ZHCS979F June 2012 – October 2020 TPS53318 , TPS53319
PRODUCTION DATA
- 1 特性
- 2 应用
- 3 说明
- 4 Revision History
- 5 Device Comparison Table
- 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 5-V LDO and VREG Start-Up
- 8.3.2 Adaptive On-Time D-CAP Control and Frequency Selection
- 8.3.3 Ramp Signal
- 8.3.4 Adaptive Zero Crossing
- 8.3.5 Output Discharge Control
- 8.3.6 Power-Good
- 8.3.7 Current Sense, Overcurrent, and Short Circuit Protection
- 8.3.8 Overvoltage and Undervoltage Protection
- 8.3.9 Redundant Overvoltage Protection (OVP)
- 8.3.10 UVLO Protection
- 8.3.11 Thermal Shutdown
- 8.3.12 Small Signal Model
- 8.3.13 External Component Selection Using All Ceramic Output Capacitors
- 8.4 Device Functional Modes
-
9 Application and Implementation
- 9.1 Application Information
- 9.2
Typical Applications
- 9.2.1
Application Using Bulk Output Capacitors, Redundant Overvoltage Protection Function (OVP) Disabled
- 9.2.1.1 Design Requirements
- 9.2.1.2
Detailed Design Procedure
- 9.2.1.2.1 Step One: Select Operation Mode and Soft-Start Time
- 9.2.1.2.2 Step Two: Select Switching Frequency
- 9.2.1.2.3 Step Three: Choose the Inductor
- 9.2.1.2.4 Step Four: Choose the Output Capacitor or Capacitors
- 9.2.1.2.5 Step Five: Determine the Value of R1 and R2
- 9.2.1.2.6 Step Six: Choose the Overcurrent Setting Resistor
- 9.2.1.3 Application Curves
- 9.2.2 Application Using Ceramic Output Capacitors, Redundant Overvoltage Protection Function (OVP) Enabled
- 9.2.1
Application Using Bulk Output Capacitors, Redundant Overvoltage Protection Function (OVP) Disabled
- 10Power Supply Recommendations
- 11Layout
- 12Device and Documentation Support
- 13Mechanical, Packaging, and Orderable Information
9.2.1.2.5 Step Five: Determine the Value of R1 and R2
The output voltage is programmed by the voltage-divider resistor, R1 and R2 shown in Figure 8-4. R1 is connected between VFB pin and the output, and R2 is connected between the VFB pin and GND. Recommended R2 value is from 10 kΩ to 20 kΩ. Determine R1 using Equation 17.
Equation 17. 