Hi,
We are wondering the current consumption in our custom board. The board has the following components (my FW view :)
nRF9160 - powered directly from batteries (either rechargeable ~4V or primary ~3.6V)
3.3V DCDC regulator providing power for these:
+ nRF9160 VDD_GPIO
+ nRF5340
+ Lis2DH accelerometer
+ W25Q80DV SPI flash
We have individual current measurement pads for all these components and I've used Nordic PPK2 to measure current consumption. We have trouble understanding why the design draw so much current while nRF9160 modem is idle.
My assumption is that we should be under 15uA, when nRF5340 is power off and accelerometer and flash are in low power state. Actually, there are some days when I have been able to see current consumption around 15uA, but usually with the same FW the board draws ~55uA. When we dig deeper, we notice that the extra 40uA goes to nRF9160VDD_GPIO. All other components draw as much as expected, including nRF9160 VDDH.
In addition, 55uA is not the current consumption soon after nRF9160 modem is powered off. After data transmission the current consumption is about 20uA higher and the consumption is gradually over about 10 minutes going down to 55uA.
Do you have any idea what could be causing the high current consumption?
Kind Regards,
Ilkka