JM38510/11001BC - National Semiconductor

LM148/LM248/LM348

Quad 741 Op Amps

LM149

Wide Band Decompensated (A

V (MIN)

=5)

General Description

The LM148 series is a true quad 741. It consists of four inde-

pendent, high gain, internally compensated, low power op-

erational 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 ther-

mal 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 741 or 1558 type

amplifiers are being used and in applications where amplifier

matching or high packing density is required.

Features

n741 op amp operating characteristics

nLow supply current drain: 0.6 mA/Amplifier

nClass AB output stage—no crossover distortion

nPin compatible with the LM124

nLow input offset voltage: 1 mV

nLow input offset current: 4 nA

nLow input bias current: 30 nA

nGain bandwidth product

LM148 (unity gain): 1.0 MHz

LM149 (A

≥5): 4 MHz

nHigh degree of isolation between amplifiers: 120 dB

nOverload protection for inputs and outputs

Schematic Diagram

DS007786-1

* 1 pF in the LM149

May 1999

LM148/LM149 Series Quad 741 Op Amp

Absolute Maximum Ratings (Note 4)

If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/

Distributors for availability and specifications.

LM148/LM149 LM248 LM348

Supply Voltage ±22V ±18V ±18V

Differential Input Voltage ±44V ±36V ±36V

Output Short Circuit Duration (Note 1) Continuous Continuous Continuous

Power Dissipation (P

at 25˚C) and

Thermal Resistance (θ

), (Note 2)

Molded DIP (N) P

— — 750 mW

— — 100˚C/W

Cavity DIP (J) P

1100 mW 800 mW 700 mW

110˚C/W 110˚C/W 110˚C/W

Maximum Junction Temperature (T

jMAX

) 150˚C 110˚C 100˚C

Operating Temperature Range −55˚C ≤T

≤+125˚C −25˚C ≤T

≤+85˚C 0˚C ≤T

≤+70˚C

Storage Temperature Range −65˚C to +150˚C −65˚C to +150˚C −65˚C to +150˚C

Lead Temperature (Soldering, 10 sec.) Ceramic 300˚C 300˚C 300˚C

Lead Temperature (Soldering, 10 sec.) Plastic 260˚C

Soldering Information

Dual-In-Line Package

Soldering (10 seconds) 260˚C 260˚C 260˚C

Small Outline Package

Vapor Phase (60 seconds) 215˚C 215˚C 215˚C

Infrared (15 seconds) 220˚C 220˚C 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 5) 500V 500V 500V

Electrical Characteristics

(Note 3)

Parameter Conditions LM148/LM149 LM248 LM348 Units

Min Typ Max Min Typ Max Min Typ Max

Input Offset Voltage T

=25˚C, R

≤10 kΩ1.0 5.0 1.0 6.0 1.0 6.0 mV

Input Offset Current T

=25˚C 4 25 4 50 4 50 nA

Input Bias Current T

=25˚C 30 100 30 200 30 200 nA

Input Resistance T

=25˚C 0.8 2.5 0.8 2.5 0.8 2.5 MΩ

Supply Current All Amplifiers T

=25˚C, V

=±15V 2.4 3.6 2.4 4.5 2.4 4.5 mA

Large Signal Voltage Gain T

=25˚C, V

=±15V 50 160 25 160 25 160 V/mV

OUT

=±10V, R

≥2kΩ

Amplifier to Amplifier T

=25˚C, f =1Hzto20kHz

Coupling (Input Referred) See Crosstalk −120 −120 −120 dB

Test Circuit

Small Signal Bandwidth LM148 Series 1.0 1.0 1.0 MHz

=25˚C

LM149 Series 4.0 4.0 4.0 MHz

Phase Margin LM148 Series (A

=1) 60 60 60 degrees

=25˚C

LM149 Series (A

=5) 60 60 60 degrees

Slew Rate LM148 Series (A

=1) 0.5 0.5 0.5 V/µs

=25˚C

LM149 Series (A

=5) 2.0 2.0 2.0 V/µs

Output Short Circuit Current T

=25˚C 25 25 25 mA

Input Offset Voltage R

≤10 kΩ6.0 7.5 7.5 mV

Input Offset Current 75 125 100 nA

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Electrical Characteristics (Continued)

