The LM49150 is a fully integrated audio subsystem designed for portable handheld applications such as cellular phones. Part of National's Power Wise product family, the LM49150 consumes very low power in the various modes of operation and still providing great audio performance. The LM49150 combines a 1.25W mono E2S (Enhanced Emission Suppression) class D amplifier, 135mW Class AB earpiece amplifier, 42mW/channel stereo ground reference headphone amplifiers, volume control, and mixing circuitry into a single device. The filterless class D amplifier delivers 1.25W into an 8 load with <1% THD+N with a 5V supply. The E2S class D amplifier features a patented, ultra low EMI PWM architecture that significantly reduces RF emissions while preserving audio quality. The 42mW/channel headphone drivers feature National's ground referenced architecture that creates a ground-referenced output from a single supply, eliminating the need for bulky and expensive DC-blocking capacitors, saving space and minimizing cost.