About LM386 Audio Amplifier Circuit Working and Applications

In this article, we will discuss how to build LM386 audio amplifier circuit. It is a low-cost amplifier and also can power any speaker. For the size and the cost of the circuit, the sound from the IC LM386 audio amplifier can be effectively loud. There are several audio amplifier circuits designed using LM386 IC. The main drawback with these circuits is interference and noise. The noise from this circuit is much less and if designed on a right circuit board, this will create a great Audio Amplifier. The LM386 integrated circuit based audio amplifier circuit is a low power circuit that can supply a maximum power, i.e, 1 Watt (1W) and can be used in an extensive range of applications such as laptop speakers, portable speakers, etc.

What is an Audio Amplifier Circuit?

An audio amplifier is one kind of electronic device, used to increase the amplitude of audio signals that permit it. This type of amplifier increases low-power audio signals to a level which is apt for making loudspeakers. When the input signal of this amplifier is a few 100 micro watts, then its o/p may be tens or even 1000s of watts. Design factors for these amplifiers include gain, distortion, noise and frequency response.

There are several kinds of audio amplifiers and further, we store several of the most common sorts classified by gain, output power, nominal gain bandwidth, maximum supply voltage, type of packaging and also a number of channels. The most common sizes for gain are 20 dB, 26 dB, 30 dB, 36 dB and 48 dB. We also move audio amplifiers with gain as high as 115 dB. The number of frequencies can be between 1 & 10, with the most mutual audio amplifier semiconductor chips consuming 1, 2 or 4 channels.

IC LM386 Audio Amplifier

The IC LM386 integrated is a low-power audio frequency amplifier, which uses batteries for the low-level power supply in electronic circuits. This amplifier is intended as an 8-pin mini DIP package. This offers voltage amplification of 20. By using exterior parts, voltage gain can be higher up to 200. When it works from a 6V power supply, inactive power will be 24 milliwatts, which creates IC LM386 for perfect battery operation.

An LM386 is a very popular and widely used audio amplifier chip that permits a user to amplify sound. LM386 chip comprises of 8 pins where pin 1 and 8 denotes the gain control of the amplifier, and you can adjust the gain by placing resistor or capacitor in between these two terminals

LM386 pin configuration consists of 8-pins where every pin has some role like the following.

Pin Number	Pin Name	Function
1	Gain	Gain Setting Pin
2	Input –	Inverting Input
3	Input +	Non – Inverting Input
4	GND	Ground
5	Vout	Output
6	Vs	Power Supply Voltage
7	Bypass	Bypass decoupling path
8	Gain	Gain Setting Pin

IC LM386 Audio Amplifier Circuit

The required components of this audio amplifier design mainly include LM386 Audio Amplifier IC, 1000 µF Capacitor, 100 µF Capacitor, 10 µF Capacitor, 0.05 µF Capacitor, 10 KΩ Potentiometer, 10 Ω Resistor, 4 Ω Speaker, 12V Power Supply, Connecting Wires and Breadboard.

Functionally, the IC LM386 Audio Amplifier can be separated into three functional blocks, namely Gain Control, Power & Output, Bypass. The circuit design of LM386 is very simple. First connect the power supply pins namely pi4 and pin6 to voltage supply and ground respectively.

Next, we must connect the input, which can be given from any audio source like a microphone or a mobile phone. We have given the audio as an input from a mobile phone using the 3.5mm connector. A 3.5mm connector will have three connections such as right audio, left audio and the ground. Since this IC is a Simple Audio Amplifier, we need to attach either the Right Audio or Left audio from the source along with GND. Otherwise, both the channels can be joint to produce a mono channel using suitable resistors.

If we want to control the input level, a KΩ Potentiometer must be connected to the input. Additionally, a capacitor can be connected in series with the i/p to filter out the DC components. The gain of the LM386 is set to 20 internally. We connected a 10 µF Capacitor among the gain control pins like pins 1 and pin 8. Hence, the gain is now fixed to a factor of 200.

Although the audio amplifier data sheet tells the bypass capacitor at Pin-7 is a choice, we create that connecting a 100 µF capacitor was really useful as it aids in decreasing the noise. It can be left open for the usual process.

For the o/p connection, first, connect a 10 Ω Resistor and a 0.05 µF Capacitor in series between the output pin-5 and GND. This makes a Zobel n/w, a filter comprising of resistor & capacitor in series and is used to fix the i/p impedance of the driver.

Next is the speaker connection. IC LM386 audio amplifier can drive any speaker in the impedance range of 4 Ω-32 Ω., and the circuit uses a 4 Ω Speaker. Connecting the 4 Ω Speaker through a 1000 µF capacitor was truly helpful as it filtered out the excessive DC signals.

Applications of Audio Amplifier

• The applications of IC LM386 audio amplifier include the following
• This is one of the most important audio amplifiers and it is featured commonly laptop and portable speakers.
• This Circuit is used to record the voice from microphone, small speakers that are operated with a battery in FM Radio Devices, etc.
• These amplifiers can also be used in Line Drivers, Servo Drivers, TV Sound Systems, Ultrasonic Drivers, etc.

Thus, this is all about LM386 audio amplifier IC which circuit working with applications. Furthermore, any queries regarding this article or to implement any electrical and electronic projects, you can approach us by commenting in the comment section below. Here is a question for you, What is the function of an audio amplifier?