NRF52840 logic level (3.3V) Available

RE: NRF52840 logic level (3.3V) Available

Vijil Jose — Wed, 22 Feb 2023 12:21:24 GMT

Ok. you can close the ticket

RE: NRF52840 logic level (3.3V) Available

Jared — Wed, 22 Feb 2023 11:50:49 GMT

Then it's probably better to use 1V8.

RE: NRF52840 logic level (3.3V) Available

Vijil Jose — Wed, 22 Feb 2023 11:23:45 GMT

Thanks for your response. My Peripherals are QSPI flash and IMU sensor, both will work on 1.8V as well

RE: NRF52840 logic level (3.3V) Available

Jared — Wed, 22 Feb 2023 10:05:56 GMT

Hi,

If you're using High voltage mode( HV mode) and supplying the nRF52840 with 3V3 from a battery then the efficiency whether the output from the REG0 regulator is 1V8 or 3V3 is not much in difference if you're using DC/DC for both REG0 and REG1.1V8 will be a tiny more efficient if you're only using DC/DC for one of the stages. But in the end, the digital voltage VDD should be chosen based on the VDD of external components.

regards

Jared

RE: NRF52840 logic level (3.3V) Available

Vijil Jose — Tue, 21 Feb 2023 18:09:38 GMT

Thanks for the info. So is there any efficiency advantage, if we keep the VDD same as 1.8V

RE: NRF52840 logic level (3.3V) Available

Jared — Tue, 21 Feb 2023 09:04:52 GMT

[quote user="Vijil Jose"]can you give an example code for the same.[/quote]

See this guide.

[quote user="Vijil Jose"]also, all the SPI, UART voltage level also get changed by this correct?[/quote]

Yes, all GPIOs will run at VDD,

[quote user="Vijil Jose"]Is there any advantage of running CPU in 1.8V compare to 3.3V?[/quote]

The CPU will not run on 3V3, only VDD, VDD will always be regulated down to 1V3 which is the system voltage:

regards

Jared

RE: NRF52840 logic level (3.3V) Available

Vijil Jose — Mon, 20 Feb 2023 16:00:10 GMT

can you give an example code for the same. also, all the SPI, UART voltage level also get changed by this correct?
Is there any advantage of running CPU in 1.8V compare to 3.3V?

RE: NRF52840 logic level (3.3V) Available

Jared — Mon, 20 Feb 2023 08:25:27 GMT

Hi,

When using VDDH as input(High Voltage mode), VDD pin will be output, and the default voltage of VDD is 1V8. All GPIOs will always run at VDD voltage. You can change VDD output voltage by writing to the REGOUT0 register.

regards
Jared