TPS23882: NACK issue of I2C interface

Jeffrey Chung1

Part Number: TPS23882
Other Parts Discussed in Thread: USB2ANY

Hi,

I'd like to ask you about NACK issue of I2C interface. There are the schematic of this chip and waveform of I2C interface in attached file below. Please let me know how to fix it, and refer to the attached file.

TPS23882RTQT.pdf

Regards,

over 4 years ago

0 Darwin Fernandez over 4 years ago

TI__Mastermind 41760 points

Hi Jeffrey,

This is currently being looked into. An answer will be posted when available. Thanks!

0 Jeffrey Chung1 over 4 years ago in reply to Darwin Fernandez

Genius 3280 points

Hi Darwin,

Thanks for your support. I hope that you post your answer as soon as possible. I'll wait for your response. Please let me know if you need the additional information about this issue.

Regards,

0 Penny Xu over 4 years ago in reply to Jeffrey Chung1

TI__Genius 15685 points

Hi Jeffery,

Can you capture a waveform including VPWR, VDD and RESET during power on? And is there any isolators between the host and TPS23882 for the I2C bus? Thanks.

Best regards,

Penny

0 Jeffrey Chung1 over 4 years ago in reply to Penny Xu

Genius 3280 points

Hi Penny,

Waveform including VDD, VPWR, RESET is attached below. There is no isolator between the host and TPS23882 on I2C bus. Please refer to the attached file.

Waveform of VDD, VPWR, RESET.pdf

Regards,

0 Penny Xu over 4 years ago in reply to Jeffrey Chung1

TI__Genius 15685 points

Hi Jeffery,

The blue trace is 1V/div which makes sense, but why the red trace (Vpwr) is 5V/div? I can't read the Vpwr correctly.

To isolate the problem, can you disconnect the I2C lines from the host and use USB2ANY and USB2ANY explorer to check if you can communicate with TPS23882 device? Thanks.

Best regards,

Penny

0 Jeffrey Chung1 over 4 years ago in reply to Penny Xu

Genius 3280 points

Hi Penny,

The voltage division of VPWR is 5V/div because it is a high voltage of 12V. And my customer has not the USB2ANY interface adapter, so can not check it through USB2ANY explorer. Is there any other check point to resolve this issue? Please let me know that.

Regards,

0 Penny Xu over 4 years ago in reply to Jeffrey Chung1

TI__Genius 15685 points

Hi Jeffrey,

I didn't quite understand this: The voltage division of VPWR is 5V/div because it is a high voltage of 12V. We should expect to see 44V to 57V on Vpwr. If the voltage on VPWR is only 12V, the device will not be functional. Please make sure the VPWR voltage is correct. If you still see the I2C issue after fixing the VPWR issue, please order a USB2ANY adapter for your customer and do the test I mentioned above. Thanks.

Best regards,

Penny

0 Jeffrey Chung1 over 4 years ago in reply to Penny Xu

Genius 3280 points

Hi Penny,

I did already know that supply voltage range of VPWR is 44V to 57V. This condition is just for testing of I2C bus only. As you told me on previous post, I will order USB2ANY adapter for testing of my customer. Is there any other check point to resolve this issue until USB2ANY adapter is arrived?

Regards,

0 Penny Xu over 4 years ago in reply to Jeffrey Chung1

TI__Genius 15685 points

Hi Jeffrey,

As I said before, you have to increase the VPWR voltage to 44V ~57V first. 12V is not going to work as the device is not fully powered. Even you have USB2ANY and USB2ANY explorer, the I2C will not be working with 12V on VPWR. Thanks.

Best regards,

Penny

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TPS23882: NACK issue of I2C interface