滞回比较器

https://blog.csdn.net/qq_29545231/article/details/79096282

https://blog.csdn.net/qq_25164233/article/details/81145653

 也即当VIN>VrefH,Vout从Uz翻转到U-z;当VIN < VrefL,Vout从U-z翻转到Uz