ZHCSKX0 February 2020 TPS59632-Q1
PRODUCTION DATA.
PGOOD is an open-drain output pin that is designed to be pulled-up with an external resistor to a voltage 3.6 V or less. Normal PGOOD operation (exclusive of activation of any faults) is shown in Figure 16. On initial power-up PGOOD happens within 6 µs of the DAC reaching its target value. When EN is brought low, PGOOD is also brought low for 250 µs, then is allowed to float. The TPS59632-Q1 device pulls down the PGOOD signal when the EN signal subsequently goes high and returns high again within 6 µs of the end of the DAC ramp. The delay period between EN going high and PGOOD going low in this case is less than 1 µs. Figure 16 shows the power good operation at initial start-up and with falling and rising EN.
For applications where it is undesirable to have PGOOD high when EN is low, an alternate method of pulling up the open-drain PGOOD signal is possible. In this method, the PGOOD is pulled up to EN logic signal. This ensures that the PGOOD is low when EN goes low.
Figure 16. Power Good Operation