LM112
September 1992
LM112/LM212/LM312 Operational Amplifiers
General Description
The LM112 series are micropower operational amplifiers with very low offset-voltage and input-current errorsÐat least a factor of ten better than FET amplifiers over a b55§C to a125§C temperature range. Similar to the LM108 series, that also use supergain transistors, they differ in that they include internal frequency compensation and have provisions for offset adjustment with a single potentiometer.
These amplifiers will operate on supply voltages of g2V to g20V, drawing a quiescent current of only 300 mA. Performance is not appreciably affected over this range of voltages, so operation from unregulated power sources is easily accomplished. They can also be run from a single supply like the 5V used for digital circuits.
The LM112 series are the first IC amplifiers to improve reliability by including overvoltage protection for the MOS compensation capacitor. Without this feature, IC's have been
known to suffer catastrophic failure caused by short-dura- tion overvoltage spikes on the supplies. Unlike other inter- nally-compensated IC amplifiers, it is possible to overcompensate with an external capacitor to increase stability margin.
The LM212 is identical to the LM112, except that the LM212 has its performance guaranteed over a b25§C to a85§C temperature range instead of b55§C to a125§C. The LM312 is guaranteed over a 0§C to a70§C temperature range.
Features
YMaximum input bias current of 3 nA over temperature
YOffset current less than 400 pA over temperature
YLow noise
YGuaranteed drift specifications
Connection Diagram
Metal Can Package
TL/H/7751 ± 4
Top View
Order Number LM112H, LM212H, LM312H or LM112H/883
See NS Package Number H08C
Auxiliary Circuits
Offset Balancing |
Overcompensation for Greater Stability Margin |
TL/H/7751 ± 2 |
TL/H/7751 ± 3 |
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Amplifiers Operational LM112/LM212/LM312
C1995 National Semiconductor Corporation |
TL/H/7751 |
RRD-B30M115/Printed in U. S. A. |
Absolute Maximum Ratings
If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/Distributors for availability and specifications.
(Note 5)
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LM112/LM212 |
LM312 |
Supply Voltage |
g20V |
g18V |
Power Dissipation (Note 1) |
500 mW |
500 mW |
Differential Input Current (Note 2) |
g10 mA |
g10 mA |
Input Voltage (Note 3) |
g15V |
g15V |
Output Short-Circuit Duration |
Continuous |
Continuous |
Operating Temperature Range |
b55§C to a125§C |
0§C to a70§C |
LM112 |
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LM212 |
b25§C to a85§C |
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Storage Temperature Range |
b65§C to a150§C |
b65§C to a150§C |
Lead Temperature (Soldering, 10 sec.) |
300§C |
300§C |
ESD rating to be determined.
Electrical Characteristics (Note 4)
Parameter |
Conditions |
LM112/LM212 |
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LM312 |
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Units |
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Min |
Typ |
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Max |
Min |
Typ |
Max |
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Input Offset Voltage |
TA e 25§C |
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0.7 |
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2.0 |
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2.0 |
7.5 |
mV |
Input Offset Current |
TA e 25§C |
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0.05 |
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0.2 |
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0.2 |
1 |
nA |
Input Bias Current |
TA e 25§C |
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0.8 |
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2.0 |
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1.5 |
7 |
nA |
Input Resistance |
TA e 25§C |
30 |
70 |
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10 |
40 |
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MX |
Supply Current |
TA e 25§C |
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0.3 |
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0.6 |
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0.3 |
0.8 |
mA |
Large Signal Voltage Gain |
TA e 25§C, VS e g15V |
50 |
300 |
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25 |
300 |
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V/mV |
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VOUT e g10V, RL t 10 kX |
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Input Offset Voltage |
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3.0 |
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10 |
mV |
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Average Temperature |
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Coefficient of Input |
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3.0 |
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15 |
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6.0 |
30 |
mV/§C |
Offset Voltage |
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Input Offset Current |
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0.4 |
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1.5 |
nA |
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Average Temperature |
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Coefficient of Input |
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0.5 |
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2.5 |
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2.0 |
10 |
pA/§C |
Offset Current |
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Input Bias Current |
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3.0 |
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10 |
nA |
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Supply Current |
TA e 125§C |
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0.15 |
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0.4 |
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mA |
Large Signal Voltage Gain |
VS e g15V, VOUT e g10V |
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RL t 10 kX |
25 |
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15 |
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V/mV |
Output Voltage Swing |
VS e g15V, RL e 10 kX |
g13 |
g14 |
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g13 |
g14 |
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V |
Input Voltage Range |
VS e g15V |
g13.5 |
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g14 |
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V |
Common-Mode Rejection Ratio |
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85 |
100 |
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80 |
100 |
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dB |
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Supply Voltage Rejection Ratio |
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80 |
96 |
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80 |
96 |
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dB |
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Note 1: The maximum junction temperature of the LM112 is 150§C, LM212 is 100§C and LM312 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.
Note 2: The inputs are shunted with shunt 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 g15V, the absolute maximum input voltage is equal to the supply voltage.
Note 4: These specifications apply for g5V s VS s g20V and b55§C s TA s a125§C (LM112), b25§C s TA s a85§C (LM212), g5V s VS s g15V and 0§ C s TA s a70§C (LM312) unless otherwise noted.
Note 5: Refer to RETS112X for LM112H military specifications.
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