• State Resolved
  • Locked Locked
  • Replies 4 replies
  • Answers 1 answer
  • Subscribers 32 subscribers
  • Views 143 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.

TCAN1057AV-Q1: TCAN1057AV

ilya tashaev
Prodigy 125 points

Part Number: TCAN1057AV-Q1

Hello

i have a question about the S pin (8) of TCAN1057AV-Q1 :

in page 3 of the datasheet it says " Digital Input - Silent mode control input, integrated pull-up"

what the "integrated pull-up" means is it already has an internal pull-up resistor ?

or do i need to add a pull-up resistor ?

thanks in advance

  • 0
    TI__Guru 51045 points

    Hi Ilya,

    The TCAN1057A has a very weak (>200k-ohm equivalent) internal pull-up on the Silent mode pin (8). This internal bias is intended to keep the device is a low power mode when this pin is floating such as if the MCU is not active. It is common for applications to include an external pull-up on this pin as well to increase noise immunity and to allow consistent behavior if a different transceiver is introduced here that may have a different or no internal bias. An external pull-up resistor is not required for TCAN1057A. 

    Let me know if you have any more questions. 

    Regards, 
    Eric Schott

  • 0 in reply to Eric Schott1
    Prodigy 125 points

    Hi Eric

    thank you for your fast reply, but i don't understand you at first you said " It is common for applications to include an external pull-up..." and at the end you said "An external pull-up resistor is not required for TCAN1057A"

    so what should be right ?

  • 0 in reply to ilya tashaev
    TI__Guru 51045 points

    Hi Ilya,

    The transceiver does not require an external pull-up in order to operate. If the customer chooses not the include an external pull-up there will be no issue use with TCAN1057A. 

    Many applications are designed for use with multiple transceivers as second sourcing options. Some similar transceivers to TCAN1057A may require an external pull-up on pin 8, so it is common for other solutions to include the option for this component on the board. Including this external pull-up will also be no issue for TCAN1057A, so it is typically recommended to include the pull-up as an option (can be DNP'ed) for flexibility later on. 

    In this case, I would recommend including an external pull-up resistor if space allows but mark it as DNP so there is no associated BOM cost. If space is an issue and the other possible transceiver options do not require an external pull-up resistor, it is fine to omit this option to save space on the PCB. 

    Regards, 
    Eric Schott

  • 0 in reply to Eric Schott1
    Prodigy 125 points

    understood thank you