LM3648: I2C signal Level

Kelly Wang

Part Number: LM3648
Other Parts Discussed in Thread: USB2ANY, , MSP-EXP430FR2311

I have a question about LM3648 I2C signal level. Data sheet says VIH min is 1.2V. when pulled up to 1.8V using 1.5k resistors, USB2ANY can't talk to LM3648 when not using USB2ANY pullup 3.3V. I am wondering whether I2C 1.8V level works for LM3648. Thanks.

4 months ago

0 Ives Li 4 months ago

TI__Expert 6440 points

Hi Kelly，

USB2ANY need to enable the 3V3 when using I2C，or the error will happen，so please use other interface adapter to test the 1.8V IO，and it is available for LM3648 .

Ives Li

0 Kelly Wang 4 months ago in reply to Ives Li

Prodigy 30 points

Ives,

Thank you for your reply. I tried launch pad MSP-EXP430FR2311 also. It does not work if pulled up to 1.8V.

0 Ives Li 4 months ago in reply to Kelly Wang

TI__Expert 6440 points

Hi Kelly，

Could you please provide the I2C signal waveform，so we can see if it caused by the pull up voltage.

Thanks！

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LM3648: I2C signal Level