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. Short circuit may be applied to ground or to either supply.
2.
θ
JA
is measured with the component mounted on an evaluation PC board in free air.
Electrical Specifications
PARAMETER
Input Offset Voltage
Input Offset Voltage
Temperature Drift
Input Offset Current
Input Current
Large-Signal Voltage Gain
T
A
= 25
o
C, V+ = 15V, V- = 0V, Unless Otherwise Specified
TEST
CONDITIONS
V
S
=
±7.5V
CA3130
MIN
-
-
V
S
=
±7.5V
V
S
=
±7.5V
V
O
= 10V
P-P
R
L
= 2kΩ
-
-
50
94
70
0
V
S
=
±7.5V
R
L
= 2kΩ
R
L
= 2kΩ
R
L
=
∞
R
L
=
∞
-
12
-
14.99
-
12
12
-
-
TYP
8
10
0.5
5
320
110
90
-0.5 to 12
32
13.3
0.002
15
0
22
20
10
2
MAX
15
-
30
50
-
-
-
10
320
-
0.01
-
0.01
45
45
15
3
MIN
-
-
-
-
50
94
80
0
-
12
-
14.99
-
12
12
-
-
CA3130A
TYP
2
10
0.5
5
320
110
90
-0.5 to 12
32
13.3
0.002
15
0
22
20
10
2
MAX
5
-
20
30
-
-
-
10
150
-
0.01
-
0.01
45
45
15
3
UNITS
mV
µV/
o
C
pA
pA
kV/V
dB
dB
V
µV/V
V
V
V
V
mA
mA
mA
mA
SYMBOL
|V
IO
|
∆V
IO
/∆T
|I
IO
|
I
I
A
OL
Common-Mode
Rejection Ratio
Common-Mode Input
Voltage Range
Power-Supply
Rejection Ratio
Maximum Output Voltage
CMRR
V
ICR
∆V
IO
/∆V
S
V
OM
+
V
OM
-
V
OM
+
V
OM
-
Maximum Output Current
I
OM
+ (Source) at V
O
= 0V
I
OM
- (Sink) at V
O
= 15V
Supply Current
I+
I+
V
O
= 7.5V,
R
L
=
∞
V
O
= 0V,
R
L
=
∞
2
CA3130, CA3130A
Electrical Specifications
Typical Values Intended Only for Design Guidance, V
SUPPLY
=
±
7.5V, T
A
= 25
o
C
Unless Otherwise Specified
SYMBOL
TEST CONDITIONS
10kΩ Across Terminals 4 and 5 or
4 and 1
R
I
C
I
e
N
f = 1MHz
BW = 0.2MHz, R
S
= 1MΩ
(Note 3)
C
C
= 0
C
C
= 47pF
CA3130,
CA3130A
±22
1.5
4.3
23
15
4
UNITS
mV
TΩ
pF
µV
MHz
MHz
PARAMETER
Input Offset Voltage Adjustment Range
Input Resistance
Input Capacitance
Equivalent Input Noise Voltage
Open Loop Unity Gain Crossover Frequency
(For Unity Gain Stability
≥47pF
Required.)
Slew Rate:
Open Loop
Closed Loop
Transient Response:
Rise Time
Overshoot
Settling Time (To <0.1%, V
IN
= 4V
P-P
)
NOTE:
f
T
SR
C
C
= 0
C
C
= 56pF
C
C
= 56pF,
C
L
= 25pF,
R
L
= 2kΩ
(Voltage Follower)
30
10
V/µs
V/µs
t
r
OS
t
S
0.09
10
1.2
µs
%
µs
3. Although a 1MΩ source is used for this test, the equivalent input noise remains constant for values of R
S
up to 10MΩ.
