MIKROE-957 mikroElektronika, MIKROE-957 Datasheet - Page 24

• Manufacturer Part Number: MIKROE-957
• Description: Other Development Tools ASLK PRO ANALOG DEVELOPMENT SYSTEM
• Manufacturer: mikroElektronika

Specifications of MIKROE-957

• Rohs: yes
• Product: Analog System Lab Kit PRO
• Tool Is For Evaluation Of: TL082, MPY634
• Operating Supply Voltage: 2.5 V to 5.5 V
• Description/function: Analog Lab Kit for Undergraduate Engineering
• Maximum Operating Temperature: + 125 C
• Minimum Operating Temperature: - 40 C

2.1.1 Inverting Regenerative Comparator
In the earlier experiment we had discussed the use of only negative feedback. Let
us now introduce the case of regenerative positive feedback as shown in Figure 2.1.
The reader will benefit by listening to the recorded lecture at [20].
Figure 2.1: Inverting Schmitt-Trigger and its Hysteresis Characteristic
page 24
2.1 Brief theory and motivation
The goal of this experiment is to understand the basics of hysteresis and
the need of hysteresis in the switching circuits.
+
Goal of the experiment
V
I
R
1
+
-
V
V
2
T
t
b
b
x
V
V
+V
A
A
A
0
-V
ss
+
0
i
R
V
V
$
b
b
V
V
V
V
=
$
V
V
=
=
=
SS
0
0
SS
2
0
A
A
A
A
0
b
0
=-
V
0
0
ss
ss
i
i
$
$
$
x
=
=
=
=
0
0
0
0
ss
b
b
b
-
2
$
=-
=-
RC
R
$
$
$
$
V
b
b
b
b
-
-
1
$
ss
R
R
A
=
1
&
RC
A
+
R
1
1
$
0
A
A
0
1
V
A
A
+
+
=
=
1
1
R
R
ln
$
R
1
O
1
$
1
0
0
_
0
0
1
1
$
1
2
$
$
V
d
R
R
1
1
$
$
1
1
ln
_
_
1
i
1
1
1
-
V
V
2
2
-
d
+
i
i
-
-
-
1
1
-
-
A
1
1
b
b
0
b
1
1
A
A
+
-
V
b
b
$
0
0
0
n
b
V
V
i
b
$
$
b
0
0
b
b
i
i
n
(2.1)
(2.2)
(2.3)
+
-
V
b
b
V
2
T
x
t
x
!
R
R
R
x
RC
V
b
V
f
A
A
A
0
0
ss
+
i
1
2
However, when
unstable as amplifier as output satu-
rates. When
operation of this circuit is regenerative
comparator. This is the mixed-mode
circuit. Output is stable only in two
stages
is large negative value output saturates
at
remain at
at this point it changes to stable state
can change state only at
of comparator is a must while driving a MOSFET as a switch in ON-OFF controllers
SMPS (Switched Mode Power Supply), pulse width modulators and class-D audio
power amplifiers. The symbol for this inverting type Schmitt trigger is shown in
$
Figure 2.2. The non-inverting Schmitt trigger is as shown in Figure 2.3.
1
2.1.2 Astable Multivibrator
An astable multivibrator is shown in Figure 2.4. The square and the triangular
waveforms shown in the figure are both generated using the astable multivibrator.
We refer to
given by
V
V
=
=
$
=
=
=
=
0
0
0
=
b
=-
V
V
ss
ss
$
$
$
x
ss
-
b
b
b
. Now when the input is decreased it
2
RC
$
RC
1
T
4
R
+
-
R
V
V
2
T
t
!
V
b
b
V
x
x
b
R
R
R
x
RC
V
f
A
A
A
1
$
1
ms
0
ss
+
0
i
ss
1
2
A
1
=
V
V
$
=
=
A
+
=
1
&
$
=
RC
V
+
=
=
R
=
R
=
0
0
0
b
$
=-
V
$
V
0
ss
ss
$
0
$
1
$
x
I
1
Figure 2.3: Non-inverting Schmitt Trigger and its Hysteresis Curve
ln
ln
$
ss
1,5
b
b
+
b
-
V
-
$
R
1
1
V
1
2
T
$
x
2
t
x
!
