Datasheet LM308AD, LM308AN Datasheet (Motorola)

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The LM308A operational amplifier provides high input impedance, low
input offset and temperature drift, and low noise. These characteristics are
made possible by use of a special Super Beta processing technology. This
amplifier is particularly useful for applications where high accuracy and low
drift performance are essential. In addition high speed performance may be
improved by employing feedforward compensation techniques to maximize
slew rate without compromising other performance criteria.

The LM308A offers extremely low input offset voltage and drift
specifications allowing usage in even the most critical applications without
external offset nulling.

• Operation from a Wide Range of Power Supply Voltages

• Low Input Bias and Offset Currents

• Low Input Offset Voltage and Guaranteed Offset Voltage Drift

Performance

• High Input Impedance

Frequency Compensation

Standard Compensation

Input

Input

R1

R3

Compen A

Inverting

Noninverting

+

R2

C

f

Cf

Compen B

≥

30

1 +

Output

1

R2
R1

Modified Compensation

Inverting

Noninverting

R1

Input

R3

Input

+

100 pF

R2

Output

Compen B

SUPER GAIN

OPERATIONAL AMPLIFIER

SEMICONDUCTOR

TECHNICAL DATA

8

1

N SUFFIX

PLASTIC PACKAGE

CASE 626

8

1

D SUFFIX

PLASTIC PACKAGE

CASE 751

(SO–8)

PIN CONNECTIONS

Standard Feedforward

Compensation

10 k

Input

500 pF

Compen A

5.0 pF
10

k

+

Compen B

3.0 k
10 pF

Output

Feedforward Compensations for

Decoupling Load Capacitance

RS > 10 k

Input

0.01

MOTOROLA ANALOG IC DEVICE DATA

Compen A Compen B

Inputs

100 k

10 pFC2*

µ

F

+

3.0 k

500 pF

Compen A

500

Compen B

10 pF

*C2 >

5 x 10

R2

Output

C

L

75 pF to

0.01

µ

F

5

pF

Device

LM308AN
LM308AD

 Motorola, Inc. 1996 Rev 0

1

–

2

+

3

4

V

EE

(Top View)

ORDERING INFORMATION

Operating

Temperature Range

TA = 0° to +70°C

8

7

6

5

V
Output
NC

CC

Package

Plastic DIP

SO–8

1

LM308A

MAXIMUM RATINGS (T

Power Supply Voltage V
Input Voltage (See Note 1) V
Input Differential Current ( See Note 2) I
Output Short Circuit Duration t
Operating Ambient Temperature Range T
Storage Temperature Range T
Junction Temperature T

NOTES: 1. For supply voltages less than ±15 V , the maximum input voltage is equal to the supply

voltage.

2.The inputs are shunted with back–to–back diodes for overvoltage protection. Therefore,
excessive current will flow if a differential input voltage in excess of 1.0 V is applied
between the inputs, unless some limiting resistance is used.

ELECTRICAL CHARACTERISTICS (Unless otherwise noted these specifications apply for supply voltages of +5.0 V ≤ V

and –5.0 V ≥ VEE ≥ –15 V, TA = +25°C.)

Input Offset Voltage V
Input Offset Current I
Input Bias Current I
Input Resistance r
Power Supply Currents ICC, I

(VCC = +15 V, VEE = –15 V)

Large Signal Voltage Gain A

(VCC = +15 V, VEE = –15 V, VO = ±10 V, RL ≥ 10 kΩ)

The following specifications apply over the operating temperature range.

Input Offset Voltage V
Input Offset Current I
Average Temperature Coefficient of Input Offset Voltage ∆VIO/∆T – 1.0 5.0 µV/°C

TA (min) ≤ TA ≤ TA (max)
Average Temperature Coefficient of Input Offset Current ∆IIO/∆T – 2.0 10 pA/°C
Input Bias Current I
Large Signal Voltage Gain A

(VCC +15 V, VEE= –15 V, VO = ±10 V, RL ≥ 10 kΩ)
Input Voltage Range V

(VCC = +15 V, VEE= –15 V)
Common Mode Rejection CMR 96 110 – dB

(RS ≤ 50 kΩ)
Supply Voltage Rejection PSR 96 110 – dB

(RS ≤ 50 kΩ)
Output Voltage Range

(VCC = +15 V, VEE= –15 V, RL = 10 kΩ)

= +25°C, unless otherwise noted.)

