TPS25984x needs the SWEN pin to be pulled up to a supply rail which is powered up before the device is enabled. Failing this, the device is not able to turn on the output. The SWEN pullup supply must not be derived from the output of the eFuse. Use one of the following options to derive the pullup supply rail for SWEN.
- Use an existing standby rail in the system, which is derived from the main power input and comes up before the eFuse is turned on.
- Use an LDO (3.3 V or 5 V) powered from the main power input.
- Use a Zener regular powered from the main power input.
- Use the ITIMER pin of the primary eFuse. Ensure the ITIMER pin does not have excess loading which can interfere with the normal overcurrent blanking timer functionality.
The PG is an open-drain pin and must be pulled up to an external supply. Do not leave the PG pin floating or force the pin low externally during steady-state as it can interfere with the device operation.