AD7721AR

Overview

The AD7721AR 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 signals ranging from 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 in serial mode, 16-bit resolution with no missing codes, and ±16 LSB integral nonlinearity. The component is housed in a 28-lead SOIC package and functions within an industrial temperature range of -40°C to +85°C.

Feature Summary

• Integrates two cascaded finite impulse response digital filters to reduce external antialiasing requirements.
• Includes on-chip calibration logic to minimize zero-scale and full-scale errors.
• Features a low-power standby mode reducing consumption to 100 μW.
• Provides flexible interfacing through selectable serial or parallel data ports.

Applications

• High-speed data acquisition systems requiring direct microcontroller interfacing.
• Industrial process control applications utilizing differential signal inputs.
• Digital signal processing front ends requiring linear phase characteristics.

Procurement Notes

Verify component authenticity through official manufacturer channels or authorized distributors. Confirm the specific revision level matches design requirements. Ensure proper electrostatic discharge handling protocols are followed during storage and installation. Check for lead-free compliance status if required by environmental regulations.

Selection Notes

Select this component when a 16-bit resolution with high sampling rates is required. Consider the serial interface for simplified wiring or parallel mode for higher throughput. Ensure the system power supply maintains strict voltage tolerances. Verify that the external reference voltage meets the specified input current requirements.

Part Context

The AD7721AR belongs to the AD7721 family of sigma-delta converters. It shares architectural similarities with other low-power ADCs but distinguishes itself through its dual-mode interface capability and high-speed serial operation. The 'AR' suffix indicates the 28-lead Small Outline IC package variant designed for surface mount applications.

Replacement Considerations

The AD7721AR is obsolete. The AD7721ARZ is confirmed as a direct replacement offering identical functionality and pinout compatibility.