DAC43204: I2C about DAC43204 and CG5162

Gary Teng

Part Number: DAC43204

Tool/software:

Hi Sir,

There's DAC43204 and CG5162 at the same I2C bus. Customer report that there's issue when they read CG5162's reg 0x20, there might have issue at its read byte: abnormal pull down happened at its bit 8 and only happened at reading 0x20. If they remove DAC43204, the issue is gone.

Normal waveform:

Issued waveform:

CG5162 has internal 4.7K pull up resistor, and cusomter add another 2K pull up resistor to 3.3V.

Do you have idea what's happened at the I2C communication at DAC43204? Any suggestion for checking the issue? Thanks for your kindly help.

Regards,

Gary Teng

4 days ago

0 Katlynne Jones 4 days ago

TI__Mastermind 32528 points

Hi Gary,

I can't find a datasheet for the CG5162. Can you confirm you are using I2C address 0x10 for CG5162? Looks to be 0x10 based on your screenshots. What I2C address are you using for the DAC43204?

What are some other registers that you read from the CG5162 that do not have issues with the DAC43204?

Best,

Katlynne Jones

0 Gary Teng 4 days ago in reply to Katlynne Jones

Genius 5520 points

Hi Katlynne,

CG5162's device address is 0x20. And customer said the issue is not relative with different DAC43204 address' setting.

And the issue is only happened when they readi 0x20 register.

Regards,

Gary

0 Katlynne Jones 4 days ago in reply to Gary Teng

TI__Mastermind 32528 points

Hi Gary,

The I2C address for CG5162 is 0x20? Are you including the R/W bit in the address?

Please share the details that I asked for in my last response:

What I2C address are you using for the DAC43204?

What are some other registers that you read from the CG5162 that do not have issues with the DAC43204?

It is important to know so I can think of some possible causes of the issue.

Best,

Katlynne Jones

0 Hector Chen 9 hours ago in reply to Katlynne Jones

Intellectual 340 points

Hi Katlynne,

Can the issue occur if the host reads data from the DAC and light sensor without ACK when receiving data?

Thanks

Hector

0 Katlynne Jones 43 minutes ago in reply to Hector Chen

TI__Mastermind 32528 points

Hi Hector,

If neither the DAC or light sensor ACK, then no device should be pulling the SDA line low.

Best,

Katlynne Jones

Because of the Thanksgiving holiday in the U.S., TI E2E™ design support forum responses may be delayed from November 25 through December 2. Thank you for your patience.

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DAC43204: I2C about DAC43204 and CG5162