ADR444BRZ

Overview

The ADR444BRZ is a precision voltage reference from Analog Devices, utilizing XFET technology to deliver ultralow noise and high accuracy. It provides a fixed output of 4.096 V with an initial accuracy of ±1.6 mV (±0.04%) and a temperature coefficient of 3 ppm/°C. The device operates within a supply voltage range of 4.6 V to 18 V, requiring a minimum headroom of 500 mV. It features a quiescent current of 3.75 mA, sourcing up to 10 mA and sinking up to -5 mA. Noise performance is specified at 1.8 µV p-p in the 0.1 Hz to 10 Hz band. It is housed in an 8-lead SOIC package and rated for operation between -40°C and +125°C.

Feature Summary

• XFET technology minimizes voltage change vs. temperature nonlinearity for superior stability.
• Capable of sourcing 10 mA and sinking -5 mA output current.
• Includes a TRIM pin for adjusting output voltage over a 0.5% range without compromising performance.

Applications

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

Procurement Notes

Verify the specific ordering suffix against the manufacturer's official documentation to ensure correct packaging and grade specifications. Confirm that the input voltage requirements align with the minimum headroom constraints defined in the datasheet. Ensure compliance with RoHS directives as indicated in the product specifications before finalizing procurement orders.

Selection Notes

Select this component when low noise and high precision are critical for signal integrity. The B-grade specification ensures tight tolerance and drift characteristics suitable for demanding measurement applications. Consider the thermal resistance and power dissipation limits if operating near maximum load currents or elevated ambient temperatures.

Part Context

This part belongs to the ADR44x series of ultralow noise LDO XFET voltage references. 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 similar architectural benefits, including low dropout operation and high ripple rejection ratios, designed for high-end data acquisition and optical network applications.

Replacement Considerations

Other models within the ADR440/ADR441/ADR443/ADR445 series may serve as functional substitutes if the required output voltage differs. Verify pin compatibility and electrical specifications, particularly noise levels and temperature coefficients, before implementing any cross-model replacements.

FAQ

How does the XFET technology improve performance compared to traditional references?

XFET technology utilizes extra implanted junction FETs to minimize voltage change versus temperature nonlinearity, resulting in lower noise and better thermal stability than buried Zener references.

What is the purpose of the TRIM pin on the ADR444BRZ?

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 overall performance.