ADR423ARZ

Overview

The ADR423ARZ is an ultraprecision, low noise XFET voltage reference providing a nominal output of 3.00 V. It features a maximum initial accuracy of 0.13% and a temperature coefficient of 3 ppm/°C. The device operates within a supply voltage range of 5 V to 18 V with a maximum quiescent current of 500 µA. It delivers up to 10 mA of output current and maintains long-term stability of 50 ppm per 1000 hours. The component is housed in an 8-lead SOIC package and functions reliably across an extended industrial temperature range from -40°C to +125°C.

Feature Summary

• Utilizes patented eXtra implanted junction FET (XFET) technology for superior accuracy and thermal hysteresis compared to band gap references.
• Features a dedicated trim terminal allowing output voltage adjustment over a ±0.5% range without compromising temperature coefficients.
• Provides exceptionally low noise performance suitable for precision conversion applications.
• Offers high output current capability and wide operating input voltage range.

Applications

• Precision data acquisition systems
• High resolution converters
• Battery-powered instrumentation
• Portable medical instruments
• Optical network control circuits

Procurement Notes

Verify the specific electrical grade required for the application, as the datasheet defines distinct A Grade and B Grade specifications for initial accuracy and temperature coefficient. Confirm that the selected package variant matches the board layout requirements, as the series is available in both 8-lead SOIC and MSOP footprints. Ensure the design accounts for the minimum supply voltage headroom relative to the load current to maintain regulation.

Selection Notes

Select the ADR423ARZ when a stable 3.00 V reference is needed with minimal noise and drift. Consider the B Grade if tighter initial accuracy and lower temperature coefficients are critical. Evaluate the power dissipation based on the input voltage and load current to ensure the junction temperature remains within absolute maximum ratings. Verify compatibility with the system's serial interface or converter requirements regarding reference sharing capabilities.

Part Context

The ADR423ARZ belongs to the ADR42x family of second-generation XFET voltage references manufactured by Analog Devices. This series includes variants with different nominal output voltages, such as the ADR420 (2.048 V), ADR421 (2.500 V), and ADR425 (5.000 V). All members share the same core architecture, offering low noise, high accuracy, and excellent long-term stability in compact surface-mount packages.

Replacement Considerations

Direct functional substitutes within the same series include the ADR420, ADR421, and ADR425, provided the specific output voltage requirement can be met by the alternative part number.

FAQ

How does the XFET technology differ from standard band gap references?

XFET technology uses two junction field-effect transistors with different pinch-off voltages to generate a reference. This results in a much lower intrinsic temperature coefficient and significantly reduced noise compared to band gap references, which rely on compensation circuitry that generates additional noise.

Can the output voltage be adjusted using the TRIM pin?

Yes, the TRIM pin allows for output voltage adjustment over a ±0.5% range. To maintain optimal performance, low temperature coefficient resistors should be used in the trimming circuit to avoid degrading the device's temperature coefficient.

Is an output capacitor required for stability?

No, the ADR42x devices do not require output capacitors for stability under any load condition. However, adding a small capacitor (e.g., 0.1 µF) can help filter out low-level noise, while larger capacitors may improve transient response at the cost of increased turn-on time.