失调电压,精密运算放⼤器 ICL7641 CMOS低电压四运算放⼤器OP-183 单电源,宽带运算放⼤器 ICL7642 CMOS低电压,低功耗四运算放⼤器 OP-184 单电源,低电压,⾼速,精密运算放⼤器ICL7650S 稳压器 OP-191 单电源,低电压,低功耗运算放⼤器 LA6500 单电源，功率OP 放⼤器 OP-193 单电源,低电压,低功耗,精密运算放⼤器 LA6501 单电源，功率OP放⼤器 OP-196 单电源,低电压,低功耗运算放⼤器 LA6510 2回路单电源功率OP放⼤器 OP-200 低功耗,低失调电压,精密双运算放⼤器" LA6512 ⾼压,功率OP放⼤器双运算放⼤器 OP-213 BICMOS单电源,低噪⾳,低失调电压,精密双运算放⼤器 LA6513 ⾼压,功率OP放⼤器双运算放⼤器 OP-250 COMS,单电源,低电压,低功耗双运算放⼤器LA6520 单电源,功率OP放⼤器三运算放⼤器 OP-260 电流反馈型,⾼速双运算放⼤器 LF356 JFET输⼊，⾼速运算放⼤器 OP-262 单电源,低电压,低功耗,⾼速,精密双运算放⼤器 LF356A JFET输⼊，⾼速运算放⼤器 OP-27 低噪⾳,低失调电压,精密运算放⼤器 LF411 JFET输⼊，⾼速运算放⼤器 OP-270 低噪声,低失调电压,精密双运算放⼤器 LF411A JFET输⼊，⾼速运算放⼤器 OP-271 精密双运算放⼤器 LF412 JFET输⼊，⾼速双运算放⼤器 OP-275 ⾼速双运算放⼤器 LF412A JFET输⼊，⾼速双运算放⼤器 OP-279 单电源,⼤电流双运算放⼤器 LF441 低功耗，JFET输⼊运算放⼤器 OP-282 JFET输⼊,低功耗双运算放⼤器 LF441A 低功耗，JFET输⼊运算放⼤器 OP-283 单电源,宽带双运算放⼤器 LF442 低功耗，JFET输⼊双运算放⼤器 OP-284 单电源,低电压,⾼速,精密双运算放⼤器 LF442A 低功耗，JFET输⼊双运算放⼤器OP-290 单电源,低功耗,精密双运算放⼤器 LF444 低功耗，JFET输⼊四运算放⼤器 OP-291 单电源,低电压,低功耗双运算放⼤器 LF444A 低功耗，JFET输⼊四运算放⼤器 OP-292 BICMOS单电源,通⽤双运算放⼤器 LM2902 单电源四运算放⼤器 OP-293 单电源,低电压,低功耗,精密双运算放⼤器 LM2904 单电源双运算放⼤器 OP-295 BICMOS低功耗,精密双运算放⼤器 LM324 单电源四运算放⼤器 OP-296 单电源,低电压,低功耗双运算放⼤器 LM358 单电源双运算放⼤器 OP-297 低电压,低功耗,低漂移,精密双运算放⼤器LM4250 单程控、低功耗运算放⼤器 OP-37 低噪⾳,低失调电压,⾼速,精密运算放⼤器 LM607 低失调电压,精密运算放⼤器 OP-400 低功耗,低失调电压,精密四运算放⼤器 LM6118 宽带,⾼速双运算放⼤器OP-413 BICMOS单电源,低噪⾳,低失调电压,精密四运算放⼤器。

600KHz 36V/1.2A Synchronous Step-down ConverterGeneral DescriptionThe LP6498A is a synchronous step-down regulatorfromahighvoltageinputsupply.Operating with an input voltage range from 4.5V to 30V.1.2A continuous output current .The converter integrates a main switch and a synchronous rectifier for high efficiency without an external Schottky diode. LP6498A Requires a minimum number of readily available standard external components.over current protection and thermal shutdown . output short circuit protection. The LP6498A converters are available in the industry standard SOT23-6 packages.Order InformationLP6498A□ □ □F: Pb-FreePackage TypeB6:SOT23-6Applications✧ Car Charger / Adaptor✧ Pre-Regulator for Linear Regulators ✧ Distributed Power Systems✧ USB Dedicated Charging Ports (DCP)Features◆ Input Voltage Range: 4.5V to 30V ◆ Output Voltage Range: 0.8V to 12V◆ 1200mA Load Current ◆ Up to 93% Efficiency◆ 600KHz Switching Frequency◆ Short Circuit Protection ◆ Thermal Fault Protection ◆ S O T 23-6 Package◆ RoHS Compliant and 100% Lead (Pb)-FreeTypical Application CircuitMarking InformationVINFunctional Pin DescriptionPin DescriptionNC No connection.GND Ground.FB Feedback Input.Vout=(R1R2+1)×V FBFunction DiagramAbsolute Maximum Ratings✧VIN\SW \EN to GND ---------------------------------------------------------------------------------------------- -0.3V to 36V ✧VOUT\LED\RV\FB to GND --------------------------------------------------------------------------------------- -0.3V to 6.5V ✧Maximum Junction Temperature -------------------------------------------------------------------------------------- 150°C ✧Storage Temperature ------------------------------------------------------------------------------------------ -65℃ to 165℃✧Operating Ambient Temperature Range (TA) ------------------------------------------------------------- -20℃ to 85°C ✧Maximum Soldering Temperature (at leads, 10 sec) ------------------------------------------------------------- 260°CNote 1. Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied.Exposure to absolute maximum rating conditions for extended periods may affect device reliability.Thermal Information✧Maximum Power Dissipation (SOT23-6, P D, T A=25℃) ------------------------------------------------------------ 0.6W ✧Thermal Resistance (SOT23-6, θJA) ------------------------------------------------------------------------------ 200℃/W ESD Susceptibility✧HBM(Human Body Mode) -------------------------------------------------------------------------------------------------- 2KV ✧MM(Machine Mode) --------------------------------------------------------------------------------------------------------- 200VElectrical CharacteristicsV IN=12V, V EN=5V, T A=25℃, unless otherwise notedHiccup Time 6Soft-start Time0.8Oscillator Frequency 600Typical Operating CharacteristicsOperation InformationFunctional DescriptionThe LP6498A is a switch-mode step-down DC-DC converter. The device operates at a fixed 600KHz switching frequency, and uses a slope compensated current mode architecture. This step-down DC-DC converter can supply up to 1.2A output current at input voltage range from 4.5V to 30V. It minimizes external component size and optimizes efficiency at the heavy load range. The integrated slope compensation allows the device to remain stable over a wider range of inductor values so that smaller values (6.8μH to 22μH) with lower DCR can be used to achieve higher efficiency. Layout GuidanceWhen laying out the PCB board, the following layout guideline should be followed to ensure proper operation of the LP6498A:1. The power traces, including the GND trace, the SW trace and the IN trace should be kept short, direct and wide to allow large current flow. The L connection to the SW pins should be as short as possible. Use several VIN pads when routing between layers.2. The input capacitor (C IN) should connect as closely as possible to VIN and GND to get good power filtering.Packaging InformationSOT23-6。

典型应用电路INTVCC R TOP1C C1R C1C SS1C INTC DRVC IN1C BST1C BST2L1M1M2L2V INV INV OUT1C OUT1C OUT2V OUT2R BOT1R TOP2R C2C C2C SS2C IN2R BOT2R OSCF B 1C O M P 1S S 1E N 1P V I N 1B S T 1F B 2C O M P 2S S 2E N 2P V I N 2B S T 2MODE SCFG TRK2TRK1VDRV ADP2323GND PGOOD2PGOOD1SYNCRTSW1DL1PGND DL2SW209357-001图1.5055606570758085909510000.51.01.52.02.53.0E F F I C I E N C Y (%)OUTPUT CURRENT (A)V OUT = 5V V OUT = 3.3V09357-002图2.效率与输出电流的关系(V IN = 12 V ，f SW = 600 kHz)双通道、3 A 、20 V 同步降压调节器，集成高端MOSFET 数据手册ADP2323产品特性输入电压：4.5 V 至20 V 输出精度：±1%集成典型值90 mΩ的高端MOSFET 灵活的输出配置双路输出：3 A/3 A 单路交错式输出：6 A可编程开关频率：250 kHz 至1.2 MHz外部同步输入，可编程相移，或内部时钟输出可选PWM 或PFM 工作模式小型电感的限流可调外部补偿和软启动启动后进入预充电输出受ADIsimPower ™设计工具支持应用通信基础设施网络和服务器工业和仪器仪表医疗保健中间供电轨转换DC-DC 负载点应用概述ADP2323是一款功能全面的双通道降压DC-DC 调节器，采用电流模式架构。

ADP2323集成两个高端功率MOSFET 开关和两个低端驱动器，可控制外部的N 沟道MOSFET 。

ReclosersFunctional Specification GuideTypes VSA12, VSA16 and VSA20 ReclosersPS280014EN1 of 3 • Effective June 2017 • Supersedes all previousFunctional specification for Types VSA12, VSA16 and VSA20 reclosers1. Equipment Specifications1.1. Automatic circuit reclosers with vacuum interruption and air insulation2. Standards2.1. The recloser covered by this specification shall be designed, manufactured and tested in accordance withapplicable ANSI C37.60 and ANSI C37.61. 3. Quality3.1. The manufacturing facility shall be independently certified to meet ISO 9001 Standards.4. RatingsVSA12 VSA16 VSA20 Maximum Design Voltage (kV) 15.5 15.5 15.5 Nominal Operating Voltage (kV) 2.4-14.42.4-14.42.4-14.4 Basic Insulation Level-BIL (kV) 110 110 110 60 Hertz Withstand Voltage (kV) Dry, one minute 50 50 50Wet, ten seconds45 45 45 Max RIV at 1.0 MHZ/9.41 kV (microvolts) 100 100 100 Continuous Current rating (amps) 800 800 800 Symmetric Interrupting Current (amps)12,000 16,00020,000 Cable Charging Current (amps) 2 2 2 Magnetizing Current (amps) 28 28 28 General Purpose Capacitance Current 250 250 250Switching (amps)3 Second Current, Symmetric (amps) 12,000 16,000 20,000 Momentary Current, Asymmetric (amps) 19,20025,60032,0005. Mechanical Life5.1. 2500 Close-Open operations6. Duty cyclePERCENT OF NUMBER OF MAXIMUM INTERRUPTING UNIT CIRCUIT RATING OPERATIONS X/R RATIO 15-2088445-55 112 890-100 32 167. Features7.1. The recloser will be mechanically and electrically trip-free7.2. All three poles of the recloser will be operated simultaneously by a solenoid-spring operating mechanism.7.3. The recloser will be opened and closed by means of energy provided by a motor operating at 240 Vac, 60Hz and stored in springs for both tripping and closing operations.7.4. Bushings will be of “wet” process porcelain and will have a standard creepage distance of 12" inches. A17" creepage distance bushing will be available as an option.7.5. Bushing terminals will be of the universal clamp type and will accommodate conductors ranging in sizefrom 4/0 to 1000 MCM, inclusive,7.6. Current interruption will occur in vacuum interrupters, one interrupter per phase.7.7. It will be possible to replace one or all bushings without any re-alignment or adjustment of the vacuuminterrupters or operating mechanism.7.8. The recloser interrupting time will be 0.042 seconds7.9. Resistance-type heaters will be provided in the interrupter and operating mechanism cabinets, to preventmoisture condensation.7.10. The recloser will be shipped mounted in a substation mounting frame.7.11. The mounting frame extension will have a ground pad which will accommodate two No. 2/0 to 250 MCMconductors7.12. Sensing bushing current transformers, 1000:1 ratio, for use with the recloser control, will be mountedinternally in the recloser on bushings 1, 3, and 5.7.13. A 4 - digit counter will be provided in the operating mechanism.7.14. The recloser will use a motor operator to charge opening and closing springs; solenoids will be used forthe tripping and closing operations.7.15. A contact position indicator, externally visible, will be provided.7.16. Two external pull rings will be provided, one to close the recloser and one to trip the recloser.7.17. A spring operator condition indicator will be provided to indicate whether the closing springs are energized.The indicator consists of a mechanical flag for indication and will be visible from the front of the operatorcabinet.7.18. The recloser will be capable of manual trip and manual close on a maximum fault. Closing springs can becharged manually by means of a crank (150 turns), through a gear box.8. Spring Charging MotorSTANDARD ACCESSORYOperating voltage (Vac) 240 120Voltage Range (Vac) 160-257 90-127Maximum Current RMSA (amperes) 13 18Steady State Current (amperes) 8 9Motor Running Time (cycles) 40 409. Controls9.1. The recloser will be capable of operation with any of the following: Form 3, Form 3A, Form 4A or Form 4CType ME Recloser control.10. Approved ManufacturersEaton。

