FreeLists / si-list / [SI-LIST] Termination resistance value for GTL+ bus

[Samuel Dadel <samuel_dadel@xxxxxxxxx>]

Hi! All,  I am new to transmission lines: so I would greatly  appreciate of 
someone could give me some leads on the following.  I am employing a dual-ended 
parallel termination scheme for a GTL+  bus. The driver has the capacity to 
sink 50mA. The Vol is .5 and  the Voh is 1.5, and the Vref is 1.0 [Nominal]. 
When employing  a 50ohm termination scheme I see a voltage swing of 1.15 Volts  
at the driver, with Vol gone down to 0.3 Volts. The nominal values

  are 1.5 and 0.5. I get bit errors, that go away when Vref

  is lowered to 0.8 Volts.

  Could this be a case of unmatched termination?  In addition: these is this 
additional equation that I   cannot relate to the characteristic impedance of 
the trace.  Iol[max] = .050 Amps.  Iol = Vtt - Vol / R[eff].  R[eff] = 1.5 - 
0.5 / .050 = 20 ohms.  For a dual ended termination scheme Rtt = 20 * 2 = 40 
ohms.Thanks,Daniel



---------------------------------
Do You Yahoo!?
Yahoo! Finance - Get real-time stock quotes

------------------------------------------------------------------
To unsubscribe from si-list:
si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field

or to administer your membership from a web page, go to:
http://www.freelists.org/webpage/si-list

For help:
si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field

List archives are viewable at:     
                http://www.freelists.org/archives/si-list
or at our remote archives:
                http://groups.yahoo.com/group/si-list/messages 
Old (prior to June 6, 2001) list archives are viewable at:
                http://www.qsl.net/wb6tpu