Dxx

各种图像格式的分辨率CIFDxxVGA经常在很多场合看到各种不同图像格式的分辨率,下⾯整理⼀下.在电视或者监控⾏业, 常常⽤到CIF。

CIF是常⽤的标准化图像格式（Common Intermediate Format）。

在H.323协议簇中，规定了视频采集设备的标准采集分辨率。

CIF = 352×288像素CIF格式具有如下特性：(1) 电视图像的空间分辨率为家⽤录像系统(Video Home System，VHS)的分辨率，即352×288。

(2) 使⽤⾮隔⾏扫描(non-interlaced scan)。

(3) 使⽤NTSC帧速率，电视图像的最⼤帧速率为30 000/1001≈29.97幅/秒。

(4) 使⽤1/2的PAL⽔平分辨率，即288线。

(5) 对亮度和两个⾊差信号(Y、Cb和Cr)分量分别进⾏编码，它们的取值范围同ITU-R BT.601。

即⿊⾊=16，⽩⾊=235，⾊差的最⼤值等于240，最⼩值等于16。

QCIF全称Quarter common intermediate format。

QCIF是常⽤的标准化图像格式。

在H.323协议簇中，规定了视频采集设备的标准采集分辨率。

QCIF = 176×144像素。

下⾯为5种CIF 图像格式的参数说明。

参数次序为“图象格式亮度取样的象素个数(dx) 亮度取样的⾏数 (dy) ⾊度取样的象素个数(dx/2) ⾊度取样的⾏数(dy/2)”。

sub-QCIF 128×96 64 48QCIF 176×144 88 72CIF 352×288 176 1444CIF(D1) 704×576 352 28816CIF 1408×1152 704 576⽬前监控⾏业中主要使⽤Qcif（176×144）、CIF（352×288）、HALF D1(704×288）、D1（704×576）等⼏种分辨率，CIF 录像分辨率是主流分辨率，绝⼤部分产品都采⽤CIF分辨率。

按键 按键 同时按 和 键 按或键
工程师模式 执行设定数据锁 执行自整定
8
5. 2.修改设定值
本仪表中所有参数的设置都是通过对原有值进行增减来实现的 对于设定值 SV 也有一样 通过
前面板上的
键就可以设置
例如:要将设定值改为 200 , 首先要看仪表是否处于 PV/SV 显示设定模式(常规模式) 如不是可
注:在下列 4 种模式下, 如果仪表按键在 1 分钟内没有被按动, 将自动回到常规模式 这 4 种模式为:*
操作设定模式 *工程师模式 *工程师设定模式和配置模式 如果在参数设定过程中, 仪表回到常规模式 PV/SV, 则正设定的参数值不会被存入
上电
输入类型/输入范围显示
显示自动改变
持续按住 2 秒钟
常规模式
按和键
按键
按键
输入类型设置 用于改变传感器类型 范围见输入类型表 出厂设置 0
量程上限设置 用于设置测量值上限 范围从量程下限到 9999 出厂设置 999.9
量程下限设置 用于设置测量值下限 范围从-1999 到量程上限 出厂设置 -199.9
小数点位置 0 无小数 1 一位小数 2 两位小数 3 三位小数 出厂设置 1
键修改 14 CT1 指示灯,此时仪表第二行显示值为 CT1 的电流值
15 CT2 指示灯,此时仪表第二行显示值为 CT2 的电流值7 Nhomakorabea 5. 操作
5.1 各种模式的进入方法 本仪表共有以下 6 种模式
z PV/SV 显示设定模式(常规模式):显示出 PV 和 SV, 并且可以修改 SV z 操作模式:用于改变仪表的手动/自动状态,及显示 CT 的电流值等 z 操作设定模式:用于设定报警值等 z 工程师模式:用于启动自整定和保护锁 z 工程师设定模式:用于设定如 PID 等工作参数 z 配置模式:用于设置输入输出类型 仪表控制功能参数 (这些参数通常是不能修改的)

