ADR421ARM

Overview

The ADR421ARMZ is a second-generation XFET voltage reference providing a fixed 2.500 V output in an 8-lead MSOP package. It features B Grade initial accuracy of ±0.04% and temperature coefficients of 3 ppm/°C or 10 ppm/°C. The device operates from 4.5 V to 18 V with a maximum quiescent current of 500 µA and delivers up to 10 mA load current. Key electrical parameters include 1.75 µV p-p noise (0.1 Hz to 10 Hz), 50 ppm long-term stability, and operation across -40°C to +125°C.

Feature Summary

• Utilizes patented eXtra implanted junction FET (XFET) technology for superior thermal hysteresis and low noise compared to band gap references.
• Includes a dedicated TRIM terminal allowing output voltage adjustment over a ±0.5% range without compromising temperature coefficient performance.
• Offers high output drive capability of 10 mA while maintaining low supply current consumption.

Applications

• Precision data acquisition systems
• High resolution analog-to-digital converters
• Portable medical instruments

Procurement Notes

Verify the specific suffix against official documentation to confirm package type and grade. Confirm availability status as distribution channels may indicate limited stock. Ensure the ordering code matches the required initial accuracy and temperature coefficient specifications before finalizing procurement.

Selection Notes

Select this component when low noise and high precision are critical for signal integrity. The XFET architecture provides better thermal stability than standard band gap references. Consider the trim pin utility if system-level calibration is required to compensate for external circuit errors.

Part Context

The ADR421ARMZ belongs to the ADR42x series of ultraprecision voltage references manufactured by Analog Devices. This family includes variants with different nominal output voltages such as 2.048 V, 3.00 V, and 5.00 V, all sharing the same underlying XFET technology and package options.

Replacement Considerations

ADR421BRZ

FAQ

Does the ADR421 require an output capacitor for stability?

No, the ADR421 does not need output capacitors for stability under any load condition, though a small capacitor can be used for noise filtering.

What is the function of Pin 5 on the ADR421?

Pin 5 is the TRIM terminal, which allows the user to adjust the output voltage over a ±0.5% range without affecting the temperature coefficient.