Aiming at the problem that traditional demodulation algorithm of MEMS gyroscope has poor anti-noise ability and consumes much hardware resources

a synchronous integral demodulation（SID） algorithm is presented for closed-loop measurement and control circuit of MEMS gyro

which realizes the demodulation output of driving/detecting signal. The third-order synchronous integrator forms the demodulator. Simulation and analysis show that SID has a faster response time

a lower noise level

and less hardware resource consumption. Based on SID algorithm

a digital closed-loop measurement and control system for MEMS gyro is established. In the drive loop

PLL and automatic gain control technology are used to achieve gyro constant-amplitude constant-frequency resonance. In the detecting loop

high order band-pass ΣΔ loop filters improves the bandwidth of gyro and responsiveness. The simulation results show that the gyro drive amplitude is 4. 738 μm

the start-up time is 0. 12 s

the detecting bandwidth is 200 Hz

and the SNR is up to 113. 2 d B.