ZHCSHI5D March 2001 – February 2018 TPS791
The TPS791 PMOS-pass transistor has a built-in back diode that conducts reverse current when the input voltage drops below the output voltage (for example, during power-down). Current is conducted from the output to the input and is not internally limited. If extended reverse voltage operation is anticipated, external limiting may be appropriate.
The TPS791 features internal current limiting and thermal protection. During normal operation, the TPS791 limits output current to approximately 400 mA. When current limiting engages, the output voltage scales back linearly until the overcurrent condition ends. Although current limiting is designed to prevent gross device failure, care must be taken not to exceed the power dissipation ratings of the package or the absolute maximum voltage ratings of the device. If the temperature of the device exceeds approximately 165°C, thermal-protection circuitry shuts the device down. When the device cools down to below approximately 140°C, regulator operation resumes.