JAJSG59B september 2018 – december 2020 TPS7A11
PRODUCTION DATA
The active discharge option has an internal pulldown MOSFET that connects a 120-Ω resistor to ground when the device is disabled in order to actively discharge the output voltage. The active discharge circuit is activated by driving the enable pin to logic low to disable the device, or when the device is in thermal shutdown.
The discharge time after disabling the device depends on the output capacitance (COUT) and the load resistance (RL ) in parallel with the 120-Ω pulldown resistor. Equation 1 calculates this time:
Do not rely on the active discharge circuit for discharging a large amount of output capacitance after the input supply has collapsed because reverse current can flow from the output to the input. This reverse current flow can cause damage to the device. Limit reverse current to no more than 5% of the device-rated current.