EC8453-IC-linear integrated circuit analysis

Circuit analysis for EC 8453 Ic

1. EC8453 LINEAR INTEGRATED
CIRCUITS

2. 2
Linear integratedcircuits
Alinearintegratedcircuit(linearIC)isa
solid-stateanalogdevicecharacterizedbya
theoreticallyinfinitenumberofpossible
operatingstates.Itoperatesovera
continuousrangeofinputlevels

3. 3EEE-
BIHER
Linear ICs are employed in
audioamplifiers,
A/D (analog-to-digital) converters,
averaging amplifiers,
differentiators,
DC (direct-current) amplifiers,
integrators,
multivibrators,
oscillators,
audio filters,and
sweepgenerators.
APPLICATIONS

4. 4EEE-
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OPERATION
AMPLIFIER
Anoperationalamplifierisadirectcoupledhigh
gainamplifierconsistingofoneormoredifferential
amplifiers,followedbyaleveltranslatorandan
outputstage.

5. 741 Op-AmpSchematic
5

6. 6
Idealcharacteristicsof
OPAM
P
1.OInput pen loop gain infinite
2.impedanceinfinite
3.Output impedancelow
4.Bandwidthinfinite
5.Zero offset, ie, Vo=0 when
V1=V2=0

7. Op-amp
symbol
invertinginput
7EEE-
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0utput
+5v
Non-invertinginput
2
3
6
7
4
-5v
LinearIntegratedCircuits−AnanalogICissaidtobe
Linear,ifthereexistsalinearrelationbetweenits
voltageandcurrent.IC741,an8-pinDualIn-line
Package(DIP)op-amp,isanexampleofLinearIC.

8. Op
Amp
Positive powersupply
(Positiverail)
Non-inverting
Inputterminal
Outputterminal
Invertinginput
terminal
Negative powersupply
(Negativerail)
8EEE-
BIHER

9. Inverting amplifier
example
R
2
•Applying the rules: terminal at “virtual
ground”
–so current through R
1 is I
f =V
in/R
1
•Current does not flow into op-amp (one of
our rules)
–so the current through R
1 must go throughR
2
–voltage drop across R
2 is then I
fR
2 =V
in(R
2/R
1)
•So V
out = 0 V
in(R
2/R
1) =V
in(R
2/R
1)
•Thus we amplify V
in by factorR
2/R
1
–negative sign earns title “inverting”amplifier
•Current is drawn into op-amp outputterminal

+
V
in
9
V
out
R
1

10. Non-inverting
Amplifier
R
2
•Now neg. terminal held atV
in
–so current through R
1 is I
f = V
in/R
1 (to left, intoground)
•This current cannot come from op-amp input
–so comes through R
2 (delivered from op-ampoutput)
–voltage drop across R
2 is I
fR
2 =V
in(R
2/R
1)
–so that output is higher than neg. input terminal by
V
in(R
2/R
1)
–V
out = V
in + V
in(R
2/R
1) = V
in(1 +R
2/R
1)
–thus gain is (1 + R
2/R
1), and ispositive
•Current is sourced from op-amp output in thisexample

+V
in
V
out
R
1
10

11. Voltage
follower
11

12. Differentiat
or
12

13. Integrat
or
13

14. Differential
Amplifier
If R
1 = R
2 and R
f =
R
g:
14

15. Summing
Amplifier
•Much like the inverting amplifier, but
with two inputvoltages
–inverting input still held at virtualground
–I
1 and I
2 are added together to run through
R
f
–so we get the (inverted) sum: V
out =
R
f(V
1/R
1
+V
2/R
2)
•if R
2 = R
1, we get a sum proportional to (V
1 +

+
V
out
R
1
V
1
R
f
V
2
R
2
15

16. Comparat
or
Determines if one signal is bigger than
another
V
1 is
V
ref
V
2 is
V
in
16

17. 17
Applications of
comparator
1.Zero crossing
detector
2.Windowdetector
3.Time marker
generator
4.Phasedetector

18. Schmitt
trigger
18

19. square wave
generator
19

20. Instrumentation
Amplifier
v
OUT = (R2/R1)(1 + [2R
B/R
A])(v1 –v2)
By adjusting the resistor R
A, we can adjust the gain
of this instrumentationamplifier
20

21. 21
Analog-to-digital converter
(ADC)
•An analog-to-digital converter
(ADC) converts real-world signals
(usually voltages) into digital
numbers so that a computercan:
–acquire signalsautomatically,
–store and retrieve information about
the signals,
–process and analyze theinformation,
–display measurementresults.

