Part Number: ISO1050
Hi,
My customer need assistance.
The baud rate is 500K, and there are only two nodes on the line. The two ends of the CAN line are connected in parallel with two 120 Ω Matching resistance. One end of CAN line is connected with board ①, and the other end is connected with board ②. The circuit is as follows:
The following waveform is between CANH and CANL of test board ①,
1. The CAN bus is 35 meters, and the two pins of the CAN chip (iso1050) do not have 1NF ceramic capacitor.
2. The CAN bus is 30 meters, and the two pins of the CAN chip (iso1050) do have 1NF ceramic capacitor.
3. The CAN bus is 8 meters, and the two pins of the CAN chip (iso1050) do not have 1NF ceramic capacitor.
4. On the above circuit, add capacitor y (470pf) on L9 and L10 (near the chip) has no effect to GND_ Can1 (ground). And if a common-mode inductor is added between L5, L9 and L10, it has no effect either.
The waveform between CANH and CANL of test board ② is very regular.
Please help. Thanks.
