|
Maxim公司的MAX7034是全集成低功耗CMOS超外差式接收器,工作頻率300MHz 到450MHz,非常適合接收ASK數據,RF靈敏度-114dBm,工作電壓5V,內置44dB RF鏡像抑制.主要用在汽車遙控,安全系統,車庫開門器, 無線遙控門鎖,家庭自動化,遙控,無線傳感器,遙測等.本文介紹了MAX7034主要特性,方框圖,典型應用電路以及接收器參考設計電路圖,材料清單和PCB布局圖. The MAX7034 fully integrated low-power CMOS superheterodyne receiver is ideal for receiving amplitudeshift-keyed (ASK) data in the 300MHz to 450MHz frequency range (including the popular 315MHz and 433.92MHz frequencies). The receiver has an RF sensitivity of -114dBm. With few external components and a low-current power-down mode, it is ideal for cost-sensitive and power-sensitive applications typical in the automotive and consumer markets. The MAX7034 consists of a low-noise amplifier (LNA), a fully differential image-rejection mixer, an on-chip phase-locked loop (PLL) with integrated voltage-controlled oscillator (VCO), a 10.7MHz IF limiting amplifier stage with received-signal-strength indicator (RSSI), and analog baseband data-recovery circuitry. The MAX7034 is available in a 28-pin (9.7mm x 4.4mm) TSSOP package and is specified over the automotive (-40℃ to +125℃) temperature range. MAX7034主要特性: _ Optimized for 315MHz or 433.92MHz Band _ Operates from Single +5.0V Supply _ Selectable Image-Rejection Center Frequency _ Selectable x64 or x32 fLO/fXTAL Ratio _ Low (< 6.7mA) Operating Supply Current _ < 3.0μA Low-Current Power-Down Mode for Efficient Power Cycling _ 250μs Startup Time _ Built-In 44dB RF Image Rejection _ Excellent Receive Sensitivit MAX7034應用: Automotive Remote Keyless Entry Security Systems Garage Door Openers Home Automation Remote Controls Local Telemetry Wireless Sensors 
圖1. MAX7034方框圖
圖2. MAX7034典型應用電路圖 MAX7034接收器參考設計 The MAX7034 receiver reference design (RD) is a self-contained evaluation platform for exercising the product as a tube motor receiver module. This receiver (Rx) board includes a simple power supply, data interface, and an antenna connection, all in a small modular form師factor that allows the receiver to be placed inside of a tubular enclosure. The Rx board was manufactured to be usable as-is. Gerber files are available for simple cut-and-paste of the radio system design. The MAX7034 315MHz/434MHz amplitude-shift-keyed (ASK) superheterodyne receiver is configured in a near-standard form similar to the typical application circuit illustrated in the MAX7034 data sheet. The system is targeted for 433.92MHz operation and a 1kbps (NRZ) data rate. Four resistor connections are included in the design to allow flexible use of certain pins. Two connections have resistor footprints but are wired as shorts: R5 connects IR_SEL to VDD and R6 connects EN_REG to VDD. Two other connections are left open (unpopulated): R4 can connect DSP to DATAOUT for hysteresis and R7 can connect DSN to 3V3 for squelch. The module is designed to have a small footprint with minimal connections, to include a pair of pins for antenna/ground connections and a triplet of pins for ground/RX data/power connections. The board uses a 5V power supply.
圖3. MAX7034接收器參考設計A2外形圖
圖4. MAX7034接收器參考設計電路圖 Rx板材料清單:
圖5. MAX7034接收器板PCB布局圖 詳情請見: 
MAX7034.pdf
(253.38 KB)
REFD5390.pdf
(585.06 KB)
來源：網絡 |
