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AD7890:  LC2MOS 8-Channel, 12-Bit Serial Data Acquisition System

The AD7890 is an 8-channel 12-bit data acquisition system. The part contains an input multiplexer, an on-chip track/hold amplifier, a high speed 12-bit ADC, a 2.5 V reference, and a high speed, serial interface. The part operates from a single 5 V supply and accepts an analog input range of ±10 V (AD7890-10), 0 V to 4.096 V (AD7890-4), and 0 V to 2.5 V (AD7890-2).

The multiplexer on ...More

AD7890:  LC2MOS 8-Channel, 12-Bit Serial Data Acquisition System

Product Description

The AD7890 is an 8-channel 12-bit data acquisition system. The part contains an input multiplexer, an on-chip track/hold amplifier, a high speed 12-bit ADC, a 2.5 V reference, and a high speed, serial interface. The part operates from a single 5 V supply and accepts an analog input range of ±10 V (AD7890-10), 0 V to 4.096 V (AD7890-4), and 0 V to 2.5 V (AD7890-2).

The multiplexer on the part is independently accessible. This allows the user to insert an antialiasing filter or signal conditioning, if required, between the multiplexer and the ADC. This means that one antialiasing filter can be used for all eight channels. Connection of an external capacitor allows the user to adjust the time given to the multiplexer settling to include any external delays in the filter or signal conditioning circuitry.

Output data from the AD7890 is provided via a high speed bidirectional serial interface port. The part contains an on-chip control register, allowing control of channel selection, conversion start, and power-down via the serial port. Versatile, high speed logic ensures easy interfacing to serial ports on microcontrollers and digital signal processors.

In addition to the traditional dc accuracy specifications such as linearity, full-scale, and offset errors, the AD7890 is also specified for dynamic performance parameters including harmonic distortion and signal-to-noise ratio.

Power dissipation in normal mode is low at 30 mW typical and the part can be placed in a standby (power-down) mode if it is not required to perform conversions. The AD7890 is fabricated in Analog Devices, Inc.'s Linear Compatible CMOS (LC2MOS) process, a mixed technology process that combines precision bipolar circuits with low power CMOS logic. The part is available in a 24-lead, 0.3" wide, plastic or ceramic dual-in-line package or in a 24-lead small outline package (SOIC_W).

Product Highlights

  1. Complete 12-Bit Data Acquisition System-on-a-Chip. The AD7890 is a complete monolithic ADC combining an 8-channel multiplexer, 12-bit ADC, 2.5 V reference, and a track/hold amplifier on a single chip.
  2. Separate Access to Multiplexer and ADC. The AD7890 provides access to the output of the multiplexer allowing one antialiasing filter for 8 channels—a considerable savings over the 8 antialiasing filters required if the multiplexer is internally connected to the ADC.
  3. High Speed Serial Interface. The part provides a high speed serial interface for easy connection to serial ports of microcontrollers and DSP processors.

  • Fast 12-bit ADC with 5.9 µs conversion time
  • Eight single-ended analog input channels
  • Selection of input ranges:
    ±10 V for AD7890-10
    0 V to 4.096 V for AD7890-4
    0 V to 2.5 V for AD7890-2
  • Allows separate access to multiplexer and ADC
  • On-chip track/hold amplifier
  • On-chip reference
  • High-speed, flexible, serial interface
  • Single supply, low-power operation (50 mW max)
  • Power-down mode (75 µW typ)

Functional Block Diagram for AD7890

Pricing, Packaging & Availability

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Model
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Status
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  • Pre-Release: The model has not been released to general production, but samples may be available.
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  • 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
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Sample availability may be better than production availability. Please enter samples into your cart to check sample availability.

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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.