ADR439ARM

Overview

The ADR439ARM is an ultralow noise XFET voltage reference with a nominal output of 4.5 V, manufactured by Analog Devices Inc. It operates within a supply voltage range of 6.5 V to 18 V and features a maximum temperature coefficient of 10 ppm/°C for the A grade. The device draws a quiescent current of 800 µA and provides high output source and sink currents of +30 mA and −20 mA respectively. It includes a trim terminal for ±0.5% output adjustment and is housed in an 8-lead MSOP package.

Feature Summary

• Utilizes patented XFET technology to minimize voltage change vs. temperature nonlinearity.
• Capable of sourcing up to 30 mA and sinking up to 20 mA without external components.
• Features a dedicated trim terminal allowing precise output voltage adjustment over a 0.5% range.

Applications

• Precision data acquisition systems
• High resolution data converters
• Medical instruments
• Industrial process control systems

Procurement Notes

Verify the specific grade (A or B) required for your application, as initial accuracy and temperature coefficients vary between grades. Confirm that the input voltage headroom meets the minimum requirement of 2 V above the 4.5 V output. Ensure the operating environment stays within the specified -40°C to +125°C range for guaranteed performance.

Selection Notes

Select the ADR439ARM when a stable 4.5 V reference is needed with low noise characteristics. Consider the A grade if higher initial accuracy is not critical but cost efficiency is desired. Verify that the load requirements do not exceed the 30 mA source or 20 mA sink limits. Check thermal resistance specifications if operating at high ambient temperatures or under heavy load conditions.

Part Context

This component belongs to the ADR43x series of XFET voltage references from Analog Devices. The series includes variants with different nominal output voltages such as 2.048 V, 2.5 V, 3.0 V, 4.096 V, and 5.0 V. All members share similar low-noise architecture and current capabilities, differing primarily in their fixed output voltage levels and corresponding input voltage headroom requirements.

Replacement Considerations

ADR439ARZ

FAQ

Does the ADR439ARM require an external bypass capacitor?

No external capacitor is required for stability, though a 0.1 µF capacitor can be added to improve noise suppression.

What is the purpose of the COMP pin on the ADR439ARM?

The COMP pin allows for adding an external RC network to overcompensate the internal op amp, reducing noise peaking caused by large capacitive loads.