Design of Hysteresis Comparator with Wide Common Mode Operating Range

In order to improve the ability of hysteresis comparators to suppress noise and interference signals and expand their common mode operating range, an improved hysteresis comparator circuit is proposed based on the analysis of the relationship between input common mode range, the tail current and the flip voltage, utilizing the common mode signal to realize adaptive bias of tail current transistor. Using SMIC 0.18$\mu$m 1P6M CMOS technology, the simulation results show that when supply voltage is 1.8V, 2.2V and 2.8V respectively, the proposed hysteresis comparator can work normally under the input common mode voltage changes from 0 to 1.5V at five process corners (TT, SS, FF, FS and SF).