AD7892AR-2REEL7

Overview

The AD7892AR-2REEL7 is a 12-bit successive approximation analog-to-digital converter (ADC) from Analog Devices, operating from a single +5 V supply. It features an on-chip track/hold amplifier and an internal +2.5 V reference. The device supports both parallel and serial microprocessor interfaces. Designed for the AD7892-2 variant, it accepts a unipolar analog input range of 0 V to +2.5 V with a throughput rate of 500 kSPS. Typical power consumption is 60 mW in normal operation. It is housed in a 24-lead SOIC package.

Feature Summary

• Integrated signal scaling allows direct interfacing with 0 V to +2.5 V single-ended signals without external attenuation circuitry.
• Versatile interface logic enables flexible connection to microprocessors via either a standard 12-bit parallel bus or a high-speed three-wire serial port.
• On-chip track/hold amplifier ensures accurate sampling at maximum throughput rates by maintaining signal integrity during conversion cycles.

Applications

• Portable instrumentation requiring low power consumption and single-supply operation
• Industrial data acquisition systems utilizing microcontrollers with serial interfaces
• Battery-powered measurement devices needing integrated voltage referencing

Procurement Notes

Verify the specific suffix 'REEL7' indicates tape-and-reel packaging when sourcing components. Confirm that the 'A' version meets the required temperature range specifications for your application environment. Ensure compatibility with the 0 V to +2.5 V input range characteristic of the AD7892-2 variant before integration into the design.

Selection Notes

Select this component if the application requires a 12-bit resolution ADC with a unipolar input range limited to 0 V to +2.5 V. Consider the AD7892-1 or AD7892-3 variants if bipolar input ranges are necessary. Evaluate the trade-off between the 500 kSPS throughput rate and the 60 mW power dissipation against system performance requirements.

Part Context

This part belongs to the AD7892 family of LC2MOS single-supply ADCs. The AD7892 series distinguishes itself through integrated signal scaling and reference capabilities, reducing external component count. The AR-2 designation specifically identifies the commercial temperature range, SOIC package, and unipolar input configuration within this product line.

Replacement Considerations

Direct pin-compatible substitutes within the same family include the AD7892BR-2REEL7 for tighter accuracy specifications. Other variants such as the AD7892AN-2 or AD7892BN-2 offer different packaging options but maintain identical electrical characteristics for the -2 input range.

FAQ

How is the serial interface mode selected on the AD7892?

The serial interface mode is selected by tying the MODE pin (Pin 7) to a logic low state. In this mode, pins DB4/SCLK and DB3/RFS function as clock and frame synchronization inputs, while DB5/SDATA serves as the serial data output.

What is the purpose of the REF OUT/REF IN pin?

This pin provides access to the internal +2.5 V reference or allows connection to an external reference source. When using the internal reference, a decoupling capacitor should be connected to AGND. An external reference can overdrive the internal one to provide system-level reference precision.

Does the AD7892-2 variant include overvoltage protection on the analog inputs?

No, the datasheet specifies overvoltage protection only for the AD7892-1 and AD7892-3 variants. For the AD7892-2, the absolute maximum rating for analog input voltage is restricted to the supply rails (0 V to VDD).