Download Chapter 6 The Operational Amplifier

Chapter 6: The Operational Amplifier
Chapter 6
The Operational Amplifier
©2001, John Wiley & Sons, Inc.
Introduction To Electric Circuits, 5th Ed
Chapter 6: The Operational Amplifier
Figure 6.1-1
Interfacing a pressure transducer with an
analog-to-digital converter (ADC).
©2001, John Wiley & Sons, Inc.
Introduction To Electric Circuits, 5th Ed
Figure 6.2-1
Chapter 6: The Operational Amplifier
Noble Prize winners John Bardeen, William Shockley, and Walter
H.Brattain (left to right), shown at Bell Telephone Laboratories in
1948 with the apparatus used in the first investigations that led to
the investigations that led to the invention of the transistor. The trio
received the 1956 Noble Prize in physics for their invention of the
transistor, which was announced by Bell Laboratories in 1948.
Courtesy of Bell Telephone Laboratories
©2001, John Wiley & Sons, Inc.
Introduction To Electric Circuits, 5th Ed
Figure 6.2-2
Chapter 6: The Operational Amplifier
The first transistor assembled by their inventors at Bell Laboratories (in 1947)
were primitive by today’s standards. Yet they revolutionized the electronics
industry and changed our way of life. The first transistor, a “point-contact” type,
amplified electrical signals by passing them through a solid semiconductor
material, basically the same operation as performed by present “junction”
transistors. The three terminal wires can be seen on the top of the transistor.
The actual record of the first transistor operation was December 23, 1947.
Courtesy of Bell Telephone Laboratories.
©2001, John Wiley & Sons, Inc.
Introduction To Electric Circuits, 5th Ed
Figure 6.2-3
Chapter 6: The Operational Amplifier
The first commercial transistor radio. The molded plastic
case of the Regency TR-1 radio was designed to fit into
1
the pocket of a man’s dress shirt. It was 5 by 3 by 1 4
inches and sold for $49.95. This radio was introduced on
October 18, 1954. Courtesy of Texas Instruments.
©2001, John Wiley & Sons, Inc.
Introduction To Electric Circuits, 5th Ed
Figure 6.2-4
Chapter 6: The Operational Amplifier
Inside view of the radio in Figure 6.2-3. The specially
designed miniature components barely fit inside the 5 by 3
1
by 1 4 inch case. The four transistors, discrete resistors,
capacitors, and other miniaturized components were
3
mounted, along with the 2 4 inch speaker, in the front half of
the plastic case. Courtesy of Texas Instruments.
©2001, John Wiley & Sons, Inc.
Introduction To Electric Circuits, 5th Ed
Chapter 6: The Operational Amplifier
Figure 6.3-1
(a) A μA741 integrated circuit has eight connecting pins.
(b) The correspondence between the circled pin
numbers of the integrated circuit and the nodes of the
operational amplifier.
©2001, John Wiley & Sons, Inc.
Introduction To Electric Circuits, 5th Ed
Chapter 6: The Operational Amplifier
Figure 6.3-2
An op amp, including power supplies ν
and ν.
©2001, John Wiley & Sons, Inc.
Introduction To Electric Circuits, 5th Ed
Chapter 6: The Operational Amplifier
Figure 6.4-1
The ideal operational amplifier.
©2001, John Wiley & Sons, Inc.
Introduction To Electric Circuits, 5th Ed
Chapter 6: The Operational Amplifier
Figure 6.4-2
(a) The operational amplifier
circuit for Example 6.4-1 and
(b) an equivalent circuit
showing the consequences of
modeling the operational
amplifier as an ideal
operational amplifier. The
voltages ν1, ν2, and νo are
node voltages and hence are
the voltages at the node with
respect to ground.
©2001, John Wiley & Sons, Inc.
Introduction To Electric Circuits, 5th Ed
Chapter 6: The Operational Amplifier
Figure E 6.4-1
©2001, John Wiley & Sons, Inc.
Introduction To Electric Circuits, 5th Ed
Chapter 6: The Operational Amplifier
Figure E 6.4-2
©2001, John Wiley & Sons, Inc.
Introduction To Electric Circuits, 5th Ed
Chapter 6: The Operational Amplifier
Figure 6.5-1
Circuit of Example 6.5-1.
©2001, John Wiley & Sons, Inc.
Introduction To Electric Circuits, 5th Ed
Chapter 6: The Operational Amplifier
Figure 6.5-2
(a) A bridge
amplifier, including
the bridge circuit.
(b) The bridge
circuit and,
(c) its Thévenin
equivalent circuit.
(d) The bridge
amplifier, including
the Thévenin
equivalent of
the bridge.
©2001, John Wiley & Sons, Inc.
Introduction To Electric Circuits, 5th Ed
Chapter 6: The Operational Amplifier
Figure E 6.5-1
©2001, John Wiley & Sons, Inc.
Introduction To Electric Circuits, 5th Ed
Figure 6.6-1
Chapter 6: The Operational Amplifier
A brief catalog of operational amplifier circuits.
Note that all node voltages are referenced to
the ground node.
©2001, John Wiley & Sons, Inc.
Introduction To Electric Circuits, 5th Ed
Chapter 6: The Operational Amplifier
Figure 6.6-1
(cont.)
A brief catalog of
operational amplifier
circuits.
©2001, John Wiley & Sons, Inc.
Introduction To Electric Circuits, 5th Ed
Chapter 6: The Operational Amplifier
Figure 6.6-1
(cont.)
A brief catalog of
operational
amplifier circuits.
