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TLIN1441-Q1: wake up in standby mode

Chuqiang Wen
Expert 5090 points
Part Number: TLIN1441-Q1
Other Parts Discussed in Thread: TLIN1028-Q1, TLIN1431-Q1

Hi Expert, 

I have some questions about wake up requirement in standby mode. 

Firstly, in customer's use-case, there have some wake up detection requirements on MCU, so they need LDO on to supply MCU, but require lower power consumption in this case. So they can only use standby mode. 

But customer requires that TLIN1441-Q1 is able to detect the wake-up request on LIN bus, then wake up MCU through RXD pin(high to low falling edge can wake up MCU). 

From datasheet, TLIN1441-Q1's RXD is always low level in standby mode. 

Can you confirm if my understanding is correct or not? If yes, it there any workarounds? 

Thanks!

Ethan Wen

  • 0
    TI__Guru 69592 points

    Ethan,

    Let me check with our design team and get back to you. My first thought is that RXD is low in Standby mode always because the expectation is that you're only in Standby mode due to a wake request. However, you can also be in Standby mode upon power-up, and if that's the case, I need to verify if RXD is also low in that case, or if it is high, and if it is high, would it respond to a wake request anyway. 

    Regards,

    Eric Hackett 

  • 0 in reply to Eric Hackett
    TI__Expert 5090 points

    Hi Eric,

    Please help check internally if there have any workarounds. 

    It may have risks in customer's project. 

    And I am confused that the behavior of TLIN1028-Q1 in standby mode is different with TLIN1441-Q1. TLIN1028-Q1 is fully match with customer's requirement. 

    I also checked TLIN1431-Q1, it seems the same behavior with TLIN1441-Q1. May I know the reason behind? 

    Thanks!

    Ethan Wen

  • 0 in reply to Chuqiang Wen
    TI__Guru 69592 points

    Ethan,

    I confirmed that the TLIN1441-Q1 holds RXD low at all times in Standby mode. The reason that TLIN1028-Q1 and TLIN1431-Q1 do not do this is because these devices came after in development and it was decided to give this functionality as a request from multiple customers. We did not update the TLIN1441-Q1 to include this.

    Is the customer using the device in PIN or SPI mode? If they are using SPI mode, the nINT pin would go low upon receiving a WUP from the LIN bus, there's an interrupt for it in register 0x0C. And so that could be an indicator to the MCU to wake it up.

    Regards,

    Eric Hackett