SN65HVD234: SN65HVD234DR---CANH and CANL pin voltages are the same

What is the marking? Did you get these chips from an authorized distributor?

Qi,

I just looked up the code on the topside of these devices and they do exist in our system. When you say the voltages are the same, are you saying when you transmit data through TXD to the CAN bus, the voltages are the same? And can you share the schematic and some oscilloscope waveforms?

Regards,

Eric Hackett 

you mean this?

oscilloscope waveforms will be sent after we send the chips to testing organization.

Thank you, the schematic looks good, so no reason why the device would not be functioning from the circuit design. And when you get waveforms, can you get some from the working and non-working devices? I want to compare and understand if the waveforms are constantly following each other or if it's just done in recessive or dominant.

Regards,

Eric Hackett 

after I get the waveforms will send you.

and TI changed the screen printing in recent years, so is it possible that the chip was updated and the board was not updated so it can not keep up?

If so, how can adjust the circuit board to match the chip?

thanks for your patient answer.

Qi,

Nothing in an update would cause the CAN Bus voltages to change unless the device is in a low-power mode inadvertently. Even then, this doesn't make sense. Once we see waveforms, we will be able to narrow down what is going on here.

Regards,

Eric Hackett