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TCAN1043-Q1: TCAN1043-Q1 State transient control

Gabriel Xu
Intellectual 2145 points
Part Number: TCAN1043-Q1

Hi Teams

Customer is using TCAN1043-Q1 in their new project and have few questions about SLEEP mode control.

The power supply connection is the same like below diagram in datasheet.

When we enter the SLEEP mode through MCU output high level in EN pin exceed go-to-sleep time.

The power supply for MCU or VIO pin power off as IHN transient to floating output. 

Base on my understanding, the only way to exist SLEEP MODE is wake up from CAN bus (wakeup from external system)?

Wakeup through WAKE pin is vaild or not when VIO is power off?

  • +1
    TI__Guru 53555 points

    Hi Gabriel,

    The local wake up (LWU) feature on the WAKE pin is available even when Vio is not present. This function is dependant on Vsup so it can remain a valid wake source when INH controls the Vcc and Vio supplies. As long as Vsup is supplied in sleep mode, both LWU and WUP wake sources will be active.

    Let me know if you have any more questions.

    Regards,
    Eric Schott

  • 0 in reply to Eric Schott1
    TI__Intellectual 2145 points

    Hi Eric

    I have more questions about CAN FD.

    It seems CAN FD device could support higher data rate exceed 1Mbps.

    I wondering to know besides hardware difference, is there any software (or protocol) difference between CAN and CAN FD?

  • 0 in reply to Gabriel Xu
    TI__Guru 53555 points

    Hi Gabriel,

    CAN FD can support data rates of 5Mbps or even higher in some cases. While this requires the CAN transceiver to be able to handle these rates, there's some clever protocol decisions that allow these higher speeds to be used. This is done by using variable data rates within the same frame (FD stands for flexible data-rate). While the arbitration and ACK phases of a CAN frame are speed limited by the loop time of the system, the data and crc fields are one-way segments and may be sent using a higher speed. For example, a CAN FD frame may transmit at 500kbps during arbitration before switching to 2Mbps during the data and crc phases in the same frame. After the data phase, the transmission will slow again for the ACK and EOF. 

    Danny Bacic has a good Precision Labs video describing CAN protocol which has a section on CAN FD at around 15:00. I'd recommend checking this out for more information and some good visuals. 

    Regards,
    Eric Schott