PCA9306: For PCA9306, can Vref1 equals Vref2?

Hi Nic,

Yes, the device can be used this way. This allows for the EN pin to be used to either enable or disable certain segments of an I2C bus. You can refer to this thread for more details:

e2e.ti.com/.../495150

For the most part I would not expect this operation to result in significantly different performance, although it should be noted that the propagation delays will be lengthened somewhat. This device typically uses the VREF2 supply to bias the gates of the internal pass elements slightly higher than VREF1 in order to achieve fast turn-on during a falling edge. If the two voltages are equal, the conduction between both sides will not occur until the SDA/SCL voltage drops by ~0.6 V.

Please let us know if you have any further questions.

Regards,
Max