Device Operating
Temperature Range Package
SEMICONDUCTOR
TECHNICAL DATA
SUPER GAIN
OPERATIONAL AMPLIFIER
ORDERING INFORMATION
LM308AN
LM308AD TA = 0° to +70°CPlastic DIP
SO–8
Order this document by LM308A/D
Compen A Compen B
Inputs Output
VCC
NC
VEE
(Top View)
D SUFFIX
PLASTIC PACKAGE
CASE 751
(SO–8)
N SUFFIX
PLASTIC PACKAGE
CASE 626
1
2
3
4
8
7
6
5
8
1
81
PIN CONNECTIONS
+
–
1
MOTOROLA ANALOG IC DEVICE DATA
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
R2
Frequency Compensation
Standard Compensation Modified Compensation
R2
R1
R3
Compen A
Output
Compen B
Inverting
Input
Noninverting
Input
Cf
≥
30 1
1 + R2
R1
Cf
Standard Feedforward
Compensation Feedforward Compensations for
Decoupling Load Capacitance
Input 10 k 5.0 pF
10
k
Output
Compen B
3.0 k
10 pF
Compen A
500 pF
Input
Output
500
10 pFC2*
Compen B
10 pF
500 pF 3.0 k CL
75 pF to
0.01
µ
F
*C2 > 5 x 105pF
R1
R3 Output
Compen B
Inverting
Input
Noninverting
Input 100 pF
R2
RS > 10 k 100 k
0.01
µ
F
Compen A
+
++
+
Motorola, Inc. 1996 Rev 0
LM308A
2MOTOROLA ANALOG IC DEVICE DATA
MAXIMUM RATINGS (TA = +25°C, unless otherwise noted.)
Rating Symbol Value Unit
Power Supply Voltage VCC, VEE ±18 Vdc
Input Voltage (See Note 1) VI±15 V
Input Differential Current ( See Note 2) IID ±10 mA
Output Short Circuit Duration tSC
Indefinite
Operating Ambient Temperature Range TA0 to +70 °C
Storage Temperature Range Tstg –65 to +150 °C
Junction Temperature TJ+150 °C
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 ≤ VCC ≤ +15 V
and –5.0 V ≥ VEE ≥–15 V, TA = +25°C.)
Characteristic Symbol Min Typ Max Unit
Input Offset Voltage VIO –0.3 0.5 mV
Input Offset Current IIO –0.2 1.0 nA
Input Bias Current IIB –1.5 7.0 nA
Input Resistance ri10 40 – MΩ
Power Supply Currents ICC, IEE –±0.3 ±0.8 mA
(VCC = +15 V, VEE = –15 V)
Large Signal Voltage Gain AVOL 80 300 – V/mV
(VCC = +15 V, VEE = –15 V, VO = ±10 V, RL ≥ 10 kΩ)
The following specifications apply over the operating temperature range.
Input Offset Voltage VIO – – 0.73 mV
Input Offset Current IIO – – 1.5 nA
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 IIB – – 10 nA
Large Signal Voltage Gain AVOL 60 – – V/mV
(VCC +15 V, VEE = –15 V, VO = ±10 V, RL ≥ 10 kΩ)
Input Voltage Range VICR ±14 – – 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)VOR ±13 ±14 – V
LM308A
3
MOTOROLA ANALOG IC DEVICE DATA
200
AVOL, VOLTAGE GAIN (dB)
ICC
=
IEE , SUPPLY CURRENTS ( A)
µ
VOR, OUTPUT VOLTAGE RANGE ( V
±
p–p)
VCC =
VEE
, SUPPLY VOLTAGES (V)
f, FREQUENCY (Hz) f, FREQUENCY (Hz)
130
120
110
100
90
80 0 5.0 10 15 20
500
400
300
100
00 5.0 10
VCC =
VEE
, SUPPLY VOLTAGES (V)
140
120
100
80
60
40
20
0
–20
1.0 10 100 1.0 k 10 k 100 k 1.0 M 10 M 100 M
20
16
12
8.0
4.0
01.0 k 10 k 100 k 1.0 M
15 20
AVOL, VOLT AGE GAIN (dB)
Figure 1. Input Bias and Input Offset Currents Figure 2. Maximum Equivalent Input Offset
Voltage Error versus Input Resistance
IIB, INPUT BIAS CURRENT (nA)
EQUIVALENT INPUT OFFSET VOLTAGE (mV)
T, TEMPERATURE (
°
C) ri, INPUT RESISTANCE (
Ω
)
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
–60 –40 –20 0 20 40 60 80 100 120 140
0.25
0.20
0.15
0.10
0.05
0
100
10
1.0
0.1
100 k 1.0 M 10 M 100 M
IIO, INPUT OFFSET CURRENT (nA)
CF = 3.0 pF
Figure 3. Voltage Gain versus Supply Voltages Figure 4. Power Supply Currents versus
Power Supply Voltages
Figure 5. Open Loop Frequency Response Figure 6. Large Signal Frequency Response
IIO
IIB
CF = 30 pF
CF = 100 pF
CF = 0
f = 100 Hz
0
°
C
TA = 0
°
C
+25
°
C
–55
°
C
+70
°
C
+125
°
C
TA = –55
°
C
+25
°
C
+70
°
C
+125
°
C
CF = 30 pF
CF = 3.0 pF
VCC = +15 V
VEE = –15 V
TA = +25
°
C
LM308A
4MOTOROLA ANALOG IC DEVICE DATA
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
(1) Power Bandwidth: 250 kHz
Small Signal Bandwidth:
3.5 MHz
Slew Rate: 10 V/
µ
s
(2) C5 = 6 X 10–8
R1
(3) In addition to increasing speed,
the LM101A raises high and low
frequency gain, increases output
drive capability and eliminates
thermal feedback.