RC
R
x
T
V
b
b
RC
b
R
R
R
1
RC
4
V
_
R
R
f
A
A
A
$
0
1
V
V
2
as input in increased output
ss
+
d
2
0
i
d
1
2
$
$
1
1
V
V
=
ln
1
=
ms
$
=
=
=
A
=
0
0
0
+
-
ss
2
=
1
=
V
i
b
b
V
T
x
t
1
x
!
b
R
R
R
x
RC
A
V
V
+
=
-
1
&
b
RC
+
=-
R
V
V
R
f
ss
ss
kHz
-
A
A
A
$
0
$
$
$
ss
x
$
+
0
0
i
d
+
R
1
2
+
-
0
1
ss
$
-
1
1
V
=
V
2
T
t
b
b
b
V
V
$
2
=
RC
ln
b
V
b
b
x
x
-
=
$
RC
ln
=
=
1
T
4
=
V
$
=
0
0
0
1
1,5
R
1
A
1
1
R
=-
R
1
1
b
R
A
A
A
$
1
and
V
V
1
0
ss
+
_
b
ss
ss
V
0
i
$
$
$
+
-
2
x
V
V
$
=
b
1
b
V
T
x
$
t
x
$
!
b
R
R
R
x
RC
ms
$
=
V
V
1
0
ss
d
b
1
b
=
0
0
0
V
2
ss
d
+
-
f
2
=
as the regenerative feedback. The time period of the multivibrator is
A
-
b
b
b
2
RC
=
T
b
A
A
A
V
$
ln
RC
1
4
=-
V
0
A
+
=
1
&
ss
RC
+
+
ss
ss
0
R
R
$
until input reaches
1
R
R
i
i
1
1
2
$
$
$
x
-
$
V
1
$
=
V
0
V
$
=
$
n
=
0
=
=
n
=
kHz
ss
0
-
0
0
b
b
b
b
2
RC
0
1
1
$
1
1
-
ms
$
RC
=-
i
b
ln
+
-
V
2
t
d
ss
ln
V
!
b
b
+
R
$
b
A
ss
ss
b
V
T
x
x
-
b
R
R
R
x
RC
1,5
=
V
V
$
$
$
=
1
&
RC
$
R
A
1
1
R
+
1
x
b
R
f
R
+
V
1
V
_
A
A
1
A
A
+
-
V
2
T
t
!
0
b
ss
ss
b
x
+
1
1
x
b
R
$
R
R
x
RC
$
0
V
V
b
b
0
b
2
$
RC
$
1
T
1
i
1
$
RC
n
2
1
4
f
ss
b
2
$
1
d
2
=
A
V
R
A
A
0
V
A
1
V
$
=
d
R
ln
1
0
=
ss
=
+
ln
=
=
A
+
=
1
&
RC
=
0
0
0
0
0
V
ln
b
1
R
i
$
b
2
1,5
=-
R
b
1
$
+
-
V
1
1
R
=
$
i
V
$
V
1
V
V
1
$
=
1
$
1
-
=
_
ss
ss
$
=
1
=
ms
=
0
=
$
$
0
$
0
0
$
ss
x
kHz
0
1
-
=-
1
b
$
V
=
ln
=
1
&
ss
V
RC
n
ln
A
+
0
V
2
ss
ss
n
+
d
2
$
-
R
b
b
$
b
b
$
$
2
d
RC
d
R
+
T
$
RC
x
-
1
4
$
R
1
1
i
$
ln
1
0
R
ss
$
b
b
b
R
_
1
1
-
1
A
i
b
b
-
b
. When the input
V
2
1
1
RC
1
T
0
1
$
RC
ln
1
1
4
1
$
ln
kHz
d
b
R
R
V
2
d
1
-
$
1
1,5
ms
R
V
R
+V
ln
$
1
1
1
ss
+
-
0
V
b
n
b
d
V
b
2
T
+
x
t
=
x
!
