Automotive headphone amplifiers protect outputs from shorts to battery and load dump up to 45V

Automotive headphone amps integrate robust output protection and diagnostics.

SUNNYVALE, CA—April 30, 2009—Maxim Integrated Products (NASDAQ: MXIM) introduces the MAX13330/MAX13331 automotive, stereo headphone amplifiers. Designed for automotive entertainment systems in which board space is at a premium and high-voltage protection is paramount, these robust devices protect outputs against shorts to battery/ground and load dump up to 45V. This built-in protection circuitry eliminates the need for the discrete components that perform such protection, resulting in both space and cost savings. They also integrate a short-circuit diagnostic output to facilitate fault analysis, and include ±15kV ESD protection (Human Body Model) on the headphone outputs. These advanced protection and diagnostic features make the MAX13330/MAX13331 the ideal choice for automotive entertainment systems.

The MAX13330/MAX13331 employ Maxim's patented DirectDrive® technology* to dramatically reduce BOM cost and save board space. DirectDrive headphone amplifiers produce a ground-referenced output from a single supply, and therefore do not require a DC bias voltage to be applied to the headphone-jack ground pin. This innovative approach eliminates the need for the large DC-blocking capacitors required by conventional amplifiers, thus enabling the MAX13330/MAX13331 to save up to $0.10 in cost, 150mm² of board space, and 8mm of component height. Moreover, not using DC-blocking capacitors allows improvement of the amplifiers' low-frequency response for successful reproduction of the full range of audio bandwidth with only a 1microfarad or smaller capacitor. This capability is especially important for music playback. Ultimately, the MAX13330/MAX13331 significantly simplify end-product design while maximizing reliability.

The gain of the amplifiers can be set internally (-1.5V/V, MAX13330) or adjusted externally (MAX13331), providing flexibility in audio codec selection. Both devices operate from a single, 4V to 5.5V supply; have a low, 0.009% THD+N; and can deliver up to 75mW per channel into an 8Ω load, 100mW into a 16Ω load, or 130mW into a 32Ω load. An 80dB at 217Hz PSRR allows these devices to operate from noisy digital supplies without an additional linear regulator or filtering. Comprehensive click-and-pop circuitry suppresses audible clicks and pops on startup and shutdown, ensuring fast turn-on/turn-off times without audible glitches. A low-power shutdown mode reduces the supply current to < 2µA.

Fully specified over the -40°C to +105°C AEC-Q100 Level 2 automotive temperature range, the MAX13330/MAX13331 are available in a space-saving, 4mm x 5mm, 16-pin QSOP package. Prices start at $1.00 (1000-up, FOB USA).

Maxim Integrated Products is a publicly traded company that designs, manufactures, and sells high-performance semiconductor products. The Company reported revenue in excess of $2 billion for fiscal 2008. Maxim was founded over 25 years ago with the mission to deliver innovative analog and mixed-signal engineering solutions that add value to its customers' products. To date, it has developed over 5900 products serving the industrial, communications, consumer, and computing markets.