Features and Benefits
- IQ quadrature demodulator
- Integrated fractional-N PLL and VCO
- Gain control range: 60 dB
- Input frequency range: 100 MHz to 1000 MHz
- Input P1dB: +12 dBm at 0 dB gain
- Input IP3: +22.5 dBm at 0 dB gain
- Noise figure: 11 dB at >39 dB gain, 49 dB at 0 dB gain
- Baseband 1 dB bandwidth: 250 MHz in wideband mode, 50 MHz in narrowband mode
- SPI/I2C serial interface
- Power supply: +3.3 V/350 mA
The ADRF6850 is a highly integrated broadband quadrature demodulator, frequency synthesizer, and variable gain amplifier (VGA). The device covers an operating frequency range from 100 MHz to 1000 MHz for use in both narrowband and wideband communications applications, performing quadrature demodulation from IF directly to baseband frequencies.
The ADRF6850 demodulator includes a high modulus fractional-N frequency synthesizer with integrated VCO, providing better than 1 Hz frequency resolution, and a 60 dB gain control range provided by a front-end VGA.
Control of all the on-chip registers is through a user-selected SPI interface or I2C interface. The device operates from a single power supply ranging from 3.15 V to 3.45 V.
- Broadband communications
- Cellular communications
- Satellite communications
Product Lifecycle Recommended for New Designs
This product has been released to the market. The data sheet contains all final specifications and operating conditions. For new designs, ADI recommends utilization of these products.
Evaluation Kits (1)
The ADRF6850 evaluation board (EVAL-ADRF6850EB1Z) is designed to allow the user to evaluate all aspects of the ADRF6850. The board comes with a software GUI on a CD which allows the user to write to the complete register set of the ADRF6850 through the parallel port of a PC either via an SPI or I2C interface. It has SMA connectors for the demodulator’s input RF signal (connected for single-ended operation on this board), the output baseband signals, the VGAIN input which controls the gain of the VGA as well as the +3.3V power supplies. It contains a 13.5 MHz reference clock for the reference input of the on-chip PLL and the ability to drive this input with an external reference clock if so desired. It contains a 4th order loop filter for the PLL which is optimized for best rms jitter performance with a 13.5 MHz reference clock and a charge pump current of 2.5 mA. The loop bandwidth is approximately 50 kHz with a phase margin of 55⁰. The PLL frequency and performance can be monitored using the LOMON outputs. These are open-collector outputs and need to be terminated to 3.3V using on-board 50 Ω resistors or pull-up inductors. Lock detect and MUXOUT can also be monitored. All supplies are decoupled by a parallel combination of 100 nF and 56 pF capacitors. Low frequency decoupling is provided by a 10 µF capacitor. More details of the evaluation board is contained in the ADRF6850 datasheet.
Tools & Simulations
ADIsimPLL enables the rapid and reliable evaluation of new high performance PLL products from ADI. It is the most comprehensive PLL Synthesizer design and simulation tool available today. Simulations performed include all key non-linear effects that are significant in affecting PLL performance. ADIsimPLL removes at least one iteration from the design process, thereby speeding the design- to-market.
ADIsimRF is an easy-to-use RF signal chain calculator. Cascaded gain, noise, distortion and power consumption can be calculated, plotted and exported for signal chains with up to 50 stages. ADIsimRF also includes an extensive data base of device models for ADI’s RF and mixed signal components.
ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well. "Zero defects" for shipped products is always our goal.
Sample & Buy
The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Analog Devices, Inc. sales office or authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.