Ultra low-voltage/low-power digital floating-gate circuits

This paper describes a novel technique for implementing ultra low-voltage/low-power digital circuits. The effective threshold voltage seen from a control gate is adjusted during a UV-light-activated tuning procedure. The optimal effective threshold voltage matching the supply voltage and speed may be programmed by UV light through an activated conductance between the power rails and the floating gates. Measured results are provided for gates operating down to 0.4-V power supply, using a standard double-poly CMOS process.