Analog Devices Inc./Maxim Integrated MAX14937AWE+T

Overview

MAX14937AWE+T from Maxim Integrated is a two-channel, 5kVRMS galvanically isolated I²C digital isolator with bidirectional open-drain channels, 2.25V–5.5V dual-supply operation per side, DC–1.7MHz data rate, and -40°C to +125°C operating range-designed for isolated sensor interfaces and power management in industrial PLCs and battery monitoring systems.

For engineers reviewing the MAX14937AWE+T datasheet, MAX14937AWE+T pinout, MAX14937AWE+T application, or MAX14937AWE+T equivalent, key selection considerations include its 5kVRMS isolation rating, A-side logic-low regulation (≤0.9V), CMTI ≥25kV/µs, and compatibility with I²C clock stretching in high-noise environments.

Technical Context

The MAX14937AWE+T implements proprietary BiCMOS-based capacitive isolation with two independent bidirectional channels, each featuring asymmetric buffer architecture: Side A uses regulated low-voltage outputs (VOL ≤0.9V) with input thresholds ≥50mV lower to prevent bus latch-up, while Side B employs conventional open-drain buffers. It supports independent supply rails (VDDA/VDDB = 2.25V–5.5V) and operates across full industrial temperature range without sequencing constraints.

Its isolation barrier meets UL1577 (5kVRMS/60s), VDE 0884-11 Basic Insulation (VIORM = 1200VPK, VIOWM = 848VRMS), and IEC 61000-4-5 ±10kV surge immunity. Propagation delays are asymmetrical (e.g., tPLHAB = 20–35ns, tPHLAB = 80–110ns), and pulse-width distortion remains ≤100ns across voltage/temperature ranges-critical for timing-sensitive I²C clock stretching.

Key Specifications

Pinout & Package

The MAX14937AWE+T is housed in a 16-pin wide-body SOIC package (10.3mm × 7.5mm, outline 21-0042) with 8mm creepage/clearance, RoHS-compliant lead-free finish (+T suffix), and internal BiCMOS isolation technology.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar I²C isolator applications.

Compared with ADUM1250ARZ and SI8602ED-B-IS, the MAX14937AWE+T uniquely combines 5kVRMS isolation, true bidirectional open-drain I²C support with A-side logic-low regulation, and guaranteed clock stretching operation-making it the only option for safety-critical, mixed-voltage I²C systems requiring zero-bus-modification integration.

Availability

MAX14937AWE+T is available at Aetrix Electronics and suitable for industrial sensor interfaces, isolated power supply monitoring, and battery management systems requiring stable component supply, long-term lifecycle assurance, and certified safety isolation.

Supply support for MAX14937AWE+T 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

Maxim Integrated (now part of Analog Devices) designs precision analog, mixed-signal, and high-reliability interface ICs for industrial, automotive, and medical applications.

The MAX14937AWE+T belongs to Maxim's high-voltage digital isolator product line, engineered specifically for robust I²C signal isolation in harsh environments where ground loop elimination, surge immunity, and safety certification are mandatory.

FAQ

What is the maximum continuous working isolation voltage supported by the MAX14937AWE+T?

The MAX14937AWE+T supports a maximum continuous working isolation voltage (VIOWM) of 848VRMS per IEC 60747-5-5, validated under DIN VDE V 0884-11 for basic insulation. This rating enables use in industrial equipment with reinforced insulation requirements up to 1200VPK transient voltage, as confirmed in the device's VDE certification file 5015017-4880-0001/272147/TL7/SCT. The MAX14937AWE+T maintains this rating across its full -40°C to +125°C operating temperature range.

Does the MAX14937AWE+T support I²C clock stretching, and how is it implemented?

Yes, the MAX14937AWE+T fully supports I²C clock stretching due to its bidirectional open-drain architecture and asymmetrical buffer design. Side A's regulated logic-low output (≤0.9V) and ≥50mV input threshold margin prevent bus contention during slave-induced clock hold events. The device operates from DC to 1.7MHz and preserves timing integrity even under worst-case clock-stretching conditions-verified in Figure 1 and Table 2 of the MAX14937AWE+T datasheet. This makes the MAX14937AWE+T suitable for interfacing with isolated ADCs and battery fuel gauges that rely on clock stretching.

Can the MAX14937AWE+T operate with different supply voltages on Side A and Side B?

Yes, the MAX14937AWE+T supports independent supply voltages: VDDA and VDDB each range from 2.25V to 5.5V, allowing mixed-voltage operation-for example, VDDA = 3.3V (MCU side) and VDDB = 5V (sensor side). No power-supply sequencing is required; either supply can be powered first or independently. This eliminates external level shifters in systems like isolated temperature monitors where logic and analog domains operate at different rail voltages. The MAX14937AWE+T maintains full functionality and isolation integrity across all valid supply combinations.

What is the purpose of the regulated logic-low output on the A-side pins (I/OA1 and I/OA2) of the MAX14937AWE+T?

The regulated logic-low output on I/OA1 and I/OA2 (VOL ≤0.9V at 3mA) combined with a lower input threshold (VIL ≤0.5V) creates a ≥50mV noise margin to prevent bus latch-up-a critical failure mode in I²C systems. Without this regulation, a low output from Side A could be misinterpreted as a low input on the same side, causing positive feedback and locking the bus. This design ensures reliable bidirectional communication on shared SDA/SCL lines, especially when interfacing with legacy 5V pull-ups. The MAX14937AWE+T's A-side regulation is unique among I²C isolators and directly enables drop-in replacement in existing I²C designs.

How does the MAX14937AWE+T handle undervoltage conditions on VDDA or VDDB?

When either VDDA or VDDB falls below its undervoltage-lockout (UVLO) threshold (1.7V–2.2V with 85mV hysteresis), all I/O pins enter high-impedance state and are pulled high by external pull-up resistors-preventing undefined logic states during brown-out or power sequencing. This behavior is documented in Table 2 and Figures 4–7 of the MAX14937AWE+T datasheet. The UVLO circuit monitors each supply independently, ensuring fail-safe operation even if only one side loses power. This protects downstream devices and maintains system integrity in modular power architectures where supplies may ramp at different rates. The MAX14937AWE+T resumes normal operation automatically once the supply recovers above the UVLO threshold.