Designing with PCA9545AD,118

[shibin]

Hi Team,
We want to use PCA9545AD,118 in one of our designs.
We have 3 pressure sensors of the same I2C address.
Only a single I2C bus is available, so I am planning to use an I2C address switch like PCA9545AD,118.
1). In the datasheet, it is specified that we can pull up all the interrupt input pins if they are not in use. So, can I leave my interrupt output pin floating?.
2). The fourth I2C channel is not used, so can I leave all those pins floating, or do I need proper pullup terminations for that?.
Both sides of the chip use 4.7K resistors on their I2C lines.

[JozefKozon]

Hi Shibin,

For unused pins, we generally follow rules below:
1. Output pin: floating it.
2. Input pin: pull it up to HIGH with 10k resistor
3. I/O bidirectional pin: pull it up to HIGH with 10k resistor
This design method can improve EMC performance.
Therefore, you can refer to this method to handle those unused pins!

1). In the datasheet, it is specified that we can pull up all the interrupt input pins if they are not in use. So, can I leave my interrupt output pin floating?.

[A] Yes, the output interrupt pin can/should be left floating.

2). The fourth I2C channel is not used, so can I leave all those pins floating, or do I need proper pullup terminations for that?.

[A] The SDx and SCx lines are I/O bidirectional pins. Please pull the unused SDx and SCx pins high with 10k resistors.

With Best Regards,

Jozef