ADR391AUJZ-R2

Overview

The ADR391AUJZ-R2 is a micropower, low noise precision voltage reference manufactured by Analog Devices Inc. It provides a fixed output voltage of 2.5 V with an initial accuracy of ±0.24% and a temperature coefficient of 25 ppm/°C. The device operates within a supply voltage range of 2.8 V to 15 V and supports a maximum output current of 5 mA. It features ultralow output noise of 5 μV p-p from 0.1 Hz to 10 Hz and includes a shutdown mode that reduces supply current to 3 μA maximum. The component is housed in a compact TSOT-23-5 package and functions reliably across a wide operating temperature range of -40°C to +125°C.

Feature Summary

• Integrated shutdown pin for power management
• Patented curvature correction for stability
• Capacitor-free design for board space reduction

Applications

• Battery-powered instrumentation
• Portable medical instrumentation
• Data acquisition systems
• Industrial process controls
• Automotive applications

Procurement Notes

Verify the specific grade suffix (A or B) against project requirements, as the AUJZ designation corresponds to the A grade specifications. Confirm the R2 suffix indicates reel packaging compatible with automated assembly processes. Ensure the ordering information matches the exact datasheet revision to avoid discrepancies in electrical characteristics or pinout definitions during procurement.

Selection Notes

Select this component when a stable 2.5 V reference is required in a small surface-mount footprint. The A grade offers a balance of performance suitable for general-purpose precision applications. Consider the 25 ppm/°C temperature coefficient and 5 μV p-p noise levels against system sensitivity requirements. Evaluate the 140 μA quiescent current consumption for battery life calculations in portable designs.

Part Context

This part belongs to the ADR39x family of micropower voltage references, which also includes the ADR392 (4.096 V) and ADR395 (5.0 V). All members share the same architecture, featuring low dropout capabilities and high precision. The ADR391 specifically targets applications requiring a 2.5 V reference standard. The family utilizes patented drift curvature correction techniques to achieve superior thermal stability within the TSOT package.

Replacement Considerations

Direct replacements include other parts within the ADR391 series such as the ADR391BUJZ-R2 for higher precision (B grade). Cross-family alternatives like the ADR3412 exist but differ in pin count and voltage output.