2A, 18V 同步整流降压转换器概述AP2952是一款单片同步整流降压稳压器，它集成了导通阻抗130mΩ的MOSFET，可以在很宽的输入电压范围（4.75V-18V）内提供2A的负载能力。

电流模式控制使其具有很好的瞬态响应和单周期内的限流功能。

可调的软启动时间能避免开启瞬间的冲击电流，在停机模式下，输入电流小于1uA。

AP2952封装为SOP8, 同时提供了紧凑的系统方案，可以最大限度的减少外围元件。

应用z分立式电源系统z网络系统z FPGA, DSP, ASIC电源z绿色电子产品z笔记本电脑特性z2A输出电流z输入电压范围4.75V到18Vz内部集成130mΩ的功率MOSFETz输出可调范围为0.925V到15Vz效率可达95%z可调软启动时间z外围使用低ESR瓷片电容可保证其稳定工作z固定的450kHz工作频率z每个周期内都有限流功能z具有欠压保护功能z散热能力较强的SOP8封装封装SOP8典型应用电路图图1 典型应用电路图典型效率曲线1200图2 典型效率曲线引脚说明引脚序号 引脚名称引脚描述1BS 上管栅极驱动升压输入。

BS 为上管N 沟道MOSFET 开关提供驱动。

从SW 到BS 端连接一个0.01uF 或更大的电容。

2IN电源输入。

为IC 以及降压转换器开关提供输入电源。

在4.75V 至18V 的电压范围驱动IN 。

通过一个适当的大电容旁路IN 到地，以消除输入IC 的噪声。

3SW 功率开关输出。

SW 为开关节点提供电源输出。

从SW 端到输出负载连接输出LC 滤波器。

请注意，从SW 到BS 需要接一个电容。

4 GND 电源地。

5FB反馈输入端。

FB 侦测输出电压来调节这个电压。

通过来自输出电压的一个电阻分压器驱动FB 。

反馈阈值电压是0.925V 。

6COMP 补偿节点。

COMP 用来补偿调节控制回路。

从COMP 脚到GND 连接一个RC 网络来补偿调节控制回路。

在某些情况下，从COMP 到GND 之间必须接一个额外的电容。

降压型开关稳压电源控制器概述AE2576是降压型开关稳压器，具有非常小的电压调整率和电流调整率，具有3A的负载驱动能力，AE2576能够输出3.3V、5V、12V、15V的固定电压和电压可调节的可调电压输出方式。

AE2576应用时比较简单且外围元件较少，内置频率补偿电路和固定频率振荡器。

AE2576系列产品的开关频率为52KHz，所以应用时可以使用小尺寸的滤波元件。

AE2576可以高效的取代一般的三端线性稳压器，它能够充分的减小散热片的面积，在一些应用条件下甚至可以不使用散热片。

在规定的输入电压和输出负载的条件下，AE2576输出电压的误差范围为±4％；振荡器的振荡频率误差范围为±10％；典型的待机电流为50μA，芯片内置过流保护电路和过热保护电路。

特点■ 3.3V、5V、12V、15V的固定电压输出和可调节电压输出■可调节电压输出的范围为1.23V到30V，其线性调整率和负载调整率最大可以有±4％的误差。

■负载电流达到3A■输入电压达到36V■只需四个外围元件■内置固定频率为52kHz的振荡器■高效率■内置过热保护电路和过流保护电路应用领域■高效降压型调节器■正、负电压转换器典型应用图图1：固定电压输出模式功能框图3.3v R2=1.7K 5v R2=3.1K 12v R2=8.4K15v R2=11.3K For Adjustable R2=0K R1=open 管脚图5-Lead TO-220(T) 5-Lead TO-263(S)管脚说明：V IN ― 正电源输入；为减小输入瞬态电压和给调节器提供开关电流，此管脚应接旁路电容V OUT ― 开关输出端，输出高电压为（V IN －V SAT ）GND ― 电路地端FEEDBACK― 反馈端― 待机端，低电平有效最大绝对额定值(注1)名 称范 围单 位最大电源电压 45 V脚输入电压-0.3～+ V IN V 到地的输出电压（静态） -1 V功 耗由内部限定 --储存温度 -65～+150℃最高工作结温 +150 ℃ESD 保护能力（人体放电）2 KV 气 焊（60秒）+215 ℃ TO-263 红外线焊接（10秒）+245 ℃ 焊接时的管脚温度 TO-220电烙铁焊接（10秒）+260℃ 温度范围 -40～+125℃工 作 条 件 电源电压 4.5～40 VAE2576-3.3 电气特性(说明：本参数适合于芯片结温T J =25℃)AE2576-3.3符 号参数说明条 件最小(注2)典型最大 (注2)单位系统参数 测试电路见图2(注3)V OUT 输出电压 6V ≤V IN ≤36V 0.5A ≤I LOAD ≤3A 3.168 3.3 3.432Vη 效率V IN =12V ，I LOAD =3A-- 75 -- %AE2576技术说明书 Ver1.0AE2576-5电气特性(说明：本参数适合于芯片结温T J=25℃)AE2576-5.0符号参数说明条件最小(注2) 典型最大(注2)单位系统参数测试电路见图2(注3)V OUT 输出电压8V≤V IN≤36V0.5A≤I LOAD≤3A4.800 55.200 Vη效率V IN=12V，I LOAD=3A-- 77 -- %AE2576-12电气特性(说明：本参数适合于芯片结温T J=25℃)AE2576-12符号参数说明条件最小(注2) 典型最大(注2)单位系统参数测试电路见图2(注3)V OUT 输出电压15V≤V IN≤36V0.5A≤I LOAD≤3A11.520 12 12.480 Vη效率V IN=15V，I LOAD=3A-- 88 -- %AE2576-15电气特性(说明：本参数适合于芯片结温T J=25℃)AE2576-12符号参数说明条件最小(注2) 典型最大(注2)单位系统参数测试电路见图2(注3)V OUT 输出电压18V≤V IN≤36V0.5A≤I LOAD≤3A14.400 15 15.600 Vη效率V IN=18V，I LOAD=3A-- 88 -- %AE2576-ADJ 电气特性(说明：本参数适合于芯片结温T J =25℃)AE2576-ADJ符 号参数说明条 件最小 (注2)典型最大 (注2)单位系统参数 测试电路见图2(注3)FB反馈电压 8V ≤V IN ≤36V 0.5A ≤I LOAD ≤3A V OUT =5V (见图2) 1.193 1.230 1.267Vη 效率V IN =12V ，I LOAD =3A V OUT =5V-- 77 -- %整体电特性除非特别说明，V IN =12V 适应于V OUT =3.3V 、5V 、ADJ ；V IN =25V 适应于V OUT =12V ，V IN =30V适应于VOUT =15V 。

