Design of Voltage Comparators with Wide Input Common-Mode Range
Yiqiang Wu · Semiconductor Technology · 2007
When the input common-mode signals exceed or approach the supply voltage,shortcomings of traditional voltage comparators will emerge.It is necessary to design a new comparators to sense high common-mode signals.A commongate input stage was adopted,which largely extends the range of the input commonmode.Base on this input stage,two comparators were designed.The supply and Li-ion battery voltage in the Li-ion battery charge circuits were monitored by one,the other response speed is high.Simulation in CSMC0.6 μm CMOS process shows that the former can implement the input offset and hysteresis easily,and the quiescent current is only 1.2 μA.The input common-mode range of the latter is 1.3 to 15 V with a single supply voltages of 5 V.Its propagation delay is 11 ns with a 10 mV overdrive and quiescent current is 91 μA.