Datasheet CA3130T, CA3130M96, CA3130M, CA3130E, CA3130BT Datasheet (Harris Semiconductor)

...
Page 1
SEMICONDUCTOR
3-64
November 1996
CA3130, CA3130A
15MHz, BiMOS Operational Amplifier
with MOSFET Input/CMOS Output
Features
• MOSFET Input Stage Provides:
I
= 1.5 T (1.5 x 1012Ω) (Typ)
- Very Low I
I
= 5pA (Typ) at 15V Operation
= 2pA (Typ) at 5V Operation
• Ideal for Single-Supply Applications
• Common-Mode Input-Voltage Range Includes Negative Supply Rail; Input Terminals can be Swung
0.5V Below Negative Supply Rail
• CMOS Output Stage Permits Signal Swing to Either (or both) Supply Rails
Applications
• Ground-Referenced Single Supply Amplifiers
• Fast Sample-Hold Amplifiers
• Long-Duration Timers/Monostables
• High-Input-Impedance Comparators (Ideal Interface with Digital CMOS)
• High-Input-Impedance Wideband Amplifiers
• V oltage Followers (e.g. Follower f or Single-Supply D/A Converter)
• V oltage Regulators (P ermits Contr ol of Output Voltage Down to 0V)
• Peak Detectors
• Single-Supply Full-Wave Precision Rectifiers
• Photo-Diode Sensor Amplifiers
Description
CA3130A and CA3130 are op amps that combine the advantage of both CMOS and bipolar transistors.
Gate-protected P-Channel MOSFET (PMOS) transistors are used in the input circuit to provide very-high-input impedance, very-low-input current, and exceptional speed performance. The use of PMOS transistors in the input stage results in common-mode input-voltage capability down to
0.5V below the negative-supply terminal, an important attribute in single-supply applications.
A CMOS transistor-pair, capable of swinging the output volt­age to within 10mV of either supply-voltage terminal (at very high values of load impedance), is employed as the output circuit.
The CA3130 Series circuits operate at supply voltages ranging from 5V to 16V, (±2.5V to ±8V). They can be phase compensated with a single external capacitor, and have ter­minals for adjustment of offset voltage for applications requiring offset-null capability. Terminal provisions are also made to permit strobing of the output stage.
The CA3130A offers superior input characteristics over those of the CA3130.
Pinouts
CA3131, CA3130A
(PDIP, SOIC)
TOP VIEW
CA3130, CA3130A
(METAL CAN)
TOP VIEW
OFFSET
INV.
NON-INV.
V-
1 2 3 4
8 7 6 5
STROBE V+ OUTPUT OFFSET
-
+
NULL INPUT INPUT
NULL
TAB
OUTPUT
INV.
V- AND CASE
OFFSET
NON-INV.
V
+
OFFSET
2
4
6
1
3
7
5
8
-
+
STROBE
PHASE COMPENSATION
NULL
INPUT
INPUT
NULL
Ordering Information
PART NO.
(BRAND)
TEMP.
RANGE
(oC) PACKAGE
PKG.
NO.
CA3130AE
-55 to 125 8 Ld PDIP
E8.3
CA3130AM
(3130A)
-55 to 125 8 Ld SOIC
M8.15
CA3130AM96
(3130A)
-55 to 125 8 Ld SOIC (Note)
M8.15
CA3130AT
-55 to 125 8 Pin Metal Can
T8.C
CA3130BT
-55 to 125 8 Pin Metal Can
T8.C
CA3130E
-55 to 125 8 Ld PDIP
E8.3
CA3130M
(3130)
-55 to 125 8 Ld SOIC
M8.15
CA3130M96
(3130)
-55 to 125 8 Ld SOIC (Note)
M8.15
CA3130T
-55 to 125 8 Pin Metal Can
T8.C
NOTE: Denotes Tape and Reel.
CAUTION: These devices are sensitive to electrostatic discharge. Users should follow proper IC Handling Procedures. Copyright
© Harris Corporation 1996
File Number 817.3
Page 2
3-65
Absolute Maximum Ratings Thermal Information
DC Supply Voltage (Between V+ And V- Terminals) . . . . . . . . . 16V
Differential Input Voltage. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8V
DC Input Voltage . . . . . . . . . . . . . . . . . . . . . . (V+ +8V) to (V- -0.5V)
Input-Terminal Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1mA
Output Short-Circuit Duration (Note 1). . . . . . . . . . . . . . . . Indefinite
Operating Conditions
Temperature Range . . . . . . . . . . . . . . . . . . . . . . . . -50oC to 125oC
Thermal Resistance (Typical, Note 2) θJA (oC/W) θJC (oC/W)
PDIP Package. . . . . . . . . . . . . . . . . . . 100 N/A
SOIC Package. . . . . . . . . . . . . . . . . . . 160 N/A
Metal Can Package. . . . . . . . . . . . . . . 170 85
Maximum Junction Temperature (Metal Can Package). . . . . . .175oC
Maximum Junction Temperature (Plastic Package) . . . . . . . . 150oC
Maximum Storage Temperature Range . . . . . . . . . -65oC to 150oC
Maximum Lead Temperature (Soldering 10s) . . . . . . . . . . . . . 300oC
(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. Short circuit may be applied to ground or to either supply.
2. θJA is measured with the component mounted on an evaluation PC board in free air.
