LM108,LM208,LM308
LM108/LM208/LM308 Operational Amplifiers
Literature Number: SNOSBS5A
LM108/LM208/LM308
OBSOLETE
September 22, 2011
Operational Amplifiers
General Description
The LM108 series are precision operational amplifiers having
specifications a factor of ten better than FET amplifiers over
a −55°C to +125°C temperature range.
The devices operate with supply voltages from ±2V to ±20V
and have sufficient supply rejection to use unregulated sup-
plies. Although the circuit is interchangeable with and uses
the same compensation as the LM101A, an alternate com-
pensation scheme can be used to make it particularly insen-
sitive to power supply noise and to make supply bypass
capacitors unnecessary.
The low current error of the LM108 series makes possible
many designs that are not practical with conventional ampli-
fiers. In fact, it operates from 10 MΩ source resistances,
introducing less error than devices like the 709 with 10 kΩ
sources. Integrators with drifts less than 500 μV/sec and ana-
log time delays in excess of one hour can be made using
capacitors no larger than 1 μF.
The LM108 is guaranteed from −55°C to +125°C, the LM208
from −25°C to +85°C, and the LM308 from 0°C to +70°C.
Features
■Maximum input bias current of 3.0 nA over temperature
■Offset current less than 400 pA over temperature
■Supply current of only 300 μA, even in saturation
■Guaranteed drift characteristics
Compensation Circuits
Standard Compensation Circuit
775801
CO = 30 pF
**Bandwidth and slew rate are proportional to 1/Cf
Alternate Frequency Compensation
(Note 1)
775802
**Bandwidth and slew rate are proportional to 1/Cs
Note 1: Improves rejection of power supply noise by a factor of ten.
© 2011 National Semiconductor Corporation 7758 www.national.com
7758 Version 3 Revision 3 Print Date/Time: 2011/09/22 12:58:18
LM108/LM208/LM308 Operational Amplifiers
Feedforward Compensation
775803
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LM108/LM208/LM308
Absolute Maximum Ratings (Note 2)
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
(Note 7)
LM108/LM208 LM308
Supply Voltage ±20V ±18V
Power Dissipation (Note 3) 500 mW 500 mW
Differential Input Current (Note 4) ±10 mA ±10 mA
Input Voltage (Note 5) ±15V ±15V
Output Short-Circuit Duration Continuous Continuous
Operating Temperature Range (LM108) −55°C to +125°C 0°C to +70°C
(LM208) −25°C to + 85°C
Storage Temperature Range −65°C to +150°C −65°C to +150°C
Lead Temperature (Soldering, 10 sec)
DIP 260°C 260°C
H Package Lead Temp
(Soldering 10 seconds) 300°C 300°C
Soldering Information
Dual-In-Line Package
Soldering (10 seconds) 260°C
Small Outline Package
Vapor Phase (60 seconds) 215°C
Infrared (15 seconds) 220°C
See AN-450 “Surface Mounting Methods and Their Effect on Product Reliability” for other
methods of soldering surface mount devices.
ESD Tolerance (Note 8) 2000V
Electrical Characteristics (Note 6)
Parameter Condition LM108/LM208 LM308 Units
Min Typ Max Min Typ Max
Input Offset Voltage TA = 25°C 0.7 2.0 2.0 7.5 mV
Input Offset Current TA = 25°C 0.05 0.2 0.2 1 nA
Input Bias Current TA = 25°C 0.8 2.0 1.5 7 nA
Input Resistance TA = 25°C 30 70 10 40 MΩ
Supply Current TA = 25°C 0.3 0.6 0.3 0.8 mA
Large Signal Voltage TA = 25°C, VS = ±15V 50 300 25 300 V/mV
Gain VOUT = ±10V, RL ≥ 10 kΩ
Input Offset Voltage 3.0 10 mV
Average Temperature
Coefficient of Input 3.0 15 6.0 30 μV/°C
Offset Voltage
Input Offset Current 0.4 1.5 nA
Average Temperature
Coefficient of Input 0.5 2.5 2.0 10 pA/°C
Offset Current
Input Bias Current 3.0 10 nA
Supply Current TA = +125°C 0.15 0.4 mA
Large Signal Voltage VS = ±15V, VOUT = ±10V 25 15 V/mV
Gain RL ≥ 10 kΩ
Output Voltage Swing VS = ±15V, RL = 10 kΩ±13 ±14 ±13 ±14 V
Input Voltage Range VS = ±15V ±13.5 ±14 V
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LM108/LM208/LM308
Parameter Condition LM108/LM208 LM308 Units
Min Typ Max Min Typ Max
Common Mode 85 100 80 100 dB
Rejection Ratio
Supply Voltage 80 96 80 96 dB
Rejection Ratio
Note 2: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for which the device is
functional, but do not guarantee specific performance limits.
