Menu
Product
Email
PDF
Order now
LM5157x-Q1 2.2-MHz Wide VIN 50-V Boost/SEPIC/Flyback Converter with Dual Random Spread Spectrum
SNVSBK8B
october 2020 – august 2023
LM5157-Q1
,
LM51571-Q1
PRODUCTION DATA
CONTENTS
SEARCH
LM5157x-Q1 2.2-MHz Wide VIN 50-V Boost/SEPIC/Flyback Converter with Dual Random Spread Spectrum
1
1
Features
2
Applications
3
Description
4
Revision History
5
Description (continued)
6
Device Comparison Table
7
Pin Configuration and Functions
8
Specifications
8.1
Absolute Maximum Ratings
8.2
ESD Ratings
8.3
Recommended Operating Conditions
8.4
Thermal Information
8.5
Electrical Characteristics
8.6
Typical Characteristics
9
Detailed Description
9.1
Overview
9.2
Functional Block Diagram
9.3
Feature Description
9.3.1
Line Undervoltage Lockout (UVLO/SYNC/EN Pin)
9.3.2
High Voltage VCC Regulator (BIAS, VCC Pin)
9.3.3
Soft Start (SS Pin)
9.3.4
Switching Frequency (RT Pin)
9.3.5
Dual Random Spread Spectrum – DRSS (MODE Pin)
9.3.6
Clock Synchronization (UVLO/SYNC/EN Pin)
9.3.7
Current Sense and Slope Compensation
9.3.8
Current Limit and Minimum On Time
9.3.9
Feedback and Error Amplifier (FB, COMP Pin)
9.3.10
Power-Good Indicator (PGOOD Pin)
9.3.11
Hiccup Mode Overload Protection (MODE Pin)
9.3.12
Maximum Duty Cycle Limit and Minimum Input Supply Voltage
9.3.13
Internal MOSFET (SW Pin)
9.3.14
Overvoltage Protection (OVP)
9.3.15
Thermal Shutdown (TSD)
9.4
Device Functional Modes
9.4.1
Shutdown Mode
9.4.2
Standby Mode
9.4.3
Run Mode
9.4.3.1
Spread Spectrum Enabled
9.4.3.2
Hiccup Mode Protection Enabled
10
Application and Implementation
10.1
Application Information
10.2
Typical Application
10.2.1
Design Requirements
10.2.2
Detailed Design Procedure
10.2.2.1
Custom Design With WEBENCH® Tools
10.2.2.2
Recommended Components
10.2.2.3
Inductor Selection (LM)
10.2.2.4
Output Capacitor (COUT)
10.2.2.5
Input Capacitor
10.2.2.6
Diode Selection
10.2.3
Application Curve
10.3
System Examples
11
Power Supply Recommendations
12
Layout
12.1
Layout Guidelines
12.2
Layout Examples
13
Device and Documentation Support
13.1
Device Support
13.1.1
Third-Party Products Disclaimer
13.1.2
Development Support
13.1.2.1
Custom Design With WEBENCH® Tools
13.1.3
Export Control Notice
13.2
Documentation Support
13.2.1
Related Documentation
13.3
Receiving Notification of Documentation Updates
13.4
Support Resources
13.5
Trademarks
13.6
Electrostatic Discharge Caution
13.7
Glossary
14
Mechanical, Packaging, and Orderable Information
IMPORTANT NOTICE
Package Options
Mechanical Data (Package|Pins)
RTE|16
MPQF149D
Thermal pad, mechanical data (Package|Pins)
RTE|16
QFND630A
Orderable Information
snvsbk8b_oa
snvsbk8b_pm
search
No matches found.
Full reading width
Full reading width
Comfortable reading width
Expanded reading width
Card for each section
Card with all content
Data Sheet
LM5157x-Q1
2.2-MHz Wide V
IN
50-V Boost/SEPIC/Flyback Converter with Dual Random Spread Spectrum
1
Features
AEC-Q100 qualified for automotive applications
Temperature grade 1: –40°C to +125°C T
A
Functional Safety-Capable
Documentation available to aid functional safety system design
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 (I
Q
≤ 2.6 µA)
Low operating current (I
Q
≤ 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 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-Q1 with the
WEBENCH®
Power Designer
2
Applications
Battery-powered wide input boost, SEPIC, flyback converter
Automotive voltage stabilizer in SEPIC
Automotive start-stop application
Automotive emergency call application/backup battery booster
High voltage LiDAR power supply
Automotive LED bias supply
Multiple-output flyback without optocoupler
Holdup capacitor charger
Audio amplifier power supply
Piezo driver/motor driver bias supply