RT4720ATriple DC/DC Boost Converter for AMOLEDGeneral DescriptionRT4720A is a triple channels DC/DC converter which is designed to provide the power of AMOLED. It integrates step up DC/DC and an inverting converter to provide the positive and negative output voltage required by AMOLED.For the portable application, board space and efficiency are always major concerns. The high switching frequency of RT4720A allows the use of low inductance inductor to save the board space. It provides dual positive output voltage, one is a fixed 5.8V or 7.7V output voltage by SEL pin and the other positive output is fixed 4.6V. For the negative output voltage, it can be programmed by external MCU through single wire (SWIRE pin). The output voltage range of negative output voltage is -1.4V to -5.4V. RT4720A has OTP, SCP, UVLO and over current protections. The RT4720A is available in a WQFN -16L 3x3 package to achieve saving PCB space.Features●Boost Converter to Supply Positive AVDD Voltage Fixed 5.8V or 7.7V●Boost Converter to Supply AMOLED Positive Voltage 4.6V●Inverter Converter to Supply AMOLED Negative Voltage From -1.4V to -5.4V● Maximum Output Current up to 300mA for AMOLED Positive & Negative Power Supply●Maximum Output Current up to 50mA for Fixed 5.8V or 7.7V AVDD Output Voltage● Typical Peak Efficiency : 90% (40mA to 150mA) ● ********************************● High Output Voltage Accuracy ● Excellent Line and Load Transient ● Excellent Line and Load Regulation● Programmable Negative Voltage by SWIRE Pin ● Fast Outputs Discharge Function● Low Quiescent Current <1 A in Shutdown Mode ● Internal Soft Start to limit Inrush Current ● Over Temperature Protection (OTP) ● Over Current Protection (OCP) ●Short Circuit Protection (SCP)Applications● Cellular Phones ● Digital Cameras ● PDAs and Smart Phones ●Probable InstrumentSimplified Application CircuitVBAT V POSAVDD V NEGRT4720AOrdering InformationPackage TypeQW : WQFN-16L 3x3RT4720ALead Plating SystemG : Green (Halogen Free and Pb Free)Note :Richtek products are :④ RoHScompliant and compatible with the current requirements of IPC/JEDEC J-STD-020.④ Suitablefor use in SnPb or Pb-free solderingprocesses.Marking Information7Y= : Product Code YMDNN : Date CodePin Configurations(TOP VIEW)A V I N P G N D 2L X 3S E L LX1PGND1FBSLX2V O 3PVIN VO2N C E N O 3A G N D VO1SWIRE1211109131415161234876517AGNDWQFN-16L 3x3Functional Pin DescriptionRT4720AFunctional Block DiagramOperationThe RT4720A is a triple channels DC/DC converter which is designed to provide the power of AMOLED that can support the input voltage range from 2.9V to 4.5V. The VO1&VO2 output current can be up to 300mA, and the VO3 output current can be up to 50mA. The RT4720A uses current mode architecture for the purpose of high efficiency and high transient response. The VO1 positive output voltage is produced from the DC/DC Boost converter and is set at a typical value of 4.6V. When the SWIRE goes high, the positive output voltage will be enabled with an internal soft-start process. The VO2 negative output voltage is produced from the DC/DC Buck-Boost converter and the negative output voltage range is -1.4V to -5.4V. It can be programmed by external MCU through single wire (SWIRE pin). The VO3 positive output voltage is produced from the DC/DC Boost converter and is set at a fixed 7.7V or 5.8V by SEL pin. When SWIRE goes high and VO1 soft-start had finished already, negative output voltage VO2 will be enabled with an internal soft-start process.RT4720ATable 1. SWIRE Command LUT for VO2Table 2. SWIRE Pin CharacteristicsRT4720ATiming DiagramSWIRE Command Timing DiagramT en_dly< 400μs2μs < T off < 20μsPower SequenceT off_dly > 300μsRT4720AT> 300 sRT4720A Absolute Maximum Ratings(Note 1)●PVIN, AVIN, VO1, LX1, FBS, SEL, ENO3, SWIRE ----------------------------------------------------------- -0.3 to 6V●VO3, LX3 ---------------------------------------------------------------------------------------------------------------- -0.3 to 12V●VO2 ----------------------------------------------------------------------------------------------------------------------- -6 to 0.3V●LX2 ------------------------------------------------------------------------------------------------------------------------ -6 to 6V●Power Dissipation, P D @ T A = 25︒CWQFN-16L 3x3 -------------------------------------------------------------------------------------------------------- 3.33W●Package Thermal Resistance (Note 2)WQFN-16L 3x3, θJA -------------------------------------------------------------------------------------------------- 30︒C/WWQFN-16L 3x3, θJC -------------------------------------------------------------------------------------------------- 7.5︒C/W●Lead Temperature (Soldering, 10 sec.) -------------------------------------------------------------------------- 260︒C●Junction Temperature ------------------------------------------------------------------------------------------------ 150︒C●Storage Temperature Range --------------------------------------------------------------------------------------- -65︒C to 150︒C ●ESD Susceptibility (Note 3)HBM (Human Body Model) ----------------------------------------------------------------------------------------- 2kVMM (Machine Model) ------------------------------------------------------------------------------------------------- 200V Recommended Operating Conditions (Note 4)●Supply Input Voltage ------------------------------------------------------------------------------------------------- 2.9V to 4.5V●Ambient Temperature Range--------------------------------------------------------------------------------------- -40︒C to 85︒C ●Junction Temperature Range -------------------------------------------------------------------------------------- -40︒C to 125︒C Electrical Characteristics(V IN = 3.7V, V O1 = 4.6V, V O2 = -4V, V O3 = 7.7V, T A = 25︒C, unless otherwise specified)RT4720ART4720A Note 1. Stresses beyond those listed “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions may affect device reliability.Note 2. θJA is measured at T A= 25︒C on a high effective thermal conductivity four-layer test board per JEDEC 51-7. θJC is measured at the exposed pad of the package.Note 3. Devices are ESD sensitive. Handling precaution recommended.Note 4. The device is not guaranteed to function outside its operating conditions.RT4720ATypical Application CircuitVBAT V POS(Fixed 4.6V)AVDD (5.8V & 7.7V)V NEGTable 3. Typical BOM ListTypical Operating CharacteristicsVO1&VO2 Efficiency vs. Load Current707580859095100E f f i c i e n c y (%)VO3 Efficiency vs. Load Current6065707580859095100E f f i c i e n c y (%)4.564.574.584.594.604.614.624.634.64V P O S V o l t a g e (V )VNEG Voltage vs. Load Current-4.04-4.03-4.02-4.01-4.00-3.99-3.98-3.97-3.9600.050.10.150.20.250.3Load Current (A)V N E G V o l t a g e (V )7.667.677.687.697.707.717.727.737.7401020304050Loader Current (mA)A V D D V o l t a g e (V )V IN = 3.7VSWIRE (2V/Div)VO1(2V/Div)VO2(2V/Div)I IN(500mA/Div)Time (1ms/Div)VO1 & VO2 Power OnVO1 & VO2 Power OffTime (1ms/Div)SWIRE (2V/Div)VO1(2V/Div)VO2(2V/Div)I IN(500mA/Div)V IN = 3.7VVO3 Power OnTime (1ms/Div)VIN (2V/Div)ENO3(2V/Div)VO3(3V/Div)I IN(500mA/Div)V IN = 3.7VVO3 Power OffTime (1ms/Div)V IN = 3.7VVIN (2V/Div)ENO3(2V/Div)VO3(3V/Div)I IN(500mA/Div)Application InformationThe RT4720A is a triple channels DC/DC converter, which integrates dual step up converter and an inverting converter to provide the positive and negative output voltage required by AMOLED. RT4720A protection function includes Over Temperature Protection (OTP), Over Current Protection (OCP) and Short Circuit Protection (SCP), also it has Pulse Skipping Mode (PSM) to provide high efficiency during light load.Soft-StartThe RT4720A use an internal soft-start feature to avoid high inrush currents during step-up.Fast Discharge FunctionAll outputs voltage use an embedded discharge function to discharge the remaining output to 0V rapidly, preventing phenomena such as residual image on the display during shutdown.Over Temperature Protection (OTP)The RT4720A includes an Over Temperature Protection (OTP) feature to prevent excessive power dissipation from overheating the device. The OTP will shut down switching operation when junction temperature exceeds 140︒C. Once the junction temperature cools down by approximately 15︒C, the converter resumes operation.To maintain continuous operation, prevent the maximum junction temperature from rising above 125︒C.Over Current Protection (OCP)The RT4720A includes a current sensing circuitry which monitors the inductor current during each ON period. If the current value becomes greater than the current limit, the switch that pertains to inductor charging will turn off, forcing the inductor to leave charging stage and enter discharge stage.Short Circuit Protection (SCP)The RT4720A has an advanced short circuit protection mechanism which prevents damage to the device from unexpected applications. When the output voltage becomes lower than about 90%, over 1ms the device enters shutdown mode. VO3 can only re-start normal operation after triggering the ENO3 pin and VO1, VO2 can only re-start normal operation after triggering the SWIRE pin.Under Voltage Lockout (UVLO)To prevent abnormal operation of the IC in low voltage condition, an under voltage lockout is included, which shuts down the device at voltages lower than 2.2V. All functions will be turned off in this state.Input Capacitor SelectionEach channel input ceramic capacitors with 10μF capacitance are suggested for the RT4720A applications. However, to achieve best performance with the RT4720A, larger capacitance can be used. For better voltage filtering, select ceramic capacitors with low ESR, X5R and X7R types which are suitable because of their wider voltage and temperature ranges.Boost Inductor SelectionThe inductance depends on the maximum input current. As a general rule, the inductor ripple current range is 20% to 40% of the maximum input current. If 40% is selected as an example, the inductor ripple current can be calculated according to the following equations :OUT OUT(MAX)IN(MAX)INL IN(MAX)V II=ηVΔI= 0.4I⨯⨯⨯where η is the efficiency of the converter, I IN(MAX) is the maximum input current, and ΔI L is the inductor ripple current. The input peak current can then be obtained by adding the maximum input current with half of the inductor ripple current as shown in the following equation :I PEAK = 1.2×I IN(MAX)Note that the saturated current of the inductor must be greater than I PEAK.The inductance can eventually be determined according to the following equation :()()()2IN OUT IN2OUT OUT(MAX)OSCηV V-VL =0.4V I f⨯⨯⨯⨯⨯where f OSC is the switching frequency. For better system performance, a shielded inductor is preferred to avoid EMI problems.Boost Output Capacitor SelectionThe output ripple voltage is an important index for estimating chip performance. This portion consists of two parts. One is the product of the inductor peak current with the ESR of the output capacitor, while the other part is formed by the charging and discharging process of the output capacitor. As shown in Figure 1, ΔV OUT1 can be evaluated based on the ideal energy equalization. According to the definition of Q, the Q value can be calculated as the following equation :IN L OUT IN L OUT IN OUT OUT1OUT OSC111Q = I +ΔI -I +I -ΔI -I 222V 1= C V V f ⎡⎤⎛⎫⎛⎫⨯ ⎪ ⎪⎢⎥⎝⎭⎝⎭⎣⎦⨯⨯⨯where f OSC is the switching frequency and ΔI L is the inductor ripple current. Bring C OUT to the left side to estimate the value of ΔV OUT1 according to the following equation :OUTOUT1ESR OUT OSCD I ΔV = ΔV +ηC f ⨯⨯⨯where ESR C C_ESR PEAK C_ESR ΔV = ΔI R = I R ⨯⨯The output capacitor, C OUT , should be selected accordingly.Figure 1. The Output Ripple Voltage without theContribution of ESRAVDD Output Voltage SettingThe AVDD boost output voltage VO3 is fixed 7.7V or 5.8V output voltage by SEL pin. When SEL pin is set to high, the output voltage is 5.8V or otherwise SEL pin is set to low, the output voltage is changed to 7.7V.Buck-boost Converter Inductor SelectionThe first step in the design procedure is to verify whether the maximum possible output current of the buck-boost converter supports the specific application requirements. To simply the calculation, the fastest approach is to estimate converter efficiency by taking the efficiency numbers from provided efficiency curves or to use a worst case assumption for the expected efficiency, e.g., 80%. The calculation must be performed for the minimum assumed input voltage where the peak switch current is the highest. The inductor has an internal switch to be able to handle this current.④Converter Duty Cycle :OUT IN OUT-V D =V η-V ⨯④Maximum output current :()IN OUT PEAK OSC V D I = I -1-D 2f L ⎛⎫⨯⨯ ⎪⨯⨯⎝⎭④Inductor peak current :OUT IN PEAK OSC I V DI =+1-D 2f L⨯⨯⨯ As for inductance, we are going to derive the transition point, where the converter toggles from CCM to DCM. We need to define the point at which the inductor current ripple touches zero, and as the power switch SW is immediately reactivated, the current ramps up again. Figure 2 portrays the input current activity of the buck-boost converter.Figure 2. The Buck-Boost Input Signature in BCM The inductance can eventually be determined according to the following equation :2OUT INcritical OSC OUT IN OUTV ηV L = 2f I V +V ⎛⎫⨯⨯⎪ ⎪⨯⨯⎝⎭Buck-Boost Converter Output Capacitor Selection For the best output voltage filtering, low ESR ceramic capacitors are recommended. One 10μF output capacitors with sufficient voltage ratings in parallel are adequate for most applications. Additional capacitors can be added to improve load transient response. To calculate the output voltage ripple, the following equations can be used :OUT ESR OSC LOAD OUTD V ΔV =+ΔV f R C ⨯⨯⨯where ESR C C_ESR PEAK C_ESR ΔV = ΔI R = I R ⨯⨯ΔV ESR can be neglected in many cases since ceramic capacitors provides very low ESR.Negative Output Voltage SettingBuck-boost converter is implementing a pulse dimming method to control the output voltage (VO2) and its value is from -1.4V to -5.4V in 0.1V increments. User can control VO2 by SWIRE command. See SWIRE command section for details on how to adjust the output voltage.Thermal ConsiderationsFor continuous operation, do not exceed absolute maximum junction temperature. The maximum power dissipation depends on the thermal resistance of the IC package, PCB layout, rate of surrounding airflow, and difference between junction and ambient temperature. The maximum power dissipation can be calculated by the following formula : P D(MAX) = (T J(MAX) - T A ) / θJAwhere T J(MAX) is the maximum junction temperature, T A is the ambient temperature, and θJA is the junction to ambient thermal resistance.For recommended operating condition specifications, the maximum junction temperature is 125︒C. The junction to ambient thermal resistance, θJA , is layout dependent. For WQFN-16L 3x3 package, the thermal resistance, θJA , is 30︒C/W on a standard JEDEC 51-7 four-layer thermal test board. The maximum power dissipation at T A = 25︒C can be calculated by the following formula :P D(MAX) = (125︒C - 25︒C) / (30︒C/W) = 3.33W for WQFN-16L 3x3 packageThe maximum power dissipation depends on the operating ambient temperature for fixed T J(MAX) and thermal resistance, θJA . The derating curve in Figure 3 allows the designer to see the effect of rising ambient temperature on the maximum power dissipation.Figure 3. Derating Curve of Maximum PowerDissipationLayout ConsiderationFor the best performance of RT4720A, thefollowing PCB layout guidelines should be strictly followed.④ For good regulation, place the power components asclose to the IC as possible. The traces should be wide and short, especially for the high current output loop.④ The input and output bypass capacitor should be placed as close to the IC as possible and connected to the ground plane of the PCB.④ Minimize the size of the LX1, LX2, LX3 nodes andkeep the traces wide and short. Care should be taken to avoid running traces that carry any noise-sensitive signals near LX or high-current traces.④ Separate power ground (PGND) and analog ground (AGND). Connect the AGND and the PGND islands at a single end. Make sure that there are no otherconnections between these separate ground planes. ④ Connect the exposed pad to a strong ground planefor maximum thermal dissipation.0.00.40.81.21.62.02.42.83.23.64.00255075100125Ambient Temperature (°C)M a x i m u m P o w e r D i s s i p a t i o n (W )Figure 4. PCB Layout GuideOutline DimensionW-Type 16L QFN 3x3 PackageRichtek Technology Corporation14F, No. 8, Tai Yuen 1st Street, Chupei CityHsinchu, Taiwan, R.O.C.Tel: (8863)5526789Richtek products are sold by description only. Richtek reserves the right to change the circuitry and/or specifications without notice at any time. Customers should obtain the latest relevant information and data sheets before placing orders and should verify that such information is current and complete. Richtek cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Richtek product. Information furnished by Richtek is believed to be accurate and reliable. However, no responsibility is assumed by Richtek or its subsidiaries for its use; nor for any infringements of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Richtek or its subsidiaries.。

