Question
Why do gyroscopes like ADXRS290 consume much more power (7mA current at 3V supply) than accelerometer products like ADXL362 (3µA @ 400Hz ODRat 2V supply)?
Answer
MEMS gyroscopes have a resonating mechanical structure that is electrostatically driven to resonance. This produces the necessary velocity elementneeded to generate a Coriolis force on the structure when it experiences angular rate. The resulting Coriolis force generates motion in a directionnormal to the driven resonant motion, thereby being sensed by appropriately placed electrodes. Driving the MEMS structure into resonance requires ahigh voltage clock at the resonance frequency of the structure, which requires much larger power consumption than an accelerometer, where the MEMSstructure is static in absence of acceleration.