Texas Instruments ISO1643DWR

Overview

ISO1643DWR from Texas Instruments is a reinforced-isolation, hot-swappable, bidirectional I²C isolator with two unidirectional GPIO channels. It provides 5000 VRMS isolation rating in a 16-SOIC (DW-16) package, supports up to 1.7 MHz I²C operation, and delivers ±100 kV/μs CMTI - designed for isolated sensor interfaces in industrial motor control systems.

For engineers reviewing the ISO1643DWR datasheet, ISO1643DWR pinout, ISO1643DWR application, or ISO1643DWR equivalent, key selection criteria include its dual-side supply flexibility (3–5.5 V on Side 1, 2.25–5.5 V on Side 2), 50 Mbps GPIO data rate, open-drain output drive (3.5 mA Side 1 / 50 mA Side 2), and compliance with UL 1577, VDE 0884-11, and IEC 62368-1 safety standards.

Technical Context

The ISO1643DWR implements dual capacitive SiO₂ isolation barriers separating Side 1 (SDA1/SCL1/VCC1/GND1) and Side 2 (SDA2/SCL2/VCC2/GND2), with two dedicated unidirectional CMOS GPIO channels (INA/OUTA and INB/OUTB). Its internal logic enables true bidirectional I²C communication without external pull-ups across the barrier.

It features independent UVLO thresholds per side (VCC1: 2.7 V rise / 2.3 V fall; VCC2: 2.0 V rise / 1.7 V fall), 80 pF max capacitive load on Side 1 and 400 pF on Side 2, and operates across –40°C to +125°C ambient temperature - supporting robust hot-swap capability during live bus insertion.

Key Specifications

Pinout & Package

ISO1643DWR uses a 16-pin SOIC (DW-16) package with 10.30 mm × 7.50 mm body size and reinforced isolation barrier. Pin 1 is VCC1; pins 9 and 16 are GND2; pins 1, 3, 5, 6, 11, 12, 14, and 16 form the functional interface; all NC pins (2, 4, 7, 10, 13, 15) must remain unconnected.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ISO1642DWR and ADUM1250ARZ, ISO1643DWR uniquely combines reinforced 5000 VRMS isolation, 1.7 MHz I²C throughput, and two fully configurable GPIO channels in a single 16-pin SOIC - reducing BOM count and PCB area versus hybrid solutions.

Availability

ISO1643DWR is available at Aetrix Electronics and suitable for industrial motor control, Power over Ethernet (PoE), battery management systems, and isolated SMBus/PMbus interfaces requiring stable component supply and long-term design-in support.

Supply support for ISO1643DWR 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 company delivering analog and embedded processing solutions for industrial, automotive, and communications markets.

The ISO164x family was engineered specifically for robust, hot-swappable I²C isolation in noisy, safety-critical environments - emphasizing high CMTI, reinforced certification, and integrated GPIO to replace optocoupler-based designs.

FAQ

What is the maximum I²C data rate supported by ISO1643DWR?

The ISO1643DWR supports up to 1.7 MHz I²C operation under recommended conditions (C1 ≤ 80 pF, C2 ≤ 400 pF). This enables Fast-mode Plus compliance and accommodates higher-speed sensor and power management ICs without protocol translation. The actual achievable rate depends on bus capacitance and pull-up strength - lower capacitance allows marginally higher frequencies, but 1.7 MHz is the guaranteed specification for ISO1643DWR across its full operating temperature range.

Does ISO1643DWR support hot-swap capability on both SDA and SCL lines?

Yes, ISO1643DWR supports hot-swappable operation on both SDA and SCL lines. Its internal architecture prevents bus contention and latch-up during live insertion by managing bidirectional signal flow through dual capacitive isolation barriers. This behavior is explicitly validated in the ISO164x family datasheet and distinguishes ISO1643DWR from unidirectional isolators or legacy optocoupler-based solutions that require bus reset after insertion.

What safety certifications apply to ISO1643DWR?

ISO1643DWR carries UL 1577 Component Recognition (5000 VRMS), DIN VDE V 0884-11:2017-01 (reinforced), IEC 62368-1, IEC 61010-1, and IEC 60601-1 certifications. These confirm compliance with reinforced insulation requirements for industrial, test & measurement, and medical auxiliary equipment. Certification documentation is publicly available via TI's product folder and authorized distributor portals for ISO1643DWR.

Can ISO1643DWR operate with different supply voltages on Side 1 and Side 2?

Yes, ISO1643DWR supports independent supply rails: Side 1 accepts 3–5.5 V (VCC1), while Side 2 accepts 2.25–5.5 V (VCC2). This enables level-shifting between 3.3 V microcontrollers and 5 V peripheral ICs, or interfacing with ultra-low-power 2.5 V sensors. The device maintains full I²C functionality and GPIO operation across this entire voltage combination range - a key design advantage confirmed in Section 6.3 of the ISO1643DWR datasheet.

How many GPIO channels does ISO1643DWR provide, and what are their electrical characteristics?

ISO1643DWR integrates two unidirectional CMOS GPIO channels (INA/OUTA and INB/OUTB) rated for up to 50 Mbps data rate. Each channel supports 5 V, 3.3 V, or 2.5 V logic levels with defined VIH/VIL thresholds (0.7×VCCI and 0.3×VCCI), ±10 µA input leakage, and 4 mA output drive capability. Unlike ISO1642DWR, ISO1643DWR configures INB/OUTB as bidirectional - allowing flexible use as input or output depending on system needs.