Hi,
I am using the PCA9306-Q1 as an I2C switch using the switch enable control diagram found in the datasheet.
I wanted to know will there be any issues if I were to set both Vref1 and Vref2 to 3.3V. See the diagram below for ref.
I also noticed within different sections of the datasheet Vref2 is usually greater than Vref1. In my application, is this required? If not, when is it required to have Vref2 > Vref1?
Thank you,
Eric
Hi Eric,
Looking at the schematic you provided, it seems you are following the voltage translation configuration concerning the EN and Vref2 pins. I found this in the datasheet for the PCA9306 (non-Q variant):
Since you desire to use this device as an I2C switch, you need to follow the switch configuration as depicted in the datasheet below:
Where Vref1 = Vref2, and EN is controlled by a GPIO voltage that does not exceed Vref2 + Vth, where Vth is approximately 0.6V @ room temperature.
In your specific application, you do not need Vref2 > Vref1. This only applies when you want to use the Translation Configuration, where you operate two different I2C devices at different voltage levels.
Hope this helps,
Regards,
-Tyler
