SNVSBL7A
March 2020 – August 2020
LM25184
PRODUCTION DATA
1
Features
2
Applications
3
Description
4
Revision History
5
Pin Configuration and Functions
Pin 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
Integrated Power MOSFET
7.3.2
PSR Flyback Modes of Operation
7.3.3
Setting the Output Voltage
7.3.3.1
Diode Thermal Compensation
7.3.4
Control Loop Error Amplifier
7.3.5
Precision Enable
7.3.6
Configurable Soft Start
7.3.7
External Bias Supply
7.3.8
Minimum On-Time and Off-Time
7.3.9
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 12 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
8.2.1.2.4
Flyback Diode – DFLY
8.2.1.2.5
Leakgae Inductance Clamp Circuit – DF, DCLAMP
8.2.1.2.6
Output Capacitor – COUT
8.2.1.2.7
Input Capacitor – CIN
8.2.1.2.8
Feedback Resistor – RFB
8.2.1.2.9
Thermal Compensation Resistor – RTC
8.2.1.2.10
UVLO Resistors – RUV1, RUV2
8.2.1.2.11
Soft-Start Capacitor – CSS
8.2.2
Application Curves
8.2.3
Design 2: PSR Flyback Converter With Dual Outputs of 15 V and –8 V at 0.5 A
8.2.3.1
Design Requirements
8.2.3.2
Detailed Design Procedure
8.2.3.2.1
Flyback Transformer – T1
8.2.3.2.2
Flyback Diodes – DFLY1 and DFLY2
8.2.3.2.3
Input Capacitor – CIN
8.2.3.2.4
Output Capacitors – COUT1, COUT2
8.2.3.2.5
Feedback Resistor – RFB
8.2.3.2.6
Thermal Compensation Resistor – RTC
8.2.3.2.7
Output Voltage Clamp Zeners – DOUT1 and DOUT2
8.2.3.3
Application Curves
9
Power Supply Recommendations
10
Layout
10.1
Layout Guidelines
10.2
Layout Examples
11
Device and Documentation Support
11.1
Device Support
11.1.1
Third-Party Products Disclaimer
11.1.2
Development Support
11.1.2.1
Custom Design With WEBENCH® Tools
11.2
Documentation Support
11.2.1
Related Documentation
11.3
Receiving Notification of Documentation Updates
11.4
Support Resources
11.5
Trademarks
11.6
Electrostatic Discharge Caution
11.7
Glossary
12
Mechanical, Packaging, and Orderable Information
Package Options
Mechanical Data (Package|Pins)
NGU|8
MPDS407A
Thermal pad, mechanical data (Package|Pins)
Orderable Information
snvsbl7a_oa
snvsbl7a_pm
1
Features
Functional Safety-Capable
Documentation available to aid functional safety system design
Designed for reliable and rugged applications
Wide input voltage range of 4.5 V to 42 V
with operation down to 3.5 V after start-up
Robust solution with only one component crossing the isolation barrier
±1.5% total output regulation accuracy
Optional V
OUT
temperature compensation
–40°C to +150°C junction temperature range
Integration reduces solution size and cost
Integrated 65-V, 0.11-Ω power MOSFET
No optocoupler or transformer auxiliary winding required for V
OUT
regulation
Internal loop compensation
High-efficiency PSR flyback operation
Quasi-resonant MOSFET turnoff in BCM
External bias option for improved efficiency
Single- and multi-output implementations
Ultra-low conducted and radiated EMI signatures
Soft switching avoids diode reverse recovery
Optimized for
CISPR 32
EMI requirements
Create a custom flyback regulator design using
WEBENCH®
Power Designer