MAA50-2K121512SBP中文资料

AP1512/A50KHz, 2A/3A PWM Buck DC/DC ConverterFeatures- Output voltage: 3.3V, 5V, 12V and adjustable output version- Adjustable version output voltage range, 1.23V to 37V+4%- 50KHz +15% fixed switching frequency- Voltage mode non-synchronous PWM control - Thermal-shutdown and current-limit protection - ON/OFF shutdown control input - Operating voltage can be up to 60V - Output load current: 2A (for AP1512)3A (for AP1512A)- Low power standby mode- Built-in switching transistor on chip - TO220-5L, TO220-5L(R) and TO263-5L Pb-free packagesApplications- Simple High-efficiency step-down regulator - On-card switching regulators - Positive to negative converterGeneral DescriptionThe AP1512/A is a monolithic IC that design for a step-down DC/DC converter, and own the ability of driving a 2A (3A for AP1512A) load without additional transistor component. Due to reducing the number of external component, the board space can be saved easily. The external shutdown function can be controlled by logic level and then come into standby mode. The internal compensation makes feedback control have good line and load regulation without external design. Regarding protected function, thermal shutdown is to prevent over temperature operating from damage, and current limit is against over current operating of the output switch. The AP1512/A operates at a switching frequency of 50KHz thus allowing smaller sized filter components than what would be needed with lower frequency switching regulators. Other features include a guaranteed +4% tolerance on output voltage under specified input voltage and output load conditions, and +15% on the oscillator frequency. The output version included fixed 3.3V, 5V, 12V, and an adjustable type. The packages are available in a standard 5-lead TO-220 package and a 5-lead TO-263.Pin AssignmentsTO220-5L( Top View )( Top View )TO263-5L INMetal Tab GNDINPin DescriptionsNameDescriptionV IN Operating voltage input Output Switching output Gnd Ground FBOutput voltage feedback controlSD ON/OFF ShutdownAP1512/A50KHz, 2A/3A PWM Buck DC/DC ConverterOrdering InformationPackage T5: TO220-5LK5: TO263-5LOutput Version AP1512 X XX X XPacking Blank : Tube A : TapingBlank : Adjustable -33 : 3.3V -50 : 5.0V -12 : 12VT5R: TO220-5L(R)Part Number Blank: 2A A : 3ABlock DiagramCurrent Source bias1.235V Reference2.5V Regulator50KHz OSC.Start up++_+_Thermal LimitPre-driverComp CompGndOutput V INSDFB220mV200mV2A Switch +__Amp CompFrequecy compen-sation(3A for AP1512A)AP1512/A50KHz, 2A/3A PWM Buck DC/DC ConverterAbsolute Maximum RatingsSymbol Parameter RatingUnit V CC Supply Voltage +63 V V SD ON/OFF Pin input voltage -0.3 to +40 V V FB Feedback Pin voltage -0.3 to +40V V OUT Output voltage to Ground -1V P D Power dissipation Internally limited W T ST Storage temperature -65 to +150 o C T OP Operating temperature -40 to +125 o C V OP Operating voltage+4.5 to +60VElectrical Characteristics (All Output Voltage Versions)Unless otherwise specified, V IN =30V for all version. I LOAD = 0.5ASymbol ParameterConditionsMin.Typ.Max. Unit 8I BFeedback bias currentV FB =1.3V(Adjustable version only)5 10µA42.5 50 57.5F OSC oscillator frequency40 60KHz1.4V SAT saturation voltage I OUT =2A no outside circuitV FB =0V force driver on1.3 1.5VMax. Duty Cycle(ON) V FB =0V force driver on100DCMin. Duty cycle(OFF) V FB =12V force driver off%4.5I CL current limit for AP1512 peak currentno