MOS variable gain amplifier for quartz gyroscope driving

This paper adopts single-stage amplifier and exponential gain control circuit to achieve gain variation. The single-stage amplifier uses improved Gilbert to increase the gain and bandwidth, and reduce the power consumption and voltage redundancy. The exponential gain control circuit based on corrected exponential function to approach ideal exponential function, and supply wide control voltage range. This paper based on 0.5μm CMOS process library, using Hspice and Cadence software to design and simulate the VGA. The system works at the 5V supply voltage, and when load capacitance is taken 5pF, the simulation results show that the VGA has 3MHz bandwidth, non-distortion control voltage range is 2.2V~2.7V, IIP3 is 11 dBm, gain dynamic range can reach -40dB~30dB. High gain dynamic range and high control voltage range are achieved in the paper.