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PCA9544A: PCA9544APWR

Lisa George
Prodigy 90 points
Part Number: PCA9544A

Currently we are using the PCA9544APWR Mux for our project. There is a concern regarding the supply voltage Vcc. All the SMBus lines are pulled up to 3.3V. So can the supply voltage Vcc be 3.3V? From the graph 9.2 in the part datasheet the Vcc value corresponding to a Vpass of 3.3V is 4.5V. Will the IC work with the 3.3V supply voltage.

pca9544a.pdf

  • +1
    Guru 272840 points

    Using a 3.3 V supply will work.

    I²C uses open-drain signals, i.e., the high signal level is generated by the pull-up resistors. So the switch is not required to pass through high voltages. (If the switch did allow voltages near the supply to pass through, level shifting would not be possible.)