ZHCSPP3 July 2022 TPS563300
PRODUCTION DATA
- 1 特性
- 2 应用
- 3 说明
- 4 Revision History
- 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 Fixed Frequency Peak Current Mode
- 7.3.2 Pulse Frequency Modulation
- 7.3.3 Voltage Reference
- 7.3.4 Output Voltage Setting
- 7.3.5 Enable and Adjusting Undervoltage Lockout
- 7.3.6 Minimum On Time, Minimum Off Time, and Frequency Foldback
- 7.3.7 Frequency Spread Spectrum
- 7.3.8 Overvoltage Protection
- 7.3.9 Overcurrent and Undervoltage Protection
- 7.3.10 Thermal Shutdown
- 7.4 Device Functional Modes
-
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 Output Voltage Resistors Selection
- 8.2.2.3 Bootstrap Capacitor Selection
- 8.2.2.4 Undervoltage Lockout Set Point
- 8.2.2.5 Output Inductor Selection
- 8.2.2.6 Output Capacitor Selection
- 8.2.2.7 Input Capacitor Selection
- 8.2.2.8 Feedforward Capacitor CFF Selection
- 8.2.2.9 Maximum Ambient Temperature
- 8.2.3 Application Curves
- 8.3 Best Design Practices
- 8.4 Power Supply Recommendations
- 8.5 Layout
- 9 Device and Documentation Support
- 10Mechanical, Packaging, and Orderable Information
8.2.2.2 Output Voltage Resistors Selection
The output voltage is set with a resistor divider from the output node to the FB pin. TI recommends using 1% tolerance or better divider resistors. Referring to the application schematic of Figure 8-1, start with 10.2 kΩ for R7 and use Equation 12 to calculate R6 = 53.6 kΩ. To improve efficiency at light loads, consider using larger value resistors. If the values are too high, the converter is more susceptible to noise and voltage errors from the FB input leakage current are noticeable.
Equation 12. 
Table 8-2 shows the recommended components value for common output voltages.