An area efficient on-chip hybrid voltage regulator

Experimental results of an active filter based on-chip hybrid voltage converter are described in this paper. The area of the voltage converter is significantly less than the area of a conventional passive filter based DC-DC voltage converter or a low-dropout (LDO) regulator. Hence, the proposed circuit is appropriate for point-of-load voltage regulation for the noise sensitive portions of an integrated circuit. The performance of the circuit has been verified with Cadence Spectre simulations and fabricated with a commercial 110 nm CMOS technology. The area of the voltage regulator is 0.015 mm2 and delivers up to 80 mA of output current. The transient response with no output capacitor ranges from 72 ns to 192 ns. The advantages and disadvantages of an active filter based, conventional switching, linear, and switched capacitor voltage converters are compared. The proposed circuit provides a means for distributing multiple local power supplies across an integrated circuit while maintaining high current efficiency and fast response time within a small area.