A function cell comprising a first field effect transistor (FET) device, a second FET device, a first node connected to a gate terminal of the first FET device and a gate terminal of the second FET device, wherein the first node is operative to receive a voltage signal from an alternating current (AC) voltage source, an amplifier portion connected to the first FET device and the second FET device, the amplifier portion operative to receive a signal from the first FET device and the second FET device, a phase comparator portion having a first input terminal connected to an output terminal of the amplifier and a second input terminal operative to receive the voltage signal from the AC voltage source, the phase comparator portion operative to output a voltage indicative of a bit of a binary value.