Headphone Amp Doubles Playback Time

Extending battery life in portable audio products, the LM48824 stereo headphone amplifier exploits a Class G architecture that significantly increases audio playback time with its adaptive power supply approach that enables very low supply rails. This is said to double power-efficiency when compared to typical Class AB headphone amplifiers. The device typically draws 0.9 mA of quiescent current and is available in a 16-bump, 1.7 mm x 1.7 mm, 0.4 mm-pitch micro SMD package. It includes a 32-step I2C-compatible volume control with mute and delivers 37 mW per channel into a 16-Ohm load with less than 1% THD+N at 3.6V. Other specs include a power supply rejection ratio of 105 dB at 217 Hz, which enables the device to operate in noisy environments without additional power-supply conditioning. Available now, price is $1.06 each/1,000. For more information, call NATIONAL SEMICONDUCTOR CORP., Santa Clara, CA. (800) 272-9959.