LM2596 (Скамко)

LM2596SIMPLE SWITCHER ® Power Converter 150 kHz3A Step-Down Voltage RegulatorGeneral DescriptionFeaturesThe LM2596 series of regulators are monolithic integratedcircuits that provide all the active functions for a step-down(buck) switching regulator, capable of driving a 3A load withexcellent line and load regulation. These devices are available in fixed output voltages of 3.3V, 5V, 12V, and an adjustable output version.Requiring a minimum number of external components, theseregulators are simple to use and include internal frequencycompensation†, and a fixed-frequency oscillator.The LM2596 series operates at a switching frequency of150 kHz thus allowing smaller sized filter components thanwhat would be needed with lower frequency switching regulators.

Available in a standard 5-lead TO-220 package withseveral different lead bend options, and a 5-lead TO-263surface mount package.A standard series of inductors are available from severaldifferent manufacturers optimized for use with the LM2596series. This feature greatly simplifies the design ofswitch-mode power supplies.Other features include a guaranteed ± 4% tolerance on output voltage under specified input voltage and output loadconditions, and ± 15% on the oscillator frequency. Externalshutdown is included, featuring typically 80 µA standby current. Self protection features include a two stage frequencyreducing current limit for the output switch and an overtemperature shutdown for complete protection under faultconditions.n 3.3V, 5V, 12V, and adjustable output versionsn Adjustable version output voltage range, 1.2V to 37V± 4% max over line and load conditionsn Available in TO-220 and TO-263 packagesn Guaranteed 3A output load currentn Input voltage range up to 40Vn Requires only 4 external componentsn Excellent line and load regulation specificationsn 150 kHz fixed frequency internal oscillatorn TTL shutdown capabilityn Low power standby mode, IQ typically 80 µAn High efficiencyn Uses readily available standard inductorsn Thermal shutdown and current limit protectionTypical ApplicationApplicationsn Simple high-efficiency step-down (buck) regulatorn On-card switching regulatorsn Positive to negative converterNote: †Patent Number 5,382,918.(Fixed Output VoltageVersions)01258301SIMPLE SWITCHER ® and Switchers Made Simple ® are registered trademarks of National Semiconductor Corporation.© 2002 National Semiconductor CorporationDS012583www.national.comLM2596 SIMPLE SWITCHER Power Converter 150 kHz 3A Step-Down Voltage RegulatorMay 2002LM2596Connection Diagrams and Ordering InformationBent and Staggered Leads, Through HolePackage5-Lead TO-220 (T)Surface Mount Package5-Lead TO-263 (S)0125830301258302Order Number LM2596S-3.3, LM2596S-5.0,LM2596S-12 or LM2596S-ADJSee NS Package Number TS5BOrder Number LM2596T-3.3, LM2596T-5.0,LM2596T-12 or LM2596T-ADJSee NS Package Number T05Dwww.national.com2Human Body Model (Note 2)(Note 1)Lead TemperatureIf Military/Aerospace specified devices are required,please contact the National Semiconductor Sales Office/Distributors for availability and specifications.Maximum Supply VoltageON /OFF Pin Input Voltage2 kVS Package45VVapor Phase (60 sec.)+215˚CInfrared (10 sec.)+245˚C−0.3 ≤ V ≤ +25VT Package (Soldering, 10 sec.)+260˚C−0.3 ≤ V ≤+25VMaximum Junction Temperature+150˚CFeedback Pin VoltageOutput Voltage to Ground(Steady State)−1VPower DissipationInternally limitedStorage Temperature Range−65˚C to +150˚COperating Conditions−40˚C ≤ TJ ≤ +125˚CTemperature RangeSupply VoltageESD Susceptibility4.5V to 40VLM2596-3.3Electrical CharacteristicsSpecifications with standard type face are for TJ = 25˚C, and those with boldface type apply over full Operating Temperature RangeLM2596-3.3SymbolParameterConditionsTyp(Note 3)Limit(Note 4)Units(Limits)SYSTEM PARAMETERS (Note 5) Test Circuit Figure 1VOUTηOutput VoltageEfficiency4.75V ≤ VIN ≤ 40V, 0.2A ≤ ILOAD ≤ 3AVIN = 12V, ILOAD = 3A3.3V3.168/3.135V(min)3.432/3.465V(max)73%LM2596-5.0Electrical CharacteristicsSpecifications with standard type face are for TJ = 25˚C, and those with boldface type apply over full Operating Temperature RangeLM2596-5.0SymbolParameterConditionsTyp(Note 3)Limit(Note 4)Units(Limits)SYSTEM PARAMETERS (Note 5) Test Circuit Figure 1VOUTηOutput VoltageEfficiency7V ≤ VIN ≤ 40V, 0.2A ≤ ILOAD ≤ 3AVIN = 12V, ILOAD = 3A5.0V4.800/4.750V(min)5.200/5.250V(max)80%LM2596-12Electrical CharacteristicsSpecifications with standard type face are for TJ = 25˚C, and those with boldface type apply over full Operating Temperature RangeLM2596-12SymbolParameterConditionsTyp(Note 3)Limit(Note 4)Units(Limits)SYSTEM PARAMETERS (Note 5) Test Circuit Figure 1VOUTηOutput VoltageEfficiency15V ≤ VIN ≤ 40V, 0.2A ≤ ILOAD ≤ 3AVIN = 25V, ILOAD = 3A12.0903V11.52/11.40V(min)12.48/12.60V(max)%www.national.comLM2596Absolute Maximum RatingsLM2596LM2596-ADJElectrical CharacteristicsSpecifications with standard type face are for TJ = 25˚C, and those with boldface type apply over full Operating Temperature RangeLM2596-ADJSymbolParameterConditionsTyp(Note 3)Limit(Note 4)Units(Limits)SYSTEM PARAMETERS (Note 5) Test Circuit Figure 1VFBFeedback Voltage4.5V ≤ VIN ≤ 40V, 0.2A ≤ ILOAD ≤ 3A1.230VVOUT programmed for 3V.

