Continuous Time Interface for ±1.5 g Closed-Loop Accelerometer

A continuous time analog interface for a capacitive accelerometer element is implemented. The integrated part of the interface includes an oscillator and readout circuitry excluding a controller and references. For the realized sensor, the minimum equivalent acceleration noise density of 400 ng/radicHz is measured. A full scale acceleration of plusmn1.5 g and a signal bandwidth of 300 Hz is achieved. The closed-loop sensor is capable of surviving a shock condition.