• State TI Thinks Resolved
  • Locked Locked
  • Replies 1 reply
  • Answers 1 answer
  • Subscribers 14 subscribers
  • Views 88 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

ISOW1432: GPIO Pins

Venkata Rami Reddy Vempati
Intellectual 265 points

Part Number: ISOW1432

Hi Team,
part Number: ISOW1432DFMR

Regarding GPIO pins, what is the purpose of IN and OUT pins, and what are their key features?

 

  • 0
    TI__Genius 15920 points

    Hi Venkata,

    Thanks for reaching out. Please find my inputs below:

    The IN and OUT pins on the ISOW1432DFMR form a dedicated 2 Mbps unidirectional GPIO channel that transmits digital signals across the galvanic isolation barrier, independent of the RS-485 transceiver. This channel eliminates the need for a separate digital isolator or optocoupler for auxiliary signals [1][2].

    • IN (Pin 14): General-purpose logic input on the isolated (bus) side
    • OUT (Pin 7): General-purpose logic output on the non-isolated (MCU) side

    The signal flows from IN → across the SiO₂ capacitive isolation barrier → OUT

    Note: "IN" here stands for the GPIO input pin, not "Intelligent Network."

    Typical Use Cases

    The GPIO channel is designed for transmitting diagnostic or status signals from the bus side back to the MCU, such as:

    • Power-good monitoring (e.g., connecting VISOOUT to IN to confirm isolated supply presence)
    • Fault indicators or LED control
    • Isolation barrier health monitoring

    Unused Pin Handling

    Pin
    If Unused
    IN
    Tie to GND (default LOW state) to minimize power consumption and noise coupling
    OUT
    Can be left floating — outputs don't pick up noise

    Summary

    The IN/OUT GPIO channel provides a simple, isolated digital path for auxiliary signals, letting you monitor bus-side power status or transmit control signals to the MCU without adding discrete isolation components to your design.

    You can also refer "Applications" section in this app brief for example use case of GPIO pin - Optimize Your Design with Isolated RS-485 Transceivers with Integrated Power

    Regards
    Varun