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  • lm3886 packageThe LM3886 is a high performance 150W Audio Power Amplifier with Mute. The performance of the audio power LM3886, say NS, utilising its Self Peak Instantaneous Temperature (°Ke) (SPIKe) protection circuitry, puts in a class above discrete and hybrid amplifiers by providing an inherently, dynamically protected Safe Operating Area (SOA).

    The LM3886T comes in an 11 (staggered-) lead non-isolated TO220 package. For test purposes, the prototype of the amplifier was powered by a stabilised ±35-V supply. A maximum undistorted output power of about 63 watts into 8 ohms was obtained at a drive level of 1 Vrms. Dropping the load impedance to 4 ohms pushed the output power to no less then 108 watts. In practice, these power levels can be taken to mean ‘music power’, but do remember that the amplifier will not normally be powered from a regulated supply!

    LM3886 amp circuit diagram

    • The circuit needs a well regulated and filtered 28V dual power supply.
    • If you need some more punch extend the supply voltage up to 35V.
    • Switch S1 is used for mute function, open it to mute the amplifier.

    LM3886 circuit version 1

    lm3886 amp

    LM3886 schematic version 2

    Build the amplifier following the schematic and PCB. As always, when testing it, test with a cheap speaker that damage to will not cost much to replace.
    If your source is consistantly connected (ex. a pre-amp always connected to the amplifier), you can skip C2 by soldering a jumper in place of it on the PCB. If possible I would highly reccomend doing this to decrease signal path and increase audio quality. However, if your source may ever get disconnected (such as a CD player), it is reccomended that you include C2. If you do not, disconnecting the source will send a large DC current into the speaker and will very likely damage it. (from)
    lm3886 amp

    LM3886 PCB + circuit version 3

    lm3886 circuit
    lm3886 pcb
    LM3886 BTL stereo amp + PCB (top & bottom) version 4 from

    The LM3886 bridge circuit is in a non-inverted configuration, so the input impedance is determined by the input resistor R1, i.e. 47k. The 680 ohm and 470pF resistor capacitor filter network is used to filter out the high frequency noise at the RCA input. The 220pF C4 and C8 capacitors are used to shot out the high frequency noise at the LM3886 input pins.

    lm3886 schematic

    The PCB is designed in a way that the power ground is separated from the signal ground, as you can see from the below layout. The signal ground is located in the middle and surrounded by the power ground. There is a thin trace near C5 connecting them. The PCB layout is done by using PADS PowerPCB 5.0. I think it is a powerful layout software.

    lm3886 pcb top

    lm3886 pcb bottom

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    11 Responses to "LM3886 Amplifier Circuit"

    1. Please, an electrical diagram for troubleshooting a sharp stereo tuner has 10

    2. santhosh says: on August 4, 2009 at 2:09 pm

      I was inspired on seeing ur schematic, i want to know that what sort of woffer should i use for this IC

    3. Arul Raja says: on August 28, 2009 at 9:56 am

      I will try. after submit the report.

    4. How do you supply the – voltage? I was going to use a wall wart to supply the + but I do not how to supply negative voltage?

    5. I was build lm3886tf (basic as the manufacturer schema). At the output (to speaker), it shows dc voltage as high as psu voltage, +/_32V. I had already double… triple… checked the schematic & circuitry and found nothing wrong connected, include the grounding path. Why?

    6. Where’s the power supply schematic????

    7. Or possibly a link to a known working one for this amp :)

    8. I built a pair of similar amps but the gain is terrible, when playing MP3s from my player. My power supply is a regulated +-30V DC pushing 5A from two LM338s. Do I need to run a pre-amp into this to make it louder?

    9. Asi dori un soft cu ajutorul caruia sa pot comanda 3 releie care sunt conectate la mufa seriala de iesire a calculatorului . releele sa poata fi comandate sa lucreze la timpi diferiti in cele 24 de ore a unei zile. Cine ma poate ajuta ?
      Multumesc .

    10. esta interesante y antemano se que son funcionales

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