Intersil Corporation CA3420A, CA3420 Datasheet
TM
CA3420, CA3420A
Data Sheet April 2000
0.5MHz, Low Supply Voltage, Low Input
Current BiMOS Operational Amplifiers
The CA3420A and CA3420 are integrated circuit operational
amplifiers that combine PMOS transistors and bipolar
transistors on a single monolithic chip. The CA3420A and
CA3420 BiMOS operational amplifiers feature gate
protected PMOS transistors in the input circuit to provide
very high input impedance,very low input currents (less than
1pA). The internal bootstrapping network features a unique
guardbanding techniquefor reducingthedoubling ofleakage
current forevery 10
o
C increase in temperature.TheCA3420
series operates at total supply voltages from 2V to 20V
either single or dual supply.Theseoperationalamplifiersare
internally phase compensated to achieve stable operation in
the unity gain follower configuration. Additionally, they have
access terminals 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 in the input stage results in
common mode input voltage capability down to 0.45V below
the negativesupplyterminal,animportant attributefor single
supply application. The output stage uses a feedback OTA
type amplifier that can swing essentially from rail-to-rail. The
output driving current of 1.5mA (Min) is provided by using
nonlinear current mirrors.
Ordering Information
TEMP.
PART NUMBER
CA3420AT -55 to 125 8 Pin Metal Can T8.C
CA3420E -55 to 125 8 Ld PDIP E8.3
RANGE (oC) PACKAGE
PKG.
NO.
File Number 1320.6
Features
• 2V Supply at 300µA Supply Current
o
• 1pA Input Current (Typ) (Essentially Constant to 85
C)
• Rail-to-Rail Output Swing (Drive ±2mA into 1kΩ Load)
• Pin Compatible with 741 Operational Amplifiers
Applications
• pH Probe Amplifiers
• Picoammeters
• Electrometer (High Z) Instruments
• Portable Equipment
• Inaccessible Field Equipment
• Battery-Dependent Equipment (Medical and Military)
Functional Diagram
X1
-
MOS
BIPOLAR
+
X1
MOS
BIPOLAR
Pinouts
OFFSET NULL
INV.
INPUT
NON-INV.
INPUT
1
2
3
4
V-
CA3420 (PDIP)
TOP VIEW
-
+
1
BUFFER AMPS;
BOOTSTRAPPED
INPUT PROTECTION
NETWORK
8
STROBE
7
V+
6
OUTPUT
5
OFFSET NULL
1-888-INTERSIL or 321-724-7143 | Intersil and Design is a trademark of Intersil Corporation. | Copyright © Intersil Corporation 2000
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
OFFSET NULL
INPUT
NON-INV.
HIGH GAIN
(50K)
CA3420 (METAL CAN)
TOP VIEW
TAB
8
1
INV.
INPUT
-
2
+
3
4
V-
7
5
OTA BUFFER
STROBE
V+
OUTPUT
6
OFFSET NULL
(X2)
CA3420, CA3420A
Absolute Maximum Ratings Thermal Information
Supply Voltage (V+ to V-). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22V
Differential Input Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15V
DC Input Voltage . . . . . . . . . . . . . . . . . . . . . . (V+ + 8V) to (V- -0.5V)
Input Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1mA
Output Short Circuit Duration (Note 1). . . . . . . . . . . . . . . . Indefinite
Operating Conditions
Temperature Range. . . . . . . . . . . . . . . . . . . . . . . . . -55oC to 125oC
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.
Thermal Resistance (Typical, Note 2) θJA (oC/W) θJC (oC/W)
PDIP Package . . . . . . . . . . . . . . . . . . . 105 N/A
Metal Can Package . . . . . . . . . . . . . . . 165 80
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
Electrical Specifications Typical Values Intended Only for Design Guidance, V
PARAMETER SYMBOL TEST CONDITIONS CA3420A CA3420 UNITS
Input Resistance R
Input Capacitance C
Output Resistance R
Equivalent Input Noise Voltage e
Short-Circuit Current Source IOM+ 2.6 2.6 mA
To Opposite Supply Sink IOM- 2.4 2.4 mA
Gain Bandwidth Product f
Slew Rate SR 0.5 0.5 V/µs
Transient Response Rise Time t
Overshoot OS 15 15 %
Current from Terminal 8 To V- I8+2020µA
To V+ I8-22mA
Electrical Specifications For Equipment Design, At V
PARAMETER SYMBOL
Input Offset Voltage |VIO| - 5 10 - 2 5 mV
Input Offset Current (Note 3) |IIO| - 0.01 4 - 0.01 4 pA
Input Current (Note 3) |II| - 1 5 - 0.02 5 pA
Large Signal Voltage Gain A
Common Mode Rejection Ratio CMRR - 560 1800 - 560 1000 µV/V
Common Mode Input Voltage Range V
Power Supply Rejection Ratio PSRR ∆VIO/∆V - 100 1000 - 32 320 µV/V
Max Output Voltage VOM+RL = ∞ 0.90 0.95 - 0.90 0.95 - V
Supply Current I+ - 350 650 - 350 650 µA
Device Dissipation P
Input Offset Voltage Temperature Drift ∆VlO/∆T - 4- - 4-µV/oC
NOTE:
3. Themaximum limit represents thelevels obtainableon high speed automatictestequipment. T ypicalvalues are obtainedunder laboratory conditions.
I
I
O
f = 1kHz RS = 100Ω 62 62 nV/√Hz
N
f = 10kHz 38 38 nV/√Hz
T
RL = 2kΩ, CL = 100pF 0.7 0.7 µs
R
= ±1V, TA = 25oC, Unless Otherwise Specified
SUPPLY
TEST
CONDITIONS
RL = 10kΩ 10 100 - 20 100 - kV/V
OL
+ 0.2 0.5 - 0.2 0.5 - V
lCR
V
- - -1.3 - -1 -1.3 - V
lCR
VOM- -0.85 -0.91 - -0.85 -0.91 - V
D
CA3420 CA3420A
80 100 - 86 100 - dB
55 65 - 60 65 - dB
60 80 - 70 90 - dB
- 0.7 1.1 - 0.7 1.1 mW
= ±10V, TA = 25oC
SUPPLY
150 150 TΩ
4.9 4.9 pF
300 300 Ω
0.5 0.5 MHz
UNITSMIN TYP MAX MIN TYP MAX
2
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