Patent ID: 9116164
Filing Date: 2015-08-25
Classification: G01D,G01L,G01P,H01L

Abstract:
1. A pseudo-differential accelerometer resistant to electromagnetic interference, the pseudo-differential accelerometer comprising: a microelectromechanical device including a capacitive sensor core having a first sensor core input, a second sensor core input and a sensor core output; an integrated circuit including a chopper system, a differential amplifier, a dummy core and a reference voltage, the integrated circuit being coupled to the microelectromechanical device by bond wires; a sensor core bond wire coupling the sensor core output of the capacitive sensor core to a sensor core chopper input of the chopper system; a first feedback bond wire coupling a first feedback signal to the first sensor core input of the capacitive sensor core, the first feedback bond wire being coupled to a first chopper feedback output; and a second feedback bond wire coupling a second feedback signal to the second sensor core input of the capacitive sensor core, the second feedback bond wire being coupled to a second chopper feedback output; wherein when the chopper system is in the chop state 0 , the chopper system connects the sensor core chopper input to the inverting input of the differential amplifier, connects the dummy core chopper input to the non-inverting input of the differential amplifier, connects the first chopper feedback output to a difference of the amplifier output and reference voltages, connects the second chopper feedback output to a sum of the amplifier output and reference voltages; and when the chopper system is in the chop state 1, the chopper system connects the sensor core chopper input to the non-inverting input of the differential amplifier, connects the dummy, core chopper input to the inverting input of the differential amplifier, connects the first chopper feedback output to the inverse of the difference of the amplifier output and reference voltages, connects the second chopper feedback output to the inverse of the sum of the amplifier output and reference voltages, the inverse of the difference of the amplifier output and reference voltages having the same magnitude and opposite polarity as the difference of the amplifier output and reference voltages, and the inverse of the sum of the amplifier output and reference voltages having the same magnitude and opposite polarity as the sum of the amplifier output and reference voltages.