Why is the current consumption in SYSTEM ON too high (>1mA)?

[Johnson]

I downloaded the power consumption example code to a nRF51-DK to measure the current consumption during SYSTEM ON and SYSTEM OFF state.

For the SYSTEM ON state, I used the "system-on-wakeup-on-rtc" code. The current consumption was 4.4 mA and 1.2 mA during the "normal" and SYSTEM ON states. I was expecting the current consumption to be in the order of uA during SYSTEM ON. I also changed the LF clock source to external 32.678 kHz but the result was same. I also tried the "system-on-wakeup-gpio" code and got the same results.

Any suggestions as to why the current consumption was quite high?

For the SYSTEM OFF state, I used the "system-off-wakeup-on-gpio" code. The current consumption was 4.4 mA and 0.2 uA during the normal and SYSTEM OFF state. The SYSTEM OFF current looked correct in this case.

[Hung Bui]

@Johnson: Please make sure you do a power reset before starting measurement. After programming the chip will stay in debug mode and that may consume about 1mA. The example you used was very old. Please try with our example in the lastest SDK, v9.0.

The rtc example in \examples\peripheral\rtc should only consume about 4-5uA when running (SYSTEMON mode).

[Johnson]

Thank you! I got 2-3 uA during SYSTEM ON after the power reset.