A novel ±0.5 V, high current drive, and rail to rail current operational amplifier

Abstract

A current operational amplifier (COA) with very high current drive capability is presented in this paper. The principle of operation of this unique structure is discussed, its most important formulas are derived and its outstanding performance is verified by HSPICE simulation in TSMC 0.18 lm CMOS, BSIM3, and Level49 technology. Owing to the elaborately arranged components, the proposed circuit demonstrates very high frequency bandwidth, extremely high CMRR, high output impedance, and true rail to rail output voltage swing range while operating at very low power supply of ±0.5 V. The interesting results such as current drive capability of ±1 mA, high output impedance of 5 GX, wide gain bandwidth of 220 MHz, extremely high output voltage swing of ±0.45 V, which interestingly provides the highest yet reported output voltage compliance for current mode building blocks implemented by regular CMOS technology, low static power consumption of 159 lW, and very high CMRR of 155 dB is achieved utilizing standard CMOS technology. Full process, voltage, and temperature variation analysis of the circuit is also investigated in order to approve the well robustness of the structure. The transient stepwise and sinusoidal response analysis is also done to verify the proposed COA stability.