NRF52833 VDD External Power

[chethans]

Hi,

Is it possible to power external devices through VDD ports of NRF52833 provided we follow the VDDH supply configuration?

We are looking to power sensors from the controller. The total current will be less than 10mA.

Thank you,

Chethan  

[chethans]

Thanks ketiljo.

Can we get the different modes and currents for it?

We are designing a low power product and every uA is crucial.

With the ldo turned on, does it burn complete power across vddh - regout0? Or is there some smart mechanism which avoids this?

[ketiljo]

You will be better off using the nRF52840 as this have a DCDC mode for REG0 (VDDH). This is a lot better for low current applications. The nRF52833 doesn't have DCDC mode at REG0 so this will just burn off the current as any other LDO.

The nRF52840 can power external circuitry as well.  

[chethans]

Only if 52840 could support 105 deg

[ketiljo]

Ok. The best will be to use an external DCDC converter to take the battery voltage down to 3 V or so as this will be much more efficient than the LDO in the nRF52833.

I didn't expect hat you needed 105 degrees since you where talking about batteries, that won't work too unless the battery is somewhere else?

[chethans]

We are using a variant of lithium thionyl chloride batteries which can support up to 125 deg. Its an industrial iot application with very stringent requirements