University of Toronto

Faculty of Applied Science and Engineering

Final Examination, April 2019

Duration 2% hours

MIE346H1S

-

Analog

& Digital Electronics

1*

11

011) Dozy well

FAMILY NAME

I

LAST

NAME:

Please do not detach any pages except the equation sheet!

Instructor Matthew Mackay

Rules and Guidelines:

The examination is 10

and is comprised of three (3) questions, worth a total of 100

points. You should attempt all questions.

The exam book contains 11 pages, including this one. You must answer all questions within the

cannot be submitted for marking. Use the back of the page for extra graded space when needed.

This exam is closed-book. No external material is allowed, such as lecture or tutorial notes,

midterms, final exams, books, or formula pages. Calculators and rulers are allowed.

Clearly highlight all final answers, and show all intermediate workings. We cannot give partial

marks if you do not.

Question 1

/25

Question 3

/30

Question 2

/

45

Total

/

100

Student Number:

Last Name:

Question 1

-

Consider

the power supply

,

circuit below, which you are designing for a special application involving

high-

voltage DC output.

For both Part A and B, assume a CV model for the diodes, where

VD,,

=

5.5

V

(this larger-than-normal

forward drop is common for certain high-voltage diodes).

a) List what t'ou think are the two most

relevant

real-world

diode parameters

that one should consider in selecting rectifier

diodes for this design other than

1,'D0).

Assume that the power supply design goals and constraints are as follows:

Secondan

of the transformer is rated at:

VSEC

=

2500

V (RMS.

Center-tapped)

=

50KHz

not

Hz'

II

I

,

, >

1550

V

to operate

correctly.

Produces re

ulated 1500

V

output.

Provides ripple rejection.

Average Load Current:

'LOAD

100

mA

Output Voltage:

VOUT

=

1500

V

Maximum Allowable Ripple: 210

mV

Workings

(if

needed)

H

_

/8

Page 2

11

Student Number:

Last Name:

(b) To

rninlmi7e

the size and cost of the design you are to find the smallest possible capacitor value, C, and corresponding

regulator ripple rejection, RR, which will still meet the requirements from Part A. The overall power supply must function

VOUT

(i.e., the regulator must always operate correctly). Calculate the peak inverse

voltage seen by the rectifier diodes in your design.

/171

Page 3 / 11