AT86RF212低功耗ZigBee收发方案

Atmel AT86RF212低功耗ZigBee收发方案

2009-11-16 22:56出处：中华电子网作者：美国爱特梅尔公司【我要评论】

Atmel 公司的AT86RF212是低功耗低电压700/800/900 MHz 收发器,特别设计

用于IEEE Standard 802.15.4, ZigBee, 6LoWPAN以及高数据速率ISM应用。

AT86RF212单片RF收发器提供了天线和微控制器间完整接口,包括有模拟无线电部

分,包括时间和频率同步的数字调制和解调, 以及数据缓冲功能。接收灵敏度高达

-110dBm,可编程TX输出功率高达+10dBm,工作电压从1.8V到3.6V,内部有电压稳压

器和电池监视器,工作温度-40℃到85℃。本文介绍了AT86RF212的主要特性和方框

图,以及基本应用电路图和所用的材料清单。此外还介绍了扩展特性应用电路图。

The AT86RF212 is a low-power, low-voltage 700/800/900 MHz transceiver

specially designed for the IEEE Standard 802.15.4, ZigBee, 6LoWPAN, and high

data rate ISM applications. For the sub-1 GHz bands, it supports low data

rates (20 and 40 kbit/s) of the IEEE Standard 802.15.4-2003 [2] and provides

optional data rates (100 and 250 kbit/s) using O-QPSK, according to the IEEE

Standard 802.15.4-2006 [1] and the respective IEEE P802.15.4c Draft

Amendment [3]. Furthermore, proprietary High Data Rate Modes up to 1000

kbit/s can be employed.

The AT86RF212 is a true SPI-to-antenna solution. RF-critical components

except the antenna, crystal, and de-coupling capacitors are integrated

on-chip. MAC and AES hardware accelerators improve overall system power

efficiency and timing.

The AT86RF212 single-chip RF transceiver provides a complete radio

interface between the antenna and the microcontroller. It comprises the

analog radio part, digital modulation and demodulation including time and

frequency synchronization, as well as data buffering. The number of external

components is minimized so that only the antenna, a filter (at high output

power levels), the crystal, and four bypass capacitors are required. The

bidirectional differential antenna pins are used in common for RX and TX,

i.e. no external antenna switch is needed. Control of an external power

amplifier is supported by two digital control signals (differential

operation).

The receiver path is based on a low-IF architecture. After channel

filtering and downconversion the low-IF signal is sampled and applied to the

digital signal processing part. Communication between transmitter and

receiver is based on direct sequence spread spectrum with different

modulation schemes and spreading codes. The AT86RF212 supports the IEEE

802.15.4-2006 standard mandatory BPSK modulation and optional O-QPSK

modulation in the 868.3 MHz and 915 MHz bands. In addition it supports the O-QPSK modulation defined in IEEE P802.15.4c for the Chinese 780 MHz band.

For applications not necessarily targeting IEEE compliant networks the radio transceiver supports proprietary High Data Rate Modes based on O-QPSK.

A single 128 byte TRX buffer stores receive or transmit data. The AT86RF212 features hardware supported 128 bit security operation. The standalone AES encryption/decryption engine can be accessed in parallel to all PHY operational modes. Configuration of the AT86RF212, reading, and writing of data memory as well as the AES hardware engine are controlled by the SPI interface and additional control signals.

On-chip low-dropout voltage regulators provide the analog and digital 1.8 V power supply. Control registers retain their settings in SLEEP mode when the regulators are turned off. The RX and TX signal processing paths are highly integrated and optimized for low power consumption.

AT86RF212主要特性:

Fully Integrated 700/800/900 MHz-Band Transceiver

Chinese WPAN Band from 779 to 787 MHz

European SRD Band from 863 to 870 MHz

North American ISM Band from 902 to 928 MHz

Direct Sequence Spread Spectrum with Different Modulation Schemes and Data Rates

BPSK with 20 and 40 kbit/s, compliant to IEEE 802.15.4-2006

O-QPSK with 100 and 250 kbit/s, compliant to IEEE 802.15.4-2006

O-QPSK with 250 kbit/s, compliant to IEEE P802.15.4c

O-QPSK with 200, 400, 500, and 1000 kbit/s PSDU Data Rate

Flexible Combination of Frequency Bands and Data Rates

Industry Leading Link Budget

Receiver Sensitivity up to -110 dBm

Programmable TX Output Power up to +10 dBm

Low Power Supply Voltage from 1.8 V to 3.6 V

Internal Voltage Regulators and Battery Monitor

Low Current Consumption

SLEEP = 0.2 μA

TRX_OFF = 0.4 mA

RX_ON = 9.0 mA

BUSY_TX = 18 mA at PTX = 5 dBm

Digital Interface

Registers, Frame Buffer, and AES Accessible through SPI

Clock Output with Configurable Rate

Radio Transceiver Features

Adjustable Receiver Sensitivity

Integrated TX/RX Switch, LNA, and PLL Loop Filter

Fast Settling PLL Supporting Frequency Hopping

Automatic VCO and Filter Calibration

Integrated 16 MHz Crystal Oscillator

128 byte FIFO for Transmit/Receive

IEEE 802.15.4-2006 Hardware Support

FCS Computation and Check

Clear Channel Assessment

Received Signal Strength Indicator, Energy Detection, and Link Quality Indication

MAC Hardware Accelerator

Automatic Acknowledgement and Retransmission

CSMA-CA and LBT

Automatic Frame Filtering

AES 128 bit Hardware Accelerator (ECB and CBC modes)

Extended Feature Set Hardware Support

True Random Number Generation for Security Applications

TX/RX Indication (External RF Front End Control)

Optimized for Low BoM Cost and Ease of Production

Low External Component Count: Antenna, Reference Crystal, and Bypass Capacitors

Excellent ESD Robustness

Industrial Temperature Range from -40°C to+85°C

32-pin Low-profile Lead-free Plastic QFN Package, 5.0 x 5.0 x 0.9 mm3

Compliant to IEEE 802.15.4-2003, IEEE 802.15.4-2006, IEEE P802.15.4c, ETSI EN 300 220-1, and FCC 47 CFR Section 15.247

图1.AT86RF212 方框图

图2.AT86RF212基本应用电路图

基本应用电路图中的材料清单(BOM):

图3. AT86RF212扩展特性应用电路图