A 1μA linear regulator with programmable NMOS pass device

A low power linear regulator architecture implemented with floating-gate transistors is presented. The proposed circuit allows for a bandgap-less implementation, output voltage modification and circuit performance improvement after fabrication. A floating-gate nMOS pass transistor was adopted for threshold modification. The proposed approach increases the overdrive voltage of the pass device without the need of charge pumps or refreshing floating capacitor, hence drop-out voltage reduction can be obtained with no additional power consumption. Prototypes fabricated in 0.5μm CMOS process operate with 1μA of quiescent current and minimum supply of 1.8V. Experimental results show output voltage programmability from 0.8V to 1.4V, maximum load of 1mA, line regulation of 4.7mV/V, load regulation of 45mV/mA, and a maximum temperature coefficient of 60.2ppm/°C.