CA3140, CA3140A Datasheet 3140 Ca3140 A

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DATASHEET
CA3140, CA3140A

FN957
Rev.10.00
Jul 11, 2005

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 (ZIN) -1.5T (Typ)
- Very Low Input Current (Il) -10pA (Typ) at 15V
- Wide Common Mode Input Voltage Range (VlCR) - 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
• Pb-Free Plus Anneal Available (RoHS Compliant)

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

FN957 Rev.10.00
Jul 11, 2005

OFFSET
NULL

1

INV. INPUT

2

NON-INV.
INPUT

3

V-

4

+

8

STROBE

7

V+

6

OUTPUT

5

OFFSET
NULL

Page 1 of 24

CA3140, CA3140A

Ordering Information
PART NUMBER
(BRAND)

TEMP.
RANGE (°C)

PACKAGE

PKG.
DWG. #

CA3140AE

-55 to 125

8 Ld PDIP

E8.3

CA3140AEZ*
(See Note)

-55 to 125

8 Ld PDIP
(Pb-free)

E8.3

CA3140AM
(3140A)

-55 to 125

8 Ld SOIC

M8.15

CA3140AM96
(3140A)

-55 to 125

8 Ld SOIC Tape and Reel

CA3140AMZ
(3140A) (See Note)

-55 to 125

8 Ld SOIC
(Pb-free)

CA3140AMZ96
(3140A) (See Note)

-55 to 125

8 Ld SOIC Tape and Reel
(Pb-free)

CA3140E

-55 to 125

8 Ld PDIP

E8.3

CA3140EZ*
(See Note)

-55 to 125

8 Ld PDIP
(Pb-free)

E8.3

CA3140M
(3140)

-55 to 125

8 Ld SOIC

M8.15

CA3140M96
(3140)

-55 to 125

8 Ld SOIC Tape and Reel

CA3140MZ
(3140) (See Note)

-55 to 125

8 Ld SOIC
(Pb-free)

CA3140MZ96
(3140) (See Note)

-55 to 125

8 Ld SOIC Tape and Reel
(Pb-free)

M8.15

M8.15

*Pb-free PDIPs can be used for through hole wave solder
processing only. They are not intended for use in Reflow solder
processing applications.
NOTE: Intersil Pb-free products employ special Pb-free material
sets; molding compounds/die attach materials and 100% matte tin
plate termination finish, which are RoHS compliant and compatible
with both SnPb and Pb-free soldering operations. Intersil Pb-free
products are MSL classified at Pb-free peak reflow temperatures
that meet or exceed the Pb-free requirements of IPC/JEDEC J STD020.

FN957 Rev.10.00
Jul 11, 2005

Page 2 of 24

CA3140, CA3140A
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

Thermal Resistance (Typical, Note 1)
JA (oC/W) JC (oC/W)
PDIP Package* . . . . . . . . . . . . . . . . . .
115
N/A
SOIC Package . . . . . . . . . . . . . . . . . . .
165
N/A
Maximum Junction Temperature (Plastic Package) . . . . . . . 150oC
Maximum Storage Temperature Range . . . . . . . . . . -65oC to 150oC
Maximum Lead Temperature (Soldering 10s) . . . . . . . . . . . . 300oC
(SOIC - Lead Tips Only)

Operating Conditions
Temperature Range . . . . . . . . . . . . . . . . . . . . . . . . . -55oC to 125oC

*Pb-free PDIPs can be used for through hole wave solder processing only. They are not intended for use in Reflow solder processing
applications.
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

VSUPPLY = 15V, TA = 25oC
TYPICAL VALUES

PARAMETER

SYMBOL

Input Offset Voltage Adjustment Resistor

TEST CONDITIONS
Typical Value of Resistor
Between Terminals 4 and 5 or 4 and 1 to
Adjust Max VIO

CA3140

CA3140A

UNITS

4.7

18

k

Input Resistance

RI

1.5

1.5

T

Input Capacitance

CI

4

4

pF

Output Resistance

RO

60

60



Equivalent Wideband Input Noise Voltage
(See Figure 27)

eN

BW = 140kHz, RS = 1M

48

48

V

Equivalent Input Noise Voltage (See Figure 35)

eN

RS = 100

f = 1kHz

40

40

nV/Hz

f = 10kHz

12

12

nV/Hz

IOM+

Source

40

40

mA

IOM-

Sink

18

18

mA

Short Circuit Current to Opposite Supply

Gain-Bandwidth Product, (See Figures 6, 30)

fT

4.5

4.5

MHz

Slew Rate, (See Figure 31)

SR

9

9

V/s

220

220

A

Rise Time

0.08

0.08

s

Overshoot

10

10

%

To 1mV

4.5

4.5

s

To 10mV

1.4

1.4

s

Sink Current From Terminal 8 To Terminal 4 to
Swing Output Low
Transient Response (See Figure 28)

tr
OS

Settling Time at 10VP-P, (See Figure 5)

Electrical Specifications

tS

RL = 2k
CL = 100pF
RL = 2k
CL = 100pF
Voltage Follower

For Equipment Design, at VSUPPLY = 15V, TA = 25oC, Unless Otherwise Specified
CA3140

