Idle current consumption

[mich_x]

What is the current consumption of nRF52480 when idle.

I used power profiler to measure it. But I want to know if it is accurate.

[Sigurd]

Hi,

Are you measuring the System ON, No RAM retention, Wake on any event current ? For the nRF52832 this is 1.2 µA. For the nRF52840 you should see a lower number here.

What did you measure ?

[mich_x]

I am not sure. Basically, I am using the ble_app_uart_c example. And the idle current I measured using power profiler is 0.9mA. Is it somehow too big?

[Sigurd]

Hi,

If you close the UART(E) with app_uart_close(), and stop the scanning(comment the scan_start();, or call sd_ble_gap_scan_stop()) you should see a couple of µA power consumption.

Note that you on the nRF52840-PDK need to cut both SB40 and SB41 to get accurate current measurements.

Note, you need to power cycle the UARTE peripheral after you call app_uart_close() in order stop HFCLK and DMA bus. See this post

So you need to do it like this when you close the UARTE:

err_code  = app_uart_close();
*(volatile uint32_t *)0x40002FFC = 0;
*(volatile uint32_t *)0x40002FFC;
*(volatile uint32_t *)0x40002FFC = 1;

Also remember to disable the log module in sdk_config.h (set NRF_LOG_BACKEND_RTT_ENABLED and NRF_LOG_ENABLED to 0)

[mich_x]

Really? SB40 and SB41? I only cut SB40 but already got a relatively clean figure.

[mich_x]

I have stopped the uart and the LOG and the scan. I measured again and got a periodic wave. The highest current is 70uA and the lowest is 40uA. And the cycle time is about 50ms. Do you maybe have any idea of what causes this wave? I have commented out everything else. This is my whole program.

   for (;;)
{
	nrf_pwr_mgmt_run();
}