Classification of auxiliary circuit schemes for feeding fast load transients in switching power supplies

This paper presents a systematic classification of auxiliary circuit schemes for feeding fast load transients in switching power converters. The classification is based on the types of the implementation methods, practical constraints and performance. In particular, auxiliary circuits are classified according to the ways in which they are connected with the power supplies and loads, as well as the choice of control methods. Designed as a shunt output, the 'intruding' type of auxiliary circuits is effective and less dissipative. Moreover, to reduce complexity, auxiliary circuits may be designed in the form of a bridge output, and employs a 'non-intruding' type of control scheme. Furthermore, provision of pre-informed loading condition leads to further simplification of auxiliary circuitry and improvement of efficiency. Experimental measurements are provided to support the analysis of the properties of various types of circuits.