i’ve written a program that puts the SAMD21 into a low-power suspend mode, where i then wakeup with a button press…
running that program on microchip’s SAMD21 XPLAINED board, my suspend current comes at ~3uA – consistent with the data sheet…
running the same program on the SAMD21-MINI, my suspend current is now >600uA… i am powering the board through the 3V3 VCC pin…
when in suspend mode, i do notice many of the pins (unsused by program) are outputing voltages that are definitely not zero… even the TX pin, which i’ve specifically placed in its “reset” state prior to entering suspend mode, is outputing 10s of mV…
as i keep staring at my program, is there anything in the SAMD21-MINI board design that might explain the 600uA of current when i’m in suspend mode???
full disclosure – i’m a SW type that can (sorta) read a schematic, but does know which end of the soldering iron to hold 