ADRF6820:  695 MHz to 2700 MHz Quadrature Demodulator with Integrated Fractional-N PLL and VCO

Product Details

Product Status:Recommended for New Designs

The ADRF6820 is a highly integrated demodulator and synthesizer ideally suited for next generation communication systems. The feature rich device consists of a high linearity broadband I/Q demodulator, an integrated fractional-N phase-locked loop (PLL), and a low phase noise multicore, voltage controlled oscillator (VCO). The ADRF6820 also integrates a 2:1 RF switch, an on-chip tunable RF balun, a programmable RF attenuator, and two low dropout (LDO) regulators. This highly integrated device fits within a small 6 mm × 6 mm footprint.

The high isolation 2:1 RF switch and on-chip tunable RF balun enable the ADRF6820 to support two single-ended, 50 Ω terminated RF inputs. A programmable attenuator ensures an optimal differential RF input level to the high linearity demodulator core. The integrated attenuator offers an attenuation range of 0 dB to 15 dB with a step size of 1 dB.

The ADRF6820 offers two alternatives for generating the differential local oscillator (LO) input signal: externally via a high frequency, low phase noise LO signal or internally via the on-chip fractional-N synthesizer. The integrated synthesizer enables continuous LO coverage from 356.25 MHz to 2850 MHz. The PLL reference input can support a wide frequency range because the divide or multiplication blocks can increase or decrease the reference frequency to the desired value before it is passed to the phase frequency detector (PFD).

When selected, the output of the internal fractional-N synthesizer is applied to a divide-by-2 quadrature phase splitter. From the external LO path, a 1× LO signal can be applied to the built-in polyphase filter, or a 2× LO signal can be used with the divide-by-2 quadrature phase splitter to generate the quadrature LO inputs to the mixers.

The ADRF6820 is fabricated using an advanced silicon-germanium BiCMOS process. It is available in a 40-lead, RoHS-compliant, 6 mm × 6 mm LFCSP package with an exposed paddle. Performance is specified over the −40°C to +85°C temperature range.


  • Cellular W-CDMA/GSM/LTE
  • Digital predistortion (DPD) receivers
  • Microwave point-to-point radios


  • I/Q demodulator with integrated fractional-N PLL
  • RF input frequency range: 695 MHz to 2700 MHz
  • Internal LO frequency range: 356.25 MHz to 2850 MHz
  • Input P1dB: 14.5 dBm at 1900 MHz RF
  • Input IP3: 35 dBm at 1900 MHz RF
  • Programmable HD3/IP3 trim
  • Single pole, double throw (SPDT) RF input switch
  • RF digital step attenuation range: 0 dB to 15 dB
  • Integrated RF tunable balun for single-ended 50 Ω input
  • Multicore integrated VCO
  • Demodulated 1 dB bandwidth: 600 MHz
  • 4 selectable baseband gain and bandwidth modes
  • Digital programmable LO phase offset and dc nulling
  • Programmable via 3-wire serial port interface (SPI)
  • 40-lead, 6 mm × 6 mm LFCSP

Functional Block Diagram for ADRF6820

Design Tools,Models,Drivers & Software

Title Content Type File Type
ADRF6820 S-Parameters  (zip, 2413 kB) S-Parameters ZIP
ADRF6820 Evaluation Board Software  (zip, 1701 kB) Evaluation Software ZIP

Evaluation Kits & Symbols & Footprints

Evaluation Boards & KitsView the Evaluation Boards and Kits page for documentation and purchasing

Symbols and Footprints— Analog Devices offers Symbols & Footprints which are compatible with a large set of today’s CAD systems for broader and easier support.

Product Recommendations & Reference Designs

Companion Products

Suggested Companion Products

Recommended Amplifiers for the ADRF6820
  • For DC couple-able dual 16 dB fixed gain, we recommend ADL5566.
  • For dual -11.5 dB to +20 dB digitally controlled VGA with 50 dBm OIP3, we recommend ADL5202.
Recommended ADCs for the ADRF6620
  • For 14-bit, 170 MSPS / 250 MSPS, JESD204B, dual analog to digital converter, we recommend AD9250.
  • For 14-bit, 80 MSPS / 155 MSPS, 1.8 V serial output, analog to digital converter, we recommend AD9641.
  • For 12-bit, 170 MSPS / 210 / 250 MSPS, 1.8 V LVDS output, analog to digital converter, we recommend AD9634.
  • For 12-bit, 370 MSPS / 500 MSPS, 1.8 V LVDS output, analog to digital converter, we recommend AD9434.
Recommended Power Solutions
  • For selecting voltage regulator products, use ADIsimPower.

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Price, packaging, availability

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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.

ADRF6820 Evaluation Board
Model Description Price RoHS View PCN/ PDN Check Inventory/
ADRF6820-EVALZ Status: Production Evaluation Board $200.00 Yes -

Pricing displayed is based on 1-piece. The USA list pricing shown is for budgetary use only, shown in United States dollars (FOB USA per unit), and is subject to change. International prices may vary due to local duties, taxes, fees and exchange rates.

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