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Электронный компонент: CA3140AM96

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1
CA3140, CA3140A
4.5MHz, BiMOS Operational Amplifier with
MOSFET Input/Bipolar Output
The CA3140A and CA3140 are integrated circuit operational
amplifiers that combine the advantages of high voltage
PMOS transistors with high voltage bipolar transistors on a
single monolithic chip.
The CA3140A and CA3140 BiMOS operational amplifiers
feature gate protected MOSFET (PMOS) transistors in the
input circuit to provide very high input impedance, very low
input current, and high speed performance. The CA3140A
and CA3140 operate at supply voltage from 4V to 36V
(either single or dual supply). These operational amplifiers
are internally phase compensated to achieve stable
operation in unity gain follower operation, and additionally,
have access terminal for a supplementary external capacitor
if additional frequency roll-off is desired. Terminals are also
provided for use in applications requiring input offset voltage
nulling. The use of PMOS field effect transistors in the input
stage results in common mode input voltage capability down
to 0.5V below the negative supply terminal, an important
attribute for single supply applications. The output stage
uses bipolar transistors and includes built-in protection
against damage from load terminal short circuiting to either
supply rail or to ground.
The CA3140A and CA3140 are intended for operation at
supply voltages up to 36V (
18V).
Features
MOSFET Input Stage
- Very High Input Impedance (Z
IN
) -1.5T
(Typ)
- Very Low Input Current (I
l
) -10pA (Typ) at
15V
- Wide Common Mode Input Voltage Range (V
lCR
) - Can
be Swung 0.5V Below Negative Supply Voltage Rail
- Output Swing Complements Input Common Mode
Range
Directly Replaces Industry Type 741 in Most
Applications
Applications
Ground-Referenced Single Supply Amplifiers in
Automobile and Portable Instrumentation
Sample and Hold Amplifiers
Long Duration Timers/Multivibrators
(
seconds-Minutes-Hours)
Photocurrent Instrumentation
Peak Detectors
Active Filters
Comparators
Interface in 5V TTL Systems and Other Low
Supply Voltage Systems
All Standard Operational Amplifier Applications
Function Generators
Tone Controls
Power Supplies
Portable Instruments
Intrusion Alarm Systems
Pinout
CA3140 (PDIP, SOIC)
TOP VIEW
Ordering Information
PART NUMBER
(BRAND)
TEMP.
RANGE (
o
C)
PACKAGE
PKG.
NO.
CA3140AE
-55 to 125
8 Ld PDIP
E8.3
CA3140AM
(3140A)
-55 to 125
8 Ld SOIC
M8.15
CA3140E
-55 to 125
8 Ld PDIP
E8.3
CA3140M
(3140)
-55 to 125
8 Ld SOIC
M8.15
CA3140M96
(3140)
-55 to 125
8 Ld SOIC Tape and Reel
INV. INPUT
NON-INV.
V-
1
2
3
4
8
7
6
5
STROBE
V+
OUTPUT
OFFSET
NULL
OFFSET
NULL
INPUT
-
+
Data Sheet
November 2002
FN957.7
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1-888-INTERSIL or 321-724-7143
|
Intersil (and design) is a registered trademark of Intersil Americas Inc.
Copyright Intersil Americas Inc. 2002. All Rights Reserved
All other trademarks mentioned are the property of their respective owners.
2
Absolute Maximum Ratings
Thermal Information
DC Supply Voltage (Between V+ and V- Terminals) . . . . . . . . . 36V
Differential Mode Input Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . 8V
DC Input Voltage . . . . . . . . . . . . . . . . . . . . . (V+
+8V) To (V- -0.5V)
Input Terminal Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1mA
Output Short Circuit Duration
(Note 2) . . . . . . . . . . . . . . Indefinite
Operating Conditions
Temperature Range. . . . . . . . . . . . . . . . . . . . . . . . . -55
o
C to 125
o
C
Thermal Resistance (Typical, Note 1)
JA
(
o
C/W)
JC
(
o
C/W)
PDIP Package . . . . . . . . . . . . . . . . . . .
115
N/A
SOIC Package . . . . . . . . . . . . . . . . . . .
165
N/A
Maximum Junction Temperature (Plastic Package) . . . . . . . 150
o
C
Maximum Storage Temperature Range . . . . . . . . . -65
o
C to 150
o
C
Maximum Lead Temperature (Soldering 10s) . . . . . . . . . . . . 300
o
C
(SOIC - Lead Tips Only)
CAUTION: Stresses above those listed in "Absolute Maximum Ratings" may cause permanent damage to the device. This is a stress only rating and operation of the
device at these or any other conditions above those indicated in the operational sections of this specification is not implied.
NOTES:
1.
JA
is measured with the component mounted on a low effective thermal conductivity test board in free air. See Tech Brief TB379 for details
2. Short circuit may be applied to ground or to either supply.
Electrical Specifications
V
SUPPLY
=
15V, T
A
= 25
o
C
PARAMETER
SYMBOL
TEST CONDITIONS
TYPICAL VALUES
UNITS
CA3140
CA3140A
Input Offset Voltage Adjustment Resistor
Typical Value of Resistor
Between Terminals 4 and 5 or 4 and 1 to
Adjust Max V
IO
4.7
18
k
Input Resistance
R
I
1.5
1.5
T
Input Capacitance
C
I
4
4
pF
Output Resistance
R
O
60
60
Equivalent Wideband Input Noise Voltage
(See Figure 27)
e
N
BW = 140kHz, R
S
= 1M
48
48
V
Equivalent Input Noise Voltage (See Figure 35)
e
N
R
S
= 100
f = 1kHz
40
40
nV/
Hz
f = 10kHz
12
12
nV/
Hz
Short Circuit Current to Opposite Supply
I
OM
+
Source
40
40
mA
I
OM
-
Sink
18
18
mA
Gain-Bandwidth Product, (See Figures 6, 30)
f
T
4.5
4.5
MHz
Slew Rate, (See Figure 31)
SR
9
9
V/
s
Sink Current From Terminal 8 To Terminal 4 to
Swing Output Low
220
220
A
Transient Response (See Figure 28)
t
r
R
L
= 2k
C
L
= 100pF
Rise Time
0.08
0.08
s
OS
Overshoot
10
10
%
Settling Time at 10V
P-P
, (See Figure 5)
t
S
R
L
= 2k
C
L
= 100pF
Voltage Follower
To 1mV
4.5
4.5
s
To 10mV
1.4
1.4
s
Electrical Specifications
For Equipment Design, at V
SUPPLY
=
15V, T
A
= 25
o
C, Unless Otherwise Specified
PARAMETER
SYMBOL
CA3140
CA3140A
UNITS
MIN
TYP
MAX
MIN
TYP
MAX
Input Offset Voltage
|V
IO
|
-
5
15
-
2
5
mV
Input Offset Current
|I
IO
|
-
0.5
30
-
0.5
20
pA
Input Current
I
I
-
10
50
-
10
40
pA
Large Signal Voltage Gain (Note 3)
(See Figures 6, 29)
A
OL
20
100
-
20
100
-
kV/V
86
100
- 86
100
-
dB
CA3140, CA3140A
3
Common Mode Rejection Ratio
(See Figure 34)
CMRR
-
32
320
-
32
320
V/V
70
90
-
70
90
-
dB
Common Mode Input Voltage Range (See Figure 8)
V
ICR
-15
-15.5 to +12.5
11
-15
-15.5 to +12.5
12
V
Power-Supply Rejection Ratio,
V
IO
/
V
S
(See Figure 36)
PSRR
-
100
150
-
100
150
V/V
76
80
-
76
80
-
dB
Max Output Voltage (Note 4)
(See Figures 2, 8)
V
OM
+
+12
13
-
+12
13
-
V
V
OM
-
-14
-14.4
-
-14
-14.4
-
V
Supply Current (See Figure 32)
I+
-
4
6
-
4
6
mA
Device Dissipation
P
D
-
120
180 -
120
180
mW
Input Offset Voltage Temperature Drift
V
IO
/
T
-
8
-
-
6
-
V/
o
C
NOTES:
3. At V
O
= 26V
P-P
, +12V, -14V and R
L
= 2k
.
4. At R
L
= 2k
.
