4-Channel, 12-Bit ADC with I2C Compatible Interface in 8-Lead SOT-23
The AD7991/AD7995/AD7999 are 12-/10-/8-bit, low power, successive approximation ADCs with an I2C®-compatible interface. Each part operates from a single 2.7 V to 5.5 V power supply and features a 1 μs conversion time. The track-and-hold amplifier allows each part to handle input frequencies of up to 14 MHz, and a multiplexer allows taking samples from four channels.
Each AD7991/AD7995/AD7999 provides a 2-wire serial interface compatible with I2C interfaces. The AD7991 and AD7995 come in two versions and each version has an individual I2C address. This allows two of the same devices to be connected to the same I2C bus. Both versions support standard, fast, and high speed I2C interface modes. The AD7999 comes in one version.
The AD7991/AD7995/AD7999 normally remain in a shutdown state, powering up only for conversions. The conversion process is controlled by a command mode, during which each I2C read operation initiates a conversion and returns the result over the I2C bus.
When four channels are used as analog inputs, the reference for the part is taken from VDD; this allows the widest dynamic input range to the ADC. Therefore, the analog input range to the ADC is 0 V to VDD. An external reference, applied through the VIN3/VREF input, can also be used with this part.
- Four single-ended analog input channels, or three single-ended analog input channels and one reference input channel.
- I2C-compatible serial interface. Standard, fast, and high speed modes.
- Automatic shutdown.
- Reference derived from the power supply or external reference.
- 8-lead SOT-23 package.
- System monitoring
- Battery-powered systems
- Data acquisition
- Medical instruments
At least one model within this product family is in production and available for purchase. The product is appropriate for new designs but newer alternatives may exist.
The EVAL-AD7991EBZ is a fully featured evaluation board for the AD7991. The evaluation board can be operated in complete standalone mode or connected to a PC via a standard USB interface. When operated with a PC, software is provided enabling the user to perform detailed analysis of the ADC's performance.
Please note: This Evaluation software does not run on Windows 8 or Windows 10 (USB driver is non-compliant with OS >Windows 7).
Recommended External References - 2.5V
- For the reference buffer amplifier , we recommend the AD8605 or the AD8605 .
- For low noise, high output current applications , we recommend the ADR431 .
- For applications requiring best accuracy, low noise, low drift , we recommend the ADR421, AD780 or the AD780 .
- For wide supply applications , we recommend the AD780, ADR03 or the AD780 .
- For cost sensitive applications , we recommend the AD1582, ADR381 or the ADR391 .
- For applications requiring 2.048V to 4.096V , we recommend the REF191 .
Recommended Input Buffer Amplifiers
- For low distortion, low noise, dual supplies , we recommend the AD8599 .
- For single supply, high speed, low power , we recommend the AD8031 or the AD8032 .
- For precision, high speed, low cost , we recommend the AD8604 .
- For precision, low noise, single supply , we recommend the AD8605 or the AD8605 .
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.
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.