TPS55289: Inquiries that NACK occurs in I2C communication of TPS55289

Kim JaeHyung

Part Number: TPS55289

Tool/software:

Hi, dear,

I have now built a regulator with an input voltage of 12V and an output voltage of 10V using TPS55289.

I tried I2C communication to set the 10V output, but the NACK signal kept getting feedback.

I want to know why.

best regards.

0 Bryce Xun 10 months ago

Hi Kim,

Have you checked the EN, VCC voltage of TPS55289?

From the waveforms, I don't think the I2C address is 75H. Please double check about this.

BRs,

Bryce

0 Kim JaeHyung 10 months ago in reply to Bryce Xun

Dear, Bryce Xun,

I measured the place you mentioned again.

It still outputs NACK.

1. EN/UVLO (PIN 1) measured at 3.3 V.
2. VCC (PIN 18) is measured at 5.27 V.

3. Address waveform :0x75

jaehyung kim,

0 Kim JaeHyung 10 months ago in reply to Bryce Xun

Dear, Bryce Xun,

Problem solved.
I didn't know I had to shift 1bit to the left.

Thanks alot.

jaehyung kim,

0 Mulin Yuan 10 months ago in reply to Kim JaeHyung

Hi Kim,

Glad to hear that. I will close this thread. Feel free to reply if you have more question and it will open again.

Regards,

Mulin

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