SLVSIO8
September 2026
TPS638221
PRODMIX
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
Typical Characteristics
7
Detailed Description
7.1
Overview
7.2
Functional Block Diagram
7.3
Feature Description
7.3.1
Control Scheme
7.3.1.1
Buck Operation
7.3.1.2
Boost Operation
7.3.1.3
Buck-Boost Operation
7.3.2
Operation Mode
7.3.2.1
PFM Operation
7.3.2.2
Forced-PWM Operation (FPWM)
7.3.2.3
Ultra-sonic Mode Operation
7.3.3
Undervoltage Lockout (UVLO)
7.3.4
Enable and Soft Start
7.3.5
Protection Functions
7.3.5.1
Input Voltage Protection (IVP)
7.3.5.2
Output Voltage Protection (OVP)
7.3.5.3
Current Limit Mode and Overcurrent Protection
7.3.5.4
Output Short Circuit Protection (Hiccup)
7.3.5.5
Thermal Shutdown
7.3.6
Power Good
7.3.7
Load Disconnect
7.3.8
Output Discharge
7.4
Device Functional Modes
8
Application and Implementation
8.1
Application Information
8.2
Typical Applications
8.2.1
3.3V Output Power Supply
8.2.1.1
Design Requirements
8.2.1.2
Detailed Design Procedure
8.2.1.2.1
Inductor Selection
8.2.1.2.2
Output Capacitor Selection
8.2.1.2.3
Input Capacitor Selection
8.2.1.2.4
Setting the Output Voltage
8.2.1.3
Application Curves
8.3
Power Supply Recommendations
8.4
Layout
8.4.1
Layout Guidelines
8.4.2
Layout Example
9
Device and Documentation Support
9.1
Device Support
9.1.1
Third-Party Products Disclaimer
9.1.2
Third-Party Products Disclaimer
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
Export Control Notice
9.8
Glossary
10
Revision History
11
Mechanical, Packaging, and Orderable Information
67
2
Applications
System pre-regulator
Point-of-load regulation
Optical modules
Broadband network radio or SoC supply