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TCAN4550: Some questions.

Kengo.Y
Guru 11335 points

Part Number: TCAN4550

Hi team,

Could you tell me about my some questions?

1. How much is VOL value when based upon  Vio voltage rail?

2. What kind of output is SDO when SPI is not communication?

3. What is the state of each port(Input and Output) in sleep mode?
　HiZ or High or Low?

4.  What is the state of each port(Input and Output) when no VSUP?
　HiZ or High or Low?

5. Are the following methods of returning from sleep to standby mode correct?
     Local wake up/ RST pin/ power restart
    Are there any disadvantages to using RSTpin?

6. How to processing is unused GPO2pin?

7. What is the difference between Mirrors INH function and Wake request interrupt?

8. What kind of output is SDO when nCS is High?

Sincerely.
Kengo.


  • 0
    Guru 11335 points

    Hi team,

    How about this thread?
    Could you give me your advice as soon as possible?

    Sincerely.
    Kengo.

  • 0 in reply to Kengo.Y
    TI__Guru 74352 points

    Kengo,

    Thank you very much for your patience on this.

    1. VOL is maximum 0.2 * VIO.
    2. The SDO pin is high-impedance when the nCS pin is not engaged, meaning no SPI communication is occurring. So it will depend, if the MCU has an internal pull-up source on the pin connected to TCAN4550-Q1 SDO, then it will be a logic high. Otherwise it will be a logic low.
    3. RST is low, INH is high-impedance, nINT pin is high-impedance, nWKRQ is high-impedance, GPO2 is high-impedance, GPIO1 is high-impedance, VCCOUT is disabled/high-impedance, WAKE pin is enabled and state is dependent on external bias, SPI pins are all high-impedance, OSC1 and OSC2 are high-impedance.
    4. With VSUP not present, the TCAN4550-Q1 will shut everything down, essentially staying in a "RESET" mode. In this mode, all pins are high-impedance until VSUP passes the under voltage threshold. All registers will also be cleared and need to be reconfigured.
    5. There is also the CAN bus wake-up, with a dominant pulse, followed by a recessive pulse, followed by a dominant pulse, that can wake the TCAN4550-Q1. Using a power restart and/or the RST pin clears all the SPI registers. So all configuration would have to be re-written. I would not recommend using the RST pin as a wake mechanism unless you have no other way.
    6. This pin can be left floating if it is not used. If it is connected to the MCU, by default it is configured for no action, so it will not have any effect.
    7. "Mirrors INH function" configuration latches the nWKRQ low when a wake request is received. "Wake request interrupt" configuration asserts nWKRQ low until the internal wake interrupt flag is cleared and then goes back high.
    8. High-impedance

    Please let me know if you have any other questions.

    Regards,

  • 0 in reply to Eric Hackett
    Guru 11335 points

    Eric,

    Thank you so much for your comment.

    I want you to double check your customer's schematic.
    Can I talk with you in a private message?

    Sincerely.
    Kengo.

  • 0 in reply to Kengo.Y
    TI__Guru 74352 points

    Kengo,

    Yes, you can click on my username which will give you my email. You can email me directly to share the customer's schematic.

    Regards,