博通(Broadcom)公司的BCM4325是有最高集成度的单片低功耗器件,它集成了802.11a/b/g(MAC/基带/无线电),蓝牙2.1+增强数据速率(EDR)以及FM接收器,最大限度地降低了外接元件和成本,为移动或手持无线系统提供了小型解决方案. BCM4325能实现高度专业的无线电共存算法和硬件机理,支持外接无线电如GPS,WiMAX,超宽带无线电技术以及蜂窝无线电),同时共享同一天线.本文主要介绍了BCM4325的主要特性,包括WLAN主要特性,蓝牙主要特性,通用特性以及技术指标与方框图.
BCM4325: Low-Power 802.11a/b/g with Bluetooth® 2.1 + EDR and FM
The Broadcom BCM4325 family of single-chip devices provides for the highest level of integration for a mobile or handheld wireless system, with integrated IEEE 802.11a/b/g (MAC/Baseband/Radio), Bluetooth 2.1 + enhanced data rate (EDR), and FM receiver. Thus providing a compact small form factor solution with minimal external components to
drive the costs for mass volumes and allows for flexibility in size, form, and function of handheld devices. The BCM4325 is designed to address the needs of highly mobile devices that require minimal power consumption and reliable operation.
The BCM4325 utilizes advanced design techniques and process technology to deliver the lowest active and idle power, extending the system battery life while maintaining consistent connectivity, and still provides a rich set of features.
The BCM4325 implements the highly sophisticated InConcert radio coexistence algorithms and hardware mechanisms allowing for an extremely collaborative coexistence scheme along with coexistence support for external radios (such as GPS, WiMax, or Ultra Wide-Band radio technologies, as well as cellular radios) and a single shared Antenna. As a result, it enhances the overall quality for simultaneous voice, video, and data  transmission on a handheld system while minimizing the footprint.
The BCM4325 further integrates a power management unit simplifying the power topology on a system and allowing for operation directly from the handheld battery. It also integrates a CMOS power amplifier to meet the requirements of most handheld systems while permitting an external power amplifier for high-power applications.
BCM4325 Specifications

主要特性:
WLAN Key Features
Single-band 2.4-GHz 802.11b/g or dual-band 2.4-GHz and 5-GHz 802.11a/b/g with Bluetooth 2.1 + EDR and FM receiver
Industry leading low-active transmit and receive power consumption and ultra-low power in stand-by and idle modes
Supports IEEE 802.11d/e (WMM, QoS, WMM-PS), h, i, j (upgrades available for k, r, w)
Supports IEEE 802.15.2 external three wire coexistence scheme to support additional wireless technologies such as GPS, WiMax, or UWB
Supports standard interfaces, SDIO v1.2 (1 bit and 4 bit), SPI, and high speed UART, for easy migration from the Broadcom 2 chip solution (BCM4328 + BCM2048)
Integrated CPU with on-chip memory for a complete WLAN subsystem minimizing the need to wake up the applications processor
Fractional nPLL allows support for a wide range of reference clock frequencies
Security:
WPA- and WPA2 (personal) for powerful encryption and authentication
AES and TKIP in hardware for faster data encryption and 802.11i compatibility
Supports Cisco® Compatible Extensions (CCX - CCX4.0)
SecureEasySetup for simple Wi-Fi setup and WPA2/ WPA security configuration
Worldwide regulatory support—Global products supported with worldwide homologated design
Bluetooth Key Features
Bluetooth Specification version 2.1 + EDR (up to 3 Mbps) compliant, with provisions for supporting future specifications
Supports extended synchronous connections (eSCO) for enhanced voice quality by allowing for retransmission of dropped packets
Adaptive frequency hopping (AFH), for reducing radio frequency interference.
Interfaces support—Host controller interface (HCI) using a high-speed UART interface and PCM for audio data
The FM unit supports BSC (Broadcom Serial Control) for communications, stereo analog output, as well as I²S and PCM interfaces.
Integrates the InConcert collaborative WLAN coexistence, including the 802.15.2 three-wire coexistence support
Low-power consumption improves battery life of handheld devices
76-MHz to 108-MHz FM bands and supports European Radio Data Systems (RDS) and North American Radio Broadcast Data Systems (RBDS) modulations
Supports dual-A2DP for stereo sound
Automatic frequency detection for standard crystal and TCXO values
General Features
One driver software architecture for easy migration from existing embedded WLAN and Bluetooth devices as well as future devices
Support battery voltage range from 2.3V to 5.5V supplies with the internal switching regulator




图1.BCM4325方框图