outside circuitV FB =0V force driver on 2.5 3 5.5A5I CL current limit for AP1512A peak current no outside circuitV FB =0V force driver on3.2 4 6 A Output = 0no outside circuitV FB =12V force driver off-250 uA I L Output = -1 Output leakage currentV IN =60V -2 -60 mA I Q Quiescent Current V FB =12V force driver off 5 10 mA450 I STBYStandby Quiescent Current ON/OFF pin=5VV IN =60V 350 500uA V IL Low (regulator ON) - 0.6 V IH ON/OFF pin logic inputthreshold voltage High (regulator OFF) 2.0 1.3 - VI H ON/OFF pin logic input currentV LOGIC =2.5V (OFF) 0 -5I L ON/OFF pin input current V LOGIC =0.5V (ON) -0.8 -10uA TO220-5L 2.5 θJC Thermal Resistance TO263-5L Junction to case3.5 oC/WTO220-5L 28 θJA Thermal ResistanceWith copper area ofapproximately 3 in 2TO263-5L Junction to ambient 23 oC/WAP1512/A50KHz, 2A/3A PWM Buck DC/DC ConverterElectrical Characteristics (Continued)AP1512Symbol Parameter Conditions Typ. Limit Unit AP1512-ADJ FB V Output Feedback 10V < V IN < 60V 0.2A < I LOAD < 2AV OUT programmed for 3V 1.231.193/1.18 1.267/1.28 V V MIN V MAX AP1512-3.3V OUT V Output voltage 10V < V IN < 60V 0.2A < I LOAD < 2A 3.3 3.168/3.135 3.432/3.465 V V MIN V MAX AP1512-5VOUT V Output voltage 10V < V IN < 60V 0.2A < I LOAD < 2A 5 4.8/4.75 5.2/5.25 V V MIN V MAX OUT V Output voltage15V < V IN < 60V 0.2A < I LOAD < 2A12 11.52/11.4 12.48/12.6V V MIN V MAX AP1512-12VηEfficiency V IN = 30V, I LOAD = 2A 83 % AP1512ASymbol Parameter Conditions Typ. Limit Unit AP1512A-ADJ FB V Output Feedback 10V < V IN < 60V 0.2A < I LOADV OUT programmed for 3V 1.231.193/1.18 1.267/1.28 V V MIN V MAX AP1512A-3.3V OUT V Output voltage 10V < V IN < 60V 0.2A < I LOAD 3.3 3.168/3.135 3.432/3.465 V V MIN V MAX AP1512A-5VOUT VOutput voltage10V < V IN < 60V 0.2A < I LOAD54.8/4.755.2/5.25V V MIN V MAX OUT V Output voltage15V < V IN < 60V 0.2A < I LOAD12 11.52/11.4 12.48/12.6V V MIN V MAX AP1512A-12VηEfficiency V IN = 30V, I LOAD = 3A80%Specifications with boldface type are for full operating temperature range, the other type are for T J =25ºC.Typical Performance CharacteristicsAP1512A Current Limit v.s. Temperature(Vcc=60V, Vout=5V)33.23.43.63.84-50050100150Temperature (TA) (°C)C u r r e n t L i m i t (A )AP1512A Efficiency v.s. Supply Voltage(Vout=5V, Iout=3A)10203040506070809010001224364860Supply Voltage(V)E f f i c i e n c y (%)AP1512/A50KHz, 2A/3A PWM Buck DC/DC ConverterTypical Performance Characteristics (Continued)AP1512 Efficiency v.s. Temperature(Vin=12V,Vout=5V,Io=2A)102030405060708090100-50-30-101030507090*********Temperature (TA) (°C)E f f i c i e n c y (%)AP1512 Efficiency v.s. Temperature(Vin=12V,Vout=3.3V,Io=2A)102030405060708090100-50-30-101030507090*********Temperature (TA) (°C)E f f i c i e n c y (%)AP1512 Supply Current v.s. Temperature(Vcc=12V , No Load ,Von/off =0V(Switch ON) ,Von/off =5V(Switch OFF))12345678-40-25-105203550658095110125S u p p l y C u r r e n t (m A )Temperature (TA) (°C)Switch ON102030405060708090100-40-25-105203550658095110125S u p p l y C u r r e n t (u A )Temperature (TA) (°C)Switch OFFAP1512 Output Voltage v.s. Temperature(Vin=12V, Vout=5V, Io=1A)4.704.754.804.854.904.955.005.055.10-50050100150O u t p u t V o l t a g e (V )Temperature (TA) (°C)AP1512 Threshold Voltage v.s. Temperature(Vcc=12V, Vout=5V)00.20.40.60.811.21.41.6-50050100150T h r e s h o l d V o l t a g e (V )Temperature (TA) (°C)AP1512/A50KHz, 2A/3A PWM Buck DC/DC ConverterTypical Performance Characteristics (Continued)AP1512 Frequency v.s. Temperature(Vcc=12V, Io=1A, Vout=5V)4045505560-50-30-101030507090110130150Temperature (TA) (°C)F r e q u e n c y (K H z )AP1512 Current Limit v.s. Temperature(Vcc=60V, Vout=5V)2.833.23.43.6-5050100150C u r r e n t L i m i t (A )Temperature (TA) (°AP1512 Quiescent Current v.s. Supply Voltage(force driver off)5.25.45.65.866.21224364860Q u i e s c e n t C u r r e n t (A )Supply Voltage(V)AP1512/A50KHz, 2A/3A PWM Buck DC/DC ConverterTypical Application Circuit(1) Adjustable Type CircuitA. Vin=10V~60V, Vout=5V; Iout=0.3A~2A, Iout below 0.3A DCMC51nL147uH12R23KVinC21uD1SR360ON/OFFR31KC1100uF/100VAP1512/A15243VinSDOUTPUTFBGND 0.1uC3470uF/16VC7B. Vin=10V~60V, Vout=3.3V, Iout=0.3A~2A, Iout below 0.3A DCMC51nL147uH12R22KVinC21uD1SR360ON/OFFR31.2KC1100uF/100VAP1512/A15243VinSDOUTPUTFBGND 0.1uC3470uF/16VC7(2) Fixed Type CircuitA. Vin=10V~60V, Vout=5V, Iout=0.7A~2A, Iout below 0.7A DCML147uH12VinC21uD1SR360ON/OFFC1100uF/100VVoutAP1512/A15243VinSDOUTPUTFBGND 10nC3470uF/16VC7AP1512/A50KHz, 2A/3A PWM Buck DC/DC ConverterTypical Application Circuit (Continued)B. Vin=10V~60V, Vout=3.3V, Iout=0.7A~2A, Iout below 0.7A DCML133uH12VinC23.3uD1SR360ON/OFFC1220uF/100VVoutAP1512/A15243VinSDOUTPUTFBGND 3.3uC31500uF/16VC7Function Description+V INThis is the positive input supply for the IC switching regulator. A suitable input bypass capacitor must be present at this pin to minimize voltage transients and to supply the switching currents needed by the regulator.GroundCircuit ground.OutputInternal switch. The voltage at this pin switches between (+V IN – V SAT ) and approximately – 0.5V, with a duty cycle of approximately V OUT / V IN . To minimize coupling to sensitive circuitry, the PC board copper area connected to this pin should be kept a minimum.FeedbackSenses the regulated output voltage to complete the feedback loop.ON /OFFAllows the switching regulator circuit to be shutdown using logic level signals thus dropping the total input supply current to approximately 150uA. Pulling this pin below a threshold voltage of approximately 1.3V turns the regulator on, and pulling this pin above 1.3V (up to a maximum of 40V) shuts the regulator down. If this shutdown feature is not needed, the SD pin can be wired to the ground pin or it can be left open, in either case the regulator will be in the ON condition.Thermal ConsiderationsThe AP1512/A is available in two packages, a 5-pin TO-220 and a 5-pin surface mount TO-263.The TO-220 package needs a heat sink under most conditions. The size of the heatsink depends on the input voltage, the output voltage, the load current and the ambient temperature. The AP1512/A junction temperature rises above ambient temperature for a 2A load and different input and output voltages. The data for these curves was taken with the AP1512/A (TO-220 package) operating as a buckswitching regulator in an ambient temperature of 25o C (still air). These temperature rise numbers are all approximate and there are many factors that can affect these temperatures. Higher ambient temperatures require more heat sinking.The TO-263 surface mount package tab is designed to be soldered to the copper on a printed circuit board. The copper and the board are the heat sink for this package and the other heat producing components, such as the catch diode and inductor. The PC board copper area that the package is soldered to should be at least 0.4 in 2, and