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Design >> RF Design >> question about the analog comparator
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Message started by James Bond on Aug 28^th, 2007, 1:20pm

Title: question about the analog comparator
Post by James Bond on Aug 28^th, 2007, 1:20pm

Hi, all

I am trying to build an anolog comparator in 0.35um process. I suppose that this comparator can operate at high frequency, for example, a 100MHz triangle wave form and 30MHz sinusoid signal at the input. But the result seems that the comparator in 0.35um process is not that sensitive at this frequency, can anybody have done this before ? Please give some suggestions about how to build this comparator? Thank you very much.

James

Title: Re: question about the analog comparator
Post by carlgrace on Aug 30^th, 2007, 1:02pm

You can design a really fast comparator in 0.35 um. The fastest would be a cross coupled latch, if you can accept the large offset voltage. Otherwise use a latch with a linear, low gain amplifier in it. See the Razavi book on data converters for ideas. Also check out the JSSC.

Title: Re: question about the analog comparator
Post by James Bond on Aug 31^st, 2007, 2:22am

Hi, carlgrace,

I think the cross coupled latch circuit they all need a clock signal, which is not the case in my circuit.

I checked the Razavi book, which chapter do you mean 'data converters'?

Thank you very much.

James