Re: [SI-LIST] : pecl termination

About this list Date view Thread view Subject view Author view

From: D. C. Sessions (dcs@lumbercartel.com)
Date: Wed Jun 06 2001 - 06:31:03 PDT


On Wednesday 06 June 2001 05:25, Binoj G. S. wrote:
                
> I am using a differential pecl to ttl and ttl to differential pecl translator in my design in which the differential pecl o/p is using to drive one fo transceivers(hfbr 5903).As the fo transceiver i/p are in a different level I used capacitor coupling and biased the differential o\p at the fo i/p side.what I did is, biased the lines to middle of fo i/p (1.96v) with a thevenin termination which provides a 50 ohm impedance.
> But what I read is that the termination voltage should be vcc-2,i.e. 1.3v(3.3-2).How can I satisfy both of this condition or I am doing something false?The fo I/p levels are as follows
> vil min-1.49v vil max-1.825 vih min-2.135 vihmax-2.42

The termination to VCC-2 is in the context of open-source drivers
(ECL open emitters, NMOS open sources, or PMOS open drains.)
In your case, you want to terminate to VCC-1.32 volts which is
the center of the common-mode range.

-- 
| I'm old enough that I don't have to pretend to be grown up.|
+----------- D. C. Sessions <dcs@lumbercartel.com> ----------+

**** To unsubscribe from si-list or si-list-digest: send e-mail to majordomo@silab.eng.sun.com. In the BODY of message put: UNSUBSCRIBE si-list or UNSUBSCRIBE si-list-digest, for more help, put HELP. si-list archives are accessible at http://www.qsl.net/wb6tpu ****


About this list Date view Thread view Subject view Author view

This archive was generated by hypermail 2b29 : Thu Jun 21 2001 - 10:12:16 PDT