RS C5 (2)
Input R1 R4
150 pF
16
2
3
1.0 M
Output
LM101A (3)
or equiv
Compen B
1 M
R2
LM308A
0.002
µ
F0.002
µ
F
300 pF
150 k
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
(1) Teflon, Polyethylene or Polycarbonate
Dielectric Capacitor
Output
30 pF
Q1
Q2
Input
Sample
VCC 1.0 M
1.0
µ
F (1)
Figure 9. Connection of Input Guards
Inverting Amplifier Follower Noninverting Amplifier
(1) Used to compensate for large source resistances. Note: R1 R2
R1 +R2 must be an impedance.
C1
R1 R2
Input
Output
R3 (1) C1
Input Output
R3 (1)
C1
R2
Input
Output
R1
R3 (1)
LM308A
5
MOTOROLA ANALOG IC DEVICE DATA
Representative Circuit Schematic
VCC
Output
Compensation A Compensation B
200
65
150
VEE
1.0 k
1.4 k
7.5 k5.6 k3.5 k
7.0 k
1.0 k
VCC
VEE
20 k
362 1.2 k 50 k
80 k
10 k
2.0 k
17.4 k
15 pF
Inputs
)
2.0 k
7.5 k
1.0 k
17.4 k
LM308A
6MOTOROLA ANALOG IC DEVICE DATA
OUTLINE DIMENSIONS
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.
14
58
F
NOTE 2 –A–
–B–
–T–
SEATING
PLANE
H
J
GDK
N
C
L
M
M
A
M
0.13 (0.005) B M
T
DIM MIN MAX MIN MAX
INCHESMILLIMETERS
A9.40 10.16 0.370 0.400
B6.10 6.60 0.240 0.260
C3.94 4.45 0.155 0.175
D0.38 0.51 0.015 0.020
F1.02 1.78 0.040 0.070
G2.54 BSC 0.100 BSC
H0.76 1.27 0.030 0.050
J0.20 0.30 0.008 0.012
K2.92 3.43 0.115 0.135
L7.62 BSC 0.300 BSC
M––– 10 ––– 10
N0.76 1.01 0.030 0.040
__
D SUFFIX
PLASTIC PACKAGE
CASE 751–05
(SO–8)
ISSUE R
N SUFFIX
PLASTIC PACKAGE
CASE 626–05
ISSUE K
SEATING
PLANE
14
58
A0.25 MCBSS
0.25 MBM
h
q
C
X 45
_
L
DIM MIN MAX
MILLIMETERS
A1.35 1.75
A1 0.10 0.25
B0.35 0.49
C0.18 0.25
D4.80 5.00
E1.27 BSCe3.80 4.00
H5.80 6.20
h
0 7
L0.40 1.25
q
0.25 0.50
__
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.
D
EH
A
Be
B
A1
CA
0.10
LM308A
7
MOTOROLA ANALOG IC DEVICE DATA
Motorola reserves the right to make changes without further notice to any products herein. Motorola makes no warranty, representation or guarantee regarding
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. “Typical” 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
others. Motorola products are not designed, intended, or authorized for use as components in systems intended for surgical implant into the body, or other
applications intended to support or sustain life, or for any other application in which the failure of the Motorola product could create a situation where personal injury
or death may occur. Should Buyer purchase or use Motorola products for any such unintended or unauthorized application, Buyer shall indemnify and hold Motorola
and its officers, employees, subsidiaries, affiliates, and distributors harmless against all claims, costs, damages, and expenses, and reasonable attorney fees
arising out of, directly or indirectly, any claim of personal injury or death associated with such unintended or unauthorized use, even if such claim alleges that
Motorola was negligent regarding the design or manufacture of the part. Motorola and are registered trademarks of Motorola, Inc. Motorola, Inc. is an Equal
Opportunity/Af firmative Action Employer .
LM308A
8MOTOROLA ANALOG IC DEVICE DATA
How to reach us:
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LM308A/D
*LM308A/D*
◊
