Low-EMI, Filterless Class D Audio Amplifier Ideal for Portable Applications
SUNNYVALE, CA-August 14, 2003-Maxim Integrated Products (NASDAQ: MXIM) introduces the MAX9712 highly efficient, filterless Class D audio amplifier. The MAX9712 offers Class AB circuit simplicity (no output filters) and Class AB audio performance (0.06% THD+N), combined with 90% Class D efficiency. The device employs a patented modulation scheme that meets FCC Radiated Emissions Standards without the need for an output filter or ferrite beads. This results in a low-cost, ultra-compact, highly efficient audio amplifier requiring very few external components. The MAX9712 is ideal for compact, portable equipment such as cell phones and PDAs.
The MAX9712 operates over a 2.4V to 5.5V supply, has a fixed gain of 12dB, and produces up to 500mW per channel into an 8Ω load. High 70dB PSRR at 217Hz allows operation directly from a single lithium-ion cell without the need for additional supply conditioning. The MAX9712 includes four clocking options to optimize the noise spectrum for a given application. These include three internally generated clock rates and a fourth unique external-clock mode, allowing the user to control the exact placement of the switching energy. In addition, multiple MAX9712's can operate in a master/slave configuration, making it possible to easily configure two amplifiers for stereo operation while eliminating clock noise interaction. Comprehensive click-and-pop reduction circuitry ensures fast turn-on/turn-off times without audible glitches.
The MAX9712 is available in tiny 12-pin UCSP™ (1.5mm x 2mm x 0.6mm), 10-pin DFN (3mm x 3mm x 0.8mm), and 10-pin µMAX (3mm x 5mm x 1mm) packages. The device is specified to operate over the -40°C to +85°C temperature range. Prices for the MAX912EUB start at $0.39 (100k-up, FOB USA).
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