BQ25629: BQ25629 Custom PCB: False I2C response

Hi, 

We have a custom PCB which follows a similar schematic in the EVM board mentioned in this: https://www.ti.com/lit/ug/sluucq9/sluucq9.pdf?ts=1705993731348

Current status of the battery charger:

• The charger IC functions partially
• It is capable of charging our Li Ion battery with default configs
• Switching between battery and USB charger works properly
• The device responds with an acknowledgement when requested via I2C but the IC responds 0x00 for all requested registers. This was observed using a logic analyzer and the sample waveform is below. I2C bus is working at 100Kbps

• The I2C waveforms were observed via an Oscilloscope to see for its signal integrity, the state switches are fine. Please check the image below. 

SCL

SDA

• There are other I2C slaves connected to the same rail, following are a list of them with their status
  • BQ25629 - No communication
  • BQ27427 - No communication
  • LP5813 - Functions properly
• We send communication commands 2 seconds after booting up
• We have a BQ25629EVM module with us for comparison and it communicates properly.

Questions & Requests

• Any idea why the IC does not respond properly?
• Is it possible for you to provide us a sample firmware? 

Thank you and will be waiting for a response.

Sincerely,
Chamith Koperahewa