lm386 audio amplifier circuit diagram with PCB

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• Battery operation
• Minimum external parts
• Wide supply voltage range: 4V-12V or 5V-18V
• Low quiescent current drain: 4mA
• Voltage gains from 20 to 200
• Ground referenced input
• Self-centering output quiescent voltage
• Low distortion: 0.2% (A_V = 20, V_S = 6V, R_L = 8[Ohm], P_O = 125mW, f = 1kHz)
• Available in 8 pin MSOP package

Applications

• AM-FM radio amplifiers
• Portable tape player amplifiers
• Intercoms
• TV sound systems
• Line drivers
• Ultrasonic drivers
• Small servo drivers
• Power converters

Equivalent Schematic lm386 pinout datasheet and Connection Diagrams  LM386M-1, LM386MM-1, LM386N-1, LM386N-3 or LM386N-4

Application Hints

GAIN CONTROL
To make the LM386 a more versatile amplifier, two pins (1and 8) are provided for gain control. With pins 1 and 8 open the 1.35 kΩ resistor sets the gain at 20 (26 dB). If a capacitor is put from pin 1 to 8, bypassing the 1.35 kΩ resistor, the gain will go up to 200 (46 dB). If a resistor is placed in series with the capacitor, the gain can be set to any value from 20to 200.

Gain control can also be done by capacitive coupling a resistor (or FET) from pin 1 to ground. Additional  external  components  can  be  placed  in  parallel with the internal feedback resistors to tailor the gain and frequency  response  for  individual  program.

For  example, we  can  compensate  poor  speaker  bass  response  by  frequency shaping the feedback path. This is done with a series RC from pin 1 to 5 (paralleling the internal 15 kΩ resistor). For 6 dB effective bass boost: R. 15 kΩ, the lowest value for good stable operation is R = 10 kΩ if pin 8 is open. If pins1 and 8 are bypassed, then R as low as 2 kΩ can be used. This restriction is because the amplifier is only compensated for closed-loop gains greater than 9.

Schematic of power audio amplifier for applications as Amplifiers of radio FM, Amplifiers of MP3 portable players, Intercoms, Systems of sound of TV and other applications.

lm386 audio amplifier circuit diagram schematic

The power supply for this circuit should be 3 to 12 volts.

Suggestion of printed circuit board PCB

Part List for the LM386 Amp

Part	Value
Resistors 1/4W 5%
R1	10 — Brown, Black, Gold, Gold
R2	1.2k — Brown, Red, Red, Gold
R3	4.7K — Yellow, Violet, Red, Gold
R4	1.5K — Brown, Green, Red, Gold (Optional)
R5, R6	10K — Brown, Black, Orange, Gold
Capacitors
C1, C6	10µF/16V — Electrolytic capacitor
C2	220µF/16V — Electrolytic capacitor
C3	100n — Ceramic or polyester capacitor
C4	1000µF/16V — Electrolytic capacitor
C5	100n — Ceramic Capacitor
Semiconductor
IC1	LM386n – DIP8 audio amplifier IC
Connectors
J2	P2 connector – audio input.
J1	Jack Connector – DC Power
CN1	Audio input connector (optional)
CN2	Power connector (Optional)
JP1	Gain adjustment jumper (optional)
LED1	Red LED 5 mm (Optional)
CN3	Terminal block 2 pin 5.08 mm
Miscellaneous
P1	Simple Potentiometer 4.7K to 10K
4.5 to 12V /1A power supply
PCB, solder, wires, Box, knob, etc.

Last update: 04/08/2021 16:34

Download the circuit PCB in PDF, PNG and Gerber
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If you liked this one, then check out the new version, stereo and with power supply design.

Download LM386 datasheet PDF