SLVSHP9 July 2026 TPS544A28
PRODUCTION DATA
The device has a power-good (PG or PGOOD) output that goes high to indicate when the converter output is in regulation. The power-good output is an open-drain output and must be pulled up to the VCC pin or an external voltage source (< 5.5V) through a pullup resistor (typically 30.1kΩ) to go high. The recommended power-good pullup resistor value is 1kΩ to 100kΩ.
After the soft-start ramp finishes, the power-good signal becomes high after a internal delay tPG_DLY. An internal soft-start done signal goes high when the SS voltage reachesVSS(DONE) to indicate the soft-start ramp has finished. If the FB voltage drops to 85% of the VREF voltage or exceeds 110% of the VREF voltage, the power-good signal latches low after a 4µs internal delay. The power-good signal can only be pulled high again after re-toggling EN or a reset of VIN.
If an OV event causes the FB voltage to exceed the OV threshold during soft start, but the FB voltage drops below the OV threshold before soft-start is completed, the power-good signal does not latch low until FB exceeds the OV threshold or drops below UV threshold. The OV or UV event must occur after the soft-start ramp finishes for the power-good signal to latch low. FB exceeding the OV threshold during soft start does, however, trigger the OV fault, and the devices response to OV (described in Overvoltage and Undervoltage Protection) typically pulls the output voltage below the UV threshold.
If the input supply fails to power up the device (for example, VIN and VCC both stay at zero volts) and this pin is pulled up through an external resistor, the power-good pin clamps low to the low-level specified in the POWER GOOD section in the Electrical Characteristics