Electrical Specifications T
A
= 25oC, V+ = 15V, V- = 0V, Unless Otherwise Specified
PARAMETER SYMBOL
TEST
CONDITIONS
CA3130 CA3130A
UNITSMIN TYP MAX MIN TYP MAX
Input Offset Voltage |V
IO
|V
S
= ±7.5V - 8 15 - 2 5 mV
Input Offset Voltage Temperature Drift
V
IO
/T - 10 - - 10 - µV/oC
Input Offset Current |I
IO
|V
S
= ±7.5V - 0.5 30 - 0.5 20 pA
Input Current I
I
VS = ±7.5V - 5 50 - 5 30 pA
Large-Signal Voltage Gain A
OL
VO = 10V
P-P
RL = 2k
50 320 - 50 320 - kV/V 94 110 - 94 110 - dB
Common-Mode Rejection Ratio
CMRR 70 90 - 80 90 - dB
Common-Mode Input Voltage Range
V
ICR
0 -0.5 to
12
10 0 -0.5 to
12
10 V
Power-Supply Rejection Ratio
V
IO
/VSVS = ±7.5V - 32 320 - 32 150 µV/V
Maximum Output Voltage V
OM
+R
L
= 2k 12 13.3 - 12 13.3 - V
V
OM
-R
L
= 2k - 0.002 0.01 - 0.002 0.01 V
V
OM
+R
L
= 14.99 15 - 14.99 15 - V
V
OM
-R
L
= - 0 0.01 - 0 0.01 V
Maximum Output Current I
OM
+ (Source) at VO = 0V 12 22 45 12 22 45 mA
I
OM
- (Sink) at VO = 15V 12 20 45 12 20 45 mA
Supply Current I+ V
O
= 7.5V,
RL =
- 10 15 - 10 15 mA
I+ V
O
= 0V,
RL =
-23-23mA
CA3130, CA3130A
Page 3
3-66
Electrical Specifications Typical Values Intended Only for Design Guidance, V
SUPPLY
= ±7.5V, TA = 25oC
Unless Otherwise Specified
PARAMETER SYMBOL TEST CONDITIONS
CA3130,
CA3130A UNITS
Input Offset Voltage Adjustment Range 10k Across Terminals 4 and 5
or 4 and 1
±22 mV
Input Resistance R
I
1.5 T
Input Capacitance C
I
f = 1MHz 4.3 pF
Equivalent Input Noise Voltage e
N
BW = 0.2MHz, RS = 1M (Note 3)
23 µV
Open Loop Unity Gain Crossover Frequency (For Unity Gain Stability 47pF Required.) f
T
CC = 0 15 MHz
CC = 47pF 4 MHz
Slew Rate: SR
CC = 0 30 V/µsOpen Loop
Closed Loop CC = 56pF 10 V/µs
Transient Response: CC = 56pF,
CL = 25pF, RL = 2k (Voltage Follower)
0.09 µsRise Time t
r
Overshoot OS 10 %
Settling Time (To <0.1%, VIN = 4V
P-P
)t
S
1.2 µs
NOTE:
3. Although a 1M source is used for this test, the equivalent input noise remains constant for values of RS up to 10MΩ.
Electrical Specifications Typical Values Intended Only for Design Guidance, V+ = 5V, V- = 0V, T
A
= 25oC
Unless Otherwise Specified (Note 4)
PARAMETER SYMBOL TEST CONDITIONS CA3130 CA3130A UNITS
Input Offset Voltage V
IO
82mV
Input Offset Current I
IO
0.1 0.1 pA
Input Current I
I
22pA
Common-Mode Rejection Ratio CMRR 80 90 dB
Large-Signal Voltage Gain A
OL
VO = 4V
P-P
, RL = 5k 100 100 kV/V
100 100 dB
Common-Mode Input Voltage Range V
ICR
0 to 2.8 0 to 2.8 V
Supply Current I+ VO = 5V, RL = 300 300 µA
VO = 2.5V, RL = 500 500 µA
Power Supply Rejection Ratio VIO/V+ 200 200 µV/V
NOTE:
4. Operation at 5V is not recommended for temperatures below 25oC.
CA3130, CA3130A
Page 4
3-67
Schematic Diagram
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 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
, Q7) working into a mirror-pair of bipolar tran-
sistors (Q
9
, Q10) functioning as load resistors together with
resistors R
3
through R6. The mirror-pair transistors also func­tion as a differential-to-single-ended conv erter to provide base drive to the second-stage bipolar transistor (Q
11
). Offset null­ing, when desired, can be effected by connecting a 100,000 potentiometer across Terminals 1 and 5 and the potentiome­ter slider arm to Terminal 4. Cascade-connected PMOS transistors Q
2
, Q4 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
through D
8
provide gate-oxide protection against high-voltage transients, including static electricity during handling for Q
6
and Q7.
3
2
1 8 4
6
7
Q
1
Q
2
Q
4
D
1
D
2
D
3
D
4
Q
3
Q
5
D5D
6
D7D
8
Q
9
Q
10
Q
6
Q
7
5
Z
1
8.3V
INPUT STAGE
R
3
1k
R
4
1k
R
6
1k
R
5
1k
NON-INV.
