Texas Instruments Releases a Family of Hot-Swappable I2C Isolators

Texas Instruments ISO1640 ISO1641 ISO1644

The ISO1644, ISO1640 and ISO1641 (ISO164x) devices, released by Texas Instruments are hot swappable, low-power, bidirectional isolators that are compatible with I2C interfaces. The ISO164x supports UL 1577 isolation ratings of 5000 VRMS in the 16-DW package, and 3000 VRMS in the 8-D package. Each I2C isolation channel in this low emissions device has a logic input and open drain output separated by a double capacitive silicon dioxide (SiO2) insulation barrier. The ISO1644 integrates 3 unidirectional CMOS isolation channels which can be used for static GPIO isolation or to isolate a Serial Peripheral Interface (SPI) bus.

Texas Instruments - ISO1640, ISO1641, ISO1644

This family includes basic and reinforced insulation devices certified by VDE, UL, CSA, TUV and CQC. The ISO1644 and ISO1640 has two isolated bidirectional channels for clock and data lines while the ISO1641 has a bidirectional data and a unidirectional clock channel. The ISO164x family integrates logic required to support bidirectional channels, providing a much simpler design and smaller footprint when compared to optocoupler-based solutions.

Simplified Isolated Bidirectional Data Channel Schematic
Simplified Isolated Bidirectional Data Channel Schematic.


  • Robust Isolated Bidirectional, I2C Compatible, Communication
    • ISO1640: Bidirectional Isolated SDA and SCL communication
    • ISO1641: Bidirectional Isolated SDA and unidirectional SCL communication
    • ISO1644: Bidirectional Isolated SDA and SCL communication with 3 Unidirectional GPIO channels
    • Hot-Swappable SDA and SCL
  • Bidirectional data transfer up to 1.7 MHz Operation
  • Up to 3 additional unidirectional isolation channels supporting speeds up to 50 Mbps operation
  • Supply range:
    • 3 V to 5.5 V (Side 1)
    • 2.25 V to 5.5 V (Side 2)
  • Open-Drain Outputs Sink Current Capability:
    • 3.5-mA (Side 1)
    • 50-mA (Side 2)
  • Max capacitive load:
    • 80 pF (Side 1)
    • 400 pF (Side 2)
  • 16-SOIC (DW-16) and 8-SOIC (D-8) Package Options
  • –40 °C to +125 °C Operating Temperature
The ISO1640DEVM Evaluation Module
The ISO1640DEVM Evaluation Module.

1-4 Layer PCBs $2

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