Quadrature ADC feedback compensation for capacitive-based MEMS gyroscope

A method of compensating rate offset of a micro-electromechanical systems (MEMS) gyroscope, comprising:

• generating, by a drive circuit coupled to a resonating element, an analog drive signal for driving the resonating element into resonance;
• generating, by a sense circuit coupled to the drive circuit and the resonating element, an analog rate signal and an analog quadrature signal in response to a change in capacitance output by the MEMS gyroscope;
• converting, by one or more analog-to-digital converters coupled to the sense circuit, the analog rate signal and the analog quadrature signal into a digital rate signal and a digital quadrature signal, respectively;
• nulling, by a compensation circuit coupled to the sense circuit, the analog quadrature signal using the analog drive signal and a compensation value;
• and
• adaptively compensating, by a digital processing circuit, a quadrature-induced rate offset of the digital rate signal over temperature using the digital quadrature signal, the compensation value and temperature data.

An electronic system comprising:

• a drive circuit configured to generate an analog drive signal for driving a resonating element into resonance;
• a sense circuit coupled to the drive circuit and the resonating element, the sense circuit configured to generate an analog rate signal and an analog quadrature signal in response to a change in capacitance output by a MEMS gyroscope;
• and
• one or more analog-to-digital converters coupled to the sense circuit and configured to convert the analog rate and analog quadrature signals into digital rate and digital quadrature signals, respectively;
• a compensation circuit coupled to the sense circuit and configured to null the analog quadrature signal using the analog drive signal and a quadrature compensation value;
• and
• a digital processing circuit configured to adaptively compensate quadrature-induced rate offset of the digital rate signal over temperature using the digital quadrature signal, the quadrature compensation value and temperature data;
• one or more processors;
• memory coupled to the one or more processors and storing instructions that when executed by the one or more processors, cause the one or more processors to perform operations comprising:
• obtaining the digital rate signal;
• calculating orientation data of the electronic system using the digital rate signal;
• and
• providing the orientation data to one or more client applications or electronic system components.