ZHCSL48 April 2020 LM5181-Q1
PRODUCTION DATA.
- 1 特性
- 2 应用
- 3 说明
- 4 修订历史记录
- 5 说明 （续）
- 6 Pin Configuration and Functions
- 7 Specifications
-
8 Detailed Description
- 8.1 Overview
- 8.2 Functional Block Diagram
- 8.3
Feature Description
- 8.3.1 Integrated Power MOSFET
- 8.3.2 PSR Flyback Modes of Operation
- 8.3.3 Setting the Output Voltage
- 8.3.4 Control Loop Error Amplifier
- 8.3.5 Precision Enable
- 8.3.6 Configurable Soft Start
- 8.3.7 External Bias Supply
- 8.3.8 Minimum On-Time and Off-Time
- 8.3.9 Overcurrent Protection
- 8.3.10 Thermal Shutdown
- 8.4 Device Functional Modes
-
9 Application and Implementation
- 9.1 Application Information
- 9.2
Typical Applications
- 9.2.1
Design 1: Wide VIN, Low IQ PSR Flyback Converter Rated at 5 V, 0.5 A
- 9.2.1.1 Design Requirements
- 9.2.1.2
Detailed Design Procedure
- 9.2.1.2.1 Custom Design With WEBENCH® Tools
- 9.2.1.2.2 Custom Design With Excel Quickstart Tool
- 9.2.1.2.3 Flyback Transformer – T1
- 9.2.1.2.4 Flyback Diode – DFLY
- 9.2.1.2.5 Zener Clamp Circuit – DF, DCLAMP
- 9.2.1.2.6 Output Capacitor – COUT
- 9.2.1.2.7 Input Capacitor – CIN
- 9.2.1.2.8 Feedback Resistor – RFB
- 9.2.1.2.9 Thermal Compensation Resistor – RTC
- 9.2.1.2.10 UVLO Resistors – RUV1, RUV2
- 9.2.1.2.11 Soft-Start Capacitor – CSS
- 9.2.2 Application Curves
- 9.2.1
Design 1: Wide VIN, Low IQ PSR Flyback Converter Rated at 5 V, 0.5 A
- 10Power Supply Recommendations
- 11Layout
- 12器件和文档支持
- 13机械、封装和可订购信息
8.3.3 Setting the Output Voltage
To minimize output voltage regulation error, the LM5181-Q1 senses the reflected secondary voltage when the secondary current reaches zero. The feedback (FB) resistor, which is connected between SW and FB as shown in Figure 17, is determined using Equation 8.
Equation 8. 
where
- RSET is nominally 12.1 kΩ