Nonlinear Current Control for Power Electronic Converters: IC Design Aspects and Implementation

This letter provides design guidelines and presents a fully integrated implementation of the recently proposed nonlinear average current control (NACC) algorithm for power factor correction and dc-dc converters. The control performance and dynamics of the current-mode controlled power electronic converter strongly depends on the accuracy of the applied current sensing method. Several current sensing methods have been proposed in the literature, including the senseFET method, which is suitable for on-chip current measurement. This letter presents a modification of the senseFET on-chip current sensing technique dedicated for an ultrahigh sensing ratio and suited for the current sensing processing, which gives current-type output what fits well with the NACC control method, thus further simplifying the converter design and reducing cost as well as noise sensitivity of the control circuitry. Hence, the need for a voltage-to-current and current-to-voltage transformation circuit is eliminated. Therefore, the proposed method of the current sensing is applicable to any boost-like converter, whose control system requires an extremely high sensing ratio to be achieved. Nevertheless, it is especially well suited to be combined with an NACC control circuitry irrespective of the required sensing ratio. Experimental results verify the proposed design done in 0.35-μm HV triple-well CMOS technology.