Features and Benefits

  • 12-bit SAR ADC
    • 8 single-ended analog input channels
    • Analog input range: 0 V to 2.5 V
  • 12-bit temperature-to-digital converter
    • Temperature sensor accuracy of ±1°C typical
  • Channel sequencer operation
  • Specified for VDD of 2.8 V to 3.6 V
  • Logic voltage VDRIVE = 1.65 V to 3.6 V
  • Internal 2.5 V reference
  • See data sheet for additional features
AD7291-EP supports defense and aerospace applications (AQEC
  • Download AD7291-EP data sheet (pdf)
  • Extended industrial temperature range: −55°C to +125°C
  • Controlled manufacturing baseline
  • 1 assembly/test site
  • 1 fabrication site
  • Product change notification
  • Qualification data available upon request
  • V62/17610 DSCC Drawing Number

Product Details

The AD7291 is a 12-bit, low power, 8-channel, successive approximation analog-to-digital converter (ADC) with an internal temperature sensor.

The part operates from a single 3.3 V power supply and features an I2C-compatible interface. The part contains a 9-channel multiplexer and a track-and-hold amplifier than can handle frequencies up to 30 MHz. The device has an on-chip 2.5 V reference that can be disabled to allow the use of an external reference.

The AD7291 provides a 2-wire serial interface compatible with I2C interfaces. The I2C interface supports standard and fast I2C interface modes. The AD7291 normally remains in a partial power-down state while not converting and powers up for conversions. The conversion process can be controlled by a command mode where conversions occur across I2C write operations or an autocycle mode selected through software control.

The AD7291 includes a high accuracy band gap temperature sensor, which is monitored and digitized by the 12-bit ADC to give a resolution of 0.25°C.

The AD7291 offers a programmable sequencer, which enables the selection of a preprogrammable sequence of channels for conversion.

On-chip limit registers can be programmed with high and low limits for the conversion results; an out-of-range indicator output (ALERT) becomes active when the programmed high or low limits are violated by the conversion result. This output can be used as an interrupt.

Product Highlights

  1. Ideally suited to monitoring system variables in a variety of systems including telecommunications, process control, and industrial control.
  2. I2C-compatible serial interface. Standard and fast modes.
  3. Automatic partial power-down while not converting to maximize power efficiency.
  4. Channel sequencer operation.
  5. Integrated temperature sensor with 0.25°C resolution.
  6. Out of range indicator that can be software disabled or enabled.

Product Lifecycle icon-recommended Recommended for New Designs

This product has been released to the market. The data sheet contains all final specifications and operating conditions. For new designs, ADI recommends utilization of these products.

Evaluation Kits (8)

Product Recommendations

AD7291 Companion Parts

Recommended Input Buffer Amplifiers

  • For a precision, battery-powered, instrumentation amplifier: AD8420.
  • For low power applications: ADA4692-2.
  • For applications requiring highest precision: AD8606.
  • For high speed, low noise, low distortion: AD8022.
  • For applications requiring low cost, low temperature drift, good DC and AC precision: AD8692.

Recommended High Accuracy, Precision External References - 2.5V

  • For cost sensitive applications: AD1582, ADR391.
  • For high output current applications: ADR431.
  • For applications requiring the lowest noise performance and output trim adjust: ADR441.
  • For wide supply applications: AD780.

Design Resources

ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well.  "Zero defects" for shipped products is always our goal.

PCN-PDN Information

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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.