Integrated Circuit of CMOS DC-DC Buck Converter With Differential Active Inductor
In this paper, the authors propose a new design of DC-DC Buck Converter (BC), which the spiral inductor is replaced by a differential gyrator with capacitor load (gyrator-C) implemented in 0.18um CMOS process. The gyrator-C transforms the capacitor load (which is the parasitic capacitor of MOSFETS) to differential active inductor DAI. The low-Q value of DAI at switching frequency of converter (few hundred kHz) is boosted by adding a Negative Impedance Converter (NIC). The transistor parameters of DAI and NIC can be properly chosen to achieve the desirable value of equivalent inductance L (few tens Î¼H), and the maximum-Q value at the switching frequency, and thus the efficiency of converter is improved.