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ADF7021-N:  High Performance Narrow-Band Transceiver IC

Product Details

The ADF7021-N is a high performance, low power, narrow-band transceiver based on the ADF7021. The ADF7021-N has IF filter bandwidths of 9 kHz, 13.5 kHz, and 18.5 kHz, making it ideally suited to worldwide narrowband standards and particularly those that stipulate 12.5 kHz channel separation.

It is designed to operate in the narrow-band, license-free ISM bands and in the licensed bands with frequency ranges of 80 MHz to 650 MHz and 842 MHz to 916 MHz. The part has both Gaussian and raised cosine transmit data filtering options to improve spectral efficiency for narrow-band applications. It is suitable for circuit applications targeted at the Japanese ARIB STD-T67, the European ETSI EN 300 220, the Korean short range device regulations, the Chinese short range device regulations, and the North American FCC Part 15, Part 90, and Part 95 regulatory standards. A complete transceiver can be built using a small number of external discrete components, making the ADF7021-N very suitable for price-sensitive and area-sensitive applications.

The range of on-chip FSK modulation and data filtering options allows users greater flexibility in their choice of modulation schemes while meeting the tight spectral efficiency requirements. The ADF7021-N also supports protocols that dynamically switch among 2FSK, 3FSK, and 4FSK to maximize communica-tion range and data throughput.

The transmit section contains two voltage controlled oscillators (VCOs) and a low noise fractional-N PLL with an output resolution of <1 ppm. The ADF7021-N has a VCO using an internal LC tank (421 MHz to 458 MHz, 842 MHz to 916 MHz) and a VCO using an external inductor as part of its tank circuit (80 MHz to 650 MHz). The dual VCO design allows dual-band operation where the user can transmit and/or receive at any frequency supported by the internal inductor VCO and can also transmit and/or receive at a particular frequency band supported by the external inductor VCO.

The frequency-agile PLL allows the ADF7021-N to be used in frequency-hopping, spread spectrum (FHSS) systems. Both VCOs operate at twice the fundamental frequency to reduce spurious emissions and frequency pulling problems.

The transmitter output power is programmable in 63 steps from −16 dBm to +13 dBm and has an automatic power ramp control to prevent spectral splatter and help meet regulatory standards. The transceiver RF frequency, channel spacing, and modulation are programmable using a simple 3-wire interface. The device operates with a power supply range of 2.3 V to 3.6 V and can be powered down when not in use.

A low IF architecture is used in the receiver (100 kHz), which minimizes power consumption and the external component count yet avoids dc offset and flicker noise at low frequencies. The IF filter has programmable bandwidths of 9 kHz, 13.5 kHz, and 18.5 kHz. The ADF7021-N supports a wide variety of pro-grammable features including Rx linearity, sensitivity, and IF bandwidth, allowing the user to trade off receiver sensitivity and selectivity against current consumption, depending on the application. The receiver also features a patent-pending automatic frequency control (AFC) loop with programmable pull-in range that allows the PLL to track out the frequency error in the incoming signal.

The receiver achieves an image rejection performance of 56 dB using a patent-pending IR calibration scheme that does not require the use of an external RF source.

An on-chip ADC provides readback of the integrated tempera-ture sensor, external analog input, battery voltage, and RSSI signal, which provides savings on an ADC in some applications. The temperature sensor is accurate to ±10°C over the full oper-ating temperature range of −40°C to +85°C. This accuracy can be improved by performing a 1-point calibration at room temperature and storing the result in memory.


