TCAN4551-Q1: Bit rate and SPI clock speed

Oba

Part Number: TCAN4551-Q1
Other Parts Discussed in Thread: TCAN4550

Hello,

I think max 18MHz SPI clock is recommended for 8Mbps data rate operation.
Do you have any data for how much bit rate can be realized with other SPI clock rate?
Do you have a kind of table that show CAN bit rate V.S SPI clock rate?

Regards,
Oba

over 3 years ago

0 Eric Schott1 over 3 years ago

TI__Guru 53535 points

Hi Oba,

I sent you an email with a tool that can be used to compare the throughput of the SPI and CAN interfaces for TCAN4550. Let me know if you have any questions while using it.

Regards,
Eric Schott

0 Oba over 3 years ago in reply to Eric Schott1

TI__Mastermind 18055 points

Hello Eric,

Thank you very much for seding the file.
It is helpful.

I have an additioanl qestion. The file shows actual datarate that can be achived by the selected SPI clock rate and CANFD datarate.
I just want to confirm if there is any limitation between SPI clock rate and CANFD datarate relationship.
For example, even if SPI clokc is 10MHz, can CANFD datarate be configured as 8Mbps? (I know lower SPI clock rate cause lower acutal datarate).
Can CANFD datarate be configured as 8Mbps regardless of any SPI clock rate?

Regards,
Oba

+1 Eric Hackett over 3 years ago in reply to Oba

TI__Guru 74992 points

Oba,

The CAN bus data rate is dependent on the input clock rate to the OSC1 and OSC2 pins, whether a crystal or a clock signal from a controller is being used. Having a slower SPI rate will just delay throughput due to SPI commands transmitting and receiving slower overall, but the actual CAN bus data rate will not be affected.

Regards,

Eric Hackett

0 Huan YANG over 3 years ago in reply to Eric Schott1

Intellectual 280 points

Could you share me also? Thanks a lot

huan.yang@zf.com

0 Eric Schott1 over 3 years ago in reply to Huan YANG

TI__Guru 53535 points

Hi Huan,

I have forwarded the document to you as well.

Regards,
Eric Schott

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TCAN4551-Q1: Bit rate and SPI clock speed