Question

To design a high efficiency d.c., to d.c power converter with the given specifications min 10V max 15V nominal (regulated) 8V Input voltage: Output voltage: Nominal load current: 4A Inductor current ripple: 0.1A max Switching frequency: 30 kHz Output voltage ripple: 20 mV Define a suitable power circuit topology to meet the above specification? Sketch a circuit diagram of the chosen power circuit topology (a) Define the minimum and maximum duty cycles assuming that the control circuit keeps the output voltage constant at the nominal value (b) Given the above specification, what would be the maximum input current (assuming the load current is constant at the nominal value) (c) (d) Design a suitable converter power circuit using a MOSFET switch showing all calculation of inductor and capacitor values and drawing a circuit diagram of the final design including component values. Indicate the peak inverse voltage and forward current rating of any diode required, and the maximum drain-source voltage of the MOSFET.

Answer 1

# dctodc convento, oudpu o taçe output voltage sripple 2omu a) fon the given sreguinement, autput voftage s less than input nvoltage used to get sneguiyedd outpel votagr con be uued Buck Conventor Switch id c R Clood) b minimum and maximum Buck Conveytos fos minimum duty syele (min og minimum in 3 minimum du

for masimum du ty cyele m8 maximum duty ycle wing power alan imum inpu cusrent duty cycle should dCalculatimo the yatuu of inductos Onol aci when duty cycle min0 S33 0.533(1-0533) x1 30x103し 0.1 L = 124 mH

opi when mae o-8 ㄥ L= 0.533 x10-3 H ! So inductance Seguiyed for capacito 30x10-3-0-1 c= ao.gx1 59 F