Signal-dependent clock-feedthrough cancellation in switched-current circuits

Abstract

The authors have developed three schemes for cancelling the signal-dependent clock-feedthrough in switched-current circuits. Two of the schemes are based on replicating the current track-and-hold to produce an output current with less than 0.03% THD for a signal to bias current ratio of 0.5 and current mirror sizes of W/L=20 mu m1/2 mu m. In the third scheme, by adapting the clock signal to the signal level, a constant clock-feedthrough is produced. All of the cancellation schemes presented have been integrated in a 2 mu m CMOS process.<>