浅谈函数点x处可微及其与可导的关系摘要：可微与可导及其关系是微积分学中的一个入门级重点，更是一个难点。

以增量、高阶无穷小为突破口，分析了可微与微分的定义，通过严格证明论述其与可导的关系，并举例说明微分的基本求法。

关键词：增量高阶的无穷小可微可导1 引言导数与微分是学习微积分学中的钥匙。

经常给人不好理解的印象，但如果以增量、高阶无穷小为突破口，去看微分的定义，并严格证明论述其与可导的关系，在加上一些简单微分的基本求，达到条理清晰、深入浅出的效果。

2 增量△y是否能写成A△x+O（△x）的意义2.1增量△y是否能写成A△x+O（△x）设函数y=f（x）在点x的某个邻域=3x2·△x+（3x·（△x）2+（△x）3）内有定义，则y=f（x）在点x的增量△y=f（x+△x）-f（x）。

如果我们对△y=f（x+△x）-f（x）的结果进行整理，就会发现，对于有些函数y=f（x）及点x来说△y=f（x+△x）-f（x）的结果可以整理成△y=f（x+△x）-f（x）=A△x+O（△x），这里A与△x无关，O（△x）是较△x高阶的无穷小，但是对于有些函数y=f（x）及点x来说△y=f（x+△x）-f（x）的结果无法整理成上述形式。

例如：y=x2在点x0的增量就可以写成上述形式，△y=（x0+△x）2-x02=2x0·△x+（△x）2，这里2x0与△x无关，（△x）2是较△x高阶的无穷小。

但是，y=在点x=0的增量就无法写成上述形式，△y=f（0+△x）-f（0）=-0= 。

2.2增量△y是否能写成A△x+O（△x）的意义为什么要研究函数y=f（x）在点x的增量△y是否能写成A△x+O（△x）呢？可以看到，如果函数y=f（x）在点x的增量△y能写成△y=A△x+O（△x），那么当△x的值很小时，O（△x）值就会比A△x的值小的多，可以忽略不记，即当△x的值很小时△y≈A△x，这时我们只要知道A的值就可以很方便地计算出函数y=f（x）在点x的增量△y的近似值。

