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Choice and Number of Caps for min noise - RF Cafe Forums
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Below are the old forum threads, including responses to the original posts.
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Post subject: Choice and Number of Caps for min
noise Posted: Mon Aug 04, 2008 7:48 am
Tue Feb 27, 2007 6:16 am
I wish to be
able to determine the minimum number of capacitors required and typical
values to be used on the input and output of a voltage regulator, to
achieve a desired noise ripple (and a minimum amount of soldering).
Can anyone recommend a well explained decent text?
Regards, Darcy Randall, Perth, Western Australia
Post subject: Linear regulatorsPosted:
Mon Aug 04, 2008 9:48 pm
Joined: Sat Apr
22, 2006 11:14 pm
Have you looked through App notes
at Linear technologies and Analog Devices? I'd start from there.
Post subject: Posted: Thu Aug
07, 2008 4:27 pm
Joined: Mon Jun 27, 2005
For most of the regulators a single capacitor is required at the input
and 1-2 are required at the output. The capacitors should have the right
ESR (Not too high - ripple, but also not too low - for stability), the
right technology (Usually X7R, X5R) for temperature stability. In the
device's data sheet, there are usually recommendations for the capacitance
value and the required ESR.
Hope this helps.