DAC43608: No output issue

Yusuke Mukuno

Part Number: DAC43608

Hi Expert,

My customer have an issue about no output when the Vcc ramp up speed is fast. (POR is abnormal condition???)

They set output voltage registers by I2C. Then, they confirm to receive ALK signal. (They think, I2C communication is normal.)

However, Vout did not reflect the output settings.

If Power-on-Reset is fail, is it possible that Vout will not be output? (the I2C interface work normally)

They use SW_RST, then they wait few time. After that, they set the registers by I2C. >> This issue was solved.

Does LM43608 have the specification(or your recommendation) for the wait time between SW_RST and I2C communication?

Thanks

Muk

over 4 years ago

0 Uttam Sahu over 4 years ago

TI__Genius 14220 points

Hi Yusuke,

Thanks for reaching out. Let me check with the internal team and get back on this.

Regards,

Uttam Sahu

applications Engineer, Precision DAC

0 Yusuke Mukuno over 4 years ago in reply to Uttam Sahu

TI__Expert 7395 points

Hi Sahu-san,

Do you have any update?

Muk

0 Uttam Sahu over 4 years ago in reply to Yusuke Mukuno

TI__Genius 14220 points

Hi Yusuke-san,

Apologies for the late response. The SW_RST to I2C delay is around 15ms.

Hope that answers your question.

Regards,

Uttam

0 Yusuke Mukuno over 4 years ago in reply to Uttam Sahu

TI__Expert 7395 points

Hi Uttam-san,

Thank you for your answer!

Is there a possibility that the following phenomenon will occur?

-----

They set output voltage registers by I2C. Then, they confirm to receive ALK signal. (They think, I2C communication is normal.)

However, Vout did not reflect the output settings.

If Power-on-Reset is fail, is it possible that Vout will not be output? (the I2C interface work normally)

-----

Thanks

Muk

0 Uttam Sahu over 4 years ago in reply to Yusuke Mukuno

TI__Genius 14220 points

Hi Mukuno-san,

In POR, there are defined states and undefined states. In defined states, the POR is either activated or not activated and the device behavior is known. However, in an undefined state, the behavior is unknown. You can see the specifications of different POR states in figure 55 in the datasheet.

In order to get a predictable behavior, we would recommend waiting for the specified time after a reset event. In case of a power glitch, it is better to take the device through a proper POR.

Regards,

Uttam

0 Yusuke Mukuno over 4 years ago in reply to Uttam Sahu

TI__Expert 7395 points

Thank you very much

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DAC43608: No output issue