UNISONIC TECHNOLOGIES CO.,78DxxA Linear Integrated Circuit3-TERMINALS 1A POSITIVE VOLTAGE REGULATORDESCRIPTIONThe UTC 78DXXA family is monolithic fixed voltage regulator integrated circuit. They are suitable for applications that required supply current up to 1 A.FEATURES* Peak output current up to 1A.* Fixed output voltage of 3.3V, 4.7V, 5V, 6V, 7V, 8V, 9V, 10V,12V, 15V, 18V and 24V available.* Thermal overload shutdown protection.* Short circuit current limiting.* Output transistor SOA protection.*Pb-free plating product number: 78DxxAL PIN CONFIGURATIONPIN NO.PIN NAME1 Input2 Ground3 OutputORDERING INFORMATIONOrdering NumberNormal Lead Free PlatingPackage Packing 78DxxA-TM3-T 78DxxAL-TM3-T TO-251 Tube 78DxxA-TN3-R 78DxxAL-TN3-R TO-252 TapeReel 78DxxA-TN3-T 78DxxAL-TN3-T TO-252 Tube Note: xx: Output Voltage, refer to below table.OUTPUT VOLTAGE INFORMATIONOutput Voltage Code3.3V 334.7V 475V 056V 067V 078V 089V 0910V 1012V 1215V 1518V 1824V 24BLOCK DIAGRAMINPUTZ1APPLICATION CIRCUITNote:Bypass capacitors are recommended for optimum stability and transient response and should be locatedas close as possible to the regulators.ABSOLUATE MAXIUM RATINGS (Ta = 25℃,unless otherwise specified)PARAMETER SYMBOL RATINGS UNITV OUT =3.3~18V 35Input Voltage V OUT =20~24V V IN40V Output Current I OUT 1 A Power Dissipation P D Internally Limited W Operating Temperature Range T OPR -40 ~ +85 °C Operating Junction Temperature T J 0~+125 °C Storage Temperature Range T STG -40 ~ +150 °CNote:1. Absolute maximum ratings are stress ratings only and functional device operation is not implied. The devicecould be damaged beyond Absolute maximum ratings.2. The device is guaranteed to meet performance specifications within 0℃~70℃ operating temperature range and assured by design from –40℃~85℃.3.The maximum steady state usable output current are dependent on input voltage, heat sinking, lead length of the package and copper pattern of PCB. The data are showed as electrical characteristics table represents pulse test conditions with junction temperatures specified at the initiation of test.ELECTRICAL CHARACTERISTICS (T J =25℃, P D ≦15W, unless otherwise specified) For 78D33A (V IN =5.8V, I OUT =0.5A, C1=0.33uF, C0=0.1uF)PARAMETER SYMBOLTEST CONDITIONS MIN TYP MAX UNIT I OUT =5mA ~ 1.0A 3.168 3.30 3.432 VOutput Voltage V OUTV IN =5.8~18.3V, I OUT =5mA~1.0A 3.135 3.465 V I OUT =5mA~1.0A 33 mVLoad Regulation ∆V OUTI OUT =0.25A~0.75A 17 mV V IN =5.8~18.3V 33 mVLine Regulation ∆V OUTV IN =5.8~18.3V, I OUT =1.0A 33 mV Quiescent Current I QI OUT ≦1.0A 8.0 mA V IN =5.8~18.3V 1.0 mAQuiescent Current Change ∆I QI OUT =5mA~1.0A0.5 mA Output Noise VoltageeN 10Hz ≦f ≦100kHz 55 µVTemperature coefficient