SmartSense自動モノ/ステレオ切替え付、次世代DirectDriveヘッドフォンアンプ
SUNNYVALE, CA-May 6, 2003-Maxim Integrated Products
(NASDAQ: MXIM) introduces the MAX9720 headphone amplifier optimized for portable applications. The MAX9720 audio amplifier combines Maxim's patented DirectDrive architecture, low 5mA supply current, and SmartSense, an automatic mono/stereo switching feature.
SmartSense is a new feature that automatically detects the presence of a short at either output. Under a fault condition, the shorted output is automatically disabled and the stereo input signal is automatically mixed and routed to the remaining active channel. This feature is useful in cell phones, PDAs, and notebooks where headphone jacks with unknown loads can be inserted into the headphone jack socket. SmartSense provides automatic mono/stereo switching, eliminates battery drain into a shorted load, and prevents damage to the amplifier.
Conventional headphone amps require a bulky DC-blocking capacitor between the headphone and the amplifier. DirectDrive produces a ground-referenced output from a single supply, eliminating the need for the large DC- blocking capacitors, saving cost, board space, and component height.
The MAX9720 operates from a single 1.8V to 3.6V supply, has ultra-low 0.003% THD + N, and delivers up to 50mW per channel into a 16 load. A high 92dB power-supply rejection ratio allows operation from noisy digital supplies without additional power conditioning. Two preset gain options are available (0dB for MAX9720A, 3dB for MAX9720B), eliminating the need for external gain setting resistors and simplifying system design. The headphone outputs include comprehensive click-and-pop circuitry to eliminate audible glitches on startup and shutdown. A shutdown mode provides a fast 250µs turn-on time.
The MAX9720 is available in a tiny (2mm x 2mm x 0.6mm), 16-bump chip-scale package (UCSP™) and a 16-pin TSSOP package, both specified over the extended (-40° C to +85° C) temperature range. Prices for the MAX9720AEBE-T start at $0.80 (100k-up, FOB USA).
UCSP is a trademark of Maxim Integrated Products, Inc.
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