MAXIM Integrated Products, represented by Arrow Electronics , has introduced the MAX4411B headphone amplifier, which combines Maxim's patented stereo DirectDrive technology with a fixed-gain (-2V/V) configuration.
This combination eliminates both the bulky dc-blocking capacitors and the external-gain setting resistors.
The result is a low-cost, ultra-compact headphone amp requiring very few external components and making it suitable for compact, portable equipment with audio playback.
DirectDrive generates a ground-referenced output from a single 1.8V to 3.6V supply, which unlike competing solutions, does not require a mid-rail dc bias voltage to be applied to the headphone jack ground pin.
This doubles the dynamic range of the output swing and simplifies end product design and reliability.
The MAX4411B has a fixed gain of -2V/V, produces 80mW per channel into a 16 ohm load, and has very low 0.003% THD + N. A high 86dB PSRR @ 217Hz allows direct operation from noisy supplies without additional conditioning.
Independent left/right, low-power shutdown controls optimise power savings in mixed mode mono/stereo applications.
In addition to minimising size, the elimination of dc-blocking capacitors improves the amplifier's low-frequency response, allowing full-range audio reproduction.
This is especially important for music and video playback. Comprehensive click-and-pop reduction circuitry ensures fast turn on/turn off times without audible glitches. The outputs include ±8kV ESD protection.
The MAX4411B is available in a tiny, 16-bump chip-scale-package (UCSP(TM)) (2mm x 2mm x 0.6mm) and a 20-pin QFN (4mm x 4mm x 0.8mm), making them suitable for cell phones, smart phones, MP3 players, PDAs, notebook computers, DVDs, and general portable audio applications.
Specifications are guaranteed over a -40ºC to +85ºC temperature range.