LM4981

www.DataSheet4U.com LM4981 Ground-Referenced, 80mW Stereo Headphone Amplifier with Digital Volume Control November 2005 LM4981 Ground-Referenced, 80mW Stereo Headphone Amplifier with Digital Volume Control General Description The LM4981 is a stereo, ground-referenced, output capacitor-less headphone amplifier capable of delivering 83mW of continuous average power into a 16Ω load with less than 1% THD+N while operating from a single 3V supply. The LM4981 features a new circuit technology that utilizes a charge pump to generate a negative reference voltage. This allows the outputs to be biased about ground, thereby eliminating output-coupling capacitors typically used with normal single-ended loads. The LM4981 provides high quality audio reproduction with minimal external components. A ground referenced output eliminates the output coupling capacitors typically required to drive single-ended loads such as headphones. The ground reference architecture reduces components count, cost and board space consumption, making the LM4981 ideal for handheld MP3 players, mobile phones and other portable equipment where board space is at a premium. Eliminating the output capacitors also improves low frequency response. The LM4981 operates from a single 2.0V – 4.2V supply, and features a 2-wire, up/down volume control that sets the gain of the amplifier between -33dB to +12dB in 16 discrete steps. Selectable (active high/low) low power shutdown mode provides flexible shutdown control. Supe...