Question on digital isolator

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FreshmanNewbie

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I am using this IC for Isolated CAN interface (https://www.nve.com/Downloads/il5xx.pdf) - IL514E.

My question is, we are giving 3.3V to VDD1 and isolated 5V to VDD2. Whether there's an internal level shifter? Or is VDD2 a supply output?

Also, can this isolator support CAN-FD speeds?
 

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The linked IC has two isolated circuits, magnetically coupled. Each circuit needs it's own supply voltage (which you have to isolate also, incl GND(!)).
CAN-FD can go up to 5Mbps, the linked IC only supports 2Mbps.

But where are you going to place this IC? In the RX/TX lines to the CAN PHY?
As it can only handle single-ended signals, but CAN-H/L is differential signal, you cannot place it on the CAN lines.

Maybe consider the following ICs as a simpler solution:
https://www.ti.com/lit/ds/symlink/iso1044.pdf (CAN-PHY w/ Galvanic isolation, supply separation handled externally)
https://www.ti.com/lit/ds/symlink/isow1044.pdf (CAN-PHY w/ Galvanic isolation and supply separation)
 
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I have a CAN interface IC (ATA6563) between this IL514E and the CAN signals. So, we will be having single ended signals going to the IL514E IC. So, even if I use CAN-FD, this IC will support upto 2Mbps, right?
 

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FreshmanNewbie said:
I have a CAN interface IC (ATA6563) between this IL514E and the CAN signals. So, we will be having single ended signals going to the IL514E IC. So, even if I use CAN-FD, this IC will support upto 2Mbps, right?
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Yes, according Datasheet, IL514E will support up to 2Mbps. So it will limit your CAN-FD speed to this value.

But I still don't get the intend of using this IC.
For galvanic separation of CAN-IF, this IC is not enough, as you also need to separate VCC/GND. Therefore I suggested alternatives above.
For level shifting of RX/TX signals, it is unnecessary, as ATA6563 has separate VIO pin, so you can use 3V3 of the uC.
 

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