Author Topic: Faulty op-amp?  (Read 833 times)

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Offline JoePTopic starter

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Faulty op-amp?
« on: March 01, 2019, 11:04:00 pm »
I'm trying to use an op-amp in an amplifier circuit (the LM324N), but it doesn't seem to be working properly. From a 5V power supply, I measured the non-inverting input at 2.5V, the inverting input at 0.8V and the output at 3.9V. Shouldn't the output be at the full 5V? I haven't used op-amps much, so it might just be a simple mistake with the circuit, which I'll attach later.
 

Offline radix

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Re: Faulty op-amp?
« Reply #1 on: March 01, 2019, 11:11:26 pm »
The ancient LM324 can't get its output near the rails. If you look at the datasheet, you'll see that the output swing is specified at approximately 2 V less than the supply voltages. Use a better opamp with a rail to rail output.
 
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Offline Siwastaja

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Re: Faulty op-amp?
« Reply #2 on: March 02, 2019, 01:12:26 pm »
Or, increase Vcc.
 


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