TCA9517A: VCCA > VCCB limts

Hey Steve,

"How much higher can VccA be than Vccb?"
-We typically tell our customers to stay to the recommendations set by TI and don't test outside these ranges so it's difficult for me to give a numerical answer to this. My recommendation is to just make sure VccB stays above 2.7V (datasheet spec) and be aware when VccA goes above VccB the device is no longer following recommended settings and may not meet datasheet spec. Small voltage deviations likely won't damage this device.

"Both supplies are nominally 3.3V but one could be +5% and the other at -5%. Will this allow the TCA9517A to work properly?"
5% on both sides does not seem like a huge difference to me. This will change the voltages this device references (internally) to the comparators by a small amount that it likely won't make a difference. If the slave/master are also tied to the same voltage rails then ViL and ViH for the devices will scale by the 5% swing as well.

Thanks,
-Bobby