LM148/LM248/LM348
Quad 741 Op Amps
LM149
Wide Band Decompensated (A
General Description
The LM148 series is a true quad 741. It consists of four independent, high gain, internally compensated, low power operational amplifiers which have been designed to provide
functional characteristics identical to those of the familiar
741 operational amplifier. In addition the total supply current
for all four amplifiers is comparable to the supply current of a
single 741 type op amp. Other features include input offset
currents and input bias current which are much less than
those of a standard 741. Also, excellent isolation between
amplifiers has been achieved by independently biasing each
amplifier and using layout techniques which minimize thermal coupling. The LM149 series has the same features as
the LM148 plus a gain bandwidth product of 4 MHz at a gain
of 5 or greater.
The LM148 can be used anywhere multiple 741or1558type
amplifiers are being used and in applications where amplifier
matching or high packing density is required.
May 1999
=
V (MIN)
5)
Features
n 741 op amp operating characteristics
n Low supply current drain: 0.6 mA/Amplifier
n Class AB output stage —no crossover distortion
n Pin compatible with the LM124
n Low input offset voltage: 1 mV
n Low input offset current: 4 nA
n Low input bias current: 30 nA
n Gain bandwidth product
LM148 (unity gain): 1.0 MHz
LM149 (A
n High degree of isolation between amplifiers: 120 dB
n Overload protection for inputs and outputs
If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
LM148/LM149LM248LM348
Supply Voltage
Differential Input Voltage
±
22V
±
44V
±
18V
±
36V
±
18V
±
36V
Output Short Circuit Duration (Note 1)ContinuousContinuousContinuous
Power Dissipation (P
Thermal Resistance (θ
Molded DIP (N) P
Cavity DIP (J) P
Maximum Junction Temperature (T
Operating Temperature Range−55˚C ≤ T
d
d
θ
jA
d
θ
JA
at 25˚C) and
), (Note 2)
jA
——750 mW
——100˚C/W
1100 mW800 mW700 mW
110˚C/W110˚C/W110˚C/W
)150˚C110˚C100˚C
jMAX
≤ +125˚C−25˚C ≤ TA≤ +85˚C0˚C ≤ TA≤ +70˚C
A
Storage Temperature Range−65˚C to +150˚C−65˚C to +150˚C−65˚C to +150˚C
Lead Temperature (Soldering, 10 sec.) Ceramic300˚C300˚C300˚C
Lead Temperature (Soldering, 10 sec.) Plastic260˚C
Soldering Information
Dual-In-Line Package
Soldering (10 seconds)260˚C260˚C260˚C
Small Outline Package
Vapor Phase (60 seconds)215˚C215˚C215˚C
Infrared (15 seconds)220˚C220˚C220˚C
See AN-450 “Surface Mounting Methods and Their Effect on Product Reliability” for other methods of soldering surface mount
devices.
ESD tolerance (Note 5)500V500V500V
Electrical Characteristics
(Note 3)
ParameterConditionsLM148/LM149LM248LM348Units
Min Typ Max Min Typ Max Min Typ Max
=
Input Offset VoltageT
Input Offset CurrentT
Input Bias CurrentT
Input ResistanceT
Supply Current All AmplifiersT
Large Signal Voltage GainT
Amplifier to AmplifierT
25˚C, R
A
=
25˚C425450450nA
A
=
25˚C30 10030 20030 200nA
A
=
25˚C0.8 2.50.8 2.50.8 2.5MΩ
A
=
25˚C, V
A
=
25˚C, V
A
V
OUT
=
25˚C, f=1Hzto20kHz
A
Coupling(Input Referred) See Crosstalk−120−120−120dB
Test Circuit
Small Signal BandwidthLM148 Series1.01.01.0MHz
=
T
25˚C
A
Phase MarginLM148 Series (A
=
T
25˚C
A
LM149 Series (A
Slew RateLM148 Series (A
=
T
25˚C
A
LM149 Series (A
Output Short Circuit CurrentT
Input Offset VoltageR
=
25˚C252525mA
A
≤ 10 kΩ6.07.57.5mV
S
Input Offset Current75125100nA
≤ 10 kΩ1.0 5.01.0 6.01.0 6.0mV
S
=
±
15V2.4 3.62.4 4.52.4 4.5mA
S
=
±
15V50 16025 16025 160V/mV
S
=
±
10V, RL≥ 2kΩ
LM149 Series4.04.04.0MHz
=
1)606060degrees
V
=
5)606060degrees
V
=
1)0.50.50.5V/µs
V
=
5)2.02.02.0V/µs
V
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Page 3
Electrical Characteristics (Continued)
(Note 3)
ParameterConditionsLM148/LM149LM248LM348Units
Min Typ Max Min Typ Max Min Typ Max
Input Bias Current325500400nA
Large Signal Voltage GainV
Output Voltage SwingV
Input Voltage RangeV
Common-Mode RejectionR
=
±
15V, V
S
>
R
2kΩ
L
=
±
15V, R
S
=
R
2kΩ
L
=
±
15V
S
≤ 10 kΩ709070907090dB
S
=
±
10V,251515V/mV
OUT
=
10 kΩ
L
±12±
±10±
±
12
13
12
±12±
±10±
±
12
13
12
±12±
±10±
±
12V
13V
12V
Ratio
Supply Voltage RejectionR
Note 1: Any of the amplifier outputs can be shortedto ground indefinitely; however, more than one should not be simultaneously shorted as the maximum junction
temperature will be exceeded.
