nRF5340-DK operating voltage at 1.8V?

RE: nRF5340-DK operating voltage at 1.8V?

Jared — Tue, 17 Jan 2023 11:15:27 GMT

Hi,

Alright Steve,

I'll do that,

regards

Jared

RE: nRF5340-DK operating voltage at 1.8V?

SteveG128 — Mon, 16 Jan 2023 22:24:08 GMT

Jared,

You can close this, my hardware works fine @ 1.8V. The DK does not so it's gone to the recycle bin.

Thanks

Steve

RE: nRF5340-DK operating voltage at 1.8V?

Jared — Thu, 24 Nov 2022 08:28:51 GMT

Hi.

alright, keep me updated.

regards

Jared

RE: nRF5340-DK operating voltage at 1.8V?

SteveG128 — Wed, 23 Nov 2022 18:50:38 GMT

Jared,

The lowest voltage my DK will activate the I2C bus at is 2.45 volts. The DK runs code at 1.8V, no resets are occurring but the GPIOs are non-functional. I going to assume that my DK is bad, but I'm not going to buy another on the hope that it would work.

My hardware's arrival is imminent so I'll wait for that rather than wasting any more time with the DK. I will update this conversation when and if my HW is working. Most likely next week.

Steve

RE: nRF5340-DK operating voltage at 1.8V?

Jared — Wed, 23 Nov 2022 11:19:10 GMT

Steve,

I tried to reproduce this with the i2c_fujitsu_fram sample but wasn't able to. I connected a power supply to the P21 external supply connector and saw that there indeed was activity on both SCL and SDA when I lowered the voltage. At 1V8 I would see several resets which I think is brown-out resets but it became stable when I increased it to about 1V9. I did not use external pull ups, instead I modified the dts to activate the internal pullups with pin ctrl like this:

RE: nRF5340-DK operating voltage at 1.8V?

SteveG128 — Tue, 22 Nov 2022 22:16:44 GMT

Hi Jared,

I'm using Version 2.1.0.

I can duplicate the issue using the sample ncs\v2.1.0\zephyr\samples\drivers\i2c_fujitsu_fram

It doesn't matter if there is a I2C device, just the pull-ups on SCL and SDA are required.

Steve

RE: nRF5340-DK operating voltage at 1.8V?

Jared — Mon, 21 Nov 2022 14:02:18 GMT

Hi Steve,

Which version of NCS are you using?

[quote user="SteveG128"]More importantly, if I remove the MAX86171 and simply watch SCL and SDA with the scope, there is no activity on the signals until I supply 3V (it may be a lower voltage, I just tested 1.8V and 3V)[/quote]

Could you share a minimal sample that would reproduce this, so I could recreate this on my DK?

regards
Jared

RE: nRF5340-DK operating voltage at 1.8V?

SteveG128 — Fri, 18 Nov 2022 15:32:45 GMT

Jared,

I'm using a bench supply and the current limit is well above any expected current requirements of the DK.

I'm using connector P1 pin 1 of the DK for the MAX86171 1.8V

More importantly, if I remove the MAX86171 and simply watch SCL and SDA with the scope, there is no activity on the signals until I supply 3V (it may be a lower voltage, I just tested 1.8V and 3V). My shield board pulls up both signals with 4K7 resistors to the DK's Vdd.

Steve

RE: nRF5340-DK operating voltage at 1.8V?

Jared — Fri, 18 Nov 2022 09:59:13 GMT

Hi,

Yes, you should expect both the nRF5340 and a module based on it to be fully functional at 1V8. What power supply source are you using and have you set a current limit on it?

Is MAX86171 supplied directly from your external supply?

regards

Jared