The purpose of the output discharge function is to ensure a defined down-ramp of the output voltage when the device is disabled and to keep the output voltage close to 0 V. The output discharge feature is only active once the device has been enabled at least once since the supply voltage was applied. The output discharge function is not active if the device is disabled and the supply voltage is applied the first time.
The internal discharge resistor is connected to the VOS pin. The discharge function is enabled as soon as the device is disabled. The minimum supply voltage required to keep the discharge function active is VIN > VTH_UVLO-.