SNVSCL1
November 2023
LM25185
PRODUCTION DATA
1
1
Features
2
Applications
3
Description
4
Description (continued)
5
Pin Configuration and Functions
6
Specifications
6.1
Absolute Maximum Ratings
6.2
ESD Ratings
6.3
Recommended Operating Conditions
6.4
Thermal Information
6.5
Electrical Characteristics
6.6
Typical Characteristics
7
Detailed Description
7.1
Overview
7.2
Functional Block Diagram
7.3
Feature Description
7.3.1
Power MOSFET Gate Driver
7.3.2
PSR Flyback Modes of Operation
7.3.3
High Voltage VCC Regulator
7.3.4
Setting the Output Voltage
7.3.4.1
Diode Thermal Compensation
7.3.5
Control Loop Error Amplifier
7.3.6
Precision Enable
7.3.7
Configurable Soft Start
7.3.8
Minimum On-Time and Off-Time
7.3.9
Current Sensing and Overcurrent Protection
7.3.10
Thermal Shutdown
7.4
Device Functional Modes
7.4.1
Shutdown Mode
7.4.2
Standby Mode
7.4.3
Active Mode
8
Application and Implementation
8.1
Application Information
8.2
Typical Applications
8.2.1
Design 1: Wide VIN, Low IQ PSR Flyback Converter Rated at 16.4 V, 1 A
8.2.1.1
Design Requirements
8.2.1.2
Detailed Design Procedure
8.2.1.2.1
Custom Design With WEBENCH® Tools
8.2.1.2.2
Custom Design With Excel Quickstart Tool
8.2.1.2.3
Flyback Transformer T1 and Current-Sense Resistor (RCS)
8.2.1.2.4
Flyback Diode – DFLY
8.2.1.2.5
Leakage Inductance Clamp Circuit – DF, DCLAMP
8.2.1.2.6
Feedback Resistor – RFB
8.2.1.2.7
Thermal Compensation Resistor – RTC
8.2.1.2.8
UVLO Resistors – RUV1, RUV2
8.2.1.2.9
Soft-Start Capacitor – CSS
8.2.1.2.10
Compensation Components
8.2.1.3
Application Curves
8.3
Power Supply Recommendations
8.4
Layout
8.4.1
Layout Guidelines
8.4.2
Layout Examples
9
Device and Documentation Support
9.1
Device Support
9.1.1
Development Support
9.1.1.1
Custom Design With WEBENCH® Tools
9.2
Documentation Support
9.2.1
Related Documentation
9.3
Receiving Notification of Documentation Updates
9.4
Support Resources
9.5
Trademarks
9.6
Electrostatic Discharge Caution
9.7
Glossary
10
Revision History
11
Mechanical, Packaging, and Orderable Information
Package Options
Mechanical Data (Package|Pins)
PWP|14
MPDS370A
Thermal pad, mechanical data (Package|Pins)
PWP|14
PPTD022AA
Orderable Information
snvscl1_oa
snvscl1_pm
Data Sheet
LM25185
42
-V
IN
PSR Flyback DC/DC Controller With Low I
Q
and Low EMI