LM386 audio amplifier circuit with PCB

Though LM386 audio amplifiers are very old. But they still have a lot of useful.

Thanks, designer.

Imagine your audio player is weak sound. You want to increase sound up. They are a good choice. Because of the low voltage supply and work well with a battery.

LM386 Datasheet Low voltage audio power amplifier

LM386 Datasheet

You finished an audio circuit. But the sound is too weak.

Many people use LM386 to increase sound up to a speaker. Why should you do it too? Some said to try it now.

But…it is better. If you read LM386 Datasheet before.

LM386 is a low voltage audio amplifier. And, good at working with a battery. Its shape is similar for IC-741, DIP-8. So, small and easy. Even small but great sound.

LM386 in DIP-8 packet
LM386 low voltage amplifier on DIP-8 packet

Cr: LM386 of National Semiconductor. I like it.

LM386 Pinout

LM386 Pinout and Internal structure

Often we use LM386 in DIP-8. Which there are a few pin connections.  Even other packets are the same. For example, SOP-8, TSSOP-8, etc.

See LM386 Features

  • Give enough power—Common Power of the output is about 700mW at VS=9V, RL=8Ω, THD=10%. Imagine you can listen to soft music at prefer corner.
  • Use Wide supply voltage range of 4V to 15V.
  • Use low supply current—if no input signal is approx 4mA or max 8mA.
  • Internal voltage gain set to 20 or 26dB. (without other parts)
  • The more voltage gain to 200 or 46dB. When we connect a 10uF capacitor across pin 1(+) and pin 8(-).
  • And, we may use a resistor in series with the capacitor. To reduce the gain between 20 and 200.
  • Low harmonic distortion: 0.2% typical
  • Frequency bandwidth: 300kHz in typical

With a lot of their benefits. A lot of electronic appliances have it to drive the speakers. Example for, radio, MP3 player, Mini Portable speaker, Etc.

More circuit more understand

My brain is slow. I cannot understand any information fast. Has this happened to you?

I have used images. They help me understand anything more.

Also, I like the circuit diagram and circuits. I see and learn and get many ideas from it.

So, let’s see more LM386 circuits.

x20 Amplifier

x20 amplifier using LM386

The smallest amplifier gives a gain of 20 with the least parts.

It is true. It is an amplifier circuit. Even there are one IC and one capacitor only.
And, It uses low current at the output.

But In real usage. You need a louder of sound. How do you do? You can do it in a simple way. Below.

X200 great small amplifier

How to increase gain of LM386

In the circuit. The gain of circuit rise up to 200. Because we place the Capacitor-C2 to the IC. Connect the positive leg of C2 to Pin 1. And, the negative leg to Pin 8.

But sometimes high gain is not good for us. We can do too.

X50 lower gain of LM386 amplifier

Reduce the gain to 50 with resistor and capacitor


We add another one resistor-R2 in series with C2. To reduce the gain to 50.

LM386 Amplifier with bass boost

LM386 Amplifier with bass boost

Sometimes you may want a special bass. We also can do. Easy…with adding one resistor and one capacitor only. See in the circuit. The R2 connects with C2 in series.

This circuit is a bass booster. The output gain depends on a bass frequency. For example, Gain 25dB: 100Hz, and Gain 19dB: 2kHz.

Almost forgot some components on every amplifier above have important.

  • We can adjust the volume by VR1.
  • Both R1 and C3 will keep a good sound. They improve a high-frequency load for stability.

Do you know we can do other circuits with LM386?

Yes…

LM386 Square wave oscillator

LM386 Square wave oscillator

We will see a square wave oscillator circuit. Also, we can create it is audible alarms on the speaker. Because this IC is on type of the op-amp. It is good at doing oscillator well.

The output frequency is approx 1KHz. We can change C2. More capacitance to less frequency.

Note: I will explain to you the working of these circuits.
In other circuits below.

What is more? Let’s build LM386 projects.

Buy LM386 at Amazon.com

Mini LM386 amplfier

If saving energy is important for you. This circuit is suitable. Because you can use it with a 9V battery at 5mA current. But give the gain of output to approx 50. Or the power of 300mW to 500mW at 8 ohms speaker.

LM386 audio amplifier circuit project


LM386 mini audio amplifier circuit

Imagine you make an AM receiver circuit. You can use this LM386 to amplify to a speaker 0.5W, 2 inches. With a 9V battery can listen sound for long.

Flexible of choosing parts
You can use similar devices. To instead each other.
For example:

  • The loudspeaker—use 4 ohms or 8 ohms. @ 0.25W or 0.5W. And any size as free space.
  • Voltage supply—use 4V to 12V. And low voltage low watts. It is correct.
  • The voltage of capacitors—use High voltage instead of low voltage. For example, C5 is an electrolytic capacitor. You may use 50V instead.
    But… Of course, it is more expensive.

How to builds

If you want to build these circuits. You can finish them on the universal PCB or even the breadboard.

But sometimes you want a PCB board. You can make it with a PCB layout and components layout.

lm386-audio-amplifier-pcb-layout


Figure 2 the PCB and components layout of the LM386 audio amplifier.

