select Rbus versus Cbus Value (M24M01)

[yjin.1]

Hi,

I'm trying to develop using the M24M01 product. There is a part in DATASHEET that I don't understand, so I leave a question.

In the item 'Maximum Rbus value versus bus parasitic capacitance Cbus', it is stated that the Rbus X Cbus value should come into the below time line. But if the cbus value or rbus value is too small,(ex. Rbus X Cbus = 10ns for 1kohm, 10pF) What could be the problem? 

In addition, a pull-up resistor is not required on the SCL line? (Not in DATASHEET)

[Pierre P.]

Hello,

No problem with low R x C bus. Moreover, it depends on the frequency the application operates. ( To High RxC bus will not allow 1MHz frequency )

About the pull-up resistor on SCL, ST doesn't recommend to put a pull-up resistor (even if I2C spec UM10204 does).

The application note AN2014 available on ST.COM will help you on this point. (https://www.st.com/resource/en/application_note/cd00042024-how-a-designer-can-make-the-most-of-stmicroelectronics-serial-eeproms-stmicroelectronics.pdf)

BR

Team EEPROM suPPort

[yjin.1]

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[yjin.1]

Hi,

Thank you for your quick reply. I have an additional question.

You said that the low R X C bus has no problem. I also checked the Application note "AN2014".

Then how about not having Cbus at all? Isn't that any problem?

I look forward to your reply.

Thanks.