PCA9306: Input on valid power down conditions of PCA9306 as isolator for I2C slave

user5865193

Part Number: PCA9306

Hi,

I am interested in using the PCA9306 (assuming that this is indeed my best option) to isolate an I2C bus from an I2C slave. I'm designing a low-power system where I want to be able to individually isolate and power down various sensor nodes that are not in use. I would like to confirm whether it is ok or not to hook the EN signal of PCA9306 to the SLAVE VDD and then power down the entire slave supply. When the slave is enabled, the voltage levels on each side of PCA9306 will be the same. See figure:

Does this seem ok to do?

Thanks!

over 7 years ago

0 Miguel Robertson over 7 years ago

TI__Guru 62920 points

Hello,

Yes, it is ok to use PCA9306 in this manner (i.e. as a means of disabling bus segments rather than as a voltage translator). When the EN pin voltage drops to 0 V, the device's internal switches will be high impedance and block I2C from propagating.

Regards,
Max

0 user5865193 over 7 years ago in reply to Miguel Robertson

Prodigy 20 points

Sweet, thanks!

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PCA9306: Input on valid power down conditions of PCA9306 as isolator for I2C slave