Operational Amplifier Design Employing DTMOS Technique with Dual Supply Voltages

Abstract

An operational amplifier (OPAMP) for portable devices with dual supply voltage is presented in this work. The design is realized with a 600[Formula: see text]mV supply for the core design and a 1.8[Formula: see text]V supply for the biasing circuit to improve input common mode range (ICMR), gain, and common mode rejection ratio (CMRR). The designed amplifier is implemented with dynamic threshold voltage MOSFET (DTMOS) transistors to decrease power consumption and increase the performance of the design. The power consumption of the core design is obtained as 2[Formula: see text][Formula: see text]W while the biasing circuitry consumes 7.38[Formula: see text][Formula: see text]W. The application of different supply voltages has greatly increased the gain of the circuit, where the circuit exhibits 100.2[Formula: see text]dB DC gain and 3.41[Formula: see text]MHz gain bandwidth product (GBW). CMRR of the designed circuit is 84.22[Formula: see text]dB. The simulations are performed in Cadence environment with 0.18[Formula: see text][Formula: see text]m CMOS technology.