TCAN1042-Q1: Is there any risk to use a 50mA/5V LDO to drive the CAN transceiver?

Hi Felix,

The maximum ICC for TCAN1042 under normal operation (i.e., a CAN bus with 60-Ohm equivalent load resistance and no short-circuit faults) is 70 mA, so generally the LDO should be chosen to at least source this much current. In some cases the LDO is designed to even maintain proper output regulation in the case of a short-circuit fault; in this case the worst-case ICC is 110 mA.

That said, since often a node spends the majority of the time in the recessive state and the ICC in this state is at most 2.5 mA, you may want to check to see if your LDO is capable of handling larger output currents for short durations as long as the average DC load current is less than 50 mA. (This may be something that depends on the output capacitor value.)

Regards,
Max

Hi Max,

Thanks for your reply.
I just checked with our designer, the maximum LDO output current capability is 80mA and LDO output current limit is 180mA. So from my thought, there will be no problem to use the LDO to provide VCC for the CAN transceiver, is that correct?

Thanks and best regards,
Felix