SNVSAF9A
August 2016 – November 2017
LM5161-Q1
PRODUCTION DATA.
1
Features
2
Applications
3
Description
4
Revision History
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
Switching Characteristics
6.7
Typical Characteristics
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
7.4.1
Forced Pulse Width Modulation (FPWM) Mode
7.4.2
Undervoltage Detector
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)
8.2.2.1
LM5161-Q1 Fly-Buck Design Requirements
8.2.2.2
Detailed Design Procedure
8.2.2.2.1
Selection of VOUT and Turns Ratio
8.2.2.2.2
Secondary Rectifier Diode
8.2.2.2.3
External Ripple Circuit
8.2.2.2.4
Output Capacitor (CVISO)
8.2.2.3
Application Curves
8.3
Do's and Don'ts
9
Power Supply Recommendations
10
Layout
10.1
Layout Guidelines
10.2
Layout Example
11
Device and Documentation Support
11.1
Device Support
11.1.1
Development Support
11.1.1.1
Custom Design With WEBENCH® Tools
11.2
Related Documentation
11.3
Trademarks
11.4
Receiving Notification of Documentation Updates
11.5
Community Resources
11.6
Electrostatic Discharge Caution
11.7
Glossary
12
Mechanical, Packaging, and Orderable Information
Package Options
Mechanical Data (Package|Pins)
PWP|14
MPDS370A
Thermal pad, mechanical data (Package|Pins)
PWP|14
PPTD287A
Orderable Information
snvsaf9a_oa
snvsaf9a_pm