b
R
R
R
x
RC
1
=
1
&
V
RC
+
-
b
-
-V
i
1
A
R
+
1
V
$
R
+
1
b
ms
-
f
1
V
$
1
A
1
A
ss
A
A
R
2
$
A
0
d
$
1
1
2
+
=
-
0
=
1
&
0
d
RC
$
ss
A
R
+
i
R
+
1
2
0
b
ln
n
$
1
=
d
+
0
1
V
V
n
ln
1
=
-
b
the region of
=
ln
1
$
$
=
SS
=
=
i
-
0
=
0
0
0
1
$
b
2
SS
i
0
b
1,5
1
R
1
1
b
b
+
-
b
R
kHz
1
A
1
1
$
0
1
1
=-
V
ln
1
V
V
ss
ln
ss
$
$
$
$
$
x
1,5
b
1
R
1
1
d
$
+
R
+
-
$
, it becomes
1
-
2
t
_
2
0
d
d
b
ss
2
V
n
b
0
b
V
T
x
b
-
b
b
1
b
n
. Thus hysteresis of
n
2
V
RC
T
b
1
b
$
RC
V
1
4
+
-
A
1
i
1
ln
1
$
V
R
d
R
V
2
d
1
b
b
2
i
-
1
V
$
ln
A
A
A
0
kHz
0
n
-
b
ss
n
+
0
1
b
1
1
$
0
1
b
ms
i
-
+
-
i
ss
i
A
d
+
n
kHz
=
$
b
b
-
=
1
&
-
RC
V
V
=
$
A
+
b
+
$
=
R
1
=
R
1
0
0
0
0
A
1
1
d
n
+
=
$
n
-
$
b
0
b
b
1
=-
1
0
1
1
V
n
A
b
b
1
1
ln
ln
ss
ss
b
0
$
b
1,5
b
R
+
-
$
R
$
$
$
1
1
1
x
_
b
$
0
b
1
n
+
-
$
ss
0
V
V
+
-
2
2
n
-
d
b
2
b
b
2
b
V
b
b
V
n
T
x
t
x
!
d
b
R
R
R
x
RC
$
V
V
$
RC
ln
f
b
b
0
A
A
A
n
1
R
b
0
i
ss
n
+
1
0
-
V
i
i
1
2
kHz
V
b
$
b
1
=
-
V
V
=
=
$
=
=
=
=
0
0
0
n
d
+
O
=-
b
-
$
V
V
b
1
ss
ss
$
$
$
1
1
A
n
x
1
1
ss
A
b
ss
=
1
&
RC
-
b
b
b
2
RC
A
+
T
$
RC
R
1
4
b
R
0
b
R
+
-
V
V
$
0
$
1
$
1
ms
0
ss
0
n
1
A
n
=
=
1
&
b
RC
ln
A
+
+
R
i
R
b
b
$
$
$
R
0
$
1
1
1
0
1
ln
1
ln
_
$
n
1,5
R
R
$
1
1
1
1
$
_
V
2
Analog System Lab Kit PRO
1
$
d
Figure 2.2: Symbol for an Inverting
V
2
d
2
d
ln
ln
1
i
1
i
1
-
-
kHz
-
-
+
-
d
+
V
V
2
T
-
x
t
x
!
x
V
b
b
b
b
R
R
R
RC
V
f
1
d
1
A
A
A
A
1
1
0
-
ss
+
b
0
i
1
2
$
1
V
V
=
=
1
$
=
b
1
=
=
0
=
0
0
0
b
=
A
1
1
+
-
b
V
=-
V
V
ss
ss
$
b
$
$
$
x
0
n
ss
n
-
b
b
b
b
2
RC
$
RC
0
1
T
4
i
b
R
b
b
R
+
-
V
V
$
$
ms
1
1
ss
n
A
=
Schmitt Trigger
A
+
=
1
&
RC
0
+
R
R
n
b
$
$
0
i
0
1
1
b
b
is seen around 0. This kind
ln
ln
$
1,5
$
R
1
1
1
R
_
$
1
2
d
2
V
d
n
ln
1
i
1
-
kHz
-
d
+
-
b
1
1
A
1
1
b
0
b
+
-
b
V
$
0
n
n
b
i
b
b
n
(2.4)