Maxim 公司的MAX7032是基于晶振的分數N的收發器,能在300MHz－450MHz內發送和接收ASK/OOK 或多或FSK數據,數據速率高達33kbps (Manchester編碼)或66kbps (NRZ編碼).單電源+2.1V － +3.6V 或+4.5V - +5.5V,典型的RF靈敏度: ASK為－114dBm,FSK 為－110dBm.主要用在工業控制,家庭自動化,遙感技術,車庫門禁,本地遙測系統,雙向無鍵盤輸入,煙霧報警和遙控等.本文介紹了MAX7032主要特性,方框圖,典型應用電路及其材料清單,以及無線自動讀表參考設計MTR部分電路圖和RDR部分電路圖與相應的材料清單,PCB布局圖.

The MAX7032 crystal-based, fractional-N transceiver is designed to transmit and receive ASK/OOK or FSK data in the 300MHz to 450MHz frequency range with data rates up to 33kbps (Manchester encoded) or 66kbps (NRZ encoded). This device generates a typical output power of +10dBm into a 50Ω load, and exhibits typical sensitivities of -114dBm for ASK data and -110dBm for FSK data. The MAX7032 features separate transmit and receive pins (PAOUT and LNAIN) and provides an internal RF switch that can be used to connect the transmit and receive pins to a common antenna.

The MAX7032 transmit frequency is generated by a 16-bit, fractional-N, phase-locked loop (PLL), while the receiver’s local oscillator (LO) is generated by an integer-N PLL. This hybrid architecture eliminates the need for separate transmit and receive crystal reference oscillators because the fractional-N PLL allows the transmit frequency to be set within 2kHz of the receive frequency. The 12-bit resolution of the fractional-N PLL allows frequency multiplication of the crystal frequency in steps of fXTAL/4096. Retaining the fixed-N PLL for the receiver avoids the higher current drain requirements of a fractional-N PLL and keeps the receiver current drain as low as possible.

The fractional-N architecture of the MAX7032 transmit PLL allows the transmit FSK signal to be programmed for exact frequency deviations, and completely eliminates the problems associated with oscillator-pulling FSK signal generation. All frequency-generation components are integrated on-chip, and only a crystal, a 10.7MHz IF filter, and a few discrete components are required to implement a complete antenna/digital data solution.

The MAX7032 is available in a small 5mm x 5mm, 32-pin,thin QFN package, and is specified to operate in the automotive -40°C to +125°C temperature range.

MAX7032主要特性:

♦ +2.1V to +3.6V or +4.5V to +5.5V Single-Supply Operation

♦ Single Crystal Transceiver

♦ User-Adjustable 300MHz to 450MHz Carrier Frequency

♦ ASK/OOK and FSK Modulation

♦ User-Adjustable FSK Frequency Deviation Through Fractional-N PLL Register

♦ Agile Transmitter Frequency Synthesizer with fXTAL/4096 Carrier-Frequency Spacing

♦ +10dBm Output Power into 50Ω Load

♦ Integrated TX/RX Switch

♦ Integrated Transmit and Receive PLL, VCO, and Loop Filter

♦ > 45dB Image Rejection

♦ Typical RF Sensitivity*

ASK: -114dBm

FSK: -110dBm

♦ Selectable IF Bandwidth with External Filter

♦ RSSI Output with High Dynamic Range

♦ Autopolling Low-Power Management

♦ < 12.5mA Transmit-Mode Current

♦ < 6.7mA Receive-Mode Current

♦ < 23.5μA Polling-Mode Current

♦ < 800nA Shutdown Current

♦ Fast-On Startup Feature, < 250μs

♦ Small 32-Pin, Thin QFN Package

MAX7032應用:

2-Way Remote Keyless Entry

Security Systems

Home Automation

Remote Controls

Remote Sensing

Smoke Alarms

Garage Door Openers

Local Telemetry Systems

圖1.MAX7032方框圖

圖2.MAX7032典型應用電路圖
圖2典型應用電路材料清單(BOM):


圖3.MTR部分電路圖(1)

圖4.MTR部分電路圖(2)

圖5.MTR部分電路圖(3)

圖6.MTR部分電路圖(4)
MTR部分材料清單:


圖7.RDR部分電路圖(1)

圖8.RDR部分電路圖(2)


圖9.RDR部分電路圖(3)

圖10.RDR部分電路圖(4)

RDR部分材料清單:




圖11.無線自動讀表參考設計PCB布局圖
詳情請見:
http://datasheets.maxim-ic.com/en/ds/MAX7032.pdf
和
http://pdfserv.maxim-ic.com/en/an/REFD5391.pdf