of V OUT ∆V OUT /∆T I OUT =5mA -0.4 mV/°C Ripple Rejection RR V IN =6.3~16.3V,f=120Hz 57 dB Peak Output Current I PEAK 1.8 A Short-Circuit Current I SC V IN =35V 250 mA Dropout VoltageV D 2.0 VFor 78D47A (V IN =9.7V, I OUT =0.5A, C1=0.33uF, C0=0.1uF)PARAMETER SYMBOLTEST CONDITIONS MIN TYP MAX UNITI OUT =5mA~1.0A4.512 4.70 4.888 V Output Voltage V OUT V IN =5.8~18.3V, I OUT =5mA~1.0A 4.465 4.935 VI OUT =5mA~1.0A 47 mV Load Regulation ∆V OUT I OUT =0.25A~0.75A 24 mV V IN =5.8~18.3V 47 mV Line Regulation ∆V OUT V IN =5.8~18.3V, I OUT =1.0A 47 mV Quiescent Current I Q I OUT ≦1.0A 8.0 mA V IN =5.8~18.3V 1.0 mA Quiescent Current Change ∆I Q I OUT =5mA~1.0A0.5 mA Output Noise VoltageeN 10Hz ≦f ≦100kHz40 µV Temperature coefficient of V OUT ∆V OUT /∆T I OUT =5mA -0.6 mV/°C Ripple Rejection RR V IN =6.3~16.3V,f=120Hz62 80 dB Peak Output Current I PEAK1.8 A Short-Circuit Current I SC V IN =35V250 mA Dropout VoltageV D2.0 VFor 78D05A (V IN =10V, I OUT =0.5A, C1=0.33uF, C0=0.1uF)PARAMETER SYMBOLTEST CONDITIONS MIN TYP MAX UNITI OUT =5mA~1.0A4.805.0 5.20 V Output Voltage V OUT V IN =7.5~20V, I OUT =5mA~1.0A 4.75 5.25 VI OUT =5mA~1.0A 50 mV Load Regulation ∆V OUT I OUT =0.25A~0.75A 25 mV V IN =7~25V 50 mV Line Regulation ∆V OUT V IN =7.5~20V, I OUT =1.0A 50 mV Quiescent Current I Q I OUT ≦1.0A 8.0 mA V IN =7.5~20V 1.0 mA Quiescent Current Change ∆I Q I OUT =5mA~1.0A0.5 mA Output Noise VoltageeN 10Hz ≦f ≦100kHz40 µV Temperature coefficient of V OUT ∆V OUT /∆T I OUT =5mA -0.6 mV/°C Ripple Rejection RR V IN =8~18V,f=120Hz62 80 dB Peak Output Current I PEAK1.8 A Short-Circuit Current I SC V IN =35V250 mA Dropout VoltageV D2.0 V For 78D06A (V IN =11V, I OUT =0.5A, C1=0.33uF, C0=0.1uF)PARAMETER SYMBOLTEST CONDITIONS MIN TYP MAX UNIT I OUT =5mA~1.0A5.766.0 6.24 V Output Voltage V OUT V IN =8.5~21V, I OUT =5mA~1.0A 5.7 6.3 VI OUT =5mA~1.0A 60 mV Load Regulation ∆V OUT I OUT =0.25A~0.75A 30 mV V IN =8~25V 60 mV Line Regulation ∆V OUT V IN =8.5~21V, I OUT =1.0A 60 mV Quiescent Current I Q I OUT ≦1.0A 8.0 mA V IN =8.5~21V 1.0 mA Quiescent Current Change ∆I Q I OUT =5mA~1.0A0.5 mA Output Noise VoltageeN 10Hz ≦f ≦100kHz45 µV Temperature coefficient of V OUT ∆V OUT /∆T I OUT =5mA -0.7 mV/°C Ripple Rejection RR V IN =9~19V,f=120Hz59 75 dB Peak Output Current I PEAK1.8 A Short-Circuit Current I SC V IN =35V250 mA Dropout VoltageV D2.0 V For 78D07A (V IN =13V, I OUT =0.5A, C1=0.33uF, C0=0.1uF)PARAMETER SYMBOLTEST CONDITIONS MIN TYP MAX UNIT I OUT =5mA~1.0A6.727.0 7.28 V Output Voltage V OUT V IN =9.5~22V, I OUT =5mA~1.0A 6.65 7.35 VI OUT =5mA~1.0A 70 mV Load Regulation ∆V OUT I OUT =0.25A~0.75A 35 mV V IN =9~25V 70 mV Line Regulation ∆V OUT V IN =9.5~22V, I OUT =1.0A 70 mV Quiescent Current