A Practical Pll-Based Drive Circuit with Ultra-Low-Noise Tia for Mems Gyroscope

A novel phase-locked loop( PLL)-based closed-loop driving circuit with ultra-low-noise trans-impedance amplifier( TIA) is proposed. The TIA is optimized to achieve ultra-low input-referred current noise. To track drive-mode resonant frequency and reduce frequency jitter of actuation voltage,a PLL-based driving technique is adopted. Implemented on printed circuit board( PCB),the proposed driving loop has successfully excited MEMS element into resonance,with a settling time of 3 s. The stable frequency and amplitude of TIA output voltage are 10.14 KHz and 800 mVPP,respectively. With sense-channel electronics,the gyroscope exhibits a scale factor of 0.04 mV/°/s and a bias instability of 57.6°/h,which demonstrates the feasibility of the proposed driving circuit.