Abstract
This paper presents a continuous-time current comparator with low input impedance enhancing the accuracy of comparison. The proposed circuit employs low impedance common-gate structures as input stages and further uses common-source feedback structures to enable extremely reduction of input impedances. The input impedances are well designed to be balanced, so that the proposed design can be applied to perform precise comparison between two terminals with tiny varied currents. An implemented chip was fabricated by TSMC 0.35µm CMOS process with its input impedances and propagation delay are 66.8Ω, 66.6Ω and 2.5ns respectively while the average power consumption is about 1.64mW.
