A 1.5 v High Swing Ultra-Low-Power Two Stage CMOS OP-AMP in 0.18 µm Technology

A High Swing Ultra-Low-Power Two Stage CMOS OP-AMP in 0.18 μm Technology with 1.5v supply, is presented.Topology selection and theoretical analysis of the design are discussed. Cascode technique has been used to increase the dc gain. The unity-gain bandwidth is also enhanced using a gain-stage in the Miller capacitor feedback path. The proposed opamp provides 236 MHz unity-gain bandwidth, 81.3 degree phase margin and a peak to peak output swing 1.26 v. The circuit has 92.5 dB gain and slew rate is 16.75 v/μs . The power dissipation of the designed only is 50 μw. The designed system demonstrates relatively suitable response in different temperature.

I. Introduction

Research in analog-circuit design is focused on low-voltage low-power battery operated equipment to be used as an example in portable equipment, wireless communication products, hearing aids, and consumer electronics. A reduced supply voltage is necessary to decrease power consumption to ensure a reasonable battery lifetime in portable electronics. For the same reason, low-power circuits are also expected to reduce thermal dissipation, of increasing importance with the general trend in minimization. Advancements required by International Technology Roadmap for Semiconductors (ITRS), means that with current CMOS standard fabrication processes, circuits must work at supply voltages as low as 1.5 V. Working at lower voltages poses new constraints, especially important for the specific case of analog design. However, a reduction in performance is not desirable. Nevertheless, going to lower voltages and higher efficiencies require innovative circuits to solve current design needs of faster circuits and better performance [1].