I have designed a PCB where I am using the MMA8452Q accelerometer.
Because it is a battery powered device, we want to ensure that we are using the lowest sleep current states of all the components on board.
However, while testing we noted that the accelerometer is still consuming ~30 uA of current in system sleep state, even though firmware has put it in low power mode with ODR of 12.5 Hz. In our application, we just use INT1 to identify any interrupt and convey it to the MCU whenever set orientation threshold is crossed.
I have a couple of queries:
I have decoupled VDD (pin 14) with 0.1 uF and VDDIO (pin 1) with 4.7 uF. Datasheet suggests the opposite. Can that be a reason for the heightened current in low power mode?
SA0 (pin 7) is hard-wired to GND. Is this affecting the quiescent current in low power state? Maybe there's an internal connection in the chip to some power rail which is creating a current flow path.
Any help would be appreciated.
