The document outlines a course on Pulse & Digital Circuits offered by the Electronics and Communication Engineering department at East Africa University. It covers topics such as linear and non-linear wave shaping, switching characteristics of devices, multivibrators, and time base generators, along with their applications in circuits. The course aims to enhance students' understanding of waveforms, circuits' responses to various inputs, and practical circuit designs.

1. East Africa University
DEPARTMENT OF ELECTRONICS AND COMMUNICATION
ENGINEERING
SUBJECT NAME: PULSE & DIGITAL CIRCUITS
LECTURER NAME: Abdulkadir. M . Daar

2. PULSE & DIGITAL CIRCUITS
COURSE OBJECTIVES:
The student will be made
To understand the concept of wave shaping circuits,
Switching Characteristics of diode and transistor.
To study the design and analysis of various Multivibrators.
To understand the functioning of different types of time-
base Generators.

3. UNIT I
LINEAR WAVESHAPING- High pass, low pass RC circuits, their response for
sinusoidal, step, pulse, square and ramp inputs. RC network as differentiator and
integrator, attenuators, its applications in CRO probe, RL and RLC circuits and their
response for step input, Ringing circuit.
UNIT II
NON-LINEAR WAVE SHAPING- Diode clippers, Transistor clippers, clipping at two
independent levels, Comparators, applications of voltage comparators, clamping
operation, clamping circuits taking source and diode resistances into account clamping
circuit theorem , practical clamping circuits, effect of diode characteristics on clamping
voltage, Synchronized clamping
PULSE & DIGITAL CIRCUITS

4. UNIT III
SWITCHING CHARACTERISTICS OF DEVICES- Diode as a switch, piecewise linear
diode characteristics, Transistor as a switch, Break down voltage consideration of
transistor, saturation parameters of Transistor and their variation with temperature,
Design of transistor switch, transistor-switching times. Silicon controlled switch circuits.
UNIT IV
MULTIVIBRATORS- Analysis and Design of Bistable, Monostable, Astable
Multivibrators and Schmitt trigger using transistors.
UNIT V
TIME BASE GENERATORS- General features of a time base signal, methods of
generating time base waveform, Miller and Bootstrap time base generators – basic
principles, Transistor miller time base generator, Transistor Bootstrap time base
generator, Current time base generators. Methods of linearity improvement.
PULSE & DIGITAL CIRCUITS

5. MODULE-I: Linear wave shaping
CONTENTS:
 High pass RC circuits with Step, Pulse, Square wave and Ramp inputs
 Low pass RC circuits with Step, Pulse, Square wave and Ramp inputs
 High pass RC circuit as Differentiator
 Low pass RC circuit as Integrator
OUTCOMES:
To derive the response of high-pass and low-pass RC circuits to different types
of inputs like Sinusoidal, pulse, step, square, ramp signals.
To describe the application of high pass and low pass circuit as Differentiator
and integrator respectively.

6. Analog and Digital Systems
• Digital systems can process, store, and transmit data more
efficiently but can only assign discrete values to each
point
CDdriv
e
10110011101
Digital
data
Analog
reproduction
ofmusic
audio signal
Speaker
Soun
d
waves
Digital-to-
analog
converter
Linearamplifier

7. Cont..
• Digital electronics uses circuits that have two states, which
are represented by two different voltage levels called HIGH
and LOW. The voltages represent numbers in the binary
system
• In binary, a single number is called a bit (for binary digit). A
bit can have the value of either a 0 or a 1, depending on if the
voltage is HIGH or LOW.

8. DigitalSignals
• Digital waveforms change between the LOW and HIGH
levels. A positive going pulse is one that goes from anormally
LOW logic level to a HIGH level and then back again.
Digital waveforms are made up of a series of pulses
Falling or
leadingedge
(b)Negative–going pulse
HIGH
Rising or
trailingedge
LO
W
(a) Positive–
goingpulse
HIGH
Rising or
leadingedge
Falling or
trailingedge
LOW
t0
t1
t0
t1

10. Periodic Pulse Waveforms
• Periodic pulse waveforms are composed of pulses that repeats
in a fixed interval called the period.
• The frequency is the rate it repeats and is measured in hertz.
The clock is a basic timing signal that is an example of a
periodic wave.
What is the period of a repetitive wave if f = 3.2 GHz?

11. Pulse Definitions
• In addition to frequency and period, repetitive pulse
waveforms are described by the amplitude (A), pulse width
(tW) and duty cycle. Duty cycle is the ratio of tW to T.
Volt
s
Pulse
width
(tW)
Tim
e
Period,
T
Amplitude

12. LINEAR WAVESHAPING
Linear elements such as resistors, capacitors and inductors are
employed to shape a signal in this linear wave shaping. A Sine
wave input has a sine wave output and hence the non-sinusoidal
inputs are more prominently used to understand the linear wave
shaping.

13. DEFINITION: It is the process of changing the shape of input signal
with linear / non-linear circuits.
Wave Shaping
Types
 Linear Wave Shaping
 Non-linear Wave Shaping

14. DEFINITION: The process where by the form of a non-
sinusoidal signal is changed by transmission through a linear
network is called linear wave shaping.
Linear Wave Shaping
Types
 High Pass RC Circuit.
 Low Pass RC Circuit.

15. Non-sinusoidal wave forms
1. Step Waveform: A step voltage is one which
maintains the value zero for all times t<0 and
maintains the value V for all times t>0.

16. 2. Pulse Waveform: The pulse amplitude is V
and the pulse duration is tp.

17. 3. Square Wave: A wave form which maintains
itself at one constant level V1 for a time T1
and at other constant Level V11 for a time T2
and which is repetitive with a period T=T1+T2 is
called a square-wave.

18. 4.Ramp: A waveform which is zero for t < 0 and
which increases linearly with time for t > 0.

19. 5. Exponential
0
t
• The exponential waveform input is given by
where T is the time constant of the exponential
input
Vi
V