LM1876 high-fidelity power amplifier circuit

LM1876 is a high-fidelity two-channel audio power amplifier integrated circuit with an output power of 2 × 20W and a 15-pin fully insulated package. It was launched by National Semiconductor (NS) at the end of 1996 and has NS's patented SPIKE instantaneous temperature drop protection circuit, complete overvoltage, undervoltage, and overload protection, transistor safe operating area protection, and fade-in and fade-out noise reduction modes.

LM1876 main parameters:

Power supply voltage: ±20 ―±35V

Continuous undistorted power: 2 × 20W

Total harmonic distortion (THD+N): 0.08%

Rate: 18v/us

Signal-to-noise ratio: >98dB.

Channel separation: 80dB

Output current: 3.5A

Peak power: 62.5W

Power amplifier circuit designed with LM1876:

This power amplifier circuit is designed as a DC servo constant current power amplifier, which is more pleasant to listen to than the voltage feedback connection. The output adopts a four-wire system, and no common terminal is allowed. The input line should be shielded to further improve the signal-to-noise ratio. The internal resistance of the power supply should be small, and sufficient power reserve must be reserved to prevent clipping distortion and overload distortion during large dynamics.