Roland van RoyAN032 – Jan 20151. 简介 (2)2. 电流模式降压转换器 (2)3. 立锜之电流模式- COT（CMCOT）降压转换器 (4)4. 立锜之ADVANCED-COT (ACOT TM) 降压转换器 (5)5. 测量结果比较 (7)6. 总结 (10)降压转换器架构之比较1. 简介降压转换器被广泛应用于各种消费性和工业上的应用之中，其中常需转换器将较高的输入电压转换成一较低的输出电压。

现有的降压转换器效率非常好，并能在变化范围很大的输入电压和输出负载的条件下，仍产生调节良好的输出电压。

降压转换器有很多不同的回路控制方式：在过去，被广泛使用的是电压模式和电流模式，然而近来恒定导通时间（COT）架构也常被使用，而有些降压转换器则是同时由电流模式和恒定导通时间来控制的。

立锜的DC-DC 产品组合包含了多种降压转换器，包括电流模式（CM），电流模式-恒定导通时间（CMCOT）和先进恒定导通时间（ACOT™）等架构。

每种架构都有其优点和缺点，因此在实际应用中要选择降压转换器时，最好能先了解每种架构的特点。

2. 电流模式降压转换器电流模式降压转换器之内部功能框图显示于图一。

图一、电流模式转换器之内部功能框图在典型的电流模式控制中，会有一个恒定频率来启动高侧MOSFET，并有一误差放大器将反饋信号与参考电压作比较。

然后，电感电流的上升斜率再与误差放大器的输出作比较；当电感电流超过误差放大器的输出电压时，高侧MOSFET 即被关断(OFF)，而电感电流则流经低侧MOSFET，直等到下一个时钟来到。

电流斜坡再加上斜率补偿之斜坡是为要避免在高占空比时的次谐波振荡，并提高抗噪声性能。

电流模式转换器之回路带宽（F BW）是由误差放大器输出端的补偿元件来设定，通常设在远低于转换器的开关频率。

电流模式转换器之稳态和负载瞬态变化操作之波形显示于图二。

降压转换器架构之比较图二、电流模式转换器之稳态与负载瞬态的波形降压转换器架构之比较3. 立锜之电流模式- COT（CMCOT）降压转换器立锜之电流模式-COT 降压转换器之内部功能框图显示于图三。

