LMK03328: I2C pull-ups with no power supplying

Takayuki Yasukawa

Part Number: LMK03328

Tool/software:

Hi support team,

Can I connect the I2C lines (SDA, SCL) of LMK03328 through pull-ups to a different power net than VDD_DIG when LMK03328 is no power supplied?

According to section 8.1 of the datasheet, the Abs Max of SDA(#25) and SCL(#26) are 3.6V, which can be read as being independent of own VDD.

Is my understanding correct?

A further question: is there any problem with I2C access to devices at other slave addresses when that power is not supplied?

Best regards,

9 months ago

0 Cris Kobierowski 9 months ago

TI__Expert 4545 points

Hello,

1. Yes you can have the pull-ups go to a different power net, as long as the I2C lines are pulled up to 3.3V.

2. If the LMK03328 does not have power supplied, there should be no issue accessing other devices at other slave addresses, assuming those devices do have proper power supplied.

Best,

Cris

0 Takayuki Yasukawa 8 months ago in reply to Cris Kobierowski

Prodigy 30 points

Sorry, I have one additional question.

>1. Yes you can have the pull-ups go to a different power net, as long as the I2C lines are pulled up to 3.3V.

I want the I2C lines to be pulled up at 1.8V, but does it need to be 3.3V?

0 Cris Kobierowski 8 months ago in reply to Takayuki Yasukawa

TI__Expert 4545 points

Hello,

I2C lines need pullups to 3.3V

Best,

Cris

0 Takayuki Yasukawa 8 months ago in reply to Cris Kobierowski

Prodigy 30 points

Hi, thank you for your reply. I understood.

Thanks,

Clock & timing

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LMK03328: I2C pull-ups with no power supplying