Class G Headphone Amp Extends Playback Time

Emerging as the industry’s first stereo analog subsystem with integrated Class G headphone amplifier and automatic level control, the PowerWise LM49251’s Class G headphone amp dynamically reduces the supply voltage to lower power consumption and extend playback time. The analog subsystem combines a 1.4W Class D speaker amplifier, 20 mW Class G headphone amplifier, and ALC in a 2.55 mm x 3.02 mm package. Consumption is less than 7 mA of quiescent current at 3.3V for the loudspeaker and headphone. Additionally, the ALC feature offers a programmable output power limiter for speaker protection and clip level select. Available now, the LM49251 stereo analog subsystem is priced at $1.60 each/1,000. NATIONAL SEMICONDUCTOR CORP., Santa Clara, CA. (800) 272-9959.