IC LM386 Audio Amplifier Pin Configuration and Its Working

The IC LM386 is a low-power audio amplifier, and it utilizes low power supply like batteries in electrical and electronic circuits. This IC is available in the package of mini 8-pin DIP. The voltage gain of this amplifier can be adjusted to 20, and the voltage gain will be enhanced to 200 by employing external components like resistors as well as capacitors among the pins 1 & 8. When this amplifier uses a 6V power supply for the operation then the static power drain will be 24 milliwatts to make the amplifier for an ultimate operation of the battery. This amplifier consists of 8-pins where pin-1 and pin-8 are gain control pins of the amplifier, and this IC is most widely used IC that allows a customer to increase volume.

IC LM386 Pin Configuration

The IC LM386 audio amplifier consists of 8-pins where each pin of this IC is discussed below.

IC LM386 Pin Configuration
IC LM386 Pin Configuration
  • Pin1 (Ga+-gain Pin): Pin-1 is gain pin, used adjust the amplifier gain by connecting this IC to an external component capacitor.
  • Pin2 (+IN-Non-inverting): Pin-2 is the non-inverting pin, is used to provide the audio signal.
  • Pin3 (+IN): Pin-3 is the inverting terminal and it is normally connected to ground.
  • Pin4 (GND): Pin-4 is a ground pin connected to the ground terminal of the system
  • Pin5 (Vout): Pin-5 is the output pin, used to provide amplified output audio, and allied to the speaker.
  • Pin-6 (VCC or VSS): Pin-6 is connected to the power
  • Pin-7 (Bypass): Pin-7 bypass pin is used to connect a decoupling capacitor.
  • Pin-8 (Gain): Pin-8 is the gain setting pin

LM386 Audio Amplifier Circuit Diagram and Working

The Audio amplifier can be built with LM386 IC, capacitors like 100 µF, 1000 µF, 0.05 µF, 10 µF, Potentiometer – 10 KΩ, resistor-10 KΩ, power supply-12V, speaker-4Ω, breadboard, and connecting wires. Basically, this Audio Amplifier includes 3-functional blocks such as Power as well as Output, Bypass, gain control. Designing of this circuit design is so simple. At first, connect the two power supply pins namely pin4 & pin6 to GND as well as voltage correspondingly.

IC LM386 Audio Amplifier Circuit
IC LM386 Audio Amplifier Circuit

After that, connect the input from any kind of audio sources such as a mobile phone or a microphone. Here this circuit uses a mobile phone as the audio source with the help of the 3.5mm connector. This connector will be having three connections like the ground right and left audio. This LM386 IC is a simple amplifier and connects the right or left audio to this amplifier using an audio source with the ground terminal. The input level in this circuit can be controlled by connecting a potentiometer to the input. In addition, a capacitor will be connected to the input in series to remove the DC components. This IC gain will be adjusted to 20, and connect a capacitor (10 µF) between the two pins 1 & 8 of this IC then the gain will be enhanced to 200

Even though the datasheet of audio amplifier advises the bypass-capacitor at the 7th pin is an option, we form that connecting a capacitor (100 µF) was truly helpful because it assists in the noise reduction. For the connection of output, a capacitor (0.05 µF) and a resistor (10 Ω) will be connected in series among the GND as well as a 5th pin of the IC. This forms a Zobel network, a filter including a capacitor and resistor will be utilized for adjusting the input impedance.

The speaker connection can be done with the help of impedance ranges from 4 Ω to 32 Ω, because the IC can drive any type of speaker in this range. The audio amplifier circuit uses a speaker (4 Ω). This speaker can be connected using a capacitor (1000 µF) was really useful because it removes the unnecessary DC signals.

Electrical Characteristics of LM386 IC

  • The voltage gain of this amplifier can be set from 20 to 200 with a range of voltage supply 4volts to 12volts or 5volts to 18 volts based on the model. There are three amplifier models are available in the market namely LM386N-1, LM386N-3, & LM386N-4
  • For LM386N-1: Minimum voltage is 4V, Maximum voltage is 12V, Minimum o/p power is 250 mW and typical o/p power is 325mW.
  • For LM386N-3: Minimum voltage is 4V, Maximum voltage is 12V, Minimum o/p power is 500 mW and typical o/p power is 700mW.
  • For LM386N-4: Minimum voltage is 5V, Maximum voltage is 18V, Minimum o/p power is 500 mW and typical o/p power is 1000mW.
  • The inputs of the amplifier are referenced by ground whereas the output routinely biases toward one half of the voltage supply. The low static current of the amplifier is 4mA and the harmonic distortion will be up to 0.2%

Features of IC LM386

The main features of LM386 chip include the following.

  • IC LM386 is obtainable in the package of 8-pin MSOP
  • Exterior components are minimum
  • Operation of Battery
  • Low static power drain- 4mA
  • The range of supply voltage is wide which is ranges from 4Volts to 12Volts or 5Volts to 18 Volts.
  • Input is referenced by ground
  • Distortion is less 0.2%
  • Self-centering o/p static voltage
  • The voltage gain range will be from 20 to 200

LM386 Applications

The IC LM386 is the most important integrated circuit used in the audio section, and it is commonly used in the following applications.

  • Wien bridge oscillator
  • Power converters
  • Ultrasonic drivers
  • Small servo drivers
  • Intercoms
  • Line drivers
  • TV sound systems
  • Portable tape player amplifiers
  • AM to FM radio amplifiers
  • Audio boosters
  • Used in speakers of laptop & portable
  • Used for voice record from microphone, battery operated speakers.

Thus, this is all about IC LM386, and this article gives an overview of how to design an IC LM386 audio amplifier circuit, and the making of this circuit is very simple, small size as well as less cost. So the sound from this amplifier will be very loud. There are various kinds of amplifiers can be built with the help of IC LM386, but the main drawback of this circuit is interference as well as noise. The proposed system can be designed with less noise. This circuit will deliver a 1 Watt of power & can be applied in a wide range of audio devices like speakers in laptops, handy speakers, etc.

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