Features and Benefits
- 12-Bit ADC with Fast Conversion Time: 2 µs
- Eight Single-Ended Analog Input Channels
- Specified for VDD of 2.7 V to 5.5 V
- Low Power Consumption
- Fast Throughput Rate: - 188 kSPS
- Sequencer Operation
- Automatic Cycle Mode
- I2C® Compatible Serial Interface
- I2C® Interface supports:
Standard, Fast, and High-Speed Modes
- Out of Range Indicator
- Pin-Selectable Addressing via AS
- Automatic Shutdown Mode: - 1 µA max
The AD7997 / AD7998 are 8-channel, 10- and 12-bit, low power, successive approximation ADCs with an I2C-compatible interface. The parts operate from a single 2.7 V to 5.5 V power supply and feature a 2 µs conversion time. The parts contain an 8-channel multiplexer and track-and-hold amplifier that can handle input frequencies up to 11 MHz.
The AD7997 / AD7998 provide a 2-wire serial interface that is compatible with I2C interfaces. Each part comes in two versions, AD7997-0 / AD7998-0 and AD7997-1 / AD7998-1, and each version allows at least two different I2C addresses. The I2C interface on the AD7997-0/AD7998-0 supports standard and fast I2C interface modes. The I2C interface on the AD7997-1 / AD7998-1 supports standard, fast, and high speed I2C interface modes.
The AD7997 / AD7998 normally remain in a shutdown state while not converting, and power up only for conversions. The conversion process can be controlled using the CONVST pin, by a command mode where conversions occur across I2C write operations or an automatic conversion interval mode selected through software control.
The AD7997 / AD7998 require an external reference that should be applied to the REFIN pin and can be in the range of 1.2 V to VDD. This allows the widest dynamic input range to the ADC.
On-chip limit registers can be programmed with high and low limits for the conversion result, and an open-drain, 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.
- 2 µs conversion time with low power consumption.
- I2C-compatible serial interface with pin-selectable addresses. Two AD7997/AD7998 versions allow five AD7997/AD7998 devices to be connected to the same serial bus.
- The parts feature automatic shutdown while not converting to maximize power efficiency. Current consumption is 1 µA max when in shutdown mode at 3V.
- Reference can be driven up to the power supply.
- Out-of-range indicator that can be software disabled or enabled.
- One-shot and automatic conversion rates.
- Registers store minimum and maximum conversion results.
Product Lifecycle Production
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.
Evaluation Kits (1)
The EVAL-AD7998EBZ is a fully featured evaluation Board for the AD7998. 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. This software includes the technical note describing the operation and set up of the evaluation board.
Please note: This Evaluation software does not run on Windows 8 or Windows 10 (USB driver is non-compliant with OS >Windows 7).
Software & Systems Requirements
AD7998 Companion Parts
Recommended External References - 2.5V
- For wide supply applications: AD780, ADR03, AD780.
- For cost sensitive applications: AD1582, ADR381, ADR391.
- For the reference buffer amplifier: AD8605, AD8605.
- For low noise, high output current applications: ADR431.
- For applications requiring 2.048V to 4.096V: REF191.
- For applications requiring best accuracy, low noise, low drift: ADR421, AD780, AD780.
Recommended Input Buffer Amplifiers
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.
Sample & Buy
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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