Implementation of active floating inductor based on second generation current conveyor for on chip voltage regulator

摘要

This paper presents a floating inductor implementation technique using active components. Floating inductor is an integral part of switching voltage regulator. Implementation of floating inductor is a primary bottleneck of on-chip implementation of switching regulator. In current CMOS circuit design, the implementation of the passive inductor is either external to the chip or fabricated as a part of the package. If it is incorporated within the chip, the passive inductor occupies very large chip area. In addition, passive inductors are not electrically tunable, which makes them unattractive for reconfigurable system-on-a-chip (SOC) designs. In contrast, an active device based floating inductor can be inserted within the chip. This new approach adapts the use of both positive and negative current conveyors. The proposed circuit allows the inductance value to be adjusted electronically by changing the bias current Io of the current conveyor. Design of the circuit is demonstrated using 0.5µm technology on Cadence Virtuoso with a +3.3V supply voltage. Simulation results are provided to verify the proposed design. Also, the design can be tuned further for nanoscale environment.