ideally should have 2 or more square inches of 2 oz. Additional copper area improves the thermal characteristics, but with copper areas greater than approximately 6 in 2, only small improvements in heat dissipation are realized. If further thermal improvements are needed, double sided, multilayer PC board with large copper areas and/or airflow are recommended.AP1512/A50KHz, 2A/3A PWM Buck DC/DC ConverterFunction Description (Continued)The AP1512/A (TO-263 package) junction temperature rise above ambient temperature with a 2A load for various input and output voltages. This data was taken with the circuit operating as a buck switching regulator with all components mounted on a PC board to simulate the junction temperature under actual operating conditions. This curve can be used for a quick check for the approximate junction temperature for various conditions, but be aware that there are many factors that can affect the junction temperature. When load currents higher than 2A are used, double sided or multilayer PC boards with large copper areas and/or airflow might be needed, especially for high ambient temperatures and high output voltages.For the best thermal performance, wide copper traces and generous amounts of printed circuit board copper should be used in the board layout. (Once exception to this is the output (switch) pin, which should not have large areas of copper.) Large areas of copper provide the best transfer of heat (lower thermal resistance) to the surrounding air, and moving air lowers the thermal resistance even further.Package thermal resistance and junction temperature rise numbers are all approximate, and there are many factors that will affect these numbers. Some of these factors include board size, shape, thickness, position, location, and even board temperature. Other factors are, trace width, total printed circuit copper area, copper thickness, single or double-sided, multilayer board and the amount of solder on the board. The effectiveness of the PC board to dissipate heat also depends on the size, quantity and spacing of other components on the board, as well as whether the surrounding air is still or moving. Furthermore, some of these components such as the catch diode will add heat to the PC board and the heat can vary as the input voltage changes. For the inductor, depending on the physical size, type of core material and the DC resistance, it could either act as a heat sink taking heat away from the board, or it could add heat to the board.Marking Information(1) TO263-5L1512X-XX Blank: ADJ ( Top View )"02" = 2002"01" = 2001YY WW X01~52~Part Number:A: AP1512A(2) TO220-5L1512X-XX ID codeYear:"02" = 2002"01" = 2001YY WW XXth week:01~52~Blank: ADJ LogoPart Number:-Output Type: -33: 3.3V -50: 5.0V -12: 1.2V Blank: AP1512A: AP1512AAP1512/A 50KHz, 2A/3A PWM Buck DC/DC ConverterPackage Information(1) Package Type: TO220-5LD QEbe1AJ1FCΦPH1LeDimensions In Millimeters Dimensions In InchesSymbolMin. Nom. Max. Min. Nom. Max.A 4.07 4.45 4.82 0.160 0.175 0.190b 0.76 0.89 1.02 0.030 0.035 0.040C 0.36 0.50 0.64 0.014 0.020 0.025D 14.22 14.86 15.50 0.560 0.585 0.610E 9.78 10.16 10.54 0.385 0.400 0.415e 1.57 1.71 1.85 0.062 0.067 0.073e1 6.68 6.81 6.93 0.263 0.268 0.273F 1.14 1.27 1.40 0.045 0.050 0.055H1 5.46 6.16 6.86 0.215 0.243 0.270 J1 2.29 2.74 3.18 0.090 0.108 0.125 L 13.21 13.97 14.73 0.520 0.550 0.580 Øp 3.68 3.81 3.94 0.145 0.150 0.155 Q 2.54 2.73 