INPUT
INV.-INPUT
+
-
R
1
40k
5k
R
2
BIAS CIRCUIT
CURRENT SOURCE FOR
“CURRENT SOURCE
LOAD” FOR Q
11
Q6AND Q
7
V+
OUTPUT
OUTPUT STAGE
Q
8
Q
12
V-
Q
11
SECOND STAGE
OFFSET NULL
COMPENSATION STROBING
(NOTE 5)
NOTE:
5. Diodes D5 through D8 provide gate-oxide protection for MOSFET input stage.
CA3130, CA3130A
Page 5
3-68
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 Q5. 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 Z1 serve to establish a voltage of 8.3V across the series-connected circuit, consisting of resistor R
1
, diodes
D
1
through D4, and PMOS transistor Q1. A tap at the junction
of resistor R
1
and diode D4 provides a gate-bias potential of
about 4.5V for PMOS transistors Q
4
and Q5 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 Q3. It
should be noted that Q
1
is “mirror-connected (see Note 8)” to
both Q
2
and Q3. Since transistors Q1, Q2, Q3 are designed to
be identical, the approximately 200µA current in Q
1
estab-
lishes a similar current in Q
2
and Q3 as constant current sources for both the first and second amplifier stages, respec­tively.
At total supply voltages somewhat less than 8.3V, zener diode Z
1
becomes nonconductive and the potential,
developed across series-connected R
1
, D1-D4, and Q1, var­ies directly with variations in supply voltage. Consequently, the gate bias for Q
4
, Q5 and Q2, Q3 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 wa ve­form 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 transis­tor-pairs in linear-circuit applications, see File Number 619, data sheet on CA3600E “CMOS Transistor Array”.
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
= 25oC 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 as a function of common-mode input voltage at T
A
=25oC. These data show that circuit designers can advantageously exploit these characteristics to design circuits which typically require an input current of less than 1pA, provided the com­mon-mode input voltage does not exceed 2V. As previously noted, the input current is essentially the result of the leakage current through the gate-protection diodes in the input circuit and, therefore, a function of the applied voltage. Although the finite resistance of the glass terminal-to-case insulator of the
3
2
7
4
815
6
BIAS CKT.
COMPENSATION
(WHEN REQUIRED)
AV≈ 5X
AV≈
A
V
6000X
30X
INPUT
+
-
200µA 200µA
1.35mA
8mA 0mA
V+
OUTPUT
V-
STROBE
C
C
OFFSET
NULL
CA3130
(NOTE 7)
(NOTE 5)
NOTES:
6. Total supply voltage (for indicated voltage gains) = 15V with input terminals biased so that Terminal 6 potential is +7.5V above Ter­minal 4.
7. Total supply voltage (for indicated voltage gains) = 15V with out­put terminal driven to either supply rail.
FIGURE 1. BLOCK DIAGRAM OF THE CA3130 SERIES
22.5
GATE VOLTAGE (TERMINALS 4 AND 8) (V)
OUTPUT VOLTAGE (TERMINALS 4 AND 8) (V)
17.5 2012.5 15107.52.5 50
2.5
7.5
5
10
15
12.5
17.5
0
SUPPLY VOLTAGE: V+ = 15, V- = 0V T
A
= 25oC
LOAD RESISTANCE = 5k
500
1k
2k
FIGURE 2. VOL T A GE TRANSFER CHARA CTERISTICS OF
CMOS OUTPUT STAGE
CA3130, CA3130A
Page 6
3-69
metal can package also contributes an increment of leakage current, there are useful compensating factors. Because the gate-protection network functions as if it is connected to Ter­minal 4 potential, and the Metal Can case of the CA3130 is also internally tied to Ter minal 4, input Terminal 3 is essen­tially “guarded” from spurious leakage currents.
Offset Nulling
Offset-voltage nulling is usually accomplished with a 100,000 potentiometer connected across Terminals 1 and 5 and with the potentiometer slider arm connected to Terminal 4. A fine offset-null adjustment usually can be effected with the slider arm positioned in the mid-point of the potentiometer’s total range.
Input-Current Variation with Temperature
The input current of the CA3130 Series circuits is typically 5pA at 25
o
C. The major portion of this input current is due to leakage current through the gate-protective diodes in the input circuit. As with any semiconductor-junction device, including op amps with a junction-FET input stage, the leakage current approximately doubles for every 10
o
C increase in tempera­ture. Figure 4 provides data on the typical variation of input bias current as a function of temperature in the CA3130.
In applications requiring the lowest practical input current and incremental increases in current because of “warm-up” effects, it is suggested that an appropriate heat sink be used with the CA3130. In addition, when “sinking” or “sourcing” significant output current the chip temperature increases, causing an increase in the input current. In such cases, heat­sinking can also very markedly reduce and stabilize input current variations.
Input Offset Voltage (V
IO
) Variation with DC Bias and
Device Operating Life
It is well known that the characteristics of a MOSFET device can change slightly when a DC gate-source bias potential is applied to the device for extended time periods. The magni­tude of the change is increased at high temperatures. Users of the CA3130 should be alert to the possible impacts of this effect if the application of the device involves extended oper­ation at high temperatures with a significant differential DC bias voltage applied across Terminals 2 and 3. Figure 5 shows typical data pertinent to shifts in offset voltage encountered with CA3130 devices (metal can package) dur­ing life testing. 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. The 2V
DC
differential voltage example represents conditions when the amplifier output stage is “toggled”, e.g., as in comparator applications.