Electrical Specifications
For Equipment Design, at V
SUPPLY
=
15V, T
A
= 25
o
C, Unless Otherwise Specified (Continued)
PARAMETER
SYMBOL
CA3140
CA3140A
UNITS
MIN
TYP
MAX
MIN
TYP
MAX
Electrical Specifications
For Design Guidance At V+ = 5V, V- = 0V, T
A
= 25
o
C
PARAMETER
SYMBOL
TYPICAL VALUES
UNITS
CA3140
CA3140A
Input Offset Voltage
|V
IO
|
5
2
mV
Input Offset Current
|I
IO
|
0.1
0.1
pA
Input Current
I
I
2
2
pA
Input Resistance
R
I
1
1
T
Large Signal Voltage Gain (See Figures 6, 29)
A
OL
100
100
kV/V
100
100
dB
Common Mode Rejection Ratio
CMRR
32
32
V/V
90
90
dB
Common Mode Input Voltage Range (See Figure 8)
V
ICR
-0.5
-0.5
V
2.6
2.6
V
Power Supply Rejection Ratio
PSRR
V
IO
/
V
S
100
100
V/V
80
80
dB
Maximum Output Voltage (See Figures 2, 8)
V
OM
+
3
3
V
V
OM
-
0.13
0.13
V
Maximum Output Current:
Source
I
OM
+
10
10
mA
Sink
I
OM
-
1
1
mA
Slew Rate (See Figure 31)
SR
7
7
V/
s
Gain-Bandwidth Product (See Figure 30)
f
T
3.7
3.7
MHz
Supply Current (See Figure 32)
I+
1.6
1.6
mA
Device Dissipation
P
D
8
8
mW
Sink Current from Terminal 8 to Terminal 4 to Swing Output Low
200
200
A
CA3140, CA3140A
4
Block Diagram
Schematic Diagram
A
10
A
10,000
C
1
12pF
5
A
1
1
8
4
6
7
2
3
OFFSET
STROBE
NULL
OUTPUT
INPUT
+
-
200
A
200
A
1.6mA
2
A
2mA
2mA
4mA
V+
V-
BIAS CIRCUIT
CURRENT SOURCES
AND REGULATOR
R
5
500
R
4
500
Q
11
Q
12
R
2
500
R
3
500
Q
10
Q
9
D
5
D
4
D
3
5
1
8
STROBE
OFFSET NULL
3
2
NON-INVERTING
INPUT
INVERTING
INPUT
+
-
C
1
12pF
Q
13
Q
15
Q
16
Q
21
Q
20
D
8
Q
19
Q
18
Q
17
R
11
20
R
9
50
R
8
1K
R
12
12K
R
14
20K
R
13
5K
D
7
R
10
1K
OUTPUT
D
6
4
V-
V+
6
7
DYNAMIC CURRENT SINK
OUTPUT STAGE
SECOND STAGE
INPUT STAGE
BIAS CIRCUIT
D
2
Q
8
Q
4
Q
3
Q
5
Q
2
Q
6
Q
7
D
1
Q
1
R
1
8K
Q
14
R
7
30
R
6
50
NOTE: All resistance values are in ohms.
CA3140, CA3140A
5
Application Information
Circuit Description
As shown in the block diagram, the input terminals may be
operated down to 0.5V below the negative supply rail. Two
class A amplifier stages provide the voltage gain, and a
unique class AB amplifier stage provides the current gain
necessary to drive low-impedance loads.
A biasing circuit provides control of cascoded constant current
flow circuits in the first and second stages. The CA3140
includes an on chip phase compensating capacitor that is
sufficient for the unity gain voltage follower configuration.
Input Stage
The schematic diagram consists of a differential input stage
using PMOS field-effect transistors (Q
9
, Q
10
) working into a
mirror pair of bipolar transistors (Q
11
, Q
12
) functioning as load
resistors together with resistors R
2
through R
5
. The mirror pair
transistors also function as a differential-to-single-ended
converter to provide base current drive to the second stage
bipolar transistor (Q
13
). Offset nulling, when desired, can be
effected with a 10k
potentiometer connected across
Terminals 1 and 5 and with its slider arm connected to Terminal
4. Cascode-connected bipolar transistors Q
2
, Q
5
are the
constant current source for the input stage. The base biasing
circuit for the constant current source is described
subsequently. The small diodes D
3
, D
4
, D
5
provide gate oxide
protection against high voltage transients, e.g., static electricity.
Second Stage
Most of the voltage gain in the CA3140 is provided by the
second amplifier stage, consisting of bipolar transistor Q
13
and its cascode connected load resistance provided by
bipolar transistors Q
3
, Q
4
. On-chip phase compensation,
sufficient for a majority of the applications is provided by C
1
.
Additional Miller-Effect compensation (roll off) can be
accomplished, when desired, by simply connecting a small
capacitor between Terminals 1 and 8. Terminal 8 is also
used to strobe the output stage into quiescence. When
terminal 8 is tied to the negative supply rail (Terminal 4) by
mechanical or electrical means, the output Terminal 6
swings low, i.e., approximately to Terminal 4 potential.
Output Stage
The CA3140 Series circuits employ a broad band output stage
that can sink loads to the negative supply to complement the
capability of the PMOS input stage when operating near the
negative rail. Quiescent current in the emitter-follower cascade
circuit (Q
17
, Q
18
) is established by transistors (Q
14
, Q
15
)
whose base currents are "mirrored" to current flowing through
diode D
2
in the bias circuit section. When the CA3140 is
operating such that output Terminal 6 is sourcing current,
transistor Q
18
functions as an emitter-follower to source current
from the V+ bus (Terminal 7), via D
7
, R
9
, and R
11
. Under these
conditions, the collector potential of Q
13
is sufficiently high to
permit the necessary flow of base current to emitter follower
Q
17
which, in turn, drives Q
18
.
When the CA3140 is operating such that output Terminal 6 is
sinking current to the V- bus, transistor Q
16
is the current
sinking element. Transistor Q
16
is mirror connected to D
6
, R
7
,
with current fed by way of Q
21
, R
12
, and Q
20
. Transistor Q
20
,
in turn, is biased by current flow through R
13
, zener D
8
, and
R
14
. The dynamic current sink is controlled by voltage level
sensing. For purposes of explanation, it is assumed that output
Terminal 6 is quiescently established at the potential midpoint
between the V+ and V- supply rails. When output current
sinking mode operation is required, the collector potential of
transistor Q
13
is driven below its quiescent level, thereby
causing Q
17
, Q
18
to decrease the output voltage at Terminal 6.
Thus, the gate terminal of PMOS transistor Q
21
is displaced
toward the V- bus, thereby reducing the channel resistance of
Q
21
. As a consequence, there is an incremental increase in
current flow through Q
20
, R
12
, Q
21
, D
6
, R
7
, and the base of
Q
16
. As a result, Q
16
sinks current from Terminal 6 in direct
response to the incremental change in output voltage caused
by Q
18
. This sink current flows regardless of load; any excess
current is internally supplied by the emitter-follower Q
18
. Short
circuit protection of the output circuit is provided by Q
19
, which
is driven into conduction by the high voltage drop developed
across R
11
under output short circuit conditions. Under these
conditions, the collector of Q
19
diverts current from Q
4
so as to
reduce the base current drive from Q
17
, thereby limiting current
flow in Q
18
to the short circuited load terminal.
Bias Circuit
Quiescent current in all stages (except the dynamic current
sink) of the CA3140 is dependent upon bias current flow in R
1
.
The function of the bias circuit is to establish and maintain
constant current flow through D
1
, Q
6
, Q
8
and D
2
. D
1
is a diode
connected transistor mirror connected in parallel with the base
emitter junctions of Q
1
, Q
2
, and Q
3
. D
1
may be considered as a
current sampling diode that senses the emitter current of Q
6
and automatically adjusts the base current of Q
6
(via Q
1
) to
maintain a constant current through Q
6
, Q
8
, D
2
. The base
currents in Q
2
, Q
3
are also determined by constant current flow
D
1
. Furthermore, current in diode connected transistor Q
2
establishes the currents in transistors Q
14
and Q
15
.
Typical Applications
Wide dynamic range of input and output characteristics with
the most desirable high input impedance characteristics is
achieved in the CA3140 by the use of an unique design based
upon the PMOS Bipolar process. Input common mode voltage
range and output swing capabilities are complementary,
allowing operation with the single supply down to 4V.
The wide dynamic range of these parameters also means
that this device is suitable for many single supply
applications, such as, for example, where one input is driven
below the potential of Terminal 4 and the phase sense of the
output signal must be maintained a most important
consideration in comparator applications.
