Design and Simulation of Buck PMW DC-DC Converter

Now a day's dc-dc switching converters are widely used for sophisticated application. By using these converters with given dc input voltage a stabilised output voltage can be obtained by using Buck (lower), Boost (higher) or Buck –Boost (generic) topology which improves the efficiency of dc-dc converter as compared to linear regulators. Most used technique to control switching power supply is pulse width modulation (PWM). In this way a particular dc-dc converter is designed by keeping the typical application in mind. Properly designed dc-dc converters provide low ripple, better noise rejection, reliable and efficient converter. For some typical application like powering LED needs constant current supply for constant illumination, hence feedback based closed loop converters becomes better choice. In the present thesis for low power application a PWM based closed loop dc-dc buck converter has been designed, analysed and simulated. A MOSEFET has been used as switching device and components has been designed for low ripple and low noise. With variation in load and variation in input power supply output supply voltage has been obtained as constant value by using PID.