Electrical Specifications
PARAMETER
Input Offset Voltage
Input Offset Current
Input Current
Common-Mode Rejection Ratio
Large-Signal Voltage Gain
Typical Values Intended Only for Design Guidance, V+ = 5V, V- = 0V, T
A
= 25
o
C
Unless Otherwise Specified (Note 4)
SYMBOL
V
IO
I
IO
I
I
CMRR
A
OL
V
O
= 4V
P-P
, R
L
= 5kΩ
TEST CONDITIONS
CA3130
8
0.1
2
80
100
100
CA3130A
2
0.1
2
90
100
100
0 to 2.8
300
500
200
UNITS
mV
pA
pA
dB
kV/V
dB
V
µA
µA
µV/V
Common-Mode Input Voltage Range
Supply Current
V
ICR
I+
V
O
= 5V, R
L
=
∞
V
O
= 2.5V, R
L
=
∞
0 to 2.8
300
500
200
Power Supply Rejection Ratio
NOTE:
∆V
IO
/∆V+
4. Operation at 5V is not recommended for temperatures below 25
o
C.
3
CA3130, CA3130A
Schematic Diagram
BIAS CIRCUIT
CURRENT SOURCE FOR
Q
6
AND Q
7
Q
1
D
1
Z
1
8.3V
R
1
40kΩ R
2
5kΩ
INPUT STAGE
NON-INV.
INPUT
+
INV.-INPUT
2
3
D
5
D
6
(NOTE 5) D
7
D
8
OUTPUT
STAGE
Q
6
Q
7
SECOND
STAGE
D
2
D
3
D
4
Q
4
Q
5
Q
2
“CURRENT SOURCE
LOAD” FOR Q
11
7
V+
Q
3
Q
8
OUTPUT
6
-
R
3
1kΩ
Q
9
Q
10
Q
11
R
5
1kΩ
R
6
1kΩ
R
4
1kΩ
Q
12
5
OFFSET NULL
1
COMPENSATION
8
STROBING
4
V-
NOTE:
5. Diodes D
5
through D
8
provide gate-oxide protection for MOSFET input stage.
Application Information
Circuit Description
Figure 1 is a block diagram of the CA3130 Series CMOS
Operational Amplifiers. The input terminals may be operated
down to 0.5V below the negative supply rail, and the output
can be swung very close to either supply rail in many
applications. Consequently, the CA3130 Series circuits are
ideal for single-supply operation. Three Class A amplifier
stages, having the individual gain capability and current
consumption shown in Figure 1, provide the total gain of the
CA3130. A biasing circuit provides two potentials for
common use in the first and second stages. Terminal 8 can
be used both for phase compensation and 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 potential at Terminal 6 essentially rises to
the positive supply-rail potential at Terminal 7. This condition
of essentially zero current drain in the output stage under the
strobed “OFF” condition can only be achieved when the
4
ohmic load resistance presented to the amplifier is very high
(e.g.,when the amplifier output is used to drive CMOS digital
circuits in Comparator applications).
Input Stage
The circuit of the CA3130 is shown in the schematic diagram.
It consists of a differential-input stage using PMOS field-effect
transistors (Q
6
, Q
7
) working into a mirror-pair of bipolar
transistors (Q
9
, Q
10
) functioning as load resistors together
with resistors R
3
through R
6
. The mirror-pair transistors also
function as a differential-to-single-ended converter to provide
base drive to the second-stage bipolar transistor (Q
11
). Offset
nulling, when desired, can be effected by connecting a
100,000Ω potentiometer across Terminals 1 and 5 and the
potentiometer slider arm to Terminal 4. Cascade-connected
PMOS transistors Q
2
, Q
4
are the constant-current source for
the input stage. The biasing circuit for the constant-current
source is subsequently described. The small diodes D
5
CA3130, CA3130A
through D
8
provide gate-oxide protection against high-voltage
transients, including static electricity during handling for Q
6
and Q
7
.
CA3130
200µA
1.35mA
200µA
8mA
(NOTE 5)
0mA
(NOTE 7)
V+
7
BIAS CKT.
+
3
INPUT
2
A
V
≈
5X
A
V
≈
6000X
A
V
≈
30X
OUTPUT
6
V-
4
5
1
C
C
COMPENSATION
(WHEN REQUIRED)
8
STROBE
At total supply voltages somewhat less than 8.3V, zener
diode Z
1
becomes nonconductive and the potential,
developed across series-connected R
1
, D
1
-D
4
, and Q
1
,
varies directly with variations in supply voltage.
