Eunreg 17 Vdc Vload 7 Vdc Iload 05 Adc f 110 kHz L 324

Eunreg = 17 Vdc Vload = 7 Vdc Iload = 0.5 Adc f = 110 kHz L = 324 uH C = 707 pF RQon = 0.3 Vdiode on = 0.4V Efficiency = 82%

a. - Calculate the duty cycle. Answer in %

b. - Calculate the ripple current through the inductor, iLpp. Answer in mA

c. - Calculate the maximum current through the inductor, iLmax. Answer in mA.

f. - Calculate the power dissipated by the load. Answer in W.

g. - Calculate the power supplied by Eunreg. Answer in W. h. - Calculate the current supplied by Eunreg. Answer in mA. i. - Calculate the power that the MOS must dissipate. Answer in mW.

j. - Calculate the power that the diode must dissipate. Answer in mW.

Solution

a- duty cycle = 7 + 0.4 / 17

= 63

b, ripple current = Vs/4f*L

= 7/ 440* 324*10^-3

   ⁼ 49 mA

C. I max = Vs/ R ( (1- e^ton/T )/( 1 - e-^ton/T) - E/R

= 108 mA

D. POWER DISSIPATION = V² /R = 49/.3 = 163.33W

E. POWER SUPPLIED = E* I = 17*108 *10^-3

     = 1.836 W

F . Power dissipate across diode = Vdiode * I

= 47.2 mW