2.92 0.100 0.107 0.115AP1512/A 50KHz, 2A/3A PWM Buck DC/DC ConverterPackage Information (Continued)(2) Package Type: TO263-5LEL2e B DLAC2CL11.02.515.710.99.11.7Land Pattern Recommendation (Unit: mm)Dimensions In Millimeters Dimensions In InchesSymbolMin. Nom. Max. Min. Nom. Max.A 4.07 4.46 4.85 0.160 0.176 0.191B 0.66 0.84 1.02 0.026 0.033 0.040C 0.36 0.50 0.64 0.014 0.020 0.025C2 1.14 1.27 1.40 0.045 0.050 0.055D 8.65 9.15 9.65 0.341 0.360 0.380E 9.78 10.16 10.54 0.385 0.400 0.415e 1.57 1.71 1.85 0.062 0.068 0.073L 14.61 15.24 15.88 0.575 0.600 0.625 L1 2.29 2.54 2.79 0.090 0.100 0.110 L2 - - 2.92 - - 0.115AP1512/A50KHz, 2A/3A PWM Buck DC/DC ConverterPackage Information (Continued)(3) Package Type: TO220-5L(R) Mechanical drawingEQDbAFH1d1d2J3J1J2eH2H3AJ1J2J3EDimensions In Millimeters Dimensions In Inches SymbolMin. Nom. Max. Min. Nom. Max.A 4.4 4.6 4.7 0.175 0.180 0.185b 0.7 0.8 0.9 0.027 0.032 0.037 D 8.4 8.7 8.9 0.330 0.340 0.350 d1 1.0 0.039 d2 6.3 0.248 E 9.91 10.16 10.41 0.390 0.400 0.410 e 1.6 1.7 1.8 0.062 0.067 0.072 F 1.2 1.25 1.3 0.048 0.050 0.052 H1 6.4 0.250 H2 20.8 21.6 22.4 0.820 0.850 0.880 H3 23.9 24.7 25.5 0.942 0.972 1.002 J1 2.7 0.105 J2 3.7 4.5 5.3 0.147 0.177 0.207 J3 8.4 0.331 Q 2.5 2.8 3.0 0.100 0.110 0.120。

LM78M12中⽂资料LM341/LM78MXX Series3-Terminal Positive Voltage RegulatorsGeneral DescriptionThe LM341and LM78MXX series of three-terminal positive voltage regulators employ built-in current limiting,thermal shutdown,and safe-operating area protection which makes them virtually immune to damage from output overloads.With adequate heatsinking,they can deliver in excess of 0.5A output current.Typical applications would include local (on-card)regulators which can eliminate the noise and de-graded performance associated with single-point regulation.Featuresn Output current in excess of 0.5A n No external componentsn Internal thermal overload protection n Internal short circuit current-limitingn Output transistor safe-area compensationnAvailable in TO-220,TO-39,and TO-252D-PAK packagesn Output voltages of 5V,12V,and 15VConnection DiagramsTO-39Metal Can Package (H)DS010484-5Bottom ViewOrder Number LM78M05CH,LM78M12CH or LM78M15CHSee NS Package Number H03ATO-220Power Package (T)DS010484-6Top ViewOrder Number LM341T-5.0,LM341T-12,LM341T-15,LM78M05CT,LM78M12CT or LM78M15CTSee NS Package Number T03BTO-252DS010484-19Top ViewOrder Number LM78M05CDT See NS Package Number TD03BJuly 1999LM341/LM78MXX Series 3-Terminal Positive Voltage Regulators1999National Semiconductor Corporation /doc/96ef4d46852458fb770b5641.htmlAbsolute Maximum Ratings(Note1)If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications.Lead Temperature(Soldering,10seconds)TO-39Package(H)300?C TO-220Package(T)260?C Storage Temperature Range?65?C to+150?C Operating Junction TemperatureRange?40?C to+125?C Power Dissipation(Note2)Internally Limited Input Voltage5V≤V O≤15V35V ESD Susceptibility TBDElectrical CharacteristicsLimits in standard typeface are for T J=25?C,and limits in boldface type apply over the?40?C to+125?C operating temperature range.Limits are guaranteed by production testing or correlation techniques using standard Statistical Quality Control(SQC) methods.LM341-5.0,LM78M05CUnless otherwise specified:V IN=10V,C IN=0.33µF,C O=0.1µFSymbol Parameter Conditions Min Typ Max Units V O Output Voltage I L=500mA 4.8 5.0 5.2V5mA≤I L≤500mA 4.75 5.0 5.25P D≤7.5W,7.5V≤V IN≤20VV R LINE