Constant-Frecuency Limiter for a Sliding Mode Control

Abstract

The conmutation frequency in a Sliding Mode Control (SMC) for dc-dc converter is affected by main voltage and load variations. This problem is undesirable for L and C component design. To maintain a constant-switching frequency under variations in load and main voltage, a constantfrequency limiter based on microcontroller isproposed. This limiter is very simple and must be implemented in any type of microcontroller. Experimental results are showed usind a Buck converter with sliding mode control sensing the output current.