315MHz/433MHz ASK Superheterodyne Receiver with Extended Dynamic Range

The MAX1473 fully integrated low-power CMOS superheterodyne receiver is ideal for receiving amplitude-shift-keyed (ASK) data in the 300MHz to 450MHz frequency range. Its signal range is from -114dBm to 0dBm. With few external components and a low-current power-down mode, it is ideal for cost- and power-sensitive applications typical in the automotive and consumer markets. The chip consists of a low-noise amplifier (LNA), a fully differential image-rejection mixer, an on-chip phase-locked-loop (PLL) with integrated voltage-controlled oscillator (VCO), a 10.7MHz IF limiting amplifier stage with received-signal-strength indicator (RSSI), and analog baseband data-recovery circuitry. The MAX1473 also has a discrete one-step automatic gain control (AGC) that drops the LNA gain by 35dB when the RF input signal is greater than -57dBm.

The MAX1473 is available in 28-pin TSSOP and 32-pin thin QFN packages. Both versions are specified for the extended (-40°C to +85°C) temperature range.

Applications

* Automotive Remote Keyless Entry (RKE) * Garage Door Openers * Home Automation * Local Telemetry Systems * Remote Controls * Security Systems * Wireless Sensors

* Optimized for 315MHz or 433MHz ISM Band

* Operates from Single 3.3V or 5.0V Supplies

* High Dynamic Range with On-Chip AGC

* Selectable Image-Rejection Center Frequency

* Selectable x64 or x32 fLO/fXTAL Ratio

* Low 5.2mA Operating Supply Current

* < 2.5µA Low-Current Power-Down Mode for Efficient Power Cycling

* 250µs Startup Time

* Built-In 50dB RF Image Rejection

* Receive Sensitivity of -114dBm