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Design >> Analog Design >> CTLE vs DFE
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Message started by newic on Mar 18^th, 2012, 10:46pm

Title: CTLE vs DFE
Post by newic on Mar 18^th, 2012, 10:46pm

Is continuous time linear equalizer (CTLE) a FIR type while decision feedback equalizer (DFE) a IIR type?

what are the pros and cons between these equalizer?

Title: Re: CTLE vs DFE
Post by raja.cedt on Mar 19^th, 2012, 2:12am

hello CTLE is a continuous time filter, so don't cal it as FIR or IIR. DFE is an nonlinear means it has sampler in between, so even though it is digital it wont come under FIR and IIR. Mainly ctle is to equalize all kinds of cursors but DFE is mainly to compensate post cursor ISI without amplifying the noise where all other equalizer amplify the noise in general, crosstalk to be specific, but the problem with DFE is it can work in the links where the BER is already high (around 10^-10), otherwise it add more ISI in opposite to the reduction. This is called error propagation.

Please refer this website.

http://www.ece.tamu.edu/~spalermo/ecen689.html

Title: Re: CTLE vs DFE
Post by newic on Mar 21^st, 2012, 12:18am

From the link ppt slide, DFE is Feedback FIR filter...

Title: Re: CTLE vs DFE
Post by raja.cedt on Mar 22^nd, 2012, 2:07am

who said it is FIR....check slide 18 here http://www.ece.tamu.edu/~spalermo/ecen689/lecture8_ee689_rxeq.pdf

he is saying that DFE is composition of FIR and sampler. In fact now people are trying to implement with IIR in place of FIR