The desire for portability of electronic equipment generated a need for low power systems in battery operated products like hearing aids, implantable cardiac pacemakers, cell phones, and hand held multimedia terminals. Current mirror is one of the most basic building blocks both in analog and mixed mode VLSI circuits especially for active elements like op-amps, transistors, current conveyors, current feedback amplifiers etc. In this work CMOS current mirror is proposed which shows improved performance over conventional CMOS current mirror in terms of input resistance, output resistance and power consumption. This proposed CMOS current mirror is used in designing of comparators which is also known as 1 bit analog to digital converter. Proposed CMOS comparator shows lower power consumption and better accuracy than existing circuits.