A

Rating Symbol Value Unit

CC, VEE

I

ID

SC

A

stg

J

Characteristic

±18 Vdc
±15 V
±10 mA

Indefinite

0 to +70 °C

–65 to +150

+150 °C

Symbol Min Typ Max Unit

IO
IO
IB

i

VOL

IO
IO

IB

VOL

ICR

V

OR

°C

EE

≤ +15 V

CC

– 0.3 0.5 mV
– 0.2 1.0 nA
– 1.5 7.0 nA

10 40 – MΩ

– ±0.3 ±0.8 mA

80 300 – V/mV

– – 0.73 mV
– – 1.5 nA

– – 10 nA

60 – – V/mV

±14 – – V

±13 ±14 – V

2

MOTOROLA ANALOG IC DEVICE DATA

Figure 1. Input Bias and Input Offset Currents

2.0

1.8

1.6

1.4

1.2

1.0

0.8

, INPUT BIAS CURRENT (nA)

0.6

IB

I

0.4

0.2
0

–60 –40 –20 0 20 40 60 80 100 120 140

T, TEMPERATURE (°C) ri, INPUT RESISTANCE (Ω)

I

IO

I

IB

Figure 3. V oltage Gain versus Supply Voltages

130

120

TA = 0°C

110

100

, VOLTAGE GAIN (dB)

VOL

A

90

80

+25°C
–55°C
+70°C

+125°C

CF = 0
f = 100 Hz

0 5.0 10 15 20

VCC = VEE

, SUPPLY VOLTAGES (V)

LM308A

0.25

0.20

0.15

0.10

, INPUT OFFSET CURRENT (nA)

0.05
IO

I

0

Figure 2. Maximum Equivalent Input Offset

V oltage Error versus Input Resistance

100

10

1.0

0.1

EQUIVALENT INPUT OFFSET VOLTAGE (mV)

100 k 1.0 M 10 M 100 M

Figure 4. Power Supply Currents versus

Power Supply Voltages

500

µ

400

TA = –55°C

300

200

, SUPPLY CURRENTS ( A)

EE

I

100

=

CC

I

0

0 5.0 10

0°C

+25°C
+70°C

+125°C

VCC =



VEE

, SUPPLY VOLTAGES (V)

15 20

Figure 5. Open Loop Frequency Response Figure 6. Large Signal Frequency Response

140
120
100

80
60
40

, VOLTAGE GAIN (dB)

20

VOL

A

0

–20

1.0 10 100 1.0 k 10 k 100 k 1.0 M 10 M 100 M

CF = 3.0 pF

CF = 30 pF

CF = 100 pF

f, FREQUENCY (Hz) f, FREQUENCY (Hz)

MOTOROLA ANALOG IC DEVICE DATA

20

)

p–p

16

±

12

8.0

4.0

, OUTPUT VOL TAGE RANGE ( V

OR

V

CF = 30 pF

0

1.0 k 10 k 100 k 1.0 M

CF = 3.0 pF

VCC = +15 V
VEE = –15 V

°

C

TA = +25

3

LM308A

SUGGESTED DESIGN APPLICATIONS

INPUT GUARDING

Special care must be taken in the assembly of printed
circuit boards to take full advantage of the low input currents
of the LM308A amplifier. Boards must be thoroughly cleaned
with alcohol and blown dry with compressed air. After
cleaning, the boards should be coated with epoxy or silicone
rubber to prevent contamination.

Figure 7. Fast (1) Summing Amplifier with

Low Input Current

Input

RS

R1

150 k

(1) Power Bandwidth: 250 kHz

Small Signal Bandwidth:

3.5 MHz

Slew Rate: 10 V/

(2) C5 =

6 X 10

R1

0.002µF

LM308A

µ

s

–8

Compen B

300 pF

R2

1 M

(3) In addition to increasing speed,

C5 (2)

R4

0.002

µ

2
3

1.0 M

the LM101A raises high and low
frequency gain, increases output
drive capability and eliminates
thermal feedback.

F

150 pF

1

6

LM101A (3)

or equiv

Output

Even with properly cleaned and coated boards, leakage
currents may cause trouble at +125°C, particularly since the
input pins are adjacent to pins that are at supply potentials.
This leakage can be significantly reduced by using guarding
to lower the voltage difference between the inputs and
adjacent metal runs. The guard, which is a conductive ring
surrounding the inputs, is connected to a low–impedance
point that is at approximately the same voltage as the inputs.
Leakage currents from high voltage pins are then absorbed
by the guard.

