±0.25-V Class-AB CMOS Capacitance multiplier and precision rectifiers

Reducing the minimum supply requirements plays a vital role in minimizing power consumption in VLSI systems. This article presents a highly efficient capacitance multiplier that can operate with supplies as low as ±0.25 V. The design is centred around adaptively biased class-AB current mirrors, which offer excellent current efficiency. Experimental measurements conducted on a capacitance multiplier with a factor of 11, fabricated using 180-nm CMOS technology, validate the theoretical claims. Additionally, the same class-AB current mirrors are employed in the design and fabrication of low-voltage precision rectifiers using the same CMOS process. These rectifiers generate output currents over 100 times greater than the quiescent current. Both circuits proposed in this study exhibit a static power dissipation of only 300 nW when operating with ±0.25 V supplies.

Keywords: —— Capacitance multiplier, class-AB current mirror, low supply voltage, precision rectifiers.