o
10
7.5
5
2.5
0
-101234567 INPUT CURRENT (pA)
INPUT VOLTAGE (V)
TA = 25oC
3
2
7
4
8
6
PA
V
IN
CA3130
15V
TO 5V
0V
TO
-10V
V+
V-
FIGURE 3. INPUT CURRENT vs COMMON-MODE VOLTAGE
VS = ±7.5V
4000
1000
100
10
1
-80 -60 -40 -20 0 20 40 60 80 100 120 140
INPUT CURRENT (pA)
TEMPERATURE (oC)
FIGURE 4. INPUT CURRENT vs TEMPERATURE
FIGURE 5. TYPICAL INCREMENTAL OFFSET-VOLTAGE
SHIFT vs OPERATING LIFE
TA = 125oC FOR TO-5 PACKAGES
7
6
5
4
3
2
1
0 500 1000 1500 2000 2500 3000 3500 4000
OFFSET VOLTAGE SHIFT (mV)
TIME (HOURS)
DIFFERENTIAL DC VOLTAGE (ACROSS TERMINALS 2 AND 3) = 0V OUTPUT VOLTAGE = V+ / 2
DIFFERENTIAL DC VOLTAGE (ACROSS TERMINALS 2 AND 3) = 2V OUTPUT STAGE TOGGLED
0
CA3130, CA3130A
Page 7
3-70
Power-Supply Considerations
Because the CA3130 is very useful in single-supply applica­tions, it is pertinent to review some considerations relating to power-supply current consumption under both single-and dual-supply service. Figures 6A and 6B show the CA3130 connected for both dual-and single-supply operation.
Dual-supply Operation: When the output voltage at Terminal 6 is 0V, the currents supplied by the two power supplies are equal. When the gate terminals of Q
8
and Q12 are driven increasingly positive with respect to ground, current flow through Q
12
(from the negative supply) to the load is
increased and current flow through Q
8
(from the positive supply) decreases correspondingly. When the gate terminals of Q
8
and Q12 are driven increasingly negative with respect
to ground, current flow through Q
8
is increased and current
flow through Q
12
is decreased accordingly.
Single-supply Operation: Initially, let it be assumed that the value of R
L
is very high (or disconnected), and that the input­terminal bias (T erminals 2 and 3) is such that the output termi­nal (No. 6) voltage is at V+/2, i.e ., the v oltage drops across Q
8
and Q12 are of equal magnitude. Figure 20 shows typical qui­escent supply-current vs supply-voltage for the CA3130 oper­ated under these conditions. Since the output stage is operating as a Class A amplifier, the supply-current will remain constant under dynamic operating conditions as long as the transistors are operated in the linear portion of their voltage-transfer characteristics (see Figure 2). If either Q
8
or
Q
12
are swung out of their linear regions toward cut-off (a non-linear region), there will be a corresponding reduction in supply-current. In the extreme case, e.g., with Terminal 8
swung down to ground potential (or tied to ground), NMOS transistor Q
12
is completely cut off and the supply-current to
series-connected transistors Q
8
, Q12 goes essentially to zero. The two preceding stages in the CA3130, however, continue to draw modest supply-current (see the lower curve in Figure
20) even though the output stage is strobed off. Figure 6A shows a dual-supply arrangement for the output stage that can also be strobed off, assuming R
L
= by pulling the poten-
tial of Terminal 8 down to that of Terminal 4. Let it now be assumed that a load-resistance of nominal
value (e.g., 2k) is connected between Terminal 6 and ground in the circuit of Figure 6B. Let it be assumed again that the input-terminal bias (Ter minals 2 and 3) is such that the output terminal (No. 6) voltage is at V+/2. Since PMOS transistor Q
8
must now supply quiescent current to both R
L
and transistor Q12, it should be apparent that under these conditions the supply-current must increase as an inverse function of the R
L
magnitude. Figure 22 shows the voltage-
drop across PMOS transistor Q
8
as a function of load cur­rent at several supply voltages. Figure 2 shows the voltage­transfer characteristics of the output stage for several values of load resistance.
Wideband Noise
From the standpoint of low-noise performance consider­ations, the use of the CA3130 is most advantageous in appli­cations where in the source resistance of the input signal is on the order of 1M or more. In this case, the total input­referred noise voltage is typically only 23µV when the test­circuit amplifier of Figure 7 is operated at a total supply volt­age of 15V. This value of total input-referred noise remains essentially constant, even though the value of source resis­tance is raised by an order of magnitude. This characteristic is due to the fact that reactance of the input capacitance becomes a significant factor in shunting the source resis­tance. It should be noted, however, that for values of source resistance very much greater than 1M, the total noise volt­age generated can be dominated by the thermal noise con­tributions of both the feedback and source resistors.
FIGURE 6A. DUAL POWER SUPPLY OPERATION
FIGURE 6B. SINGLE POWER SUPPLY OPERATION
FIGURE 6. CA3130 OUTPUT STA GE IN DU AL AND SINGLE
POWER SUPPLY OPERATION
3
2
8
4
7
6
R
L
Q
8
Q
12
CA3130
+
-
V+
V-
3
2
8
4
7
6
R
L
Q
8
Q
12
CA3130
+
-
V+
3
2
1
8
4
7
6
+
-
R
s
1M
47pF -7.5V
0.01 µF
+7.5V
0.01µF
NOISE
VOLTAGE
OUTPUT
30.1k
1k
BW (-3dB) = 200kHz TOTAL NOISE VOLTAGE (REFERRED TO INPUT) = 23µV (TYP)
FIGURE 7. TEST-CIRCUIT AMPLIFIER (30-dB GAIN) USED
FOR WIDEBAND NOISE MEASUREMENTS
CA3130, CA3130A
Page 8
3-71
Typical Applications
Voltage Followers
Operational amplifiers with very high input resistances, like the CA3130, are particularly suited to service as voltage followers. Figure 8 sho ws the circuit of a classical v oltage fol­lower, together with pertinent waveforms using the CA3130 in a split-supply configuration.
A voltage follow er, operated from a single supply, is shown in Figure 9, together with related waveforms. This follower cir­cuit is linear over a wide dynamic range, as illustrated by the reproduction of the output waveform in Figure 9A with input­signal ramping. The wavefor ms in Figure 9B show that the follower does not lose its input-to-output phase-sense, even though the input is being swung 7.5V below ground poten­tial. This unique characteristic is an important attribute in both operational amplifier and comparator applications. Fig­ure 9B also shows the manner in which the CMOS output stage permits the output signal to swing down to the nega­tive supply-rail potential (i.e., ground in the case shown). The digital-to-analog converter (DAC) circuit, described later, illustrates the practical use of the CA3130 in a single-supply voltage-follower application.
9-Bit CMOS DAC
A typical circuit of a 9-bit Digital-to-Analog Converter (DAC) is shown in Figure 10. This system combines the concepts of multiple-switch CMOS lCs, a low-cost ladder network of dis­crete metal-oxide-film resistors, a CA3130 op amp con­nected as a follower, and an inexpensive monolithic regulator in a simple single power-supply arrangement. An additional feature of the DAC is that it is readily interfaced with CMOS input logic, e.g., 10V logic levels are used in the circuit of Figure 10.
The circuit uses an R/2R voltage-ladder network, with the output potential obtained directly by terminating the ladder arms at either the positive or the negative power-supply ter­minal. Each CD4007A contains three “inverters”, each “inverter” functioning as a single-pole double-throw switch to terminate an arm of the R/2R network at either the positive or negative power-supply terminal. The resistor ladder is an assembly of 1% tolerance metal-oxide film resistors. The five arms requiring the highest accuracy are assembled with series and parallel combinations of 806,000 resistors from the same manufacturing lot.
A single 15V supply provides a positive bus for the CA3130 follower amplifier and feeds the CA3085 voltage regulator. A “scale-adjust” function is provided by the regulator output control, set to a nominal 10V level in this system. The line­voltage regulation (approximately 0.2%) permits a 9-bit accuracy to be maintained with variations of several volts in the supply. The flexibility afforded by the CMOS building blocks simplifies the design of DAC systems tailored to par­ticular needs.
Single-Supply, Absolute-Value, Ideal Full-Wave Rectifier
The absolute-value circuit using the CA3130 is shown in Figure 11. 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 CA3130 functions as a normal inverting amplifier with a gain equal to -R
2/R1
. When the equality of the two equations shown in Figure 11 is satisfied, the full-wave output is symmetrical.
Peak Detectors
Peak-detector circuits are easily implemented with the CA3130, as illustrated in Figure 12 for both the peak-positive and the peak-negative circuit. It should be noted that with large-signal inputs, the bandwidth of the peak-negative cir­cuit is much less than that of the peak-positive circuit. The second stage of the CA3130 limits the bandwidth in this case. Negative-going output-signal excursion requires a pos­itive-going signal excursion at the collector of transistor Q
11
, which is loaded by the intrinsic capacitance of the associ­ated circuitry in this mode. On the other hand, during a neg­ative-going signal excursion at the collector of Q
11
, the transistor functions in an active “pull-down” mode so that the intrinsic capacitance can be discharged more expeditiously.
CA3130, CA3130A
Page 9
3-72
3
2
1
8
4
7
6
+
-
10k
C
C
= 56pF
-7.5V
0.01µF
+7.5V
0.01µF
2k
2k
BW (-3dB) = 4MHz
SR = 10V/µs
25pF
0.1µF
Top Trace: Output
Center Trace: Input
FIGURE 8A. SMALL-SIGNAL RESPONSE (50mV/DIV.,
200ns/DIV.)
Top Trace: Output Signal; 2V/Div., 5µs/Div.
Center Trace: Difference Signa; 5mV/Div., 5µs/Div.
Bottom Trace: Input Signal; 2V/Div., 5µs/Div.
FIGURE 8B. INPUT-OUTPUT DIFFERENCE SIGNAL SHOWING
SETTLING TIME (MEASUREMENT MADE WITH TEKTRONIX 7A13 DIFFERENTIAL AMPLIFIER)
FIGURE 8. SPLIT SUPPLY VOLTAGE FOLLOWER WITH
ASSOCIATED WAVEFORMS
3
2
8
1
4
7
6
+
-
10k
56pF
OFFSET
+15V
0.01µF
2k
0.1µF
5
ADJUST
100k
FIGURE 9A. OUTPUT WAVEFORM WITH INPUT SIGNAL
RAMPING (2V/DIV., 500µs/DIV.)
Top Trace:Output; 5V/Div., 200µs/Div.
Bottom Trace:Input Signal; 5V/Div., 200µs/Div.
FIGURE 9B. OUTPUT WAVEFORM WITH GROUND
REFERENCE SINE-WAVE INPUT
FIGURE 9. SINGLE SUPPLY VOLTAGE FOLLOWER WITH
ASSOCIATED WAVEFORMS. (e.g., FOR USE IN SINGLE-SUPPL Y D/A CONVERTER; SEE FIGURE 9 IN AN6080)
CA3130, CA3130A
Page 10
3-73
FIGURE 10. 9-BIT DAC USING CMOS DIGITAL SWITCHES AND CA3130
FIGURE 11. SINGLE SUPPLY, ABSOLUTE VALUE, IDEAL FULL-WAVE RECTIFIER WITH ASSOCIATED WAVEFORMS
6 3 101036
4
8
36
7
9
4
10
2
3
13
8
12 12
1
58
1313 1 12
8 5
14 11
2
6
5
1
7
7
1
6
8
4
3
2
10V LOGIC INPUTS
+10.010V
LSB
987 654 321
MSB
806K 1%
PARALLELED
RESISTORS
+15V
VOLTAGE FOLLOWER
CA3130
OUTPUT
LOAD
100K
OFFSET
NULL
56pF
2K
0.1µF
REGULATED
VOLTAGE
ADJ
22.1k 1%
1K
3.83k 1%
0.001µF
CA3085
VOLTAGE
REGULATOR
+15V
2µF 25V
+
-
+10.010V
CD4007A
“SWITCHES”
CD4007A
“SWITCHES”
402K1%200K
1%
100K1%806K1%806K
1%
806K1%750K
1%
806K
1%
806K1%806K1%806K
1%
(2)
(4)
(8)
806K 1%
+
-
62
BIT
1 2 3 4 5
6 - 9
REQUIRED
RATIO-MATCH
STANDARD
±0.1% ±0.2% ±0.4% ±0.8% ±1% ABS
NOTE: All resistances are in ohms.
CD4007A
“SWITCHES”
1
5
10K
2
3
4
6
8
1
5
7
R
2
2k
+15V
0.01 µF
1N914
R
3
5.1k
PEAK
ADJUST
2k
100k
OFFSET ADJUST
20pF
CA3130
R
1
4k
+
-
20V
P-P
Input: BW(-3dB) = 230kHz, DC Output (Avg) = 3.2V
1V
P-P
Input: BW(-3dB) = 130kHz, DC Output (Avg) = 160mV
Gain =
R
2
R
1
------ -
= X =
R
3
R1+R2+R
3
------------------------------------- -
R
3=R1
X+X
2
1 - X
------------------


For X = 0.5:
2K
4k
----------- -
=
R
2
R
1
------ -
R
3
= 4k
0.75
0.5
-----------


= 6k
Top Trace: Output Signal; 2V/Div.
Bottom Trace: Input Signal; 10V/Div.
Time base on both traces: 0.2ms/Div.
0V
0V
CA3130, CA3130A
Page 11
3-74
FIGURE 12A. PEAK POSITIVE DETECTOR CIRCUIT FIGURE 12B. PEAK NEGATIVE DETECTOR CIRCUIT
FIGURE 12. PEAK-DETECTOR CIRCUITS
FIGURE 13. VOLTAGE REGULATOR CIRCUIT (0V TO 13V AT 40mA)
3
2
6
4
7
CA3130
+7.5V
0.01µF
+DC
OUTPUT
5µF
+
-
100
k
1N914
0.01µF
-7.5V
2k
10k
+
-
6V
P-P
INPUT;
BW (-3dB) = 1.3MHz
0.3V
P-P
INPUT;
BW (-3dB) = 240kHz
3
2
6
4
7
CA3130
+7.5V
0.01µF
-DC
OUTPUT
5µF
+
-
100
k
1N914
0.01µF
-7.5V
2k
10k
+
-
6V
P-P
INPUT;
BW (-3dB) = 360kHz
0.3V
P-P
INPUT;
BW (-3dB) = 320kHz
6
3
2
1
8
7
4
CA3086
CURRENT
LIMIT
ADJ
3
R
2
1k
Q
5
13
14
12
Q
1
Q
2
Q
3
Q
4
10 7 3
4269
11815
390
1k
20k
+
-
5µF 25V
56pF
ERROR AMPLIFIER
CA3130
30k
100k
IC1
0.01
VOLTAGE ADJUST
50k
R
1
14
13
Q
5
12
62k
IC
3
OUTPUT 0 TO 13V
AT
40mA
+
-
0.01µF
+20V
INPUT
2.2k
+
-
25µF
IC
2
CA3086
10
11
1, 2
Q
4
Q
1
8, 7
5
Q
3
Q
2
6
4
REGULATION (NO LOAD TO FULL LOAD): <0.01% INPUT REGULATION: 0.02%/V HUM AND NOISE OUTPUT: <25µV UP TO 100kHz
+
-
+
-
1k
9
µF
3
CA3130, CA3130A
Page 12
3-75
Error-Amplifier in Regulated-Power Supplies
The CA3130 is an ideal choice for error-amplifier service in regulated power supplies since it can function as an error­amplifier when the regulated output voltage is required to approach zero. Figure 13 shows the schematic diagram of a 40mA power supply capable of providing regulated output voltage by continuous adjustment over the range from 0V to 13V. Q
3
and Q4 in lC2 (a CA3086 transistor-array lC) func­tion as zeners to provide supply-voltage for the CA3130 comparator (IC
1
). Q1, Q2, and Q5 in IC2 are configured as a low impedance, temperature-compensated source of adjust­able reference voltage for the error amplifier. Transistors Q
1
,
Q
2
, Q3, and Q4 in lC3 (another CA3086 transistor-array lC) are connected in parallel as the series-pass element. Tran­sistor Q
5
in lC3 functions as a current-limiting device by diverting base drive from the series-pass transistors, in accordance with the adjustment of resistor R
2
.