PARAMETER

CA3140A

SYMBOL

MIN

TYP

MAX

MIN

TYP

MAX

UNITS

Input Offset Voltage

|VIO|

-

5

15

-

2

5

mV

Input Offset Current

|IIO|

-

0.5

30

-

0.5

20

pA

II

-

10

50

-

10

40

pA

Input Current

FN957 Rev.10.00
Jul 11, 2005

Page 3 of 24

CA3140, CA3140A
Electrical Specifications

For Equipment Design, at VSUPPLY = 15V, TA = 25oC, Unless Otherwise Specified (Continued)
CA3140

PARAMETER
Large Signal Voltage Gain (Note 3)
(See Figures 6, 29)
Common Mode Rejection Ratio
(See Figure 34)

CA3140A

SYMBOL

MIN

TYP

MAX

MIN

TYP

MAX

UNITS

AOL

20

100

-

20

100

-

kV/V

86

100

-

86

100

-

dB

-

32

320

-

32

320

V/V

70

90

-

70

90

-

dB

CMRR

Common Mode Input Voltage Range (See Figure 8)

VICR

-15

-15.5 to +12.5

11

-15

-15.5 to +12.5

12

V

Power-Supply Rejection Ratio,
VIO/VS (See Figure 36)

PSRR

-

100

150

-

100

150

V/V

76

80

-

76

80

-

dB

Max Output Voltage (Note 4)
(See Figures 2, 8)

VOM+

+12

13

-

+12

13

-

V

VOM-

-14

-14.4

-

-14

-14.4

-

V

Supply Current (See Figure 32)

I+

-

4

6

-

4

6

mA

Device Dissipation

PD

-

120

180

-

120

180

mW

VIO/T

-

8

-

-

6

-

V/oC

Input Offset Voltage Temperature Drift
NOTES:
3. At VO = 26VP-P , +12V, -14V and RL = 2k.
4. At RL = 2k.

Electrical Specifications

For Design Guidance At V+ = 5V, V- = 0V, TA = 25oC
TYPICAL VALUES
SYMBOL

CA3140

CA3140A

UNITS

Input Offset Voltage

PARAMETER

|VIO|

5

2

mV

Input Offset Current

|IIO|

0.1

0.1

pA

Input Current

II

2

2

pA

Input Resistance

RI

1

1

T

AOL

100

100

kV/V

100

100

dB

CMRR

32

32

V/V

90

90

dB

VICR

-0.5

-0.5

V

2.6

2.6

V

PSRR
VIO/VS

100

100

V/V

80

80

dB

VOM+

3

3

V

VOM-

0.13

0.13

V

Source

IOM+

10

10

mA

Sink

I

Large Signal Voltage Gain (See Figures 6, 29)

Common Mode Rejection Ratio

Common Mode Input Voltage Range (See Figure 8)

Power Supply Rejection Ratio

Maximum Output Voltage (See Figures 2, 8)

Maximum Output Current:

OM-

1

1

mA

Slew Rate (See Figure 31)

SR

7

7

V/s

Gain-Bandwidth Product (See Figure 30)

fT

3.7

3.7

MHz

Supply Current (See Figure 32)

I+

1.6

1.6

mA

Device Dissipation

PD

8

8

mW

FN957 Rev.10.00
Jul 11, 2005

Page 4 of 24

CA3140, CA3140A
Electrical Specifications

For Design Guidance At V+ = 5V, V- = 0V, TA = 25oC (Continued)
TYPICAL VALUES

PARAMETER

SYMBOL

CA3140

CA3140A

UNITS

200

200

A

Sink Current from Terminal 8 to Terminal 4 to Swing Output Low

Block Diagram
2mA

4mA

7 V+

BIAS CIRCUIT
CURRENT SOURCES
AND REGULATOR
+

200A

3
INPUT

-

A 10

2

1.6mA

200A

2A

A
10,000

2mA

A 1

C1
12pF
5
1
OFFSET
NULL

FN957 Rev.10.00
Jul 11, 2005

6 OUTPUT

4 V8

STROBE

Page 5 of 24

CA3140, CA3140A

Schematic Diagram
BIAS CIRCUIT

INPUT STAGE

SECOND STAGE

OUTPUT STAGE

DYNAMIC CURRENT SINK
7 V+

D1

D7

Q1

Q3

Q2

D8

R10
1K

Q4

Q5

Q6

Q20

R9
50

Q19 R11
20

Q7

R12
12K

R14
20K

Q21

Q17

R1
8K

R13
5K

R8

Q8

1K Q
18
D2

D3

6 OUTPUT

D4
D5

INVERTING
INPUT

2

NON-INVERTING
INPUT

3

-

Q9

+

Q10
C1

R2
500

R3
500

Q11
R4
500

Q15

1

Q16
D6

R6
50

R5
500

OFFSET NULL

Q14

Q13

Q12

5

NOTE:

12pF

R7
30

8

4

STROBE

V-

All resistance values are in ohms.

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 (Q9, Q10) working into a mirror pair
of bipolar transistors (Q11, Q12) functioning as load resistors
together with resistors R2 through R5. The mirror pair transistors
also function as a differential-to-single-ended converter to provide

FN957 Rev.10.00
Jul 11, 2005

base current drive to the second stage bipolar transistor (Q13).
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 Q2, Q5 are the constant current source for the input
stage. The base biasing circuit for the constant current source is
described subsequently. The small diodes D3, D4, D5 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 Q13 and
its cascode connected load resistance provided by bipolar
transistors Q3, Q4. On-chip phase compensation, sufficient for
a majority of the applications is provided by C1. 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

Page 6 of 24

CA3140, CA3140A
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 (Q17, Q18) is established by transistors (Q14, Q15) whose
base currents are “mirrored” to current flowing through diode D2 in
the bias circuit section. When the CA3140 is operating such that
output Terminal 6 is sourcing current, transistor Q18 functions as
an emitter-follower to source current from the V+ bus (Terminal 7),
via D7, R9, and R11. Under these conditions, the collector
potential of Q13 is sufficiently high to permit the necessary flow of
base current to emitter follower Q17 which, in turn, drives Q18.

current in diode connected transistor Q2 establishes the currents
in transistors Q14 and Q15.

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.

When the CA3140 is operating such that output Terminal 6 is
sinking current to the V- bus, transistor Q16 is the current sinking
element. Transistor Q16 is mirror connected to D6, R7, with
current fed by way of Q21, R12, and Q20. Transistor Q20, in turn,
is biased by current flow through R13, zener D8, and R14. 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 Q13 is driven below
its quiescent level, thereby causing Q17, Q18 to decrease the
output voltage at Terminal 6. Thus, the gate terminal of PMOS
transistor Q21 is displaced toward the V- bus, thereby reducing
the channel resistance of Q21. As a consequence, there is an
incremental increase in current flow through Q20, R12, Q21, D6,
R7, and the base of Q16. As a result, Q16 sinks current from
Terminal 6 in direct response to the incremental change in output
voltage caused by Q18. This sink current flows regardless of load;
any excess current is internally supplied by the emitter-follower
Q18. Short circuit protection of the output circuit is provided by
Q19, which is driven into conduction by the high voltage drop
developed across R11 under output short circuit conditions. Under
these conditions, the collector of Q19 diverts current from Q4 so
as to reduce the base current drive from Q17, thereby limiting
current flow in Q18 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 R1. The
function of the bias circuit is to establish and maintain constant
current flow through D1, Q6, Q8 and D2. D1 is a diode connected
transistor mirror connected in parallel with the base emitter
junctions of Q1, Q2, and Q3. D1 may be considered as a current
sampling diode that senses the emitter current of Q6 and
automatically adjusts the base current of Q6 (via Q1) to maintain a
constant current through Q6, Q8, D2. The base currents in Q2, Q3
are also determined by constant current flow D1. Furthermore,

FN957 Rev.10.00
Jul 11, 2005

Page 7 of 24

CA3140, CA3140A
power transistors and thyristors directly without the need for
level shifting circuitry usually associated with the 741 series of
operational amplifiers.

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.
V+
5V TO 36V
2

6.2V
6

CA3140
3

Offset Voltage Nulling

LOGIC
SUPPLY
5V

7
8

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.

TYPICAL
TTL GATE

 5V

4

Figure 4 shows some typical configurations. Note that a series
resistor, RL, 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.

OUTPUT STAGE TRANSISTOR (Q15, Q16)
SATURATION VOLTAGE (mV)

FIGURE 1. ZENER CLAMPING DIODE CONNECTED TO
TERMINALS 8 AND 4 TO LIMIT CA3140 OUTPUT
SWING TO TTL LEVELS
1000

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.

SUPPLY VOLTAGE (V-) = 0V
TA = 25oC

SUPPLY VOLTAGE (V+) = +5V

100

+15V

Low Voltage Operation

+30V

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.

10

1
0.01

0.1
1.0
LOAD (SINKING) CURRENT (mA)

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.

10

FIGURE 2. VOLTAGE ACROSS OUTPUT TRANSISTORS (Q15
AND Q16) vs LOAD CURRENT

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
V+

V+
2

2

7
CA3140

3
1

5

2
6

CA3140

6
3

4
R

V+

7

1

3

R

1

10k

10k

6

CA3140

4

5

7

5

4

10k
R

V-

FIGURE 3A. BASIC

V-

FIGURE 3B. IMPROVED RESOLUTION

V-

FIGURE 3C. SIMPLER IMPROVED RESOLUTION

FIGURE 3. THREE OFFSET VOLTAGE NULLING METHODS

FN957 Rev.10.00
Jul 11, 2005

Page 8 of 24

CA3140, CA3140A

RS

V+
LOAD

30V
NO LOAD
120VAC

2

2

MT2

7
CA3140

6

6
RL

4

MT1

RL

LOAD

CA3140
3

3

+HV

7

4

FIGURE 4. METHODS OF UTILIZING THE VCE(SAT) SINKING CURRENT CAPABILITY OF THE CA3140 SERIES

FOLLOWER
+15V
7

0.1F

3

SIMULATED
LOAD

10k
CA3140
2

0.05F

10

1mV
10mV

INPUT VOLTAGE (V)

0.1F

-15V
2k

SUPPLY VOLTAGE: VS = 15V
TA = 25oC

6

2k

100pF

4

LOAD RESISTANCE (RL) = 2k
LOAD CAPACITANCE (CL) = 100pF

8

6

1mV

INVERTING
5k

10mV

+15V

4

7

2

2

FOLLOWER

0

INVERTING

-2

CA3140

200

-4
1mV

-8

10mV

-10
0.1

1mV

1.0
SETTLING TIME (s)

4

4.99k

10mV

6

0.1F

2k

5.11k

-15V
SETTLING POINT

10
D1

D2

1N914

FIGURE 5A. WAVEFORM

SIMULATED
LOAD
100pF

3

-6

0.1F

5k

1N914

FIGURE 5B. TEST CIRCUITS

FIGURE 5. SETTLING TIME vs INPUT VOLTAGE

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.

FN957 Rev.10.00
Jul 11, 2005

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 the CA3140 is

Page 9 of 24

CA3140, CA3140A

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.

100

-75

SUPPLY VOLTAGE: VS = 15V
TA = 25oC
OL

RL = 2k,
CL = 0pF

-90
-105
-120
-135

80

-150

OPEN LOOP PHASE
(DEGREES)

OPEN LOOP VOLTAGE GAIN (dB)

It is well known that MOSFET devices can exhibit slight
changes in characteristics (for example, small changes in input

60
RL = 2k,
CL = 100pF

40

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 125oC (for metal can); at
lower temperatures (metal can and plastic), for example, at
85oC, 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.

10K

INPUT CURRENT (pA)

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.

SUPPLY VOLTAGE: VS = 15V

1K

100

10

20
0
101

102

103

104
105
106
FREQUENCY (Hz)

107

1
-60

108

RL = 
0
+VICR AT TA = 125oC
+VICR AT TA = 25oC
+VICR AT TA = -55oC

-0.5
-1.0

+VOUT AT TA = 125oC
+VOUT AT TA = 25oC
+VOUT AT TA = -55oC

-1.5
-2.0
-2.5
-3.0
0

5

10
15
SUPPLY VOLTAGE (V+, V-)

20

-20

0

20
40
60
80
TEMPERATURE (oC)

100

120

25

1.5
-VICR AT TA = 125oC

1.0

-VICR AT TA = 25oC

0.5

-VOUT FOR
TA = -55oC to 125oC

0

-VICR AT TA = -55oC

-0.5
-1.0
-1.5
0

5

10
15
SUPPLY VOLTAGE (V+, V-)

20

FIGURE 8. OUTPUT VOLTAGE SWING CAPABILITY AND COMMON MODE INPUT VOLTAGE RANGE vs SUPPLY VOLTAGE

FN957 Rev.10.00
Jul 11, 2005

140

FIGURE 7. INPUT CURRENT vs TEMPERATURE

INPUT AND OUTPUT VOLTAGE EXCURSIONS
FROM TERMINAL 4 (V-)

INPUT AND OUTPUT VOLTAGE EXCURSIONS
FROM TERMINAL 7 (V+)

FIGURE 6. OPEN LOOP VOLTAGE GAIN AND PHASE vs
FREQUENCY

-40

Page 10 of 24

25

CA3140, CA3140A

OFFSET VOLTAGE SHIFT (mV)

7

TA = 125oC
FOR METAL CAN PACKAGES
DIFFERENTIAL DC VOLTAGE
(ACROSS TERMINALS 2 AND 3) = 2V
OUTPUT STAGE TOGGLED

6
5
4
3
2

DIFFERENTIAL DC VOLTAGE
(ACROSS TERMINALS 2 AND 3) = 0V
OUTPUT VOLTAGE = V+ / 2

1
0

0

500

1000 1500 2000 2500 3000 3500 4000 4500
TIME (HOURS)

FIGURE 9. TYPICAL INCREMENTAL OFFSET VOLTAGE
SHIFT vs OPERATING LIFE

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.

FN957 Rev.10.00
Jul 11, 2005

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, VABC (voltage between Terminals 5 and 4 of the
CA3080A of the function generator). Therefore, six decades
represent 360mV change in VABC .
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 VABC 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 D1 through D4. Positive feedback via D5 and D6
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.

Page 11 of 24

CA3140, CA3140A
CENTERING
-15V 10k

7.5k

+15V

360
3

7

+

-

2

4
5

2M

15k

+15V

51
pF

7-60
pF

-15V

39k

120

-15V

+
CA3140

3

-

2

HIGH
FREQ.
SHAPE

FREQUENCY
ADJUSTMENT

10k

0.1
F

5.1k

OUTPUT
AMPLIFIER

+15V

THIS NETWORK IS USED WHEN THE
OPTIONAL BUFFER CIRCUIT IS NOT USED

62k

10k

-

2
11k
11k
10k

-15V
2k

+15V

5

6

4

100k
FROM BUFFER METER
DRIVER (OPTIONAL)

0.1
F

7

6

CA3080A

360

SYMMETRY
-15V

+15V

HIGH
FREQUENCY
LEVEL
910k
7-60pF

EXTERNAL
OUTPUT

EXTERNAL
OUTPUT

7
6

CA3080
+
4

3

2.7k
-15V

13k

TO
SINE WAVE
SHAPER

TO OUTPUT
AMPLIFIER

1N914

FIGURE 10A. CIRCUIT

FREQUENCY
ADJUSTMENT

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.

+15V

METER DRIVER
AND BUFFER
AMPLIFIER

Bottom Trace: Output of “Log” generator; 10V/Div., 500ms/Div.
FIGURE 10B. FIGURE FUNCTION GENERATOR SWEEPING

POWER
SUPPLY 15V

M

-15V

FUNCTION
GENERATOR
WIDEBAND
LINE DRIVER

SINE WAVE
SHAPER

51

SWEEP
GENERATOR

FINE
RATE

GATE DC LEVEL
SWEEP ADJUST
OFF INT.

COARSE
RATE

1V/Div., 1s/Div.

EXT.

EXTERNAL
INPUT

SWEEP
LENGTH

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

V-

V-

FIGURE 10D. INTERCONNECTIONS

FIGURE 10. FUNCTION GENERATOR

FN957 Rev.10.00
Jul 11, 2005

Page 12 of 24

CA3140, CA3140A

500k
FREQUENCY
ADJUSTMENT
10k
SWEEP IN

FREQUENCY
CALIBRATION
MAXIMUM
620k
7
51k
3

6

CA3140
3M

-

2

4.7k
4

2k

+15V

0.1F

METER
SENSITIVITY
ADJUSTMENT

12k
FREQUENCY 2.4k
CALIBRATION
MINIMUM
2.5
k

0.1F

620

9

-15V

2k

7

6

R1
10k

14

METER
POSITION
ADJUSTMENT

3.6k 13

3/ OF CA3086
5

10k
EXTERNAL
OUTPUT

D4
5

D3

12

6

7
-15V
R3 10k
D1

9.1k

TO
WIDEBAND
OUTPUT
AMPLIFIER

SUBSTRATE
OF CA3019

1M

100
k

10

4

+15V

510
8

-

0.1F

1k

11

6

CA3140
2

5.6k
7.5k

7

+

3
5.1k

200A
M METER

510

-15V

+15V

TO CA3080A
OF FUNCTION CA3080A
GENERATOR
(FIGURE 10)
4
5

+

8
D6

9

1

3

4

2
D2

430
R2
1k

D
CA3019 5
DIODE ARRAY

-15V

FIGURE 11. METER DRIVER AND BUFFER AMPLIFIER

FIGURE 12. SINE WAVE SHAPER

750k
“LOG”
SAWTOOTH 18M
1N914

100k
100k FINE
RATE

1M
22M
SAWTOOTH
SYMMETRY

1N914
0.47F
0.047F

8.2k

+15V SAWTOOTH AND
RAMP LOW LEVEL
SET (-14.5V)

COARSE
RATE

4700pF

50k
75k

470pF

7

2

-

3

CA3140
+
4

51k

SAWTOOTH

+15V
0.1
F

“LOG”+15V

6

50k
LOG
RATE
ADJUST

-15V
43k

10k
10k

7

-

3

CA3140
+
4

100k
TO OUTPUT 2
AMPLIFIER

30k

0.1
F

+15V
36k

TRIANGLE

6

10k

GATE
PULSE
OUTPUT

-15V

EXTERNAL OUTPUT

TO FUNCTION GENERATOR “SWEEP IN”
SWEEP WIDTH

-15V
3

6

CA3140

LOGVIO

2

-

5

1

51k

4

6.8k

91k

10k
TRIANGLE

25k
3.9
100

+15V

7

+

-15V
390

5

1
4

2

TRANSISTORS
FROM CA3086
ARRAY

SAWTOOTH
“LOG”

3

FIGURE 13. SWEEPING GENERATOR

FN957 Rev.10.00
Jul 11, 2005

Page 13 of 24

CA3140, CA3140A
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 R1, followed
by an adjustment of R2. The final slope is established by
adjusting R3, 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.

REFERENCE
VOLTAGE

VOLTAGE
ADJUSTMENT
3

+

7

CA3140

INPUT
2

-

6

REGULATED
OUTPUT

4

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 18VP-P
output open circuited, or 9VP-P output when terminated in 50.
The slew rate required of this amplifier is 28V/s (18VP-P x  x
0.5MHz).
+15V

+

SIGNAL
LEVEL
ADJUSTMENT
2.5k
200

3

-

8

4

-

+
+15V
3k
-15V
200

2.4pF
2pF

1.8k

2.2
k

2N3053

1N914

2.7

1N914

2.7

6

CA3140
2

50F
25V

7

+

1
OUTPUT
DC LEVEL
ADJUSTMENT

-

50F
25V

2.2
k

51

OUT

2W

2N4037
-15V

NOMINAL BANDWIDTH = 10MHz
tr = 35ns

FIGURE 14. WIDEBAND OUTPUT AMPLIFIER

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).

FN957 Rev.10.00
Jul 11, 2005

FIGURE 15. BASIC SINGLE SUPPLY VOLTAGE REGULATOR
SHOWING VOLTAGE FOLLOWER CONFIGURATION

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 ICBO levels will also prevent
the output voltage from reaching zero because there is a finite
voltage drop (VCESAT) 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.

Page 14 of 24

CA3140, CA3140A
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

+30V

3

2N6385
CURRENT
POWER DARLINGTON LIMITING
ADJUST
D2201
2
75

1k

OUTPUT
0.1  24V
AT 1A

1k

100
7

8

1k
56pF
2

6
2.7k 10F

CA3140

+

5

-

1

100k

INPUT
+

2.2k

-

10 11

1 2

9

3

8 7

5

6

4

+30V

1k 200
1

12

2N2102
7

+

2.7k 10F

5

-

+

100k

-

13

+

2.2k

250F

0.01F

-

10 11

1 2

9

3

8 7

5

6

4

12

180k

1k

82k

3
4

5F 50k
14

VOLTAGE
ADJUST
100k

+

-

250F

0.01F
13

CA3086

CA3086

1k

1k

62k

62k
HUM AND NOISE OUTPUT <200VRMS
(MEASUREMENT BANDWIDTH ~10MHz)
LINE REGULATION 0.1%/V

1

INPUT

100k

56pF

CA3140

6
82k

VOLTAGE
ADJUST

8

1k
2

3

14

3k

100k
3

4

5F 50k

100k

180k

1k

OUTPUT  0V TO 25V
25V AT 1A
“FOLDS BACK”
TO 40mA

“FOLDBACK” CURRENT
LIMITER
2N5294
D2201
2
3

2
2N2102

1

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.

