How to design an Audio amplifier circuit using IC LM386

Amplifiers are used to raise the strength of an input signal and should output a signal that has been amplified. Audio amplifiers are commonly used in stereo and home theatre systems, as well as in mini speakers, etc. There are various methods for constructing an Audio amplifier circuit, but none are as effective as employing a specialized Audio amplifier IC. This circuit uses the simplest and most cost-effective audio amplifier chip, LM386.


IC LM386:


Due to its low-power consumption, LM386 is utilized in most audio circuits. This integrated circuit can produce an output gain of around 200 when combined with external components. However, when used without extra components, it is capable of 20-fold amplification.

The gain level can be altered by connecting a capacitor or RC pair between pins 1 and 8. The audio input was provided through the non-inverting input pin, whereas the inverting input was often grounded.


  • Supply Voltage: 4-15V
  • Quiescent Power: 24mW @ 6V
  • Analog input voltage 0.4V (maximum)
  • Voltage Gain: 20 to 200 (26dB to 46dB)
  • PSRR: 50dB
  • Speaker impedance 4Ω
  • Available in 8-Pin PDIP, SOIC and VSSOP packages

Working Of Audio Amplifier Circuit:

The LM386 is accompanied by resistor R1 and capacitor C2 when Vcc powers it. This is done to prevent circuit oscillations. The Resistor R2 and Capacitor C3 play a significant part in the above circuit since they affect the output gain. Adding a single 10uF capacitor will help us achieve maximum gain. In conjunction with resistor R2, you can get a gain of approximately 50dB. Connect the positive terminal of C3 to pin 1 and the negative terminal to pin 8 of the IC LM386.

C1 was used to connect the output to the speaker, while POT can be used to adjust the output signal’s gain. Set LM386 gain to high when input signal voltage is extremely low. You can send any audio signal to this circuit and it will serve its intended purpose well.


  • AM and FM Radio amplifiers
  • Portable music players
  • Low Power Audio amplifiers
  • Wien bridge oscillator
  • Power Amplifiers
  • Audio boosters


Hope this blog helps you to understand how to design an Audio amplifier circuit using IC LM386. We, MATHA ELECTRONICS will come back with more informative blogs.

Back to list

Leave a Reply

Your email address will not be published.