Figure 14 contains the schematic diagram of a regulated power-supply capable of providing regulated output voltage by continuous adjustment over the range from 0.1V to 50V and currents up to 1A. The error amplifier (lC
1
) and circuitry
associated with lC
2
function as previously described,
although the output of lC
1
is boosted by a discrete transistor
(Q
4
) to provide adequate base drive for the Darlington-con-
nected series-pass transistors Q
1
, Q2. Transistor Q3 func-
tions in the previously described current-limiting circuit.
Multivibrators
The exceptionally high input resistance presented by the CA3130 is an attractive feature for multivibrator circuit design because it permits the use of timing circuits with high R/C ratios. The circuit diagram of a pulse generator (astable multivibrator), with provisions for independent control of the “on” and “off” periods, is shown in Figure 15. Resistors R
1
and R2 are used to bias the CA3130 to the mid-point of the supply-voltage and R
3
is the feedback resistor. The pulse
repetition rate is selected by positioning S
1
to the desired position and the rate remains essentially constant when the resistors which determine “on-period” and “off-period” are adjusted.
Function Generator
Figure 16 contains a schematic diagram of a function genera­tor using the CA3130 in the integrator and threshold detector functions. This circuit generates a triangular or square-wave output that can be swept over a 1,000,000:1 range (0.1Hz to 100kHz) by means of a single control, R
1
. A voltage-control
input is also available for remote sweep-control. The heart of the frequency-determining system is an opera-
tional-transconductance-amplifier (OTA) (see Note 10), lC
1
, operated as a voltage-controlled current-source. The output, I
O
, is a current applied directly to the integrating capacitor, C1,
in the feedback loop of the integrator lC
2
, using a CA3130, to
provide the triangular-wave output. Potentiometer R
2
is used
FIGURE 14. VOLTAGE REGULATOR CIRCUIT (0.1V TO 50V AT 1A)
6
2
3
1
8
7
4
4.3k
1
+
-
43k
100µF
ERROR AMPLIFIER
IC
1
VOLTAGE ADJUST
14
13
100µF
+55V
INPUT
2.2k
+
-
IC
2
CA3086 10, 11
Q
4
Q
1
Q
2
6
REGULATION (NO LOAD TO FULL LOAD): <0.005% INPUT REGULATION: 0.01%/V HUM AND NOISE OUTPUT: <250µV
RMS
UP TO 100kHz
+
-
+
-
CA3130
+
-
+
-
1W
3.3k
1W
5µF
9 8, 7
Q
3
1, 2
3 5
4
1k
62k
Q
5
12
10k
Q
2
Q
1
50k
Q
3
1k
2N3055
2N2102
CURRENT LIMIT ADJUST
2N5294
2N2102
Q
4
1000pF
10k
8.2k
OUTPUT:
0.1 TO 50V AT 1A
CA3130, CA3130A
Page 13
3-76
to adjust the circuit for slope symmetry of positive-going and negative-going signal excursions.
Another CA3130, IC
3
, is used as a controlled switch to set the excursion limits of the triangular output from the integra­tor circuit. Capacitor C
2
is a “peaking adjustment” to opti­mize the high-frequency square-wave performance of the circuit.
Potentiometer R
3
is adjustable to perfect the “amplitude symmetry” of the square-wave output signals. Output from the threshold detector is fed back via resistor R
4
to the input
of lC
1
so as to toggle the current source from plus to minus
in generating the linear triangular wave.
Operation with Output-Stage Power-Booster
The current-sourcing and-sinking capability of the CA3130 output stage is easily supplemented to provide power-boost capability. In the circuit of Figure 17, three CMOS transistor­pairs in a single CA3600E (see Note 12) lC array are shown parallel connected with the output stage in the CA3130. In the Class A mode of CA3600E shown, a typical device con­sumes 20mA of supply current at 15V operation. This arrangement boosts the current-handling capability of the CA3130 output stage by about 2.5X.
The amplifier circuit in Figure 17 employs feedback to estab­lish a closed-loop gain of 48dB. The typical large-signal bandwidth (-3dB) is 50kHz.
NOTE:
9. See file number 619 for technical information.
7
4
6
3
2
R
1
100k
R
2
100k
R
3
100k
ON-PERIOD
ADJUST
1M
2k 2k
OFF-PERIOD
ADJUST
1M
+15V
0.01µF
OUTPUT
2k
0.001µF
0.01µF
0.1µF
1µF
S
1
CA3130
+
-
FIGURE 15. PULSE GENERAT OR (ASTABLE MULTIVIBRAT OR)
WITH PROVISIONS FOR INDEPENDENT CONTR OL OF “ON” AND “OFF” PERIODS
FREQUENCY RANGE:
POSITION OF S
1
0.001µF
0.01µF
0.1µF 1µF
PULSE PERIOD 4µs to 1ms 40µs to 10ms
0.4ms to 100ms 4ms to 1s
NOTE:
10. See file number 475 and AN6668 for technical information.
FIGURE 16. FUNCTION GENERATOR (FREQUENCY CAN BE VARIED 1,000,000/1 WITH A SINGLE CONTROL)
6
3
2
1
4
7
5
6
2
3
4
7
8
1
5
4
6
7
3
2
R
4
270k
+7.5V
VOLTAGE-CONTROLLED
CURRENT SOURCE
IC
1
3k
3k
10M
+7.5V
R
2
100k
SLOPE SYMMETRY ADJUST
VOLTAGE CONTROLLED INPUT
-7.5V
10k
10k
R
1
-7.5V
FREQUENCY ADJUST (100kHz MAX)
-7.5V +7.5V
I
O
IC
2
+7.5V
C
1
100pF
INTEGRATOR
-7.5V
56pF
CA3130
+
-
CA3080A
+
-
39k
3 - 30pF
C
2
ADJUST
HIGH - FREQ.
