原标题：Microchip MRF24XA 2.4GHz RF收发器解决方案

　　microchip公司的MRF24XA是IEEE 802.15.4兼容的2.4GHz RF收发器,在单片上集成了PHY和MAC功能,能实现最低成本低功耗高数据速率(125kbps-2Mbps)无线个人局域网(WPAN),可配置的发送功率-17.5 到0 dBm,工作电压1.5V到3.6V,主要用在工业监视和控制,IEEE 1588协议网络,自动读表,家庭自动化,低功耗无线传感器网络,消费类电子,语音和音频.本文介绍了MRF24XA主要特性,无线节点框图,架构框图,应用电路图以及MRF24XA PICtail™/PICtail Plus子板主要特性,电路图,材料清单和PCB设计文件.

　　MRF24XA is an IEEE 802.15.4™ Standard compliant2.4 GHz RF transceiver with feature extensions.

　　MRF24XA integrates the PHY and MAC functionality ina single chip solution. MRF24XA implements a lowcost,low-power, high data rate (125 kbps to 2 Mbps)Wireless Personal Area Network (WPAN) device. Allthe data rates have the same spectral shape requiring identical bandwidth. At 125 kbps data rate DirectSequence Spread Spectrum (DSSS) is combined witherror correction and coding for maximum range androbustness against interference. The 2 Mbps data ratecan be used to minimize radio ON-time, therefore extending battery life.

　　MRF24XA interfaces to many popular Microchip PIC®microcontrollers through a 4-wire serial SPI interface,interrupt, GPIO, and RESET pins.MRF24XA can also handle external Power Amplifier(PA) and Low Noise Amplifier (LNA).

　　MRF24XA provides hardware support for:

　　• Energy detection

　　• Carrier sense

　　• Four CCA modes

　　• CSMA-CA algorithm

　　• Automatic packet retransmission

　　• Automatic acknowledgement

　　• Independent transmit and receive buffers

　　• Security engine supports encryption anddecryption for MAC sublayer and upper layer

　　• Inferred destination addressing

　　• Channel agility with ACKs

　　• Battery monitoring

　　These features reduce the processing load, allowingthe use of low-cost 8-bitmicrocontrollers.

　　MRF24XA is compatible with Microchip’s ZigBee®,MiWi™ and MiWi P2P software stacks. Each softwarestack is available as a free download, including sourcecode, from the Microchip web site: http://www.microchip.com/wireless

　　MRF24XA主要特性:

　　• IEEE 802.15.4™-2003 and IEEE 802.15.4-2006Standard Compliant RF transceiver

　　• Multiple air data rates:

　　- 250 kbps (IEEE 802.15.4)

　　- 125, 500, 1000, 2000 kbps, co-existence withstandard networks

　　• Configurable TX output power: -17.5 to 0 dBm

　　• Frame header duration scales with the selecteddata rate

　　• On-the-fly, per-frame air-data-rate detection(link-by-link independent air data rates)

　　• Inferred destination addressing (to further save onframing overheads; optional)

　　Full Featured MCU Support

　　• Hardware frame parser

　　• Hardware CSMA-CA controller, automaticacknowledgement (ACK) and Frame Check

　　Sequence (FCS)

　　• Supports all Clear Channel Assessment (CCA)modes

　　• Reports ED, RSSI, LQI, and CFO

　　• Channel Agility with acknowledgements

　　• Two independent 128 byte frame buffers

　　• Streaming mode to maximize throughput

　　• Automatic Packet retransmit Capability

　　• Hardware Security Engine (AES-128) andconfigurable Encryption/Decryption mode

　　Low-Power

　　• Extreme minimization of radio ON-time

　　- Highest channel-admissible data rate used

　　- 20%-70% overall reduction through framing

　　• 2 Mbps frames can reduce radio ON-time by a factorof 4 to 8 with respect to 250 kbps frames

　　• 25 mA TX current (typical at 0 dBm)

　　• 13.5 mA RX current in RX Listen Power-Saving mode

　　• 15.5-16.5 mA RX current in RX Packet Demodulationmode (data rate and device configuration dependent)

　　• Deep Sleep, Sleep, Crystal ON, RX Listen

　　Power-Saving modes

　　• Memory retention in Deep Sleep (<40 nA typical)

　　• Automated functions minimize MCU ON-time

　　General

　　• Low external component count

　　• Best-in-class battery life preservation

　　• Supply range: 1.5V to 3.6V

　　• Compact 32-pin 5x5 mm2 QFN package

　　• Temperature range -40oC to +85oC

　　• Certified turnkey-ready solutions available

　　MRF24XA应用:

　　• IEEE 802.15.4/ZigBee® systems (RF4CE, and soon)

　　• Industrial monitoring and control

　　• IEEE 1588 precise timing protocol networks

　　• Automatic meter reading

　　• Home building automation

　　• Low-power wireless sensor networks

　　• Consumer electronics, voice and audio

　　图1.MRF24XA无线节点框图

　　MRF24XA PICtail™/PICtail Plus子板

　　The MRF24XA PICtail™/PICtailPlus Daughter Board is a demonstration anddevelopmentboard for low-power, 2.4 GHz ISM-Band IEEE 802.15.4™ RF Transceiver.

　　The MRF24XA PICtail™/PICtailPlus Daughter Board can be plugged into Microchip’s many demonstration and development boards. For example, the MRF24XA PICtail™/PICtailPlus Daughter Board is appropriate for 8-bit microcontroller development using the PIC18 Explorer Development Board(DM183032) or for 16-bit or 32-bit microcontroller development using the Explorer 16 Development Board (DM240001).

　　图.MRF24XA PICtail™/PICtail Plus子板外形图

　　图. MRF24XA PICtail™/PICtail Plus子板插入PIC18 Explorer开发板图

　　MRF24XA PICtail™/PICtail Plus子板材料清单: