ZHCSHF3C january 2018 – may 2023 TPS65268-Q1
PRODUCTION DATA
- 1
- 1 特性
- 2 应用
- 3 描述
- 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 Adjusting the Output Voltage
- 7.3.2 Enable and Adjusting UVLO
- 7.3.3 Soft-Start Time
- 7.3.4 Power-Up Sequencing
- 7.3.5 V7V Low-Dropout Regulator and Bootstrap
- 7.3.6 Out-of-Phase Operation
- 7.3.7 Output Overvoltage Protection (OVP)
- 7.3.8 Slope Compensation
- 7.3.9 Overcurrent Protection
- 7.3.10 Power Good
- 7.3.11 Thermal Shutdown
- 7.4 Device Functional Modes
- 8 Application and Implementation
- 9 Device and Documentation Support
- 10Mechanical, Packaging, and Orderable Information
8.2.2.3 Input Capacitor Selection
The TPS65268-Q1 device requires a high-quality ceramic, type X5R or X7R, input decoupling capacitor with at least 10 µF of effective capacitance on the PVIN input voltage pins. In some applications, additional bulk capacitance can also be required for the PVIN input. The effective capacitance includes any DC bias effects. The voltage rating of the input capacitor must be greater than the maximum input voltage. The capacitor must also have a ripple current rating greater than the maximum input current ripple of the TPS65268-Q1. Use Equation 14 to calculate the input ripple current (IINrms ).
The value of a ceramic capacitor varies significantly over temperature and the amount of DC bias applied to the capacitor. The capacitance variations because of temperature can be minimized by selecting a dielectric material that is stable over temperature. Ceramic dielectric capacitors with type X5R and X7R are usually selected for power regulator capacitors because they have a high capacitance-to-volume ratio and are fairly stable over temperature. The DC bias must also be considered when selecting an output capacitor. The capacitance value of a capacitor decreases as the DC bias across a capacitor increases. The input capacitance value determines the input ripple voltage of the regulator. Use Equation 15 to calculate the input voltage ripple (ΔVIN).