I Q I OUT ≦1.0A 8.0 mA V IN =9.5~22V 1.0 mA Quiescent Current Change ∆I Q I OUT =5mA~1.0A0.5 mA Output Noise VoltageeN 10Hz ≦f ≦100kHz50 µV Temperature coefficient of V OUT ∆V OUT /∆T I OUT =5mA -0.8 mV/°C Ripple Rejection RR V IN =10~20V,f=120Hz59 75 dB Peak Output Current I PEAK1.7 A Short-Circuit Current I SC V IN =35V250 mA Dropout VoltageV D2.0 VFor 78D08A (V IN =14V, I OUT =0.5A, C1=0.33uF, C0=0.1uF)PARAMETER SYMBOLTEST CONDITIONS MIN TYP MAX UNITI OUT =5mA~1.0A7.68 8.0 8.32 V Output Voltage V OUT V IN =10.5~23V, I OUT =5mA~1.0A 7.6 8.4 VI OUT =5mA~1.0A 80 mV Load Regulation ∆V OUT I OUT =0.25A~0.75A 40 mV V IN =10.5~25V 80 mV Line Regulation ∆V OUT V IN =10.5~23V, I OUT =1.0A 80 mV Quiescent Current I Q I OUT ≦1.0A 8.0 mA V IN =10.5~23V 1.0 mA Quiescent Current Change ∆I Q I OUT =5mA~1.0A0.5 mA Output Noise VoltageeN 10Hz ≦f ≦100kHz58 µV Temperature coefficient of V OUT ∆V OUT /∆T I OUT =5mA -0.9 mV/°C Ripple Rejection RR V IN =11.5~21.5V,f=120Hz56 72 dB Peak Output Current I PEAK1.8 A Short-Circuit Current I SC V IN =35V250 mA Dropout VoltageV D2.0 V For 78D09A (V IN =15V, I OUT =0.5A, C1=0.33uF, C0=0.1uF)PARAMETER SYMBOLTEST CONDITIONS MIN TYP MAX UNIT I OUT =5mA~1.0A7.68 8.0 8.32 V Output Voltage V OUT V IN =11.5~24V, I OUT =5mA~1.0A 7.6 8.4 VI OUT =5mA~1.0A 80 mV Load Regulation ∆V OUT I OUT =0.25A~0.75A 40 mV V IN =11.5~25V 80 mV Line Regulation ∆V OUT V IN =11.5~24V, I OUT =1.0A 80 mV Quiescent Current I Q I OUT ≦1.0A 8.0 mA V IN =11.5~24V 1.0 mA Quiescent Current Change ∆I Q I OUT =5mA~1.0A0.5 mA Output Noise VoltageeN 10Hz ≦f ≦100kHz58 µV Temperature coefficient of V OUT ∆V OUT /∆T I OUT =5mA -0.9 mV/°C Ripple Rejection RR V IN =12.5~22.5V,f=120Hz56 72 dB Peak Output Current I PEAK1.8 A Short-Circuit Current I SC V IN =35V250 mA Dropout VoltageV D2.0 V For 78D10A (V IN =16V, I OUT =0.5A, C1=0.33uF, C0=0.1uF)PARAMETER SYMBOLTEST CONDITIONS MIN TYP MAX UNIT I OUT =5mA~1.0A9.60 10.0 10.40 V Output Voltage V OUT V IN =12.5~25V, I OUT =5mA~1.0A 9.5 10.5 VI OUT =5mA~1.0A 100 mV Load Regulation ∆V OUT I OUT =0.25A~0.75A 50 mV V IN =13~25V 100 mV Line Regulation ∆V OUT V IN =13~25V, I OUT =1.0A 100 mV Quiescent Current I Q I OUT ≦1.0A 8.0 mA V IN =12.6V~25V 1.0 mA Quiescent Current Change ∆I Q I OUT =5mA~1.0A0.5 mA Output Noise VoltageeN 10Hz ≦f ≦100kHz58 µV Temperature coefficient of V OUT ∆V OUT /∆T I OUT =5mA -1.1 mV/°C Ripple Rejection RR V IN =13~23V,f=120Hz56 72 dB Peak Output Current I PEAK1.8 A Short-Circuit Current I SC V IN =35V250 mA Dropout VoltageV D2.0 VFor 78D12A (V IN =19V, I OUT =0.5A, C1=0.33uF, C0=0.1uF)PARAMETER SYMBOLTEST CONDITIONS MIN TYP MAX UNITI OUT =5mA~1.0A11.52 12.0 12.48 V Output Voltage V OUT V IN =14.5~27V, I OUT =5mA~1.0A11.4 