SLUSF22 November 2024 TPS54538
PRODUCTION DATA
When the TPS54538 is configured to PG function, the SS/PG pin is used to indicate whether the output voltage has reached the appropriate level or not. The PG signal can be used for start-up sequencing of multiple rails. The PG pin is an open-drain output that requires a pullup resistor to any voltage below 5.5V. TI recommends a pullup resistor of 10kΩ – 100kΩ. The device can sink approximately 4mA of current and maintain the specified logic low level. After the FB pin voltage is between 90% and 107% of the internal reference voltage (VREF) and after a deglitch time of 70μs, the PG turns to high impedance status. The PG pin is pulled low after a deglitch time of 13μs when FB pin voltage is lower than 85% of the internal reference voltage or greater than 115% of the internal reference voltage, or in events of thermal shutdown, EN shutdown, or UVLO conditions. VIN must remain present for the PG pin to stay low.
Device State | PG Logic Status | ||
---|---|---|---|
High Impedance | Low | ||
Enable (EN = High) | VFB does not trigger VPGTH | √ | |
VFB triggers VPGTH | √ | ||
Shutdown (EN = Low) | √ | ||
UVLO | 2.5V < VIN < VUVLO | √ | |
Thermal shutdown | TJ > TSD | √ | |
Power supply removal | VIN < 2.5V | √ |