该文针对设计了一款基于解调信号相位矫正技术的低噪声微陀螺接口电路芯片。读出电路采用全差分跨阻放大器结构优化噪声性能,获得了0.63 aF/Hz的等效输入电容噪声。检测通路中采用双通道正交解调技术和解调信号相位矫正技术,完全消除了机械正交信号的干扰。芯片在0.35μm CMOS工艺下实现,与电容式微陀螺的联合测试表明,微陀螺系统的输入等效噪声为0.01o/s/ Hz ,在8.5 mV/o/s标度因子和5 V供电电压条件下,陀螺量程达到了±200o/s,线性度为2‰。
A low noise interface circuit on chip is designed for capacitive micro-gyroscope with demodulation signal phase calibration technique. Fully differential trans-impedance amplifier structure is adopted in the readout circuits to optimize the noise performance, which achieves an equivalent input capacitive noise of 0.63 aF/Hz . Dual channel quadrature demodulation technique and demodulation signal phase calibration technique are simultaneously applied to the sense channel, so that the interference of the mechanical quadrature signal is removed completely. The chip is implemented in 0.35 μm CMOS process. Experiments on a capacitive gyroscope show that an equivalent input noise of 0.01o/s/ Hz is achieved. Under conditions of 8.5 mV/o/s scale factor and 5 V supply voltage, the full scale range of the gyroscope reaches ±200o/s with only 2‰nonlinearity.