Electronics > Beginners
Understanding op amp circuit
(1/2) > >>
d4n13l:
Hi,

I'm starting with op amps, from the schematic, I get 0-1V from voltage divider, and I would expect to see the same voltage in the output of the op amp due to the negative feedback but it stays frozen at 1.9V no matter the +IN voltage. Could someone help me figure out why isn't it working?

rstofer:
Check the data sheet.  The op amp probably can’t work within a couple of volts of the rails.
Ultron81:
Yeah, what he rstofer said. If you want the input to drop to 0, you either need to supply a negative supply voltage to the op amp, or use a single-supply op amp that can go to 0V like a LM358.
d4n13l:
It worked with the LM358, I didn't know that not all op-amps can be used like that. Thanks :)
nigelwright7557:

--- Quote from: rstofer on July 24, 2019, 12:19:26 am ---Check the data sheet.  The op amp probably can’t work within a couple of volts of the rails.

--- End quote ---

Try a rail to rail op amp.
Not all op amps work close to the rails.
In fact some invert the output if close to the rails.
Navigation
Message Index
Next page
There was an error while thanking
Thanking...

Go to full version
Powered by SMFPacks Advanced Attachments Uploader Mod