[SI-LIST] : Re: Charge moving from decoupling capacitors

About this list Date view Thread view Subject view Author view

From: Barry Ma (barry_ma@altavista.com)
Date: Thu May 18 2000 - 09:25:28 PDT


Vinu,

I am glad to hear of different opinion to my second question:
"Do we really have to limit the distance letting the charge have enough time to move from the cap to the chip during the rise time interval?"

You said: "The decap should be much closer than 0.5 Tr to be of use."

If Tr = 1 ns, the corresponding distance is approximately equal to 14 cm in FR4. There's no problem to locate decaps much closer than 7 cm, following your opinion. If Tr = 0.2 ns (likely happens in 5 - 10 years), it might be difficult to implement it - much closer than 1.4 cm. Then further Tr = 0.1 ns, ... much closer than 0.7 cm, and so on ... That's why I raised the question.

Can you detail your opinion? Thanks.

Barry Ma
bma@ANRITSU.com

_______________________________________________________________________

Why pay when you don't have to? Get AltaVista Free Internet Access now!
http://jump.altavista.com/freeaccess4.go

_______________________________________________________________________

**** To unsubscribe from si-list or si-list-digest: send e-mail to
majordomo@silab.eng.sun.com. 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
****


About this list Date view Thread view Subject view Author view

This archive was generated by hypermail 2b29 : Wed Nov 22 2000 - 10:50:24 PST