LP124.PDF

February 1995

LP124/LP2902/LP324 Micropower Quad

Operational Amplifier

General Description

The LP124 series consists of four independent, high gain

internally compensated micropower operational amplifiers.

These amplifiers are specially suited for operation in battery

systems while maintaining good input specifications, and

extremely low supply current drain. In addition, the LP124

has an input common mode range, and output source range

which includes ground, making it ideal in single supply appli-

cations.

These amplifiers are ideal in applications which include por-

table instrumentation, battery backup equipment, and other

circuits which require good DC performance and low supply

current.

Features

Y Low supply current

125 m A (max)

Y Low offset voltage

2 mV (max)

Y Low input bias current

4 nA (max)

Y Input common mode to GND

Y Interfaces to CMOS logic

Y Wide supply range

3V k V a k 32V

Y Small Outline Package available

Y Pin-for-pin compatible with LM124

Connection Diagram

Simplified Schematic

Dual-in-Line (J, N) and SO (M)

TL/H/8562±1

Order Number LP124J or LP324J

See NS Package Number J14A

Order Number LP324M or LP2902M

See NS Package Number M14A

Order Number LP324N or LP2902N

See NS Package Number N14A

TL/H/8562±2

C 1996 National Semiconductor Corporation

TL/H/8562

RRD-B30M56/Printed in U. S. A.

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Absolute Maximum Ratings

If Military/Aerospace specified devices are required,

please contact the National Semiconductor Sales

Office/Distributors for availability and specifications.

Supply Voltage

Operating Conditions

Package

Power Dissipation

500 mW 500 mW 500 mW

32V or g 16V

(Note 3)

T j Max 150 § C 150 § C 150 § C

i ja 90 § C/W 90 § C/W 140 § C/W

Operating Temp. Range (Note 4) (Note 4)

LP2902

26V or g 13V

Differential Input Voltage

32V

LP2902

26V

(Note 4)

Input Voltage (Note 1)

b 0.3V to 32V

Storage Temp. Range

b 65 § C s T s 150 § C

LP2902

b 0.3V to 26V

Soldering

Information (10 sec.) 300 § C 260 § C

Vapor Phase (60 sec.)

Output Short-Circuit to GND

Continuous

(One Amplifier) (Note 2)

V a s 15V and T A e 25 § C

ESD Susceptibility (Note 9)

215 § C

Infrared (15 sec.)

220 § C

g 500V

Electrical Characteristics (Note 5)

LP124

LP2902 (Note 8)

LP324

Symbol Parameter Conditions

Tested Design Tested Design Tested Design Units

Typ Limit Limit Typ Limit Limit Typ Limit Limit Limits

(Note 6) (Note 7)

V os

Input Offset

7 2

10 2

4 9 mV

Voltage

(Max)

I b

Input Bias

8 2 20

40 2 10

20 nA

Current

(Max)

I os

Input Offset

0.1 1

2 0.5 4

8 0.2 2

Current

(Max)

A vol Voltage R L e 10k

100 70

60 70 40

30 100 50

40 V/mV

Gain

to GND

(Min)

V a e 30V

CMRR Common V a e 30V

100 85

75 90 80

75 dB

Mode Rej. 0V s V cm

(Min)

Ratio

V cm k V a b 1.5

PSRR Power

V a e 5V to 30V 100 85

75 90 80

75 dB

Supply Rej.

(Min)

Ratio

I s

Supply

R L e % 85 125 200 85 150 250 85 150 250 m A

Current

150

(Max)

V o Output

I L e 350 m A

3.6 3.4 V a b 1.9V 3.6 3.4 V a b 1.9V 3.6 3.4 V a b 1.9V V

Voltage

to GND.

3.1

(Min)

Swing

V cm e 0V

I L e 350 m A

to V a

0.7 0.8 1.0 0.7 0.8 1.0 0.7 0.8 1.0 V

1.0

(Max)

V cm e 0V

I out Output

V o e 3V

11 9

4 10 7

4 mA

Source Source

V in (diff) e 1V

(Min)

Current

I out Output

V o e 1.5V

4 5

4 3 5

4 3 mA

Sink Sink

V in (diff) e 1V

(Min)

Current

I out Output

V o e 1.5V

1.5 4

2 1 4

2 1 mA

Sink Sink

V cm e 0V

0.5

(Min)

Current

I source Output

V in (diff) e 1V 20 25

35 20 25

35 mA

Short to GND

(Max)

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Electrical Characteristics (Note 5) (Continued)

LP124

LP2902 (Note 8)

LP324

Symbol Parameter Conditions

Tested Design Tested Design Tested Design Units

Typ Limit Limit Typ Limit Limit Typ Limit Limit Limits

(Note 6) (Note 7)

I sink Output

V in (diff) e 1V 15 30 45 15 30 45 15 30 45 mA

Short to V a

(Max)

V os

m V/C §

Drift

I os

pA/C §

Drift

GBW Gain

Bandwidth

100

KHz

Product

S r Slew Rate 50 50 50 V/mS

Note 1: The input voltage is not allowed to go more than b 0.3V below V b (GND) as this will turn on a parasitic transistor causing large currents to flow through the

device.

