Design of an accurate min-max current selector

An accurate min-max current selector is designed and simulated. Given two input currents, it sorts them so that a copy of the smaller of the two input currents appears at one output, and a copy of the larger input current appears at the other output. The min-max current selector operates for input currents ranging from 70 μA to 90 μA, that is, over a range of 20 μA. It has been designed and simulated for a 1.2 μm standard CMOS process. The worst case difference between an input current and its corresponding output current is 10 nA. The min-max current selector makes use of a specially designed current comparator with a maximum input offset current of 5 nA and a differential gain of 2.025 V/nA.