12.6 V I OUT =5mA~1.0A 120 mV Load Regulation ∆V OUT I OUT =0.25A~0.75A 60 mV V IN =14.5~30V 120 mV Line Regulation ∆V OUT V IN =14.6~27V, I OUT =1.0A 120 mV Quiescent Current I Q I OUT ≦1.0A 8.0 mA V IN =12.6~25V 1.0 mA Quiescent Current Change ∆I Q I OUT =5mA~1.0A0.5 mA Output Noise VoltageeN 10Hz ≦f ≦100kHz75 µV Temperature coefficient of V OUT ∆V OUT /∆T I OUT =5mA -1.5 mV/°C Ripple Rejection RR V IN =15~25V,f=120Hz55 72 dB Peak Output Current I PEAK1.8 A Short-Circuit Current I SC V IN =35V250 mA Dropout VoltageV D2.0 V For 78D15A (V IN =23V, I OUT =0.5A, C1=0.33uF, C0=0.1uF)PARAMETER SYMBOLTEST CONDITIONS MIN TYP MAX UNIT I OUT =5mA~1.0A11.52 12.0 12.48 V Output Voltage V OUT V IN =17.5~30V, I OUT =5mA~1.0A11.4 12.6 V I OUT =5mA~1.0A 120 mV Load Regulation ∆V OUT I OUT =0.25A~0.75A 60 mV V IN =18.5~30V 120 mV Line Regulation ∆V OUT V IN =17.7~30V, I OUT =1.0A 120 mV Quiescent Current I Q I OUT ≦1.0A 8.0 mA V IN =17.5~30V 1.0 mA Quiescent Current Change ∆I Q I OUT =5mA~1.0A0.5 mA Output Noise VoltageeN 10Hz ≦f ≦100kHz75 µV Temperature coefficient of V OUT ∆V OUT /∆T I OUT =5mA -1.5 mV/°C Ripple Rejection RR V IN =18.5~28.5V,f=120Hz55 72 dB Peak Output Current I PEAK1.8 A Short-Circuit Current I SC V IN =35V250 mA Dropout VoltageV D2.0 V For 78D18A (V IN =27V, I OUT =0.5A, C1=0.33uF, C0=0.1uF)PARAMETER SYMBOLTEST CONDITIONS MIN TYP MAX UNIT I OUT =5mA~1.0A17.28 18.0 18.72 V Output Voltage V OUT V IN =21~33V, I OUT =5mA~1.0A 17.1 18.9 VI OUT =5mA~1.0A 180 mV Load Regulation ∆V OUT I OUT =0.25A~0.75A 90 mV V IN =21~33V 180 mV Line Regulation ∆V OUT V IN =21~33V, I OUT =1.0A 180 mV Quiescent Current I Q I OUT ≦1.0A 8.0 mA V IN =21.5~33V 1.0 mA Quiescent Current Change ∆I Q I OUT =5mA~1.0A0.5 mA Output Noise VoltageeN 10Hz ≦f ≦100kHz110 µV Temperature coefficient of V OUT ∆V OUT /∆T I OUT =5mA -2.2 mV/°C Ripple Rejection RR V IN =22~32V,f=120Hz53 69 dB Peak Output Current I PEAK1.8 A Short-Circuit Current I SC V IN =35V250 mA Dropout VoltageV D2.0 VFor 78D24A (V IN =33V, I OUT =0.5A, C1=0.33uF, C0=0.1uF)PARAMETER SYMBOLTEST CONDITIONS MIN TYP MAX UNITI OUT =5mA~1.0A23.04 24.0 24.96 V Output Voltage V OUT V IN =27~38V, I OUT =5mA~1.0A 22.8 25.2 VI OUT =5mA~1.0A 240 mV Load Regulation ∆V OUT I OUT =0.25A~0.75A 120 mV V IN =27~38V 240 mV Line Regulation ∆V OUT V IN =27~38V, I OUT =1.0A 240 mV Quiescent Current I Q I OUT ≦1.0A 8.0 mA V IN =28~38V 1.0 mA Quiescent Current Change ∆I Q I OUT =5mA~1.0A0.5 mA Output Noise VoltageeN 10Hz ≦f ≦100kHz170 µV Temperature coefficient of V OUT ∆V OUT /∆T I OUT =5mA -2.8 mV/°C Ripple Rejection RR V IN =28~38V,f=120Hz50 66 dB Peak Output Current I PEAK1.8 A Short-Circuit Current I SC V IN =35V250 mA Dropout VoltageV D2.0 V。