ZHCSH96H MARCH 2007 – May 2019 TPS40192 , TPS40193
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
-
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 Selecting the Switching Frequency
- 8.2.2.2 Inductor Selection
- 8.2.2.3 Output Capacitor Selection (C8)
- 8.2.2.4 Peak Current Rating of the Inductor
- 8.2.2.5 Input Capacitor Selection (C7)
- 8.2.2.6 MOSFET Switch Selection (Q1, Q2)
- 8.2.2.7 Boot Strap Capacitor
- 8.2.2.8 Input Bypass Capacitor (C6)
- 8.2.2.9 BP5 Bypass Capacitor (C5)
- 8.2.2.10 Input Voltage Filter Resistor (R11)
- 8.2.2.11 Short Circuit Protection (R9)
- 8.2.2.12 Feedback Compensation (Modeling the Power Stage)
- 8.2.2.13 Feedback Divider (R7, R8)
- 8.2.2.14 Error Amplifier Compensation (R6, R10, C1, C2, C3)
- 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
8.2.2.7 Boot Strap Capacitor
To ensure proper charging of the high-side MOSFET gate, limit the ripple voltage on the boost capacitor to less than 50 mV.
Use the next higher standard value of 470 nF for the value of the bootstrap capacitor.
NOTE
It is recommended to add a high-resistance resistor in parallel with the bootstrap capacitor. Adding a small amount of load to the bootstrap capacitor (100 kΩ for a 100-nF typical capacitor) creates a discharge time constant for the bootstrap voltage following a shutdown event. This prevents the possibility of an inadvertent turn-on of the high-side MOSFET following shutdown via the ENABLE pin, due to leakage paths within the driver stage which can slowly transfer the bootstrap voltage to the HDRV pin following the shutdown. (See Figure 15)