Section 7.3.3 of the TPS780.pdf data sheet indicates that the TPS780 series includes an active pulldown to discharge Vout when the device is off. There is very little detail about the functionality of this feature. In the block diagram figure in section 7.2 it shows the pulldown is 10K ohms.
In section 7.1 Overview it is stated "The absence of pulldown circuitry at the output of the LDO provides the flexibility to use the regulator output capacitor as a temporary backup power supply for a short period of time (for example, during battery replacement)."
When I run a simple simulation with the PSICE model for the TPS78001 with Vin = 5V for all time and the EN pin being pulsed from 0 to 3.3V for about 100mS and the output set to 2.8V with a 4.7uF capacitor on the output and no other load I see the output takes about 1 minute to discharge. If there were an active pulldown of 10Kohms it should take less than a second.
Can you provide some clarification regarding this Active Pulldown circuit and if it is there or not and if it is in the encrypted PSPICE model if so?
