Re: The Criteria of overshoot, undershoot, RingBack for

Karthik Ethirajan (KarthikE@calmicro.com)
Tue, 08 Jul 1997 09:43:34 -0700

No part answers - generally system dependent.

Intel GTL+ requirements:
1. Intel uses controlled edge rate (~1nS)
2. Usually 5% tolerance pull-up termination in medium performance system; 1%
tolerance pull-up termination in high performance system

Use of proper termination strategy and a controlled impedance board solves a
great part of SI and EMI problems.

-Karthik
CMD

---------------------------------------------------------------------------------------------------
Karthikeyan Ethirajan
Applications Engineer (408) 934-3181

California Micro Devices 215 Topaz Street
karthike@calmicro.com Milpitas, CA 95035
----------------------------------------------------------------------------------------------------

>>> John Lin - TAO <LinJohn@mail.dec.com> 07/06 6:55 PM >>>
Hi ,

Talking about signal quality. Could somebody tell me about the criteria
of overshoot, undershoot, overshoot ring back, and
undershoot ring back for TTL(5V) , CMOS(5V), LVTTL(3.3V) logic types?

Intel has provided the GTL+ (Vtt=1.5V, Vref=1.0) criterion for signal
quality.
over/under shoot =0.2*(Vtt) ,
Ringback= Vref+/-200mv.

Best Regards,
JohnLin
CAE Engineer of the EDA Department.
DEC Taiwan Branch,
Email: Linjohn@mail.dec.com
TEL: 886-3-3900000 ext. 2565

JohnLin
CAE Engineer of the EDA Department.
DEC Taiwan Branch,
Email: Linjohn@mail.dec.com
TEL: 886-3-3900000 ext. 2565