The MAX9850 is a low-power, high-performance stereo audio DAC with an integrated DirectDriveTM headphone amplifier. The MAX9850 is designed to meet the board space and performance requirements of portable devices such as cell phones and MP3 and portable DVD players. The MAX9850 uses Maxim's patented DirectDrive headphone technology that produces a ground-biased analog audio output from a single supply, which allows for driving the headphones directly from the amplifier outputs without large DC-blocking capacitors. This feature saves board space, provides higher click/pop suppression, and improves low-frequency (bass) response. The architecture does not require the headphone jack to be biased to a DC voltage and thus allows for a conventional, grounded chassis design. The MAX9850's flexible clocking circuitry utilizes any available system clock up to 40MHz, eliminating the need for an external PLL and multiple crystal oscillators. The DAC supports a wide range of sample rates from 8kHz to 48kHz in both master and slave modes, making the MAX9850 the easiest to use and most versatile audio DAC available. It can also be operated like traditional synchronous DACs, at any integer-oversampling ratio. The audio DAC receives input data over a flexible 3-wire interface that supports up to 32 bits of left-justified, right-justified, or I2S-compatible audio data. Stereo audio line inputs are provided to either mix analog audio with the digital input stream, or to drive the headphone outputs directly. Mode settings, headphone amplifier volume controls, and shutdown for both the headphone and line outputs are programmed through a 2-wire, I2C-compatible interface. The MAX9850 is fully specified over the -40C to +85C extended temperature range and is available in a lowprofile, 28-pin thin QFN package (5mm x 5mm x 0.8mm).