  • Chinese data sheet available
  • Low power, narrow-band transceiver
  • Frequency bands using dual VCO
    80 MHz to 650 MHz

    842 MHz to 916 MHz
  • Programmable IF filter bandwidths of 9 kHz, 13.5 kHz, and 18.5 kHz
  • Modulation schemes: 2FSK, 3FSK, 4FSK, MSK
  • Spectral shaping: Gaussian and raised cosine filtering
  • Fully automatic frequency control loop (AFC)
  • On-chip, 7-bit ADC and temperature sensor
  • On-chip VCO and fractional-N PLL
  • Data rates supported: 0.05 kbps to 24 kbps
  • 2.3 V to 3.6 V power supply
  • Programmable output power
    −16 dBm to +13 dBm in 63 steps
  • Automatic power amplifier (PA) ramp control
  • Receiver sensitivity
    −130 dBm at 100 bps, 2FSK

    −122 dBm at 1 kbps, 2FSK
  • Patent pending, on-chip image rejection calibration
  • Digital received signal strength indication (RSSI)
  • Integrated Tx/Rx switch
  • 0.1 μA leakage current in power-down mode

Functional Block Diagram for ADF7021-N

Silicon Anomaly Information and 3rd party developers information

ADF7021-N Silicon Anomaly Sheet Available (pdf, 66 kB) This anomaly list describes the known bugs, anomalies, and workarounds for the ADF7021-N transceiver.

ADF70xx Third Party Developers
There is a growing list of companies developing a wide range of solutions that support ADI’s ADF70xx products. View the list and learn more about becoming a third party developer.


Title Content Type File Type
ADF7021-N: High Performance Narrow-Band Transceiver IC Data Sheet (Rev A, 10/2014) (pdf, 2492 kB) Data Sheets PDF
AN-1285: ADF7021-N Radio Performance for Wireless Meter-Bus (WM-Bus), Mode N  (pdf, 188 kB) Application Notes PDF
AN-1258: Image Rejection Calibration on the ADF7021, ADF7021-N, and ADF7021-V  (pdf, 398 kB) Application Notes PDF
AN-1182: Understanding and Optimizing the AFC Loop on the ADF7021 for Minimum Preamble  (pdf, 224 kB) Application Notes PDF
AN-771: ADSP-BF533 EZ-KIT Lite and ADF70xx Interface  (pdf, 201 kB) Application Notes PDF
AN-859: RF Port Impedance Data, Matching, and External Component Selection for the ADF7020-1, ADF7021, and ADF7021-N  (pdf, 333 kB) Application Notes PDF
AN-0987: Designing a Wireless Transceiver System to Meet the Wireless M-Bus Standard  (pdf, 140 kB) Application Notes PDF
AN-915: CDR Operation for ADF7020, ADF7020-1, ADF7021, and ADF7025  (pdf, 439 kB) Application Notes PDF
AN-772: A Design and Manufacturing Guide for the Lead Frame Chip Scale Package (LFCSP)  (pdf, 439 kB) Application Notes PDF
AN-852: Using the Test DAC on the ADF702x to Implement Functions Such as Analog FM DEMOD, SNR Measurement, FEC Decoding, and PSK/4FSK Demodulation  (pdf, 259 kB) Application Notes PDF
Wireless Technologies for Smart Meters: Focus on Water Metering  (pdf, 493 kB) Technical Articles PDF
RF Meets Power Lines: Designing Intelligent Smart Grid Systems that Promote Energy Efficiency
RF DesignLine, March 2010
Technical Articles HTML
The Use of Short Range Wireless in a Multi-Metering System  (pdf, 220 kB)
One of the more evident trends at the recent Metering Europe 2006 event in Copenhagen was that both meter manufacturers and utility companies are placing an increased emphasis on the use of communication networks to create added value for their systems and also to leverage from infrastructure investment already in place.
(Metering International, December, 2006)
Technical Articles PDF
Understand Wireless Short-Range Devices for Global License-Free Systems
Short-range devices (SRD) are radio transmitters that communicate unidirectionally or bidirectionally with little capability of interfering with other radio equipment. They provide many different services, including home automation, wireless alarms, and remote keyless entry.
(RF DesignLine, March 07, 2007)
Technical Articles HTML
Wireless Short Range Devices and Narrowband Communications
The term “Short Range Device” (SRD) covers radio transmitters which provide either unidirectional or bi-directional communication and which have a low capability of causing interference to other radio equipment.
(Microwave Product Digest, July, 2007)
Technical Articles HTML
Design, Simulate, and Document Proprietary Wireless Systems
The broad acceptance of standards developed for short range wireless connectivity has been one of the notable features of the semiconductor market in the past few years. The available wireless standards are not always the best fit for the application’s requirements, however.
(Analog Dialogue, Volume 42, Number 4 2008)
Technical Articles HTML
Smart Metering Technology Promotes Energy Efficiency for a Greener World
The metering of electric power coming into the home is going electronic, replacing the long-established electromechanical power-line meter (from the 1890s) with all-electronic smart meters.
(RF DesignLine, July 27, 2009)
Technical Articles HTML
Low Power, Low Cost, Wireless ECG Holter Monitor Technical Articles HTML
Emerging Energy Applications Solutions Bulletin, Volume 10, Issue 4  (pdf, 1496 kB) Solutions Bulletins PDF
RF Source Booklet  (PDF, 4353 kB)
RF IC Product Overview - Version P (02/2014)
Overview PDF
RF Transceivers for Short Range Devices  (pdf, 2819 kB)
The ADF7000 series of transmitter and transceiver ICs provides high performance, robust, short range wireless connections.
Overview PDF
RAQs index Rarely Asked Questions HTML
Glossary of EE Terms Glossary HTML

