AD7721ARZ

Overview

The AD7721ARZ is a CMOS, 16-bit sigma-delta analog-to-digital converter manufactured by Analog Devices Inc. It operates from a single +5 V supply and accepts differential input ranges of 0 V to 2.5 V (unipolar) or ±1.25 V (bipolar). The device features an internal analog modulator that samples inputs at twice the clock frequency, eliminating the need for external sample-and-hold circuits. It supports both high-speed serial and parallel interfaces, with maximum clock frequencies of 15 MHz and 10 MHz respectively. Key performance metrics include a 468.75 kHz output word rate, 74 dB signal-to-noise ratio, and ±16 LSB integral nonlinearity in 16-bit operation. The component is housed in a 28-pin SOIC package.

Feature Summary

• Integrated dual-stage finite impulse response digital filters reduce external antialiasing requirements.
• On-chip calibration logic minimizes zero-scale and full-scale errors for improved DC accuracy.
• Single-bit DAC in the modulator architecture ensures excellent linearity and guarantees no missing codes.
• Configurable standby mode significantly reduces power consumption during idle periods.

Applications

• High-speed data acquisition systems requiring direct interfacing with microcontrollers.
• Digital signal processing front-ends utilizing the high-speed serial interface.
• Industrial measurement applications benefiting from integrated offset and gain calibration.

Procurement Notes

Verify component authenticity through authorized distributors as the part may be obsolete. Confirm package integrity and pin alignment against the 28-SOIC specification. Ensure compatibility with existing system voltage levels and clock requirements before integration.

Selection Notes

Select this component for designs requiring high sampling rates up to 468.75 kHz with 16-bit resolution. Consider the parallel interface option if lower latency or simpler digital timing is required compared to the serial mode. Verify that the external reference voltage matches the specified 2.5 V nominal requirement for optimal performance.

Part Context

The AD7721ARZ belongs to the AD7721 series of sigma-delta ADCs from Analog Devices. It is designed for applications demanding high speed and precision within a low-power CMOS framework. The 'ARZ' suffix indicates the industrial temperature range variant packaged in a lead-free SOIC format.

Replacement Considerations

Direct replacement options are limited due to the specific combination of speed and resolution. Evaluate other high-speed sigma-delta ADCs from the manufacturer's portfolio, ensuring interface compatibility and pin configuration match.