Note 3: The maximum junction temperature of the LM108 is 150°C, for the LM208, 100°C and for the LM308, 85°C. For operating at elevated temperatures,
devices in the H08 package must be derated based on a thermal resistance of 160°C/W, junction to ambient, or 20°C/W, junction to case. The thermal resistance
of the dual-in-line package is 100°C/W, junction to ambient.
Note 4: 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 5: For supply voltages less than ±15V, the absolute maximum input voltage is equal to the supply voltage.
Note 6: These specifications apply for ±5V ≤ VS ≤ ±20V and −55°C ≤ TA ≤ +125°C, unless otherwise specified. With the LM208, however, all temperature
specifications are limited to −25°C ≤ TA ≤ 85°C, and for the LM308 they are limited to 0°C ≤ TA ≤ 70°C.
Note 7: Refer to RETS108X for LM108 military specifications and RETs 108AX for LM108A military specifications.
Note 8: Human body model, 1.5 kΩ in series with 100 pF.
Schematic Diagram
775808
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LM108/LM208/LM308
Typical Performance Characteristics LM108/LM208
Input Currents
775818
Offset Error
775819
Drift Error
775820
Input Noise Voltage
775821
Power Supply Rejection
775822
Closed Loop
Output Impedance
775823
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LM108/LM208/LM308
Voltage Gain
775824
Output Swing
775825
Supply Current
775826
Open Loop
Frequency Response
775827
Large Signal
Frequency Response
775828
Voltage Follower
Pulse Response
775829
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LM108/LM208/LM308
Typical Performance Characteristics LM308
Input Currents
775830
Offset Error
775831
Drift Error
775832
Input Noise Voltage
775833
Power Supply Rejection
775834
Closed Loop
Output Impedance
775835
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LM108/LM208/LM308
Voltage Gain
775836
Output Swing
775837
Supply Current
775838
Open Loop
Frequency Response
775839
Large Signal
Frequency Response
775840
Voltage Follower
Pulse Response
775841
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LM108/LM208/LM308
Open Loop
Frequency Response
775839
Large Signal
Frequency Response
775840
Voltage Follower
Pulse Response
775841
Typical Applications
Sample and Hold
775804
†Teflon polyethylene or polycarbonate dielectric capacitor
Worst case drift less than 2.5 mV/sec
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LM108/LM208/LM308
High Speed Amplifier with Low Drift and Low Input Current
775805
Fast Summing Amplifier (Note 9)
775812
*In addition to increasing speed, the LM101A raises high and low frequency gain, increases output drive capability and eliminates thermal feedback.
Note 9: Power Bandwidth: 250 KHz
Small Signal Bandwidth: 3.5 MHz
Slew Rate: 10V/μS
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LM108/LM208/LM308
Connection Diagrams
Metal Can Package
775813
*Package is connected to Pin 4 (V−)
**Unused pin (no internal connection) to allow for input anti-leakage guard
ring on printed circuit board layout.
Order Number LM108H, LM108H/883,
LM308AH or LM308H
See NS Package Number H08C
Dual-In-Line Package
775815
Top View
Order Number LM108J-8/883, LM308M or LM308N
See NS Package Number J08A, M08A or N08E
775816
Top View
Order Number LM108J/883
See NS Package Number J14A
775817
†Also available per JM38510/10104
Order Number LM108W/883
See NS Package Number W10A
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LM108/LM208/LM308
Physical Dimensions inches (millimeters) unless otherwise noted
Ceramic Dual-In-Line Package (J)
Order Number LM108J/883
NS Package Number J08A
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LM108/LM208/LM308
Ceramic Dual-In-Line Package (J)
Order Number LM108/883
NS Package Number J14A
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LM108/LM208/LM308
Metal Can Package (H)
Order Number LM108H, LM108H/883 or LM308H
NS Package Number H08C
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LM108/LM208/LM308
S.O. Package (M)
Order Number LM308M
NS Package Number M08A
Molded Dual-In-Line Package (N)
Order Number LM308N
NS Package Number N08E
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LM108/LM208/LM308
Ceramic Flatpack Package (W)
Order Number LM108AW/883 or LM108W/883
NS Package Number W10A
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LM108/LM208/LM308
Notes
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7758 Version 3 Revision 3 Print Date/Time: 2011/09/22 12:58:18
LM108/LM208/LM308
Notes
LM108/LM208/LM308 Operational Amplifiers
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