ADR431ARZ

Overview

The ADR431ARZ is a precision series voltage reference from the XFET family, manufactured by Analog Devices Inc. It provides a fixed output voltage of 2.5 V with an initial accuracy of ±0.12% (A Grade) and a maximum temperature coefficient of 10 ppm/°C. The device operates within a supply voltage range of 4.5 V to 18 V and draws a typical quiescent current of 800 µA. It features ultralow noise performance of 3.5 µV p-p in the 0.1 Hz to 10.0 Hz frequency band. The component supports sourcing up to 30 mA and sinking up to -20 mA of load current. It is housed in an 8-lead SOIC package and functions reliably across an extended industrial temperature range of -40°C to +125°C.

Feature Summary

• Utilizes XFET technology for low noise and minimal thermal drift curvature correction.
• Capable of sourcing 30 mA and sinking 20 mA without external components.
• Includes a dedicated trim terminal for adjusting output voltage over a ±5% range.
• Requires no external bypass capacitor for stable operation.

Applications

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

Procurement Notes

Verify that the specific part number matches the required package type, as the ADR431 series is available in both MSOP and SOIC configurations. Confirm the grade suffix corresponds to the necessary temperature coefficient and accuracy specifications. Ensure compatibility with the intended operating voltage range and load current requirements before finalizing procurement.

Selection Notes

Select the ADR431ARZ when a fixed 2.5 V reference is needed with high accuracy and low noise. Consider this component for designs requiring significant load drive capability compared to standard Zener references. Evaluate the trade-off between the lower headroom requirement and the specific noise density characteristics against other XFET variants in the series.

Part Context

This component belongs to the ADR430/ADR431/ADR433/ADR434/ADR435 series of XFET voltage references. These devices share common architectural features such as low supply current and high output drive capabilities. The ADR431 variant specifically targets applications requiring a 2.5 V output level, distinguishing it from other members of the family that offer different nominal voltages like 2.048 V or 5.000 V.

Replacement Considerations

Direct substitutes within the same family include the ADR431BRZ for tighter temperature coefficients. Other models in the series may serve as alternatives if different output voltages are acceptable. Verify pinout compatibility and package dimensions when considering cross-references from other manufacturers.

FAQ

What is the purpose of the COMP pin on the ADR431?

The COMP pin serves as the compensation input. Connecting a series resistor and capacitor network from this pin to the VOUT pin allows users to reduce overall noise performance.

Does the ADR431 require an external capacitor for stability?

No external capacitor is required for basic operation. However, adding capacitors can be used to further filter noise or manage transient responses depending on the specific application needs.