ANPEC reserves the right to make changes to improve reliability or manufacturability without notice, and advise customers to obtain the latest version of relevant information to verify before placing orders.FeaturesGeneral Description•Wide Input Voltage from 4.5V to 24V •2A Continuous Output Current•Adjustable Output Voltage from 0.92V to 20V •Intergrated N-MOSFET•Fixed 340kHz Switching Frequency •PFM/PWM mode Operation •Stable with Low ESR Capacitors •Power-On-Reset Detection •Programmable Soft-Start •Over-Temperature Protection •Over-Voltage Protection•Current-Limit Protection with Frequency Foldback •Enable/Shutdown Function •Small SOP-8P Package•Lead Free and Green Devices Available(RoHS Compliant)Applications•LCD Monitor/TV •Set-Top Box• DSL, Switch HUB• Notebook ComputerAPW7302B is a 2A synchronous buck converter with inte-grated power MOSFETs. The APW7302B design with a current-mode control scheme, can convert wide input voltage of 4.5V to 24V to the output voltage adjustable from 0.92V to 20V to provide excellent output voltage regulation.The APW7302B is equipped with an automatic PFM/PWM mode operation. At light load, the IC operates in the PFM mode to reduce the switching losses. At heavy load, the IC works in PWM.The APW7302B is also equipped with Power-on-reset,soft- start, and whole protections (over-temperature, and current-limit) into a single package.This device, available SOP-8P, provides a very compact system solution external components and PCB area.Simplified Application CircuitPin ConfigurationBS VIN LX GNDSS EN COMP FBAPW7302BSOP-8P(Top View)Exposed PadThe pin 4 must be connected to the pin 9 (Exposed Pad)V INNote: ANPEC lead-free products contain molding compounds/die attach materials and 100% matte tin plate termination finish; which are fully compliant with RoHS. ANPEC lead-free products meet or exceed the lead-free requirements of IPC/JEDEC J -STD-020D for MSL classification at lead-free peak reflow temperature. ANPEC defines “Green” to mean lead-free (RoHS compliant) and halogen free (Br or Cl does not exceed 900ppm by weight in homogeneous material and total of Br and Cl does not exceed 1500ppm by weight).(Note 1)stress ratings only and functional operation of the device at these or any other conditions beyond those indicated under "recom-mended operating conditions" is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliabilityThermal CharacteristicsNote 2: θJA is measured with the component mounted on a high effective thermal conductivity test board in free air.Recommended Operating Conditions (Note 3)Recommended Operating Conditions (Cont.) (Note 3)Note 3: Refer to the typical application circuit.Electrical CharacteristicsUnless otherwise specified, these specifications apply over V IN =12V, V OUT = 3.3V, V EN =3V and T A =25o C.Electrical Characteristics (Cont.)Note 4: Guarantee by design.Unless otherwise specified, these specifications apply over V IN =12V, V OUT = 3.3V, V EN =3V and T A =25o C.Typical Operating CharacteristicsR e f e r e n c e V o l t a g e , V R E F (V )Reference Voltage vs. JunctionTemperatureJunction Temperature, T J (o C)0.90.9050.910.9150.920.9250.930.9350.94-50-25255075100125150Oscillator Frequency vs. JunctionTemperatureJunction Temperature, T J (¢X C)300310320330340350360-50-250255075100125150O s c i l l a t o r F r e q u e n c yV I N I n p u t C u r r e n t , I V I N (m A )VIN Supply Voltage , V IN (V)11.21.41.61.8204812162024VIN Input Current vs. Supply VoltageRefer to the “Typical Application Circuit” The test conditions are V IN =12V, V OUT =3.3V, L1=10µH, C2=22µF, T A = 25o C unless otherwise specified.E f f i c i e n c y (%)Output Current vs. Efficiency2030405060100100.0110Output Current (A)0.110.001708090Operating WaveformsPower OffCH1: V IN , 5V/Div, DC CH2: V OUT , 2V/Div, DC TIME: 5ms/DivCH3: I L1, 2A/Div, DC V INV OUTI L1I OUT =2ATIME: 50µs/DivLoad Transient ResponseCH1: V OUT , 200mV/Div, offset=3.3V CH2: I L1, 1A/Div, DC I OUT =0.5A-2A-0.5A,rise/fall time=10µsI OUTV OUTRefer to the “Typical Application Circuit” The test conditions are V IN =12V, V OUT =3.3V, L1=10µH, C2=22µF, T A = 25o C unless otherwise specified.Power OnCH1: V IN , 5V/Div, DC CH2: V OUT , 2V/Div, DC TIME: 5ms/DivCH3: I L1, 2A/Div, DC I OUT =5AV INV OUTI L1I OUT =2A Load Transient ResponseCH1: V OUT , 200mV/Div, offset=3.3V CH2: I L1, 1A/Div, DC TIME: 50µs/DivI OUTV OUTI OUT =0A -2A -0A ,rise /fall time =10µsSwitching WaveformCH1: V LX , 5V/Div, DC CH2: I L1, 2A/Div, DC TIME: 1µs/DivI OUT =2AV LXShort CircuitCH1: V OUT , 1V/Div, DC CH2: I L1, 2A/Div, DC TIME: 1s/DivV OUT is shorted to GND by a short wireV OUTI L1Operating Waveforms (Cont.)Refer to the “Typical Application Circuit” The test conditions are V IN =12V, V OUT =3.3V, L1=10µH, C2=22µF, T A = 25o C unless otherwise specified.CH1: V OUT , 1V/Div, DC TIME: 50ms/DivCH2: I L1, 2A/Div, DCV OUTI L1I OUT =0~4AOver CurrentSwitching WaveformI LCH1: V LX , 5V/Div, DC TIME: 10µs/DivV LXCH2: I L , 0.5A/Div, DC I OUT =100mALine Transient ResponseV OUTCH1: V IN , 5V/Div, DCTIME: 50µs/DivCH2: V OUT , 50mV/Div, offset=3.3V V IN =12 to 20V, rise/fall time=10µsV INV OUT Operating Waveforms (Cont.)Refer to the “Typical Application Circuit” The test conditions are V IN =12V, V OUT =3.3V, L1=10µH, C2=22µF, T A = 25o C unless otherwise specified.Block DiagramLXVINBSTypical Application CircuitV INRecommended Feedback Compensation ValueFunction DescriptionMain Control LoopThe APW7302B is a constant frequency current modeswitching regulator. During normal operation, the inter-nal N-channel power MOSFET is turned on each cycle when the oscillator sets an internal RS latch and would be turned off when an internal current comparator (ICMP) resets the latch. The peak inductor current at which ICMP resets the RS latch is controlled by the voltage on the COMP pin, which is the output of the error amplifier (EAMP). An external resistive divider connected between VOUT and ground allows the EAMP to receive an output feedback voltage VFBat FB pin. When the load currentincreases, it causes a slight decrease in VFBrelative to the 0.92V reference, which in turn causes the COMP volt-age to increase until the average inductor current matches the new load current.VIN Power-On-Reset (POR) and EN Under-voltage LockoutThe APW7302B keep monitoring the voltage on VIN pin to prevent wrong logic operations which may occur when VIN voltage is not high enough for the internal control circuitry to operate. The VIN POR has a rising threshold of 4.1V (typical) with 0.5V of hysteresis.An external under-voltage lockout (UVLO) is sensed at the EN pin. The EN UVLO has a rising threshold of 2.5V with 0.2V of hysteresis. The EN pin should be connected a resistor divider from VIN to EN.After the VIN and EN voltages exceed their respective voltage thresholds, the IC starts a start-up process and then ramps up the output voltage to the setting of output voltage.Over-Temperature Protection (OTP)The over-temperature circuit limits the junction tempera-ture of the APW7302B. When the junction temperatureexceeds TJ= +160o C, a thermal sensor turns off the power MOSFET, allowing the devices to cool. The thermal sen-sor allows the converter to start a start-up process and regulate the output voltage again after the junction tem-perature cools by 50o C.The OTP is designed with a 50o C hysteresis to lower the average TJduring continuous thermal overload conditions, increasing lifetime of the lC.Current-Limit ProtectionThe APW7302B monitors the output current, flowing through the N-Channel power MOSFET, and limits the IC from damages during overload, short-circuit and over-voltage conditions.Frequency FoldbackThe foldback frequency is controlled by the FB voltage. When the FB pin voltage is under 0.6V, the frequency of the oscillator will be reduced to 110kHz. This lower fre-quency allows the inductor current to safely discharge, thereby preventing current runaway. The oscillator’s fre-quency will switch to its designed rate when the feedback voltage on FB rises above the rising frequency foldback threshold (0.6V, typical) again.Over-Voltage ProtectionThe over-voltage function monitors the output voltage by FB pin. When the FB voltage increase over 120% of the reference voltage, the over-voltage protection compara-tor will force the low-side MOSFET gate driver high. This action actively pulls down the output voltage. As soon as the output voltage is within regulation, the OVP compara-tor is disengaged. The chip will restore its normal operation.Enable / ShutdownDriving EN to ground places the APW7302B in shutdown. When in shutdown, the internal power MOSFET turns off, all internal circuitry shuts down.Application InformationSetting Output VoltageInductor Capacitor Selectionwhere D is the duty cycle of the power MOSFET .For a through hole design, several electrolytic capacitors may be needed. For surface mount designs, solid tanta-lum capacitors can be used, but caution must be exer-cised with regard to the capacitor surge current rating.)A ()D 1(D I I OUT RMS ⋅−×=)V (ESR I V OUT ⋅×∆=∆OUTOSC COUT C F 8IV ××∆=∆The regulated output voltage is determined by:Use small ceramic capacitors for high frequency decoupling and bulk capacitors to supply the surge cur-rent needed each time the N-channel power MOSFET (Q1) turns on. Place the small ceramic capacitors physi-cally close to the VIN and between the VIN and GND.The important parameters for the bulk input capacitor are the voltage rating and the RMS current rating. For reliable operation, select the bulk capacitor with voltage and current ratings above the maximum input voltage and largest RMS current required by the circuit. The capacitor voltage rating should be at least 1.25 times greater than the maximum input voltage and a voltage rating of 1.5times is a conservative guideline. The RMS current (IRMS)of the bulk input capacitor is calculated as the following equation:An output capacitor is required to filter the output and sup-ply the load transient current. The filtering requirements are the function of the switching frequency and the ripple current (DI). The output ripple is the sum of the voltages,having phase shift, across the ESR and the ideal output capacitor. The peak-to-peak voltage of the ESR is calcu-ated as the following equations:)V ()R R 1(92.0VOUT 21⋅+×=To prevent stray pickup, please locate resistors R1 and R2 close to APW7302B.ESRI V LF )D 1(V I V V D ESR OSC OUT INOUT ×∆=−=∆=××The peak- to-peak voltage of the ideal output capacitor iscalculated as the following equations:For the applications using bulk capacitors, the ∆V COUT is much smaller than the V ESR and can be ignored. Therefore,the AC peak-to-peak output voltage(∆V OUT ) is shown below:Output Capacitor SelectionFor the applications using bulk capacitors, the V ESR is much smaller than the ∆V COUT and can be ignored.Therefore, the AC peak-to-peak output voltage(∆V OUT ) is to ∆V COUT .Figure 1. Converter WaveformsI OUTVLXI LI Q1I COUTI OUTV OUT (1) (2) (3) (4) (5)INV OUTApplication Information(Cont.)Output Capacitor Selection (Cont.)The load transient requirements are the function of the slew rate (di/dt) and the magnitude of the transient load urrent. These requirements are generally met with a mix of capacitors and careful layout. High frequency ca-pacitors initially supply the transient and slow the current load rate seen by the bulk capacitors. The bulk filter ca-pacitor values are generally determined by the ESR (Effective Series Resistance) and voltage rating require-ments rather than actual capacitance requirements.High frequency decoupling capacitors should be placed as close to the power pins of the load as physically possible. Be careful not to add inductance in the circuit board wiring that could cancel the usefulness of these low inductance components. An aluminum electrolytic capacitor’s ESR value is related to the case size with lower ESR available in larger case sizes. However, the Equiva-lent Series Inductance (ESL) of these capacitors increases with case size and can reduce the usefulness of the ca-pacitor to high slew-rate transient loading.The operating frequency and inductor selection are inter-related in that higher operating frequencies permit the use of a smaller inductor for the same amount of inductorripple current. However, this is at the expense of efficiency due to an increase in MOSFET gate charge losses. The equation (2) shows that the inductance value has a direct effect on ripple current.Accepting larger values of ripple current allows the use of low inductances, but results in higher output voltage ripple and greater core losses. A reasonable starting point for setting ripple current is ∆I< 0.4 x I OUT (max). Please be no-ticed that the maximum ripple current occurs at the maxi-mum input voltage. The minimum inductance of the in-uctor is calculated by using the following equation:Inductor Value Calculationwhere (6)IN(MAX)IN V V = 1.2V · L · 340000)V -(V · V IN OUT IN OUT ≤(H)V · 408000)V -(V · V L INOUT IN OUT ≥Application Information (Cont.)Thermal ConsiderationLayout ConsiderationIn high power switching regulator, a correct layout is important to ensure proper operation of the regulator. In general, interconnecting impedance should be minimized by using short, wide printed circuit traces. Signal and power grounds are to be kept separating and finally combined using the ground plane construction or single point grounding. Figure 3 illustrates the layout, with bold lines indicating high current paths. Components along the bold lines should be placed close together. Below is a checklist for your layout:1. Begin the layout by placing the power components first.Orient the power circuitry to achieve a clean power flow path. If possible, make all the connections on one side of the PCB with wide, copper filled areas.2. In Figure 3, the loops with same color bold lines con-duct high slew rate current. These interconnecting im-pedances should be minimized by using wide and short printed circuit traces.3. Keep the sensitive small signal nodes (FB, COMP)away from switching nodes (LX or others) on the PCB and it should be placed near the IC as close as possible.Therefore, place the feedback divider and the feedback compensation network close to the IC to avoid switching noise. Connect the ground of feedback divider directly to the GND pin of the IC using a dedicated ground trace.The APW7302B maximum power dissipation depends on the thermal resistance and temperature difference between the die junction and ambient air. The power dis-sipation P D across the device is:P D = (T J - T A ) / θJAwhere (T J -T A ) is the temperature difference between the junction and ambient air. θJA is the thermal resistance between Junction and ambient air.For normal operation, do not exceed the maximum junc-tion temperature rating of T J = 125o C. The calculated power dissipation should less than:P D = (125-25)/50= 2(W)4. Place the decoupling ceramic capacitor C1 near the VIN as close as possible. Use a wide power ground plane to connect the C1, C2, and Schottky diode to provide a low impedance path between the components for large and high slew rate current.Figure 2. Current Path DiagramFigure 3. Recommended Layout DiagramSensitive node (FB, COMP) should be away from switching node(LX) and it should be placed nearthe thermal pad to thedissipation11.52255075100125Ambient Temperature, T A (o C)M a x i m u m P o w e r D i s s i p a t i o n , P D (W )V OUTVPackage InformationSOP-8PoSEE VIEW AVIEW AGAUGE PLANE SEATING PLANENote : 1. Followed from JEDEC MS-012 BA.2. Dimension "D" does not include mold flash, protrusions or gate burrs. Mold flash, protrusion or gate burrs shall not exceed 6 mil per side .3. Dimension "E" does not include inter-lead flash or protrusions. Inter-lead flash and protrusions shall not exceed 10 mil per side.0.0200.0100.0200.0500.0060.063MAX.0.40L 00o C E e h E10.25D c b 0.170.310.0161.278o C0o C8o C 0.501.27 BSC0.510.250.050 BSC0.0100.0120.007MILLIMETERS MIN.S Y M B O L A1A2A 0.001.25SOP-8PMAX.0.151.60MIN.0.0000.049INCHESD1 2.500.0982.000.079E2 3.503.000.1380.1184.805.000.1890.1973.80 4.000.1500.1575.806.200.2280.244(mm)Carrier Tape & Reel DimensionsSECTION B-BSECTION A-ATaping Direction InformationSOP-8PUSER DIRECTION OF FEEDClassification ProfileClassification Reflow ProfilesTable 1. SnPb Eutectic Process – Classification Temperatures (Tc)Table 2. Pb-free Process – Classification Temperatures (Tc)Reliability Test ProgramCustomer ServiceAnpec Electronics Corp.Head Office :No.6, Dusing 1st Road, SBIP,Hsin-Chu, Taiwan, R.O.C.Tel : 886-3-5642000Fax : 886-3-5642050Taipei Branch :2F, No. 11, Lane 218, Sec 2 Jhongsing Rd.,Sindian City, Taipei County 23146, TaiwanTel : 886-2-2910-3838Fax : 886-2-2917-3838。