1

1k

3k

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.

LOAD REGULATION
(NO LOAD TO FULL LOAD)
<0.02%

FIGURE 16. REGULATED POWER SUPPLY

5V/Div., 1s/Div.

FIGURE 18A. SUPPLY TURN-ON AND TURNOFF
CHARACTERISTICS

HUM AND NOISE OUTPUT <200VRMS
(MEASUREMENT BANDWIDTH ~10MHz)
LINE REGULATION 0.1%/V

LOAD REGULATION
(NO LOAD TO FULL LOAD)
<0.02%

FIGURE 17. REGULATED POWER SUPPLY WITH “FOLDBACK”
CURRENT LIMITING

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

FN957 Rev.10.00
Jul 11, 2005

Page 15 of 24

CA3140, CA3140A
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.

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.

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.

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.

FOR SINGLE SUPPLY

NOTES:

+30V
2.2M

5. 20dB Flat Position Gain.
7

0.005F
5.1
M

3

+
CA3140

2

-

6. 15dB Bass and Treble Boost and Cut
at 100Hz and 10kHz, respectively.

0.1F

7. 25VP-P output at 20kHz.

6

8. -3dB at 24kHz from 1kHz reference.

4
BOOST

2.2M

0.1
F

0.012F

TREBLE
CUT
200k
(LINEAR) 0.001F

18k

100
pF

FOR DUAL SUPPLIES
+15V
0.005F

100pF

5.1M
0.022F
2F
- +

3

7
+
CA3140

2

4

0.0022F

0.1F
6
0.1F

-15V

10k

1M
100k
CCW (LOG)
BOOST
BASS
CUT
TONE CONTROL NETWORK

TONE CONTROL NETWORK

FIGURE 19. TONE CONTROL CIRCUIT USING CA3130 SERIES (20dB MIDBAND GAIN)
FOR SINGLE SUPPLY
BOOST
0.047F

BASS
CUT
(LINEAR)
240k
5M
240k
750
pF

2.2M

750
pF

+15V
7
3

2.2M
20pF
51k

5M
51k
(LINEAR)
BOOST TREBLE
CUT
TONE CONTROL NETWORK

FOR DUAL SUPPLIES

+32V

0.1
F

2.2
M 2

+
CA3140

4

0.1
F
6

0.047F

TONE CONTROL
NETWORK

3

7
+
CA3140

2

-


9. 15dB Bass and Treble Boost and Cut at 100Hz and 10kHz, Respectively.
10. 25VP-P Output at 20kHz.
11. -3dB at 70kHz from 1kHz Reference.
12. 0dB Flat Position Gain.

4

0.1F
6
0.1F

-15V

FIGURE 20. BAXANDALL TONE CONTROL CIRCUIT USING CA3140 SERIES

FN957 Rev.10.00
Jul 11, 2005

Page 16 of 24

CA3140, CA3140A
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 R1 = R2 = R and
C1 = C2 = C, the frequency equation reduces to the familiar
f = 1/(2RC) and the gain required for oscillation, AOSC is
equal to 3. Note that if C2 is increased by a factor of four and
R2 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.
C2

R2

NOTES:

+
OUTPUT

RF
C1

R1

RS

1000pF
3
C1 2
1000
pF

R1

RF
A CL = 1 + -------RS

FIGURE 21. BASIC WIEN BRIDGE OSCILLATOR CIRCUIT
USING AN OPERATIONAL AMPLIFIER

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, RS, is commonly replaced with some variable
resistance element. Thus, through some control means, the
value of RS 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 (RF 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 16VP-P .

7
+
CA3140

4

0.1F

CA3109
DIODE
ARRAY

6
SUBSTRATE
OF CA3019

8

9

2

6

0.1F

7
0.1F

-15V

7.5k

5

3

4

50Hz, R =
100Hz, R =
1kHz, R =
10kHz, R =
30kHz, R =

3.3M
1.6M
160M
16M
5.1M

3.6k
500

FIGURE 22. WIEN BRIDGE OSCILLATOR CIRCUIT USING
CA3140

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.
0

30k

SAMPLE

STROBE
-15

1N914

HOLD

+15V
1N914
INPUT

2k

+15V

5
+

3

CA3080A

-

2

0.1F

7
6

4

0.1F
2k

3

+
CA3140

2

5

1

6
0.1
F

4

100k

-15V
200pF

3.5k

7

-15V

2k

C1

200pF

2k

400

0.1F
30pF
SIMULATED LOAD
NOT REQUIRED

FIGURE 23. SAMPLE AND HOLD CIRCUIT

In this circuit, the storage compensation capacitance (C1) is
only 200pF. Larger value capacitors provide longer “hold”
periods but with slower slew rates. The slew rate is:
dv
I
------ = ---- = 0.5mA  200pF = 2.5V  s
dt
C
NOTE:
13. AN6668 “Applications of the CA3080 and CA 3080A High
Performance Operational Transconductance Amplifiers”.

