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Design >> Analog Design >> Two-Stage Open-Loop Comparator in Allen’s Book
https://designers-guide.org/forum/YaBB.pl?num=1184298007

Message started by qiushidaren on Jul 12^th, 2007, 8:40pm

Title: Two-Stage Open-Loop Comparator in Allen’s Book
Post by qiushidaren on Jul 12^th, 2007, 8:40pm

Hi all,

Table 8.2-2 of Allen’s book <<CMOS Analog Circuit Design>> gives us a procedure to design a two-stage open-loop comparator for a linear response, in step 3, there is a equation I5=I7(2CI/CII), but I really don’t know how and from where can I derive it, your suggestions and time will be highly appreciated.

Rgds,
Terry

Title: Re: Two-Stage Open-Loop Comparator in Allen’s Book
Post by skythunder on Jul 18^th, 2007, 12:26am

I think I got it .
P1=P2; P1=(gds2+gds4)/C1=2*a*Id2/C1=Id5*a/C1;P2=(gds6+gds7)/C2=2*a*Id7/C2 (a means the parameter LAMDA)

then you can get the I5=I7*2*C1/C2
regards ;)

Title: Re: Two-Stage Open-Loop Comparator in Allen’s Book
Post by qiushidaren on Jul 18^th, 2007, 7:40pm

Yes you are right, thank you so much.

-Terry

Title: Re: Two-Stage Open-Loop Comparator in Allen’s Book
Post by skythunder on Jul 18^th, 2007, 8:25pm

Hi, qiushidaren,

since we are both reading allen's book, the only difference is that you are focusing on the comparator, while I am working on the switched capacitor circuits. Can you give me some comments on my post just below your post, about the high Q SC biquad question ? I have been troubled by the circuit for a long time. Here is the link to my psot

http://www.designers-guide.org/Forum/YaBB.pl?num=1184741812

Thank you ! :)