The LM101A series are general purpose operational amplifiers which feature improved performance over industry standards like the LM709. Advanced processing techniques
make possible an order of magnitude reduction in input currents, and a redesign of the biasing circuitry reduces the
temperature drift of input current.Improvedspecifications include:
Offset voltage 3 mV maximum over temperature
•
(LM101A/LM201A)
Input current 100 nA maximum over temperature
•
(LM101A/LM201A)
Offset current 20 nA maximum over temperature
•
(LM101A/LM201A)
Guaranteed drift characteristics
•
Offsets guaranteed over entire common mode and sup-
•
ply voltage ranges
Slew rate of 10V/µs as a summing amplifier
•
This amplifier offers many features which make its application nearly foolproof: overload protection on the input
LM101A/LM201A/LM301A Operational Amplifiers
September 1999
and output, no latch-up when the common mode range is
exceeded, and freedom from oscillations and compensation with a single 30 pF capacitor. It has advantages over
internally compensated amplifiers in that the frequency
compensation can be tailored to the particular application. For example, in low frequency circuits it can be overcompensated for increased stability margin. Or the compensation can be optimized to give more than a factor of
ten improvement in high frequency performance for most
applications.
In addition, the device provides better accuracy and lower
noise in high impedance circuitry. The low input currents
also make it particularly well suited for long interval integrators or timers, sample and hold circuits and low frequency waveform generators. Further, replacing circuits
where matched transistor pairs buffer the inputs of conventional IC op amps, it can give lower offset voltage and
a drift at a lower cost.
The LM101A is guaranteed over a temperature range of
−55˚C to +125˚C, the LM201A from −25˚C to +85˚C, and
the LM301A from 0˚C to +70˚C.
If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
LM101A/LM201ALM301A
Supply Voltage
Differential Input Voltage
Input Voltage (Note 3)
±
22V
±
30V
±
15V
Output Short Circuit Duration (Note 4)ContinuousContinuous
Operating Ambient Temp. Range−55˚C to +125˚C (LM101A)0˚C to +70˚C
Input Offset VoltageR
Average Temperature Coefficient R
=
25˚C, R
A
=
25˚C1.5103.050nA
A
=
25˚C307570250nA
A
=
25˚C1.54.00.52.0MΩ
A
=
25˚CV
A
=
25˚C, V
A
V
OUT
≤ 50 kΩ3.010mV
S
≤ 50 kΩ3.0156.030µV/˚C
S
of Input Offset Voltage
Input Offset Current2070nA
Average Temperature Coefficient 25˚C ≤ T
of Input Offset CurrentT
≤ TA≤ 25˚C0.020.20.020.6nA/˚C
MIN
Input Bias Current0.10.3µA
Supply CurrentT
=
T
A
≤ 50 kΩ0.72.02.07.5mV
S
=
±
20V1.83.0mA
S
=
±
V
15V1.83.0mA
=
S
=
±
10V, RL≥ 2kΩ
≤ T
A
MAX
=
MAX,VS
S
±
15V5016025160V/mV
0.010.10.010.3nA/˚C
±
20V1.22.5mA
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Electrical Characteristics (Note 5) (Continued)
=
T
T
A
J
ParameterConditionsLM101A/LM201ALM301AUnits
MinTypMax MinTypMax
=
±
Large Signal Voltage GainV
Output Voltage SwingV
Input Voltage RangeV
Common-Mode Rejection RatioR
Supply Voltage Rejection RatioR
Note 2: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur.Operating ratings indicate for which the device is functional, but
do no guarantee specific performance limits. Electrical Characteristics state DC and AC electrical specifications under particular test conditions which guarantee specific limits. This assumes that the device is within the Operating Ratings. Specifications are not guaranteed for parameters where no limit is given, however,thetypical
value is a good indication of device performance.
Note 3: For supply voltages less than
Note 4: Continuous short circuit is allowed for case temperatures to 125˚C and ambient temperatures to 75˚C for LM101A/LM201A, and 70˚C and 55˚C respectively
for LM301A.
Note 5: Unless otherwise specified, these specifications apply for C1=30 pF,
Note 6: Refer to RETS101AX for LM101A military specifications and RETS101X for LM101 military specifications.
Note 7: Human body model, 100 pF discharged through 1.5 kΩ.
±
15V, V
S
R
≥ 2k
L
=
±
15VR
S
=
±
20V
S
=
±
V
15V+15,
S
≤ 50 kΩ80967090dB
S
≤ 50 kΩ80967096dB
S
15V, the absolute maximum input voltage is equal to the supply voltage.
=
±
10V2515V/mV
OUT
=
10 kΩ
L
=
R
2kΩ
L
±
5V ≤ VS≤±20V and −55˚C ≤ TA≤ +125˚C (LM101A),±5V ≤ VS≤±20V and −25˚C
Typical Performance Characteristics for Various Compensation Circuits
(Note 9)
CS=30pF
Single Pole Compensation
DS007752-8
Feedforward Compensation
CS=30pF
C2=10C1
DS007752-16
Two Pole Compensation
DS007752-12
=
f
3 MHz
o
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Typical Performance Characteristics for Various Compensation Circuits
(Note 9) (Continued)
Open Loop Frequency
Response
Large Signal Frequency
Response
Voltage Follower Pulse
Response
DS007752-9
DS007752-10
Open Loop Frequency
Response
Large Signal Frequency
Response
Voltage Follower Pulse
Response
DS007752-13
DS007752-14
Open Loop Frequency
Response
DS007752-17
Large Signal Frequency
Response
DS007752-18
Inverter Pulse Response
DS007752-11
DS007752-15
DS007752-19
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Typical Applications (Note 9)
Variable Capacitance Multiplier
Fast Inverting Amplifier
with High Input Impedance
DS007752-20
L≅R1 R2 C1
=
R2
R
S
=
R1
R
P
Simulated Inductor
DS007752-21
Inverting Amplifier
with Balancing Circuit
DS007752-22
Sine Wave Oscillator
=
f
10 kHz
o
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†
May be zero or equal to parallel combination of R1 and R2 for minimum
offset.
