Introduction: The LM380N Audio Amp
I was a little intimidated by this IC the first time I looked at the datasheet because of all the ground connections. I thought it was a little silly. But after prototyping with this audio amp I don't think I'll ever go back to the LM386.
Step 1: Materials
1 10 ohm resistor
1 potentiometer between 1k and 10k, this is your volume knob so its really your choice.
2 470uF electrolytic capacitors
1 3.5mm audio aux jack
A power source, I'm using a 12.5 regulated power supply, you can go as low as 10 volts and as high as 22 volts. 8 AA batteries would run it nicely if you're looking to make it portable.
Step 2: The Circuit
First let's get all of those ground connections out of the way. Connect pins 3, 4, 5, 6, 7, 10, 11, and 12 to ground.
Then connect your positive power source to pin 14 through a 10 ohm resistor. And connect pin 14 to ground through a 470uF capacitor. The negative lead should be connected to the negative rail.
Now connect your common input of the 3.5mm jack to ground and the right and left both to the left pin of the potentiometer. The middle pin should be connected to pin 2 of the lm380 and the right pin should be connected to ground.
Now put a 470uF capactor from pin 8 to the positive terminal of your speaker (Negative lead of capacitor connects to the speaker) and the negative speaker wire should be grounded.
Step 3: The Schematic
This is not my schematic but this may be a little easier to follow.
Step 4: Conclusion
Try this circuit if you haven't before. I think you'll be pleasantly surprised. There's no feedback or crackling of any kind like I always get with the LM386. I will definitely be using these in more of my projects. I also ordered some more parts from digikey today so I may have more audio amps to come :) happy prototyping!
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