ISO1050: placement of common mode choke in ISO1050

Zhonghui Xu

Part Number: ISO1050
Other Parts Discussed in Thread: ISO1044DEVM, ISO1042DWVEVM

Hi team,

I got a question from customer.

We have introduce CMC in our design as recommended. now we have query regarding the placement of Common mode choke On PCB ..

Could you please help us where to place Common mode choke .? Should we place Common mode choke near to IC ISO1050 or near to protection circuitry and resistors (R122,R123).(Please suggest the Placement )

Thank you very much for your help.

Best regards,

over 2 years ago

0 Manuel Chavez over 2 years ago

TI__Genius 17100 points

Hi Zhonghui,

Thank you for posting to E2E and sharing our customer's schematic. We demonstrate the recommend layout for our isolated CAN devices, including provisions for a CMC and protection components, in our newer evaluation modules, like the ISO1044DEVM and ISO1042DWVEVM. Similar placement of components can be copied for ISO1050. We recommend the CMC is placed closest to the isolated CAN device, followed by the termination elements, and the protection diodes should be placed as close as possible to the connector on the PCB.

Schematic and PCB images of the ISO1042DWVEVM are shown below for reference. Note that some of the components in the schematic are not actually populated on the PCB but included in the schematic to demonstrate different configuration options:

Please let us know if you or our customer have any additional questions.

Respectfully,
Manuel Chavez