Modeling of current-programmed converters with inductor current sensing

The switching regulator uses the buck, boost and buck-boost switch-mode converters as the power stage. A general small-signal model for the switching power stage is derived, this shows the inductor current. These converters have high quality factors due to a LC filter. A scheme, often used, is to provide high damping using an inner loop. The resulting characteristics for the current-programmed converter, operating in continuos conduction mode, are discussed in this paper. The interest in these models is clearly motivated by the need to have simple expressions for switch-mode DC-DC converters that are easy to apply for design-oriented analysis. At the end, the procedure is illustrated for a 280 W boost regulator that shows the simplicity of the expressions.