HiFi headphone amplifier circuit

admin January 7, 2011 4 Comments

Description.
LM4880 is HiFi dual audio amplifier IC from National Semiconductors. This IC is specifically designed to produce high quality audio output with a minimum number of external components.LM4880 is capable of delivering 250mW per channel into an 8 ohm load. The IC has 0.1% THD and has a supply voltage range of 2.7 to 5V DC.

In the circuit shown below, resistors R1 and R2 are feedback resistors.C4 and C5 are input DC decoupling capacitors. Capacitor C3 provides power supply filtering and thereby reduces noise. The amplifier automatically shut downs when a logic high is given to the shutdown pin (pin 5). Capacitor C6 does the job of half supply filtering.

Circuit diagram.

Notes.

  • Assemble the circuit on a good quality PCB.
  • The circuit can be powered from anything between 2.7 to 5V DC.
  • A logic high at pin % will drive the amplifier to shut down mode.
  • To a 32 ohm headphone the amplifier will deliver 85mW at 0.1% THD.

Comments
  • September 14, 2013

    […] you want to listen to music from your MP3 player, you will have to adjust the headphone to your ears and then switch on the player that is kept in your pocket. But, with this technology, […]

  • Seetharaman
    April 2, 2011

    Hi Edgar Thanks it is a mistake C3 & C4 should be resistances of value 20K ohms each.

  • edgar
    April 1, 2011

    in the above diagram what are the value of R3 and R4; are they in ohms or micro Farads? thanks, i appreciate your site. . .

  • CALOY
    March 17, 2011

    what value of resistor should i use to match the output impedance of this to the input impedance of tda1554Q???

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