Constant-Frecuency Limiter for a Sliding Mode Control

Abstract

The commutation 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 constant-frequency limiter based on microcontroller is proposed. This limiter is very simple and must be implemented in any type of microcontroller. Experimental results are showed using a buck converter with sliding mode control sensing the output current