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Product Info Request: SN65HVD255

Shreenidhi Patil
Expert 3936 points
Other Parts Discussed in Thread: SN65HVD255, TCAN1051

Hello Team 

I have been asked if the part SN65HVD255 is compatible with the 12 -24 volt system by my customer VVDN

They came across this spec in one of the competition data sheet “MCP2551”

Can you please help me out here

Also can you help me understand this 12 -24 voltage system and its significance in TCAN devices , will help me answer if any such questions are posed in the future(may be some article or app note would do )

 

Thank you 

  • 0
    TI__Mastermind 20820 points
    Hi Shreenidhi,

    12, 24, and 48V systems refers to the battery voltage that is used in the automobile. Historically cars and trucks have run off of 12V battery systems but new technology and design requirements are pushing them to 24 and 48V systems especially in HEV applications.

    The SN65HVD255 will work in these systems because the node or ECU (electrical control unit) will contain a regulator which will take the battery voltage and provide the required 5V and 3.3V for uP.

    The thing to look for when considering a device for these systems is the bus standoff voltage or bus fault protection. In these systems there is a chance that the bus pins can be shorted to the battery voltage accidentally and developers want to make sure that the transceiver can survive this. Typically developers look for 2x margin when it comes to this spec but 48V systems make this hard to achieve since the voltage is so high. We can use the SN65HVD255 as an example here. The HVD255 supports -27 to 40V of bus fault which makes them suitable for 12V and 24V systems. The 2x margin is not a hard requirement y every OEM it is something we have heard a lot of though. Our TCAN1042 and TCAN1051 devices support up to ±70V of bus fault protection which make them suitable for 12, 24, and 48V systems.

    The MCP2551 has a more symmetrical protection cell with ±42V of bus fault protection and are slightly higher than the 40V that we provide. This should not be a reason to lose the socket though as 2V difference on the high side is really does not provide tons of extra margin. On the low side (GND) microchip may have a better story with 13V of added protection as the battery voltage could be shorted to the chassis of the car there by exposing ground to an over voltage condition.

    Why is VVDN using the MCP2551? Any particular reason? I was thinking it may be for the slope control feature but the SN65HVD255 does not support this so maybe the microchip part is CAN transceiver that they have historically used across their designs. The SN65HVD255 has far superior ESD performance to the MCP2551 as well. In any case we have a solution to meet their needs weather it is high bus fault protection or slope control.
    I hope this information helps, please let me know if you have any more questions?