An LC filter (inductor and capacitor) is used to smooth the pulsed signal into a stable DC output. Primary Converter Topologies
The primary mechanism of a PWM converter is the , which is the ratio of the switch "on-time" ( Toncap T sub o n end-sub ) to the total switching period ( Pulse Width Modulated DC-DC Converters
D=TonT×100%cap D equals the fraction with numerator cap T sub o n end-sub and denominator cap T end-fraction cross 100 % An LC filter (inductor and capacitor) is used
While the pulse width varies, the frequency typically remains constant, often in the kilohertz (kHz) to megahertz (MHz) range to minimize the size of passive components. the frequency typically remains constant
PWM DC-DC converters are categorized based on their ability to step voltage up or down: