LM2577

ACTIVE

3.5-V to 40-V, 3-A low component count step-up regulator

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LM5157 ACTIVE 6A/4A, 50-V, 2.2-MHz wide VIN boost, flyback, & SEPIC converter with dual random spread spectrum Integrated, 6-A 50-V wide-input range.

Product details

Rating Catalog Operating temperature range (°C) -40 to 125 Topology Boost, Flyback, Forward, SEPIC Type Converter Vin (min) (V) 3.5 Vin (max) (V) 40 Switching frequency (min) (kHz) 52 Switching frequency (max) (kHz) 52 Features Nonsynchronous rectification, UVLO Fixed Vout (min) (V) 1.23 Vout (max) (V) 60 Iq (typ) (µA) 10000 Duty cycle (max) (%) 95 Switch current limit (typ) (A) 3
Rating Catalog Operating temperature range (°C) -40 to 125 Topology Boost, Flyback, Forward, SEPIC Type Converter Vin (min) (V) 3.5 Vin (max) (V) 40 Switching frequency (min) (kHz) 52 Switching frequency (max) (kHz) 52 Features Nonsynchronous rectification, UVLO Fixed Vout (min) (V) 1.23 Vout (max) (V) 60 Iq (typ) (µA) 10000 Duty cycle (max) (%) 95 Switch current limit (typ) (A) 3
TO-220 (KC) 5 45.212 mm² 10.16 x 4.45 TO-220 (NDH) 5 86.0552 mm² 10.16 x 8.47 TO-263 (KTT) 5 154.8384 mm² 10.16 x 15.24
  • Requires Few External Components
  • NPN Output Switches 3.0A, can Stand off 65V
  • Wide Input Voltage Range: 3.5V to 40V
  • Current-mode Operation for Improved Transient Response, Line Regulation, and Current Limit
  • 52 kHz Internal Oscillator
  • Soft-start Function Reduces In-rush Current During Start-up
  • Output Switch Protected by Current Limit, Under-voltage Lockout, and Thermal Shutdown

All trademarks are the property of their respective owners.

  • Requires Few External Components
  • NPN Output Switches 3.0A, can Stand off 65V
  • Wide Input Voltage Range: 3.5V to 40V
  • Current-mode Operation for Improved Transient Response, Line Regulation, and Current Limit
  • 52 kHz Internal Oscillator
  • Soft-start Function Reduces In-rush Current During Start-up
  • Output Switch Protected by Current Limit, Under-voltage Lockout, and Thermal Shutdown

All trademarks are the property of their respective owners.

The LM1577/LM2577 are monolithic integrated circuits that provide all of the power and control functions for step-up (boost), flyback, and forward converter switching regulators. The device is available in three different output voltage versions: 12V, 15V, and adjustable.

Requiring a minimum number of external components, these regulators are cost effective, and simple to use. Listed in this data sheet are a family of standard inductors and flyback transformers designed to work with these switching regulators.

Included on the chip is a 3.0A NPN switch and its associated protection circuitry, consisting of current and thermal limiting, and undervoltage lockout. Other features include a 52 kHz fixed-frequency oscillator that requires no external components, a soft start mode to reduce in-rush current during start-up, and current mode control for improved rejection of input voltage and output load transients.

The LM1577/LM2577 are monolithic integrated circuits that provide all of the power and control functions for step-up (boost), flyback, and forward converter switching regulators. The device is available in three different output voltage versions: 12V, 15V, and adjustable.

Requiring a minimum number of external components, these regulators are cost effective, and simple to use. Listed in this data sheet are a family of standard inductors and flyback transformers designed to work with these switching regulators.

Included on the chip is a 3.0A NPN switch and its associated protection circuitry, consisting of current and thermal limiting, and undervoltage lockout. Other features include a 52 kHz fixed-frequency oscillator that requires no external components, a soft start mode to reduce in-rush current during start-up, and current mode control for improved rejection of input voltage and output load transients.

