The circuit diagram shown here is of a 2 x 60 Watt stereo amplifier based on the LM4780 from National Semiconductors. LM4780 is a superb audio amplifier IC capable of delivering 60W Rms power output / channel into 8 ohm speakers. The LM4780 has very low total harmonic distortion (less than 0.5% at full output) and has a power supply rejection ration (PSRR) of 85 dB. The IC requires very few external components and has a built in mute facility. The LM4780 is completely protected using their trademark SPiKe technology and has a signal to noise ratio greater than 97dB. The circuit given here is well suitable for applications like components stereos, self powered speakers, home theatre systems, compact stereos etc.
LM4780 pin configuration
- The circuit must be assembled on a good quality PCB.
- The amplifier can be powered using a 35V DC dual supply.
- K1 and K2 must be 8 ohm, 60W speakers.
- An adequately sized heat sink must be fitted to the IC.