Robust implementation and statistical modeling of a VI-converter

A VI-converter is presented with adjustable transconductance suited for low-power operation through transistors biased in weak and moderate inversion. It can process unipolar differential input voltages or perform a correlated double sampling on a single-ended input signal. The influence of random device parameter variation is considered and a robust circuit topology is suggested which highly compensates it. The circuit is statistically characterized using variance calculation which requires much less computational effort than a Monte-Carlo analysis. The VI-converter is implemented in a 0.6 /spl mu/m technology on 48/spl times/90 /spl mu/m/sup 2/ silicon area. The maximum single-ended output current can be up to 1 /spl mu/A at 5 V supply voltage.