CA3140, CA3140A
6
Output Circuit Considerations
Excellent interfacing with TTL circuitry is easily achieved
with a single 6.2V zener diode connected to Terminal 8 as
shown in Figure 1. This connection assures that the
maximum output signal swing will not go more positive than
the zener voltage minus two base-to-emitter voltage drops
within the CA3140. These voltages are independent of the
operating supply voltage.
Figure 2 shows output current sinking capabilities of the
CA3140 at various supply voltages. Output voltage swing to
the negative supply rail permits this device to operate both
power transistors and thyristors directly without the need for
level shifting circuitry usually associated with the 741 series
of operational amplifiers.
Figure 4 shows some typical configurations. Note that a
series resistor, R
L
, is used in both cases to limit the drive
available to the driven device. Moreover, it is recommended
that a series diode and shunt diode be used at the thyristor
input to prevent large negative transient surges that can
appear at the gate of thyristors, from damaging the
integrated circuit.
Offset Voltage Nulling
The input offset voltage can be nulled by connecting a 10k
potentiometer between Terminals 1 and 5 and returning its
wiper arm to terminal 4, see Figure 3A. This technique,
however, gives more adjustment range than required and
therefore, a considerable portion of the potentiometer
rotation is not fully utilized. Typical values of series resistors
(R) that may be placed at either end of the potentiometer,
see Figure 3B, to optimize its utilization range are given in
the Electrical Specifications table.
An alternate system is shown in Figure 3C. This circuit uses
only one additional resistor of approximately the value
shown in the table. For potentiometers, in which the
resistance does not drop to 0
at either end of rotation, a
value of resistance 10% lower than the values shown in the
table should be used.
Low Voltage Operation
Operation at total supply voltages as low as 4V is possible
with the CA3140. A current regulator based upon the PMOS
threshold voltage maintains reasonable constant operating
current and hence consistent performance down to these
lower voltages.
The low voltage limitation occurs when the upper extreme of
the input common mode voltage range extends down to the
voltage at Terminal 4. This limit is reached at a total supply
voltage just below 4V. The output voltage range also begins to
extend down to the negative supply rail, but is slightly higher
than that of the input. Figure 8 shows these characteristics and
shows that with 2V dual supplies, the lower extreme of the input
common mode voltage range is below ground potential.
3
2
4
CA3140
8
6
7
V+
5V TO 36V
6.2V
5V
LOGIC
SUPPLY
5V
TYPICAL
TTL GATE
FIGURE 1. ZENER CLAMPING DIODE CONNECTED TO
TERMINALS 8 AND 4 TO LIMIT CA3140 OUTPUT
SWING TO TTL LEVELS
1
0.01
0.1
LOAD (SINKING) CURRENT (mA)
1.0
10
10
100
1000
OUT
P
UT
ST
AGE T
RANSIST
O
R (
Q
15
, Q
16
)
SAT
URAT
ION VOL
T
A
GE (
m
V)
SUPPLY VOLTAGE (V-) = 0V
T
A
= 25
o
C
SUPPLY VOLTAGE (V+) = +5V
+15V
+30V
FIGURE 2. VOLTAGE ACROSS OUTPUT TRANSISTORS (Q
15
AND Q
16
) vs LOAD CURRENT
FIGURE 3A. BASIC
FIGURE 3B. IMPROVED RESOLUTION
FIGURE 3C. SIMPLER IMPROVED RESOLUTION
FIGURE 3. THREE OFFSET VOLTAGE NULLING METHODS
3
2
4
CA3140
7
6
V+
5
1
V-
10k
3
2
4
CA3140
7
6
V+
5
1
V-
10k
R
R
3
2
4
CA3140
7
6
V+
5
1
V-
10k
R
CA3140, CA3140A
7
Bandwidth and Slew Rate
For those cases where bandwidth reduction is desired, for
example, broadband noise reduction, an external capacitor
connected between Terminals 1 and 8 can reduce the open
loop -3dB bandwidth. The slew rate will, however, also be
proportionally reduced by using this additional capacitor.
Thus, a 20% reduction in bandwidth by this technique will
also reduce the slew rate by about 20%.
Figure 5 shows the typical settling time required to reach
1mV or 10mV of the final value for various levels of large
signal inputs for the voltage follower and inverting unity gain
amplifiers.
The exceptionally fast settling time characteristics are largely
due to the high combination of high gain and wide bandwidth
of the CA3140; as shown in Figure 6.
Input Circuit Considerations
As mentioned previously, the amplifier inputs can be driven
below the Terminal 4 potential, but a series current limiting
resistor is recommended to limit the maximum input terminal
current to less than 1mA to prevent damage to the input
protection circuitry.
Moreover, some current limiting resistance should be
provided between the inverting input and the output when
FIGURE 4. METHODS OF UTILIZING THE V
CE(SAT)
SINKING CURRENT CAPABILITY OF THE CA3140 SERIES
3
2
4
CA3140
7
6
LOAD
R
L
R
S
MT
2
MT
1
30V
NO LOAD
120V
AC
3
2
4
CA3140
7
6
V+
+HV
LOAD
R
L
FIGURE 5A. WAVEFORM
FIGURE 5B. TEST CIRCUITS
FIGURE 5. SETTLING TIME vs INPUT VOLTAGE
SETTLING TIME (
s)
0.1
I
N
P
U
T
VO
LTA
G
E
(
V
)
1.0
10
SUPPLY VOLTAGE: V
S
=
15V
T
A
= 25
o
C
1mV
10mV
10mV
1mV
1mV
1mV
10mV
FOLLOWER
INVERTING
LOAD RESISTANCE (R
L
) = 2k
LOAD CAPACITANCE (C
L
) = 100pF
10
8
6
4
2
0
-2
-4
-6
-8
-10
10mV
3
2
CA3140
6
SIMULATED
LOAD
4
-15V
0.1
F
5.11k
0.1
F
7
+15V
5k
2k
100pF
5k
INVERTING
SETTLING POINT
200
4.99k
D
1
1N914
D
2
1N914
2
CA3140
6
SIMULATED
LOAD
4
-15V
0.1
F
0.1
F
7
+15V
2k
100pF
0.05
F
2k
3
10k
FOLLOWER
CA3140, CA3140A
8
the CA3140 is used as a unity gain voltage follower. This
resistance prevents the possibility of extremely large input
signal transients from forcing a signal through the input
protection network and directly driving the internal constant
current source which could result in positive feedback via the
output terminal. A 3.9k
resistor is sufficient.
The typical input current is on the order of 10pA when the
inputs are centered at nominal device dissipation. As the
output supplies load current, device dissipation will increase,
raising the chip temperature and resulting in increased input
current. Figure 7 shows typical input terminal current versus
ambient temperature for the CA3140.
It is well known that MOSFET devices can exhibit slight
changes in characteristics (for example, small changes in
input offset voltage) due to the application of large
differential input voltages that are sustained over long
periods at elevated temperatures.
Both applied voltage and temperature accelerate these
changes. The process is reversible and offset voltage shifts of
the opposite polarity reverse the offset. Figure 9 shows the
typical offset voltage change as a function of various stress
voltages at the maximum rating of 125
o
C (for metal can); at
lower temperatures (metal can and plastic), for example, at
85
o
C, this change in voltage is considerably less. In typical
linear applications, where the differential voltage is small and
symmetrical, these incremental changes are of about the
same magnitude as those encountered in an operational
amplifier employing a bipolar transistor input stage.
