MAX9729 Datasheet | Maxim Integrated

Description The MAX9729 stereo Direct Drive™ headphone amplifier features bass boost, volume control, an input mux, and an I2C/SMBus™-patible serial interface. This makes the MAX9729 ideal for portable audio applications where space is at a premium and performance is essential. The MAX9729 operates from a single 1.8V to 3.6V, and uses Maxim’s patented† Direct Drive architecture, eliminating the need for large DC-blocking capacitors. The headphone amplifiers deliver 52m W into a 32Ω load, feature low 0.03% THD+N, and high 90d B PSRR. Maxim’s industry-leading click-and-pop suppression circuitry reduces audible transients during power and shutdown cycles. The Bass Max feature boosts the bass response of the amplifier, improving audio reproduction for low-end headphones. The integrated volume control features 32 discrete volume levels along with a ramping function to ensure smooth transitions during shutdown cycles and input selection. The MAX9729’s eight programmable maximum gain settings allow for a wide range of input signal levels. A 3:1 multiplexer/mixer allows the selection and summation of multiple stereo input signal sources. The MAX9729 also includes a dedicated BEEP input with independent attenuation control. Bass Max, volume control, gain settings, and input selection are controlled using the I2C/SMBus-patible serial interface. A lowpower, 5µA shutdown mode is controlled through an external logic input or the serial interface. The MAX9729 consumes only 4.8m A of supply current, provides short-circuit and thermal-overload protection, and is specified over the -40°C to +85°C extended temperature range. The MAX9729 is available in a spacesaving 28-pin thin QFN package (5mm x 5mm x 0.8mm). Pin Configuration appears at end of data sheet. Features - Direct Drive Headphone Amplifier Eliminates Bulky DC-Blocking Capacitors - 3:1 Input Multiplexer with Digital-Fade Circuitry - Software-Enabled Bass Boost - 32-Step Integrated Volume Control - Beep Input with Programmable...