IC functioning

All frequent questions about ICs of all kinds, will be stored here.
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cacophony
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Post by cacophony »

How will you know if an IC is functioning or not using a DMM? Are there any ways on how to check it?

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bajaman
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Post by bajaman »

not easy to do, but if the IC op amp is in the circuit and you have the 9 volt power supply connected and turned on, measure the voltage at the output terminal of the op amp ( 2 terminals if dual op amp etc.) - it should read very close to 4.5v dc if the op amp is functioning correctly (assuming you have the correct passive components in place - if it reads 9v dc then you have a problem. :wink:
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cpm
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Post by cpm »

and then again....

how do you measure voltage without a DMM? :lol:

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Post by marshmellow »

Using the tools you were given by nature: tongue, wet fingers, ...
You will get better with more experience.

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lolbou
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Post by lolbou »

If it should read 4.5V, use a LED and resistor...

ex: a 2.2V:20mA LED with a 4.5V voltage supply should have a (4.5-2.2)/0.020 = 115 ohm resistor in series not to burn.

If the LED lights correctly, then you're close to 4.5V...
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