Circuit of Figure 1ηEfficiencyVIN = 12V, VOUT = 3V, ILOAD = 3A1.193/1.180V(min)1.267/1.280V(max)73%All Output Voltage VersionsElectrical CharacteristicsSpecifications with standard type face are for TJ = 25˚C, and those with boldface type apply over full Operating Temperature Range. Unless otherwise specified, VIN = 12V for the 3.3V, 5V, and Adjustable version and VIN = 24V for the 12V version.

ILOAD = 500 mALM2596-XXSymbolParameterConditionsTyp(Note 3)Limit(Note 4)Units(Limits)DEVICE PARAMETERSIbfOVSATDCICLILFeedback Bias CurrentOscillator FrequencySaturation VoltageAdjustable Version Only, VFB = 1.3V(Note 6)IOUT = 3A (Notes 7, 8)(Note 8)100Min Duty Cycle (OFF)(Note 9)0Current LimitPeak Current (Notes 7, 8)127/110kHz(min)173/173kHz(max)1.4/1.5V(max)kHzQuiescent Current(Note 9)ISTBYStandby Quiescent CurrentON/OFF pin = 5V (OFF)V%4.5Output = 0V (Notes 7, 9)IQThermal ResistancenA (max)1.16Max Duty Cycle (ON)Output Leakage CurrentnA50/100150Output = −1V (Note 10)θJC10A3.6/3.4A(min)6.9/7.5A(max)50µA(max)30mA(max)2mA5(Note 10)mA10mA(max)200/250µA(max)80µATO-220 or TO-263 Package, Junction to Case2˚C/WθJATO-220 Package, Junction to Ambient (Note 11)50˚C/WθJATO-263 Package, Junction to Ambient (Note 12)50˚C/WθJATO-263 Package, Junction to Ambient (Note 13)30˚C/WθJATO-263 Package, Junction to Ambient (Note 14)20˚C/W1.3VON/OFF CONTROL Test Circuit Figure 1ON /OFF Pin Logic InputVIHThreshold VoltageVILwww.national.comLow (Regulator ON)0.6V(max)High (Regulator OFF)2.0V(min)4LM2596All Output Voltage VersionsElectrical Characteristics (Continued)Specifications with standard type face are for TJ = 25˚C, and those with boldface type apply over full Operating Temperature Range.

Unless otherwise specified, VIN = 12V for the 3.3V, 5V, and Adjustable version and VIN = 24V for the 12V version. ILOAD = 500 mALM2596-XXSymbolIHParameterConditionsON /OFF Pin Input CurrentILTyp(Note 3)VLOGIC = 2.5V (Regulator OFF)Limit(Note 4)5VLOGIC = 0.5V (Regulator ON)Units(Limits)µA15µA(max)5µA(max)0.02µANote 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for which the device isintended to be functional, but do not guarantee specific performance limits. For guaranteed specifications and test conditions, see the Electrical Characteristics.Note 2: The human body model is a 100 pF capacitor discharged through a 1.5k resistor into each pin.Note 3: Typical numbers are at 25˚C and represent the most likely norm.Note 4: All limits guaranteed at room temperature (standard type face) and at temperature extremes (bold type face).

All room temperature limits are 100%production tested. All limits at temperature extremes are guaranteed via correlation using standard Statistical Quality Control (SQC) methods. All limits are used tocalculate Average Outgoing Quality Level (AOQL).Note 5: External components such as the catch diode, inductor, input and output capacitors, and voltage programming resistors can affect switching regulatorsystem performance. When the LM2596 is used as shown in the Figure 1 test circuit, system performance will be as shown in system parameters section of ElectricalCharacteristics.Note 6: The switching frequency is reduced when the second stage current limit is activated.Note 7: No diode, inductor or capacitor connected to output pin.Note 8: Feedback pin removed from output and connected to 0V to force the output transistor switch ON.Note 9: Feedback pin removed from output and connected to 12V for the 3.3V, 5V, and the ADJ.

version, and 15V for the 12V version, to force the output transistorswitch OFF.Note 10: VIN = 40V.Note 11: Junction to ambient thermal resistance (no external heat sink) for the TO-220 package mounted vertically, with the leads soldered to a printed circuit boardwith (1 oz.) copper area of approximately 1 in2.Note 12: Junction to ambient thermal resistance with the TO-263 package tab soldered to a single printed circuit board with 0.5 in2 of (1 oz.) copper area.Note 13: Junction to ambient thermal resistance with the TO-263 package tab soldered to a single sided printed circuit board with 2.5 in2 of (1 oz.) copper area.Note 14: Junction to ambient thermal resistance with the TO-263 package tab soldered to a double sided printed circuit board with 3 in2 of (1 oz.) copper area onthe LM2596S side of the board, and approximately 16 in2 of copper on the other side of the p-c board.