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Unformatted text preview: $élcetti’l/U ECE433Exam 1, February 18, 2011, 6:007:45 PM
Name: PUID: Note: For each question, you have to develop the mathematical equations and show
the comprehensive work to get the credit. Do not write any final equation without showing the procedure. Otherwise, you do not get the credit. 1) True/False (Brieﬂy explain your answer) (10 points):
a) In a DCDC converter under steadystate conditions, the net change of inductor . . . p 7 '1) .
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ml 4L3 ﬁe sex/Mtg ilk/Wag mama, 2 2—a) For an ideal buck converter, derive the value forfswCCHt) in terms of duty cycle,
switching frequency, and load, at the boundary of DCM and CCM. fswmit) refers to the value of switching frequency for which the converter operates in the boundary of DCM
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the voltage conversion ration of the converter Q1 switches ON and OFF with a
switching frequency of f5W and with a duty cycle of D (15 points). 4) For the given converter, Vg = 50V,L = 5mH,C = 20yF,R = 20,0 = 0.2,fsw =
100kHz. a) Assume that the MOSFET has a voltage drop of VTon during conduction.
Determine the voltage conversion ratio (5 points). b) Determine the efficiency of the converter under the condition of part b) (4
points). c) Determine the rating values (voltage and current) of the MOSFET and diode
(4 points). d) Assume VTon = 1V, plot the voltage and current of each individual
component, i.e. switch, diode, inductor, and capacitor in steadystate.
Determine ML and AVC and include them on the graphs (for each graph show
the numerical values for magnitude and time information) (12 points). 04t (DIS (m at) , 0, roar) 030505 {(156%) r). :m) up + V1": +(ijcycgi L59“??? ._,. » ([7 7;] 
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This note was uploaded on 03/25/2011 for the course ECE 433 taught by Professor Staff during the Spring '08 term at Purdue UniversityWest Lafayette.
 Spring '08
 Staff

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