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  

[ketiljo]

External power from the VDD pin is not supported on the nRF52833.

[chethans]

Hi,

Needed one more clarification for the power supply.

Does NRF52833 operate at 3.7V connected to VDD?

We have 3.6V batteries and initially their voltage will be a little high. Can NRF still operate with this slight extra voltage?

[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

[ketiljo]

The advice will be to use an external DCDC converter with the nRF52833 then. Or maybe the nRF52820 can fit the bill: https://www.nordicsemi.com/News/2020/03/Nordic-nRF52820-SoC-the-sixth-addition-to-the-nRF52-Series?utm_campaign=SoMe%20promotion&utm_source=facebook&utm_medium=social&utm_content=News%20release:%20nRF52820

[chethans]

We ended up using an external DCDC. Thanks for your help though. Appreciate it. nRF52820 looks interesting but we need a large RAM size as well

Is there any plan of supporting 105 deg with 256kb RAM in the future?

[ketiljo]

The new nRF53 series possibly, here's the first device:  https://infocenter.nordicsemi.com/topic/ps_nrf5340/keyfeatures_html5.html

[chethans]

Hi ketiljo,

Had one more query on the hardware design.

In infocentre, the following is mentioned:

Note: If SPIM0, SPIM1, or SPIM2 is used with 8 Mbps data rate, the recommended GPIOs for the clock signal (SCK) are P0.27, P1.08, P0.04, and P1.09.

Any reason for using this particular lines?

We have been using SPI at 8MHz with P0.17 and seems to be working fine. So wondering why the special note above?

Thank you,

Chethan

[ketiljo]

It works with other pins as well. These pins where probably looked as the best suited when it comes to not disturbing the radio. As long as you don't use any of the pins that are recommended for low frequency use only, you're fine.