Texas Instruments ISO7641FMDW

Overview

ISO7641FMDW from Texas Instruments is a quad-channel digital isolator with three forward and one reverse-direction signal channels, galvanic isolation up to 6000 VPK (1 min UL 1577), 150-Mbps signaling rate, 7-ns typical propagation delay, and fail-safe low-state output default. It operates across 2.7–5.5-V dual supplies (VCCI/VCCO) and supports industrial fieldbus, servo control, and motor drive interfaces.

For engineers reviewing the ISO7641FMDW datasheet, ISO7641FMDW pinout, ISO7641FMDW application, or ISO7641FMDW equivalent, key selection factors include channel directionality (3F/1R), dual-supply voltage flexibility (2.7/3.3/5 V), reinforced isolation certification (VDE 6000 VPK, CQC GB4943.1), fail-safe behavior, and SOIC-16 wide-body package compatibility.

Technical Context

The ISO7641FMDW implements capacitive SiO₂-based galvanic isolation with four independent channels: three unidirectional (A/B/C) and one bidirectional-capable reverse channel (D), each buffered by TTL-input-compliant logic and 5-V-tolerant inputs at 3.3-V/2.7-V supply. It features two isolated power domains (VCCI/GND1 and VCCO/GND2) enabling level-shifting between subsystems.

Fail-safe operation defaults all outputs low upon input loss or power failure; enable pins EN1 (controls OUTD) and EN2 (controls OUTA/OUTB/OUTC) provide per-channel or grouped shutdown. Transient immunity reaches 50 kV/μs (typical) under common-mode noise, supporting robust operation in noisy industrial environments.

Key Specifications

Pinout & Package

ISO7641FMDW uses a wide-body SOIC-16 (DW) package measuring 10.30 mm × 7.50 mm with creepage/clearance optimized for reinforced insulation. Pin 1 is marked via dot; pin 1–8 reside on left side, pin 9–16 on right side (top view).

Key Features

Applications

Equivalent & Alternatives

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

Compared with ISO7640FMDW and ADUM1401ARWZ, ISO7641FMDW uniquely delivers 3F/1R channel topology with fail-safe low default and 50-kV/μs CMTI-making it the only option for robust, standards-compliant Modbus/RS-485 isolation in harsh industrial environments.

Availability

ISO7641FMDW is available at Aetrix Electronics and suitable for industrial fieldbus, servo control, and motor drive applications requiring stable component supply, long-term lifecycle assurance, and certified reinforced isolation.

Supply support for ISO7641FMDW 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

Texas Instruments is a global semiconductor leader specializing in analog, embedded processing, and high-reliability interface solutions for industrial, automotive, and communications markets.

The ISO764xFM series was designed specifically for high-speed, safety-certified digital isolation in industrial automation and motor control systems-emphasizing low power, fail-safe behavior, and dual-supply flexibility.

FAQ

What is the channel configuration of ISO7641FMDW?

The ISO7641FMDW has three forward-direction channels (INA→OUTA, INB→OUTB, INC→OUTC) and one reverse-direction channel (IND→OUTD). This 3F/1R topology is optimized for half-duplex industrial protocols like Modbus RTU and RS-485, where dominant master-to-slave traffic coexists with infrequent slave responses. The ISO7641FMDW pinout reflects this asymmetry, with dedicated EN1 and EN2 enables for independent control of the reverse and forward groups.

Does ISO7641FMDW support dual-supply operation?

Yes, ISO7641FMDW supports fully independent dual supplies: VCCI (pins 1, 8, 9) powers the input side and EN2 logic, while VCCO (pins 16, 15) powers the output side and EN1 logic. Each supply accepts 2.7–5.5 V, enabling level translation-for example, interfacing a 3.3-V microcontroller (VCCI) with a 5-V RS-485 transceiver (VCCO). Grounds GND1 and GND2 must remain isolated to maintain galvanic separation.

What happens to outputs during power loss or input fault?

ISO7641FMDW outputs default to LOW in fail-safe mode upon loss of VCCI, VCCO, or valid input signal-guaranteeing a defined state without external components. This behavior is intrinsic to the "F" suffix design and applies to all four outputs (OUTA–OUTD). It prevents undefined logic states in safety-critical applications such as PLC output modules or motor enable circuits, where unintended activation could cause hazardous motion.

What isolation certifications does ISO7641FMDW hold?

ISO7641FMDW is certified for reinforced isolation per UL 1577 (6000 VPK, 1 minute), VDE 0884-10 (6000 VPK transient, 1414 VPK working voltage), CSA Component Acceptance Notice 5A, IEC 60950-1, IEC 61010-1, IEC 60601-1, and CQC GB4943.1. These approvals validate its suitability for medical, industrial, and measurement equipment requiring double-insulation barriers and continuous 400-V RMS working voltage capability.

Can ISO7641FMDW replace optocouplers in existing designs?

Yes, ISO7641FMDW is explicitly positioned as an optocoupler replacement in industrial fieldbus, servo control, and power supply applications. Its 150-Mbps speed, 7-ns propagation delay, and 50-kV/μs CMTI exceed typical optocoupler performance, while its SOIC-16 footprint enables drop-in PCB replacement in many cases. However, verify pin compatibility-ISO7641FMDW uses a specific 3F/1R pinout (e.g., IND on pin 11, EN1 on pin 7) distinct from generic quad isolators.