ISOW1044: Bus fault greater than specified maximum in datasheet

Jacob Wyrick

Part Number: ISOW1044

Hi team,

We're really considering the ISOW1044 because of it's integrated secondary power supply which is offering savings in our system. However, with current product specs, we have to be able to survive +/-80V.

Does TI have any guidance to protect the CAN bus/CANx pins for short-to-battery transients that exceed the absolute maximum ratings?

Any common, external circuitry that we could implement?

Thanks,

Jacob

over 2 years ago

+1 Koteshwar Rao over 2 years ago

TI__Guru 55785 points

Hi Jacob,

Thanks for reaching out.

If the ±80V requirement is for transients that last a few 10s of µs or less than the best way to protect against such transients is to use TVS diodes. The TVS diodes work very well to clamp transients to the clamping voltage they are designed for. Please see below a document that explains how to choose the TVS diode for protecting CAN bus.

How to Design Isolated CAN Systems With Correct Bus Protection

I am also sharing below a reference design that describes various protection components that can be used to protect CAN bus. Thanks.

https://www.ti.com/tool/TIDA-00629

Regards,
Koteshwar Rao

Isolation

Isolation forum

ISOW1044: Bus fault greater than specified maximum in datasheet