ADR444ARMZ

Overview

The ADR444ARMZ is an ultralow noise, LDO XFET voltage reference with a fixed output of 4.096 V. It operates within an input voltage range of 4.6 V to 18 V and requires a minimum supply headroom of 500 mV. The device provides a source current of up to 10 mA and a sink current of up to -5 mA. Initial accuracy is ±5 mV (±0.13%), with a temperature coefficient of 10 ppm/°C. Quiescent current is typically 3.75 mA. Noise performance is 1.8 µV p-p from 0.1 Hz to 10 Hz. It is housed in an 8-lead MSOP package and functions over a temperature range of -40°C to +125°C.

Feature Summary

• Utilizes XFET technology for exceptionally low noise and minimal thermal hysteresis.
• Features a dedicated TRIM pin allowing output voltage adjustment over a 0.5% range without compromising performance.
• Capable of sourcing up to 10 mA and sinking up to -5 mA of load current.
• Operates with a low dropout voltage requiring only 500 mV of supply headroom.

Applications

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

Procurement Notes

Verify the specific suffix 'ARMZ' corresponds to the MSOP-8 package configuration. Confirm that the A-grade electrical specifications align with system requirements for initial accuracy and temperature drift. Ensure input voltage constraints are met given the 4.6 V minimum requirement for this specific model variant.

Selection Notes

Select this component when ultralow noise performance is critical for signal integrity. The ADR444ARMZ is suitable for applications requiring precise voltage regulation with minimal power consumption. Consider the trim capability if system-level calibration is necessary to offset initial accuracy errors or long-term drift.

Part Context

The ADR444ARMZ belongs to the ADR44x series of XFET voltage references manufactured by Analog Devices. This family includes models with outputs ranging from 2.048 V to 5.000 V. All variants share common architectural features such as low dropout operation, high output drive capability, and advanced temperature drift curvature correction techniques.

Replacement Considerations

ADR444BRZ: Offers improved initial accuracy (±1.6 mV) and lower temperature coefficient (3 ppm/°C).

FAQ

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

XFET technology utilizes junction field effect transistors (JFETs) with extra channel implants. This results in significantly lower noise generation and reduced thermal hysteresis compared to standard bandgap references, which rely on more complex compensation circuitry.

What is the function of the TRIM pin on the ADR444ARMZ?

The TRIM pin allows users to adjust the output voltage over a 0.5% range. By connecting a potentiometer between the output and ground with the wiper connected to the TRIM pin, system errors can be trimmed out without degrading temperature performance.