Subject: Pulldown for ECL...

From: R Sanjeev <[email-masked]>
Date: Thu, 8 May 1997 17:21:44 +0531

Hello,

The specs says that in case of ECL (VCC +ive voltage supply and VEE -ve
voltage supply ) both the pullup and the pulldown are made with
reference to VCC and we require to use:

Vtable = VCC - Vout. in BOTH cases.

This makes sense as in case of a differential pair the same stage will
do the pullup and the pulldown.

So from my understanding of the specs the Voltage values of the
Pullup/Pulldown tables in case of Output_ECL should be the same.eg
VCC = 0V and if I simulated Vout for 0 to -2.2V in both cases.
The Table should look like:
2.2	x x x
2.1     x x x
.
.
.
0.0     x x x

Is this correct?

I'm unable to cross check with s2ibis as s2ibis2.1 does not seem to be
able to handle Output_ECL when it comes to the [Pulldown] it has put
some wierd values. In case of pullup the voltage in the *spi files have
been varied from VCC to VCC-2.2 volts and the output in Vtable also
followes VCC-Vout.  ( And also filled the ibis file with lines of 0.0
0.0 0.0 0.0 after that)

The [Pulldown] has been simulated from VCC to VCC-2.2 volts but these
values have not been used to fill the table. Voltage column is filled
with 0 and -0.1 in the Voltage column.  
Could someone please comment on this too.(maybe Alan Glaser if he is
free)

Thanx in advance,
regards,
presi