Broadcom BCM4750 GPS解决方案

Broadcom公司的BCM4750是单片GPS接收器IC,集成了高性能的基带处理器和低噪音的CMOS无线电收发前端,能和手机,PDA, 个人导航设备PND以及MP3播放器的主处理器接口,是目前有最高定位性能和最小PCB面积的GPS集成电路.本文介绍了BCM4750的主要性能,方框图以及应用方框图.

BCM4750 Single-Chip AGPS Solution
The BCM4750 is a single-chip, single-die GPS receiver IC fabricated on 90 nm RFCMOS technology. The BCM4750 integrates a high-performance baseband section with a low-noise CMOS radio front end. It is designed to interface with host processors in mobile phones, PDAs, Personal Navigation Devices (PNDs), and MP3 players. The BCM4750 is a host-based GPS IC that delivers the highest positioning performance yet uses the smallest PCB area in the market today.

Broadcom provides a software library that realizes the GPS navigation solution in the host using minimum resources and with no real time requirements. The BCM4750 uses a patent pending innovative RF design that improves both current consumption and LNA linearity as well as allowing for a minimum number of external components used.

主要特性:
Single-chip solution (AGPS baseband and CMOS RF frontend integrated on a single-die) minimizing board space footprint (<35 sq mm2 PCB area for a complete AGPS solution)
Up to 2-Hz update rate
Real-time hardware correlator engine (fast acquisition and high-sensi tivity) capable of tracking 24 satel l i tes simultaneously
Built-in voltage regulators supporting single power supply source up to 3.6V
Multiple mode operation
MS-based (calculation of position in mobile handset)
MS-assisted (calculation of position in base station)
Autonomous (no assistance by network)
Enhanced autonomous (position computed at mobile device using multi-day Long Term Orbits (LTO&#8482;)

BCM4750的优势:
Advanced low-power RFCMOS technology and low-power tracking at 15 mW for the longest battery life
Host communication via two-wire UART, I2C, or SPI with baud rates as low as 9.6 Kbps
High-sensitivity, -157 dBm assisted acquisition sensitivity (with coarse time assistance) and -162 dBm tracking sensitivity, enabling indoor and deep urban operation
Broadcom software provides protocol layers for control plane (RRLP and RRC) as well as user plane (SUPL)
Autonomous cold start TTFF 30 s
Exceeds 3GPP TS 25.171 and 3GPP2 TS C.S0036 performance requirements
Packages
BGA (5 x 5 mm)
CSP (3.6 x 3.6 mm)



图1. BCM4750外形图