From: Tadashi ARAI (email@example.com)
Date: Thu Apr 06 2000 - 04:37:39 PDT
It often was occured such a reflection problem on daisy-chain
Use "H" topology to solve it.
Divide clock line with T junction at exact center of 8 loads, after that
devide again at exact center of each 4 loads, and after that devide at
center of each 2. The point is that each "branch" must be the same
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Tadashi Arai//Platform Developing Dept.,Desktop Prd Div. Fujitsu Limited
firstname.lastname@example.org TEL:+81-42-370-7624 Inagi-shi, Tokyo, Japan
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On Wed, 05 Apr 2000 11:15:04 -0700
Mail from email@example.com described as below:
> I have a 20in long 50MHz clock line which connected to 8 loads(5.5pF per
> load). (Vcc=3.3)
> I used daisy-chain to connect all loads but the waveform of the nearest
> receiver (respective to the driver) only swing between 1V and 2V. The
> waveform of the furthest receiver overshoot above 4V.
> I think reflection is the main reason and I had put an end termination
> there is no improvement for the nearest receiver waveform.
> Anybody have any ideal to solve this problem?
> I appreciate any advice or suggestions.
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