浅谈Atmel AT86RF230 2.4 GHz无线收发方案

　　Atmel公司的AT86RF230是低功耗的2.4 GHz无线电收发器，是真正的SPI到天线的解决方案，设计用于ZigBee/IEEE 802.15.4.单片内集成了除天线，晶体和去耦电容外所有的RF关键元件。 AT86RF230可编程输出功率从-17dBm到高达 3dBm,接收器灵敏度为-101dBm,工作电压从1.8V到3.6V,并集成了内部稳压器，稳压器，顾名思义，就是使输出电压稳定的设备。所有的稳压器，都利用了相同的技术实现输出电压的稳定输出电压通过连接到误差放大器（Error Amplifier）反相输入端（Inverting Input）的分压电阻（Resistive Divider）采样（Sampled），误差放大器的同相输入端（Non-inverting Input）连接到一个参考电压Vref。 参考电压由IC内部的带隙参考源（Bandgap Reference）产生。 误差放大器总是试图迫使其两端输入相等。为此，它提供负载电流以保证输出电压稳定。稳压器：它是一种能自动调整输出电压的供电电路或供电设备，其作用是将波动较大和不合用电器设备要求的电源电压稳定在它的设定值范围内，使各种电路或电器设备能在额定工作电压下正常工作。大型的几十至几百千瓦的电力稳压器，是供给大型实验设备的工作电源。也有小型的几瓦到几千瓦的交流稳压器，是为小型实验室或家庭电器提供高质量电源，

　　The AT86RF230 is a low-power 2.4 GHz radio transceiver especially designed for ZigBee/IEEE 802.15.4 applications. The AT86RF230 is a true SPI-to-antenna solution.All RF-critical components except the antenna, crystal and de-coupling capacitors are integrated on-chip. Therefore, the AT86RF230 is particularly suitable for applications like:

　　2.4 GHz IEEE 802.15.4 and ZigBee systems

　　6LoWPAN and RF4CE systems

　　Wireless sensor networks

　　Industrial control, sensing and automation （SP100, WirelessHART）

　　Home and building automation

　　Consumer electronics

　　PC peripherals

　　The AT86RF230 can be operated by using an external microcontroller like ATMEL’s AVR microcontrollers. A comprehensive software programming description can be found in the application note AVR2009 “AT86RF230 – Software Programming Model”。

　　This single-chip radio transceiver provides a complete radio transceiver interface between the antenna and the microcontroller. It comprises the analog radio transceiver and the digital demodulation including time and frequency synchronization, and data buffering. The number of external components is minimized such that only an antenna, a crystal and four decoupling capacitors are required. The bidirectional differential antenna pins are used for transmission and reception, so that no external antenna switch is needed.

　　AT86RF230主要特性：

　　High Performance RF-CMOS 2.4 GHz Radio Transceiver Targeted for IEEE 802.15.4?, ZigBee?, 6LoWPAN, RF4CE, SP100, WirelessHART? and ISM Applications

　　Industry Leading Link Budget （104 dB）：

　　- Programmable Output Power from -17 dBm up to 3 dBm

　　- Receiver Sensitivity -101 dBm

　　Ultra-Low Power Consumption:

　　- SLEEP: 20 nA

　　- RX: 15.5 mA

　　- TX: 16.5 mA （at max Transmit Power of 3 dBm）

　　Ultra-Low Supply Voltage （1.8V to 3.6V） with Internal Regulator

　　Optimized for Low BoM Cost and Ease of Production:

　　- Few External Components Necessary （Crystal, Capacitors and Antenna）

　　Excellent ESD Robustness

　　Easy to Use Interface:

　　- Registers and Frame Buffer Accessible through Fast SPI

　　- Only Two Microcontroller GPIO Lines Necessary

　　- One Interrupt Pin from Radio Transceiver

　　- Clock Output with Prescaler from Radio Transceiver

　　Radio Transceiver Features:

　　- 128-byte SRAM for Data Buffering

　　- Programmable Clock Output to Clock the Host Microcontroller or as Timer Reference

　　- Integrated TX/RX Switch

　　- Fully Integrated PLL with on-chip Loop Filter

　　- Fast PLL Settling Time

　　- Battery Monitor

　　- Fast Power-Up Time < 1 ms

　　Special IEEE 802.15.4-2003 Hardware Support:

　　- FCS Computation

　　- Clear Channel Assessment

　　- Energy Detection / RSSI Computation

　　- Automatic CSMA-CA

　　- Automatic Frame Retransmission

　　- Automatic Frame Acknowledgement

　　- Automatic Address Filtering

　　Industrial Temperature Range:

　　- -40℃ to 85℃

　　I/O and Packages:

　　- 32-pin Low-Profile QFN

　　- RoHS/Fully Green

　　Compliant to EN 300 328/440, FCC-CFR-47 Part 15, ARIB STD-66, RSS-210

　　Compliant to IEEE 802.15.4-2003

　　图1.AT86RF230方框图

　　图2.AT86RF230应用电路图

　　RZ600评估板

　　The RZ600 evaluation kit enables development, debugging and demonstration of IEEE 802.15.4 compliant wireless applications such as ZigBee and 6LoWPAN. The kit is FCC certified and contains evaluation boards for AT86RF212 and the AT86RF23x families of RF transceivers covering the regional 700/800/900MHz and worldwide 2.4GHz ISM bands for use with STK600.

　　The kit also contains two USB adapters equipped with UC3A 32-bit AVR microcontrollers for standalone point-point or packet sniffer operation。

　　图3.RZ600评估板外形图

　　图4.RZ600无线电电路图

　　图5.RZ600 USB适配器电路图