Single-Chip Global Positioning System Front-End Downconverter

The MAX2745 complete single-chip global positioning system (GPS) RF front-end downconverter utilizes many innovative and leading-edge RF CMOS design techniques. This high-performance, state-of-the-art device consumes extremely low power and eliminates the need for costly SAW and bulky discrete IF filters. The MAX2745 incorporates a fully integrated low-noise amplifier (LNA), IF section, digital sampler, and local oscillator synthesizer. The MAX2745 implements power-down control for an external LNA as well as active antenna detection. In addition, the MAX2745 features a voltage booster, which can extend the power-supply voltage to as low as 1.6V.

The MAX2745 supports both 3rd overtone crystal designs in 32MHz and fundamental frequency crystal designs in 16MHz, as well as TCXO implementation. In addition, the MAX2745 incorporates an on-chip temperature sensor and voltage-controlled oscillator (VCO) with trimmed capacitors, resulting in a very accurate frequency and additional system cost savings.

The MAX2745 is available in a space-saving 48-pin TQFP package and is specified for the extended (-40°C to +85°C) temperature range. The power consumption of this device is as low as 41mW at 2.4V.

Applications

* Consumer Electronics * Digital Cameras and Camcorders * Emergency Response Systems * Emergency Roadside Assistance * Geographical Information Systems (GISs) * In-Vehicle Navigation Systems (IVNS) * Location-Based Services (PDAs and Accessories) * Recreational Handheld/Walkie Talkies * Telematics (Vehicle and Asset Tracking, Inventory Management)

* Complete Single-Chip GPS Radio for 16.368MHz and 32.736MHz Floorplans

* Single-Ended or Differential Outputs at 4.092MHz

* Low 3.5dB Typical Noise Figure

* No External IF SAW or Discrete Filters Required

* On-Chip Temperature Sensor

* 2.4V to 3.6V Operational Supply Voltage Range

* Power Consumption as Low as 41mW at 2.4V

* Wide -40°C to +85°C Operational Temperature Range