Simple Technique to Improve Essentially the Performance of One-Stage Op-Amps in Deep Submicrometer CMOS Technologies

Abstract

A comparative study of one-stage-amp performance improvement based on simulations in 22 nm, 45 nm, 90 nm, and 180 nm in deep submicrometer CMOS technologies is discussed. Generic SPICE models were used to simulate the circuits. It is shown that in all cases a simple modification using resistive local common mode feedback increases open-loop gain and gain-bandwidth product, peak output currents, and slew rate by close to an order of magnitude. It is shown that this modification is especially appropriate for its utilization in current CMOS technologies since large factor improvements were not available in previous technologies. The OTAs with resistive local common mode feedback require simple phase lead compensation with a very small additional silicon area and keep supply requirements and static power dissipation unchanged.

Keywords

• resistive local common mode feedback
• class AB CMOS op-amps
• mixed-signal circuits