ZHCSL91B October 2020 – March 2022 TPS25947
PRODUCTION DATA
- 1 特性
- 2 應用
- 3 說明
- 4 Revision History
- 5 Device Comparison Table
- 6 Pin Configuration and Functions
- 7 Specifications
-
8 Detailed Description
- 8.1 Overview
- 8.2 Functional Block Diagram
- 8.3
Feature Description
- 8.3.1 Input Reverse Polarity Protection
- 8.3.2 Undervoltage Lockout (UVLO and UVP)
- 8.3.3 Overvoltage Lockout (OVLO)
- 8.3.4 Overvoltage Clamp (OVC)
- 8.3.5 Inrush Current, Overcurrent, and Short Circuit Protection
- 8.3.6 Analog Load Current Monitor
- 8.3.7 Reverse Current Protection
- 8.3.8 Overtemperature Protection (OTP)
- 8.3.9 Fault Response and Indication (FLT)
- 8.3.10 Auxiliary Channel Control (AUXOFF)
- 8.3.11 Power Good Indication (PG)
- 8.4 Device Functional Modes
- 9 Application and Implementation
- 10Power Supply Recommendations
- 11Layout
- 12Device and Documentation Support
- 13Mechanical, Packaging, and Orderable Information
8.3.4 Overvoltage Clamp (OVC)
The TPS259472x variants implement a voltage clamp on the output to protect the system in the event of input overvoltage. When the device detects the input has exceeded the Overvoltage Clamp Threshold (VOVC), it quickly responds within tOVC and stops the output from rising further and then regulates the HFET linearly to clamp the output voltage below VCLAMP as long as an overvoltage condition is present on the input.
If the part stays in clamping state for an extended period of time, there is a higher power dissipation inside the part which can eventually lead to thermal shut-down (TSD). After the part shuts down due to TSD fault, it can either stay latched off (TPS259472L variant) or restart automatically after a fixed delay (TPS259472A variant). See Overtemperature Protection (OTP) for more details on device response to overtemperature.
Figure 8-8 TPS259472x Overvoltage Response
(Auto-Retry)There are 3 available overvoltage clamp threshold options which can be configured using the OVCSEL pin.
| OVCSEL Pin Connection | Overvoltage Clamp Threshold |
|---|---|
| Shorted to GND | 3.8 V |
| Open | 5.7 V |
| Connected to GND through a 390-kΩ resistor | 13.8 V |