I have Seeeduino Cortex-M0+, which is similar to Arduino Zero, both using Atmel SAMD21 MCU. It is powered from 12V battery directly to 12V PWRIN jack. Current draw for LED blink test is 18mA. I tried two low power libraries:
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. I've read posts about Arduino Zero running on 5mA from 12V input in low power. What else can I do in order to get the current closer to 5mA?
I did a few experiments with external DC/DC converters feeding 5V pin on Seeeduino Cortex-M0+ from 12V battery, bypassing its MP1496DJ-LF-2 power stage. Here are the results:
|DC/DC model||sleep current [mA]||LED blink current [mA]|
|MP1496DJ built-in baseline||12.7||18.0|