TCAN334: Compatibility to automotive CAN transceiver

Markus,

TI's 3.3V CAN transceivers are compatible with the Automotive CAN standard, but not fully compliant. Does the 3.3V transceiver need to work with a 5V transceiver on the bus as well? That will determine if you should go with the TCAN334 or the SN65HVD23x series.

Regards,

Hi Eric,

Yes I think so, so it's definitly an automotive application.
Do you have any automotive compatible CAN transceiver with 3V Supply and much smaller than SOIC8?

BR
Markus

Markus,

EDIT: I was incorrect, the TCAN330, TCAN332, TCAN334, and TCAN337 devices come in the SOT-23 package, which is smaller than the SOIC8 package.

Regards,

Hi Eric,

Ok, so they are compatible but not compliant, correct? So if I want to be compliant to automotive systems, I have to use a 5V CAN transceiver?
It should be as small as possible. So my idea at the moment is, to use a dual voltage regulator for 5V and 3V and use the TCAN1042 with VSON8 with VIO option, so that the 3V microcontroller can be connected.
5V supply is not possible for the microcontroller.

BR
Markus

Markus,

That is correct, the 3.3V CAN transceivers are not fully compliant with ISO 11898 Automotive CAN standard due to specific voltage level requirements for bus signals. There are 3.3V transceivers in a smaller package though.

That approach would work, you'd have to use the TCAN1042V device so that the logic levels of the device (TXD, RXD, STB) would all work at 3.3V logic. You can apply the 3.3V supply for the MCU to the VIO pin for this to work, but yes, a 5V supply will still be needed to power the VCC of the CAN transceiver.

Regards,

Hi Eric,

So in the datasheet of TCAN330, TCAN332, TCAN334, and TCAN337 is mentioned  that they fullfill ISO 11898-2.
In TCAN1042 also the ISO 11898-5 Physical Layer Standard is mentioned so thats why the TCAN3x are not fully compliant, is that correct?

Thanks in advance,

BR

Markus

Markus,

The TCAN1042 is fully compliant to the ISO 11898-2 and -5 standards, you are correct. The difference for the -5 standard is the low power mode specification is included. Not all of the TCAN33x devices have a low power mode.

In the TCAN33x series datsheets, it says "compatible", not compliant. Meaning these transceivers are compatible with transceivers that are compliant with the ISO11898-2 standard, but they don't comply themselves.

Regards,