Note 2: Themaximum power dissipation for these devices must be derated at elevated temperatures and is dicated by T
The maximum available power dissipation at any temperature is P
Note 3: These specifications apply for V
Note 4: Refer to RETS 148X for LM148 military specifications and refer to RETS 149X for LM149 military specifications.
Note 5: Human body model, 1.5 kΩ in series with 100 pF.
≤ 10 kΩ,±5V ≤ VS≤±15V779677967796dB
S
, θjA, and the ambient temperature, TA.
=
=
±
15V and over the absolute maximum operating temperature range (TL≤ TA≤ TH) unless otherwise noted.
S
d
(T
jMAX−TA
)/θjAor the 25˚C P
, whichever is less.
dMAX
jMAX
Cross Talk Test Circuit
DS007786-6
Application Hints
The LM148 series are quad low power 741 op amps. In the
proliferation of quad op amps, these are the first to offer the
convenience of familiar, easy to use operating characteristics of the 741 op amp. In those applications where 741 op
amps have been employed, the LM148 series op amps can
be employed directly with no change in circuit performance.
The LM149 series has the same characteristics as the
LM148 except it has been decompensated to provide a
wider bandwidth. As a result the part requires a minimum
gain of 5.
The package pin-outs are such that the inverting input of
each amplifier is adjacent to its output. In addition, the amplifier outputs are located in the corners of the package which
DS007786-7
=
±
V
15V
S
simplifies PC board layout and minimizes package related
capacitive coupling between amplifiers.
The input characteristics of these amplifiers allow differential
input voltages which can exceed the supply voltages. In addition, if either of the input voltages is within the operating
common-mode range, the phase of the output remains correct. If the negative limit of the operating common-mode
range is exceeded at both inputs, the output voltage will be
positive. For input voltages which greatly exceed the maximum supply voltages, either differentially or common-mode,
resistors should be placed in series with the inputs to limit
the current.
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Page 4
Application Hints (Continued)
Like the LM741, these amplifiers can easily drive a 100 pF
capacitive load throughout the entire dynamic output voltage
and current range. However, if very large capacitive loads
must be driven by a non-inverting unity gain amplifier, a resistor should be placed between the output (and feedback
connection) and the capacitance to reduce the phase shift
resulting from the capacitive loading.
The output current of each amplifier in the package is limited.
Short circuits from an output to either ground or the power
supplies will not destroy the unit. However, if multiple output
shorts occur simultaneously, the time duration should be
short to prevent the unit from being destroyed as a result of
excessive power dissipation in the IC chip.
As with most amplifiers, care should be taken lead dress,
component placement and supply decoupling in order to en-
Typical Performance Characteristics
sure stability.For example, resistors from the output to an input should be placed with the body close to the input to minimize “pickup” and maximize the frequency of the feedback
pole which capacitance from the input to ground creates.
A feedback pole is created when the feedback around any
amplifier is resistive. The parallel resistance and capacitance
from the input of the device (usually the inverting input) to AC
ground set the frequency of the pole. In many instances the
frequency of this pole is much greater than the expected 3
dB frequency of the closed loop gain and consequently there
is negligible effect on stability margin. However, if the feedback pole is less than approximately six times the expected
3 dB frequency a lead capacitor should be placed from the
output to the input of the op amp. The value of the added capacitor should be such that the RC time constant of this capacitor and the resistance it parallels is greater than or equal
to the original feedback pole time constant.
