ISO1640: Bidirectional isolator for 4 channels

Dejan Hrovatin1

Part Number: ISO1640

Tool/software:

Hello,

I'm working with bidirectional communication (0-3.3 V), so communication over one wire can go in both ways. I have to isolate 4 channels, so four wires with bidirectional communication. Is there any isolator for 4 channels that you can suggest it? Usually there are isolators for one way communications.
Would be ISO1640 an appropriate one? I know that I need to use two of them to isolate 4 channels, but the problem I see with this isolator is offset on the Side 1. It would be great to don't have it, but I understand that this isolator was developed to isolate I2C communication lines.

Many thanks,
Kind regards,
Dejan.

over 1 year ago

0 Clemens Ladisch over 1 year ago

Guru 317260 points

Bidirectional isolation is possible only if the isolator knows in which direction it should propagate the signals. In the case of I²C, low signals have priority over high signals.

What protocol are you using?

0 Dejan Hrovatin1 over 1 year ago in reply to Clemens Ladisch

Intellectual 380 points

Hello Clemens,

I'm talking about DShot protocol. Protocol is not very known, however, here is some documentation: https://brushlesswhoop.com/dshot-and-bidirectional-dshot/

Many thanks, Dejan.

+1 Andrew J over 1 year ago in reply to Dejan Hrovatin1

TI__Mastermind 29375 points

Hello Dejan,

ISO1640 is likely the best option for you. The side 1 offset is common and necessary in bidirectional isolators since they prevent a bus latch-up condition ((+) [FAQ] Why is the logic LOW level output voltage, VOL1, up to 0.8V on Side1 of the ISO1540/ISO1541 and ISO1640/ISO1641 bidirectional I2C isolators?).

The link in your previous post is blocked for me, but from the limited information I can find on the protocol I am expecting the physical layer to be I2C-like. The ISO164x family will pass the signal from open-collector I/O's and it should work well for the application.

Best,
Andrew

Isolation

Isolation forum

ISO1640: Bidirectional isolator for 4 channels