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Technical documentation

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Type Title Date
* Data sheet LM1577/LM2577 SIMPLE SWITCHER Step-Up Voltage Regulator datasheet (Rev. D) 03 Apr 2013
Application note Semiconductor and IC Package Thermal Metrics (Rev. D) PDF | HTML 25 Mar 2024
Application note 스트컨버터의 전력계 기본 계산 (Rev. D) PDF | HTML 21 Nov 2022
Application note Basic Calculation of a Boost Converter's Power Stage (Rev. D) PDF | HTML 28 Oct 2022
Application note Switching regulator fundamentals (Rev. C) PDF | HTML 05 Feb 2019
Application note Working With Boost Converters 15 Jun 2015
Application note AN-2162 Simple Success With Conducted EMI From DC-DC Converters (Rev. C) 24 Apr 2013
Application note AN-1149 Layout Guidelines for Switching Power Supplies (Rev. C) 23 Apr 2013
Application note AN-1229 SIMPLE SWITCHER PCB Layout Guidelines (Rev. C) 23 Apr 2013
Application note AN-1520 A Guide to Board Layout for Best Thermal Resistance for Exposed Packages (Rev. B) 23 Apr 2013
Application note AN-1566 Techniques for Thermal Analysis of Switching Power Supply Designs (Rev. A) 23 Apr 2013
Application note AN-1889 How to Measure the Loop Transfer Function of Power Supplies (Rev. A) 23 Apr 2013
Application note AN-2155 Layout Tips for EMI Reduction in DC/ DC Converters (Rev. A) 23 Apr 2013
Application note AN-776 20-W SIMPLE SWITCHER Forward Converter (Rev. A) 23 Apr 2013
Application note AN-777 LM2577 Three Output, Isolated Flyback Regulator (Rev. B) 23 Apr 2013
Application note Negative Buck Switching Regulator (using LM258x) 21 Mar 2007
Application note Input and Output Capacitor Selection 19 Sep 2005
More literature SEM1600 Topic 4: Constructing Your Power Supply – Layout Considerations 12 Jul 2005
Application note AN-643 EMI/RFI Board Design (Rev. B) 03 May 2004
Application note Understanding Boost Power Stages In Switchmode Power Supplies 04 Mar 1999

Design & development

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Support software

SWITCHERSMADESIMPLE-SW Switchers Made Simple® Software

Note: The Switchers Made Simple design computations have been incorporated into Texas Instruments' award winning WEBENCH Power Designer Online Design Tool. Please use TI's WEBENCH Power Designer online tools for new designs. The WEBENCH Design Tool also includes:

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Supported products & hardware

Supported products & hardware

Products
AC/DC & DC/DC converters (integrated FET)
LM2574 8V to 40V, 500mA SIMPLE SWITCHER® buck converter with 4 external components LM2575 1-A Simple Step-Down Adjustable Voltage Switching Regulator with Output Enable LM2576 SIMPLE SWITCHER® 40V, 3A Low Component Count Step-Down Regulator LM2577 3.5-V to 40-V, 3-A low component count step-up regulator
Calculation tool

FLYBUCK-FLYBACK-DESIGN-CALC Flybuck / Flyback Calculator

This tool helps a power supply engineer to select the right isolated DC-DC topology based on the specifications. Depending on the topology chosen, the calculator also recommends the right IC for the design.

