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
8.2.2.11 Short Circuit Protection (R9)
The devices use the negative drop across the low-side MOSFET during the OFF time to measure the inductor current. Equation 25 approximates the voltage drop across the low-side MOSFET.
Equation 25. 
The internal temperature coefficient of the TPS40192 device helps compensate for the MOSFET on-resistance (RDS(on) ) temperature coefficient. For this design select the short circuit protection voltage threshold of 110 mV by selecting R9 = 3.9 kΩ.