5 I²C Voltage Translation

While TI’s I²C buffers/repeaters offer level shifting for master and slave voltage mismatches, TI also offers level shifting on the I²C bus if buffering is not needed. PCA9306 and TCA9406 are two devices in TI’s portfolio that offer level shifting. The internal structure of both devices is similar to that of a switch which allows the bidirectional open-drain bus to pass through while level-shifting to ensure proper communication through I²C. The operation of the I²C level-shifting is the same as the voltage translation performed by I²C buffers/repeaters.

Figure 11. Operation of an I²C Voltage Translator/Level Shifter