常用开关电源芯片大全第1章DC-DC电源转换器/基准电压源DC-DC电源转换器1.低噪声电荷泵DC-DC电源转换器AAT3113/AAT31142.低功耗开关型DC-DC电源转换器ADP30003.高效3A开关稳压器AP15014.高效率无电感DC-DC电源转换器FAN56605.小功率极性反转电源转换器ICL76606.高效率DC-DC电源转换控制器IRU30377.高性能降压式DC-DC电源转换器ISL64208.单片降压式开关稳压器L49609.大功率开关稳压器L4970A降压式开关稳压器L4971高效率单片开关稳压器L4978高效率升压/降压式DC-DC电源转换器L5970降压式DC-DC电源转换器LM157214.高效率1A降压单片开关稳压器LM1575/LM2575/LM2575HV降压单片开关稳压器LM2576/LM2576HV16.可调升压开关稳压器LM2577降压开关稳压器LM259618.高效率5A开关稳压器LM267819.升压式DC-DC电源转换器LM2703/LM270420.电流模式升压式电源转换器LM273321.低噪声升压式电源转换器LM275022.小型75V降压式稳压器LM500723.低功耗升/降压式DC-DC电源转换器LT107324.升压式DC-DC电源转换器LT161525.隔离式开关稳压器LT172526.低功耗升压电荷泵LT175127.大电流高频降压式DC-DC电源转换器LT176528.大电流升压转换器LT193529.高效升压式电荷泵LT193730.高压输入降压式电源转换器LT1956升压式电源转换器LT196132.高压升/降压式电源转换器LT343333.单片3A升压式DC-DC电源转换器LT343634.通用升压式DC-DC电源转换器LT346035.高效率低功耗升压式电源转换器LT3464升压式DC-DC电源转换器LT346737.大电流高效率升压式DC-DC电源转换器LT378238.微型低功耗电源转换器LTC1754单片同步降压式稳压器LTC187540.低噪声高效率降压式电荷泵LTC191141.低噪声电荷泵LTC3200/LTC3200-542.无电感的降压式DC-DC电源转换器LTC325143.双输出/低噪声/降压式电荷泵LTC325244.同步整流/升压式DC-DC电源转换器LTC340145.低功耗同步整流升压式DC-DC电源转换器LTC340246.同步整流降压式DC-DC电源转换器LTC340547.双路同步降压式DC-DC电源转换器LTC340748.高效率同步降压式DC-DC电源转换器LTC341649.微型2A升压式DC-DC电源转换器LTC3426两相电流升压式DC-DC电源转换器LTC342851.单电感升/降压式DC-DC电源转换器LTC344052.大电流升/降压式DC-DC电源转换器LTC3442同步升压式DC-DC电源转换器LTC345854.直流同步降压式DC-DC电源转换器LTC370355.双输出降压式同步DC-DC电源转换控制器LTC373656.降压式同步DC-DC电源转换控制器LTC377057.双2相DC-DC电源同步控制器LTC380258.高性能升压式DC-DC电源转换器MAX1513/MAX151459.精简型升压式DC-DC电源转换器MAX1522/MAX1523/MAX152460.高效率40V升压式DC-DC电源转换器MAX1553/MAX155461.高效率升压式LED电压调节器MAX1561/MAX159962.高效率5路输出DC-DC电源转换器MAX156563.双输出升压式DC-DC电源转换器MAX1582/MAX1582Y64.驱动白光LED的升压式DC-DC电源转换器MAX158365.高效率升压式DC-DC电源转换器MAX1642/MAX1643降压式开关稳压器MAX164467.高效率升压式DC-DC电源转换器MAX1674/MAX1675/MAX167668.高效率双输出DC-DC电源转换器MAX167769.低噪声1A降压式DC-DC电源转换器MAX1684/MAX168570.高效率升压式DC-DC电源转换器MAX169871.高效率双输出降压式DC-DC电源转换器MAX171572.小体积升压式DC-DC电源转换器MAX1722/MAX1723/MAX172473.输出电流为50mA的降压式电荷泵MAX173074.升/降压式电荷泵MAX175975.高效率多路输出DC-DC电源转换器MAX1800同步整流降压式稳压型MAX1830/MAX183177.双输出开关式LCD电源控制器MAX187878.电流模式升压式DC-DC电源转换器MAX189679.具有复位功能的升压式DC-DC电源转换器MAX194780.高效率PWM降压式稳压器MAX1992/MAX199381.大电流输出升压式DC-DC电源转换器MAX61882.低功耗升压或降压式DC-DC电源转换器MAX629升压式DC-DC电源转换器MAX668/MAX66984.大电流PWM降压式开关稳压器MAX724/MAX72685.高效率升压式DC-DC电源转换器MAX756/MAX75786.高效率大电流DC-DC电源转换器MAX761/MAX76287.隔离式DC-DC电源转换器MAX8515/MAX8515A88.高性能24V升压式DC-DC电源转换器MAX872789.升/降压式DC-DC电源转换器MC33063A/MC34063A升压/降压/反向DC-DC电源转换器MC33167/MC3416791.低噪声无电感电荷泵MCP1252/MCP125392.高频脉宽调制降压稳压器MIC220393.大功率DC-DC升压电源转换器MIC229594.单片微型高压开关稳压器NCP1030/NCP103195.低功耗升压式DC-DC电源转换器NCP1400A96.高压DC-DC电源转换器NCP140397.单片微功率高频升压式DC-DC电源转换器NCP141098.同步整流PFM步进式DC-DC电源转换器NCP142199.高效率大电流开关电压调整器NCP1442/NCP1443/NCP1444/NCP1445 100.新型双模式开关稳压器NCP1501101.高效率大电流输出DC-DC电源转换器NCP1550102.同步降压式DC-DC电源转换器NCP1570103.高效率升压式DC-DC电源转换器NCP5008/NCP5009104.大电流高速稳压器RT9173/RT9173A105.高效率升压式DC-DC电源转换器RT9262/RT9262A106.升压式DC-DC电源转换器SP6644/SP6645107.低功耗升压式DC-DC电源转换器SP6691108.新型高效率DC-DC电源转换器TPS54350109.无电感降压式电荷泵TPS6050x110.高效率升压式电源转换器TPS6101x恒流白色LED驱动器TPS61042112.具有LDO输出的升压式DC-DC电源转换器TPS6112x113.低噪声同步降压式DC-DC电源转换器TPS6200x114.三路高效率大功率DC-DC电源转换器TPS75003115.高效率DC-DC电源转换器UCC39421/UCC39422控制升压式DC-DC电源转换器XC6371117.白光LED驱动专用DC-DC电源转换器XC9116同步整流降压式DC-DC电源转换器XC9215/XC9216/XC9217 119.稳压输出电荷泵XC9801/XC9802120.高效率升压式电源转换器ZXLB1600线性/低压差稳压器121.具有可关断功能的多端稳压器BAXXX122.高压线性稳压器HIP5600123.多路输出稳压器KA7630/KA7631124.三端低压差稳压器LM2937125.可调输出低压差稳压器LM2991126.三端可调稳压器LM117/LM317127.低压降CMOS500mA线性稳压器LP38691/LP38693 128.输入电压从12V到450V的可调线性稳压器LR8非常低压降稳压器（VLDO）LTC3025130.大电流低压差线性稳压器LX8610负输出低压差线性稳压器MAX1735低压差线性稳压器MAX8875133.带开关控制的低压差稳压器MC33375134.带有线性调节器的稳压器MC33998低压差固定及可调正稳压器NCP1117136.低静态电流低压差稳压器NCP562/NCP563137.具有使能控制功能的多端稳压器PQxx138.五端可调稳压器SI-3025B/SI-3157B低压差线性稳压器SPX2975140.五端线性稳压器STR20xx141.五端线性稳压器STR90xx142.具有复位信号输出的双路输出稳压器TDA8133143.具有复位信号输出的双路输出稳压器TDA8138/TDA8138A 144.带线性稳压器的升压式电源转换器TPS6110x145.低功耗50mA低压降线性稳压器TPS760xx146.高输入电压低压差线性稳压器XC6202147.高速低压差线性稳压器XC6204148.高速低压差线性稳压器XC6209F149.双路高速低压差线性稳压器XC6401基准电压源150.新型XFET基准电压源ADR290/ADR291/ADR292/ADR293 151.低功耗低压差大输出电流基准电压源MAX610x152.低功耗基准电压源MAX6120精密基准电压源MC1403基准电压源MCP1525/MCP1541155.低功耗精密低压降基准电压源REF30xx/REF31xx156.精密基准电压源TL431/KA431/TLV431A第2章AC-DC转换器及控制器1.厚膜开关电源控制器DP104C2.厚膜开关电源控制器DP308P系列高电压功率转换控制器DPA423/DPA424/DPA425/DPA4264.电流型开关电源控制器FA13842/FA13843/FA13844/FA138455.开关电源控制器FA5310/FA5311开关电源控制器FAN75567.绿色环保的PWM开关电源控制器FAN7601型开关电源控制器FS6M07652R9.开关电源功率转换器FS6Sxx10.降压型单片AC-DC转换器HV-2405E11.新型反激准谐振变换控制器ICE1QS01电源功率转换器KA1M088013.开关电源功率转换器KA2S0680/KA2S088014.电流型开关电源控制器KA38xx型开关电源功率转换器KA5H0165R型开关电源功率转换器KA5Qxx型开关电源功率转换器KA5Sxx18.电流型高速PWM控制器L499019.具有待机功能的PWM初级控制器L599120.低功耗离线式开关电源控制器L6590SWITCH TN系列电源功率转换器LNK304/LNK305/LNK306SWITCH系列电源功率转换器LNK500/LNK501/LNK52023.离线式开关电源控制器M51995A电源控制器M62281P/M62281FP25.高频率电流模式PWM控制器MAX5021/MAX502226.新型PWM开关电源控制器MC4460427.电流模式开关电源控制器MC4460528.低功耗开关电源控制器MC4460829.具有PFC功能的PWM电源控制器ML482430.液晶显示器背光灯电源控制器ML487631.离线式电流模式控制器NCP120032.电流模式脉宽调制控制器NCP120533.准谐振式PWM控制器NCP120734.低成本离线式开关电源控制电路NCP121535.低待机能耗开关电源PWM控制器NCP1230系列自动电压切换控制开关STR8xxxx37.大功率厚膜开关电源功率转换器STR-F665438.大功率厚膜开关电源功率转换器STR-G865639.开关电源功率转换器STR-M6511/STR-M652940.离线式开关电源功率转换器STR-S5703/STR-S5707/STR-S570841.离线式开关电源功率转换器STR-S6401/STR-S6401F/STR-S6411/STR-S6411F 442.开关电源功率转换器STR-S651343.离线式开关电源功率转换器TC33369～TC3337444.高性能PFC与PWM组合控制集成电路TDA16846/TDA1684745.新型开关电源控制器TDA1685046.“绿色”电源控制器TEA150447.第二代“绿色”电源控制器TEA150748.新型低功耗“绿色”电源控制器TEA153349.开关电源控制器TL494/KA7500/MB3759SwitchⅠ系列功率转换器TNY253、TNY254、TNY255 SwitchⅡ系列功率转换器TNY264P～TNY268G Switch（Ⅱ）系列离线式功率转换器TOP209～TOP227 Switch-FX系列功率转换器TOP232/TOP233/TOP234 Switch-GX系列功率转换器TOP242～TOP25055.开关电源控制器UCX84X56.离线式开关电源功率转换器VIPer12AS/VIPer12ADIP57.新一代高度集成离线式开关电源功率转换器VIPer53 第3章功率因数校正控制/节能灯电源控制器1.电子镇流器专用驱动电路BL83012.零电压开关功率因数控制器FAN48223.功率因数校正控制器FAN75274.高电压型EL背光驱动器HV826场致发光背光驱动器IMP525/IMP5606.高电压型EL背光驱动器/反相器IMP8037.电子镇流器自振荡半桥驱动器IR21568.单片荧光灯镇流器IR21579.调光电子镇流器自振荡半桥驱动器IR215910.卤素灯电子变压器智能控制电路IR216111.具有功率因数校正电路的镇流器电路IR216612.单片荧光灯镇流器IR216713.自适应电子镇流器控制器IR252014.电子镇流器专用控制器KA754115.功率因数校正控制器L656116.过渡模式功率因数校正控制器L656217.集成背景光控制器MAX8709/MAX8709A18.功率因数校正控制器MC33262/MC3426219.固定频率电流模式功率因数校正控制器NCP1653场致发光灯高压驱动器SP440321.功率因数校正控制器TDA4862/TDA486322.有源功率因数校正控制器UC385423.高频自振荡节能灯驱动器电路VK05CFL24.大功率高频自振荡节能灯驱动器电路VK06TL第4章充电控制器1.多功能锂电池线性充电控制器AAT36802.可编程快速电池充电控制器BQ20003.可进行充电速率补偿的锂电池充电管理器BQ20574.锂电池充电管理电路BQ2400x5.单片锂电池线性充电控制器BQ2401x接口单节锂电池充电控制器BQ2402x同步开关模式锂电池充电控制器BQ241008.集成PWM开关控制器的快速充电管理器BQ29549.具有电池电量计量功能的充电控制器DS277010.锂电池充电控制器FAN7563/FAN7564线性锂/锂聚合物电池充电控制器ISL629212.锂电池充电控制器LA5621M/LA5621V通用充电控制器LT1571恒流/恒压电池充电控制器LT176915.线性锂电池充电控制器LTC173216.带热调节功能的1A线性锂电池充电控制器LTC173317.线性锂电池充电控制器LTC173418.新型开关电源充电控制器LTC198019.开关模式锂电池充电控制器LTC4002锂电池充电器LTC400621.多用途恒压/恒流充电控制器LTC4008锂离子/锂聚合物电池充电控制器LTC405223.可由USB端口供电的锂电池充电控制器LTC405324.小型150mA锂电池充电控制器LTC405425.线性锂电池充电控制器LTC405826.单节锂电池线性充电控制器LTC405927.独立线性锂电池充电控制器LTC406128.镍镉/镍氢电池充电控制器M62256FP29.大电流锂/镍镉/镍氢电池充电控制器MAX150130.锂电池线性充电控制器MAX150731.双输入单节锂电池充电控制器MAX1551/MAX155532.单节锂电池充电控制器MAX167933.小体积锂电池充电控制器MAX1736接口单节锂电池充电控制器MAX181135.多节锂电池充电控制器MAX187336.双路输入锂电池充电控制器MAX187437.单节锂电池线性充电控制器MAX189838.低成本/多种电池充电控制器MAX190839.开关模式单节锂电池充电控制器MAX1925/MAX192640.快速镍镉/镍氢充电控制器MAX2003A/MAX200341.可编程快速充电控制器MAX712/MAX71342.开关式锂电池充电控制器MAX74543.多功能低成本充电控制器MAX846A44.具有温度调节功能的单节锂电池充电控制器MAX8600/MAX860145.锂电池充电控制器MCP73826/MCP73827/MCP7382846.高精度恒压/恒流充电器控制器MCP73841/MCP73842/MCP73843/MCP73844 647.锂电池充电控制器MCP73861/MCP7386248.单节锂电池充电控制器MIC7905049.单节锂电池充电控制器NCP180050.高精度线性锂电池充电控制器VM7205。