Supported products & hardware

Supported products & hardware

Products
AC/DC & DC/DC controllers (external FET)
LM3017 High Efficiency Low-Side Controller with True Shutdown LM3478 2.97~40V Wide Input Range Boost/SEPIC/Flyback DC-DC Controller LM3478Q-Q1 40-V wide VIN low-side N-channel controller for switching regulators with 10-µA shutdown current LM3481 2.97V to 48V High-Efficiency Controller for Boost, SEPIC and Flyback LM3481-Q1 2.97-V to 48-V high-efficiency controller for boost, SEPIC and flyback, AEC-Q100 qualified LM3488 2.97V to 40V Wide Vin Low-Side N-Channel Controller for Switching Regulators LM3488Q-Q1 40-V wide VIN low-side N-channel controller for switching regulators with 5-µA shutdown current LM3524D 40V, 0.2A 350KHz PWM controller LM3578A 2-V to 40-VIN switching regulators in buck, boost, terminal, depending upon the application LM5020 13-100V Wide Vin, Current Mode PWM Boost, Flyback, Sepic Controller LM5022 6-60V Wide Vin, current mode boost, SEPIC and Flyback controller TL1451 Dual Pulse-Width-Modulation Control Circuit TL1451A 3.6V to 50V dual channel controller with Wide input voltage range TL1451A-EP Enhanced Product Dual Pulse-Width-Modulation Control Circuits TL1451A-Q1 3.6-V to 50-V dual-channel PWM controller, AEC-Q100 qualified TL5001 PWM Controller with wide input range, with ±5% tolerance on reference, operation –20°C to 85°C TL5001A PWM Controller with wide input range, with ±3% tolerance on reference, operation –20°C to 85°C TL5001A-Q1 PWM Controller with wide input range, with ±3% tolerance on reference, operation –20°C to 85°C TL5001M PWM Controller with wide input range, with ±5% tolerance on reference, operation –55°C to 125°C TPS40210-Q1 4.5-V to 52-V wide input range current mode boost controller with 700-mV reference voltage TPS40211-Q1 4.5-V to 52-V wide input range current mode boost controller with 260-mV reference voltage TPS43000 Multi-Topology (buck, boost, sepic) High Frequency DC/DC Controller TPS55010 2.95V To 6V Input, 2W, Isolated DC/DC Converter with Integrated FETS UC2572 Negative output Flyback pulse width modulator
AC/DC & DC/DC converters (integrated FET)
LM25017 7.5-48V Wide Vin, 650mA Constant On-Time Synchronous Buck Regulator LM25018 7.5-48V Wide Vin, 300mA Constant On-Time Synchronous Buck Regulator LM25019 7.5-48V Wide Vin, 100mA Constant On-Time Synchronous Buck Regulator LM2577 3.5-V to 40-V, 3-A low component count step-up regulator LM2585 4-V to 40-V, 3-A step-up wide VIN flyback regulator LM2586 4-V to 40-V, 3-A step-up wide VIN flyback regulator with frequency synchronization LM2587 4V to 40V, 5A Step-Up Wide Vin Flyback Regulator LM2588 4-V to 40-V, 5-A step-up wide VIN flyback regulator with frequency synchronization LM2621 1.2V to 14V input voltage, 1A load current, step-up DC-DC LM2623 0.8V to 14V input voltage, 2A load current, step-up DC-DC LM2623-Q1 0.8-V to 14-V input voltage, 2-A load current, step-up DC/DC, AEC-Q100 qualified LM2735 520kHz/1.6MHz space efficient boost and SEPIC DC-DC regulator LM2735-Q1 520-kHz, 1.6-MHz space efficient boost and SEPIC DC/DC regulator, AEC-Q100 qualified LM34925 7.5-100V Wide Vin, 100mA Integrated Secondary Bias Regulator for Isolated DC/DC Converters LM34926 7.5-100V Wide Vin, 300mA Integrated Secondary Bias Regulator for Isolated DC/DC Converters LM34927 7.5-100V Wide Vin, 600mA Integrated Secondary Bias Regulator for Isolated DC/DC Converters LM5000 3.1-40V Wide Vin, 2A Current Mode Non-Synchronous Boost Regulator LM5001 3.1-75V Wide Vin, 1A Current Mode Non-Synchronous Switch Mode Regulator LM5001-Q1 3.1-V to 75-V wide VIN, 1-A current mode non-synchronous switch mode regulator LM5002 3.1-75V Wide Vin, 0.5A Current Mode Boost, Flyback, Sepic Converter LM5015 4.25-75V, Monolithic Two-Switch Forward DC-DC Regulator LM5017 7.5-100V Wide Vin, 600mA Constant On-Time Synchronous Buck Regulator LM5018 7.5-100V Wide Vin, 300mA Constant On-Time Synchronous Buck Regulator LM5019 7.5-100V Wide Vin, 100mA Constant On-Time Synchronous Buck Regulator LM5160 LM5160 wide input 65V, 2A synchronous buck/Fly-Buck™ converter LM5160-Q1 Wide Input 65V, 2A Synchronous Buck / Fly-Buck™ Converter LM5160A LM5160A Wide Input 65V, 2A Synchronous Buck / Fly-Buck™ Converter LM5161 Wide Input 4.5-V to 100-V, 1-A Synchronous Buck / Fly-Buck Converter LM78S40 1.5A Adjustable Step Up, Step Down or Inverting Regulator TPS55340 5-A, 40-V, wide VIN boost, flyback, & SEPIC converter TPS55340-EP Enhanced integrated, 5-A, 40-V wide input range boost/SEPIC/flyback DC/DC regulator TPS55340-Q1 Integrated, 5-A 40-V wide input range boost/SEPIC/flyback DC/DC regulator, AEC-Q100 qualified TPS61175 3-A ,40V High Voltage Boost Converter with Soft-start and Programmable Switching Frequency TPS61175-Q1 3-A, 40-V high voltage boost converter with soft-start and programmable switching frequency
Package Pins CAD symbols, footprints & 3D models
TO-220 (KC) 5 Ultra Librarian
TO-220 (NDH) 5 Ultra Librarian
TO-263 (KTT) 5 Ultra Librarian

Ordering & quality

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Information included:
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