FIGURE 6. OPEN LOOP VOLTAGE GAIN AND PHASE vs
FREQUENCY
FIGURE 7. INPUT CURRENT vs TEMPERATURE
FIGURE 8. OUTPUT VOLTAGE SWING CAPABILITY AND COMMON MODE INPUT VOLTAGE RANGE vs SUPPLY VOLTAGE
10
1
10
3
10
4
10
5
10
6
10
7
10
8
FREQUENCY (Hz)
O
PEN L
OO
P V
O
LT
A
G
E
G
AIN
(
dB
)
100
80
60
40
20
0
SUPPLY VOLTAGE: V
S
=
15V
T
A
= 25
o
C
10
2
OP
E
N
L
O
OP

P
H
A
S
E
-75
-90
-105
-120
-135
-150
(
D
EG
REES
)
R
L
= 2k
,
C
L
= 0pF
R
L
= 2k
,
C
L
= 100pF
OL
SUPPLY VOLTAGE: V
S
=
15V
TEMPERATURE (
o
C)
-60
-40
-20
0
20
40
60
80
100 120
140
INPUT
CU
RRE
N
T
(
p
A)
1K
100
1
10K
10
SUPPLY VOLTAGE (V+, V-)
0
5
10
15
20
25
-1.5
-2.0
-1.0
-2.5
R
L
=
+V
OUT
AT T
A
= 125
o
C
+V
OUT
AT T
A
= 25
o
C
+V
OUT
AT T
A
= -55
o
C
+V
ICR
AT T
A
= 125
o
C
+V
ICR
AT T
A
= 25
o
C
+V
ICR
AT T
A
= -55
o
C
-3.0
0
-0.5
INPUT
AND
O
UT
PUT
V
O
LT
A
G
E EX
C
UR
S
I
O
N
S
F
R
OM
T
E
RM
INAL
7
(
V
+)
SUPPLY VOLTAGE (V+, V-)
0
5
10
15
20
25
-V
ICR
AT T
A
= 125
o
C
-V
ICR
AT T
A
= 25
o
C
-V
ICR
AT T
A
= -55
o
C
-V
OUT
FOR
T
A
= -55
o
C to 125
o
C
INPUT
AND
OUT
P
UT
VOL
T
AG
E EXCURSIONS
F
R
O
M
T
E
RM
I
NAL
4
(
V
-
)
0
-0.5
0.5
-1.0
-1.5
1.5
1.0
CA3140, CA3140A
9
Super Sweep Function Generator
A function generator having a wide tuning range is shown in
Figure 10. The 1,000,000/1 adjustment range is
accomplished by a single variable potentiometer or by an
auxiliary sweeping signal. The CA3140 functions as a non-
inverting readout amplifier of the triangular signal developed
across the integrating capacitor network connected to the
output of the CA3080A current source.
Buffered triangular output signals are then applied to a
second CA3080 functioning as a high speed hysteresis
switch. Output from the switch is returned directly back to the
input of the CA3080A current source, thereby, completing
the positive feedback loop
The triangular output level is determined by the four 1N914
level limiting diodes of the second CA3080 and the resistor
divider network connected to Terminal No. 2 (input) of the
CA3080. These diodes establish the input trip level to this
switching stage and, therefore, indirectly determine the
amplitude of the output triangle.
Compensation for propagation delays around the entire loop
is provided by one adjustment on the input of the CA3080.
This adjustment, which provides for a constant generator
amplitude output, is most easily made while the generator is
sweeping. High frequency ramp linearity is adjusted by the
single 7pF to 60pF capacitor in the output of the CA3080A.
It must be emphasized that only the CA3080A is
characterized for maximum output linearity in the current
generator function.
Meter Driver and Buffer Amplifier
Figure 11 shows the CA3140 connected as a meter driver
and buffer amplifier. Low driving impedance is required of
the CA3080A current source to assure smooth operation of
the Frequency Adjustment Control. This low-driving
impedance requirement is easily met by using a CA3140
connected as a voltage follower. Moreover, a meter may be
placed across the input to the CA3080A to give a logarithmic
analog indication of the function generator's frequency.
Analog frequency readout is readily accomplished by the
means described above because the output current of the
CA3080A varies approximately one decade for each 60mV
change in the applied voltage, V
ABC
(voltage between
Terminals 5 and 4 of the CA3080A of the function generator).
Therefore, six decades represent 360mV change in V
ABC
.
Now, only the reference voltage must be established to set
the lower limit on the meter. The three remaining transistors
from the CA3086 Array used in the sweep generator are
used for this reference voltage. In addition, this reference
generator arrangement tends to track ambient temperature
variations, and thus compensates for the effects of the
normal negative temperature coefficient of the CA3080A
V
ABC
terminal voltage.
Another output voltage from the reference generator is used
to insure temperature tracking of the lower end of the
Frequency Adjustment Potentiometer. A large series
resistance simulates a current source, assuring similar
temperature coefficients at both ends of the Frequency
Adjustment Control.
To calibrate this circuit, set the Frequency Adjustment
Potentiometer at its low end. Then adjust the Minimum
Frequency Calibration Control for the lowest frequency. To
establish the upper frequency limit, set the Frequency
Adjustment Potentiometer to its upper end and then adjust
the Maximum Frequency Calibration Control for the
maximum frequency. Because there is interaction among
these controls, repetition of the adjustment procedure may
be necessary. Two adjustments are used for the meter. The
meter sensitivity control sets the meter scale width of each
decade, while the meter position control adjusts the pointer
on the scale with negligible effect on the sensitivity
adjustment. Thus, the meter sensitivity adjustment control
calibrates the meter so that it deflects
1
/
6
of full scale for
each decade change in frequency.
Sine Wave Shaper
The circuit shown in Figure 12 uses a CA3140 as a voltage
follower in combination with diodes from the CA3019 Array
to convert the triangular signal from the function generator to
a sine-wave output signal having typically less than 2%
THD. The basic zero crossing slope is established by the
10k
potentiometer connected between Terminals 2 and 6
of the CA3140 and the 9.1k
resistor and 10k
potentiometer from Terminal 2 to ground. Two break points
are established by diodes D
1
through D
4
. Positive feedback
via D
5
and D
6
establishes the zero slope at the maximum
and minimum levels of the sine wave. This technique is
necessary because the voltage follower configuration
approaches unity gain rather than the zero gain required to
shape the sine wave at the two extremes.
7
6
5
4
3
2
0
O
F
F
SET VO
LT
AG
E

S
H
I
F
T (
m
V)
0
500 1000 1500 2000 2500 3000 3500 4000 4500
TIME (HOURS)
1
DIFFERENTIAL DC VOLTAGE
(ACROSS TERMINALS 2 AND 3) = 0V
OUTPUT VOLTAGE = V+ / 2
T
A
= 125
o
C
FOR METAL CAN PACKAGES
DIFFERENTIAL DC VOLTAGE
(ACROSS TERMINALS 2 AND 3) = 2V
OUTPUT STAGE TOGGLED
FIGURE 9. TYPICAL INCREMENTAL OFFSET VOLTAGE
SHIFT vs OPERATING LIFE
CA3140, CA3140A
10
FIGURE 10A. CIRCUIT
Top Trace: Output at junction of 2.7
and 51
resistors;
5V/Div., 500ms/Div.
Center Trace: External output of triangular function generator;
2V/Div., 500ms/Div.
Bottom Trace: Output of "Log" generator; 10V/Div., 500ms/Div.
FIGURE 10B. FIGURE FUNCTION GENERATOR SWEEPING
1V/Div., 1s/Div.
Three tone test signals, highest frequency
0.5MHz. Note the slight
asymmetry at the three second/cycle signal. This asymmetry is due to
slightly different positive and negative integration from the CA3080A
and from the PC board and component leakages at the 100pA level.
FIGURE 10C. FUNCTION GENERATOR WITH FIXED
FREQUENCIES
FIGURE 10D. INTERCONNECTIONS
FIGURE 10. FUNCTION GENERATOR
0.1
F
1N914
6
7
4
2
3
0.1
F
5.1k
10k
2.7k
6
7
4
2
5
-15V
13k
+15V
CENTERING
10k
-15V
910k
62k
11k
10k
EXTERNAL
OUTPUT
11k
HIGH
FREQUENCY
LEVEL
7-60pF
EXTERNAL
OUTPUT
TO OUTPUT
AMPLIFIER
OUTPUT
AMPLIFIER
TO
SINE WAVE
SHAPER
2k
FREQUENCY
ADJUSTMENT
HIGH
FREQ.
SHAPE
SYMMETRY
THIS NETWORK IS USED WHEN THE
OPTIONAL BUFFER CIRCUIT IS NOT USED
-15V
+15V
10k
120
39k
100k
3
6
3
2
4
7
7.5k
+15V
+15V
15k
360
360
2M
7-60
pF
-15V
-15V
+15V
51
pF
+
CA3080A
-
CA3140
CA3080
+
-
+
-
5
-15V
FROM BUFFER METER
DRIVER (OPTIONAL)
FREQUENCY
ADJUSTMENT
METER DRIVER
AND BUFFER
AMPLIFIER
FUNCTION
GENERATOR
SINE WAVE
SHAPER
M
POWER
SUPPLY
15V
-15V
+15V
DC LEVEL
ADJUST
51
WIDEBAND
LINE DRIVER
SWEEP
GENERATOR
GATE
SWEEP
V-
SWEEP
LENGTH
EXTERNAL
INPUT
OFF
V-
COARSE
RATE
FINE
RATE
EXT.
INT.
CA3140, CA3140A
11
FIGURE 11. METER DRIVER AND BUFFER AMPLIFIER
FIGURE 12. SINE WAVE SHAPER
FIGURE 13. SWEEPING GENERATOR
FREQUENCY
CALIBRATION
MINIMUM
200
A
METER
FREQUENCY
CALIBRATION
MAXIMUM
METER
SENSITIVITY
ADJUSTMENT
METER
POSITION
ADJUSTMENT
CA3080A
6
3
2
4
7
+
CA3140
-
FREQUENCY
ADJUSTMENT
10k
620
4.7k
0.1
F
12k
2k
500k
620k
51k
3M
510
510
2k
3.6k
-15V
M
11
14
13
3
/
5
OF CA3086
5
4
TO CA3080A
OF FUNCTION
GENERATOR
(FIGURE 10)
7
8
6
9
1k
2.4k
2.5
k
+15V
SWEEP IN
10
12
6
3
2
4
7
+
CA3140
-
7
2
8
5
6
1
4
3
9
5.1k
0.1
F
-15V
D
1
D
4
D
2
D
3
D
6
D
5
CA3019
DIODE ARRAY
EXTERNAL
OUTPUT
+15V
+15V
-15V
100
k
SUBSTRATE
OF CA3019
TO
WIDEBAND
OUTPUT
AMPLIFIER
7.5k
5.6k
-15V
R3 10k
10k
0.1
F
1M
9.1k
R
1
10k
R
2
1k
430
4
7
+
CA3140
-
0.1
+15V
-
15V
2
3
6
F
0.1
F
COARSE
RATE
SAWTOOTH
SYMMETRY
0.47
F
0.047
F
4700pF
470pF
7
3
2
6
4
+
CA3140
-
5
1
3
2
4
1
5
51k
6.8k
91k
10k
100
390
3.9
25k
+15V
-15V
10k
10k
100k
30k
43k
LOG
VIO
50k
LOG
RATE
10k
GATE
PULSE
OUTPUT
-15V
EXTERNAL OUTPUT
TO FUNCTION GENERATOR "SWEEP IN"
SWEEP WIDTH
TO OUTPUT
AMPLIFIER
36k
51k
75k
50k
SAWTOOTH
"LOG"
TRIANGLE
+15V
+15V
4
7
+
CA3140
-
3
2
6
+15V
TRANSISTORS
FROM CA3086
ARRAY
ADJUST
TRIANGLE
SAWTOOTH
"LOG"
8.2k
100k
100k
FINE
RATE
SAWTOOTH
22M
1M
18M
750k
"LOG"
1N914
1N914
SAWTOOTH AND
RAMP LOW LEVEL
SET (-14.5V)
-15V
CA3140, CA3140A
12
This circuit can be adjusted most easily with a distortion
analyzer, but a good first approximation can be made by
comparing the output signal with that of a sine wave
generator. The initial slope is adjusted with the
potentiometer R
1
, followed by an adjustment of R
2
. The final
slope is established by adjusting R
3
, thereby adding
additional segments that are contributed by these diodes.
Because there is some interaction among these controls,
repetition of the adjustment procedure may be necessary.
Sweeping Generator
Figure 13 shows a sweeping generator. Three CA3140s are
used in this circuit. One CA3140 is used as an integrator, a
second device is used as a hysteresis switch that
determines the starting and stopping points of the sweep. A
third CA3140 is used as a logarithmic shaping network for
the log function. Rates and slopes, as well as sawtooth,
triangle, and logarithmic sweeps are generated by this
circuit.
Wideband Output Amplifier
Figure 14 shows a high slew rate, wideband amplifier
suitable for use as a 50
transmission line driver. This
circuit, when used in conjunction with the function generator
and sine wave shaper circuits shown in Figures 10 and 12
provides 18V
P-P
output open circuited, or 9V
P-P
output
when terminated in 50
. The slew rate required of this
amplifier is 28V/
s (18V
P-P
x
x 0.5MHz).
Power Supplies
High input impedance, common mode capability down to the
negative supply and high output drive current capability are
key factors in the design of wide range output voltage
supplies that use a single input voltage to provide a
regulated output voltage that can be adjusted from
essentially 0V to 24V.
Unlike many regulator systems using comparators having a
bipolar transistor input stage, a high impedance reference
voltage divider from a single supply can be used in
connection with the CA3140 (see Figure 15).
Essentially, the regulators, shown in Figures 16 and 17, are
connected as non inverting power operational amplifiers with a
gain of 3.2. An 8V reference input yields a maximum output
voltage slightly greater than 25V. As a voltage follower, when
the reference input goes to 0V the output will be 0V. Because
the offset voltage is also multiplied by the 3.2 gain factor, a
potentiometer is needed to null the offset voltage.
Series pass transistors with high I
CBO
levels will also
prevent the output voltage from reaching zero because there
is a finite voltage drop (V
CESAT
) across the output of the
CA3140 (see Figure 2). This saturation voltage level may
indeed set the lowest voltage obtainable.
The high impedance presented by Terminal 8 is
advantageous in effecting current limiting. Thus, only a small
signal transistor is required for the current-limit sensing
amplifier. Resistive decoupling is provided for this transistor
to minimize damage to it or the CA3140 in the event of
unusual input or output transients on the supply rail.
Figures 16 and 17, show circuits in which a D2201 high speed
diode is used for the current sensor. This diode was chosen
for its slightly higher forward voltage drop characteristic, thus
giving greater sensitivity. It must be emphasized that heat
sinking of this diode is essential to minimize variation of the
current trip point due to internal heating of the diode. That is,
1A at 1V forward drop represents one watt which can result in
significant regenerative changes in the current trip point as the
diode temperature rises. Placing the small signal reference
amplifier in the proximity of the current sensing diode also
helps minimize the variability in the trip level due to the
negative temperature coefficient of the diode. In spite of those
limitations, the current limiting point can easily be adjusted
over the range from 10mA to 1A with a single adjustment
potentiometer. If the temperature stability of the current
limiting system is a serious consideration, the more usual
current sampling resistor type of circuitry should be employed.
A power Darlington transistor (in a metal can with heatsink),
is used as the series pass element for the conventional
current limiting system, Figure 16, because high power
Darlington dissipation will be encountered at low output
voltage and high currents.
2
6
8
1
4
7
+
CA3140
-
50
F
25V
2.2
k
2N3053
1N914
2.2
k
1N914
2.7
2.7
2N4037
+
-
+
-
50
F
25V
3
SIGNAL
LEVEL
ADJUSTMENT
2.5k
200
2.4pF
2pF
-15V
+15V
OUTPUT
DC LEVEL
ADJUSTMENT
-15V
+15V
3k
200
1.8k
51
2W
OUT
NOMINAL BANDWIDTH = 10MHz
t
r
= 35ns
FIGURE 14. WIDEBAND OUTPUT AMPLIFIER
6
3
2
4
7
+
CA3140
-
VOLTAGE
REFERENCE
VOLTAGE
ADJUSTMENT
REGULATED
OUTPUT
INPUT
FIGURE 15. BASIC SINGLE SUPPLY VOLTAGE REGULATOR
SHOWING VOLTAGE FOLLOWER
CA3140, CA3140A
13
A small heat sink VERSAWATT transistor is used as the
series pass element in the fold back current system, Figure
17, since dissipation levels will only approach 10W. In this
system, the D2201 diode is used for current sampling.
Foldback is provided by the 3k
and 100k
divider network
connected to the base of the current sensing transistor.
Both regulators provide better than 0.02% load regulation.
Because there is constant loop gain at all voltage settings, the
regulation also remains constant. Line regulation is 0.1% per
volt. Hum and noise voltage is less than 200
V as read with a
meter having a 10MHz bandwidth.
Figure 18A shows the turn ON and turn OFF characteristics
of both regulators. The slow turn on rise is due to the slow
rate of rise of the reference voltage. Figure 18B shows the
transient response of the regulator with the switching of a
20
load at 20V output.
FIGURE 16. REGULATED POWER SUPPLY
FIGURE 17. REGULATED POWER SUPPLY WITH
"FOLDBACK" CURRENT LIMITING
5V/Div., 1s/Div.
FIGURE 18A. SUPPLY TURN-ON AND TURNOFF
CHARACTERISTICS
Top Trace: Output Voltage;
200mV/Div., 5
s/Div.
Bottom Trace: Collector of load switching transistor, load = 1A;
5V/Div., 5
s/Div.
