Analog Devices Inc. ADR441ARMZ

Overview

ADR441ARMZ 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 signal chains.

For engineers reviewing the ADR441ARMZ datasheet, ADR441ARMZ pinout, ADR441ARMZ application, or ADR441ARMZ equivalent, key selection criteria include ultralow 0.1–10 Hz noise performance, trim-adjustable output over ±0.25%, LDO operation with only 500 mV headroom, and guaranteed −40°C to +125°C operation in MSOP package.

Technical Context

The ADR441ARMZ implements Analog Devices' XFET® architecture-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 correction for ultra-low drift. Its noise originates primarily from the JFET channel rather than bandgap compensation circuitry, enabling lower 1/f noise than buried Zener references.

It integrates internal trimming resistors (R2/R3) to set the precise 2.500 V output, supports external adjustment via the TRIM pin over ±0.25% without degrading noise or drift, and maintains regulation under simultaneous sourcing and sinking loads across its full industrial temperature range.

Key Specifications

Pinout & Package

ADR441ARMZ is housed in an 8-lead MSOP (RM suffix) package with exposed pad for thermal enhancement. Pin 1 is DNC (Do Not Connect), Pin 2 is VIN, Pins 3 and 7 are NIC (Not Internally Connected), Pin 4 is GND, Pin 5 is TRIM, Pin 6 is VOUT, and Pins 1 & 8 are DNC.

Key Features

Applications

Equivalent & Alternatives

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

Compared with REF5025IDR and ADR4525BRZ, the ADR441ARMZ uniquely balances ultralow 1.2 µV p-p noise, ±0.25% trim capability, and 500 mV dropout in MSOP-making it optimal for space-constrained, battery-operated, high-accuracy systems requiring field calibration flexibility.

Availability

ADR441ARMZ is available at Aetrix Electronics and suitable for precision data acquisition systems, portable medical instruments, and industrial process control systems requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for ADR441ARMZ 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 ultraprecision, low-noise voltage reference applications in data converters, instrumentation, and medical electronics-leveraging XFET® technology to surpass traditional bandgap and buried Zener performance limits.

FAQ

What is the maximum input voltage rating for the ADR441ARMZ?

The ADR441ARMZ has an absolute maximum input voltage of 20 V, but its specified operating range is 4 V to 18 V. Exceeding 18 V may degrade long-term reliability or cause parametric shift, even if within absolute ratings. For robust design, maintain VIN ≤ 18 V with ≥500 mV headroom above VOUT (i.e., VIN ≥ 3.0 V). The ADR441ARMZ datasheet confirms this in Table 7 (Absolute Maximum Ratings) and Table 3 (ADR441 Electrical Characteristics).

Does the ADR441ARMZ require external capacitors, and if so, what values?

Yes, the ADR441ARMZ requires a minimum 0.1 µF ceramic capacitor on both VIN and VOUT pins for stability and noise performance, as specified in the "Basic Voltage Reference Connections" section (Figure 36) and "Power Dissipation Considerations" (Rev. G, Page 15). A 10 µF input capacitor is optional and improves line transient response. Omitting either 0.1 µF capacitor risks oscillation, increased noise, or degraded PSRR. These requirements apply directly to the ADR441ARMZ in MSOP package per the official Analog Devices datasheet.

Can the ADR441ARMZ sink current while sourcing current simultaneously?

No-the ADR441ARMZ cannot source and sink current simultaneously from the same VOUT node. Its output stage supports sourcing up to +10 mA or sinking up to −5 mA, but not concurrent bidirectional current flow. Load conditions must be unidirectional: either sourcing (e.g., driving an ADC reference input) or sinking (e.g., biasing a current-sinking DAC). Attempting simultaneous sourcing/sinking violates the device's output stage architecture and may cause instability or specification noncompliance. This behavior is defined in the "General Description" and "ADR441 Electrical Characteristics" (Table 3) sections of the ADR441ARMZ datasheet.

What is the purpose of the TRIM pin on the ADR441ARMZ, and how much adjustment does it allow?

The TRIM pin on the ADR441ARMZ enables external fine-tuning of the output voltage over a ±0.25% range (±6.25 mV around 2.500 V) using a resistor divider, as detailed in the "Applications Information" section (Page 16) of the datasheet. This adjustment preserves the device's specified noise, tempco, and long-term stability-unlike post-regulation trimming. The TRIM pin connects to an internal resistive divider network; applying voltage here scales the output without altering the core XFET reference. This feature is unique to the ADR441ARMZ among 2.5 V references in its class.

Is the ADR441ARMZ pin-compatible with other devices in the ADR44x family?

Yes-the ADR441ARMZ shares identical pinout and package (8-lead MSOP, RM suffix) with all ADR44x variants (ADR440/443/444/445), including same VIN, GND, VOUT, TRIM, and DNC/NIC pin assignments. However, output voltage, noise, and input voltage range differ across models (e.g., ADR445 requires ≥5.5 V VIN). Swapping ADR441ARMZ for another ADR44x part requires verifying compatibility with the target output voltage, supply headroom, and load requirements-but no PCB change is needed. This uniformity is confirmed in Figures 4 and 3–4 and Table 9 of the ADR441ARMZ datasheet.