This is 68W power audio amplifier circuit which built based on single IC LM3886 from National Semiconductor. A LM3886 used for single channel operation. Dual polarity / split / symmetrical power supply used to operate this amplifier circuit.
The LM3886 is a high-performance audio power amplifier capable of delivering 68W of continuous average power to a 4 ohm load and 38W into 8 ohm with 0.1% THD+N from 20Hz-20kHz.
LM3886 Amplifier Specifications:
Maximum Output Power : 68W RMS - 108W Peak THD : %0.03 at 60W SNR : 110dB at 60 W - 92.5dB at 1W PSRR : 120dB Protection Circuitries : DC /AC Short circuit protection and thermal protection Output Class : Conjugate AB-A
The performance of the LM3886, utilizing its Self Peak Instantaneous Temperature (°Ke) (SPiKe™) protection circuitry, puts it in a class above discrete and hybrid amplifiers by providing an inherently, dynamically protected Safe Operating Area (SOA). SPiKe protection means that these parts are completely safeguarded at the output against overvoltage, undervoltage, overloads, including shorts to the supplies, thermal runaway, and instantaneous temperature peaks.
The LM3886 maintains an excellent signal-to-noise ratio of greater than 92dB with a typical low noise floor of 2.0uV. It exhibits extremely low THD+N values of 0.03% at the rated output into the rated load over the audio spectrum, and provides excellent linearity with an IMD (SMPTE) typical rating of 0.004%.
Download the LM3886 datasheet document: