PCA9306: Confirmation of applied circuits

Yamashita-san

Yuma Yamashita said:

Will a circuit like the one shown below work as a 1.2V to 3.3V I2C level shifter?
VCC_1R2_C is 1.2V
VCC_3R3V is 3.3V

The circuit looks correct for 1.2V to 3.3V I2C level shifting. 

Yuma Yamashita said:

First, is it OK to use this IC in multiple stages?
For example, can I convert 1.8V to 3.3V on one board and 3.3V to 5V on another board?

Yes the devices can be used in series to translate to multiple voltage levels. You must keep in mind that each PCA9306 added to the system adds bus capacitance which will affect the rise-time of the I2C system. 

PCA9306 is a passive level shifter device. The PU resistors on each side of the translator will appear in parallel since only a small RDS_ON resistance separates side 1 from side 2. This also means that the parasitic capacitance on side 1 also appears in parallel with the parasitic capacitance on side 2. 

Yuma Yamashita said:

Second, is there an input power sequence?
For example, should 3.3V be input before 1.2V input, etc.

No power sequencing requirements. 

Regards,

Tyler