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Boost converters (integrated switch)

LM51571-Q1

ACTIVE

4-A, 50-V, 2.2-MHz wide VIN boost, flyback, & SEPIC converter with dual random spread spectrum

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Data sheet

LM51571-Q1

ACTIVE
Data sheet Order now

Product details

Topology Boost, Flyback, SEPIC Vin (min) (V) 1.5 Vin (max) (V) 45 Vout (min) (V) 2 Vout (max) (V) 48 Switch current limit (typ) (A) 5 Type Converter Regulated outputs (#) 1 Switching frequency (min) (kHz) 100 Switching frequency (max) (kHz) 2200 Iq (typ) (mA) 0.67 Features Enable, Frequency synchronization, Light Load Efficiency, Nonsynchronous rectification, Power good, Spread Spectrum, UVLO adjustable TI functional safety category Functional Safety-Capable Duty cycle (max) (%) 93 Operating temperature range (°C) -40 to 150 Rating Automotive
Topology Boost, Flyback, SEPIC Vin (min) (V) 1.5 Vin (max) (V) 45 Vout (min) (V) 2 Vout (max) (V) 48 Switch current limit (typ) (A) 5 Type Converter Regulated outputs (#) 1 Switching frequency (min) (kHz) 100 Switching frequency (max) (kHz) 2200 Iq (typ) (mA) 0.67 Features Enable, Frequency synchronization, Light Load Efficiency, Nonsynchronous rectification, Power good, Spread Spectrum, UVLO adjustable TI functional safety category Functional Safety-Capable Duty cycle (max) (%) 93 Operating temperature range (°C) -40 to 150 Rating Automotive
WQFN (RTE) 16 9 mm² 3 x 3
  • AEC-Q100 qualified for automotive applications
    • Temperature grade 1: –40°C to +125°C TA
  • Functional Safety-Capable
  • Suited for wide operating range for car battery applications
    • 2.9-V to 45-V input operating range
    • 48-V maximum output (50-V abs max)
    • Minimum boost supply voltage of 1.5 V when BIAS ≥ 2.9 V
    • Input transient protection up to 50 V
    • Minimized battery drain
      • Low shutdown current (IQ ≤ 2.6 µA)
      • Low operating current (IQ ≤ 700 µA)
  • Small solution size and low cost
    • Maximum switching frequency up to 2.2 MHz
    • 16-pin QFN package (3 mm × 3 mm) with wettable flanks
    • Integrated error amplifier allows primary-side regulation without optocoupler (flyback)
    • Minimized undershoot during cranking (start-stop application)
    • Accurate current limit (see the Device Comparison Table)
  • EMI mitigation
    • Selectable dual random spread spectrum
    • Lead-less package
  • Higher efficiency with low-power dissipation
    • 45-mΩ RDSON switch
    • Fast switching, small switching loss
  • Avoid AM band interference and crosstalk
    • Optional clock synchronization
    • Dynamically programmable wide switching frequency from 100 kHz to 2.2 MHz
  • Integrated protection features
    • Constant current limiting over input voltage
    • Selectable hiccup mode overload protection
    • Programmable line UVLO
    • OVP protection
    • Thermal shutdown
  • Accurate ±1% accuracy feedback reference
  • Adjustable soft start
  • PGOOD indicator
  • Create a custom design using the LM5157x-Q1 with the WEBENCH Power Designer
  • AEC-Q100 qualified for automotive applications
    • Temperature grade 1: –40°C to +125°C TA
  • Functional Safety-Capable
  • Suited for wide operating range for car battery applications
    • 2.9-V to 45-V input operating range
    • 48-V maximum output (50-V abs max)
    • Minimum boost supply voltage of 1.5 V when BIAS ≥ 2.9 V
    • Input transient protection up to 50 V
    • Minimized battery drain
      • Low shutdown current (IQ ≤ 2.6 µA)
      • Low operating current (IQ ≤ 700 µA)
  • Small solution size and low cost
    • Maximum switching frequency up to 2.2 MHz
    • 16-pin QFN package (3 mm × 3 mm) with wettable flanks
    • Integrated error amplifier allows primary-side regulation without optocoupler (flyback)
    • Minimized undershoot during cranking (start-stop application)
    • Accurate current limit (see the Device Comparison Table)
  • EMI mitigation
    • Selectable dual random spread spectrum
    • Lead-less package
  • Higher efficiency with low-power dissipation
    • 45-mΩ RDSON switch
    • Fast switching, small switching loss
  • Avoid AM band interference and crosstalk
    • Optional clock synchronization
    • Dynamically programmable wide switching frequency from 100 kHz to 2.2 MHz
  • Integrated protection features
    • Constant current limiting over input voltage
    • Selectable hiccup mode overload protection
    • Programmable line UVLO
    • OVP protection
    • Thermal shutdown
  • Accurate ±1% accuracy feedback reference
  • Adjustable soft start
  • PGOOD indicator
  • Create a custom design using the LM5157x-Q1 with the WEBENCH Power Designer

The LM5157x-Q1 device is a wide input range, non-synchronous boost converter with integrated 50-V, 6.5-A (LM5157-Q1) or 50-V, 4.33-A (LM51571-Q1) power switch.

