Tool/software:
HI TI Teams
How can I verify the relationship between Vref2 and the pull-up voltage on the PCA9306? In my system, SDA1 and SCL1 are at 1.8V, while the other side is at 3.3V. However, after removing the pull-up resistors to 3.3V, SDA2/SCL2 still outputs a voltage of 2.8V.
Could you provide the internal design related to the EN pin, SCL2 pin, and SW, so that we can understand the relationship between VREF and the output voltage?
It is not clear from this image.
The PCA9306 is identical with the LSF0102; see [FAQ] How do the LSF translators work?
The circuit at the EN/Vref_B pins ensures that the gate voltage of all transistors is Vref_A plus the threshold voltage. This means that for all voltages between 0 V and Vref_A, the switch is closed, and behaves like an analog switch, i.e., the voltages at the Ax and Bx are about the same. This means that voltages below Vref_A are not translated. (For voltages above Vref_A, the switch is open, and the high-level voltage is determined by the pull-up resistors.)
