Filterless 2.5w Stereo Class D Audio Power Amplifier - National Semiconductor

The LM4674 is a single supply, high efficiency, 2.5W/ channel, filterless switching Audio Amplifier A low noise PWM architecture eliminates the output Filter reducing ex- ternal component count, board area consumption, system cost, and simplifying design. The LM4674 is designed to meet the demands of mobile phones and other portable Communication devices. Operat- ing from a single 5V supply, the device is capable of deliv- ering 2.5W/channel of continuous output power to a 4 load with less than 10% THD+N. Flexible power supply require- ments allow operation from 2.4V to 5.5V. The LM4674 features high efficiency compared to conven- tional Class AB Amplifiers When driving and 8 speaker from a 3.6V supply, the device features 85% efficiency at PO = 500mW. Four gain options are pin selectable through the GAIN0 and GAIN1 pins. Output short Circuit Protection prevents the device from be- ing damaged during fault conditions. Superior click and pop suppression eliminates audible transients on power-up/down and during shutdown. Independent left/right shutdown con- trols maximizes power savings in mixed mono/stereo appli- cations. By National Semiconductor Corporation