DS007752-24
DS007752-23
Typical Applications (Note 9) (Continued)
Integrator with Bias Current Compensation
*
Adjust for zero integrator drift. Current drift typically 0.1 nA/˚C over −55˚C to +125˚C temperature range.
DS007752-25
Application Hints (Note 9)
Protecting Against Gross
Fault Conditions
*
Protects input
†
Protects output
‡
Protects output — not needed when R4 is used.
DS007752-26
Isolating Large Capacitive Loads
Compensating for Stray Input Capacitances
or Large Feedback Resistor
DS007752-27
Although the LM101A is designed for trouble free operation,
experience has indicated that it is wise to observe certain
precautions given below to protect the devices from abnormal operating conditions. It might be pointed out that the ad-
DS007752-28
vice given here is applicable to practically any IC op amp, although the exact reason why may differ with different
devices.
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Application Hints (Note 9) (Continued)
When driving either input from a low-impedance source, a
limiting resistor should be placed in series with the input lead
to limit the peak instantaneous output current of the source
to something less than 100 mA. This is especially important
when the inputs go outside a piece of equipment where they
could accidentally be connected to high voltage sources.
Large capacitors on the input (greater than 0.1 µF) should be
treated as a low source impedance and isolated with a resistor. Low impedance sources do not cause a problem unless
their output voltage exceeds the supply voltage. However,
the supplies go to zero when they are turned off, so the isolation is usually needed.
The output circuitry is protected against damage from shorts
to ground. However, when the amplifier output is connected
to a test point, it should be isolated by a limiting resistor, as
test points frequently get shorted to bad places. Further,
when the amplifer drives a load external to the equipment, it
is also advisable to use some sort of limiting resistance to
preclude mishaps.
Precautions should be taken to insure that the power suppliesfortheintegratedcircuitneverbecome
reversed—even under transient conditions. With reverse
voltages greater than 1V, the IC will conduct excessive cur-
Typical Applications (Note 9)
rent, fusing internal aluminum interconnects. If there is a
possibility of this happening, clamp diodes with a high peak
current rating should be installed on the supply lines. Reversal of the voltage between V
+
and V−will always cause a
problem, although reversals with respect to ground may also
give difficulties in many circuits.
The minimum values given for the frequency compensation
capacitor are stable only for source resistances less than
10 kΩ, stray capacitances on the summing junction less than
5 pF and capacitive loads smaller than 100 pF. If any of
these conditions are not met, it becomes necessary to overcompensate the amplifier with a larger compensation capacitor.Alternately, lead capacitors can be used in the feedback
network to negate the effect of stray capacitance and large
feedback resistors or an RC network can be added to isolate
capacitive loads.
Although the LM101A is relatively unaffected by supply bypassing, this cannot be ignored altogether. Generally it is
necessary to bypass the supplies to ground at least once on
every circuit card, and more bypass points may be required
if more than five amplifiers are used. When feed-forward
compensation is employed, however, it is advisable to bypass the supply leads of each amplifier with low inductance
capacitors because of the higher frequencies involved.
Standard Compensation and
Offset Balancing Circuit
DS007752-29
Power Bandwidth: 15 kHz
Slew Rate: 1V/µs
Fast Voltage Follower
DS007752-31
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Typical Applications (Note 9) (Continued)
Fast Summing Amplifier
Power Bandwidth: 250 kHz
Small Signal Bandwiidth: 3.5 MHz
Slew Rate: 10V/µs
DS007752-30
R3=R4+R5
R1=R2
Fast AC/DC Converter (Note 8)
Bilateral Current Source
DS007752-32
Note 8: Feedforward compensation can be used to make a fast full wave rectifier without a filter.
DS007752-33
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Typical Applications (Note 9) (Continued)
Instrumentation Amplifier
R1=R4; R2=R3
*
,†Matching determines CMRR.
Integrator with Bias Current Compensation
*
Adjust for zero integrator drift. Current drift typically 0.1 nA/˚C over 0˚C to
+70˚C temperature range.
DS007752-35
DS007752-34
Voltage Comparator for Driving RTL Logic or High
Current Driver
DS007752-37
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Typical Applications (Note 9) (Continued)
Low Frequency Square Wave Generator
DS007752-36
Low Drift Sample and Hold
*
Polycarbonate-dielectric capacitor
Voltage Comparator for Driving
DTL or TTL Integrated Circuits
DS007752-39
DS007752-38
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Schematic (Note 9)
Note 9: Pin connections shown are for 8-pin packages.
NATIONAL’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT
DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT AND GENERAL
COUNSEL OF NATIONAL SEMICONDUCTOR CORPORATION. As used herein:
1. Life support devices or systems are devices or
systems which, (a) are intended for surgical implant
into the body, or (b) support or sustain life, and
whose failure to perform when properly used in
accordance with instructions for use provided in the
2. A critical component is any component of a life
support device or system whose failure to perform
can be reasonably expected to cause the failure of
the life support device or system, or to affect its
safety or effectiveness.
labeling, can be reasonably expected to result in a
significant injury to the user.
National does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and National reserves the right at any time without notice to change said circuitry and specifications.