Figure 8. Sample and Hold

V

CC

Q1

Q2

F (1)

1.0 M

Output

30 pF

Input

Sample

1.0

µ

(1) Teflon, Polyethylene or Polycarbonate

Dielectric Capacitor

Figure 9. Connection of Input Guards

Inverting Amplifier Follower Noninverting Amplifier

Input

(1) Used to compensate for large source resistances. Note:

4

R1 R2

R3 (1)

C1

Output

R3 (1)

Output

Input

C1

MOTOROLA ANALOG IC DEVICE DATA

R2

R3 (1)

R1

Input

R1 R2

must be an impedance.

R1 +R2

Output

C1

15 pF

LM308A

Representative Circuit Schematic

Compensation A Compensation B

7.5 k5.6 k3.5 k

17.4 k

17.4 k

7.5 k

1.0 k

1.4 k

V

CC

Inputs

)

2.0 k

10 k

2.0 k

80 k

1.0 k

7.0 k

V

CC

1.0 k
V

EE

20 k

362 1.2 k 50 k

200

65

150

Output

V

EE

MOTOROLA ANALOG IC DEVICE DATA

5

NOTE 2

–T–

SEATING
PLANE

H

OUTLINE DIMENSIONS

58

–B–

14

F

–A–

C

N

D

G

0.13 (0.005) B

K

M

T

LM308A

N SUFFIX

PLASTIC PACKAGE

CASE 626–05

ISSUE K

L

J

M

M

A

M

NOTES:

1. DIMENSION L TO CENTER OF LEAD WHEN
FORMED PARALLEL.

2. PACKAGE CONTOUR OPTIONAL (ROUND OR
SQUARE CORNERS).

3. DIMENSIONING AND TOLERANCING PER ANSI
Y14.5M, 1982.

DIM MIN MAX MIN MAX

A 9.40 10.16 0.370 0.400
B 6.10 6.60 0.240 0.260
C 3.94 4.45 0.155 0.175
D 0.38 0.51 0.015 0.020
F 1.02 1.78 0.040 0.070
G 2.54 BSC 0.100 BSC
H 0.76 1.27 0.030 0.050
J 0.20 0.30 0.008 0.012
K 2.92 3.43 0.1 15 0.135
L 7.62 BSC 0.300 BSC
M ––– 10 ––– 10
N 0.76 1.01 0.030 0.040

INCHESMILLIMETERS

__

A

C

A1

D SUFFIX

PLASTIC PACKAGE

CASE 751–05

(SO–8)

ISSUE R

D

58

0.25MB

E

1

B

e

H

4

M

h

X 45

_

q

C

A

SEATING
PLANE

0.10

L

B

SS

A0.25MCB

NOTES:

1. DIMENSIONING AND TOLERANCING PER ASME
Y14.5M, 1994.

2. DIMENSIONS ARE IN MILLIMETERS.

3. DIMENSION D AND E DO NOT INCLUDE MOLD
PROTRUSION.

4. MAXIMUM MOLD PROTRUSION 0.15 PER SIDE.

5. DIMENSION B DOES NOT INCLUDE MOLD
PROTRUSION. ALLOWABLE DAMBAR
PROTRUSION SHALL BE 0.127 TOTAL IN EXCESS
OF THE B DIMENSION AT MAXIMUM MATERIAL
CONDITION.

MILLIMETERS

DIM MIN MAX

A 1.35 1.75

A1 0.10 0.25

B 0.35 0.49
C 0.18 0.25
D 4.80 5.00
E

3.80 4.00

1.27 BSCe

H 5.80 6.20

h

0.25 0.50

L 0.40 1.25

0 7

q

__

6

MOTOROLA ANALOG IC DEVICE DATA

LM308A

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the suitability of its products for any particular purpose, nor does Motorola assume any liability arising out of the application or use of any product or circuit, and
specifically disclaims any and all liability, including without limitation consequential or incidental damages. “T ypical” parameters which may be provided in Motorola
data sheets and/or specifications can and do vary in different applications and actual performance may vary over time. All operating parameters, including “Typicals”
must be validated for each customer application by customer’s technical experts. Motorola does not convey any license under its patent rights nor the rights of
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Opportunity/Affirmative Action Employer.

MOTOROLA ANALOG IC DEVICE DATA

7

LM308A

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MOTOROLA ANALOG IC DEVICE DATA

LM308A/D

*LM308A/D*