DETECTOR
THRESHOLD
150k
IC
3
+7.5V
CA3130
+
-
R
3
100k
AMPLITUDE SYMMETRY ADJUST
22k
-7.5V
(NOTE 10)
CA3130, CA3130A
Page 14
3-77
NOTES:
11. Transistors QP1, QP2, QP3 and QN1, QN2, QN3 are parallel connected with Q8 and Q12, respectively, of the CA3130.
12. See file number 619.
FIGURE 17. CMOS TRANSISTOR ARRAY (CA3600E) CONNECTED AS POWER BOOSTER IN THE OUTPUT STAGE OF THE CA3130
8
7
3
2
+15V
2k
CA3130
+
-
4
1036
4 97
6
14
750k
1µF
2 11
13 1
12
58
1µF
1M
0.01µF
510k
500µF
Q
P3
Q
N1
Q
N2
Q
N3
Q
P2
Q
P1
CA3600E
A
V(CL)
= 48dB
LARGE SIGNAL BW (-3 dB) = 50kHz
R
L
= 100
(P
O
= 150mW
AT THD = 10%)
(NOTE 12)
INPUT
Typical Performance Curves
FIGURE 18. OPEN LOOP GAIN vs TEMPERATURE
FIGURE 19. OPEN-LOOP RESPONSE
LOAD RESISTANCE = 2k
150
140
130
120
110
100
90
80
-100 -50 0 50 100
OPEN LOOP VOLTAGE GAIN (dB)
TEMPERATURE (oC)
SUPPLY VOLTAGE: V+ = 15V; V- = 0 T
A
= 25oC
φ OL
3
2
1
1
2
3
4
4
AOL
1 - C
L
= 9pF, CC = 0pF, RL =
2 - CL = 30pF, CC = 15pF, RL = 2k 3 - CL = 30pF, CC = 47pF, RL = 2k 4 - C
L
= 30pF, CC = 150pF, RL = 2k
120
100
80
60
40
20
0
OPEN LOOP VOLTAGE GAIN (dB)
-100
-200
-300
OPEN LOOP PHASE (DEGREES)
10210310410510610710
8
FREQUENCY (Hz)
10
1
CA3130, CA3130A
Page 15
3-78
All Harris Semiconductor products are manufactured, assembled and tested under ISO9000 quality systems certification.
Harris Semiconductor products are sold by description only. Harris Semiconductor reser ves the right to make changes in circuit design 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 Harris is believed to be accurate and reliable. However, no responsibility is assumed by Harris 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 Harris or its subsidiaries.
Sales Office Headquarters
For general information regarding Harris Semiconductor and its products, call 1-800-4-HARRIS
NORTH AMERICA
Harris Semiconductor P. O. Box 883, Mail Stop 53-210 Melbourne, FL 32902 TEL: 1-800-442-7747 (407) 729-4984 FAX: (407) 729-5321
EUROPE
Harris Semiconductor Mercure Center 100, Rue de la Fusee 1130 Brussels, Belgium TEL: (32) 2.724.2111 FAX: (32) 2.724.22.05
ASIA
Harris Semiconductor PTE Ltd. No. 1 Tannery Road Cencon 1, #09-01 Singapore 1334 TEL: (65) 748-4200 FAX: (65) 748-0400
SEMICONDUCTOR
FIGURE 20. QUIESCENT SUPPLY CURRENT vs SUPPLY
VOLTAGE
FIGURE 21. QUIESCENT SUPPLY CURRENT vs SUPPLY
VOLTAGE
FIGURE 22. VOLTAGE ACROSS PMOS OUTPUT TRANSISTOR
(Q
8
) vs LOAD CURRENT
FIGURE 23. VOLTAGE ACROSS NMOS OUTPUT TRANSISTOR
(Q12) vs LOAD CURRENT
Typical Performance Curves
(Continued)
LOAD RESISTANCE =
TA = 25oC V- = 0
OUTPUT VOLTAGE BALANCED = V+/2
OUTPUT VOLTAGE HIGH = V+ OR LOW = V-
17.5
12.5
10
7.5
5
2.5
0
6 8 10 12 14 16 18
TOTAL SUPPLY VOLTAGE (V)
QUIESCENT SUPPLY CURRENT (mA)
4
OUTPUT VOLTAGE = V+/2 V- = 0
14
12
10
8
6
4
2
0246810121416
QUIESCENT SUPPLY CURRENT (mA)
TOTAL SUPPLY VOLTAGE (V)
TA = -55oC
25oC
125oC
0
50
10
1
0.1
0.01
0.001
0.001 0.01 0.1 1.0 10 100 MAGNITUDE OF LOAD CURRENT (mA)
VOLTAGE DROP ACROSS PMOS OUTPUT
STAGE TRANSISTOR (V)
15V
10V
NEGATIVE SUPPLY VOLTAGE = 0V
T
A
= 25oC
POSITIVE SUPPLY VOLTAGE = 5V
NEGATIVE SUPPLY VOLTAGE = 0V TA = 25oC
50
10
1
0.1
0.01
0.001
0.001 0.01 0.1 1 10 100 MAGNITUDE OF LOAD CURRENT (mA)
VOLTAGE DROP ACROSS NMOS OUTPUT
STAGE TRANSISTOR (V)
15V
10V
POSITIVE SUPPLY VOLTAGE = 5V
CA3130, CA3130A
Loading...