ZHCSFE2A August 2016 – November 2017 LM5161-Q1
PRODUCTION DATA.
- 1 特性
- 2 應用
- 3 說明
- 4 修訂歷史記錄
- 5 Pin Configuration and Functions
- 6 Specifications
-
7 Detailed Description
- 7.1 Overview
- 7.2 Functional Block Diagram
- 7.3
Feature Description
- 7.3.1 Control Circuit
- 7.3.2 VCC Regulator
- 7.3.3 Regulation Comparator
- 7.3.4 Soft-Start
- 7.3.5 Error Transconductance (GM) Amplifier
- 7.3.6 On-Time Generator
- 7.3.7 Current Limit
- 7.3.8 N-Channel Buck Switch and Driver
- 7.3.9 Synchronous Rectifier
- 7.3.10 Enable / Undervoltage Lockout (EN/UVLO)
- 7.3.11 Thermal Protection
- 7.3.12 Ripple Configuration
- 7.4 Device Functional Modes
-
8 Applications and Implementation
- 8.1 Application Information
- 8.2
Typical Applications
- 8.2.1
LM5161-Q1 Synchronous Buck (15-V to 95-V Input, 12-V Output, 1-A Load)
- 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 Output Resistor Divider Selection
- 8.2.1.2.3 Frequency Selection
- 8.2.1.2.4 Inductor Selection
- 8.2.1.2.5 Output Capacitor Selection
- 8.2.1.2.6 Series Ripple Resistor - RESR (FPWM = 1)
- 8.2.1.2.7 VCC and Bootstrap Capacitor
- 8.2.1.2.8 Input Capacitor Selection
- 8.2.1.2.9 Soft-Start Capacitor Selection
- 8.2.1.2.10 EN/UVLO Resistor Selection
- 8.2.1.3 Application Curves
- 8.2.2 LM5161-Q1 Isolated Fly-Buck (36-V to 72-V Input, 12-V, 12-W Isolated Output)
- 8.2.1
LM5161-Q1 Synchronous Buck (15-V to 95-V Input, 12-V Output, 1-A Load)
- 8.3 Do's and Don'ts
- 9 Power Supply Recommendations
- 10Layout
- 11器件和文檔支持
- 12機械、封裝和可訂購信息
8.2.1.2.5 Output Capacitor Selection
The output capacitor is selected to limit the capacitive ripple at the output of the regulator. Maximum capacitive ripple is observed at maximum input voltage. The output capacitance required for a ripple voltage ?VO across the capacitor is given by Equation 16.
Equation 16. 
Substituting ?VO, ripple = 10 mV gives COUT = 15 μF. Two standard 10 μF ceramic capacitors in parallel (C11, C12) are selected. An X7R type capacitor with a voltage rating 25 V or higher should be used for COUT (C11, C12) to limit the reduction of capacitance due to dc bias voltage.