Datasheet

  
   
SLVS167C − SEPTEMBER 1998 − REVISED − MAY 1999
26
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
APPLICATION INFORMATION
regulator protection
The TPS73HD3xx PMOS-pass transistors have built-in back diodes that safely conduct reverse currents when
the input voltage drops below the output voltage (e.g., during power down). Current is conducted from the output
to the input and is not internally limited. If extended reverse voltage is anticipated, external limiting might be
appropriate.
The TPS73HD3xx also features internal current limiting and thermal protection. During normal operation, the
TPS73HD3xx limits output current to approximately 1 A. When current limiting engages, the output voltage
scales back linearly until the overcurrent condition ends. While current limiting is designed to prevent gross
device failure, care should be taken not to exceed the power dissipation ratings of the package. If the
temperature of the device exceeds 165°C, thermal-protection circuitry shuts it down. Once the device has
cooled, regulator operation resumes.