宽输入共模范围电压比较器的设计

Design of Voltage Comparators with Wide Input Common-Mode Range

当输入信号的共模值超过或者接近电源电压时，传统的电压比较器就会出现不足，因此有必要设计新的比较器来实现对高共模信号的检测。采用了共栅差分输入级，极大地增加了输入共模信号的范围。基于此输入级设计了两个电压比较器，一个在锂电池充电电路中实现了对电池和电源电压的监控，另一个响应速度快。CSMC0．6μm CMOS工艺的仿真结果表明，前者能简便的实现输入失调和迟滞控制功能，静态电流仅为1．2μA；后者在单电源5V下输入共模范围是1.3-15V，在10mv的过驱动电压下，延时为11ns，静态工作电流为91μA。

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 commonmode signals. A common-gate 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 CSMC 0.6 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.