Our nRF52832 application PCB's battery level is dropped every 1024 secs

[Daewoong Kim]

Hi,

I've developed nRF52832 chip for our company's application,

and I found some weird phenomenon

we using nRF52832 chip with Nordic softdeivce and SDK v12,

BLE chip operates with DCDC converter (internally),

The power is supplied by 3V coin cell.

The above figure shows VDD voltage of BLE chip. Those values measured by SA-ADC module in BLE chip

every 1 second, and our custom hardware keep stored in refrigeration room (about -20 C).

As you could see, the VDD value have dropped every certain period. The period is about 1024 secs.

Anyone knows that? why this phenomenon is being observed..?

Thank you for your helps

- Daewoong Kim

[haakonsh]

In addition to the previous answers, I'd like to add that your data has a bad case of aliasing, your sampling period is far too low. 
Also, due to the voltage drops previously explained, what you're really measuring is the power consumption of the device, but with a source that is unable to deliver the required load. I suggest you make a proper analysis of your power consumption by measuring the current consumption at a constant voltage and with a high sample rate. 

See Measuring current for more details.