Line Regulation7.2V≤V IN≤25V I L=100mA50mVI L=500mA100V R LOAD Load Regulation5mA≤I L≤500mA100I Q Quiescent Current I L=500mA410.0mA ?I Q Quiescent Current Change5mA≤I L≤500mA0.57.5V≤V IN≤25V,I L=500mA 1.0V n Output Noise Voltage f=10Hz to100kHz40µVElectrical CharacteristicsLimits in standard typeface are for T J=25?C,and limits in boldface type apply over the?40?C to+125?C operating temperature range.Limits are guaranteed by production testing or correlation techniques using standard Statistical Quality Control(SQC) methods.(Continued)LM341-12,LM78M12CUnless otherwise specified:V IN=19V,C IN=0.33µF,C O=0.1µFSymbol Parameter Conditions Min Typ Max UnitsV O Output Voltage I L=500mA11.51212.5V5mA≤I L≤500mA11.41212.6P D≤7.5W,14.8V≤V IN≤27VV R LINE Line Regulation14.5V≤V IN≤30V I L=100mA120mVI L=500mA240V R LOAD Load Regulation5mA≤I L≤500mA240I Q Quiescent Current I L=500mA410.0mAI Q Quiescent Current Change5mA≤I L≤500mA0.514.8V≤V IN≤30V,I L=500mA 1.0V n Output Noise Voltage f=10Hz to100kHz75µVRipple Rejection f=120Hz,I L=500mA69dBV IN Input Voltage Required I L=500mA17.6V to Maintain Line RegulationV O Long Term Stability I L=500mA60mV/khrs Note1:Absolute maximum ratings indicate limits beyond which damage to the component may occur.Electrical specifications do not apply when operating the de-vice outside of its rated operating conditions.Note2:The typical thermal resistance of the three package types is:T(TO-220)package:θ(JA)=60?C/W,θ(JC)=5?C/WH(TO-39)package:θ(JA)=120?C/W,θ(JC)=18?C/WDT(TO-252)package:θ(JA)=92?C/W,θ(JC)=10?C/W3/doc/96ef4d46852458fb770b5641.htmlSchematic DiagramDS010484-1 /doc/96ef4d46852458fb770b5641.html 4 Typical Performance CharacteristicsPeak Output CurrentDS010484-10Ripple RejectionDS010484-11Ripple RejectionDS010484-12Dropout VoltageDS010484-13Output Voltage(Normalizedto1V at T J=25?C)DS010484-14Quiescent CurrentDS010484-15/doc/96ef4d46852458fb770b5641.html 5Typical Performance Characteristics(Continued)Design ConsiderationsThe LM78MXX/LM341XX fixed voltage regulator series has built-in thermal overload protection which prevents the de-vice from being damaged due to excessive junction tem-perature.The regulators also contain internal short-circuit protection which limits the maximum output current,and safe-area pro-tection for the pass transistor which reduces the short-circuit current as the voltage across the pass transistor is in-creased.Although the internal power dissipation is automatically lim-ited,the maximum junction temperature of the device must be kept below +125?C in order to meet data sheet specifica-tions.An adequate heatsink should be provided to assure this limit is not exceeded under worst-case operating condi-tions (maximum input voltage and load current)if reliable performance is to be obtained).1.0Heatsink ConsiderationsWhen an integrated circuit operates with appreciable cur-rent,its junction temperature is elevated.It is important to quantify its thermal limits in order to achieve acceptable per-formance and reliability.This limit is determined by summing the individual parts consisting of a series of temperature rises from the semiconductor junction to the operating envi-ronment.A one-dimension steady-state model of conduction heat transfer is demonstrated in The heat generated at thedevice junction flows through the die to the die attach pad,through the lead frame to the surrounding case material,to the printed circuit