What would cause the op-amp to behave like this?

Thread Starter

ElectricMagician

Joined Jul 26, 2012
57
Hi Everybody

I'm experimenting with an inverting amplifier built around an LM386.
Vout should be Vin * -5. Vin is a 440 Hz Tone.

The output voltage is almost always Vin * 0.5, not Vin * 5!
If I increase input the voltage (~1.5v), the output is even less than half the input.

The circuit and the values are from my textbook. I checked multiple times that the circuit was constructed accurately. So, what would be causing this problem?

- Damaged or faulty op-amp?
- Op-amp unable to handle the 440Hz tone? (Datasheet says it's designed for audio amplification)?

Thank you very much.
 

timescope

Joined Dec 14, 2011
298
The LM386 is not an op-amp. It is an audio power amplifier designed to drive a speaker and has special circuits to keep the dc output at half of the supply voltage.
If you want to experiment with op-amps, use uA741, LM358, LF411 etc.

Timescope
 
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