Infineon 公司的SmartLEWISTM RX+TDA5225是具有增強靈敏度的多協議無線接收器.這種低功耗ASK/FSK接收器工作頻帶為300-320, 425-450,863-870 和902-928 MHz,電源電壓3.0-3.6 V或 4.5-5.5 V時符合汽車質量標準,工作溫度在-40 和+105℃之間. TDA5225集成了分辨率為10.5 Hz的21位Sigma-Delta分數N PLL合成器.主要用于汽車的遙控無鍵盤進入系統,胎壓監視,短程無線數據發送,遙控單元,無繩告警系統和遙控讀表.本文介紹了TDA5225主要特性, 功能方框圖以及包括RF部分, 單路/雙路下變換框圖, SK/FSK解調器和電源在內的部分功能方框圖, 典型應用框圖, 評估板v1.0電路圖, 元件布局圖和評估板材料清單.

SmartLEWISTM RX+TDA5225 Enhanced Sensitivity Multi-Channel Quad-Configuration Receiver with Digital Slicer

The IC is a low power ASK/FSK Receiver for the frequency bands 300-320, 425-450,863-870 and 902-928 MHz. The chip offers a very high level of integration and needs only a few external components.

The device is qualified to automotive quality standards and operates between -40 and +105℃ at supply voltage ranges of 3.0-3.6 Volts or 4.5-5.5 Volts.

The receiver is realized as a double down conversion super-heterodyne/low-IF architecture each with image rejection. A fully integrated Sigma-Delta Fractional-N PLL Synthesizer allows for high-resolution frequency generation and uses a crystal oscillator as the reference. The on-chip temperature sensor may be utilized for temperature drift compensation via the crystal oscillator.

The high performance down converter is the key element for the exceptional sensitivity performance of the device which take it close to the theoretical top-performance limits.It demodulates the received ASK or FSK data stream independently which can then be accessed via separate pins. The RSSI output signal is converted to the digital domain with an ADC. All these signals are accessible via the 4-wire SPI interface bus. Up to 4 pre-configured telegram parameters can be stored into the device offering independent pre-processing of the received data to an extent not available till now. The down converter can be also configured in single-conversion mode at moderately reduced selectivity performance but at the advantage of omitting the IF ceramic filter.

TDA5225主要特性:

? Enhanced sensitivity receiver

? Multi-band/Multi-Channel (300-320, 425-450, 863-870 and 902-928 MHz)

? One crystal frequency for all supported frequency bands
? 21-bit Sigma-Delta Fractional-N PLL synthesizer with high resolution of 10.5 Hz

? Up to 4 parallel parameter sets for autonomous scanning and receiving from different sources

? Up to 12 different frequency channels are supported with 10.5 Hz resolution each

? Ultrafast Wake-up on RSSI

? Selectable IF filter bandwidth and optional external filters possible

? Double down conversion image reject mixer

? ASK and FSK capability

? Automatic Frequency Control (AFC) for carrier frequency offset compensation

? NRZ data processing capability

? Sliced data output

? RSSI peak detectors

? Wake-up generator and polling timer unit

? Unique 32-bit serial number

? On-chip temperature sensor

? Integrated timer usable for external watch unit

? Integrated 4-wire SPI interface bus

? Supply voltage range 3.0 Volts to 3.6 Volts or 4.5 Volts to 5.5 Volts

? Operating temperature range -40 to +105℃

? ESD protection +/- 2 kV on all pins

? Package PG-TSSOP-28

TDA5225應用:

? Remote keyless entry systems

? Remote start applications

? Tire pressure monitoring

? Short range radio data transmission

? Remote control units

? Cordless alarm systems

? Remote metering