Analog Front End for 900 MHz Band RF Applications from ADI

17th June 2008

Analog Devices

ES Admin

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Analog Devices has announced the availability of the ADF9010, a fully integrated RF Tx modulator and Rx analog baseband for applications that operate in the 900 MHz frequency range, including RFID readers, industrial, scientific and medical (ISM) band radio communications devices, professional mobile radios, cellular base stations and RF-over-coax applications. The ADF9010 integrates a high-performance Tx quadrature modulator with an integer-N synthesizer and on-chip low-phase-noise voltage-controlled oscillator (VCO), maintaining superb RF performance and lowering system cost. When used in an RFID application, for example, the combination of integration and performance featured in the ADF9010 can result in a bill-of-material savings of as much as 50 percent and board space reductions up to 70 percent, as well as a substantial reduction in design cycle time as compared to a multiple discrete component approach.

Analog Devices will showcase the ADF9010 this week at the 2008 International Microwave Symposium in Atlanta, Georgia (Booth #1743), together with other innovations from ADI’s broad RF portfolio including PLL and DDS synthesizers, clocks and timing ICs, RF amplifiers, demodulators, RF detectors and more.

The ADF9010 operates in the 840-MHz to 960-MHz frequency range, a level of performance few other parts on the market today can deliver in such a highly integrated form factor. The receive path consists of a fully differential I/Q baseband programmable gain amplifier (PGA) and programmable low-pass filter (LPF). The Rx LPF gain is programmable from 3 dB to 24 dB in 3-dB steps. The Rx LPF features four programmable modes, with auto-calibrated cutoff frequencies of 330 kHz, 880 kHz and 2 MHz. The filter can be bypassed if necessary.

In addition, the ADF9010 has a high performance integer-N PLL with fully integrated, low noise VCO, achieving LO phase noise of –140 dBc/Hz at 1 MHz offset. This LO output signal is also available to drive an external RF demodulator, such as Analog Devices’ ADL5382.

The transmit path consists of a fully integrated differential Tx direct I/Q upconverter, which converts a baseband I/Q signal to an RF carrier-based signal between 840 MHz and 960 MHz. The VCO runs at four times the LO frequency, and the excellent quadrature, achieved via the subsequent divide-by-4 stage, provides >45 dB sideband suppression. The transmit path delivers OIP3 of 24 dBm, output P1 dB of +10 dBm and output noise floor at –158 dBm/Hz.

Control of all of the on-chip registers on the ADF9010 is achieved via a simple 3-wire serial interface. The device consumes 240 mA from a 3.3-V power supply and can be powered down when not in use.