Supply Current
Positive Current Limit
DS007786-23
DS007786-26
Input Bias Current
Negative Current Limit
DS007786-24
DS007786-27
Voltage Swing
DS007786-25
Output Impedance
DS007786-28
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Page 5
Typical Performance Characteristics (Continued)
Common-Mode Rejection
Ratio
Bode Plot LM149
DS007786-29
DS007786-32
Open Loop Frequency
Response
Large Signal Pulse
Response (LM148)
DS007786-30
DS007786-33
Bode Plot LM148
DS007786-31
Large Signal Pulse
Response (LM149)
DS007786-34
Small Signal Pulse
Response (LM148)
DS007786-35
Small Signal Pulse
Response (LM149)
DS007786-36
Undistorted Output
Voltage Swing
DS007786-37
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Page 6
Typical Performance Characteristics (Continued)
Gain Bandwidth
Inverting Large Signal Pulse
Response (LM148)
DS007786-38
DS007786-41
Slew Rate
Input Noise Voltage and
Noise Current
DS007786-39
DS007786-42
Inverting Large Signal Pulse
Response (LM149)
DS007786-40
Positive Common-Mode
Input Voltage Limit
DS007786-43
Negative Common-Mode Input
Voltage Limit
DS007786-5
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Page 7
Typical Applications—LM148
One Decade Low Distortion Sinewave Generator
DS007786-8
=
f
5 kHz, THD ≤ 0.03
MAX
R1=100k pot. C1=0.0047 µF, C2=0.01 µF, C3=0.1 µF, R2=R6=R7=1M,
R3=5.1k, R4=12Ω,R5=240Ω,Q=NS5102, D1=1N914, D2=3.6V avalanche
diode (ex. LM103), V
A simpler version with some distortion degradation at high frequencies can be made by using A1 as a simple inverting amplifier, and by putting back to back
zeners in the feedback loop of A3.
%
=
±
15V
S
Low Cost Instrumentation Amplifier
DS007786-9
=
±
V
15V
S
R=R2, trim R2 to boost CMRR
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Page 8
Typical Applications—LM148 (Continued)
Low Drift Peak Detector with Bias Current Compensation
Adjust R for minimum drift
D3 low leakage diode
D1 added to improve speed
=
±
15V
V
S
DS007786-10
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Page 9
Typical Applications—LM148 (Continued)
Universal State-Variable Filter
Tune Q through R0,
For predictable results: f
Use Band Pass output to tune for Q
Q ≤ 4x10
O
DS007786-11
4
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Page 10
Typical Applications—LM148 (Continued)
A 1 kHz 4 Pole Butterworth
Use general equations, and tune each section separately
Q
The response should have 0 dB peaking
1stSECTION
=
0.541, Q
2ndSECTION
=
1.306
A 3 Amplifier Bi-Quad Notch Filter
=
Ex: f
Better noise performance than the state-space approach.
A 4th Order 1 kHz Elliptic Filter (4 Poles, 4 Zeros)
R1C1=R2C2=t
R'1C'1=R'2C'2=t'
=
f
C
Use the BP outputs to tune Q, Q', tune the 2 sections separately
R1=R2=92.6k, R3=R4=R5=100k, R6=10k, R0=107.8k, R
R'1=R'2=50.9k, R'4=R'5=100k, R'6=10k, R'0=5.78k, R'
1 kHz, f
S
=
2 kHz, f
p
=
0.543, f
=
2.14, Q=0.841, f'
Z
P
=
0.987, f'
L
Lowpass Response
=
4.92, Q'=4.403, normalized to ripple BW
Z
L
=
100k, R'
=
=
100k, R
155.1k,
H
=
248.12k, R'f=100k. All capacitors are 0.001 µF.
H
DS007786-15
DS007786-14
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Page 12
Typical Applications—LM149
Minimum Gain to Insure LM149 Stability
Non-inverting-Integrator Bandpass Filter
DS007786-16
The LM149 as a Unity Gain Inverter
DS007786-17
For stability purposes: R7=R6/4, 10R6=R5, C
f
O(MAX),QMAX
Better Q sensitivity with respect to open loop gain variations than the state variable filter.
R7, C
=
20 kHz, 10
added for compensation
C
=
10C
C
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DS007786-18
Page 13
Typical Applications—LM149 (Continued)
Active Tone Control with Full Output Swing (No Slew Limiting at 20 kHz)
=
±
V
15V, V
S
=
20 kHz, THD ≤ 1
f
MAX
Duplicate the above circuit for stereo
Max Bass Gain≅(R1 + R2)/R1
Max Treble Gain
as shown: f
L
≅
11 kHz, f
f
H
OUT(MAX)
≅
≅
32 Hz, f
HB
≅
=
9.1 V
%
(R1 + 2R7)/R5
≅
320 Hz
LB
1.1 Hz
RMS
,
DS007786-19
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Page 14
Typical Applications—LM149 (Continued)
Triangular Squarewave Generator
Use LM125 for±15V supply
The circuit can be used as a low frequency V/F for process control.
Q1, Q3: KE4393, Q2, Q4: P1087E, D1–D4=1N914
DS007786-20
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Page 15
Typical Simulation
LM148, LM149, LM741 Macromodel for Computer Simulation
For more details, see IEEE Journal of Solid-State Circuits, Vol. SC-9, No. 6, December 1974
=
Note 6:
Note 7:
112I
o1
=
144
o2
−16
=
8x10
S
*
C2=6 pF for LM149
DS007786-21
DS007786-22
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Page 16
Connection Diagram
Order Number LM148J, LM148J/883, LM149J/883, LM248J, LM348J, LM348M, or LM348N
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.
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