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Details, datasheet, quote on part number:LM108AH/883
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| Part: | LM108AH/883 |
| Category: | Analog & Mixed-Signal Processing => Amplifiers => Operational Amplifiers => Precision |
| Description: | LM108A - Operational Amplifiers, Package: TO-5, Pin Nb=8 |
| Company: | National Semiconductor Corporation |
| Datasheet: | Download LM108AH/883 datasheet File size : 162 kB |
| Request For quote: | Find where to buy LM108AH/883
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Datasheet text preview:
LM108A LM208A LM308A Operational Amplifiers
May 1989
LM108A LM208A LM308A Operational Amplifiers
General Description
The LM108 LM108A series are precision operational amplifiers having specifications about a factor of ten better than FET amplifiers over their operating temperature range In addition to low input currents these devices have extremely low offset voltage making it possible to eliminate offset adjustments in most cases and obtain performance apT proaching chopper stabilized amplifiers he devices operate with supply voltages from g 2V to g 18V and have sufficient supply rejection to use unregulated supplies Although the circuit is interchangeable with and uses the same compensation as the LM101A an alternate compensation scheme can be used to make it particularly insensitive to power supply noise and to make supply byT pass capacitors unnecessary he low current error of the LM108A series makes possible many designs that are not practical with conventional amplifiers In fact it operates from 10 MX source resistances ntroducing less error than devices like the 709 with 10 kX sources Integrators with drifts less than 500 mV sec and analog time delays in excess of one hour can be made usT ing capacitors no larger than 1 mF he LM208A is identical to the LM108A except that the LM208A has its performance guaranteed over a b25 C to a T 85 C temperature range instead of b55 C to a 125 C he LM308A devices have slightly-relaxed specifications and performances over a 0 C to a 70 C temperature range F
eatures
Y Y Y Y Y
i
Offset voltage guaranteed less than 0 5 mV Maximum input bias current of 3 0 nA over temperature Offset current less than 400 pA over temperature Supply current of only 300 mA even in saturation Guaranteed 5 mV C drift
Compensation Circuits
Standard Compensation Circuit lternate Frequency Compensation
Cf t
R1 CO R1 a R2
CO e 30 pF
TL H 7759 1
Improves rejection of power supply noise by a factor of ten B
T
L H 7759 2
Bandwidth and slew rate are proportional to 1 Cf
andwidth and slew rate are proportional to 1 Cs A
Feedforward Compensation
TL H 7759 3
C1995 National Semiconductor Corporation
TL H 7759
RRD-B30M115 Printed in U S A
LM108A LM208A Absolute Maximum Ratings
p If Military Aerospace specified devices are required lease contact the National Semiconductor Sales ( Office Distributors for availability and specifications Note 5) Supply Voltage Power Dissipation (Note 1) Differential Input Current (Note 2) Input Voltage (Note 3) Output Short-Circuit Duration
g 20V
b 65 C to a 150 C Storage Temperature Range Lead Temperature (Soldering 10 sec ) (DIP) 260 C
500 mW
g 10 mA g 15V
Soldering Information Dual-In-Line Package Soldering (10 sec ) Small Outline Package Vapor Phase (60 sec ) Infrared (15 sec )
260 C 215 C 220 C
Continuous
Operating Free Air Temperature Range b 55 C to a 125 C LM108A b 25 C to a 85 C LM208A
See An-450 ``Surface Mounting Methods and Their Effect on Product Reliability'' for other methods of soldering surE face mount devices SD Tolerance (Note 6) 2000V
Electrical Characteristics (Note 4)
Parameter Input Offset Voltage Input Offset Current Input Bias Current Input Resistance Supply Current Large Signal Voltage Gain Input Offset Voltage Average Temperature Coefficient of Input Offset Voltage Input Offset Current Average Temperature Coefficient of Input Offset Current Input Bias Current Supply Current Large Signal Voltage Gain Output Voltage Swing Input Voltage Range Common Mode Rejection Ratio Supply Voltage Rejection Ratio TA e 125 C VS e g 15V VOUT e g 10V RL t 10 kX VS e g 15V RL e 10 kX VS e g 15V 4 0
g 14
Conditions TA e 25 C TA e 25
Min
Typ 03 0 05 08
Max 05 02 20
Units mV nA nA MX
C
30
TA e 25 C TA e 25 C TA e 25 C TA e 25 C VS e g 15V VOUT e g 10V RL t 10 kX 8 0
70 03 300 10 10 50 04 05 25 30 0 15 04 06
mA V mV mV mV C nA pA C nA mA V mV V V
g 13 g 13 5
96 96
110 110
dB dB
