Standby current for nRF52832.

[W.F.K]

Hello,

Our team is new on development nRF52832 firmware.

Now we have an issue on standby current for nRF52832.

We have a 5 second timer for a PWM output.

Sleep (System on, 32768Hz crystal) for 4 seconds -> wake up & battery level ADC + PWM output 1 second -> sleep again and loop

Here is the schematic:

Now, we get 0.5mA current while in the 4 second sleep time.

Is it totally not reasonable? it won't be such high, right?

Any idea or hint to me? 

And is it possible to provide me any sample code / hex file (system on sleep mode) to me, so that i can download to my PCB to measure standby current for verification?

Thank you very much & Sorry for newbie here.

[Otso Jousimaa]

It sounds like your HFCLK remains on to me, do you uninitialize the PWM driver when going to sleep?

The Nordic SDK has examples/peripheral/pwr_mgmt which should be a good FW for checking the sleep modes. 

[W.F.K]

Thanks, after check, the HFCLK remain on and PWM driver is already uninitialized.

I will check again after HFCLK is set to off.

But it seems still high in current for 0.7mA, should be another reasons for such high current.

I will look into again by checking the SDK examples. 

[W.F.K]

We have turned off the HFCLK and confirmed all driver & GPIOs are released.

However, we still get 0.5mA current for just a timer of 5 seconds.

We are still looking into the codes and see if any comments or recommandation can be provided.

Thank you very much.

[Otso Jousimaa]

0.5 mA sounds just way too high. Have you tested your code and Nordic example on Nordic devkit? That should let you narrow down if the source of current drain is in HW or SW

[W.F.K]

We have tested the sample codes, for example, ble_app_hrs_rscs_relay. We have tested this code and it is 0.7mA~6.5mA while in operation.

Is it possible to modify this by turning off all BT and turn it to system on mode - halt mode? so that to turn it to a few uA current consumption.

Is it ture that once we download the softdevice to nordic, we cannot achieve uA level current consumption?

We have tried to download the RTC simple FW to dev board and our target. Both can get 10uA.

I am so confused why we cannot achieve a few uA current by stopping the BT.