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| 一、简单电压比较器
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(1)当uI>UR时，u0为负向输出最大电压(-UOm)
(2)当uI<UR时，u0为正向输出最大电压(+UOm)
(3)UR=0，称为过零比较器
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具有输入保护和输出限幅的过零比较器 |
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| 二、具有滞回特性的比较器 |
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UB的值随输出电压而改变： |
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(1)uo为高电平时，uo=+Uz,
UB=UB1=uoR2/(R2+R3)=+FUz
(2)输出为低电平时，uo=-Uz,
UB=UB2=uoR2/(R2+R3)=-FUz
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传输特性： |
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1. uO为正，uI由负向正变化时，uI>UB1,
uO由正翻转为负；
2. uI由正向负变化时，uO为负，uI<UB2,uO由负翻转为正。
UB1、UB2称为门限电压。ΔU=UB1-UB2称为回差。R2和R3实现正反馈，正反馈加速了翻转过程使传输特性高低电位转换部分陡度增大。
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