Estimating current consumption of NRF54L15

[Ashokrajpilli]

I would like to estimate the current consumption when the controller is advertising at 2.3Seconds, using external crystal, Tx power of 8dBm, Tx payload of 31 bytes. When I have used nordic power profile it is showing an average current of 9uA. my doubt is how is it estimating? usually it depends on clock frequency of processor but no where i have an access to it. I would like to know the formula to estimate current consumption what all parameters to consider ? 

[Vidar Berg]

Hello,

Please have a look at our online power profiler here: https://devzone.nordicsemi.com/power/w/opp/2/online-power-profiler-for-bluetooth-le. It allows you to estimate the expected current consumption for various configuration parameters such as TX power and advertisement payload.

Best regards,

Vidar

[Ashokrajpilli]

Hi Vidar, 

               There is typo in my sentence above i.e., instead of nordic power profile i have kept nordic powerful. I am aware of profiler but my question is not related to TX power/advertisement payload, how did the tool estimates the current consumption without considering the clock frequency? Need indetail information. 

[Vidar Berg]

Hi,

The CPU can technically be configured to run at 64 MHz, but bluetooth is only tested and qualified at the default 128 MHz frequency. In other words, 64 MHz is not supported.

[Ashokrajpilli]

At what  frequency nordic power profiler is considering? for bluetooth and processor ? 

[Vidar Berg]

It is using 128 MHz and this is the only supported frequency.

[Ashokrajpilli]

I need a formula vidar because i need to calculate for 64 MHz, 16 MHz and decide what is the preferred frequency for my application as it impact current consumption. 

[Vidar Berg]

As mentioned earlier, those frequencies are not supported. That is also why no measurements are provided. 

[Ashokrajpilli]

Thanks Vidar, Now I understand you are referring to only 128 MHz that is run for bluetooth/radio. Apologies for the confusion created. I had a trouble understanding the clock tree how the processor clock, bluetooth clock is related,
I am with an understanding that processor clock is different, bluetooth/RF clock is different. 

1. can Processor clock run at different frequency other than bluetooth clock? 
2. if yes, can you point out in the datasheet/any nordic hyper link  so that i can get high level understanding. 

[Vidar Berg]

Hi, it is the Bluetooth SW stack requires that the CPU to run at 128 MHz:

Vidar Berg said:

The CPU can technically be configured to run at 64 MHz, but bluetooth is only tested and qualified at the default 128 MHz frequency. In other words, 64 MHz is not supported.

There is no relation between the CPU frequency and the radio frequency. How the 2.4 GHz signal is generated from the crystal oscillator is also not included in the documentation.