Consequently, the gate bias for Q
4
, Q
5
and Q
2
, Q
3
varies in
accordance with supply-voltage variations. This variation
results in deterioration of the power-supply-rejection ratio
(PSRR) at total supply voltages below 8.3V. Operation at
total supply voltages below about 4.5V results in seriously
degraded performance.
Output Stage
The output stage consists of a drain-loaded inverting
amplifier using CMOS transistors operating in the Class A
mode. When operating into very high resistance loads, the
output can be swung within millivolts of either supply rail.
Because the output stage is a drain-loaded amplifier, its gain
is dependent upon the load impedance. The transfer
characteristics of the output stage for a load returned to the
negative supply rail are shown in Figure 2. Typical op amp
loads are readily driven by the output stage. Because large-
signal excursions are non-linear, requiring feedback for good
waveform reproduction, transient delays may be
encountered. As a voltage follower, the amplifier can achieve
0.01% accuracy levels, including the negative supply rail.
NOTE:
8. For general information on the characteristics of CMOS transis-
tor-pairs in linear-circuit applications, see File Number 619, data
sheet on CA3600E “CMOS Transistor Array”.
OUTPUT VOLTAGE (TERMINALS 4 AND 8) (V)
17.5
15
12.5
1kΩ
10
7.5
5
2.5
0
0
2.5
5
7.5
10
12.5
15
17.5
20
22.5
GATE VOLTAGE (TERMINALS 4 AND 8) (V)
500Ω
SUPPLY VOLTAGE: V+ = 15, V- = 0V
T
A
= 25
o
C
LOAD RESISTANCE = 5kΩ
2kΩ
-
OFFSET
NULL
NOTES:
6. Total supply voltage (for indicated voltage gains) = 15V with input
terminals biased so that Terminal 6 potential is +7.5V above Ter-
minal 4.
7. Total supply voltage (for indicated voltage gains) = 15V with out-
put terminal driven to either supply rail.
FIGURE 1. BLOCK DIAGRAM OF THE CA3130 SERIES
Second-Stage
Most of the voltage gain in the CA3130 is provided by the
second amplifier stage, consisting of bipolar transistor Q
11
and its cascade-connected load resistance provided by
PMOS transistors Q
3
and Q
5
. The source of bias potentials
for these PMOS transistors is subsequently described. Miller
Effect compensation (roll-off) is accomplished by simply
connecting a small capacitor between Terminals 1 and 8. A
47pF capacitor provides sufficient compensation for stable
unity-gain operation in most applications.
Bias-Source Circuit
At total supply voltages, somewhat above 8.3V, resistor R
2
and zener diode Z
1
serve to establish a voltage of 8.3V across
the series-connected circuit, consisting of resistor R
1
, diodes
D
1
through D
4
, and PMOS transistor Q
1
. A tap at the junction
of resistor R
1
and diode D
4
provides a gate-bias potential of
about 4.5V for PMOS transistors Q
4
and Q
5
with respect to
Terminal 7. A potential of about 2.2V is developed across
diode-connected PMOS transistor Q
1
with respect to Terminal
7 to provide gate bias for PMOS transistors Q
2
and Q
3
. It
should be noted that Q
1
is “mirror-connected (see Note 8)” to
both Q
2
and Q
3
. Since transistors Q
1
, Q
2
, Q
3
are designed to
be identical, the approximately 200µA current in Q
1
establishes a similar current in Q
2
and Q
3
as constant current
sources for both the first and second amplifier stages,
respectively.
FIGURE 2. VOLTAGE TRANSFER CHARACTERISTICS OF
CMOS OUTPUT STAGE
Input Current Variation with Common Mode Input
Voltage
As shown in the Table of Electrical Specifications, the input
current for the CA3130 Series Op Amps is typically 5pA at
T
A
= 25
o
C when Terminals 2 and 3 are at a common-mode
potential of +7.5V with respect to negative supply Terminal 4.
Figure 3 contains data showing the variation of input current