Semtech SX1231 低功耗UHF收发方案

Semtech 公司的SX1231是低功耗高度集成的UHF收发器,能工作在很宽频率范围,包括433, 868 和915 MHz  M频段.在1.2kbps时的灵敏度优于-120dBm,具有16节FIR通路滤波器,因此有高的选择性.可编程输出功率,从-18dBm到+17dBm,增量1dB. FSK比特别率高达300kbps.主要用在自动读表, 无线传感器网络,家庭和建筑物自动化,无线告警和安全系统以及工业监视和控制.本文介绍SX1231主要特性,方框图以及应用电路和915MHz RF模块电路图与材料清单(BOM).

SX1231: Low Power Integrated UHF Transceiver The SX1231 is a highly integrated RF transceiver capable of operation over a wide frequency range, including the 433, 868 and 915 MHz license-free ISM (Industry Scientific and Medical) frequency bands. Its highly integrated architecture allows for a minimum of external components whilst maintaining maximum design flexibility. All major RF communication parameters are programmable and most of them can be dynamically set. The SX1231 offers the unique advantage of programmable narrow-band and wide-band communication modes without the need to modify external components. The SX1231 is optimized for low power consumption while offering high RF output power and channelized operation, suitable for both the European (ETSI EN 300-220-1) and the North American (FCC part 15) regulatory standards. TrueRF™ technology enables a lowcost external component count (elimination of the SAW filter) whilst still satisfying ETSI and FCC regulations.

SX1231主要特性:

High Sensitivity: down to -120 dBm at 1.2 kbps

High Selectivity: 16-tap FIR Channel Filter

Bullet-proof front end: IIP3 = -18 dBm, IIP2 = +35 dBm, 80 dB Blocking Immunity, no Image Frequency response

Low current: Rx = 16 mA, 100nA register retention

Programmable Pout: -18 to +17 dBm in 1dB steps

Constant RF performance over voltage range of chip

FSK Bit rates up to 300 kb/s

Fully integrated synthesizer with a resolution of 61 Hz

FSK, GFSK, MSK, GMSK and OOK modulations

Built-in Bit Synchronizer performing Clock Recovery

Incoming Sync Word Recognition

115 dB+ Dynamic Range RSSI

Automatic RF Sense with ultra-fast AFC

Packet engine with CRC, AES-128 encryption and 66-byte FIFO

Built-in temperature sensor and Low Battery indicator

SX1231应用:

Automated Meter Reading

Wireless Sensor Networks

Home and Building Automation

Wireless Alarm and Security Systems

Industrial Monitoring and Control


图1.SX1231简化方框图

图2.SX1231接收器方框图

图3.SX1231应用电路图

图4.SX1231 RF模块电路图

SX1231 915MHz RF模块材料清单(BOM):