Parts lists

0.25W Resistors, tolerance: 5%
R1—10Ω
R2—1.2K
VR1—10K Potentiometer

Capacitors

C1, C2—0.1μF 50V Ceramic
C3,C4—10μF 25V Electrolytic
C5—220μF 16V Electrolytic

Semiconductors and others

IC1—LM386, Low voltage audio amplifier
SP1—8Ω 0.25W speaker
B1—Battery, 9V

Do you like a small Amplifier like this?
Look at more:

Or
Learn all HERE

Buy cheap 386 Kit here

Not only that.

Look:

9V Power Amplifier using LM386

Also, the above circuit. This one of the 9V amplifier circuit diagram. I like it. Because of high gain up to 200.

LM386 Small Power Amplifier use 9V battery operated

LM386 mini amplifier

How it works

To begin with, the signal goes to the input pin 3, non-inverting input. This is a signal amplifier in the non-return phase form.

They have…

  • The C1 absorbs this noise to protect the input.
  • And C2 increases the gain of the amplifier. If you want more gain. You can add more C2 value. But, more value, too distortion (should be lower 100uF).
  • The output comes out of pin 5 of IC1.
  • Then, through C4 coupling the stronger audio signals to better. And DC block and not passed to the speaker.

And while both R1 and C3 in series. They keep the high-frequency response better.

Recommended: Classic active tone control circuit using ICs

Parts lists

0.25W Resistors, tolerance: 5%
R1: 10Ω
R2: 1.2K
VR1: 10K Potentiometer

Capacitors
C1: 0.01μF 50V Ceramic
C2: 10μF 25V Electrolytic
C3: 0.1μF 50V Ceramic
C5: 220μF 16V Electrolytic

Semiconductors and others
IC1: LM386, Low voltage audio amplifier
SP1: 8Ω 0.25W speaker
B1: Battery, 9V

Read Next: TDA2030 stereo amplifier circuit

500 mW Power Amplifier using LM386N

Does it use the 12V battery? Yes, LM386 can work within a car. Because of the long wide voltage supply range from 4V to 12V at 50mA only. Give power out of 500mW at 8 ohms speaker.

Some other features and the frequency response from 40Hz to 100 kHz rate. And the gain of 46 dB. And distortion Less than 1%.

500mW amplifier circuit project using 12V

How it works

First of all, Enter the power supply to the circuit. Then, LED1 lights up to show power on the circuit.

And, capacitors C6 and C7 filtered to smooth.

Then, Enter a signal to the input through C1.

It is the coupling signal to protect DC voltage noise in the circuit.

Next, the sound signal flows through VR1 to turn the volume up or down.

After that, the sound signal goes to pin 3 of IC1.

To increase the sound up. Then, the strong sound comes out of pin 5 through C5. It protects dc voltage and passes the low frequency better to power a loudspeaker.

The C4 and R1 are acting cut noise signal out away.

And, the pin 1 of IC1 has a jumper to access C3 to boost up to gain.
When the input signal is very small.

Hand-picked related articles you may want to read:

What is more?

Parts lists

0.25W Resistors, tolerance: 5%
R1: 10Ω
R2: 1.2K
VR1: 10K Potentiometer

Capacitors
C1: 3.3μF 25V Electrolytic
C2, C6: 0.1μF 50V Ceramic
C3: 10μF 25V Electrolytic
C4: 0.047μF 50V Ceramic
C5: 470μF 16V Electrolytic
C7: 100μF 25V Electrolytic

Semiconductors and others
IC1: LM386N4, Low voltage audio amplifier
LED1: Red LED 5mm.
SP1: 8Ω 1W speaker
B1: Battery, 4V to 12V

Download This Post as a PDF and all PCB layouts

Conclusion

We love LM386, me too. Because it uses a battery. We can test and make them more. It is easy and cheap. What do you think about it?

Sure, this may not enough for you to read more LM386

Keep Reading: LM386 Stereo Amplifier with Bridge model

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14 Comments

  1. nishant

    Hi, I want to know how to give input, and can I use 3.5mm jack to input and use it with mp3 player

  2. shital

    How to give input plz tell fast????

  3. Hi,Shital
    Thanks for your feedback.
    You can use input for any low audio, example: CD audio, MP3, others.

  4. Hi! nice site i would like to ask ..Where i can find the block diagram or schematic diagram for making amp for tweeter and low driver

    High > need amp driver
    Mid > already have sound standard ex1200
    Low > need amp driver

  5. shamim ali

    sir,pls tell me how to give input …???

  6. mike

    hello my name is mike , i am working on the project using the 555 ,but can anyone tell me which pin is whih and wheres does everything connect to because i have no idea where to connect each component to its belonging pin, if anyone can help please comment as soon as possible, thank you

  7. shubhendu

    Hai can we connect two stage ic lm386 amplifier please send me circuit diagram of it to connect these stage with filter circuit and you site give very simple circuits thangs send me answer in my mail

  8. dhiraj

    great …..!!!!!!!!!!!!!!!!!
    useful …… give a info for the audio amplifier using blootooth connector without audio jack

  9. Narayan Dhakal

    i ve a 8 ohm 4 watt speaker what value of capacitance would i ve to use as zobel capacitor? when i searched through the net i found it to be inducatance/resistance^2 So actually how do i khow the henry of the speaker

  10. Priyanka sivaprakasam

    how to generate 85 dB sound?

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