Chagrin:
The PCA9544 or PCA9548 state that they both include level translation; the PCA9306 wouldn't be needed. Not sure I understand the doc's instructions on how to set that though.
I had the same problem to understand this. It briefly says that they both include level translation, but they don't say more than this.
The I2C voltage level translator that we are talking above, needs to have the 5V side as well as the 3.3V side like PCA9306. However, the PCA9544 and the PCA9548 don't have them. Then we need to add the PCA9306 in order to do the voltage-level translation...?