Analog Devices Inc. ADUM2281ARIZ

Overview

ADuM2281ARIZ from Analog Devices is a 5 kVRMS dual-channel digital isolator using iCoupler® transformer-based technology, providing bidirectional signal isolation between two independent circuits. It delivers up to 100 Mbps data rate, 24 ns maximum propagation delay, and 3 V to 5.5 V supply compatibility per side-enabling level translation across the isolation barrier. It is used in medical equipment RS-485 interfaces requiring reinforced insulation and high common-mode transient immunity.

For engineers reviewing the ADuM2281ARIZ datasheet, ADuM2281ARIZ pinout, ADuM2281ARIZ application, or ADuM2281ARIZ equivalent, this page provides verified specifications, safety certifications (UL 1577, VDE 0884-17), default-high output behavior, SOIC-16WB package details, and real-world design context for industrial and medical isolation systems.

Technical Context

The ADuM2281ARIZ implements monolithic air-core transformer coupling with integrated CMOS interface circuitry on both sides, eliminating LED aging and timing drift issues of optocouplers. Its patented refresh circuit ensures DC-correct output states during input inactivity or power-up transients.

It supports mixed-voltage operation (e.g., 3.3 V side ↔ 5 V side), features <2 ns pulse width distortion (C grade), and achieves channel-to-channel matching of ≤5 ns. The device maintains >25 kV/μs common-mode transient immunity while operating from −40°C to +125°C ambient temperature.

Key Specifications

Pinout & Package

ADuM2281ARIZ uses a 16-lead SOIC wide-body (SOIC_WB) package with enhanced creepage distance (8.7 mm). Pin 1–8 form Side 1 (input side); Pins 9–16 form Side 2 (output side). Ground pins are grouped (GND1 on Pins 1 & 7; GND2 on Pins 9 & 16) to minimize ground loop impedance.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-channel digital isolator applications.

Compared with ADuM2281ARIZ, ADuM2201ARWZ trades speed and DC stability for lower cost and power, while SI8621ED-IS offers comparable speed but lacks medical-grade certification and requires layout changes-making ADuM2281ARIZ optimal for safety-critical, high-speed, mixed-voltage isolation.

Availability

ADuM2281ARIZ is available at Aetrix Electronics and suitable for medical diagnostics equipment, industrial PLC modules, and renewable energy inverters requiring stable component supply with long-term lifecycle assurance.

Supply support for ADuM2281ARIZ 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 semiconductor company specializing in high-performance analog, mixed-signal, and digital signal processing technologies for precision instrumentation, industrial, and healthcare applications.

The ADuM228x family was designed specifically for high-reliability, safety-certified digital isolation in medical, industrial, and energy infrastructure systems-leveraging iCoupler® technology to replace aging optocouplers with superior speed, longevity, and temperature stability.

FAQ

What is the default output state of ADuM2281ARIZ during power-up or input-side undervoltage?

ADuM2281ARIZ has a default-high output behavior: when VDD1 is unpowered or below UVLO threshold (2.4 V), both VOA and VOB assert high. This is confirmed in Table 23 (ADuM2281 Truth Table) and enables fail-safe initialization in medical and industrial control systems. The ADuM2281ARIZ maintains this state until valid input transitions occur after stable VDD1/VDD2 are applied.

Does ADuM2281ARIZ support level translation between 3.3 V and 5 V logic domains?

Yes, ADuM2281ARIZ supports true bidirectional level translation: VDD1 can be 3.3 V while VDD2 is 5 V (or vice versa), with logic thresholds scaling to 0.3×/0.7× respective supply voltages. This is validated in Tables 7 and 10 (Mixed 5 V/3 V and 3 V/5 V operation), enabling direct interfacing between low-voltage MCUs and higher-voltage peripherals without external level shifters.

What safety certifications apply to ADuM2281ARIZ, and which standards do they cover?

ADuM2281ARIZ is certified to UL 1577 (5000 VRMS), DIN EN IEC 60747-17 (VDE 0884-17) for reinforced insulation (645 VPEAK), IEC/CSA 60601-1 (2-MOPP), and IEC/CSA 62368-1. These approvals are explicitly listed in Table 14 and confirm suitability for patient-connected medical devices and industrial equipment requiring high isolation integrity.

How does the refresh circuit in ADuM2281ARIZ ensure DC correctness?

The ADuM2281ARIZ incorporates a patented internal refresh circuit that periodically samples input states and updates outputs-even during extended periods of input inactivity. As specified in the General Description and Figure 4 timing diagrams, this ensures outputs remain valid and match inputs without drift, unlike optocouplers that lose state during static conditions. Refresh period is 1.6 µs (Table 4).

Is ADuM2281ARIZ pin-compatible with other Analog Devices isolator families?

Yes, ADuM2281ARIZ is pin-compatible with the ADuM2201/ADuM2211 families (per Figure 2), allowing drop-in replacement in existing designs. However, differences exist in data rate (ADuM2281ARIZ supports up to 100 Mbps vs. 10 Mbps for ADuM2201), propagation delay (24 ns vs. 50 ns), and refresh capability-so performance validation is required when upgrading.