board,and eventually to the ambient envi-ronment.Below is a list of variables that may affect the ther-mal resistance and in turn the need for a heatsink.R θJC (Component Variables)R θCA (Application Variables)Leadframe Size &Material Mounting Pad Size,Material,&LocationNo.of Conduction Pins Placement of Mounting Pad Die SizePCB Size &Material Die Attach MaterialTraces Length &WidthMolding Compound Size and MaterialAdjacent Heat Sources Volume of Air Air FlowAmbient Temperature Shape of Mounting PadQuiescent CurrentDS010484-16Output ImpedanceDS010484-17Line Transient Response DS010484-7Load Transient ResponseDS010484-8/doc/96ef4d46852458fb770b5641.html6Design Considerations(Continued)The LM78MXX/LM341XX regulators have internal thermal shutdown to protect the device from over-heating.Under all possible operating conditions,the junction temperature of the LM78MXX/LM341XX must be within the range of 0?C to 125?C.A heatsink may be required depending on the maxi-mum power dissipation and maximum ambient temperature of the application.To determine if a heatsink is needed,the power dissipated by the regulator,P D ,must be calculated:I IN =I L +I GP D =(V IN ?V OUT )I L +V IN I Gshows the voltages and currents which are present in the circuit.The next parameter which must be calculated is the maxi-mum allowable temperature rise,T R (max):θJA =TR (max)/P D If the maximum allowable value for θJA ?C/w is found to be ≥60?C/W for TO-220package or ≥92?C/W for TO-252pack-age,no heatsink is needed since the package alone will dis-sipate enough heat to satisfy these requirements.If the cal-culated value for θJA fall below these limits,a heatsink is required.As a design aid,Table 1shows the value of the θJA of TO-252for different heatsink area.The copper patterns that we used to measure these θJA are shown at the end of the Application Note Section.reflects the same test results as what are in the Table 1shows the maximum allowable power dissipation vs.ambi-ent temperature for theTO-252device.shows the maximum allowable power dissipation vs.copper area (in 2)for the TO-252device.Please see AN1028for power enhancement techniques to be used with TO-252package.TABLE 1.θJA Different Heatsink AreaLayoutCopper AreaThermal Resistance Top Sice (in 2)*Bottom Side (in 2)(θJA ,?C/W)TO-25210.0123010320.06608730.306040.5305450.7605261047700.284800.470900.6631000.857110157120.0660.06689130.1750.17572140.2840.28461150.3920.39255160.50.553*Tab of device attached to topside copperDS010484-23FIGURE 1.Cross-sectional view of Integrated Circuit Mounted on a printed circuit board.Note that the case temperature is measured at the point where the leadscontact with the mounting pad surface DS010484-24FIGURE 2.Power Dissipation Diagram/doc/96ef4d46852458fb770b5641.html 7Design Considerations(Continued)Typical ApplicationDS010484-20FIGURE 3.θJA vs.2oz Copper Area for TO-252DS010484-22FIGURE 4.Maximum Allowable Power Dissipation vs.Ambient Temperature for TO-252DS010484-21FIGURE 5.Maximum Allowable Power Dissipation vs.2oz.Copper Area for TO-252DS010484-9*Required if regulator input is more than 4inches from input filter capacitor (or if no input filter capacitor is used).