A method for closed loop operation of a capacitive accelerometer includes applying a first drive signal V1 to a first fixed capacitive electrode and a second drive signal V2 to a second fixed capacitive electrode the first and second drive signals each having a periodic waveform varying in amplitude between zero and a maximum value Vref and sensing a displacement of the proof mass and applying pulse width modulation to the first and second drive signals with a constant frequency fmod and a variable mark/space ratio. The method also includes applying a voltage offset Vref/2 to the proof mass and applying the pulse width modulation such that the first and second drive signals have a waveform that varies so that when either one of the first and second drive signals is at Vref or zero the other drive voltage is at Vref/2.