Is it possible to disable external circuitry power in system off mode?

[addast]

I want to use nrf52840 in high voltage mode, with 3.3v ldo voltage output.

I need to be able to disable vcc output during sleep mode. Is it possible?

[ketiljo]

You will need to use a switch or a transistor in that case then. VDD is the power supply to the nRF52840 and if you cut that, the device will power down for good.