基于MAX2769设计的全球导航卫星系统（GNSS）接收方案

The MAX2769 is the industry’s first global navigation satellite system (GNSS) receiver covering GPS, GLONASS, and Galileo navigation satellite systems on a single chip. This single-conversion, low-IF GNSS receiver is designed to provide high performance for a wide range of consumer applications, including mobile handsets.

Designed on Maxim’s advanced, low-power SiGe BiCMOS process technology, the MAX2769 offers the highest performance and integration at a low cost.

Incorporated on the chip is the complete receiver chain, including a dual-input LNA and mixer, followed by the image-rejected filter, PGA, VCO, fractional-N frequency synthesizer, crystal oscillator, and a multibit ADC. The total cascaded noise figure of this receiver is

as low as 1.4dB.

The MAX2769 completely eliminates the need for external IF filters by implementing on-chip monolithic filters and requires only a few external components to form a complete

low-cost GPS receiver solution.

The MAX2769 is the most flexible receiver on the market. The integrated delta-sigma fractional-N frequency synthesizer allows programming of the IF frequency within a ±40Hz accuracy while operating with any reference or crystal frequencies that are available in the

host system. The integrated ADC outputs 1 or 2 quantized bits for both I and Q channels, or up to 3 quantized bits for the I channel. Output data is available either at the CMOS logic or at the limited differential logic levels.

The MAX2769 is packaged in a compact 5mm x 5mm, 28-pin thin QFN package with an exposed paddle. The part is also available in die form. Contact the factory for further information.

主要特性：

_ GPS/GLONASS/Galileo Receivers

_ No External IF SAW or Discrete Filters Required

_ Programmable IF Frequency

_ Fractional-N Synthesizer with Integrated VCO Supports Wide Range of Reference Frequencies

_ Dual-Input Uncommitted LNA for Separate Passive and Active Antenna Inputs

_ 1.4dB Cascade Noise Figure

_ Integrated Crystal Oscillator

_ Integrated Active Antenna Sensor

_ 10mA Supply Current in Low-Power Mode

_ 2.7V to 3.3V Supply Voltage

_ Small, 28-Pin, RoHS-Compliant, Thin QFN Lead- Free Package (5mm x 5mm)

MAX2769应用：

Location-Enabled Mobile Handsets

PNDs (Personal Navigation Devices)

PMPs (Personal Media Players)

PDAs (Personal Digital Assistants)

In-Vehicle Navigation Systems

Telematics (Asset Tracking, Inventory

Management)

Recreational/Marine Navigation/Avionics

Software GPS

Laptops and Ultra-Mobile PCs

Digital Still Cameras and Camcorders

图1。MAX2769典型应用电路

元件列表：

图2。DSP顶层连接接口和控制信号框图

MAX2769评估板

The MAX2769 evaluation kit (EV kit) simplifies evaluation of the MAX2769 universal GPS receiver. It enables testing of the device performance and requires no additional support circuitry. Standard 50SMA connectors are included on the EV kit for the inputs and

outputs to allow for quick and easy evaluation on the test bench. The evaluation kit is fully assembled and tested at the factory.

This document provides a component list, a list of equipment required to evaluate the device, a straightforward test procedure to verify functionality, a description of the EV kit circuit, the circuit schematic, and artwork for each layer of the printed-circuit board (PCB).

MAX2769评估板主要特性：

♦ Easy Evaluation of the MAX2769 IC

♦ +2.7V to +3.3V Single-Supply Operation

♦ 50SMA Connector on the RF Ports and for the Baseband Outputs

♦ All Critical Peripheral Components Included

♦ Parallel Port for 3-Wire Interfacing

♦ PC Control Software Available Upon Request

图3。MAX2769评估板电路图

MAX2769评估板元件列表：

图4。MAX2769评估板顶层PCB布局图