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TMP1075: I2C Signal

Part Number: TMP1075

Dear Team,

It seems the I2C signal Clock Pulse Width Low fail, as we measure 1.2us

Do you have any ideas why?

BR

Kevin

  • Hi Kevin,

    Thank you for your post, and for including the schematic and scope captures. This specification in the datasheet is taken directly from the I2C fast mode spec. The SCL low time is a specification for the I2C master to meet, since SCL is master controlled. The TMP1075 does not control this. They will have to change the duty cycle for SCL within the code for their I2C Master. 

    Looking at the schematic, is there a reason that they have those 39pF capacitors on their SDA and SCL lines? I2C has a 400pF limit for bus capacitance, by including these they are cutting that down by about 120pF. 

    Please let me know if you have any additional questions. 

    Best Regards,
    Brandon Fisher