SNVSBK7
July 2021
LM5157
PRODUCTION DATA
1
Features
2
Applications
3
Description
4
Revision History
5
Device Comparison Table
6
Pin Configuration and Functions
7
Specifications
7.1
Absolute Maximum Ratings
7.2
ESD Ratings
7.3
Recommended Operating Conditions
7.4
Thermal Information
7.5
Electrical Characteristics
7.6
Typical Characteristics
8
Detailed Description
8.1
Overview
8.2
Functional Block Diagram
8.3
Feature Description
8.3.1
Line Undervoltage Lockout (UVLO/SYNC/EN Pin)
8.3.2
High Voltage VCC Regulator (BIAS, VCC Pin)
8.3.3
Soft Start (SS Pin)
8.3.4
Switching Frequency (RT Pin)
8.3.5
Dual Random Spread Spectrum – DRSS (MODE Pin)
8.3.6
Clock Synchronization (UVLO/SYNC/EN Pin)
8.3.7
Current Sense and Slope Compensation
8.3.8
Current Limit and Minimum On Time
8.3.9
Feedback and Error Amplifier (FB, COMP Pin)
8.3.10
Power-Good Indicator (PGOOD Pin)
8.3.11
Hiccup Mode Overload Protection (MODE Pin)
8.3.12
Maximum Duty Cycle Limit and Minimum Input Supply Voltage
8.3.13
Internal MOSFET (SW Pin)
8.3.14
Overvoltage Protection (OVP)
8.3.15
Thermal Shutdown (TSD)
8.4
Device Functional Modes
8.4.1
Shutdown Mode
8.4.2
Standby Mode
8.4.3
Run Mode
8.4.3.1
Spread Spectrum Enabled
8.4.3.2
Hiccup Mode Protection Enabled
9
Application and Implementation
9.1
Application Information
9.2
Typical Application
9.2.1
Design Requirements
9.2.2
Detailed Design Procedure
9.2.2.1
Custom Design With WEBENCH® Tools
9.2.2.2
Recommended Components
9.2.2.3
Inductor Selection (LM)
9.2.2.4
Output Capacitor (COUT)
9.2.2.5
Input Capacitor
9.2.2.6
Diode Selection
9.2.3
Application Curve
9.3
System Examples
10
Power Supply Recommendations
11
Layout
11.1
Layout Guidelines
11.2
Layout Examples
12
Device and Documentation Support
12.1
Device Support
12.1.1
Third-Party Products Disclaimer
12.1.2
Development Support
12.1.2.1
Custom Design With WEBENCH® Tools
12.1.3
Export Control Notice
12.2
Documentation Support
12.2.1
Related Documentation
12.3
Receiving Notification of Documentation Updates
12.4
Support Resources
12.5
Trademarks
12.6
Electrostatic Discharge Caution
12.7
Glossary
13
Mechanical, Packaging, and Orderable Information
Package Options
Mechanical Data (Package|Pins)
RTE|16
MPQF149D
Thermal pad, mechanical data (Package|Pins)
RTE|16
QFND525B
Orderable Information
snvsbk7_oa
snvsbk7_pm
1
Features
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