Front-end for RF saves board space
02 September 2008
An integrated RF Tx modulator and Rx analogue baseband is for 900MHz RFID readers and ISM devices.
The ADF9010 from Analog Devices is an integrated RF Tx modulator and Rx analogue baseband for use in applications that operate in the 900MHz range, including RFID readers and ISM (industrial, scientific and medical) band radio communications devices. As well as professional mobile radios, mobile phone basestations and RF-over-coax applications.
The single chip device integrates a Tx quadrature modulator with an integer-N synthesizer and on-chip low-phase-noise, VCO (voltage-controlled oscillator), claimed to maintain RF performance and lower system cost.
In an RFID application, Analog Devices reckons it can save as much as 50 per cent of the bill of materials and reduce board space by up to 70 per cent, as well as reducing design cycle time, compared to a multiple discrete component method.
The ADF9010 operates at 840MHz to 960MHz. The receive path consists of a differential I/Q baseband programmable gain amplifier and programmable low pass filter. The Rx filter is programmable from 3dB to 24dB in 3dB increments. There are four programmable modes, with auto-calibrated cut-off frequencies of 330kHz, 880kHz and 2MHz. The filter can be bypassed.
The integer-N PLL achieves phase noise of -140dBc/Hz at 1MHz offset. This output signal can be used to an external RF demodulator.
The transmit path is an integrated differential Tx direct I/Q upconverter, which converts a baseband I/Q signal to an RF carrier-based signal within the frequency range. Sideband suppression is >45dB, achieved via the VCO and the quadrature. The transmit path delivers OIP3 of 24dBm, output P1 dB of +10dBm and output noise at -158dBm/Hz.
The on-chip registers are controlled using a three-wire serial interface. The device consumes 240mA from a 3.3V supply and can be powered down when not in use.
The analogue front-end is available in a 7mm x 7mm 48lead LFCSP.
Contact Details and Archive...
Related Articles...
Most Viewed Articles...