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AD654:  Low Cost Monolithic Voltage-to-Frequency Converter

Product Details

The AD654 is a monolithic V/F converter consisting of an input amplifier, a precision oscillator system, and a high current output stage. A single RC network is all that is required to set up any full scale (FS) frequency up to 500 kHz and any FS input voltage up to ±30 V. Linearity error is only 0.03% for a 250 kHz FS, and operation is guaranteed over an 80 dB dynamic range. The overall temperature coefficient (excluding the effects of external components) is typically ±50 ppm/°C. The AD654 operates from a single supply of 5 V to 36 V and consumes only 2.0 mA quiescent current.

The low drift (4 µV/°C typ) input amplifier allows operation directly from small signals such as thermocouples or strain gauges while offering a high (250 M(ohm)) input resistance. Unlike most V/F converters, the AD654 provides a square-wave output, and can drive up to 12 TTL loads, optocouplers, long cables, or similar loads.


  • Low Cost
  • Single or Dual Supply,
    5 V to 36 V, ±5 V to ±18 V
  • Full-Scale Frequency Up to 500 kHz
  • Minimum Number of External Components Needed
  • Versatile Input Amplifier
    - Positive or Negative Voltage Modes
    - Negative Current Mode
    - High Input Impedance, Low Drift
  • Low Power: 2.0 mA Quiescent Current
  • Low Offset: 1 mV

Functional Block Diagram for AD654


Title Content Type File Type
AD654: Low Cost Monolithic Voltage-to-Frequency Converter Data Sheet (Rev C, 07/2013) (pdf, 180 kB) Data Sheets PDF
AN-361: Ask the Applications Engineer (V/F Converters)  (pdf, 287 kB) Application Notes PDF
AN-276: Analog to Digital Conversion by Using V/F Converters  (pdf, 646 kB) Application Notes PDF
AN-278: Operation and Applications of the AD654 IC V-to-F Converter  (pdf, 3376 kB) Application Notes PDF
Single-Supply Acceleration-to-Frequency Circuits
(Analog Dialogue, Vol. 29, No. 3, 1995)
Analog Dialogue HTML
High-Frequency Signal-Contamination Analog Dialogue HTML
Ask The Applications Engineer-3
(V/F Converters)

(Analog Dialogue, 30th Anniversary Reader Bonus)
Analog Dialogue HTML
RAQs index Rarely Asked Questions HTML
What is a Voltage to Frequency Converter (VFC) and how can the be used to send analog signals over long distances without loss of accuracy? FAQs/RAQs HTML
Glossary of EE Terms Glossary HTML

Evaluation Kits & Symbols & Footprints

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.

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Price, packaging, availability

AD654 Model Options
Model Package Pins Temp.
Price*(100-499) Price*1000 pcs RoHS View PCN/ PDN Check Inventory/
AD654JN Status: Production 8 ld PDIP 8 Comm. Tube, 50 $5.00 $4.47 N  Material Info PCN Purchase
AD654JNZ Status: Production 8 ld PDIP 8 Comm. Tube, 50 $4.45 $4.00 Y  Material Info PCN Purchase
AD654JNZ/+ Status: Last Time Buy 8 ld PDIP 8 Comm. Tube, 50 $7.05 $7.05 Y  Material Info PCN/PDN Purchase
AD654JR Status: Production 8 ld SOIC 8 Comm. Tube, 98 $4.85 $4.35 N  Material Info PCN Purchase
AD654JR-REEL Status: Last Time Buy 8 ld SOIC 8 Comm. Reel, 2500 - $4.35 N  Material Info PCN/PDN Purchase
AD654JRZ Status: Production 8 ld SOIC 8 Comm. Tube, 98 $4.20 $3.76 Y  Material Info PCN Purchase
AD654JRZ-REEL Status: Production 8 ld SOIC 8 Comm. Reel, 2500 - $3.76 Y  Material Info PCN Purchase
AD654JRZ-REEL7 Status: Production 8 ld SOIC 8 Comm. Reel, 750 - $3.76 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.

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