Note 1 The maximum junction temperature of the LM108A is 150 C while that of the LM208A is 100 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 Nackage is 100 C W junction to ambient p ote 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 N 1V is applied between the inputs unless some limiting resistance is used Note 3 For supply voltages less than g 15V the absolute maximum input voltage is equal to the supply voltage ote 4 These specifications apply for g 5V s VS s g 20V and b 55 C s TA s 125 C unless otherwise specified With the LM208A however all temperature N ecifications are limited to b 25 C s TA s 85 C sp Note 5 Refer to RETS108AX for LM108AH and LM108AJ-8 military specifications ote 6 Human body model 1 5 kX in series with 100 pF 2
LM308A Absolute Maximum Ratings
p If Military Aerospace specified devices are required lease contact the National Semiconductor Sales S Office Distributors for availability and specifications upply Voltage Power Dissipation (Note 1) Differential Input Current (Note 2) Input Voltage (Note 3) Output Short-Circuit Duration Operating Temperature Range Storage Temperature Range E H-Package Lead Temperature (Soldering 10 sec )
b 65
g 18V
Lead Temperature (Soldering 10 sec ) (DIP) Soldering Information Dual-In-Line Package Soldering (10 sec ) Small Outline Package Vapor phase (60 sec ) Infrared (15 sec )
260 C
260 C 215 C 220 C
500 mW g 10 mA
g 15V
Continuous 0 C to a 70 C C to a 150 C 300 C
See An-450 ``Surface Mounting Methods and Their Effect on Product Reliability'' for other methods of soldering surE face mount devices SD rating to be determined
lectrical Characteristics (Note 4)
Parameter Input Offset Voltage Input Offset Current Input Bias Current Input Resistance Supply Current Large Signal Voltage Gain Input Offset Voltage Average Temperature Coefficient of Input Offset Voltage Input Offset Current Average Temperature Coefficient of Input Offset Current Input Bias Current Large Signal Voltage Gain Output Voltage Swing Input Voltage Range Common Mode Rejection Ratio Supply Voltage Rejection Ratio VS e g 15V VOUT e g 10V RL t 10 kX VS e g 15V RL e 10 kX VS e g 15V 6 0
g 14
Conditions TA e 25 C TA e 25
Min
Typ 03 02 15
Max 05 1 7
Units mV nA nA MX
C
10
TA e 25 C TA e 25 C TA e 25 C VS e g 15V TA e 25 C VS e g 15V VOUT e g 10V RL t 10 kX VS e g 15V RS e 100X VS e g 15V RS e 100X 8 0
40 03 300 0 73 20 50 15 20 10 10 08
mA V mV mV mV C nA pA C nA V mV V V
g 13 g 14
96 96
110 110
dB dB
Note 1 The maximum junction temperature of the LM308A is 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 N ambient ote 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 N 1V is applied between the inputs unless some limiting resistance is used Note 3 For supply voltages less than g 15V the absolute maximum input voltage is equal to the supply voltage ote 4 These specifications apply for g 5V s VS s g 15V and 0 C s TA s a 70 C unless otherwise specified 3
Typical Applications
Sample and Hold
Teflon polyethylene or polycarbonate dielectric capacitor W
orst case drift less than 2 5 mV sec
TL H 7759 4
High Speed Amplifier with Low Drift and Low Input Current
TL H 7759 5
4
Application Hints
A very low drift amplifier poses some uncommon application and testing problems Many sources of error can cause the apparent circuit drift to be much higher than would be preT dicted hermocouple effects caused by temperature gradient O across dissimilar metals are perhaps the worst offenders nly a few degrees gradient can cause hundreds of microvolts of error The two places this shows up generally are the package-to-printed circuit board interface and temperature gradients across resistors Keeping package leads R short and the two input leads close together helps greatly esistor choice as well as physical placement is important for minimizing thermocouple effects Carbon oxide film and some metal film resistors can cause large thermocouple errors Wirewound resistors of evanohm or manganin are best since they only generate about 2 mV C referenced to copS per Of course keeping the resistor ends at the same temperature is important Generally shielding a low drift stage electrically and thermally will yield good results esistors can cause other errors besides gradient generated voltages If the gain setting resistors do not track with temperature a gain error will result For example a gain of 1000 amplifier with a constant 10 mV input will have a 10V output If the resistors mistrack by 0 5% over the operating temperature range the error at the output is 50 mV Referred to input this is a 50 mV error All of the gain fixing T resistor should be the same material esting low drift amplifiers is also difficult Standard drift testing technique such as heating the device in an oven and having the leads available through a connector thermoprobe or the soldering iron method do not work Thermal C gradients cause much greater errors than the amplifier drift oupling microvolt signal through connectors is especially bad since the temperature difference across the connector can be 50 C or more The device under test along with the gain setting resistor should be isothermal R
chematic Diagram
TL H 7759 6
5
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