ADR440ARZ

Overview

The ADR440ARZ is an ultralow noise, low dropout (LDO) XFET voltage reference manufactured by Analog Devices Inc. It provides a fixed output voltage of 2.048 V with an initial accuracy of ±3 mV for the A grade and ±1 mV for the B grade. The device features a temperature coefficient of 10 ppm/°C (A grade) or 3 ppm/°C (B grade). It operates within a supply voltage range of 3 V to 18 V, requiring a minimum headroom of 500 mV. The ADR440 can source up to 10 mA and sink up to -5 mA of load current. Quiescent current is typically 3.75 mA. Noise performance is specified at 1 µV p-p from 0.1 Hz to 10 Hz.

Feature Summary

• Utilizes XFET technology to achieve exceptionally low noise levels compared to traditional buried Zener references.
• Features a dedicated TRIM pin allowing for output voltage adjustment over a 0.5% range without compromising performance.
• Operates with low supply voltage headroom of 500 mV, enabling efficient power usage in battery-powered applications.
• Provides high output drive capability with the ability to source 10 mA and sink 5 mA.

Applications

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

Procurement Notes

Verify the specific electrical grade (A or B) required for your application, as initial accuracy and temperature coefficients differ between grades. Confirm the package suffix matches your PCB design requirements; the ARZ designation indicates an 8-lead SOIC_N package. Ensure input voltage remains within the 3 V to 18 V operating range and that thermal dissipation limits are respected under maximum load conditions.

Selection Notes

Select the ADR440ARZ when ultralow noise performance is critical for signal integrity in precision measurement circuits. Choose this component if the design requires a fixed 2.048 V reference with minimal temperature drift. Consider the B grade variant if tighter initial accuracy and lower temperature coefficients are necessary. Evaluate the need for the trim function if system-level calibration is desired to offset residual errors.

Part Context

The ADR440ARZ belongs to the ADR44x series of XFET voltage references, which also includes models with different fixed output voltages such as 2.5 V, 3.0 V, 4.096 V, and 5.0 V. These devices share common architectural features including low dropout operation, high output current capability, and the use of extra implanted junction FET technology for superior noise and stability characteristics across the extended industrial temperature range.

Replacement Considerations

Direct functional substitutes within the same family include the ADR441ARZ (2.5 V), ADR443ARZ (3.0 V), ADR444ARZ (4.096 V), and ADR445ARZ (5.0 V), provided the output voltage requirement differs. For alternative technologies, consider bandgap references if noise specifications are less stringent, though XFET devices generally offer superior low-frequency noise performance.