A Review of analysis of CMOS Current Mirror Circuits

A Current Mirror (CM) is one of the most imperative building blocks widely used for developing many analog/mixed mode Integrated Circuits. It is used for current amplification biasing and as active load in circuits like operational amplifiers operational trans-conductance amplifiers second generation current conveyers operational mirrored amplifiers current feedback operational amplifiers analog filters analog-to-digital and digital-to-analog converters etc. A CM when used as an active load helps to increase gain deprived of increase in power- supply power dissipation and chip area. It can copy a reference DC bias current across various circuit stages that can track changes in supply voltage or temperature. Thus it helps to reduce difficulty by removing the requirement of precision resistors external to chip. Also current amplification can be achieved by adjusting the aspect ratio of the MOSFETs forming primary CM pair. From now improving performance characteristics of a CM plays a vital role in deciding the overall performance of the CMOS circuits.