300MHz TO 450MHz SUPERHETERODYNE ASK/FSK RECEIVER WITH INTEGRATED IMAGE REJECTION OPERATES FROM 3V OR 5V SUPPLY
SUNNYVALE, CA-May 12, 2004-Maxim Integrated Products (NASDAQ: MXIM) introduces the MAX1471, the industry's first dual-channel receiver that can receive both ASK and FSK data simultaneously, eliminating the switching lag time between modes. Designed for low-cost systems where both encoding schemes are present, the MAX1471 also includes a discontinuous receive (DRX) feature for low-power duty-cycle operation. The DRX feature is user configurable through a serial interface (SPI™) bus. The DRX mode also allows self-polling, where the MAX1471 can stay in sleep mode as long as eight minutes and can also be used to wake the system microprocessor, thus offering additional cost and power savings. The MAX1471 operates from 300MHz to 450MHz and includes an on-chip 45dB (typ) image-rejection mixer, which eliminates the need for SAW filters in many applications. The device operates from either a 3.3V or 5V supply, down to 2.4V.
The MAX1471 features high sensitivities of -114dBm (ASK) and
-108dBm (FSK). It has a low-noise amplifier (LNA), an image-reject (IR) mixer, a fully integrated phase locked loop (PLL), local oscillator (LO), a 10.7MHz IF limiting amplifier with received-signal-strength indicator (RSSI), a low-noise FM demodulator, and a 3.0V voltage regulator. Differential peak-detecting data demodulators are included for both FSK and ASK analog baseband data recovery.
The MAX1471 is designed to operate in a wide variety of power-sensitive applications such as remote-keyless-entry systems, car alarms, tire-pressure monitoring systems, home-security systems, remote controls, and garage-door openers. The part draws less than 1.1µA in shutdown mode and only 7.0mA in receive mode. Depending on the components selected, the MAX1471 is capable of receiving data rates up to 33kbps (Manchester) or 66kbps (NRZ), and transitions from shutdown to valid data out in less than 250µs. In power-cycled applications, this quick transition minimizes how long the system needs to be in receive mode.
The MAX1471 comes in a 32-pin thin TQFN, and operates over the automotive temperature range (-40°C to +125°C). Prices start at $2.39 (10,000-up, FOB USA).
SPI is a trademark of Motorola, Inc.
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