High Performance Stereo Audio Amplifier using LM3886

Rajkumar Sharma      http://www.rajkumarsharma.com  
4649
Project tested

The LM3886 is a high-performance audio power amplifier capable of delivering 68W of continuous average power to a 4Ω load and 38W into 8Ω with 0.1% THD+N from 20Hz–20kHz.

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, under voltage, 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 2.0µV. 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%.

Note : Amplifier Requires a Large Size Heat sink

Features

  • 68W Cont. Avg. Output Power into 4Ω at VCC = ±28V
  • 38W Cont. Avg. Output Power into 8Ω at VCC = ±28V
  • 50W Cont. Avg. Output Power into 8Ω at VCC = ±35V
  • 135W Instantaneous Peak Output Power Capability
  • Signal-to-Noise Ratio ≥ 92dB
  • An Input Mute Function ( J1 & J2 Jumper)
  • 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, not Allowing Internal Biasing to Occur when |VEE| + |VCC| ≤ 12V, thus Eliminating Turn-On and Turn-Off Transients
  • Input Slandered Audio Line signal

Schematic

Parts List

PCB

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