LM5157
6A/4A, 50-V, 2.2-MHz wide VIN boost, flyback, & SEPIC converter with dual random spread spectrum
LM5157
- Suited for wide operating range for 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 (I Q ≤ 2.6 µA)
- Low operating current (I Q ≤ 670 µA)
- Small solution size and low cost
- Maximum switching frequency up to 2.2 MHz
- 16-pin QFN package (3 mm × 3 mm)
- Integrated error amplifier allows primary-side regulation without optocoupler (flyback)
- 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 R DSON 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 with the WEBENCH Power Designer
The LM5157 device is a wide input range, non-synchronous boost converter with integrated 50-V 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 an input supply voltage as low as 1.5 V if the BIAS pin is greater than 2.9 V.
The BIAS pin operates up to 45 V (50-V absolute maximum). The switching frequency is dynamically programmable with an external resistor from 100 kHz to 2.2 MHz. Switching at 2.2 MHz minimizes AM band interference and allows for a small solution size and fast transient response. To reduce the EMI of the power supply, the device provides a selectable Dual Random Spread Spectrum, which reduces the EMI over a wide frequency range.
The device features an accurate peak current limit over the input voltage, which avoids overdesigning power inductor. Low operating current and pulse-skipping operation improve efficiency at light loads.
The device has built-in protection features such as overvoltage protection, line UVLO, thermal shutdown, and selectable Hiccup mode overload protection. Additional features include low shutdown I Q, programmable soft start, precision reference, a power-good indicator, and external clock synchronization.
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Technical documentation
Type | Title | Date | ||
---|---|---|---|---|
* | Data sheet | LM5157 2.2-MHz Wide VIN 50-V Boost/SEPIC/Flyback Converter with Dual Random Spread Spectrum datasheet (Rev. A) | PDF | HTML | 03 May 2023 |
Application note | How to Implement the Soft Start in a Flyback | PDF | HTML | 10 Jul 2023 | |
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 | LM5157x, LM5158x를 사용하여 부스트 컨버터를 설계하는 방법 | PDF | HTML | 28 Oct 2022 | |
User guide | LM5157 SEPIC Evaluation Module | PDF | HTML | 07 Mar 2022 | |
Certificate | LM5157EVM-SEPIC EU RoHS Declaration of Conformity (DoC) | 23 Dec 2021 | ||
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 | PDF | HTML | 18 Mar 2021 |
Design & development
For additional terms or required resources, click any title below to view the detail page where available.
LM5157EVM-BST — LM5157 boost converter evaluation module
LM5157EVM-FLY — LM5157 flyback boost converter evaluation module
LM5157EVM-SEPIC — LM5157 evaluation module for SEPIC
The LM5157EVM-SEPIC evaluation module showcases the features and performance of the LM5157 as wide input non-synchronous SEPIC converter. The standard configuration is designed to provide a regulated output of 12 V at up to 1 A from an input of 4 V to 32 V, switching at 2.1 MHz.
LM5157x-Q1 Encrypted PSpice Transient Model (Rev. B)
SNVR511 — LM5157 and LM5158 Quickstart Calculator for Boost Regulator Design
Supported products & hardware
Products
AC/DC & DC/DC converters (integrated FET)
SNVR512 — LM5157 and LM5158 Quickstart Calculator for SEPIC Regulator Design
Supported products & hardware
Products
AC/DC & DC/DC converters (integrated FET)
Package | Pins | CAD symbols, footprints & 3D models |
---|---|---|
WQFN (RTE) | 16 | Ultra Librarian |
Ordering & quality
- RoHS
- REACH
- Device marking
- Lead finish/Ball material
- MSL rating/Peak reflow
- MTBF/FIT estimates
- Material content
- Qualification summary
- Ongoing reliability monitoring
- Fab location
- Assembly location
Support & training
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