OPERATIONAL OPERATIONAL AMPLIFIERAMPLIFIER
Submitted by:
OPERATIONAL OPERATIONAL AMPLIFIERAMPLIFIER
OP- AMP is a solid state device capable of sensing and amplifying dc and ac input signals.
OP- AMP is a high gain differential amplifier with nearly ideal external characteristics.
OP-AMP OP-AMP COMPONENTSCOMPONENTS
• TransistorsTransistors
• ResistorsResistors
• DiodesDiodes
• CapacitorsCapacitors
OP-AMP STAGESOP-AMP STAGES
NON INVERTING
INPUT
INVERTING INPUT
OUTPUT
DUAL-INPUT BALANCED
OUTPUT DIFFERENTIAL
AMPLIFIER
DUAL-INPUT UNBALANCED
OUTPUT DIFFERENTIAL
AMPLIFIER
EMITTER FOLLOWER
WITH CONSTANT CURRENT SOURCE
COMPLEMENTARY SYMMETRY PUSH-PULL AMPLIFIER
CIRCUIT SYMBOLCIRCUIT SYMBOL
The OP-AMP is represented by a triangular symbol.
It has two input and one output terminals.
EQUIVALENT EQUIVALENT CIRCUITCIRCUIT
Non InvertingInput
Inverting Input
Output
Vout = G(v1-v2)
1
2
CHARACTERSTICS OF CHARACTERSTICS OF IDEAL IDEAL OP-AMPOP-AMPCHARACTERISTICS IDEAL VALUES
Voltage gain ∞ Input impedance
∞
Output impedance
0
Bandwidth ∞ Input offset voltage
0
Input offset current
0
Slew rate ∞ CMRR ratio ∞
OP-AMP OP-AMP CONFIGURATIONSCONFIGURATIONS
INVERTING OP-AMPINVERTING OP-AMP
• An inverting amplifier uses negative feedback
to invert and amplify a voltage.
Output is 180° out of phase.
For the non-inverting amplifier the input is
connected to the non-inverting input.Output is in phase with the input.
NON-INVERTING OP-NON-INVERTING OP-AMPAMP
A particular form of this amplifier is when the
feedback loop is a short circuit, I.e. R2 = 0. Then
the voltage gain is 1, such an amplifier is called a
Voltage Follower.
(GROUND)
VOLTAGE FOLLOWERVOLTAGE FOLLOWER
Vout = Vin
•An inverting amplifier can accept two or more inputs
and produce a weighted sum
At X, I = IA + IB + IC = -(VA/RA+VB/RB+VC/RC)
SUMMING SUMMING AMPLIFIERAMPLIFIER
C
C
2B
B
2A
A
2out .V
R
R.V
R
R.V
R
RV
VA
VB
VC
SUBTRACTOR SUBTRACTOR AMPLIFIERAMPLIFIER
Amplifies the difference between the two voltages applied at the two ends of the amplifier.
Neither of the input lines is grounded. Noise appearing at both the input terminals
does not appear at the output.
Integrator produces an output voltage which is
proportional to the time integral of the input voltage
Integrating both sides gives
INTEGRATOR INTEGRATOR AMPLIFIERAMPLIFIER
.dtVRC
1dV inout
2
1
t
tin1out2out.dtV
RC
1tVtV
The function of an differentiator is to give an
output voltage which is proportional to the rate of input voltage.
DIFFERENTIATOR DIFFERENTIATOR AMPLIFIERAMPLIFIER
PRACTICAL PRACTICAL APPLICATIONSAPPLICATIONS• Perform math operationsPerform math operations
• ADC and DACADC and DAC
• Sign changerSign changer
• Voltage RegulationVoltage Regulation
• Pulse generatorsPulse generators
• Wave generator Wave generator