ZHCSI13J October 2004 – November 2018 TPS75003
PRODUCTION DATA.
- 1 特性
- 2 应用
- 3 说明
- 4 修订历史记录
- 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 Operation (Buck Controllers)
- 7.3.2 Enable (Buck Controllers)
- 7.3.3 UVLO (Buck Controllers)
- 7.3.4 Current Limit (Buck Controllers)
- 7.3.5 Short-Circuit Protection (Buck Controllers)
- 7.3.6 Soft-Start (Buck Controllers)
- 7.3.7 LDO Operation
- 7.3.8 Internal Current Limit (LDO)
- 7.3.9 Enable Pin (LDO)
- 7.3.10 Dropout Voltage (LDO)
- 7.3.11 Transient Response (LDO)
- 7.3.12 Thermal Protection (LDO)
- 7.3.13 Power Dissipation (LDO)
-
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 Input Capacitor CIN1, CIN2 Selection (Buck Controllers)
- 8.2.2.2 Inductor Value Selection (Buck Controllers)
- 8.2.2.3 External PMOS Transistor Selection (Buck Controllers)
- 8.2.2.4 Diode Selection (Buck Controllers)
- 8.2.2.5 Output Capacitor Selection (Buck Controllers)
- 8.2.2.6 Output Voltage Ripple Effect on VOUT (Buck Controllers)
- 8.2.2.7 Soft-Start Capacitor Selection (Buck Controllers)
- 8.2.2.8 Output Voltage Setting Selection (Buck Controllers)
- 8.2.2.9 Input Capacitor Selection (LDO)
- 8.2.2.10 Output Capacitor Selection (LDO)
- 8.2.2.11 Soft-Start Capacitor Selection (LDO)
- 8.2.2.12 Setting Output Voltage (LDO)
- 8.2.3 Application Curves
- 9 Power Supply Recommendations
- 10Layout
- 11器件和文档支持
- 12机械、封装和可订购信息
8.2.2.5 Output Capacitor Selection (Buck Controllers)
The output capacitor is selected based on output voltage ripple and transient response requirements. As a result of the nature of the hysteretic control loop, a minimum ESR of a few tens of mΩ should be maintained for good operation unless a feed-forward resistor is used. Low ESR bulk tantalum or PosCap capacitors work best in most applications. A 1.0μF ceramic capacitor can be used in parallel with this capacitor to filter higher frequency spikes. The output voltage ripple can be estimated by Equation 12:
To calculate the capacitance needed to achieve a given voltage ripple as a result of a load transient from zero output to full current, use Equation 13:
If only ceramic or other very low ESR output capacitor configurations are desired, additional voltage ripple must be passed to the feedback pin. For detailed application information, refer to the Using Ceramic Output Capacitors with the TPS6420x and TPS75003 Buck Controllers application report.