The device can be used in boost, SEPIC, and flyback topologies. The device can start up from a single-cell battery with a minimum of 2.9 V. It can operate with the input supply voltage as low as 1.5 V if the BIAS pin is greater than 2.9 V.

The LM5157x-Q1 device is a wide input range, non-synchronous boost converter with integrated 50-V, 6.5-A (LM5157-Q1) or 50-V, 4.33-A (LM51571-Q1) power switch.

The device can be used in boost, SEPIC, and flyback topologies. The device can start up from a single-cell battery with a minimum of 2.9 V. It can operate with the input supply voltage as low as 1.5 V if the BIAS pin is greater than 2.9 V.
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LM5158-Q1 ACTIVE 3-A, 85-V, 2.2-MHz wide VIN boost, flyback, & SEPIC converter with dual random spread spectrum LM5158-Q1 has higher Vin, Vout capability

Technical documentation

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Type Title Date
* Data sheet LM5157x-Q1 2.2-MHz Wide VIN 50-V Boost/SEPIC/Flyback Converter with Dual Random Spread Spectrum datasheet (Rev. A) PDF | HTML 02 Mar 2021
Application note How to Design an Isolated Flyback Converter Using LM5157x/LM5158x (Rev. A) PDF | HTML 16 Mar 2023
Application note Basic Calculation of a Coupled Inductor SEPIC Power Stage PDF | HTML 13 Mar 2023
Application note EMI 감소 기법, 듀얼 랜덤 확산 스펙트럼 (Rev. A) PDF | HTML 21 Nov 2022
Application note LM5157x, LM5158x를 사용하여 부스트 컨버터를 설계하는 방법 PDF | HTML 28 Oct 2022
Application note EMI Reduction Technique, Dual Random Spread Spectrum (Rev. A) 19 Oct 2022
Functional safety information LM5157x-Q1 Functional Safety, FIT Rate, Failure Mode Distribution and Pin FMA (Rev. A) PDF | HTML 11 Feb 2022
Application note How to Design a Boost Converter Using LM5157x, LM5158x PDF | HTML 11 Nov 2021
EVM User's guide LM5157-Q1 Flyback Converter Evaluation Module PDF | HTML 04 May 2021
Technical article Lowering audible noise in automotive applications with TI’s DRSS technology 18 Mar 2021
Analog Design Journal The pros and cons of spread‐spectrum implementation methods in buck regulators 18 Mar 2021

Design & development

For additional terms or required resources, click any title below to view the detail page where available.

Evaluation board

LM5157EVM-BST — LM5157 boost converter evaluation module

The LM5157EVM-BST evaluation module showcases the features and performance of the LM5157 device as a wide input voltage boost converter with dual random spread spectrum. The standard configuration is designed to provide a regulated output of 12 V at 1.6 A from an input of 3 V to (...)
User guide: PDF | HTML
Not available on TI.com
Evaluation board

LM5157EVM-FLY — LM5157 flyback boost converter evaluation module

The LM5157EVM-FLY evaluation module showcases the features and performance of the LM5157 as a flyback converter to produce multiple output voltage rails for typical applications of the 3phase inverter gate driver bias supplies.  The standard configuration is designed to provide a regulated (...)
User guide: PDF | HTML
Not available on TI.com
Simulation model

LM5157x-Q1 Encrypted PSpice Transient Model (Rev. B)

SNVMC64B.ZIP (193 KB) - PSpice Model
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Simulation model

LM5157x-Q1 PSpice Average Model (Encrypted)

SNVMC63.ZIP (53 KB) - PSpice Model
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Calculation tool

LM515x Quickstart Calculator for Flyback Regulator Design

SNVR508.ZIP (6564 KB)
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Calculation tool

LM5157 and LM5158 Quickstart Calculator for Boost Regulator Design

SNVR511.ZIP (4066 KB)
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Calculation tool

LM5157 and LM5158 Quickstart Calculator for SEPIC Regulator Design (Rev. B)

SNVR512B.ZIP (1383 KB)
Download
Simulation tool

PSPICE-FOR-TI — PSpice® for TI design and simulation tool

PSpice® for TI is a design and simulation environment that helps evaluate functionality of analog circuits. This full-featured, design and simulation suite uses an analog analysis engine from Cadence®. Available at no cost, PSpice for TI includes one of the largest model libraries in the (...)
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