Hi,
This is my block diagram and has one issue.
When VDD2 is 3.3V, I2C operation is normal.
But, when VDD2 is 0V, SCL & SDA level of DAC7571 go down around 2.2V and I2C operation is abnormal.
As I know, I2C is BUS. So, SCL & SDA level should be 3.3V regardless VDD2 voltage.
When I remove DAC7571, SCL & SDA level is 3.3V and I2C operation is normal also.
Is there anybody who help me?
Thanks in advance.
Kevin