**Optional for improved transient response./doc/96ef4d46852458fb770b5641.html 8 Physical Dimensions inches(millimeters)unless otherwise notedTO-39Metal Can Package(H)Order Number LM78M05CH,LM78M12CH or LM78M15CHNS Package Number H03A9/doc/96ef4d46852458fb770b5641.htmlPhysical Dimensions inches(millimeters)unless otherwise noted(Continued)TO-220Power Package(T)Order Number LM341T-5.0,LM341T-12,LM341T-15,LM78M05CT,LM78M12CT or LM78M15CT NS Package Number T03B/doc/96ef4d46852458fb770b5641.html 10Physical Dimensionsinches (millimeters)unless otherwise noted (Continued)LIFE SUPPORT POLICYNATIONAL’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT AND GENERAL COUNSEL OF NATIONAL SEMICONDUCTOR CORPORATION.As used herein:1.Life support devices or systems are devices or systems which,(a)are intended for surgical implant into the body,or (b)support or sustain life,and whose failure to perform when properly used in accordance with instructions for use provided in the labeling,can be reasonably expected to result in a significant injury to the user.2.A critical component is any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system,or to affect its safety or effectiveness.National Semiconductor Corporation AmericasTel:1-800-272-9959Fax:1-800-737-7018Email:support@/doc/96ef4d46852458fb770b5641.htmlNational Semiconductor EuropeFax:+49(0)180-5308586Email:europe.support@/doc/96ef4d46852458fb770b5641.htmlDeutsch Tel:+49(0)180-5308585English Tel:+49(0)180-5327832Fran?ais Tel:+49(0)180-5329358Italiano Tel:+49(0)180-5341680National Semiconductor Asia Pacific Customer Response Group Tel:65-2544466Fax:65-2504466Email:sea.support@/doc/96ef4d46852458fb770b5641.htmlNational Semiconductor Japan Ltd.Tel:81-3-5639-7560Fax:81-3-5639-7507/doc/96ef4d46852458fb770b5641.htmlTO-252Order Number LM78M05CDT NS Package Number TD03BLM341/LM78MXX Series 3-Terminal Positive Voltage RegulatorsNational does not assume any responsibility for use of any circuitry described,no circuit patent licenses are implied and National reserves the right at any time without notice to change said circuitry andspecifications.。

元器件交易网
SMAJ5.0(C)A - SMAJ170(C)A
400W SURFACE MOUNT TRANSIENT VOLTAGE SUPPRESSOR Features
· · · · · · · 400W Peak Pulse Power Dissipation 5.0V - 170V Standoff Voltages Glass Passivated Die Construction Uni- and Bi-Directional Versions Available Excellent Clamping Capability Fast Response Time Plastic Material: UL Flammability Classification Rating 94V-0 Case: SMA, Transfer Molded Epoxy Terminals: Solderable per MIL-STD-202, Method 208 Polarity Indicator: Cathode Band (Note: Bi-directional devices have no polarity indicator.) Marking: Date Code and Marking Code See Page 3 Weight: 0.064 grams (approx.)
(A) 43.5 38.8 35.7 33.3 31.0 29.4 27.7 26.0 23.5 22.0 20.1 18.6 17.2 16.4 15.3 14.5 13.7 12.3 11.2 10.3 9.5 8.8 8.3 7.5 6.9 6.2 5.7 5.5 5.2 4.9 4.6 4.3 4.1 3.9 3.5 3.3 2.2 2.9 2.7 2.5 2.3 2.0 1.9 1.6 1.5 1.4

位号 F1 C1 D1~D4 D5 D6 ZD1 C2 C4 C6 C3 C5 IC1 IC2
数量 1 1 4 1 1 1 1 1 1 1 1 1 1
备注
10

AM-12A 高性能开关电源控制芯片
14 色环电阻器 100K/0.25W R1
1
15
3K/0.25W
460 480 500 V
开关管耐压
Ioc=1mA
700 --- --- V
开关管电流
Vcc=5V，Fb=1.6 V ----3.6V 320 360 400 mA
峰值电流保护
Vcc=5V，Fb=1.6 V ----3.6V 380 400 420 mA
振荡频率
Vcc=5V，Fb=1.6 V ----2.8V 60 65 70 KHz
2
GND 接地引脚。
3
Fb 反馈控制端。
4
Vcc 供电引脚。
输出引脚，连接芯片内高压开关管 Collector 端，与开
5678 Collector 关变压器相连。
四、内部电路框图
2

AM-12A 高性能开关电源控制芯片 五、极限参数
供电电压 Vcc ----------------------------------------------- -0.3V--9V
4

AM-12A 高性能开关电源控制芯片 引起电路的误动作，在电路开通时启动一个前沿消隐电路将尖峰电流去除， 消隐时间为 250nS），控制端 Fb 电压经斜坡补偿后与取样电阻上的电压相加 后与 0.6V 的基准电压相比较，当电压高于基准电压时比较器输出低电平， 触发器的 Q1，Q2 输出低电平，高压晶体管与功率 MOS 管同时关断， COLLECTOR 端电压上升，电路进入反激工作，在下一个振荡周期到时，电 路将重新开始导通工作。 工作时序图：