22. •The comparator—the essential building block of allADCs.
(a)Comparator symbol. (b) Comparator I/O transfer
function.
22

23. 23
Types ofADCs
•There are 5 major types ofADCs:
–Flash (parallel)converters,
–Dual-slope, integratingconverters,
–Successive-approximationconverters,
–Tracking (servo)types,
–Dynamic range, floating pointconverters.
•The fastest ADCs are the flash converters.
They can convert 8 bits with a sampling
period of less than 1 ns. Such fast speed is
useful for measuring transient phenomena.
E.g. Transient events in particle physics and
lasers.

24. 24
Flash (parallel)converter
•Since Flash ADCs (FADCs) is simple-structured,
they arefast.
•A string of resistors between two voltage references
supplies a set of uniformly spaced voltages that span
the input range, one for each comparator. The input
voltage is compared with all of these voltages
simultaneously.
•Comparator outputs = 1 for all voltages below the
input voltage
•Comparator outputs = 0 for all the voltages above
the inputvoltage.
•The resulting collection of digital outputs is calleda
“thermometercode”.

25. 17•A flash converter has 2
n-1 comparators operating in
parallel.

26. Flash converter (More Complicated
example)
•3-bit flash ADC
with binary
output.
26

27. 27
Integratingconverter
•Integrating converters are used for low-
speed, high-resolution applications
such as voltmeters. They are
conceptually simple, consisting of an
integrating amplifier, a comparator, a
digital counter, and a very stable
capacitor for accumulatingcharge.

28. 28
Integratingconverter
•The most common integrating ADC in
use is the dual-slope ADC. Its action is
illustrated in the nextslide.

29. Integratingconverter
•A dual-slope integrating converter uses a comparator
to determine when the capacitor has fully
discharged.
29

30. Integratingconverter
•At time 0, the input is switched to analog input and the switch
across the capacitor opens. After the capacitor is integrated, the
input is switched to the voltage reference to discharge the
capacitor, and the counter begins counting a known clock. The
comparator turns off the counter at timeT2.
30

31. 31
Integratingconverter
•Dual-slope integrating ADCs (DSI-
ADCs) have the advantages of high
inherent accuracy (up to 22 bits
output), excellent high-frequency noise
rejection. They are widely used in
inexpensive DC digital instruments.

32. 32
Digital-to-analog converter
(DAC)
•A digital-to-analog converter (DAC) is an
integrated circuit (IC) device which converts
an N bit digital word to an equivalent analog
voltage or current. It allows digital information
which has been processed and/or stored by a
digital computer to be realized in analogform.
•After digitalization, a staircase waveform can
be smoothed by a low-pass filter. In this way,
an analog output signal isreconstructed.

33. 33
Digital-to-analog converter
(DAC)
•At sampling instants, the difference between
DAC output and the analog input signal is
called a quantizationerror.
•The quantization error of an ADC is
equivalent to½ least significant bit
(LSB).

34. DigitaltoAnalog
Conversion
A D/A Converter produces an analog voltage
proportional to the digitalinput.
Example:
D/A designed to output 0 to 10volts.
•Input to D/A is an 8 bit digitalvalue.
•Digital value 0 produces a 0 voltoutput.
•Digital value 1 produces a 1 x 10/256 voltouput.
•Digital value 2 produces a 2 x 10/256 voltoutput.
•Digital value 255 produces a 255 x 10/256 volt
output.

35. Typical 4-bit D/A
Converter

36. Parameters Affecting
D/A Converter
Performance
OutputRange
•The voltage difference between the max
and min output voltages of theD/A.
Accuracy
•Expressed as a percentage of the
maximum outputvoltage
•Or as an error of the least significant
bit (e.g.,+1/2LSB).
•Expected amount of accuracy in actual
output based on digitalinput.

38. The 555 timer is an 8-Pin D.I.L. Integrated Circuit or „chip‟

39. 555 Timer

40. IC 555
5kΩ
5kΩ
5kΩ
Discharge (7)
Reset (4)Ground (1)
Vcc(8)

41. •To switch on or off an output after a certain time delay i.e.
Games timer, Exercise timer.
•To continually switch on and off an output i.e.
warning lights, Bicycle indicators.
•As a pulse generator i.e.
To provide a series of clock pulses for a counter.
555 timer Applications

42. Schematic Diagram of 555 Timer