V V L1TLV62569PProduct Folder Order Now Technical Documents Tools &SoftwareSupport &CommunityTLV62569,TLV62569PZHCSFR4C –DECEMBER 2016–REVISED OCTOBER 2017TLV62569采用SOT 封装的2A 高效同步降压转换器1特性•效率高达95%•低R DS(ON)，可在100m Ω和60m Ω之间切换•输入电压范围：2.5V 至5.5V •可调输出电压：0.6V 至V IN •针对轻载效率的省电模式•针对最低压降的100%占空比•35µA 静态工作电流• 1.5MHz 典型开关频率•电源正常输出•过流保护•内部软启动•热关断保护•采用小外形尺寸晶体管(SOT)封装•与TLV62568引脚兼容•使用TLV62569并借助WEBENCH ®Power Designer 创建定制设计方案2应用•通用负载点(POL)电源•机顶盒•网络视频摄像头•无线路由器•硬盘3说明TLV62569器件是一款同步降压DC-DC 转换器，专门针对高效和紧凑型解决方案进行了优化。

该器件集成的开关能够提供高达2A 的输出电流。

在中等负载或重载条件下，该器件运行在脉宽调制(PWM)模式下，开关频率为1.5MHz 。

在轻载情况下，该器件自动进入节能模式(PSM)，从而在整个负载电流范围内保持高效率。

关断时，流耗减少至2μA 以下。

TLV62569的输出电压可通过一个外部电阻分压器进行调节。

内部软启动电路可限制启动期间的浪涌电流。

此外，还内置了诸如输出过流保护、热关断保护和电源正常输出等其他特性。

该器件提供SOT23和SOT563两种封装。

器件信息(1)器件型号封装封装尺寸（标称值）TLV62569DBV SOT23(5) 2.90mm x 2.80mm TLV62569PDDC SOT23(6)TLV62569DRL SOT563(6) 1.60mm x 1.60mmTLV62569PDRLSOT563(6)(1)要了解所有可用封装，请参阅数据表末尾的可订购产品附录。

180KHz 40V 12A 开关电流降压型DC-DC转换器XL4016特点⏹推荐操作电压范围8V~36V ⏹输出电压从1.25V到32V可调⏹最大占空比100%⏹最小压降0.3V⏹固定180KHz开关频率⏹最大12A开关电流⏹内置功率MOS⏹效率高达96%⏹出色的线性与负载调整率⏹内置热关断功能⏹内置限流功能⏹内置输出短路保护功能⏹TO220-5L封装应用⏹LCD电视与显示屏⏹便携式仪器电源⏹通讯设备供电描述XL4016是一款高效降压型DC-DC转换器，固定180KHz开关频率, 可以提供最高12A输出电流能力，具有低纹波，出色的线性与负载调整率特点。

XL4016内置固定频率振荡器与频率补偿电路，简化了电路设计。

PWM控制环路可以调节占空比从0~100%之间线性变化。

内置输出过电流保护功能。

当输出短路时，开关频率从180KHz降至48KHz。

内置补偿模块可以减少外围元器件数量。

图1.XL4016封装180KHz 40V 12A 开关电流降压型DC-DC 转换器 XL4016引脚配置12345VIN SW FB GNDVC TO220-5LMetal Tab SW图2. XL4016引脚配置表1.引脚说明引脚号 引脚名称 描述1 GND 接地引脚。

2 FB 反馈引脚，通过外部电阻分压网络，检测输出电压进行调整，参考电压为1.25V 。

3 SW 功率开关输出引脚，SW 是输出功率的开关节点。

4VC内部电压调节器旁路电容引脚，需要在VIN 与VC 引脚之间连接1个1uF 电容。

5 VIN电源输入引脚，支持DC8V~36V 宽范围电压操作，需要在VIN 与GND 之间并联电解电容以消除噪声。

180KHz 40V 12A 开关电流降压型DC-DC 转换器 XL4016方框图EAGND FB3.3V1.25VEA COMPOscillator180KHz/48KHz3.3V Regulator1.25V ReferenceStart Up LatchCOMP2COMP1DriverThermal ShutdownVINVC SW220mV 200mV20m ΩCurrent LimitPower PMOS1:100020K Ω3.3nFOSP图3. XL4016方框图典型应用XL4016CIN470uF/50VCOUT1000uF/25VR210K R13.3KD1MBR2045C1105C21055312VIN4VOUT=1.25*(1+R2/R1)IOUT=0~12AVIN VCSWGNDFBCC 105CFF 33nFVOUTVIN=8V~20V, VOUT=5V/9A; VIN=20V~36V, VOUT=5V/12A 图4. XL4016系统参数测量电路（VIN=8~36V, VOUT=5V/12A ）180KHz 40V 12A开关电流降压型DC-DC转换器XL4016订购信息产品型号打印名称封装方式包装类型XL4016E1 XL4016E1 TO220-5L 50只每管/ 1000只每盒XLSEMI无铅产品，产品型号带有“E1”后缀的符合RoHS标准。

