Patent ID: 7098394

Claim:
A power supply for powering a logic circuit, comprising: at least first and second photodiodes connected in series and integrated on a common substrate, said first photodiode having a first terminal and a second terminal, said second photodiode having a first terminal and a second terminal, wherein said first terminal of said first photodiode and said first terminal of said second photodiode are in electrical contact with the common substrate; wherein, upon illumination, the power supply generates a first potential difference between the second electrode of the first photodiode and the second electrode of the second photodiode, wherein the first potential difference is equal to 2*V T and is used to power the logic circuit; and wherein the first photodiode is a bipolar junction transistor having a collector that is shorted to a base; the collector and the base of the bipolar junction transistor are electrically connected to the common substrate, and V T corresponds to the voltage drop across the base-emitter junction of said bipolar junction transistor.