The TPSM5601R5 provides a PGOOD signal to indicate when the output voltage is within regulation. Use the PGOOD signal for output monitoring, fault protection, or start-up sequencing of downstream converters. PGOOD is an open-drain output that requires a pullup resistor to a DC supply not greater than 18 V. V5V or VOUT can be used as the pullup voltage source. Typical range of pullup resistance is 10 kΩ to 100 kΩ. If necessary, use a resistor divider to decrease the voltage from a higher voltage pullup rail. If this function is not needed, the PGOOD pin must be grounded.

When the output voltage exceeds 95% (rising) or decreases below 105% (falling) of the setpoint, the internal PGOOD switch turns off and PGOOD can be pulled high by the external pullup. If the FB voltage falls below 93% or rises above 107% of the setpoint, the internal PGOOD switch turns on, and PGOOD is pulled low to indicate that the output voltage is out of regulation.

Note that during initial power up, a delay of about 4 ms (typical) is inserted from the time that EN is asserted to the time that the power-good flag goes high. This delay only occurs during start-up and is not encountered during normal operation of the power-good function.