آر اف (فرکانس رادیویی) و بی‌سیم آی سی‌ فرستنده‌گیرنده آر اف

Product Attributes

Introduction

The TRF6900 single-chip solution is an IC designed for low-cost FSK transceivers, intended to establish frequency-agile, half-duplex, bidirectional RF links. The device is housed in a 48-pin TQFP package and designed to provide a fully functional multi-channel FM transceiver. The chip supports linear (FM) or digital (FSK) modulation applications, operating in the new European 868 MHz band and the North American 915 MHz ISM band. The single-chip transceiver operates at a minimum supply voltage of 2.2V and is specifically designed for low power consumption. The synthesizer provides a typical channel spacing of approximately 230 Hz, enabling both narrowband and wideband applications. Due to the narrow channel spacing of the direct digital synthesizer (DDS), the DDS can be used to fine-tune TX/RX frequencies and allows the use of low-cost reference crystals.

Features

• 850 MHz to 950 MHz operation
• FM/FSK operation for transmit and receive
• 24-bit DDS with 11-bit DAC
• On-chip VCO and PLL
• On-chip reference oscillator
• Minimal required external components
• Low power consumption
• Typical output power of 4.5 dBm
• Typical output frequency resolution of 230 Hz
• Extremely fast lock time due to DDS implementation
• Two fully programmable operating modes
• 2.2 V to 3.6 V operation
• Fast RSSI
• Flexible serial interface for TI MSP430 microcontroller connectivity
• 48-pin low-profile PQFP
• The TRF6900 single-chip solution is an IC designed for use as a low-cost FSK transceiver to establish a frequency-flexible half-duplex bidirectional RF link.
• The device is suited for linear (FM) or digital (FSK) modulation applications in the new 868 MHz European band and the North American 915 MHz ISM band.
• The typical channel spacing of the synthesizer is approximately 230 Hz, enabling both narrowband and wideband applications.
• Two fully programmable operating modes (Mode 0 and Mode 1) allow extremely fast switching between two preprogrammed settings without reprogramming the device.
• Each functional block of the transceiver can be individually enabled or disabled via the serial interface.
• A new unlicensed band of 868 MHz to 870 MHz has been allocated in Europe.
• The North American unlicensed ISM (Industrial, Scientific, and Medical) band covers 902 MHz to 928 MHz (center frequency 915 MHz).
• The transmitter consists of an integrated VCO, a fully programmable DDS, and a power amplifier.
• An 8-bit FSK frequency deviation register determines the frequency deviation in FSK mode.
• Modulation itself is performed within the DDS, so no additional external components are required.
• Typical RF output power is approximately 4.5 dBm.
• The integrated receiver is designed for use as a single-conversion FSK receiver.
• It consists of an LNA, mixer, IF amplifier, limiter, FM/FSK demodulator with external LC resonant circuit, and data slicer.
• The RSSI can be used for fast carrier detection or as an OOK/ASK demodulator.
• In learning mode, during the learning sequence (0,1,0,1,0,...), the initial tolerance of the LC demodulator resonant circuit is compensated, and an external capacitor is charged to a DC voltage proportional to the average demodulated DC level.
• Using the internal data switch, demodulated OOK and FSK signals are both available at the same DATA_OUT port.
• The TRF6900 connects easily to a baseband processor such as the Texas Instruments ultra-low-power MSP430 microcontroller.
• The TRF6900 serial control registers are programmed by the MSP430, which performs baseband operations in software.
• The LNA provides a typical gain of 13 dB and a typical noise figure of 3.3 dB.
• Two operating modes are selectable: normal mode and low-gain mode.
• The RF mixer is designed to work with the on-chip VCO.
• The first IF amplifier provides a typical gain of 7 dB to compensate for losses introduced by the ceramic filter.
• The second IF amplifier/limiter consists of several differential amplifier stages with a total gain of approximately 80 dB.
• The RSSI provides a voltage at terminal 33 (RSSI_OUT) proportional to the RF limiter input level.
• The demodulator supports both analog (FM) and digital (FSK) frequency demodulation.
• The variable inductor inside the TRF6900 operates in parallel with the external resonant circuit to adjust its resonant frequency.
• In learning mode, the initial tolerance of the LC demodulator resonant circuit is compensated, and an external capacitor (connected to terminal 29, S&H_CAP) is charged to a DC voltage proportional to the average demodulated DC level.

Applications

• 868 MHz European band
• 915 MHz North American ISM band
• Short-range RF link
• Frequency-agile, half-duplex, bidirectional RF link
• Linear (FM) or digital (FSK) modulation applications