LCMOS, a harvest-use light-powered scheme for standard CMOS circuits based on photogenerated currents in the drain-substrate PN junction of both PMOS and NMOS transistors is introduced. PMOS and NMOS bulks are groundconnected so the generated currents induce symmetrical positive and negative voltage at the PMOS and NMOS sources, respectively. Applying this approach to a CMOS inverter ring oscillator in 150 nm technology, simulations show that nearly 1 Vpp signal range can be obtained. The operation of a simple 4- bit counter is also illustrated. The light-powering technique can be applied almost directly to digital standard cells in ultra-lowpower applications with modest processing speed requirements.