ADR444BRZ-REEL7

Overview

The ADR444BRZ-REEL7 is an ultralow noise, low dropout (LDO) XFET voltage reference with a fixed output of 4.096 V. It features B-grade initial accuracy of ±1.6 mV (±0.04%) and a temperature coefficient of 3 ppm/°C over the −40°C to +125°C range. The device operates from an input voltage of 4.6 V to 18 V with a minimum headroom of 500 mV. It provides a quiescent current of 3.75 mA, sources up to 10 mA, and sinks up to 5 mA. Voltage noise is 1.8 µV p-p in the 0.1 Hz to 10 Hz band.

Feature Summary

• Utilizes patented XFET technology for exceptionally low noise and minimized temperature drift nonlinearity.
• Features a dedicated TRIM pin allowing output voltage adjustment within a 0.5% range without compromising performance.
• Capable of sourcing 10 mA and sinking 5 mA load currents while maintaining stability with minimal supply voltage headroom.

Applications

• Precision data acquisition systems
• High resolution data converters
• Battery-powered instrumentation
• Portable medical instruments
• Industrial process control systems

Procurement Notes

Verify the specific suffix REEL7 indicates reel packaging when ordering. Confirm that the B grade designation corresponds to the required 3 ppm/°C temperature coefficient and ±1.6 mV initial accuracy specifications. Ensure the SOIC-8 package type matches the target PCB footprint design constraints.

Selection Notes

Select this component for applications requiring high precision and ultralow noise in a compact surface-mount package. The 4.096 V output is standard for many DACs. Consider the 500 mV dropout requirement against available supply rails. The trim capability allows for system-level error correction if necessary.

Part Context

This part belongs to the ADR44x series of XFET voltage references manufactured by Analog Devices. The family includes variants with different fixed output voltages such as 2.048 V, 2.5 V, 3.0 V, and 5.0 V. All members share the same core technology, offering superior noise performance compared to traditional buried Zener references.

Replacement Considerations

Other models in the ADR44x family (ADR440, ADR441, ADR443, ADR445) are pin-compatible but offer different fixed output voltages. Verify that the 4.096 V output is suitable for the specific application before substituting with other series members.

FAQ

What is the purpose of the TRIM pin on the ADR444?

The TRIM pin allows users to adjust the output voltage over a 0.5% range to compensate for system errors or reference inaccuracies without degrading the device's temperature performance.

How does the ADR444 achieve low noise performance?

It uses XFET technology, which employs two junction field effect transistors (JFETs) with different pinch-off voltages. This method generates a reference with significantly lower noise than band gap references because the correction term requires less circuitry.