INTEGRATED INERTIAL SENSING DEVICE

摘要

A system can include a MEMS gyroscope having a MEMS resonator overlying a CMOS IC substrate. The CMOS IC substrate can include an AGC loop circuit coupled to the MEMS gyroscope. The AGC loop acts in a way such that generated desired signal amplitude out of the drive signal maintains MEMS resonator velocity at a desired frequency and amplitude. A benefit of the AGC loop is that the charge pump of the HV driver inherently includes a ‘time constant’ for charging up of its output voltage. The system incorporates the Low pass functionality in to the AGC loop without requiring additional circuitry.

主权项

1. A system comprising an integrated MEMS gyroscope 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 Automatic Gain Control (AGC) loop circuit, the AGC loop circuit including a rectifier, a comparator, a proportional-integral-derivative (PID) controller, a high-voltage (HV) driver, a charge pump, a sense path having a 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; and a MEMS gyroscope overlying the CMOS surface region, the MEMS gyroscope electrically coupled to the AGC loop circuit.