Design Tools,Models,Drivers & Software

Title Content Type File Type
ADIsimSRD Design Studio
Analog Devices ADIsimSRD Design Studio is a very powerful tool allowing real-time simulation and optimization of many of the parameters in a typical wireless system using the ADF7xxx family of transceivers and transmitters.
ADIsim Design/Simulation Tools HTML
RF Design Tools ADIsim Design/Simulation Tools HTML
ADF70xx Evaluation Software  (zip, 25403 kB)
The most up-to-date ADF70xx software download is bundled with all documentation, including schematics, for the ADF70xx family of transceivers. Layout can be found in the gerber files under the documentation tab.
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.

SampleSample & Buy

Price, packaging, availability

ADF7021-N Model Options
Model Package Pins Temp.
Price*(100-499) Price*1000 pcs RoHS View PCN/ PDN Check Inventory/
ADF7021-NBCPZ Status: Production 48 ld LFCSP (7x7mm w_4.1mm EP) 48 Ind Tray, 260 $2.32 $1.99 Y  Material Info PCN Purchase Sample
ADF7021-NBCPZ-RL Status: Production 48 ld LFCSP (7x7mm w_4.1mm EP) 48 Ind Reel, 2500 - $1.99 Y  Material Info PCN Purchase
ADF7021-NBCPZ-RL7 Status: Production 48 ld LFCSP (7x7mm w_4.1mm EP) 48 Ind Reel, 750 - $1.99 Y  Material Info PCN Purchase
Price Table Help

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.

ADF7021-N Evaluation Boards
Model Description Price RoHS View PCN/ PDN Check Inventory/
EVAL-ADF70XXMBZ2 Status: Production Mother Board $151.80 Yes -
EVAL-ADF7021-NDBEZ Status: Production Daughter Board (421 MHz - 440 MHz, setup for external inductor VCO) $50.00 Yes -
EVAL-ADF7021-NDBIZ Status: Production Daughter Board (421 MHz - 458 MHz, setup for internal inductor VCO) $50.00 Yes -
EVAL-ADF7021-NDBZ2 Status: Production Daughter Board (862 MHz - 870 MHz) $50.00 Yes -
EVAL-ADF7021-NDBZ5 Status: Production Daughter Board (80 MHz to 650 MHz, RF match/loop filter not inserted) $50.00 Yes -
EVAL-ADF7021-NDB9Z Status: Production Daughter Board (169 MHz) $50.60 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.

Check Inventory & Purchase

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