5V CBT device using 3.3V I/O

Hi Kenshow,

The device will work with 3.3V on the IO pins, but it will require at least 4.3V on the supply pin.  You can see the trigger voltage levels (Vih and Vil) in the Recommended Operating Conditions -- they indicate that a 'high' voltage is at least 2V on the control pins, so 3.3V would work fine.  As for the voltage passed through the IO pins, you can see a plot of Vo to Vin under Figure 4 on the datasheet.  Basically it just shows that the device can only pass voltages about 1V less than the supply voltage.  If you are supplying 5V, you shouldn't have any problems.

It's important to note that this device draws very little power through Vcc to operate (~10uA max), so a charge pump would work perfectly to give you a 5V supply if you don't have one available already.