Dual 105mW Headphone Amplifier with Digital Volume Control and Shutdown Mode

This is a low noise Headphone Amplifier capable of delivering 105mW per channel of continuous average power into a 16Ω load with 0.1% (THD+N) from a 5V power supply. The project is based on the LM4811 chip from the boomer series. The board provides high-quality output power with a minimal number of external components. It features a digital volume control that sets the amplifier’s gain from +12dB to −33dB in 16 discrete steps using a two−wire interface or onboard 3 tactile switches. On-board jumper implements the shutdown feature. The chip also has an internal thermal shutdown protection mechanism.