求助贴，关于运放结构实现的比较器功能

腐朽的青春99

参考国外的毕业论文设计，一个采用如图结构的电路，用于比较两个输入端电压的值，参考的文章比较的延时可以达到200ps,但是我仿出来数量级都差了好多，大概在几十个纳秒。开关电容结构的比较器由于采用了正反馈结构可以达到几百个ps，这种结构可能吗？如果不行的话，应该采用怎么样的结构，才能实现？求大神帮忙啊

feynmancgz

回复 1# 腐朽的青春99


    What is the application of your comparator ?
    Which kind of technology do you use ?
    Have you ever calculate the bandwidth of your comparator ?
    Is your application allowed to use dynamic comparator ?
    Have you considered preamp+latch structure ?

Timme

可以看看martin的模电，专门有一章讲比较器

腐朽的青春99

回复 2# feynmancgz

Thank you for the questions.The comparator is used to detect the two inputs' zero crossing point,which means the two inputs change their conditions that one is bigger than the other one to the opposite.The design is under 180nm technology ,which is longer than the original design.
The bandwidth is about 200M,with a load of 1pF capacitor.
In my application ,clock-controlled comparators can't be used ,which means dynamic comparator is not suitable.
You mentioned that pream+latch may be a good idea ,but does it work without a preset?

腐朽的青春99

回复 3# Timme


   Thank you

腐朽的青春99

回复 3# Timme


   Thank you

tideblue

200MHz带宽，时延有几十个ns?
你AC仿出来确定是200MHz？GBW?

腐朽的青春99

回复 7# tideblue


   GBW

tideblue

你M5/M6的size？
还有差分运放的bias current？

腐朽的青春99

回复 9# tideblue

M5 is sized to be 20x larger compared to M6 in order to minimize the delay
of the ZCD. The transconductance of M5 is much larger compared to that of M6