CA3420 Intersil Corporation, CA3420 Datasheet - Page 3

• Manufacturer Part Number: CA3420
• Description: 0.5mhz, Low Supply Voltage, Low Input Current Bimos Operational Amplifiers
• Manufacturer: Intersil Corporation

Electrical Specifications
NOTE:
Typical Applications
Picoammeter Circuit
The exceptionally low input current (typically 0.2pA) makes
the CA3420 highly suited for use in a picoammeter circuit.
With only a single 10GΩ resistor, this circuit covers the range
from ±1.5pA. Higher current ranges are possible with suitable
switching techniques and current scaling resistors. Input
transient protection is provided by the 1MΩ resistor in series
with the input. Higher current ranges require that this resistor
be reduced. The 10MΩ resistor connected to pin 2 of the
CA3420 decouples the potentially high input capacitance
often associated with lower current circuits and reduces the
tendency for the circuit to oscillate under these conditions.
High Input Resistance Voltmeter
Advantage is taken of the high input impedance of the CA3420
in a high input resistance DC voltmeter. Only two 1.5V “AA”
type penlite batteries power this exceedingly high-input
resistance (>1,000,000MΩ) DC voltmeter. Full-scale deflection
is ±500mV, ±150mV, and ±15mV. Higher voltage ranges are
easily added with external input voltage attenuator networks.
The meter is placed in series with the gain network, thus
eliminating the meter temperature coefficient error term.
Supply current in the standby position with the meter
undeflected is 300µA. At full-scale deflection this current
rises to 800µA. Carbon-zinc battery life should be in excess
of 1,000 hours.
Input Offset Voltage
Input Offset Current (Note 4)
Input Current (Note 4)
Large Signal Voltage Gain
Common Mode Rejection Ratio
Common Mode Input Voltage Range
Power Supply Rejection Ratio
Max Output Voltage
Supply Current
Device Dissipation
Input Offset Voltage Temperature Drift
4. The maximum limit represents the levels obtainable on high speed automatic test equipment. Typical values are obtained under laboratory conditions.
PARAMETER
3
For Equipment Design, at V
SYMBOL
∆V
PSRR
CMRR
V
V
V
V
|V
A
|I
lCR
|I
OM
OM
P
lCR
I+
SUPPLY
lO
OL
IO
IO
I
D
|
/∆T
|
|
+
+
-
CA3420
-
= ±10V, T
R
∆V
R
L
L
CONDITIONS
IO
= 10kΩ
=
/∆V
∞
TEST
A
1MΩ
22MΩ
= 25°C, Unless Otherwise Specified
FIGURE 2. HIGH INPUT RESISTANCE VOLTMETER
10GΩ
10MΩ
10MΩ
100pF
FIGURE 1. PICOAMMETER CIRCUIT
MIN
-9.7
8.5
-10
9.7
10
10pF
80
70
70
10kΩ
10kΩ
-
-
-
-
-
-
-
-
3
2
2
3
CA3420
+
CA3420
1
+
-
1
-
5
5
-10.3
-9.85
TYP
0.03
0.05
100
100
100
450
9.3
9.9
4
7
32
4
7
80
90
-1.5V
9
5
4
RETURNS
RETURNS
BATTERY
BATTERY
-1.5V
+1.5V
+1.5V
6
6
500-0-500
±500mV
±150mV
500-0-500
MAX
1000
±1.5pA
320
320
±15pA
±15mV
±50pA
±5pA
±50mV
10
14
µA
1.1kΩ
M
5
-
-
-
-
-
-
-
-
-
4
11kΩ
µA
M
1.5kΩ, 1%
430Ω, 1%
150Ω, 1%
1.5kΩ, 1%
430Ω, 1%
150Ω, 1%
October 4, 2005
UNITS
1.5kΩ
µV/°C
1.5kΩ
68Ω
1%
µV/V
µV/V
kV/V
mW
mV
pA
68Ω
1%
1kΩ
pA
dB
dB
dB
µA
1kΩ
FN1320.9
V
V
V
V