FIGURE 18B. TRANSIENT RESPONSE
FIGURE 18. WAVEFORMS OF DYNAMIC CHARACTERISTICS OF POWER SUPPLY CURRENTS SHOWN IN FIGURES 16 AND 17
1
3
75
3k
100
2
1k
1k
D2201
CURRENT
LIMITING
ADJUST
2N6385
POWER DARLINGTON
2
1k
1
3
8
2N2102
1k
+30V
INPUT
4
CA3140
7
1
6
5
100k
2
3
180k
56pF
1k
82k
250
F
+
-
0.01
F
100k
14
10
6
9
8
50k
13
5
F
+
-
12
CA3086
2.2k
3
1
5
4
62k
VOLTAGE
ADJUST
10
F
+
-
2.7k
1k
11
7
2
HUM AND NOISE OUTPUT <200
V
RMS
(MEASUREMENT BANDWIDTH
~
10MHz)
LINE REGULATION 0.1%/V
LOAD REGULATION
(NO LOAD TO FULL LOAD)
<0.02%
OUTPUT
0.1
24V
AT 1A
1
2
1k
200
D2201
"FOLDBACK" CURRENT
LIMITER
2N5294
3k
8
2N2102
1k
+30V
INPUT
4
CA3140
7
1
6
5
100k
2
3
180k
56pF
1k
82k
250
F
+
-
0.01
F
100k
14
10
6
9
8
50k
13
5
F
+
-
12
CA3086
2.2k
3
1
5
4
62k
VOLTAGE
ADJUST
10
F
+
-
2.7k
1k
11
7
2
HUM AND NOISE OUTPUT <200
V
RMS
(MEASUREMENT BANDWIDTH
~
10MHz)
LINE REGULATION 0.1%/V
LOAD REGULATION
(NO LOAD TO FULL LOAD)
<0.02%
OUTPUT
0V TO 25V
25V AT 1A
3
100k
"FOLDS BACK"
TO 40mA
100k
CA3140, CA3140A
14
Tone Control Circuits
High slew rate, wide bandwidth, high output voltage
capability and high input impedance are all characteristics
required of tone control amplifiers. Two tone control circuits
that exploit these characteristics of the CA3140 are shown in
Figures 19 and 20.
The first circuit, shown in Figure 20, is the Baxandall tone
control circuit which provides unity gain at midband and
uses standard linear potentiometers. The high input
impedance of the CA3140 makes possible the use of low-
cost, low-value, small size capacitors, as well as reduced
load of the driving stage.
Bass treble boost and cut are
15dB at 100Hz and 10kHz,
respectively. Full peak-to-peak output is available up to at
least 20kHz due to the high slew rate of the CA3140. The
amplifier gain is 3dB down from its "flat" position at 70kHz.
Figure 19 shows another tone control circuit with similar
boost and cut specifications. The wideband gain of this
circuit is equal to the ultimate boost or cut plus one, which in
this case is a gain of eleven. For 20dB boost and cut, the
input loading of this circuit is essentially equal to the value of
the resistance from Terminal No. 3 to ground. A detailed
analysis of this circuit is given in "An IC Operational
Transconductance Amplifier (OTA) With Power Capability"
by L. Kaplan and H. Wittlinger, IEEE Transactions on
Broadcast and Television Receivers, Vol. BTR-18, No. 3,
August, 1972.
FIGURE 19. TONE CONTROL CIRCUIT USING CA3130 SERIES (20dB MIDBAND GAIN)
FIGURE 20. BAXANDALL TONE CONTROL CIRCUIT USING CA3140 SERIES
4
7
+
CA3140
-
+30V
3
2
0.1
F
6
0.005
F
0.1
F
2.2M
2.2M
5.1
M
0.012
F
0.001
F
0.022
F
2
F
18k
0.0022
F
200k
(LINEAR)
100
pF
100pF
BOOST
TREBLE
CUT
BOOST
BASS
CUT
10k
1M
CCW (LOG)
100k
TONE CONTROL NETWORK
FOR SINGLE SUPPLY
-
+
+15V
3
0.1
F
0.005
F
5.1M
0.1
F
-15V
2
6
7
4
+
CA3140
-
TONE CONTROL NETWORK
FOR DUAL SUPPLIES
NOTES:
5. 20dB Flat Position Gain.
6.
15dB Bass and Treble Boost and Cut
at 100Hz and 10kHz, respectively.
7. 25V
P-P
output at 20kHz.
8. -3dB at 24kHz from 1kHz reference.
4
7
+
CA3140
-
+32V
3
0.1
2.2M
2.2
M
FOR SINGLE SUPPLY
F
6
2
0.1
F
20pF
750
pF
750
pF
2.2M
0.047
F
BOOST TREBLE
CUT
51k
5M
(LINEAR)
51k
TONE CONTROL NETWORK
BOOST
BASS
CUT
240k
5M
(LINEAR)
240k
+15V
3
0.1
F
0.047
F
0.1
F
-15V
2
6
7
4
+
CA3140
-
FOR DUAL SUPPLIES
:
9.
15dB Bass and Treble Boost and Cut at 100Hz and 10kHz, Respectively.
10. 25V
P-P
Output at 20kHz.
11. -3dB at 70kHz from 1kHz Reference.
12. 0dB Flat Position Gain.
TONE CONTROL
NETWORK
CA3140, CA3140A
15
Wien Bridge Oscillator
Another application of the CA3140 that makes excellent use
of its high input impedance, high slew rate, and high voltage
qualities is the Wien Bridge sine wave oscillator. A basic Wien
Bridge oscillator is shown in Figure 21. When R
1
= R
2
= R
and C
1
= C
2
= C, the frequency equation reduces to the
familiar f = 1/(2
RC) and the gain required for oscillation,
A
OSC
is equal to 3. Note that if C
2
is increased by a factor of
four and R
2
is reduced by a factor of four, the gain required
for oscillation becomes 1.5, thus permitting a potentially
higher operating frequency closer to the gain bandwidth
product of the CA3140.
Oscillator stabilization takes on many forms. It must be
precisely set, otherwise the amplitude will either diminish or
reach some form of limiting with high levels of distortion. The
element, R
S
, is commonly replaced with some variable
resistance element. Thus, through some control means, the
value of R
S
is adjusted to maintain constant oscillator output.
A FET channel resistance, a thermistor, a lamp bulb, or
other device whose resistance increases as the output
amplitude is increased are a few of the elements often
utilized.
Figure 22 shows another means of stabilizing the oscillator
with a zener diode shunting the feedback resistor (R
F
of
Figure 21). As the output signal amplitude increases, the
zener diode impedance decreases resulting in more
feedback with consequent reduction in gain; thus stabilizing
the amplitude of the output signal. Furthermore, this
combination of a monolithic zener diode and bridge rectifier
circuit tends to provide a zero temperature coefficient for this
regulating system. Because this bridge rectifier system has
no time constant, i.e., thermal time constant for the lamp
bulb, and RC time constant for filters often used in detector
networks, there is no lower frequency limit. For example,
with 1
F polycarbonate capacitors and 22M
for the
frequency determining network, the operating frequency is
0.007Hz.
As the frequency is increased, the output amplitude must be
reduced to prevent the output signal from becoming slew-
rate limited. An output frequency of 180kHz will reach a slew
rate of approximately 9V/
s when its amplitude is 16V
P-P
.
Simple Sample-and-Hold System
Figure 23 shows a very simple sample-and-hold system
using the CA3140 as the readout amplifier for the storage
capacitor. The CA3080A serves as both input buffer
amplifier and low feed-through transmission switch (see
Note 13). System offset nulling is accomplished with the
CA3140 via its offset nulling terminals. A typical simulated
load of 2k
and 30pF is shown in the schematic.
In this circuit, the storage compensation capacitance (C
1
) is
only 200pF. Larger value capacitors provide longer "hold"
periods but with slower slew rates. The slew rate is:
NOTE:
13. AN6668 "Applications of the CA3080 and CA 3080A High
Performance Operational Transconductance Amplifiers".
