945

NTE945
Integrated Circuit
Operational Amp
Description:
The NTE945 is a precision, high input impedance operational amplifier in an 8−Lead Metal Can type
package designed for applications requiring extremely low input current errors. This device uses supergain transistors in a Darlington input stage to get input bias currents that are equal to high−quality
FET amplifiers−even in limited temperature range operation.
Unlike most other internally compensated amplifiers, the MOS compensation capacitor is protected
to prevent catastrophic failure from overvoltage spikes on the supplies.
The low current error of this amplifier makes possible many designs that were previously impractical
with monolithic amplifiers. It will operate from 100mΩ source resistances, introducing less error than
general purpose amplifiers with 10kΩ sources, Integrators with worst case drifts less than 10µV/sec
and analog time delays in excess of one day can also be made using capacitors no larger than 1µF.
Features:
D Guaranteed Bias Currents as Low as 50pA
D Maximum Offset Currents Down to 15pA
D Operates from Supplies of ±3V to ±20V
D Supply Current Only 300µA at ±20V
Absolute Maximum Ratings:
Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±20V
Power Dissipation (Note 1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 500mW
Differential Input Current (Note 2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±10mA
Input Voltage (Note 3) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±15V
Output Short−Circuit Duration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Indefinite
Operating Temperature Range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0° to +70°C
Storage Temperature Range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −65° to +150°C
Lead Temperature (Durin Soldering, 10sec) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +300°C
Note 1. The maximum junction temperature is +70°C. For operating at elevated temperatures, the
NTE945 must be derated based on a thermal resistance of +150°C/W, junction−to−ambient,
or +45°C/W, junction−to−case.
Note 2. The inputs are shunted with back−to−back diodes for overvoltage protection. Therefore, excessive current will flow if a differential input voltage in excess of 1V is applied between the
inputs unless some limiting resistance is used.
Note 3. For supply voltages less than ±15V, the absolute maximum input voltage is equal to the supply
voltage.
Electrical Characteristics: (TA = −0° to +55°C, ±5V ≤ VS ≤ ±20V unless otherwise specified)
Parameter
Test Conditions
Input Offset Voltage
TA = +25°C
Input Offset Current
TA = +25°C
Input Bias Current
TA = +25°C
Min
Typ
Max
Unit
−
−
10
mV
−
−
15
mV
−
−
50
pA
−
−
100
pA
−
−
150
pA
−
−
250
pA
Input Resistance
TA = +25°C
1
−
−
GΩ
Supply Current
TA = +25°C
−
−
0.8
mA
Large Signal Voltage Gain
VS = ±15V, VOUT = ±10V,
RL ≥ 10kΩ
20
−
−
V/mV
15
−
−
V/mV
TA = +25°C
Output Voltage Swing
VS = ±15V, RL = 10kΩ
±13
−
−
V
Input Voltage Range
VS = ±15V
±13
−
−
V
Common Mode Rejection Ratio
80
−
−
dB
Supply Voltage Rejection Ratio
80
−
−
dB
Pin Connection Diagram
(Top View)
Compensation
Output
V (+)
5
4
6
3 Non−Invert Input
7
Balance
V (−)
8
2
1
Balance
Invert Input
.370 (9.39) Dia Max
.335 (8.52) Dia Max
.177 (4.5)
Max
.492
(12.5)
Min
.018 (0.45) Dia Typ
3
2
4
1
45°
8
7
5
6
.032 (0.82)
.200 (5.06)
Dia
Similar pages