DS9722-00 August 2011Note :Richtek products are :` RoHS compliant and compatible with the current require-ments of IPC/JEDEC J-STD-020.` Suitable for use in SnPb or Pb-free soldering processes.Ordering InformationPin Configurations(TOP VIEW)WDFN-6L 2x2SOT-23-5145m Ω, 1.5A Power Switch with Programmable Current LimitGeneral DescriptionThe RT9722 is a cost effective, low voltage, single P-MOSFET high side power switch IC. Typical 145m Ωswitch on resistance and 10μA quiescent current are realized in this IC. In order to fit different application, a SET pin is offered for current limit point setting, a resistor from SET to Ground sets the current limit for this switch.In addition, the RT9722 integrates a thermal shutdown circuit and under voltage lockout circuit for overall protection, and a FLAG output with delay is available to indicate fault conditions to the local controller.The RT9722 is an ideal solution for high side power load switch and can support flexible applications since it is available in various package such as WDFN-6L 2x2,SOT-23-5 and SOT-23-6.Featuresz Programmable Current Limit : 0.2A to 1.5A z Low Quiescent Current : 10μA z Low Shutdown Current : 0.1μA z 145m Ω Switch On Resistancez Operating Voltage Range : 2.4V to 5.5V z Under Voltage Lockoutz Thermal Shutdown ProtectionzRoHS Compliant and Halogen FreeApplicationsz Handheld Devices z Hot Swap Suppliesz Notebooksz Peripheral PortszPersonal Communication DevicesEN/ENEN/ENFLG SETVIN NC VOUTFLGEN/EN SOT-23-6RT9722A : Active HighB : Active LowTypical Application CircuitFigure 1. Typical Application Circuit for SOT-23-5Package Figure 2. Typical Application Circuit for SOT-23-6 andWDFN-6L 2x2 PackageMarking Information1H= : Product Code DNN : Date CodeDQ= : Product Code DNN : Date CodeH0 : Product Code W : Date CodeDT= : Product Code DNN : Date CodeH1 : Product Code W : Date Code1S= : Product Code DNN : Date CodeRT9722AGB RT9722AGQW RT9722BGB RT9722BGQWDS9722-00 August 2011Function Block DiagramTo be continuedAbsolute Maximum Ratings (Note 1)z Supply Input Voltage, V IN ------------------------------------------------------------------------------------------------6Vz EN Voltage ------------------------------------------------------------------------------------------------------------------−0.3V to 6V z FLAG, SET Voltage -------------------------------------------------------------------------------------------------------6V zPower Dissipation, P D @ T A = 25°CSOT-23-5/SOT-23-6-------------------------------------------------------------------------------------------------------0.4W WDFN-6L 2x2--------------------------------------------------------------------------------------------------------------0.606W zPackage Thermal Resistance (Note 2)SOT-23-5/SOT-23-6-------------------------------------------------------------------------------------------------------250°C/W WDFN-6L 2x2, θJA ---------------------------------------------------------------------------------------------------------165°C/W z Lead Temperature (Soldering, 10 sec.)-------------------------------------------------------------------------------260°C z Junction T emperature -----------------------------------------------------------------------------------------------------150°Cz Storage T emperature Range --------------------------------------------------------------------------------------------−65°C to 150°C zESD Susceptibility (Note 3)HBM --------------------------------------------------------------------------------------------------------------------------2kV MM ----------------------------------------------------------------------------------------------------------------------------200VRecommended Operating Conditions (Note 4)z Supply Input Voltage, V IN ------------------------------------------------------------------------------------------------2.4V to 5.5V z EN Voltage ------------------------------------------------------------------------------------------------------------------0V to 5.5Vz Junction T emperature Range --------------------------------------------------------------------------------------------−40°C to 125°C zAmbient T emperature Range --------------------------------------------------------------------------------------------−40°C to 85°C Electrical Characteristics(V IN = 5V, C IN = 1μF, C OUT = 0.47μF, T A= 25°C, unless otherwise specified)DS9722-00 August 2011Note 1. Stresses listed as the above “Absolute Maximum Ratings ” may cause permanent damage to the device. These are forstress ratings. Functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may remain possibility to affect device reliability.Note 2. θJA is measured in the natural convection at T A = 25°C on a low effective thermal conductivity single layer test board ofJEDEC 51-3 thermal measurement standard.Note 3. Devices are ESD sensitive. Handling precaution is recommended.Note 4. The device is not guaranteed to function outside its operating conditions.Typical Operating CharacteristicsShutdown Current vs. Temperature0.20.40.60.81-50-25255075100125Temperature (°C)S h u t d o w n C u r r e n t (μA )Output Current vs. Output Voltage0100200300400500600012345Output Voltage (V)O u t p u t C u r r e n t (m A)R DS(ON) vs. Input Voltage2.533.544.555.5Input Voltage (V)R D S (O N ) (m Ω)Supply Current vs. Temperature02468101214161820-50-25255075100125Temperature (°C)S u p p l y C u r r e n t (μA )Supply Current vs. Input Voltage2.533.544.555.5Input Voltage (V)S u p p l y C u r r e n t (μA )R DS(ON) vs. Temperature50100150200250300-50-250255075100125Temperature (°C)R D S (O N ) (m Ω)DS9722-00 August 2011UVLO Threshold Voltage vs. Temperature0.00.20.40.60.81.01.21.41.61.82.02.22.42.6-50-25255075100125Temperature (°C)U V L O T h r e s h o l d V o l t a g e (V )Current Limit vs. R SET02004006008001000120014001600010203040506070R SET (k Ω)C u r r e n tL i m i t (m A )Flag Delay Time vs. Input Voltage2.533.544.555.5Input Voltage (V)F l a g D e l a y T i m e (m s )Turn-On Time vs. Temperature051015202530-50-25255075100125Temperature (°C)T u r n -O n T i m e (μs )EN Threshold Voltage vs. Input Voltage2.533.544.555.5Input Voltage (V)E N T h r e s h o l d V o l t a g e (V )Turn-Off Time vs. Temperature024681012-50-25255075100125Temperature (°C)T u r n -O f f T i m e (μs )Short Circuit ProtectionTime (25ms/Div)I OUT(500mA/Div)V OUT (1V/Div)V IN (5V/Div)V IN = 5V, R SET = 6.8k Ω, R LOAD = 0Ω, C OUT = 0.47μFFlag (5V/Div)Current Limit with Thermal Shutdown Time (250ms/Div)I OUT(500mA/Div)V OUT (5V/Div)V IN (5V/Div)V IN = 5V, R SET = 16k Ω, R LOAD = 1Ω, C OUT = 0.47μFFlag (5V/Div)Power On from ENTime (25μs/Div)I OUT(200mA/Div)V OUT (2V/Div)V EN (5V/Div)V IN = 5V, R SET = 6.8k Ω, R LOAD = 10Ω, C OUT = 0.47μFPower Off from ENTime (10μs/Div)I OUT(200mA/Div)V OUT (2V/Div)V EN (5V/Div)V IN = 5V, R SET = 6.8k Ω, R LOAD = 10Ω, C OUT = 0.47μFDS9722-00 August 2011Application InformationThe RT9722 is a high-side power switch with programmable current limit function. The RT9722 provides active-high (RT9722A) and active-low (RT9722B) enable input and full protection functions make it optimized to replace complex discrete on/off control circuitry.Current Limit SettingThe current limit value I LIM , can be set by an external resistor between SET and GND. Figure 3 shows the typical current limit value under various setting resistance, R SET .Figure 3. Current Limit vs. R SET ResistanceThe accuracy of current limit set point may vary withoperating temperature and supply voltage, see “Typical Operating Characteristics ” graph for further details.A few standard resistor values of the R SET and its typical current limit set point with ±25% tolerance are listed in Table 1.Input and OutputV IN (input) is the power source connected to the internal circuitry and the source of the MOSFET . V OUT (output) is the drain of the MOSFET. In a typical application, current flows through the switch from V IN to V OUT toward the load.If V OUT is greater than V IN , current will flow from V OUT to V IN since the MOSFET is bidirectional when on. The RT9722 is designed to control current flowing from V IN to V OUT . If a voltage applied to V OUT is greater than the voltage on V IN , large currents may flow and cause damage to the device.Chip Enable InputThe switch will be disabled when the EN/EN pin is in a logic low/high condition. During this condition, the internal circuitry and MOSFET are turned off, reducing the supply current to 0.1μA typically. The maximum guaranteed voltage for a logic low at the EN pin is 0.6V. A minimum guaranteed voltage of 1.4V at the EN pin will turn on the RT9722 again. Floating the input may cause unpredictable operation. EN should not be allowed to go negative with respect to GND. The EN pin can be directly tied to V IN to keep the part on.Soft-Start for Hot Plug-In ApplicationsIn order to eliminate the upstream voltage droop caused by the large inrush current during hot-plug events, the “soft-start ” feature effectively isolates the power source from extremely large capacitive loads.Fault FlagThe RT9722 provides a FLG signal pin which is an N-Channel open drain MOSFET output. This open drain output goes low when current limit V OUT < V IN − 1V, or the die temperature exceeds 150°Current Limit vs. R SET02004006008001000120014001600010203040506070R SET (kΩ)C u r r e n t L i m i t (m A )(k Ω)pin requires a pull-up resistor, this resistor should be large in value to reduce energy drain. A 100k pull-up resistor works well for most applications. In the case of an over-current condition, FLG will be asserted only after the flag response delay time, t D, has elapsed. This ensures that FLG is asserted only upon valid over-current conditions and that erroneous error reporting is eliminated.For example, false over-current conditions may occur during hot-plug events when a highly large capacitive load is connected and causes a high transient inrush current that exceeds the current limit threshold. The FLG response delay time t D is typically 12ms at V IN = 5V.Under-Voltage LockoutUnder-voltage lockout (UVLO) prevents the MOSFET switch from turning on until input voltage exceeds approximately 2V. Under-voltage detection functions only when the chip enable input is enabled.Thermal ShutdownThermal shutdown is employed to protect the device from damage if the die temperature exceeds approximately 150°C. If enabled, the switch automatically restarts when the die temperature falls 20°C (typ.). The output will continue to cycle on and off until the device is disabled or the fault is removed.Short Circuit ProtectionThe current limit circuitry prevents damage to the MOSFET switch and external load. When a heavy load or short circuit is applied to an enabled switch, a large transient current may flow until the current limit circuitry responds. Once this current limit threshold is exceeded, the device enters constant current mode until the thermal shutdown occurred or the fault is removed.Supply Filter/Bypass CapacitorA 1μF low-ESR ceramic capacitor from V IN to GND (the amount of the capacitance may be increased without limit), located at the device is strongly recommended to prevent the input voltage drooping during hot-plug events. However, higher capacitor values will further reduce the voltage droop on the input. Furthermore, without the bypass capacitor, an output short may cause sufficient ringing on the input (from source lead inductance) to destroy the internal control circuitry. An important note to be award of is the parasitic inductance of PCB traces can cause over-voltage transients if the PCB trace has even a few tens of nH of inductance. The input transient must not exceed 6.0V of the absolute maximum supply voltage even for a short duration.Power DissipationThe device's junction temperature depends on several factors such as the load, PCB layout, ambient temperature and package type. The maximum output current must be derated at higher ambient temperature to ensure the junction temperature does not exceed operating junction temperature 125°C. With all possible conditions, the junction temperature must be within the range specified under operating conditions. Power dissipation can be calculated based on the output current and the R DS(ON) of switch as below.P D = R DS(ON) x I OUT2The application may limit the amount of output current based on the total power dissipation and the ambient temperature.Thermal ConsiderationsThe maximum power dissipation depends on the thermal resistance of IC package, PCB layout, the rate of surroundings airflow and temperature difference between junction to ambient. The maximum power dissipation can be calculated by following formula :P D(MAX) = (T J(MAX)− T A) / θJAWhere T J(MAX) is the maximum operation junction temperature, T A is the ambient temperature and the θJA is the junction to ambient thermal resistance.For recommended operating conditions specification of RT9722, the maximum operating junction temperature is 125°C. The junction to ambient thermal resistance θJA for SOT-23-5/SOT-23-6 package is 250°C/W and WDFN-6L 2x2 package is 165°C/W on the standard JEDEC 51-3 single-layer thermal test board. The maximum power dissipation at T A = 25°C can be calculated by following formula :P D(MAX) = (125°C − 25°C) / (250°C/W) = 0.4W for SOT-23-5/SOT-23-6 packageDS9722-00 August 2011Figure 4. RT9722 Maximum Power Dissipation DeratingCurve0.000.100.200.300.400.500.600.700255075100125Ambient Temperature (°C)P o w e r D i s s i p a t i o n (W )Layout ConsiderationFor the best performance of the RT9722, careful PCB layout is necessary. The following guidelines must be considered:`Keep all input and output traces as short and wide as possible.`Locate the bypass capacitors as close as possible to the input and output pin of the RT9722.`Avoid vias as much as possible. If vias are necessary,make them as large as feasible.`Place a ground plane under all circuitry to lower both resistance and inductance and improve DC and transient performance (Use a separate ground and power plane if possible).Figure 5. PCB Layout GuideP D(MAX) = (125°C − 25°C) / (165°C/W) = 0.606W for WDFN-6L 2x2 packageThe maximum power dissipation depends on operating ambient temperature for fixed T J(MAX) and thermal resistance θJA . For the RT9722 Figure 4 shows the maximum power dissipation allowed under various ambient temperatures.possible to the IC.A1HLSOT-23-5 Surface Mount PackageOutline DimensionDS9722-00 August 2011A1HSOT-23-6 Surface Mount PackageRichtek Technology CorporationHeadquarter5F, No. 20, Taiyuen Street, Chupei City Hsinchu, Taiwan, R.O.C.Tel: (8863)5526789 Fax: (8863)5526611Information that is provided by Richtek Technology Corporation is believed to be accurate and reliable. Richtek reserves the right to make any change in circuit design, specification or other related things if necessary without notice at any time. No third party intellectual property infringement of the applications should be guaranteed by users when integrating Richtek products into any application. No legal responsibility for any said applications is assumed by Richtek.Richtek Technology CorporationTaipei Office (Marketing)5F, No. 95, Minchiuan Road, Hsintien City Taipei County, Taiwan, R.O.C.Tel: (8862)86672399 Fax: (8862)86672377Email:*********************W-Type 6L DFN 2x2 Package。