RE: PAM-5, what are your BERs ?
JR -- my semi-biased view:
i contend it can be built in any manufacturing technology that will
deliver the performance required at the cost target you like. a 5-PAM
receiver built of monolithic CMOS can do that nicely, when feature
size is on the order of 0.18um to 0.25um, and there are more than
a few foundry service houses that can offer that geometry scale
(which is a critical concern for 'fabless' semiconductor houses).
BiCMOS and GaAs both outperform CMOS at the serial line rate,
but neither of them is as widely available nor can they compete as
well in complex back-end signal processing functions -- equalization,
error correction, general DSP.
it is my impression that many new products start in one technology
(probably for "time to market" issues) but eventually wind-up in CMOS.
finally, there are probably many ways one can build a fast ADC but
the more difficult challenge -- for 10Gbd x-PAM -- is in building a fast,
linear DAC.
and now, back to morning coffee...
--
J M Wincn
P O Box 631
Cupertino, CA 95015-0631
Email: jmw@xxxxxxxxxxx
Voice: 408-725-0846
Fax: 408-873-0293
Cell: 408-394-5283
At 06:02 PM 29-02-2000 -0800, JR Rivers wrote:
>Not to throw water on an oil fire, by why does the transceiver have to be
>CMOS? If my memory serves me correctly, most of the SERDES devices used in
>GE were BiCMOS or GaAs until recently.
>
>JR