|
NEXT-GENERATION DirectDrive HEADPHONE AMP OFFERS DIFFERENTIAL INPUTS AND 5V OPERATION
SUNNYVALE, CA-November 10, 2003-Maxim Integrated Products (NASDAQ: MXIM) continues expanding its DirectDrive headphone amplifier series with the MAX9722A and MAX9722B devices. The MAX9722 employs a revolutionary architecture that produces a ground-referenced output from a single supply. This eliminates the two bulky DC-blocking capacitors that are typically required between the amplifier and headphone. The MAX9722 is ideal for portable audio equipment where board space and height are critical. Like Maxim's other DirectDrive headphone amps, the MAX9722 does not require a DC bias voltage to be applied to the headphone-jack ground pin, thus significantly simplifying end-product design and reliability.
The differential input structure of the MAX9722 allows the amplifier to reject common-mode noise present in a system. The device can also be configured to sense the headphone return potential, eliminating noise caused by ground loops. The gain of the MAX9722B is set internally to -6dB, which minimizes external components, while the gain of the MAX9722A is set with two external resistors.
The MAX9722 operates from a single 2.4V to 5.5V supply, provides 60mW per channel into a 16 load, and has only 0.02% THD + N. The device provides 130mW per channel into a 32 load. High, 90dB PSRR allows the amplifier to operate directly from noisy supplies without the need for additional LDOs or filtering. To optimize power savings, a low-power shutdown mode reduces supply-current consumption to below 100µA. Additionally, eliminating the DC-blocking capacitors improves the amplifier's low-frequency response, allowing full-range audio reproduction-especially important for music and video playback. Comprehensive click-and-pop suppression circuitry ensures fast turn-on/turn-off times without audible glitches. The outputs feature ±8kV ESD protection.
The MAX9722 is available in tiny 16-pin QFN (3mm x 3mm x 0.8) and 16-pin TSSOP packages making them ideal for cell phones, smart phones, MP3 players, PDAs, notebook computers, DVD, and general portable audio applications. Specifications are guaranteed over a -40°C to +85°C temperature range. An easy-to-use evaluation kit is available to speed designs. Prices start at $0.65 (100,000-up, FOB USA).
|