LM49150

LM49150 Mono Class D Audio Subsystem with Earpiece Driver and Stereo Ground Referenced Headphone Amplifiers LM49150 March 4, 2009 Mono Class D Audio Subsystem with Earpiece Driver and Stereo Ground Referenced Headphone Amplifiers General Description 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 8Ω 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. The LM49150 features a fully differential mono input, and two single-ended stereo inputs. The three inputs can be mixed/ multiplexed to either the speaker or headphone amplifiers. Each input channel has an independent, 32-step ...