©2001, John Wiley & Sons, Inc.
Introduction To Electric Circuits, 5th Ed
Chapter 6: The Operational Amplifier
Figure 6.6-2
Circuit #1
(a) before and
(b) after Circuit #2
is connected.
(c) Preventing
loading using a
voltage follower.
©2001, John Wiley & Sons, Inc.
Introduction To Electric Circuits, 5th Ed
Figure 6.6-3
Chapter 6: The Operational Amplifier
A voltage divider (a) before and (b) after a 30-k
resistor is added. (c) A voltage follower is added
to prevent loading.
©2001, John Wiley & Sons, Inc.
Introduction To Electric Circuits, 5th Ed
Chapter 6: The Operational Amplifier
Figure 6.6-4
(a) An amplifier is
required to make
νo  Kνin. The
choice of amplifier
circuit depends on
the value of the
gain K. Four
cases are
shown:(b) K  5,
(c) K  5, (d) K =
1, and (e) K = 0.8.
©2001, John Wiley & Sons, Inc.
Introduction To Electric Circuits, 5th Ed
Figure 6.6-5
Chapter 6: The Operational Amplifier
The proposed noninverting summing
amplifier.
©2001, John Wiley & Sons, Inc.
Introduction To Electric Circuits, 5th Ed
Chapter 6: The Operational Amplifier
Figure 6.6-6
The final design of the noninverting
summing amplifier.
©2001, John Wiley & Sons, Inc.
Introduction To Electric Circuits, 5th Ed
Chapter 6: The Operational Amplifier
Figure 6.6-7
The spreadsheet for all standard values of
r1 and rf.
©2001, John Wiley & Sons, Inc.
Introduction To Electric Circuits, 5th Ed
Figure 6.7-1
Chapter 6: The Operational Amplifier
(a) An operational amplifier and (b) the offsets model of an
operational amplifier. (c) The finite gain model of an
operational amplifier. (d) The offsets and finite gain model
of an operational amplifier.
©2001, John Wiley & Sons, Inc.
Introduction To Electric Circuits, 5th Ed
Figure 6.7-2
Chapter 6: The Operational Amplifier
(a) An inverting amplifier and (b) an equivalent circuit
that accounts for the input offset voltage and bias
currents of the operational amplifier. (c) -(f) Analysis
using superposition.
©2001, John Wiley & Sons, Inc.
Introduction To Electric Circuits, 5th Ed
Chapter 6: The Operational Amplifier
Figure 6.7-3
(a) A voltage follower used as a buffer amplifier and (b)
an equivalent circuit with the operational amplifier model
that accounts for finite voltage gain.
©2001, John Wiley & Sons, Inc.
Introduction To Electric Circuits, 5th Ed
Chapter 6: The Operational Amplifier
Figure E 6.7-4
©2001, John Wiley & Sons, Inc.
Introduction To Electric Circuits, 5th Ed
Chapter 6: The Operational Amplifier
Figure 6.8-1
(a) A circuit using
operational
amplifiers and
(b) a PSpice
model of a
typical μA741
operational
amplifier.
©2001, John Wiley & Sons, Inc.
Introduction To Electric Circuits, 5th Ed
Chapter 6: The Operational Amplifier
Figure 6.8-2
PSpice input file
for the summing
amplifier.
©2001, John Wiley & Sons, Inc.
Introduction To Electric Circuits, 5th Ed
Chapter 6: The Operational Amplifier
Figure 6.8-3
PSpice list
showing
substitution of
subcircuits.
©2001, John Wiley & Sons, Inc.
Introduction To Electric Circuits, 5th Ed
Chapter 6: The Operational Amplifier
Figure 6.8-4
PSpice output for the summing amplifier.
©2001, John Wiley & Sons, Inc.
Introduction To Electric Circuits, 5th Ed
Chapter 6: The Operational Amplifier
Figure 6.9-1
An inverting amplifier.
©2001, John Wiley & Sons, Inc.
Introduction To Electric Circuits, 5th Ed
Chapter 6: The Operational Amplifier
Figure 6.9-2
MATLAB input file
corresponding to
the circuit shown
in Figure 6.9-1.
©2001, John Wiley & Sons, Inc.
Introduction To Electric Circuits, 5th Ed
Chapter 6: The Operational Amplifier
Figure 6.9-3
Plots of the input and output voltages of
the circuit shown in Figure 6.9-1.
©2001, John Wiley & Sons, Inc.
Introduction To Electric Circuits, 5th Ed
Chapter 6: The Operational Amplifier
Figure 6.10-1
(a) An example circuit and (b) computer
analysis using MathCad.
©2001, John Wiley & Sons, Inc.
Introduction To Electric Circuits, 5th Ed
Chapter 6: The Operational Amplifier
Figure 6.11-1
Interfacing a pressure transducer with an
analog-to-digital converter (ADC).
©2001, John Wiley & Sons, Inc.
Introduction To Electric Circuits, 5th Ed
Chapter 6: The Operational Amplifier
Figure 6.11-2
A structure (or plan) for the interface
circuit.
©2001, John Wiley & Sons, Inc.
Introduction To Electric Circuits, 5th Ed
Chapter 6: The Operational Amplifier
Figure 6.11-3
One implementation of the interface
circuit.
©2001, John Wiley & Sons, Inc.
Introduction To Electric Circuits, 5th Ed
Chapter 6: The Operational Amplifier
Figure 6.11-4
PSpice simulation of the circuit shown in
Figure 6.11-3.
©2001, John Wiley & Sons, Inc.
Introduction To Electric Circuits, 5th Ed