(Note 3)

Parameter Conditions LM148/LM149 LM248 LM348 Units

Min Typ Max Min Typ Max Min Typ Max

Input Bias Current 325 500 400 nA

Large Signal Voltage Gain V

=±15V, V

OUT

=±10V, 25 15 15 V/mV

>2kΩ

Output Voltage Swing V

=±15V, R

=10 kΩ±12 ±13 ±12 ±13 ±12 ±13 V

=2kΩ±

10 ±12 ±10 ±12 ±10 ±12 V

Input Voltage Range V

=±15V ±12 ±12 ±12 V

Common-Mode Rejection R

≤10 kΩ70 90 70 90 70 90 dB

Ratio

Supply Voltage Rejection R

≤10 kΩ,±5V ≤V

≤±15V 77 96 77 96 77 96 dB

Note 1: Any of the amplifier outputs can be shorted to ground indefinitely; however, more than one should not be simultaneously shorted as the maximum junction

temperature will be exceeded.

Note 2: The maximum power dissipation for these devices must be derated at elevated temperatures and is dicated by TjMAX,θjA, and the ambient temperature, TA.

The maximum available power dissipation at any temperature is Pd=(TjMAX −T

)/θjA or the 25˚C PdMAX, whichever is less.

Note 3: These specifications apply for VS=±15V and over the absolute maximum operating temperature range (TL≤TA≤TH) unless otherwise noted.

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 kΩin series with 100 pF.

Cross Talk Test Circuit

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 characteris-

tics 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 ampli-

fier outputs are located in the corners of the package which

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 ad-

dition, if either of the input voltages is within the operating

common-mode range, the phase of the output remains cor-

rect. 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 maxi-

mum supply voltages, either differentially or common-mode,

resistors should be placed in series with the inputs to limit

the current.

DS007786-6 DS007786-7

VS=±15V

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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 re-

sistor 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-

sure stability. For example, resistors from the output to an in-

put should be placed with the body close to the input to mini-

mize “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) toAC

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 feed-

back 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 ca-

pacitor should be such that the RC time constant of this ca-

pacitor and the resistance it parallels is greater than or equal

to the original feedback pole time constant.

Typical Performance Characteristics

Supply Current

DS007786-23

Input Bias Current

DS007786-24

Voltage Swing

DS007786-25

Positive Current Limit

DS007786-26

Negative Current Limit

DS007786-27

Output Impedance

DS007786-28

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Typical Performance Characteristics (Continued)

Common-Mode Rejection

Ratio

DS007786-29

Open Loop Frequency

Response

DS007786-30

Bode Plot LM148

DS007786-31

Bode Plot LM149

DS007786-32

Large Signal Pulse

Response (LM148)

DS007786-33

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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Typical Performance Characteristics (Continued)

Gain Bandwidth

DS007786-38

Slew Rate

DS007786-39

Inverting Large Signal Pulse

Response (LM149)

DS007786-40

Inverting Large Signal Pulse

Response (LM148)

DS007786-41

Input Noise Voltage and

Noise Current

DS007786-42

Positive Common-Mode

Input Voltage Limit

DS007786-43

Negative Common-Mode Input

Voltage Limit

DS007786-5

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Typical Applications—LM148

One Decade Low Distortion Sinewave Generator

DS007786-8

fMAX =5 kHz, THD ≤0.03%

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), VS=±15V

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.

