基于CMOS反相器的脉冲窗口比较器

Pulse Window Comparator Based on CMOS Inverter

传统利用两个单限比较器实现窗口比较器的方案电路结构较复杂,且同时只能输出一个极性的脉冲,设计一种新颖的基于CMOS反相器的脉冲窗口比较器,窗口比较器只用了三个CMOS反相器、二个电阻、二个预置电位器和一个开关二极管,根据CMOS反相器的阈值电压通常大致为高阈值≥0.7Vcc,低阈值≤0.2Vcc、即输入低电平的上限0.2Vcc,输入高电平的下限0.7Vcc的特性,利用反相器N1的输出能否反转,从而使反相器N2、N3的输出反转,从而实现“脉冲窗口”。

The traditional scheme of using two single-limit comparators to realize window comparator has complex circuit structure and can only output one polar pulse at the same time.A novel pulse window comparator based on CMOS inverters is designed.The window comparator only uses three CMOS inverters,two resistors,two preset potentiometers and one switch diode.According to the characteristics of CMOS inverters such as high threshold voltage≥0.7Vcc,low threshold≤0.2Vcc,that is upper limit of input low level 0.2Vcc and lower limit of input high level 0.7Vcc,it can invert the output of inverters N2 and N3 by using the output of inverters N1,thus realizing"pulse window".