PCA82C251- Resistance between CANH and CANL

[AikangPhil]

We bought two batch PCA82C251 chip:

Old batch:82C251Y /5504/D940

New batch:82C251Y /3502/D037

We faced the CAN communication problem with the new batch(82C251Y /3502/D037),and we measured the resistance between CANH and CANL ,The R=64KΩ，It's higher than the old batch(82C251Y /5504/D940),The R of old batch =37KΩ.

So we wonder the new batch (82C251Y /3502/D037) might be the fake chip ,could you please explain this for me, thank you very much.

[guoweisun]

HI

Please refer to datasheet parameter-Rdiff range is from 20K to 100K,you test result for two lot within this range,no problem for this ICs.

[AikangPhil]

Thank you very much for your answer. but we faced the communication problem, It looks the R may influence the communicate rate ? And we used the 37KΩ ICs without any problem for the past several years, How can we buy the selected 37KΩ ICs, does the factory have methods to control it? if possbile, you can call me to discuss it ,my phone: 13794495859

Thank you very much.

[guoweisun]

Hi

We can't control this parameter because they are within spec.

can you share with your schematic?

[AikangPhil]

Thank you very much, I will share this with our engineer.