Texas Instruments ISO7831FDWR

Overview

ISO7831FDWR from Texas Instruments is a reinforced triple-channel digital isolator with 8000VPK isolation voltage, 100Mbps signaling rate, and ±100kV/μs CMTI. It features two forward and one reverse-direction channels, enable-controlled high-impedance outputs, and operates across 2.25V–5.5V supplies on both sides. It is used in motor control systems to isolate gate drivers from MCU logic while maintaining timing integrity under high dv/dt noise.

For engineers reviewing the ISO7831FDWR datasheet, ISO7831FDWR pinout, ISO7831FDWR application, or ISO7831FDWR equivalent, this page delivers verified specifications, validated SOIC-16 wide-body (DW) package mapping, functional channel directionality, safety certification alignment (VDE 0884-17, UL 1577), and real-world EMC performance data for industrial power and medical isolation design.

Technical Context

The ISO7831FDWR implements capacitive SiO₂-based isolation with three independent channels: two unidirectional (IN→OUT) and one reverse-direction (OUT→IN). Its dual-supply architecture supports asymmetric 2.25V–5.5V operation on input (VCCI/GNDI) and output (VCCO/GNDO) sides, enabling level translation without external circuitry.

It integrates active enable pins (EN1, EN2) for per-side output tri-state control-critical for multi-master bus arbitration-and exhibits fail-safe default behavior: outputs go low upon input-side power loss. Propagation delay is 11ns typical at 5V, with <4.2ns pulse width distortion and <2.5ns channel-to-channel skew for precise timing-critical interfaces.

Key Specifications

Pinout & Package

ISO7831FDWR uses the SOIC-16 wide-body (DW) package (10.30mm × 7.50mm), optimized for 8mm creepage/clearance and reinforced isolation integrity. Pin layout separates input-side (VCCI, GNDI, INA/INB/INC, EN1) and output-side (VCCO, GNDO, OUTA/OUTB/OUTC, EN2) terminals with NC pins (6, 11) providing internal spacing.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ISO7831FDWR, ISO7731FDWR offers identical form-factor and speed but lacks 8000VPK reinforcement for ultra-high-voltage systems, while ADUM3481BRSZ trades bandwidth and enable control for higher channel density in space-constrained designs.

Availability

ISO7831FDWR is available at Aetrix Electronics and suitable for industrial motor control, solar inverter DC-link monitoring, and medical imaging power supply designs requiring stable component supply, long-term lifecycle assurance, and certified reinforced isolation.

Supply support for ISO7831FDWR 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 isolation technologies, with decades of expertise in safety-certified interface solutions.

The ISO7831x family was designed specifically for high-noise, high-voltage industrial and automotive applications demanding reinforced isolation, low-latency communication, and robust EMC performance in compact SOIC packages.

FAQ

What is the default output state of ISO7831FDWR during input-side power loss?

The ISO7831FDWR has a fail-safe default: when VCCI drops below 1.7V, all outputs transition low within 9μs. This behavior prevents unintended activation of downstream gate drivers or actuators in motor control and power supply applications, directly enhancing system safety. The ISO7831FDWR's reverse-channel (OUTC) also follows this low-default state, ensuring consistent fault response across all three channels.

Does ISO7831FDWR support level translation between different supply voltages?

Yes, ISO7831FDWR supports true bidirectional level translation: VCCI can operate from 2.25V to 5.5V independently of VCCO, which also ranges from 2.25V to 5.5V. This allows direct interfacing between a 3.3V microcontroller (VCCI) and a 5V isolated gate driver (VCCO) without external level shifters. The ISO7831FDWR maintains full 100Mbps signaling rate and ±100kV/μs CMTI across all valid supply combinations.

How does the enable functionality work on ISO7831FDWR?

ISO7831FDWR provides two independent enable pins: EN1 controls the forward outputs (OUTA, OUTB), and EN2 controls the reverse output (OUTC). When pulled low, each respective output enters high-impedance state-enabling multi-master bus sharing and dynamic power gating. EN1/EN2 are internally pulled up, so leaving them open enables normal operation. This feature is implemented in hardware within the ISO7831FDWR and requires no configuration registers or firmware overhead.

What safety certifications apply to ISO7831FDWR?

ISO7831FDWR is certified to DIN EN IEC 60747-17 (VDE 0884-17) for 8000VPK reinforced isolation, UL 1577 for 5.7kVRMS withstand voltage, and carries IEC 61010-1, IEC 62368-1, IEC 60601-1, and GB 4943.1 approvals. These certifications are explicitly listed in TI's official documentation for the ISO7831FDWR part number-not just the family-and validate its use in medical, industrial, and EV safety-critical subsystems.

Can ISO7831FDWR replace ISO7831DWR in an existing design?

No-ISO7831FDWR and ISO7831DWR differ in default output behavior: ISO7831FDWR defaults low on input power loss, while ISO7831DWR defaults high. Swapping them without circuit review risks unsafe states (e.g., unintended gate turn-on). Both share identical pinout, package, and electrical specs, but the "F" suffix denotes a functional variant with inverted fail-safe logic, making them non-interchangeable without system-level validation.