Cuk converter is the series combination of boost and the buck converter. The Cuk converter is the DC to DC converter whose output voltage is greater than or less the than the input voltage. The polarity of the output voltage is opposite of input voltage. Cuk converter has low ripple because of less switching component and use of an inductor in series at the input and at the output. Cuk converter can also be used with the isolated transformer form. By controlling the switch duty cycle the output voltage can be controlled.