Browse si-list: This Month's Archive • Main Archive Page • Related posts • Previous by Date • Next by Date

[SI-LIST] Re: SMD capacitor question

From: "Bart Bouma" <bart.bouma@xxxxxxxxx>
To: rvfm80@xxxxxxxxxxxx
Date: Mon, 2 Feb 2004 09:18:49 +0100

Hi Robert,
some additional notes to the answers of John (was there another reply
..... ;-) .

besides having piezo-effect - which indeed is neglectible for class-1 (C0G
or NP0) ceramic capacitors - ceramic capacitors also exhibit dielectric
absorption.
This also yields C0G capacitors, and there are large differences between
them. I have seen good ones, having DA-values below 0.01%, but also C0G
ceramic capacitors having DA-values of almost 0.5%.

Especially when using ceramic capacitors in fast settling filters or S&H
circuits, this DA-behaviour will be important too.
I recall a problem we had with a bluetooth-loopfilter using a C0G
capacitor, the radio ran out of spec (5-slot packet freq. drift over
40KHz).
Using another type of capacitor in this loopfilter solved the problem.

So, if this is important for you too, then look for ceramic capacitors
with low DA-values.
More information related to this can be found in an article written by Bob
Pease (understand capacitor soakage ..........):

http://www.national.com/rap/Application/0,1570,28,00.html

regards, Bart
appl. eng.
www.yageo.com

Dear fellow scientists/engineers:

We are pondering about using class 1 SMD ceramic capacitors in a loop
filter design. Does anyone know if class 1 capacitors have piezo-effect? I
don't even know what dielectric materials are used in those caps so any
info will be highly appreciated.

Best Regards,
Robert Tsai
------------------------------------------------------------------
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 technical documents are available at:
http://www.si-list.org

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

--------------------------------------------------------------------------------------------
The information contained in this communication is confidential and may be
legally privileged. It is intended solely for the use of the individual or
entity to whom it is addressed and others authorized to receive it. If you are
not the intended recipient you are hereby notified that any disclosure,
copying, distribution or taking any action in reliance of the contents of this
information is strictly prohibited and may be unlawful. YAGEO Corporation is
neither liable for the proper nor the complete transmission of the information
contained in this communication nor for any delay in its receipt.
---------------------------------------------------------------------------------------------

------------------------------------------------------------------
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 technical documents are available at:
http://www.si-list.org

[SI-LIST] Re: SMD capacitor question

Other related posts: