MAX9778

19-0509; Rev 0; 4/06 www.DataSheet4U.com Stereo 3W Audio Power Amplifiers with Headphone Drive and Input Mux General Description The MAX9777/MAX9778 combine a stereo 3W bridgetied load (BTL) audio power amplifier, stereo singleended (SE) headphone amplifier, headphone sensing, and a 2:1 input multiplexer all in a tiny 28-pin thin QFN package. These devices operate from a single 4.5V to 5.5V supply and feature an industry-leading 100dB PSRR, allowing these devices to operate from noisy supplies without the addition of a linear regulator. An ultra-low 0.002% THD+N ensures clean, low-distortion amplification of the audio signal. Patented click-andpop suppression minimizes audible transients on power and shutdown cycles. Power-saving features include low 4mV VOS (minimizes DC current drain through the speakers), low 13mA supply current, and a 10µA shutdown mode. A MUTE function allows the outputs to be quickly enabled or disabled. A headphone sense input detects the presence of a headphone jack and automatically configures the amplifiers for either speaker or headphone mode. In speaker mode, the amplifiers can deliver up to 3W of continuous average power into a 3Ω load. In headphone mode, the amplifier can deliver up to 200mW of continuous average power into a 16Ω load. The gain of the amplifiers is externally set, allowing maximum flexibility in optimizing output levels for a given load. The amplifiers also feature a 2:1 input multiplexer, allowing multiple audio sources to be...