Other Parts Discussed in Thread: THVD1439, TCAN3414, SN65HVD231
Tool/software:
We want to parallel the A/B output of a THVD1439 and the output of the SN65HVD234 CAN transceiver so either standard could be available on our two pin interface. These parts were chosen for their low power consumption when disabled.
We found that when the CAN transceiver was installed in parallel with the 1439 and the 1439 was enabled (RE=0, DE=1) and the 65HVD234 was disabled (?) with Rs=1 and EN=0, the data line shared by both devices had data that was present but never reached below 1/2Vcc. We could understand that the 485 data on D+(CANH) and D-(CANL) might be affected but the item affected is the output of the 485 that is attempting to drive the data line.
I suspect that placing the CAN transceiver in what we think is a disabled state still has the driver on pin 4 (R) enabled and is high so prevents the 1439 from being able to pull data to ground.
Can you recommend a CAN transceiver that disconnects the data side when disabled and has low power consumption. Standby listen is not required.