FN957 Rev.10.00
Jul 11, 2005

1

R1 = R2 = R

1
f = ------------------------------------------2 R 1 C 1 R 2 C 2
C1 R2
A OSC = 1 + ------- + ------C2 R1

+15V

R2
C2

OUTPUT
19VP-P TO 22VP-P
THD <0.3%

Page 17 of 24

CA3140, CA3140A
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 C1
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 RL. This load current is increased by the
multiplication factor R2/R1, 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.
R1
10k

IL x

R2
R1

+15V

7
+
CA3140

3
M

-

2
POWER
SUPPLY

5

4

1

0.1F
6
0.1F

R2
10M

IL
RL

100k

Top Trace: Output; 50mV/Div., 200ns/Div.
Bottom Trace: Input; 50mV/Div., 200ns/Div.

4.3k
-15V

FIGURE 25. BASIC CURRENT AMPLIFIER FOR LOW CURRENT
MEASUREMENT 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.

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

FN957 Rev.10.00
Jul 11, 2005

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 fullwave 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 -R2/R1. 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”.

Page 18 of 24

CA3140, CA3140A
+15V

R2
5k

+15V
0.1F

R1
10k

CA3140
+

3

8

0.1F

7

-

2

5

1

7

10k
INPUT

3

CA3140
6

4

2

1N914
10k
R3

100k
OFFSET
ADJUST

PEAK
ADJUST
10k

6

-

100pF

4

2k

0.1F
-15V
2k

R2
R3
GAIN = ------- = X = ----------------------------R1
R1 R2 + R3

SIMULATED
LOAD

+

BW (-3dB) = 4.5MHz
SR = 9V/s

0.05F

FIGURE 28A. TEST CIRCUIT

2

X+X
R 3 =  ----------------- R 1
 1–X 
R2
5k
FOR X = 0.5 --------------- = ------R1
10k
0.75
R 3 = 10k  ----------- = 15k
 0.5 

20VP-P Input BW (-3dB) = 290kHz, DC Output (Avg) = 3.2V

OUTPUT
0

Top Trace: Output; 50mV/Div., 200ns/Div.
Bottom Trace: Input; 50mV/Div., 200ns/Div.

INPUT
0

FIGURE 28B. SMALL SIGNAL RESPONSE

FIGURE 26. SINGLE SUPPLY, ABSOLUTE VALUE, IDEAL
FULL WAVE RECTIFIER WITH ASSOCIATED
WAVEFORMS
+15V
7

RS
3
1M

+
CA3140

2

0.01F

6

-

NOISE VOLTAGE
OUTPUT

4
0.01F

30.1k

(Measurement made with Tektronix 7A13 differential amplifier.)
Top Trace: Output Signal; 5V/Div., 5s/Div.

-15V

Center Trace: Difference Signal; 5mV/Div., 5s/Div.
BW (-3dB) = 140kHz
TOTAL NOISE VOLTAGE
(REFERRED TO INPUT) = 48V (TYP)

1k

FIGURE 27. TEST CIRCUIT AMPLIFIER (30dB GAIN) USED FOR
WIDEBAND NOISE MEASUREMENT

FN957 Rev.10.00
Jul 11, 2005

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

Page 19 of 24

CA3140, CA3140A

Typical Performance Curves
20
GAIN BANDWIDTH PRODUCT (MHz)

OPEN-LOOP VOLTAGE GAIN (dB)

RL = 2k

TA = -55oC
25oC
125oC

125
100
75
50
25
0

0

5

10

15

20

RL = 2k
CL = 100pF
10

TA = -55oC

1

25

0

5

SUPPLY VOLTAGE (V)

QUIESCENT SUPPLY CURRENT (mA)

TA = -55oC

SLEW RATE (V/s)

15
10
5

5

10
15
SUPPLY VOLTAGE (V)

20

25

COMMON-MODE REJECTION RATIO (dB)

OUTPUT SWING (VP-P)

25
20
15
10
5

100K

7
6

TA = -55oC

25oC

5

125oC

4
3
2
1
0

0

5

10

15

20

25

FIGURE 32. QUIESCENT SUPPLY CURRENT vs SUPPLY
VOLTAGE AND TEMPERATURE

SUPPLY VOLTAGE: VS =15V
TA = 25oC

1M

FREQUENCY (Hz)

FIGURE 33. MAXIMUM OUTPUT VOLTAGE SWING vs
FREQUENCY

FN957 Rev.10.00
Jul 11, 2005

25

SUPPLY VOLTAGE (V)

FIGURE 31. SLEW RATE vs SUPPLY VOLTAGE AND
TEMPERATURE

0
10K

20

RL = 

25oC
125oC

0

15

FIGURE 30. GAIN BANDWIDTH PRODUCT vs SUPPLY
VOLTAGE AND TEMPERATURE

RL = 2k
CL = 100pF

0

10

SUPPLY VOLTAGE (V)

FIGURE 29. OPEN-LOOP VOLTAGE GAIN vs SUPPLY
VOLTAGE AND TEMPERATURE

20

25oC
125oC

4M

120 SUPPLY VOLTAGE: VS =15V
TA = 25oC
100
80
60
40
20
0
101

102

103
104
105
FREQUENCY (Hz)

