AD7821KRZ-REEL

Overview

The AD7821KRZ-REEL is an 8-bit analog-to-digital converter featuring a built-in track-and-hold function and half-flash conversion architecture. It operates on a single +5 V supply for unipolar inputs or dual ±5 V supplies for bipolar ranges, with a maximum sampling rate of 1 MS/s and a conversion time of 660 ns. The device utilizes a parallel interface with three-state data outputs and requires no external clock. Key electrical parameters include a signal-to-noise ratio of 45 dB minimum, total unadjusted error of ±1 LSB, and power dissipation of 50 mW. It is housed in a 20-lead SOIC package.

Feature Summary

• Built-in track-and-hold function supporting input signals up to 100 kHz without external components
• Half-flash conversion technique eliminates the need for an external clock signal
• Flexible reference inputs allow for both unipolar and bipolar operation configurations
• Standard microprocessor control signals enable direct interfacing with high-speed data buses

Applications

• Digital signal processing systems requiring precise sampling intervals
• Voice recognition and echo cancellation circuits
• Adaptive filtering applications

Procurement Notes

Verify the specific suffix REEL indicates tape and reel packaging when sourcing this component. Confirm that the K version temperature range meets the operational requirements of the target environment. Ensure the ordering documentation matches the exact part number to avoid discrepancies in package type or performance specifications.

Selection Notes

Select this model for applications requiring fast conversion times and high input bandwidth without external hold circuits. Consider the parallel interface requirements and the availability of standard microprocessor control lines. Evaluate the power consumption against system constraints and verify compatibility with the desired reference voltage configuration for the specific input range needed.

Part Context

This component belongs to the AD7821 series of high-speed 8-bit ADCs from Analog Devices. It serves as an improved successor to the AD7820, offering faster conversion speeds and wider signal bandwidth. The series is designed for applications demanding high accuracy and speed in compact surface-mount packages.

Replacement Considerations

The AD7820 is a compatible predecessor within the same family, though it offers slower conversion times and narrower bandwidth. Verify pinout compatibility and timing differences when substituting.