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DS90UH949

Thomas%20Sagcob
Prodigy 70 points

Hello,

the values for VIH, VIL and VOL for I2C ports of DS90UH949Q1 are defined, acc.datasheet, by e.g. 0.7*VDDI2C....

Because of floating I2CSEL port, VDDI2C = 3V3 has been seleted.

But where is the supply pin @ DS90UH949 to plug in the 3V3?

For a WCCA I need the exact VIH, VIL & VOH values but I can't calculate because VDDI2C (incl. tolerances) isn't plugged in.

 

Regards
Thomas

  • 0
    TI__Mastermind 23810 points
    Thomas,

    I moved your post to the High Speed Interface forum. They should be able to help you here.

    Thanks,

    -Clancy
  • 0
    TI__Genius 13475 points
    The DS90UH949 has an I2C port which is 3V3 compliant - so you can use an use a pullup resistor to a 3.3V rail and have other 3.3V devices talking on the I2C bus. IN this case, VDDI2C is the rail which you have pulled the I2C pins up to, but this is not applied directly to the DS90UH949.
  • 0 in reply to Mark Sauerwald88474
    Prodigy 70 points
    Hi Mark, I know that the device is 3V3 tolerant. What I need to know for a WCCA are the device internal threshold voltages for VIH, VIL and VOH. Because these values are given in the datasheet with a relation to VDDIOI2C (e.g. VIH= 70%*VDDIOI2C) how can I calculate with these values if VDDIOI2C isn't supplied to the chip? IMO the threshold values have to be defined in an other manner. Can you please provide the threshold values for I2C and DDC bus so that I can complete the WCCA.