TCAN1043A-Q1: CM choke value

ABKD

Intellectual 300 points

Part Number: TCAN1043A-Q1
Other Parts Discussed in Thread: TCAN1043-Q1

Tool/software:

Hello,

For 2 Mbps operation of CAN transceiver TCAN1043-Q1, how to select the inductance value of common choke?

4 months ago

0 Sean Guo 4 months ago

TI__Mastermind 27780 points

Hi ABKD,

The recommended value for CAN applications is 51 to 100 uH. Our EMC test report use 100 uH.

Regards,

Sean

0 ABKD 4 months ago in reply to Sean Guo

Intellectual 300 points

Thanks Sean.

But, if CAN data rate is 500 Kbps or 8 Mbps (for CAN FD), still we have to use 51uH to 100uH ?

Or need to change the inductance for higher data rate?

+1 Clemens Ladisch 4 months ago in reply to ABKD

Guru 316760 points

Common-mode chokes filter out common-mode noise, but have a low impedance for differential (data) signals. Check the datasheet for the differential impedance at the signal frequencies, but in general, this is not a problem at all.

0 ABKD 4 months ago in reply to Sean Guo

Intellectual 300 points

Hello Sean / Clemens,

Does this inductance value of 51uH to 100uH arrived from testing?

0 Clemens Ladisch 4 months ago in reply to ABKD

Guru 316760 points

It depends on the amount of common-mode noise that you expect to encounter in your actual environment. If you say "I don't know", then those values are commonly used.

0 Sean Guo 4 months ago in reply to ABKD

TI__Mastermind 27780 points

Yes as Clemens said for most vehicle environment this value will be enough. It's a common value used by OEMs/ third party test house.

Regards,

Sean

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TCAN1043A-Q1: CM choke value