ADR421ARZ

Overview

The ADR421ARZ is a second-generation XFET voltage reference providing a fixed 2.500 V output in an 8-lead SOIC package. It features low noise of 1.75 µV p-p (0.1 Hz to 10 Hz) and a temperature coefficient of 3 ppm/°C for the B grade. The device operates with a quiescent current of 500 µA maximum, supports up to 10 mA load current, and functions within a supply range of 4.5 V to 18 V across an extended industrial temperature range of −40°C to +125°C.

Feature Summary

• Utilizes eXtra implanted junction FET (XFET) technology to minimize nonlinearity and provide superior accuracy compared to band gap references.
• Includes a dedicated trim terminal allowing output voltage adjustment over a ±0.5% range without compromising other performance characteristics.
• Offers excellent long-term stability and low thermal hysteresis suitable for precision applications.

Applications

• Precision data acquisition systems
• High resolution converters
• Optical network control circuits

Procurement Notes

Verify the specific electrical grade required for the design, as the ADR421 series includes both A Grade and B Grade options with differing initial accuracy and temperature coefficients. Confirm that the 8-lead SOIC footprint matches the PCB layout constraints. Ensure the selected part number suffix corresponds to the desired packaging format, such as tube or reel, before finalizing procurement orders.

Selection Notes

Select the ADR421ARZ when a stable 2.500 V reference is needed with minimal low-frequency noise. The B grade offers tighter specifications for initial accuracy and temperature drift compared to the A grade. Consider the 2 V minimum input-output voltage differential requirement when designing the power supply rail to ensure proper regulation under all load conditions.

Part Context

This component belongs to the ADR42x family of ultraprecision voltage references manufactured by Analog Devices. The series includes variants with different nominal outputs, specifically the ADR420 (2.048 V), ADR423 (3.00 V), and ADR425 (5.00 V). All members share the same XFET architecture and are available in 8-lead SOIC and MSOP packages.

Replacement Considerations

Direct functional replacements within the same series include the ADR420ARZ, ADR423ARZ, and ADR425ARZ, provided the specific output voltage requirements align with the application needs. Other grades within the ADR421 family, such as the ADR421BRZ, offer higher precision but must be verified against the specific accuracy and drift specifications required.