Low power mode for Seeeduino Cortex-M0+

I’m using Seeeduino Cortex-M0+ powered from 12V battery directly to 12V PWRIN jack. Current draw for LED blink test is 18mA. I tried two low power libraries:


  • LowPower.standby(); delay(5000);
  • Watchdog.sleep(5000);

In both cases, the current draw dropped only to 12.7mA, which is still huge. I checked the datasheet of MP1496DJ-LF-2 step-down, switch-mode converter used by this board and its quiescent current is below 1mA, so it doesn’t look like the source of high current consumption. On the other hand, CJA1117B-3.3 linear regulator has quiescent current up to 10mA, which seems to be the major contributor to the problem. I’ve read posts about Arduino Zero running on 5mA from 12V input in low power. Is there anything I can do in order to get the current closer to 5mA?

I also tested powering it from 5V battery pack directly to 5V pin. Low power current was 9mA, blink test 21.5mA.

I posted a similar question earlier at StackExchange. New user status doesn’t allow me to post more links here.