An Ultra-low-power Gain-boost Class-C Inverter and Its Application

A novel gain-boost class-C inverter is presented.Both input transistors of the class-C inverter mostly operate in the sub-threshold region,and thus the inverter can replace traditional OTA(Operational Transconductance Amplifier) to realize low power consumption.A gain-boost technique is adopted to increase the inverter DC-gain,and an on-chip body bias technique is proposed to improve the adverse effect of process and supply voltage variations within the inverter.Based on the proposed class-C inverter,a switched-capacitor integrator and an audio ΣΔ modulator chip are implemented in 0.13μm CMOS technology.