NOTES:
f
1
2
R
1
C
1
R
2
C
2
-------------------------------------------
=
A
OSC
1
C
1
C
2
-------
R
2
R
1
-------
+
+
=
A
CL
1
R
F
R
S
--------
+
=
C
1
R
2
R
1
C
2
OUTPUT
R
F
R
S
+
-
FIGURE 21. BASIC WIEN BRIDGE OSCILLATOR CIRCUIT
USING AN OPERATIONAL AMPLIFIER
8
5
4
3
1
9
6
CA3109
DIODE
ARRAY
+15V
0.1
F
0.1
F
-15V
2
6
7
4
+
CA3140
-
SUBSTRATE
OF CA3019
0.1
F
7
7.5k
3.6k
500
OUTPUT
19V
P-P
TO 22V
P-P
THD <0.3%
3
R
2
C
2
1000pF
1000
pF
C
1
R
1
R
1
= R
2
= R
50Hz, R = 3.3M
100Hz, R = 1.6M
1kHz, R = 160M
10kHz, R = 16M
30kHz, R = 5.1M
2
FIGURE 22. WIEN BRIDGE OSCILLATOR CIRCUIT USING
CA3140
+15V
3.5k
30pF
2
6
1
+
CA3140
-
SIMULATED LOAD
NOT REQUIRED
100k
INPUT
0.1
0.1
F
F
7
0.1
F
-15V
2k
3
400
200pF
6
4
5
7
4
+
CA3080A
-
0.1
F
+15V
-15V
200pF
2k
2
3
5
2k
STROBE
SAMPLE
HOLD
-15
0
30k
1N914
1N914
2k
C
1
FIGURE 23. SAMPLE AND HOLD CIRCUIT
dv
dt
------
I
C
----
0.5mA 200pF
/
2.5V
s
/
=
=
=
CA3140, CA3140A
16
Pulse "droop" during the hold interval is 170pA/200pF which is
0.85
V/
s; (i.e., 170pA/200pF). In this case, 170pA represents
the typical leakage current of the CA3080A when strobed off. If
C
1
were increased to 2000pF, the "hold-droop" rate will
decrease to 0.085
V/
s, but the slew rate would decrease to
0.25V/
s. The parallel diode network connected between
Terminal 3 of the CA3080A and Terminal 6 of the CA3140
prevents large input signal feedthrough across the input
terminals of the CA3080A to the 200pF storage capacitor when
the CA3080A is strobed off. Figure 24 shows dynamic
characteristic waveforms of this sample-and-hold system.
Current Amplifier
The low input terminal current needed to drive the CA3140
makes it ideal for use in current amplifier applications such
as the one shown in Figure 25 (see Note 14). In this circuit,
low current is supplied at the input potential as the power
supply to load resistor R
L
. This load current is increased by
the multiplication factor R
2
/R
1
, when the load current is
monitored by the power supply meter M. Thus, if the load
current is 100nA, with values shown, the load current
presented to the supply will be 100
A; a much easier current
to measure in many systems.
Note that the input and output voltages are transferred at the
same potential and only the output current is multiplied by
the scale factor.
The dotted components show a method of decoupling the
circuit from the effects of high output load capacitance and
the potential oscillation in this situation. Essentially, the
necessary high frequency feedback is provided by the
capacitor with the dotted series resistor providing load
decoupling.
Full Wave Rectifier
Figure 26 shows a single supply, absolute value, ideal full-
wave rectifier with associated waveforms. During positive
excursions, the input signal is fed through the feedback
network directly to the output. Simultaneously, the positive
excursion of the input signal also drives the output terminal
(No. 6) of the inverting amplifier in a negative going
excursion such that the 1N914 diode effectively disconnects
the amplifier from the signal path. During a negative going
excursion of the input signal, the CA3140 functions as a
normal inverting amplifier with a gain equal to -R
2
/R
1
. When
the equality of the two equations shown in Figure 26 is
satisfied, the full wave output is symmetrical.
NOTE:
14. "Operational Amplifiers Design and Applications", J. G. Graeme,
McGraw-Hill Book Company, page 308, "Negative Immittance
Converter Circuits".
Top Trace: Output; 50mV/Div., 200ns/Div.
Bottom Trace: Input; 50mV/Div., 200ns/Div.
Top Trace: Output Signal; 5V/Div, 2
s/Div.
Center Trace: Difference of Input and Output Signals through
Tektronix Amplifier 7A13; 5mV/Div., 2
s/Div.
Bottom Trace: Input Signal; 5V/Div., 2
s/Div.
LARGE SIGNAL RESPONSE AND SETTLING TIME
SAMPLING RESPONSE
Top Trace: Output; 100mV/Div., 500ns/Div.
Bottom Trace: Input; 20V/Div., 500ns/Div.
FIGURE 24. SAMPLE AND HOLD SYSTEM DYNAMIC
CHARACTERISTICS WAVEFORMS
+15V
2
1
100k
0.1
F
-15V
4
5
7
+
CA3140
-
0.1
F
4.3k
10k
6
3
R
1
POWER
SUPPLY
10M
R
2
I
L
R
2
R
1
M
R
L
I
L
x
FIGURE 25. BASIC CURRENT AMPLIFIER FOR LOW CURRENT
MEASUREMENT SYSTEMS
CA3140, CA3140A
17
+15V
3
0.1
F
8
5k
7
1
5
6
2
R
2
R
1
10k
R
3
1N914
10k
100k
OFFSET
ADJUST
4
PEAK
ADJUST
10k
+
CA3140
-
20V
P-P
Input BW (-3dB) = 290kHz, DC Output (Avg) = 3.2V
GAIN
R
2
R
1
-------
X
R
3
R
1
R
2
R
3
+
-----------------------------
=
=
=
R
3
X X
2
+
1 X
-----------------
R
1
=
FOR X
0.5
5k
10k
---------------
R
2
R
1
-------
=
=
R
3
10k
0.75
0.5
-----------
15k
=
=
OUTPUT
0
INPUT
0
FIGURE 26. SINGLE SUPPLY, ABSOLUTE VALUE, IDEAL
FULL WAVE RECTIFIER WITH ASSOCIATED
WAVEFORMS
+15V
-15V
2
7
4
+
CA3140
-
3
0.01
F
0.01
F
6
1M
NOISE VOLTAGE
OUTPUT
30.1k
1k
R
S
BW (-3dB) = 140kHz
TOTAL NOISE VOLTAGE
(REFERRED TO INPUT) = 48
V (TYP)
FIGURE 27. TEST CIRCUIT AMPLIFIER (30dB GAIN) USED FOR
WIDEBAND NOISE MEASUREMENT
Top Trace: Output; 50mV/Div., 200ns/Div.
Bottom Trace: Input; 50mV/Div., 200ns/Div.
FIGURE 28B. SMALL SIGNAL RESPONSE
(Measurement made with Tektronix 7A13 differential amplifier.)
Top Trace: Output Signal; 5V/Div., 5
s/Div.
Center Trace: Difference Signal; 5mV/Div., 5
s/Div.
Bottom Trace: Input Signal; 5V/Div., 5
s/Div.
