• State TI Thinks Resolved
  • Locked Locked
  • Replies 1 reply
  • Answers 1 answer
  • Subscribers 14 subscribers
  • Views 264 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

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.

ISO7041-Q1: Termination resistor size

Ari Kärkkäinen
Prodigy 10 points
Part Number: ISO7041-Q1

In datasheet (SLLSFN3 / June 2023) there are Table 5-1 : 

ISO7041-Q1 Automotive, Ultra-Low Power Four-Channel Digital Isolator datasheet

"Input, channel A-D. 300-Ω series resistor recommended "

and same for output channels. Why so big resistance values recommended? Some signal integrity issues my arise by using those high values especially in higher data rates. Single ended 50 ohms are usually drived with around between 20 -33 ohms. And elsewhere in the same document there are no example pictures of the use of those resistors. 

  • 0
    TI__Genius 14705 points

    Hello,

    Thank you for your question.

    The 300Ω resistor is recommended to limit the current into the device when the device is accidentally operated by applying signal to INx pins while its VCC pin is not powered. If you do not see this sort of situation happening, then the 300Ω series resistors can be optional.

    The 300Ω series resistors are a typical use case for automotive applications. If the your are using this part for industrial purposes, these resistors are optional as well.

    Regards,
    Aaditya Vittal