nRF54L15 power domains effect on current consumption

RE: nRF54L15 power domains effect on current consumption

Edvin — Mon, 02 Jun 2025 12:42:06 GMT

Hello,

It is correct that it used to say, in a previous version of the datasheet, that you could use dedicated pins on P2 for TWIM20-22, but that was a documentation bug. In addition, it never said what these dedicated pins were, like it does for the other peripherals working on dedicated pins on P2, such as SPIM00:

(source: https://docs.nordicsemi.com/bundle/ps_nrf54L15/page/chapters/pin.html#ariaid-title4)

[quote user="WoutWG"]The weird thing is that if I test my custom PCB, I actually do get data from the sensor, but it seems to only happen when I connect my JLINK for logging over RTT[/quote]

It may be, if your PCB has an older revision of the nRF54l15, that the behavior was a bit different. Enabling the RTT viewer will actually put the chip in debug mode, so it will change the clock behavior on the chip. However, officially, TWI is not supported on P2, so even if it works under some conditions on some revisions of the chip (in this case, debug mode), you should not use the for production.

Best regards,

Edvin

RE: nRF54L15 power domains effect on current consumption

WoutWG — Mon, 02 Jun 2025 10:09:51 GMT

Hi Edvin,

I finally got to doing some more tests on this, and I couldn't get things to work on the nRF54L15 DK. Upon reviewing the datasheet I noticed that the TWI/I2C doesn't seem to be available on P2, and unfortunately, that's where I have my pins routed. On the nRF54L15 DK (v0.9.1) there is no I2C traffic at all on the same P2 pins that I have on the PCB. The weird thing is that if I test my custom PCB, I actually do get data from the sensor, but it seems to only happen when I connect my JLINK for logging over RTT. Very strange, but I'll need to reconfirm if this is actually happening.

RE: nRF54L15 power domains effect on current consumption

WoutWG — Thu, 17 Apr 2025 10:12:56 GMT

Thanks Edvin, I was indeed already thinking to try and replicate the behavior on an nRF54L15 DK. I'll keep you posted.

RE: nRF54L15 power domains effect on current consumption

Edvin — Wed, 16 Apr 2025 20:11:19 GMT

Hello,

Indeed, your second PPK screenshot looks a bit unexpected. I can't tell, only by looking at this, what's going on. But for one, you have a base-current of approximately 200µA, which seems a bit high.

Is it possible to zip and send the application that you are currently testing? And feel free to specify where the change you did is located, so that I can easily switch between the two.

I don't suppose you are able to reproduce these graphs on an nRF54L15 DK without the actual sensor attached?

Please note that we have a public holiday here in Norway, so please expect some delay in our replies. We will be back with normal staffing on Tuesday next week.

Best regards,

Edvin