content here.
content here.

AD640:  120 MHZ, 50 DB DEMODULATING LOGARITHMIC AMPLIFIER

The AD640 is a complete monolithic logarithmic amplifier. A single AD640 provides up to 50 dB of dynamic range for frequencies from dc to 120 MHz. Two AD640s in cascade can provide up to 95 dB of dynamic range at reduced bandwidth. The AD640 uses a successive detection scheme to provide an output current proportional to the logarithm of the input voltage. It is laser calibrated to close ...More

AD640:  120 MHZ, 50 DB DEMODULATING LOGARITHMIC AMPLIFIER

Product Description

The AD640 is a complete monolithic logarithmic amplifier. A single AD640 provides up to 50 dB of dynamic range for frequencies from dc to 120 MHz. Two AD640s in cascade can provide up to 95 dB of dynamic range at reduced bandwidth. The AD640 uses a successive detection scheme to provide an output current proportional to the logarithm of the input voltage. It is laser calibrated to close tolerances and maintains high accuracy over the full military temperature range using supply voltages from ±4.5 V to ±7.5 V.

The AD640 comprises five cascaded dc coupled amplifier/limiter stages, each having a small signal voltage gain of 10 dB and a -3 dB bandwidth of 350 MHz. Each stage has an associated full-wave detector, whose output current depends on the absolute value of its input voltage. The five outputs are summed to provide the video output (when low-pass filtered) scaled at 1 mA per decade (50 µA per dB). On chip resistors can be used to convert this output current to a voltage with several convenient slope options. A balanced signal output at +50 dB (referred to input) is provided to operate AD640s in cascade.

The logarithmic response is absolutely calibrated to within ±l dB for dc or square wave inputs from ±0.75 mV to ±200 mV,with an intercept (logarithmic offset) at 1 mV dc. An integral X10 attenuator provides an alternative input range of ±7.5 mV to ±2 V dc. Scaling is also guaranteed for sinusoidal inputs.

The AD640B is specified for the industrial temperature range of -40°C to +85°C and the AD640T, available processed to MIL-STD- 883B, for the military range of -55°C to +125°C. Both are available in 20-pin side brazed ceramic DIPs or leadless chip carriers (LCC). The AD640J is specified for the commercial temperature range of 0°C to +70°C, and is available in both 20-pin plastic DIP (N) and PLCC (P) packages.

This device is now available to Standard Military Drawing (DESC) number 5962-9095501MRA and 5962-9095501M2A.

An evaluation board is available for this product and may be ordered using the following product number: AD640-EB.

Applications

  • Radar, Sonar, Ultrasonic and Audio Systems
  • Precision Instrumentation from DC to 120 MHz
  • Power Measurement with Absolute Calibration
  • Wide Range High Accuracy Signal Compression
  • Alternative to Discrete and Hybrid IF Strips
  • Replaces Several Discrete Log Amp ICs

    • RESOURCES & TOOLS

    What is your task? Try Lead the Way AdvisorTM BETA
    • Complete, Fully Calibrated Monolithic System
    • Five Stages, Each Having 10 dB Gain,
      350 MHz BW
    • Direct Coupled Fully Differential Signal Path
    • Logarithmic Slope, Intercept and AC Response are Stable Over Full Military Temperature Range
    • Dual Polarity Current Outputs Scaled
      1 mA/Decade
    • Voltage Slope Operation (1 V/Decade,
      100 mV/dB, etc.)
    • Low Power Operation (Typically 220 mW at
      ±5 V)
    • Low Cost Plastic Packages Also Available
    • Dynamic Range (dB): 50dB
    • Temp Stability (dB): ±1dB
    • Phase Accuracy (deg): n/a
    • Response Time (ns typ): 10ns
    • Voltage Supply (V): +/- 4.5 to +/- 7.5
    • Supply Current : 44mA
    • Limiter Output: Yes
    • AC Linearity (± dB): 3dB
    • Power Consumption (mW): 200mW
    • Package: 20-Lead DIP,20-Lead LCC,20-Lead PLCC

    Functional Block Diagram for AD640

    Similar Products:   

    View Interactive Product Selection Table

    Pricing, Packaging & Availability

    Print Table
    back to top

    Help

    Model
    The model number is a specific version of a generic that can be purchased or sampled.

    Status
    Status indicates the current lifecycle of the product. This can be one of 4 stages:
    • Pre-Release: The model has not been released to general production, but samples may be available.
    • Production: The model is currently being produced, and generally available for purchase and sampling.
    • Last Time Buy: The model has been scheduled for obsolescence, but may still be purchased for a limited time.
    • Obsolete: The specific part is obsolete and no longer available. Other models listed in the table may still be available (if they have a status that is not obsolete).
    Package Description
    The package for this IC (i.e. DIP, SOIC, BGA). An Evaluation Board is a board engineered to show the performance of the model, the part is included on the board.

    For detailed drawings and chemical composition please consult our  Package Site

    Pin Count
    Pin Count is the number of pins, balls, or pads on the device. Pin-out diagrams & pin function descriptions may be found in the datasheet.

    Temperature Range
    This is the acceptable operating range of the device. The various ranges specified are as follows:
    • Commercial: 0 to +70 degrees Celsius
    • Military : -55 to +125 degrees Celsius
    • Industrial: Temperature ranges may vary by model. Please consult the datasheet for more information.
    • Automotive: -40 to +125 degrees Celsius
    Price
    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.

    Production Availability
    This is the date Analog Devices, Inc. anticipates that the product will ship from the warehouse. Most orders ship within 48 hours of this date.Once an order has been placed, Analog Devices, Inc. will send an Order Acknowledgement email to confirm your delivery date. It is important to note the scheduled dock date on the order entry screen. We do take orders for items that are not in stock, so delivery may be scheduled at a future date. Also, please note the warehouse location for the product ordered. We have warehouses in the United States, Europe and Southeast Asia. Transit times from these sites may vary.
    Sample availability may be better than production availability. Please enter samples into your cart to check sample availability.

    RoHS Compliant
    Due to environmental concerns, ADI offers many of our products in lead-free versions. For more information about lead-free parts, please consult our Pb (Lead) free information page.

    View PCN
    This is the list of Product Change Notifications (PCN) published on the web for this model. Click on the link to access PCN Information.Only select pre-2009 PCN�s are available on-line. To obtain a pre-2009 PCN, contact your ADI Sales Rep. For more information on ADI's PCN process, please visit our PCN Policy Statement page

    *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.
    **Sample availability may be better than production availability. Please enter samples into your cart to check sample availability.