LM386 Low Voltage Audio Power Amplifier IC SOP-8

LM386 Low Voltage Audio Power Amplifier IC SOP-8 is a highly versatile integrated circuit designed specifically for low-voltage consumer applications where power efficiency and minimal external components are essential. This power amplifier allows for a default internal gain of 20, however, you can easily increase this gain up to 200 by adding an external resistor and capacitor between specific pins. The SOP-8 surface-mount package ensures that this IC fits perfectly into modern, compact PCB designs. Consequently, it has become a staple in portable electronics due to its low quiescent current drain and wide supply voltage range. Furthermore, the LM386 provides excellent audio performance for its size, making it a reliable choice for hobbyists and professional engineers alike. Therefore, you can confidently integrate this IC into any project requiring battery-operated audio amplification.

Key Features:

• Battery Operation: The low quiescent current draw of approximately 4 mA makes it ideal for portable, battery-powered devices.
• Adjustable Gain: While the internal gain stays at 20 by default, adding external components allows you to scale the gain from 20 to 200.
• Wide Supply Range: This IC operates efficiently on voltages ranging from 4 V to 12 V, providing flexibility for different power sources.
• Self-Centering Output: The output quiescent voltage automatically centers to half the supply voltage, simplifying circuit design.
• Minimal Distortion: It maintains low ground-referenced input impedance and low distortion levels during standard operation.

Technical Specifications:

• Supply Voltage (V_S): 4 V to 12 V (Standard variant)
• Quiescent Current (I_Q): 4 mA (Typical), 8 mA (Maximum)
• Voltage Gain (A_V): 20 to 200 (Adjustable)
• Output Power (P_OUT): ≈ 325 mW at V_S = 6 V, R_L = 8 Ω
• Bandwidth (BW): 300 kHz (at Gain = 20)
• Total Harmonic Distortion (THD): 0.2% (Typical)
• Input Resistance (R_IN): 50 kΩ

Mechanical Specifications:

• Package Type: SOP-8 (Small Outline Package)
• Mounting Type: Surface Mount Technology (SMT)
• Lead Material: Alloy 42 or Copper
• Moisture Sensitivity: MSL Level 1

Dimensions:

• Body Length: ≈ 4.90 mm
• Body Width (including leads): ≈ 6.00 mm
• Body Thickness: ≈ 1.55 mm
• Pin Pitch: 1.27 mm

Pinout and Wiring:

• Pin 1 & 8 (Gain): Connect a 10 μF capacitor between these pins to increase gain to 200.
• Pin 2 (Input −): Inverting input; typically connected to ground in single-ended configurations.
• Pin 3 (Input +): Non-inverting input; apply the audio signal to this pin.
• Pin 4 (GND): Connect to the system ground.
• Pin 5 (Vout): The amplified audio output; connect to a speaker via a coupling capacitor.
• Pin 6 (Vs): Connect to the positive DC supply voltage.
• Pin 7 (Bypass): Connect a decoupling capacitor here to improve power supply rejection.

Datasheet Reference:

• Download Texas Instruments LM386 Datasheet

Commonly Used in:

• AM-FM Radio Amplifiers: Providing the final output stage for small portable receivers.
• Portable Music Players: Driving headphones or small 8-ohm speakers in mobile gadgets.
• Intercom Systems: Facilitating clear voice communication in battery-operated units.

Applications:

• TV Sound Systems: Serving as a low-power audio driver in older or compact television sets.
• Ultrasonic Drivers: Utilizing the high bandwidth for specialized frequency applications.
• Signal Generators: Amplifying low-power waveforms for testing and hobbyist experiments.
• Small Power Converters: Repurposing the output stage for simple oscillation or conversion tasks.

Equivalent Models:

• LM380: A higher power version, however, it features a fixed gain and different pinout.
• TDA2822: A dual-channel audio amplifier often used as a stereo alternative to the LM386.
• KA386: A direct functional equivalent manufactured by Fairchild/Samsung with identical specifications.

Package Includes:

• 1 x LM386 Low Voltage Audio Power Amplifier IC SOP-8