General Description

The MAX2740 is a complete global positioning system (GPS) receiver from antenna output to digitizer input. The signal path includes the LNA, two downconverters, and variable-gain and fixed-gain amplifiers. By utilizing a double-conversion superheterodyne architecture with external surface acoustic wave (SAW) filters, high levels of image rejection and blocking immunity are possible. Receiver linearity has been maximized to improve operation in hostile RFI environments found in cellular base stations. The MAX2740 also includes a high-performance voltage-controlled oscillator (VCO) with low phase noise for subcentimeter carrier phase applications, and a fixed-frequency synthesizer for generation of all required on-chip local oscillators.

The unique frequency plan captured in the MAX2740 is suitable for joint GPS/GLONASS receivers with minimal external components. This allows the MAX2740 to provide a cost-effective and high-performance solution for navigation and timing products that need maximum satellite availability.

The MAX2740 is compatible with a high-performance DSP engine capable of very fast time to first fix and excellent multipath rejection.

Features

♦ High Selectivity for Hostile Base Station Environments

♦ Complete Antenna-to-Baseband Receiver Solution

♦ >100dB Total Receiver Gain Including All Filter Losses

♦ >50dB Automatic Gain Control (AGC) Range

♦ Fully Balanced Topology for Minimum Spurious Responses

♦ Low Phase Noise VCO for Carrier Phase Applications

♦ Compatible with High-Performance Companion DSP

Applications

  Base Station Timing

  E911 Location Assistance

  GPS Automotive and Consumer Receivers

  Wireless Local-Loop Timing

  Joint GPS/GLONASS Receivers

  High-Precision Timing for SDH Networks

  High-Positional-Accuracy Surveying Equipment