Low Cost Instrumentation Amplifier

DS007786-9

VS=±15V

R=R2, trim R2 to boost CMRR

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Typical Applications—LM148 (Continued)

Low Drift Peak Detector with Bias Current Compensation

DS007786-10

Adjust R for minimum drift

D3 low leakage diode

D1 added to improve speed

VS=±15V

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Typical Applications—LM148 (Continued)

Universal State-Variable Filter

DS007786-11

Tune Q through R0,

For predictable results: fOQ≤4x10

Use Band Pass output to tune for Q

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Typical Applications—LM148 (Continued)

A 1 kHz 4 Pole Butterworth

DS007786-12

Use general equations, and tune each section separately

Q1stSECTION =0.541, Q2ndSECTION =1.306

The response should have 0 dB peaking

A 3 Amplifier Bi-Quad Notch Filter

DS007786-13

Ex: fNOTCH =3 kHz, Q =5, R1 =270k, R2 =R3 =20k, R4 =27k, R5 =20k, R6 =R8 =10k, R7 =100k, C1 =C2 =0.001 µF

Better noise performance than the state-space approach.

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Typical Applications—LM148 (Continued)

A 4th Order 1 kHz Elliptic Filter (4 Poles, 4 Zeros)

DS007786-14

R1C1 =R2C2 =t

R'1C'1 =R'2C'2 =t'

fC=1 kHz, fS=2 kHz, fp=0.543, fZ=2.14, Q =0.841, f' P=0.987, f' Z=4.92, Q' =4.403, normalized to ripple BW

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, RL=100k, RH=155.1k,

R'1 =R'2 =50.9k, R'4 =R'5 =100k, R'6 =10k, R'0 =5.78k, R'L=100k, R'H=248.12k, R'f =100k. All capacitors are 0.001 µF.

Lowpass Response

DS007786-15

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Typical Applications—LM149

Minimum Gain to Insure LM149 Stability

DS007786-16

The LM149 as a Unity Gain Inverter

DS007786-17

Non-inverting-Integrator Bandpass Filter

DS007786-18

For stability purposes: R7 =R6/4, 10R6 =R5, CC=10C

fO(MAX),Q

MAX =20 kHz, 10

Better Q sensitivity with respect to open loop gain variations than the state variable filter.

R7, CCadded for compensation

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Typical Applications—LM149 (Continued)

Active Tone Control with Full Output Swing (No Slew Limiting at 20 kHz)

DS007786-19

VS=±15V, VOUT(MAX) =9.1 VRMS,

fMAX =20 kHz, THD ≤1%

Duplicate the above circuit for stereo

Max Bass Gain ≅(R1 + R2)/R1

Max Treble Gain ≅(R1 + 2R7)/R5

as shown: fL≅32 Hz, fLB ≅320 Hz

fH≅11 kHz, fHB ≅1.1 Hz

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Typical Applications—LM149 (Continued)

Triangular Squarewave Generator

DS007786-20

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

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Typical Simulation

LM148, LM149, LM741 Macromodel for Computer Simulation

DS007786-21

For more details, see IEEE Journal of Solid-State Circuits, Vol. SC-9, No. 6, December 1974

Note 6: o1 =112IS=8x10

−16

Note 7: o2 =144*C2 =6 pF for LM149

DS007786-22

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Connection Diagram

DS007786-2

Top View

Order Number LM148J, LM148J/883, LM149J/883, LM248J, LM348J, LM348M, or LM348N

See NS Package Number J14A, M14A or N14A

LM148J is available per JM38510/11001

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Physical Dimensions inches (millimeters) unless otherwise noted

Ceramic Dual-In-Line Package (J)

Order Number LM148J, LM148J/883, LM149J/883, LM248J or LM348J

NS Package Number J14A

S.O. Package (M)

Order Number LM348M

NS Package Number M14A

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Physical Dimensions inches (millimeters) unless otherwise noted (Continued)

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DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT AND GENERAL

COUNSEL OF NATIONAL SEMICONDUCTOR CORPORATION. As used herein:

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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

labeling, can be reasonably expected to result in a

significant injury to the user.

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.

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Molded Dual-In-Line Package (N)

Order Number LM348N

NS Package Number N14A

LM148/LM149 Series Quad 741 Op Amp

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.