Hi All, looking for some help on this transceiver
I have marked which pins are high and low for the CAN network. I worked out which was the ground as well, but could not find the power input.
Any help is appreciated.
Hello,
I was not sure on this one either. I sent it to the group so hopefully someone would be able to figure this one out.
Hi ByronT,
I haven’t been able to identify your particular part. It may be a custom part or just one relabeled for a particular customer. However, after looking at the pin-outs of CAN transceivers from multiple vendors, they all seem to have standard pin-outs for all but pins 5 and 8, and almost always “Standby” for pin 8.
On every one I looked at, Vcc (power) was on pin 3, as seen in the image below.
(from pin-out of ATA6561)
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Hi @David_1528 are you thinking then that nearly any CAN transceiver should work?
One thing I forgot to add was that this is on a J1939 CAN circuit.
Thanks,
Byron
Hi ByronT,
Unfortunately, I can’t say that with any certainty. From what I have read, you’ll want one that complies with ISO11898-x, with “x” being different updates over the years. As far as I know, they are backwards compatible, so later ones would likely comply with earlier ones, but I am no expert in this area. If this is to repair a board in a car, then knowing the year might give you an idea which revision of the standard it might have used. I believe some of the older ones were lower speed devices, running up to 250kbps, whereas some of the newer ones can run faster, up to 5Mbps and have “flexible data rate” (CAN FD) capability.
Note that pin 5 has different functionality on some devices. Sometimes, it has no function, but in other cases it is used to set the I/O voltage for the TxD and RxD pins, which communicate with the local MCU or CAN controller IC. These voltages are typically either 5V or 3.0V to 3.3V. Still others use pin 5 for “Silent Mode”, but some put this functionality on pin 8. Others put “Standby” on pin 8.
Examples:
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