GPIO open-drain configuration

[Luke_123]

Hi Team,

I am using nRF52810 gpio to power gate (gpio connected to VIN) ADXL362 . But the ADXL362 recommends a switch(SHUTDOWN) as shown below to discharge the capacitors on the VDD line before powering on. 

But we missed adding the mosfet and have been thinking if there is any other way to discharge the capacitors on the VDD line using GPIO. Is there an option to configure the GPIO as open-drain to discharge the capacitors ? What would you suggest ?

[hmolesworth]

Don't need a MOSFET or R1, the nRF52 already has one. Just make the GPIO pin providing VIN configured (CNF) as a high-drive H0H1 (not open-drain) and the pin will discharge the capacitor when it is set low. There will be a finite time while the capacitor charges (turning VIN on) and later discharges (turning VIN off) so a small delay will be needed to ensure the VIN pin is fully charged or discharged, maybe few hundred uSecs depending on C5 and C10. Internal MOFET R equivalent is (say) 100 Ohm.