106

107

FIGURE 34. COMMON MODE REJECTION RATIO vs FREQUENCY

Page 20 of 24

CA3140, CA3140A

Typical Performance Curves

(Continued)
SUPPLY VOLTAGE: VS =15V
TA = 25oC

SUPPLY VOLTAGE: VS =15V
TA = 25oC
POWER SUPPLY REJECTION RATIO (dB)

EQUIVALENT INPUT NOISE VOLTAGE (nV/Hz)

1000

100

10

1

1

101

102
103
FREQUENCY (Hz)

104

FIGURE 35. EQUIVALENT INPUT NOISE VOLTAGE vs
FREQUENCY

FN957 Rev.10.00
Jul 11, 2005

105

100
+PSRR

80

60

40

20

-PSRR

POWER SUPPLY REJECTION RATIO
(PSRR) = VIO/VS

0
101

102

103
104
105
FREQUENCY (Hz)

106

107

FIGURE 36. POWER SUPPLY REJECTION RATIO vs FREQUENCY

Page 21 of 24

CA3140, CA3140A

Metallization Mask Layout

0
61

10

20

30

40

50

60

65

60

50

40
58-66
(1.473-1.676)

30

20

10

0

4-10
(0.102-0.254)
62-70
(1.575-1.778)

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 57o 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.

FN957 Rev.10.00
Jul 11, 2005

Page 22 of 24

CA3140, CA3140A

Dual-In-Line Plastic Packages (PDIP)
E8.3 (JEDEC MS-001-BA ISSUE D)

N

8 LEAD DUAL-IN-LINE PLASTIC PACKAGE

E1

INDEX
AREA

1 2 3

INCHES

N/2
-B-

-AD

E

BASE
PLANE

-C-

SEATING
PLANE

A2

A
L

D1

e

B1

D1

B
0.010 (0.25) M

A1

eC
C A B S

MILLIMETERS

SYMBOL

MIN

MAX

MIN

MAX

NOTES

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

-

C
L

B1

0.045

0.070

1.15

1.77

8, 10

eA

C

0.008

0.014

0.204

C

D

0.355

0.400

9.01

eB

NOTES:
1. Controlling Dimensions: INCH. In case of conflict between
English and Metric dimensions, the inch dimensions control.

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

eA

0.300 BSC

3. Symbols are defined in the “MO Series Symbol List” in Section
2.2 of Publication No. 95.

eB

-

L

0.115

5. D, D1, and E1 dimensions do not include mold flash or protrusions. Mold flash or protrusions shall not exceed 0.010 inch
(0.25mm).
6. E and eA are measured with the leads constrained to be perpendicular to datum -C- .

N

8

2.54 BSC

-

7.62 BSC

0.430

-

0.150

2.93

6

10.92

7

3.81

4

8

9
Rev. 0 12/93

7. eB and eC are measured at the lead tips with the leads unconstrained. eC 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).

FN957 Rev.10.00
Jul 11, 2005

5

D1

2. Dimensioning and tolerancing per ANSI Y14.5M-1982.

4. Dimensions A, A1 and L are measured with the package seated
in JEDEC seating plane gauge GS-3.

0.355
10.16

Page 23 of 24

CA3140, CA3140A

Small Outline Plastic Packages (SOIC)
M8.15 (JEDEC MS-012-AA ISSUE C)

N
INDEX
AREA

0.25(0.010) M

H

8 LEAD NARROW BODY SMALL OUTLINE PLASTIC
PACKAGE

B M

E

INCHES
-B-

1

2

SYMBOL

3

L
SEATING PLANE

-A-

h x 45o

A

D
-C-

µ

e
B
0.25(0.010) M

C
0.10(0.004)

C A M

B S

1. Symbols are defined in the “MO Series Symbol List” in Section 2.2 of
Publication Number 95.

MILLIMETERS
MIN

MAX

NOTES

A

0.0532

0.0688

1.35

1.75

-

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

0.050 BSC

5.80

-

0.2284

h

0.0099

0.0196

0.25

0.50

5

L

0.016

0.050

0.40

1.27

6

8o

0o



0.2440

1.27 BSC

H

N

NOTES:

MAX

A1

e

A1

MIN

8
0o

6.20

8

-

7
8o

Rev. 0 12/93

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. Interlead 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.

© Copyright Intersil Americas LLC 2002-2005. All Rights Reserved.
All trademarks and registered trademarks are the property of their respective owners.

For additional products, see www.intersil.com/en/products.html
Intersil products are manufactured, assembled and tested utilizing ISO9001 quality systems as noted
in the quality certifications found at www.intersil.com/en/support/qualandreliability.html
Intersil products are sold by description only. Intersil may modify the circuit design and/or specifications of products at any time without notice, provided that such
modification does not, in Intersil's sole judgment, affect the form, fit or function of the product. Accordingly, the reader is cautioned to verify that datasheets 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

FN957 Rev.10.00
Jul 11, 2005

Page 24 of 24



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Keywords                        : CA3140A, CA3140, BiMOS operational amplifier, 4.5MHz operational amplifier, MOSFET input/bipolar output, 4.5MHz, BiMOS Operational Amplifier with MOSFET Input/Bipolar Output
Modify Date                     : 2017:12:07 10:02:40Z
Subject                         : 4.5MHz, BiMOS Operational Amplifier with MOSFET Input/Bipolar Output
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