Note 2: Short circuits from the output to GND can cause excessive heating and eventual destruction. The maximum sourcing output current is approximately 30 mA

independent of the magnitude of V a . At values of supply voltage in excess of 15 V DC , continuous short-circuit to GND can exceed the power dissipation ratings

(particularly at elevated temperatures) and cause eventual destruction. Destructive dissipation can result from simultaneous shorts on all amplifiers.

Note 3: For operation at elevated temperatures, these devices must be derated based on a thermal resistance of i ja and T j max. T j e T A a i ja P D .

Note 4: The LP124 may be operated from b 55 § C s T A s a 125 § C. The LP2902 may be operated from b 40 § C s T A s a 85 § C, and the LP324 may be operated

from 0 § C s T A s a 70 § C.

Note 5: Boldface numbers apply at temperature extremes. All other numbers apply only at T A e T j e 25 § C, V a e 5V, V cm e V/2, and R L e 100k

connected to GND unless otherwise specified.

Note 6: Guaranteed and 100% production tested.

Note 7: Guaranteed (but not 100% production tested) over the operating supply voltage range (3.0V to 32V for the LP124, LP324, and 3.0V to 26V for the LP2902),

and the common mode range (0V to V a b 1.5V), unless otherwise specified. These limits are not used to calculate outgoing quality levels.

Note 8: The LP2902 operating supply range is 3V to 26V, and is not tested above 26V.

Note 9: The test circuit used consists of the human body model of 100 pF in series with 1500 X .

Typical Performance Curves

Input Voltage Range

Input Current

Supply Current

Open Loop

Power Supply

Voltage Gain

Frequency Response

Rejection Ratio

TL/H/8562±18

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Typical Performance Curves (Continued)

Voltage Follower

Voltage Follower Pulse

Common Mode

Pulse Response

Response (Small Signal)

Rejection Ratio

TL/H/8562±20

Large Signal

Output Characteristics

Frequency Response

Current Sourcing

Current Sinking

Current Limiting

TL/H/8562±19

Application Hints

The LP124 series is a micro-power pin-for-pin equivalent to

the LM124 op amps. Power supply current, input bias cur-

rent, and input offset current have all been reduced by a

factor of 10 over the LM124. Like its predecessor, the

LP124 series op amps can operate on single supply, have

true-differential inputs, and remain in the linear mode with

an input common-mode voltage of 0 V DC .

The pinouts of the package have been designed to simplify

PC board layouts. Inverting inputs are adjacent to outputs

for all of the amplifiers and the outputs have also been

placed at the corners of the package (pins 1, 7, 8, and 14).

Precautions should be taken to insure that the power supply

for the integrated circuit never becomes reversed in polarity

or the unit is not inadvertently installed backwards in the

test socket as an unlimited current surge through the result-

ing forward diode within the IC could destroy the unit.

Large differential input voltages can be easily accommodat-

ed and, as input differential voltage protection diodes are

not needed, no large input currents result from large differ-

ential input voltages. The differential input voltage may be

larger than V a without damaging the device. Protection

should be provided to prevent the input voltages from going

negative more than b 0.3 V DC (at 25 § C). An input clamp

diode with a resistor to the IC input terminal can be used.

The amplifiers have a class B output stage which allows the

amplifiers to both source and sink output currents. In appli-

cations where crossover distortion is undesirable, a resistor

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Application Hints (Continued)

should be used from the output of the amplifier to ground.

The resistor biases the output into class A operation.

The LP124 has improved stability margin for driving capaci-

tive loads. No special precautions are needed to drive loads

in the 50 pF to 1000 pF range. It should be noted however

that since the power supply current has been reduced by a

factor of 10, so also has the slew rate and gain bandwidth

product. This reduction can cause reduced performance in

AC applications where the LM124 is being replaced by an

LP124. Such situations usually occur when the LM124 has

been operated near its power bandwidth.

Output short circuits either to ground or to the positive pow-

er supply should be of short time duration. Units can be

destroyed, not as a result of the short circuit current causing

metal fusing, but rather due to the large increase in IC chip

dissipation which will cause eventual failure due to exces-

sive junction temperatures. For example: If all four amplifi-

ers were simultaneously shorted to ground on a 10V supply

the junction temperature would rise by 110 § C.

Exceeding the negative common-mode limit on either input

will cause a reversal of phase to the output and force

the amplifier to the corresponding high or low state. Exceed-

ing the negative common-mode limit on both inputs will

force the amplifier output to a high state. Exceeding the

positive common-mode limit on a single input will not

change the phase of the output. However, if both inputs

exceed the limit, the output of the amplifier will be forced to

a low state. In neither case does a latch occur since return-

ing the input within the common mode range puts the input

stage and thus the amplifier in a normal operating mode.

The circuits presented in the section on typical applications

emphasize operation on only a single power supply voltage.

If complementary power supplies are available, all of the

standard op amp circuits can be used. In general, introduc-

ing a pseudo-ground (a bias voltage reference to V a /2) will

allow operation above and below this value in single power

supply systems. Many application circuits are shown which

take advantage of the wide input common-mode voltage

range which includes ground. In most cases, input biasing is

not required and input voltages which range to ground can

easily be accommodated.

Driving CMOS

Comparator with Hysteresis

TL/H/8562±3

TL/H/8562±6

Non-Inverting Amplifier

Adder/Subtractor

TL/H/8562±4

TL/H/8562±7

Unity Gain Buffer

Positive Integrator

TL/H/8562±5

TL/H/8562±8

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