Need help identifying capacitor small ceramic

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JW

Well-known member
Joined
Jun 8, 2005
Messages
1,100
Location
Portland USA
Hey folks,
I'm looking at a tiny little blue capacitor. It appears to be a little ceramic one. The only thing written on it is the number 22.
I'm assuming that's not a capacitor code, which many of these little guys have, because when I went to look up capacitor codes, I can't find any instances of capacitors that have a two digit code. So it's probably a 22pF? nF? .22uF? My radio shack capacitance meter won't register it. However, a nice big Wima .22uF registers fine. So I'm guessing it's smaller than that.

It's function was/is between pins 1 and 2 of an IC opamp.

 
Hi, wich opamp? or what are those pins doing?

It sound like a 22pF NPO cap, they are usually small and sometimes blue.

JS
 
It's a  LME49720.  It appears it's between the output and inverting input A

https://www.google.com/search?q=LME49720&client=firefox-a&hs=sEo&rls=org.mozilla:en-US:eek:fficial&channel=sb&tbm=isch&tbo=u&source=univ&sa=X&ei=En4bVKerOujUiwKTi4H4AQ&ved=0CEkQsAQ&biw=1122&bih=497#facrc=_&imgdii=_&imgrc=FOyLJGO33tUjqM%253A%3BqQwYgzV0lm8TlM%3Bhttp%253A%252F%252Fcircuits.datasheetdir.com%252F37%252FLME49720-pinout.jpg%3Bhttp%253A%252F%252Fwww.datasheetdir.com%252FLME49720NABD%252BOperational-Amplifiers%3B446%3B326
 
Seems to be unity gain stable, >40º I guess graph shows wired at unity open loop gain freq, could be better but the application notes shown some applications with Av=1 and capacitance in the feedback of 10p and 100p, so 22p is in the range shown by the data sheet. Use 22p cap, if you can get NPO/COG cap better.

JS
 
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