capacitor to ground, and terminator models

Hello all
I am wondering about the use of the terminator model. I have a pair of
pins that can be used either as a differential PECL pair, as a single
PECL input, or as a single TTL input.

When used as a single PECL input, the non-inverting pin is decoupled to
ground through an externally connected 0.01uF capacitor in series. When
used as a single TTL input, the non-inverting pin is connected to
ground. My question is, when using the pair of pins in single sided
PECL mode, what should I use as the model for the pin decoupled to
ground? Should I use simply GND, or a TERMINATOR model?

ie:

[Pin]
.
.
.
|select pins 120 and 121 as either option A, B or C depending on which
mode
|the pair of pins are being used in.
|A: Differential PECL pair mode. (DEFAULT)
120 TRCLKP pecl06a_PECL2 NA 26.6nH 1.20pF
121 TRCLKN pecl06a_PECL2 NA 26.6nH 1.20pF
|
|B: Single sided PECL mode. TRCLKP decoupled to ground through 0.01uF
capacitor
| Note that input is now inverting.
|120 TRCLKP GND?? NA 26.6nH 1.20pF
 or
|120 TRCLKP PECLterm?? NA 26.6nH 1.20pF
|121 TRCLKN pecl06a_PECL1 NA 26.6nH 1.20pF
|
|C: Single sided TTL mode. TRCLKP connected to ground.
| Note that input is now inverting.
|120 TRCLKP GND NA 26.6nH 1.20pF
|121 TRCLKN pecl06a_TTL NA 26.6nH 1.20pF
|
.
.
.
Also, for TERMINATOR models, what exactly is required? are ground clamp
and power clamp tables required? are [Rgnd] and [Rpower] required? or
can I just simply list [Rac] and [Cac] (with NONE of [Rpower], [Rgnd],
ground clamp, or power clamp curves)?

thanx in advance,

roland

******************************************
Roland Chang ext. 2647

PMC-Sierra
Applications Department
105-8555 Baxter Place
Burnaby, BC
V5A 4V7
Tel: (604) 415-6000

email: chang@pmc-sierra.bc.ca
******************************************
 
Received on Wed Jul 9 16:01:14 1997