SNVSCH2
September 2024
LM65645-Q1
ADVANCE INFORMATION
1
1
Features
2
Applications
3
Description
4
Device Comparison Table
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
System Characteristics
7
Detailed Description
7.1
Overview
7.2
Functional Block Diagram
7.3
Feature Descriptions
7.3.1
Output Voltage Selection
7.3.2
EN Pin and Use as VIN UVLO
7.3.3
Mode Selection
7.3.3.1
MODE/SYNC Pin Uses for Synchronization
7.3.3.2
Clock Locking
7.3.4
Adjustable Switching Frequency
7.3.5
Dual Random Spread Spectrum (DRSS)
7.3.6
Internal LDO, VCC UVLO, and BIAS Input
7.3.7
Bootstrap Voltage (BST Pin)
7.3.8
Soft Start and Recovery From Dropout
7.3.9
Safety Features
7.3.9.1
Power-Good Monitor
7.3.9.2
Overcurrent and Short-Circuit Protection
7.3.9.3
Hiccup
7.3.9.4
Thermal Shutdown
7.4
Device Functional Modes
7.4.1
Shutdown Mode
7.4.2
Active Mode
7.4.2.1
Peak Current Mode Operation
7.4.2.2
Auto Mode Operation
7.4.2.2.1
Diode Emulation
7.4.2.3
FPWM Mode Operation
8
Application and Implementation
8.1
Application Information
8.2
Typical Application
8.2.1
Design Requirements
8.2.2
Detailed Design Procedure
8.2.2.1
Custom Design With WEBENCH® Tools
8.2.2.2
Choosing the Switching Frequency
8.2.2.3
FB for Adjustable or Fixed Output Voltage Mode
8.2.2.4
Inductor Selection
8.2.2.5
Output Capacitor Selection
8.2.2.6
Input Capacitor Selection
8.2.2.7
CBOOT
8.2.2.8
External UVLO
8.2.2.9
Maximum Ambient Temperature
8.3
Best Design Practices
8.4
Power Supply Recommendations
8.5
Layout
8.5.1
Layout Guidelines
8.5.1.1
Ground and Thermal Considerations
8.5.2
Layout Example
9
Device and Documentation Support
9.1
Device Support
9.1.1
Third-Party Products Disclaimer
9.1.2
Development Support
9.1.2.1
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
11.1
Tape and Reel Information
Package Options
Mechanical Data (Package|Pins)
RZT|20
Thermal pad, mechanical data (Package|Pins)
Orderable Information
snvsch2_oa
9.2.1
Related Documentation
For related documentation, see the following:
Texas Instruments,
Thermal Design by Insight not Hindsight
application report
Texas Instruments,
A Guide to Board Layout for Best Thermal Resistance for Exposed Pad Packages
application report
Texas Instruments,
How to Properly Evaluate Junction Temperature with Thermal Metrics
application report
Texas Instruments,
Layout Guidelines for Switching Power Supplies
application report
Texas Instruments,
Simple Switcher PCB Layout Guidelines
application report
Texas Instruments,
Construction Your Power Supply- Layout Considerations
seminar
Texas Instruments,
Low Radiated EMI Layout Made Simple with LM4360x and LM4600x
application report
Texas Instruments,
Semiconductor and IC Package Thermal Metrics
application note