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TCAN1043A-Q1: power saving issue

Lawrence He
Genius 3115 points
Part Number: TCAN1043A-Q1


Tool/software:

Hi, Support Team

Please help to check below description.

Remove TCAN1043A Vbat power for low power mode saving power.

 

"I want to clarify that when TCAN1043A is in Sleep mode, INH is high-impedance so the INH line should be low.

VSUP (also labeled VBAT) must be connected for the device to operate. However a design could be created to connect/disconnect the VBAT line so as to save even more power. Just note that powering on the device from a cold start (VBAT=0 -> VBAT = 12V for example), the start up time is around 310 us. This is tPWRUP in the datasheet. "

 

And how to understand is right?

  1. That should ADD a POWER SWITCH for power-on TCAN1043A. Then when we need reduced power from battery in bus is off.

 

or

 

  1. We can just remove TCAN1043A's Vbat power. For we don't need using wake this function.

 

 

Because our schematic shown as below:

 

TCAN1043A 's VBAT is no connect to any power

WER3201 is NC

if any suggestion, Please advise me.

Thanks,

Best regards,

Lawrence

  • 0
    TI__Genius 17532 points

    Hi Lawrence,

    Thanks for reaching out on E2E.

    Lawrence He said:
    I want to clarify that when TCAN1043A is in Sleep mode, INH is high-impedance so the INH line should be low

    This is correct. Table 8-4 in the datasheet shows this:

    Lawrence He said:
    VSUP (also labeled VBAT) must be connected for the device to operate. However a design could be created to connect/disconnect the VBAT line so as to save even more power. Just note that powering on the device from a cold start (VBAT=0 -> VBAT = 12V for example), the start up time is around 310 us. This is tPWRUP in the datasheet.

    This is also correct. Just note that the device will be fully shutdown unless VBAT is supplied. So if there is a CAN bus wake up pattern (WUP) while VSUP is off, then the transceiver will not be able to power on. 

    Lawrence He said:

    And how to understand is right?

    1. That should ADD a POWER SWITCH for power-on TCAN1043A. Then when we need reduced power from battery in bus is off.

    I am not sure I understand what the question is here. Please clarify. A switch can be used to toggle the VSUP supply line for TCAN1043A to minimize power. TCAN1043A's VSUP power can be temporarily removed while not in use. Once CAN bus communication is required, VSUP must be supplied for the device to power on and operate. 

    If you are looking for a simpler device without VSUP (so only VCC and VIO), then I would recommend an 8-pin device like TCAN1044A or TCAN1057A. These devices might achieve the functionality for your design without VSUP being required. 

    Best,

    Ethan