From: ruston, matt ([email protected])
Date: Tue Jun 05 2001 - 07:23:22 PDT
Dori:
Hi. Yes, that termination is acceptable. The 1.5V supply is always sourcing
current (no need for a source/sink). This would be fine if you only had a
relatively small number of lines to terminate. If you had a lot of lines,
the drawbacks could be tough to swallow.
The drawbacks include a higher power consumed in the thevenin termination
(always drawing "idle" currents between 1.5V and ground) and it takes twice
as many resistors. The advantages are if you have a small number of lines,
you don't need to design any fancy (source/sink) power supply circuit.
If you want a 0.75V source/sink supply, look at what Synergy/Micrel have
done for SSTL2 termination supplies
(http://www.micrel.com/product-info/SSTL-Term.shtml). Maybe it can be
adapted for HSTL.
Later,
Matt
-----Original Message-----
From: Dori Itzhaki [mailto:[email protected]]
Sent: Tuesday, June 05, 2001 9:14 AM
To: SI List
Subject: RE: [SI-LIST] : HSTL Termination
Just making the subject clear :
Is the following termination solves the problem of source and sink current ?
Is that OK to use it with ordinary power supply ?
What are the drawbacks?
___ 1.5V
|
/
\ 100 ohms.
/
|\ \ |\
| \_____________|_| \
| / | | /
|/ / |/
\
/ 100 ohms
\
|
---
///
Thanks,
Dori Itzhaki
MystiCom Ltd.
**** To unsubscribe from si-list or si-list-digest: send e-mail to
[email protected]. 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
****
**** To unsubscribe from si-list or si-list-digest: send e-mail to
[email protected]. 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
****
This archive was generated by hypermail 2b29 : Thu Jun 21 2001 - 10:12:15 PDT