We are on the design state of CAN bus product using the PCA82C251 transceiver from Philips. We have used an external circuit for the transceiver protection, but we finally realised that it is not protects the ic.
We found another ic from ST (L9615) that is pin to pin compadible with the one from Philips and also supports short circuit protection.
Our problem here is what to do with the products that have the PCA82C251 soldered on board. We have SMB pads (for protection diodes) at the ic's CanH and CanL pins and after them we have MicroSMD-1206 pads in series (for low current polyswitches) from both CanH and CanL pins to the external connectors.
We analised the protection circuit and we found that the 50mA/4Ohm polyswitches that we use are too slow (0.35 - 1.5sec) to protect the ic.
Is there any idea for what to do to protect the current production?