Analog Devices Inc. ADR441ARZ

Overview

ADR441ARZ from Analog Devices is an ultralow-noise, low-dropout XFET® voltage reference delivering 2.500 V output with ±1 mV initial accuracy (B grade), 3 ppm/°C temperature coefficient, and 1.2 µV p-p (0.1 Hz to 10 Hz) noise. It sources +10 mA and sinks −5 mA, operates from 4 V to 18 V input, and is used in high-resolution ADC biasing and precision medical sensor front-ends.

For engineers reviewing the ADR441ARZ datasheet, ADR441ARZ pinout, ADR441ARZ application, or ADR441ARZ equivalent, key selection criteria include ultralow 1.2 µV p-p noise, 3 ppm/°C drift over −40°C to +125°C, trim-adjustable output, and SOIC_N package compatibility with space-constrained industrial data acquisition designs.

Technical Context

The ADR441ARZ implements XFET® technology-using two matched JFETs with one featuring an extra channel implant-to generate a stable ~0.5 V intrinsic reference, then applies PTAT-based curvature-corrected amplification to achieve 2.500 V output. Its noise performance stems from minimal correction circuitry versus bandgap references.

It supports bidirectional load current (±10 mA/−5 mA), features a dedicated TRIM pin for 0.5% output adjustment without degrading drift or noise, and maintains regulation with only 500 mV supply headroom-enabling use in low-voltage, battery-powered systems where headroom is constrained.

Key Specifications

Pinout & Package

ADR441ARZ is packaged in an 8-lead SOIC_N (R suffix) with exposed pad not internally connected. Pin 1 and Pin 8 are DNC (Do Not Connect); Pins 3 and 7 are NIC (Not Internally Connected). GND (Pin 4) must be low-impedance; TRIM (Pin 5) enables fine output adjustment.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar voltage reference applications.

Compared with REF5025AIDR and MAX6126AASA25+, the ADR441ARZ uniquely combines 500 mV dropout, TRIM capability, and industry-leading 1.2 µV p-p noise in a standard SOIC_N-making it optimal for high-accuracy, low-headroom, field-calibratable systems.

Availability

ADR441ARZ is available at Aetrix Electronics and suitable for precision data acquisition systems, portable medical instruments, and industrial process control applications requiring stable component supply, long-term calibration retention, and low-noise reference performance.

Supply support for ADR441ARZ includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Analog Devices, Inc. is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, headquartered in Norwood, MA.

The ADR44x family was designed specifically for ultraprecise, low-noise voltage referencing in high-resolution data converters and portable instrumentation-leveraging XFET® technology to surpass traditional bandgap and buried Zener performance limits.

FAQ

What is the output voltage tolerance and temperature coefficient of the ADR441ARZ?

The ADR441ARZ is a B-grade device with nominal output voltage of 2.500 V, initial accuracy of ±1 mV (±0.04%), and temperature coefficient of 3 ppm/°C over −40°C to +125°C. This ensures total output variation remains within ±0.75 mV across its full operating temperature range, making it suitable for metrology-grade applications where thermal stability is critical. The ADR441ARZ specification sheet confirms these values under "ADR441 Electrical Characteristics" Table 3.

Can the ADR441ARZ operate from a 3.3 V supply?

No-the ADR441ARZ requires a minimum input voltage of 4.0 V (VIN ≥ VOUT + 500 mV = 3.0 V, but datasheet specifies VIN ≥ 4 V for ADR441). At 3.3 V, the device falls outside guaranteed operation and may exhibit increased drift, noise, or failure to regulate. For 3.3 V systems, consider the ADR440ARZ (2.048 V output, 3.0 V min input) or verify margin with worst-case headroom analysis. This requirement is explicitly stated in Table 3 of the ADR441ARZ datasheet.

How is the TRIM pin used on the ADR441ARZ, and what is its adjustment range?

The TRIM pin (Pin 5) of the ADR441ARZ allows ±0.5% output voltage adjustment using an external resistor network-typically a 10 kΩ potentiometer between VOUT and GND, with the wiper connected to TRIM. This tuning does not degrade temperature coefficient or noise performance. The ADR441ARZ datasheet Figure 36 and "Output Adjustment" section confirm this configuration and specify the exact 0.5% range, enabling fine calibration without recalibration hardware.

What is the maximum load current the ADR441ARZ can source and sink?

The ADR441ARZ can continuously source up to +10 mA and sink up to −5 mA while maintaining specified accuracy, noise, and thermal performance. These ratings are guaranteed over −40°C to +125°C and appear in Table 3 under "OUTPUT CURRENT CAPACITY". Exceeding −5 mA sink may cause output collapse or increased drift; for higher sink requirements, add an external NPN transistor stage referenced to the ADR441ARZ output.

Does the ADR441ARZ require external capacitors, and if so, what values are recommended?

Yes-the ADR441ARZ requires a 0.1 µF ceramic capacitor on both VIN and VOUT pins for stability and noise reduction, as mandated in the "Basic Voltage Reference Connections" section and Figure 36 of the datasheet. A 10 µF input capacitor is optional but recommended to improve line transient response. All capacitors must be placed as close as possible to their respective pins with short, low-inductance traces to prevent oscillation or degraded noise performance.