I want to switch the supply power of a low current high frequency load between 3V and 1.8V using a microcontroller. They are powering a CPLD IO-bank that I use as a level translator. Current consumption will be 20mA peak.
I already have the two voltages from regulators to power other things, so I want I really want is to multiplex between the two supplies I guess.
Is there an easy way to switch between the two supplies using one or two GPIO-pins? I need fairly low impedance switching and I can't tolerate any voltage drop.
Best Answer
You could put a pfet between the supply's and the Vio pin on the CPLD. Just make sure you only turn one on at a time. Does the CPLD not have multiple Vio banks? Because as soon as you flip the the higher voltage, everything will see it. Can all the translated devices stand that voltage?