Analysis of self-resonant frequency for differential-driven symmetric and single-ended inductors

In this paper, a distributed capacitance model (DCM) for monolithic inductors is developed to predict the equivalent parasitical capacitances of inductor. The ratio of the self-resonant frequency (f_SR) of the differentially driven symmetric inductor (f_{SR_diff}) to the f_SR of the single-ended driven inductor (f_{SR_se}) has firstly predicted and explained. Compared with an equivalent single-ended configuration, experimental data demonstrate that the differential inductor offers a 127% greater maximum quality factor (Q_max) and a broader range of operating frequencies. Design guidelines have been obtained from DCM.