A Low-Voltage Hybrid CMOS-Memristor-Based Wideband Class-AB Amplifier for Portable Electronic Device Applications

Abstract

This paper presents a low-voltage high-gain wideband three-stage true-class-AB amplifier. This is realized in the 0.18 μm CMOS process. The three-stage class-AB amplifier is proposed based on a compensation topology called nested Miller compensation along with a memristor to get pole-zero cancellation, which arises beyond the unity gain frequency. The circuit is implemented without the need for extra components as transistors, resistors, and capacitors, thus saving the complexity of the circuit and power consumption. The circuit is designed to operate with a supply voltage of ±1 V along with a bias current of 175 μA. The simulation results indicate that this proposed amplifier is capable of driving wide range of resistive and capacitive loads, furthermore capable of maintaining a phase margin of more than 60°. The total compensation capacitor is 2 pF, which is much lesser as compared to pseudo- and true-class AB amplifier, which implies a reduction in area. Simulation results show that the unity gain frequency of the proposed class-AB amplifier is 136.7 MHz, which is much higher as compared to the counterpart topologies. The major advantage associated with this work is a very high bandwidth attained without affecting the gain of the amplifier.