LM386 Audio Amplifier IC (DIP-8)

The LM386 is a voltage audio power amplifier integrated circuit. It comes in a DIP-8 through-hole package. It is made for battery-powered consumer and hobbyist audio systems. It is designed to use few extra parts as possible. Its internal voltage gain is set to 20. This keeps the number of parts to a minimum.. It can be increased to 200. This is done by putting a capacitor and resistor network between pins 1 and 8.

It uses little power when not active. It can use little as 24 mW on a 6V supply. The LM386 is a choice for portable AM/FM radios. It is also used in intercoms. It works well in guitar practice amps. It is used in walkie-talkies and microcontroller sound generators.

Key Features

• Minimal External Part Count: It has a built-in biasing network. This allows amplification with just a few external capacitors.
• Flexible Gain Configuration: It can switch between a low-gain setup of 20x.. It can use a high-sensitivity boost of 200x. This is done with a 10 µF capacitor across pins 1 and 8.
• Low Battery Drain: The power it uses when not active is under 8 mA. This makes it good for 9V or 3.7V Li-ion boosted designs.
• Breadboard-Friendly DIP-8 Form: It is easy to use for prototyping. It is also good, for repairs or swapping on socketed custom PCBs. No surface-mount soldering tools are needed.

Pinout Configuration (DIP-8)

• Pin 1 (Gain): Gain setting terminal (used with Pin 8).

• Pin 2 (-IN): Inverting audio input.

• Pin 3 (+IN): Non-inverting audio input (typically fed via volume potentiometer).

• Pin 4 (GND): Power and signal ground.

• Pin 5 (Vout): Amplified audio output (couples to speaker via electrolytic capacitor).

• Pin 6 (Vs / VCC): Positive DC power supply terminal.

• Pin 7 (Bypass): Decoupling capacitor connection to reduce supply hum/noise.

• Pin 8 (Gain): Gain setting terminal (used with Pin 1).