Inductor Ripple Current
{"Image DocumentName": "Inductor Ripple Current", "Image ImageDescription": "On. Time. Voltage applied. dI = (1/L) V dt. Inductor Ripple Current (also determines peak switch current and Vout ripple) The peak inductor current (and peak switch current) is a function of the average output current and the inductor ripple current. The peak inductor current is: ILaverage + 1/2 ILpp (the inductor ripple current) The average inductor current is: For Buck: ILaverage = Iout. For Boost: ILaverage = Iout/(1-DC) where DC = duty cycle. DC = (Vout-Vin+Vdiode+ILavg DCR)/(Vout - Vswitch + Vdiode) Higher DCR means higher duty cycle and higher average inductor current. The inductor ripple current is determined by the basic inductor equation: V = L dI/dt. di = V/L dt. Peak to peak inductor current (inductor ripple current) = Voltage applied across the inductor/L   time during which voltage is applied to the inductor. When the switch is closed we have: For Buck: ILpp = (Vin - Vswitchingloss - ILavg DCR - Vout)/L   Ton. For Boost: ILpp = (Vin - Vswitchingloss - ILavg DCR)/L   Ton. Since the on time is: Ton = duty cycle/switching frequency. We see that the on time is inversely proportional to the switching frequency. So the lower the switching frequency, the higher the inductor ripple current and thus peak inductor current.", "Image XResolution": "37", "Image YResolution": "37", "Image ResolutionUnit": "Pixels/Centimeter", "Image Software": "SlidePlayer", "Image YCbCrPositioning": "Centered"}