INDUSTRY'S ONLY INTEGRATED DIRECT I/Q TRANSMITTERS FOR BROADBAND WIRELESS SYSTEMS
Note to Editors: The MAX2720/MAX2721 are the most highly integrated direct I/Q transmitters designed specifically for broadband wireless applications. The direct conversion architecture dramatically reduces size and cost, saving an IF SAW filter, VCO, PLL, and upconverter. This saves 35% in component cost and 50% in board space.
SUNNYVALE, CA—February 15, 2000—Maxim Integrated Products introduces the MAX2720/MAX2721, the industry’s most highly integrated direct I/Q transmitters. Operating from 1.7GHz to 2.5GHz, these transmitters include differential amplifiers for modulation inputs, two matched double-balanced mixers, a selectable LO doubler, an LO buffer, a wideband 90° quadrature generator, an RF variable gain amplifier (VGA) with 35dB control range, and a +13dBm PA driver amplifier. Compared to traditional IF-based architecture, the direct conversion approach eliminates an IF stage, saving an IF SAW filter, VCO, PLL, and upconverter. This reduces component cost by 35% and board space by 50%. The devices are ideal for applications in wideband CDMA systems, wireless local loop (WLL), PCS/DCS base stations, LMDS/MMDS, and 2.4GHz broadband ISM-band radios.
The MAX2720 converts a baseband signal directly up to an RF output frequency range of 1.7GHz to 2.1GHz; the MAX2721 output range is 2.1GHz to 2.5GHz. A logic-enabled frequency doubler allows the user to inject the LO signal at half frequency, resulting in a carrier suppression of 33dB. The I/Q inputs are amplitude-matched to within ±0.2dB and phase-matched to within ±1°C. The excellent amplitude and phase match results in a sideband suppression of 40dB at 1.9GHz (MAX2720) and 35dB at 2.3GHz (MAX2721). To help reduce transmitter noise at the RF output, I/O pins are available for insertion of a bandpass filter between the VGA output and the PA driver input.
The MAX2720/MAX2721 operate on a single +2.7 to +3.3V supply and offer a low-power shutdown mode. Both are available in the 20-pin TSSOP package with exposed paddle.
Pricing starts from $4.55 (1000-up, FOB USA). A fully assembled evaluation kit (MAX2720EVKIT) is available to help reduce design time.
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