FIGURE 28C. INPUT-OUTPUT DIFFERENCE SIGNAL SHOWING
SETTLING TIME
FIGURE 28. SPLIT SUPPLY VOLTAGE FOLLOWER TEST
CIRCUIT AND ASSOCIATED WAVEFORMS
+15V
-15V
2
7
4
+
CA3140
-
3
0.1
F
0.1
F
6
0.05
F
2k
10k
100pF
SIMULATED
LOAD
2k
BW (-3dB) = 4.5MHz
SR = 9V/
s
FIGURE 28A. TEST CIRCUIT
INPUT
CA3140, CA3140A
18
Typical Performance Curves
FIGURE 29. OPEN-LOOP VOLTAGE GAIN vs SUPPLY
VOLTAGE AND TEMPERATURE
FIGURE 30. GAIN BANDWIDTH PRODUCT vs SUPPLY
VOLTAGE AND TEMPERATURE
FIGURE 31. SLEW RATE vs SUPPLY VOLTAGE AND
TEMPERATURE
FIGURE 32. QUIESCENT SUPPLY CURRENT vs SUPPLY
VOLTAGE AND TEMPERATURE
FIGURE 33. MAXIMUM OUTPUT VOLTAGE SWING vs
FREQUENCY
FIGURE 34. COMMON MODE REJECTION RATIO vs
FREQUENCY
125
100
75
50
25
O
PEN-
L
O
O
P VO
L
T
AG
E G
A
I
N
(
d
B)
0
5
10
15
20
SUPPLY VOLTAGE (V)
125
o
C
25
o
C
T
A
= -55
o
C
R
L
= 2k
25
0
G
A
IN BANDWI
D
T
H
PRO
DUCT

(
M
H
z
)
125
o
C
25
o
C
T
A
= -55
o
C
R
L
= 2k
20
10
0
5
10
15
20
SUPPLY VOLTAGE (V)
25
C
L
= 100pF
1
125
o
C
25
o
C
T
A
= -55
o
C
R
L
= 2k
5
10
15
20
SUPPLY VOLTAGE (V)
25
C
L
= 100pF
20
15
10
5
0
SLEW
RAT
E
(
V
/
s)
0
7
6
5
4
3
0
5
10
15
20
SUPPLY VOLTAGE (V)
125
o
C
T
A
= -55
o
C
R
L
=
25
0
2
1
25
o
C
Q
U
I
E
S
C
ENT SUPPL
Y CUR
RE
NT (
m
A)
25
20
15
10
5
0
OUT
P
UT
S
W
ING
(V
P-
P
)
10K
100K
FREQUENCY (Hz)
1M
4M
SUPPLY VOLTAGE: V
S
=
15V
T
A
= 25
o
C
120
100
80
60
40
20
0
COM
M
ON-
M
O
DE REJ
E
CT
ION RAT
IO (
d
B)
10
1
10
2
10
3
10
4
10
5
10
6
10
7
FREQUENCY (Hz)
SUPPLY VOLTAGE: V
S
=
15V
T
A
= 25
o
C
CA3140, CA3140A
19
FIGURE 35. EQUIVALENT INPUT NOISE VOLTAGE vs
FREQUENCY
FIGURE 36. POWER SUPPLY REJECTION RATIO vs
FREQUENCY
Typical Performance Curves
(Continued)
SUPPLY VOLTAGE: V
S
=
15V
T
A
= 25
o
C
FREQUENCY (Hz)
1
10
1
10
2
10
3
10
4
10
5
E
Q
U
I
V
A
L
E
NT
INP
U
T
NOIS
E
V
O
L
T
A
GE
(n
V
/
Hz)
100
10
1
1000
10
2
10
3
10
4
10
5
10
6
10
7
FREQUENCY (Hz)
POWER
SUPP
L
Y
REJ
E
CT
ION RAT
IO (
d
B) 100
80
60
40
20
0
+PSRR
-PSRR
SUPPLY VOLTAGE: V
S
=
15V
T
A
= 25
o
C
POWER SUPPLY REJECTION RATIO
(PSRR) =
V
IO
/
V
S
10
1
CA3140, CA3140A
20
Metallization Mask Layout
Dimensions in parenthesis are in millimeters and are derived
from the basic inch dimensions as indicated. Grid graduations
are in mils (10
-3
inch).
The photographs and dimensions represent a chip when it is
part of the wafer. When the wafer is cut into chips, the cleavage
angles are 57
o
instead of 90
with respect to the face of the
chip. Therefore, the isolated chip is actually 7 mils (0.17mm)
larger in both dimensions.
62-70
(1.575-1.778)
4-10
(0.102-0.254)
60
50
40
30
20
10
0
58-66
(1.473-1.676)
50
40
30
20
10
61
0
60 65
CA3140, CA3140A
21
CA3140, CA3140A
Dual-In-Line Plastic Packages (PDIP)
CL
E
e
A
C
e
B
e
C
-B-
E1
INDEX
1 2 3
N/2
N
AREA
SEATING
BASE
PLANE
PLANE
-C-
D1
B1
B
e
D
D1
A
A2
L
A
1
-A-
0.010 (0.25)
C A
M
B S
NOTES:
1. Controlling Dimensions: INCH. In case of conflict between
English and Metric dimensions, the inch dimensions control.
2. Dimensioning and tolerancing per ANSI Y14.5M-1982.
3. Symbols are defined in the "MO Series Symbol List" in Section
2.2 of Publication No. 95.
4. Dimensions A, A1 and L are measured with the package seated
in JEDEC seating plane gauge GS-3.
5. D, D1, and E1 dimensions do not include mold flash or protru-
sions. Mold flash or protrusions shall not exceed 0.010 inch
(0.25mm).
6. E and
are measured with the leads constrained to be per-
pendicular to datum
.
7. e
B
and e
C
are measured at the lead tips with the leads uncon-
strained. e
C
must be zero or greater.
8. B1 maximum dimensions do not include dambar protrusions.
Dambar protrusions shall not exceed 0.010 inch (0.25mm).
9. N is the maximum number of terminal positions.
10. Corner leads (1, N, N/2 and N/2 + 1) for E8.3, E16.3, E18.3,
E28.3, E42.6 will have a B1 dimension of 0.030 - 0.045 inch
(0.76 - 1.14mm).
e
A
-C-
E8.3
(JEDEC MS-001-BA ISSUE D)
8 LEAD DUAL-IN-LINE PLASTIC PACKAGE
SYMBOL
INCHES
MILLIMETERS
NOTES
MIN
MAX
MIN
MAX
A
-
0.210
-
5.33
4
A1
0.015
-
0.39
-
4
A2
0.115
0.195
2.93
4.95
-
B
0.014
0.022
0.356
0.558
-
B1
0.045
0.070
1.15
1.77
8, 10
C
0.008
0.014
0.204
0.355
-
D
0.355
0.400
9.01
10.16
5
D1
0.005
-
0.13
-
5
E
0.300
0.325
7.62
8.25
6
E1
0.240
0.280
6.10
7.11
5
e
0.100 BSC
2.54 BSC
-
e
A
0.300 BSC
7.62 BSC
6
e
B
-
0.430
-
10.92
7
L
0.115
0.150
2.93
3.81
4
N
8
8
9
Rev. 0 12/93
22
All Intersil U.S. products are manufactured, assembled and tested utilizing ISO9000 quality systems.
Intersil Corporation's quality certifications can be viewed at www.intersil.com/design/quality
Intersil products are sold by description only. Intersil Corporation reserves the right to make changes in circuit design, software and/or specifications at any time without
notice. Accordingly, the reader is cautioned to verify that data sheets are current before placing orders. Information furnished by Intersil is believed to be accurate and
reliable. However, no responsibility is assumed by Intersil or its subsidiaries for its use; nor for any infringements of patents or other rights of third parties which may result
from its use. No license is granted by implication or otherwise under any patent or patent rights of Intersil or its subsidiaries.
For information regarding Intersil Corporation and its products, see www.intersil.com
CA3140, CA3140A
Small Outline Plastic Packages (SOIC)
INDEX
AREA
E
D
N
1
2
3
-B-
0.25(0.010)
C A
M
B S
e
-A-
L
B
M
-C-
A1
A
SEATING PLANE
0.10(0.004)
h x 45
o
C
H
0.25(0.010)
B
M
M
NOTES:
1. Symbols are defined in the "MO Series Symbol List" in Section 2.2 of
Publication Number 95.
2. Dimensioning and tolerancing per ANSI Y14.5M-1982.
3. Dimension "D" does not include mold flash, protrusions or gate burrs.
Mold flash, protrusion and gate burrs shall not exceed 0.15mm (0.006
inch) per side.
4. Dimension "E" does not include interlead flash or protrusions. Inter-
lead flash and protrusions shall not exceed 0.25mm (0.010 inch) per
side.
5. The chamfer on the body is optional. If it is not present, a visual index
feature must be located within the crosshatched area.
6. "L" is the length of terminal for soldering to a substrate.
7. "N" is the number of terminal positions.
8. Terminal numbers are shown for reference only.
9. The lead width "B", as measured 0.36mm (0.014 inch) or greater
above the seating plane, shall not exceed a maximum value of
0.61mm (0.024 inch).
10. Controlling dimension: MILLIMETER. Converted inch dimensions
are not necessarily exact.
M8.15
(JEDEC MS-012-AA ISSUE C)
8 LEAD NARROW BODY SMALL OUTLINE PLASTIC
PACKAGE
SYMBOL
INCHES
MILLIMETERS
NOTES
MIN
MAX
MIN
MAX
A
0.0532
0.0688
1.35
1.75
-
A1
0.0040
0.0098
0.10
0.25
-
B
0.013
0.020
0.33
0.51
9
C
0.0075
0.0098
0.19
0.25
-
D
0.1890
0.1968
4.80
5.00
3
E
0.1497
0.1574
3.80
4.00
4
e
0.050 BSC
1.27 BSC
-
H
0.2284
0.2440
5.80
6.20
-
h
0.0099
0.0196
0.25
0.50
5
L
0.016
0.050
0.40
1.27
6
N
8
8
7
0
o
8
o
0
o
8
o
-
Rev. 0 12/93