On the power efficiency of cascode compensation over Miller compensation in two-stage operational amplifiers

Abstract

Optimization of power consumption is one of the main design challenges in today's low-power high-speed analog integrated circuits. In this paper, two popular techniques to stabilize two-stage operational amplifiers, namely Miller and cascode compensations are compared from power point of view. To accomplish this, the cascode-compensated structure is basically analyzed to derive the required equations for comparison. The results show that for the same specifications, cascode compensation is more power efficient than Miller compensation especially for heavy capacitive loads. This has been confirmed by circuit-level simulations in 0.25 μm CMOS technology.