Comparative analysis of PWM/PFM controlled SMPS using Matlab Simulink

The design of PWM/PFM controller for SMPS is explained in this paper. An application concerning logic controller to manage is given. controller used here is Pulse frequency modulation (PFM)and pulse width modulation(PWM). In general for light load pulse width modulated buck converter operates with high efficiency since it has less switching losses, for heavy load operation pulse frequency modulation buck converter operates with less losses. Discontinuous conduction mode of pulse frequency modulated buck converter is considered in this paper for its concert in an application connecting a source with unstable voltage conditions with a load which requires constant voltage. Here, the pulses are apply to the semiconductor MOSFET control in step down converter is ended at some point and released at some point depending upon the load and threshold values of output voltage of the converter.