TUSB8043A: SMBus clock speed

Yuta Nishie

Part Number: TUSB8043A
Other Parts Discussed in Thread: TUSB8043

HI,

Regarding TUSB4043A, should I set the SMBus clock speed to 400kHz?

If I2C is only tested up to 400kHz, is it correct to understand that it is not guaranteed to run the SMBus at a higher clock speed?

Best Regards,

Nishie

+1 Brian Zhou 1 month ago

Hi Nishie:

it is not guaranteed to run the SMBus higher than 400khz.

Best

Brian

0 Yuta Nishie 1 month ago in reply to Brian Zhou

Genius 5750 points

Hi Brian-san,

Thank you for your support.

I understand the bus speed of SMBus as follows, is it correct?

100kHz: operation OK

400kHz: operation OK (for 400 kHz or less)

401kHz <=: operation not guaranteed

Best Regards,

Nishie

+1 Brian Zhou 1 month ago in reply to Yuta Nishie

your comments are correct.

Best

Brian

0 Yuta Nishie 1 month ago in reply to Brian Zhou

Genius 5750 points

Hi Brian-san,

Sorry. I have a follow-up question.

I found the following thread, which says ”You can only read vendor ID in SMBUS mode ( SMBUSZ is low), CLK frequency is 100kHz ."

Your answer says "400kHz operation is OK," but which is actually correct?

Best Regards,

Nishie

+1 Brian Zhou 1 month ago in reply to Yuta Nishie

TUSB8043 can support both standard I2C mode (100kHz) and fast mode (400khz).

Regards

brian