A very simple high efficiency 80W audio power amplifier project can be designed using the LM3875 power audio IC . LM3875 is a high-performance audio power amplifier capable of delivering 56W of continuous average power to an 8Ω load with 0.1% THD+N from 20Hz to 20kHz .
By connecting two LM39875 audio IC in bridge mode this audio power amplifier will deliver 80 watt of output power into an 8 Ohm load. The LM3875 IC devices should be suitably heatsinked.
As you can see in the circuit diagram , this power audio amplifier require few external electronic parts .
The LM3875 maintains an excellent signal-to-noise ratio of greater than 95dB(min) with a typical low noise floor of 2.0μV.
This 80W audio power amplifier module accepts a wide range input voltage from 20 up to 84 volts, but typically is recommended ( for this circuit ) a dual +/-25 volts DC power supply .
Some features of this 80W audio power amplifier project based on the LM1875 IC are :
output protection from a short to ground or to the supplies via internal current limiting circuitry ,output over-voltage protection against transients from inductive loads ,supply under-voltage protection .
