MP5515 IIC no response

it hadn’t returned ACK when I access 0x33 by IIC. It happened occasionally.


  1. We have produced thousands of products, but this problem occurs with less than 10 products.
  2. On the product with the problem, there is about a 40% probability that IIC will not respond.
  3. When the problem occurred, the other IIC devices were normally but MP5515(0X33) had no response.

Hello, Bluesky
What the pull up voltage for both SCL and SDA? It seems <1.8V or ~1.8V in your waveform.
And we observed NA at the 9th clock (SCL logic high).

Hi, Daniel.Yang,
The pull-up voltage is 1.8V.

Hello, Bluesky

Could you have a test with 3.3V on these parts?

The min pull-up voltage in the datasheet is 1.2V. Do you find this issue in other cases in which the pull-up voltage is 1.8V?

I want to learn more about your schematic, such as the pull up resistor. We have specification on the
rise time and fall time of SCL SDA. BTW, can we have a conversation in email?

Yes, Could you leave your email address? I will show you the relevant information.

How about the follow-up feedback from customer?

We used IC batches in 2017, it’s a known problem with IIC hang. New batches are no problem.

Thank you! Noted! :grinning: :grinning: