Multi-axis integrated inertial sensing device

A system comprising an integrated multi-axis MEMS inertial sensor architecture, the system comprising:

• a substrate member having a surface region;
• a CMOS IC layer overlying the surface region, the CMOS IC layer having a CMOS surface region, the CMOS IC layer having an Application Specific Integrated Circuit (ASIC) comprising:
• an Automatic Gain Control (AGC) loop circuit, the AGC loop circuit including:
• a rectifier,
• a proportional-integral-derivative (PID) controller electrically coupled to the rectifier,
• a comparator electrically coupled to the PID controller,
• a charge pump electrically coupled to the comparator, and
• a high-voltage (HV) driver coupled to the charge pump;
• wherein the rectifier's output is coupled to an input of the PID controller, the rectifier's input connected to an input of a comparator, where both the input of the rectifier and an input of the comparator are coupled to the output of a 90 degree phase shifter, wherein the input of the charge pump is coupled to the output of the PID controller, and the output of the charge pump is coupled to an input of the HV driver;
• a sense path having Charge Sense Amplifier (CSA_SNS), a Programmable Gain Amplifier (PGA1), a mixer, another Programmable Gain Amplifier (PGA2), a Low Pass Filter (LPF), an A/D converter (ADC), and digital processing circuits;
• a MEMS gyroscope overlying the CMOS surface region, the MEMS gyroscope electrically coupled to the ASIC;
• and
• a MEMS accelerometer overlying the CMOS surface region, the MEMS accelerometer being electrically coupled to the ASIC;
• wherein the Application Specific Integrated Circuit (ASIC) further comprises an input multiplexer coupled to the A/D converter (ADC), wherein the MEMS gyroscope and MEMS accelerometer are coupled to the input multiplexer, wherein the ADC is shared between the MEMS gyroscope and MEMS accelerometer via the input multiplexer;
• wherein out of plane sense signal plates are shielded with metal shield on sides as well as on layers below the sense plates.