LF147/LF347
Wide Bandwidth Quad JFET Input Operational Amplifiers
General Description
The LF147 is a low cost, high speed quad JFET input opera-
tional amplifier with an internally trimmed input offset voltage
(BI-FET II
TM
technology). The device requires a low supply
current and yet maintains a large gain bandwidth product
and a fast slew rate. In addition, well matched high voltage
JFET input devices provide very low input bias and offset
currents. The LF147 is pin compatible with the standard
LM148. This feature allows designers to immediately up-
grade the overall performance of existing LF148 and LM124
designs.
The LF147 may be used in applications such as high speed
integrators, fast D/A converters, sample-and-hold circuits
and many other circuits requiring low input offset voltage,
low input bias current, high input impedance, high slew rate
and wide bandwidth. The device has low noise and offset
voltage drift.
Features
n
Internally trimmed offset voltage:
5 mV max
n
Low input bias current:
50 pA
n
Low input noise current:
0.01 pA/
Hz
n
Wide gain bandwidth:
4 MHz
n
High slew rate:
13 V/s
n
Low supply current:
7.2 mA
n
High input impedance:
10
12
n
Low total harmonic distortion:
0.02%
n
Low 1/f noise corner:
50 Hz
n
Fast settling time to 0.01%:
2 s
Simplified Schematic
Connection Diagram
BI-FET II
TM
is a trademark of National Semiconductor Corporation.
1
/
4
Quad
DS005647-13
Dual-In-Line Package
DS005647-1
Note 1: LF147 available as per JM38510/11906.
Top View
Order Number LF147J, LF147J-SMD, LF347M,
LF347BN, LF347N, LF147J/883,
or JL147 BCA (Note 1)
See NS Package Number J14A, M14A or N14A
August 2000
LF147/LF347
W
ide
Bandwidth
Quad
JFET
Input
Operational
Amplifiers
2000 National Semiconductor Corporation
DS005647
www.national.com
Absolute Maximum Ratings
(Note 2)
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
LF147
LF347B/LF347
Supply Voltage
22V
18V
Differential Input Voltage
38V
30V
Input Voltage Range
19V
15V
(Note 3)
Output Short Circuit
Continuous
Continuous
Duration (Note 4)
Power Dissipation
900 mW
1000 mW
(Notes 5, 11)
T
j
max
150C
150C
jA
Ceramic DIP (J) Package
70C/W
Plastic DIP (N) Package
75C/W
Surface Mount Narrow (M)
100C/W
LF147
LF347B/LF347
Surface Mount Wide (WM)
85C/W
Operating Temperature
(Note 6)
(Note 6)
Range
Storage Temperature
Range
-65C
T
A
150C
Lead Temperature
(Soldering, 10 sec.)
260C
260C
Soldering Information
Dual-In-Line Package
Soldering (10 seconds)
260C
Small Outline Package
Vapor Phase (60 seconds)
215C
Infrared (15 seconds)
220C
See AN-450 "Surface Mounting Methods and Their Effect
on Product Reliability" for other methods of soldering
surface mount devices.
ESD Tolerance (Note 12)
900V
DC Electrical Characteristics
(Note 7)
Symbol
Parameter
Conditions
LF147
LF347B
LF347
Units
Min
Typ
Max
Min
Typ
Max
Min
Typ
Max
V
OS
Input Offset Voltage
R
S
=10 k
, T
A
=25C
1
5
3
5
5
10
mV
Over Temperature
8
7
13
mV
V
OS
/
T
Average TC of Input Offset
R
S
=10 k
10
10
10
V/C
Voltage
I
OS
Input Offset Current
T
j
=25C, (Notes 7, 8)
25
100
25
100
25
100
pA
Over Temperature
25
4
4
nA
I
B
Input Bias Current
T
j
=25C, (Notes 7, 8)
50
200
50
200
50
200
pA
Over Temperature
50
8
8
nA
R
IN
Input Resistance
T
j
=25C
10
12
10
12
10
12
A
VOL
Large Signal Voltage Gain
V
S
=
15V, T
A
=25C
50
100
50
100
25
100
V/mV
V
O
=
10V, R
L
=2 k
Over Temperature
25
25
15
V/mV
V
O
Output Voltage Swing
V
S
=
15V, R
L
=10 k
12
13.5
12
13.5
12
13.5
V
V
CM
Input Common-Mode Voltage
V
S
=
15V
11
+15
11
+15
11
+15
V
Range
-12
-12
-12
V
CMRR
Common-Mode Rejection Ratio
R
S
10 k
80
100
80
100
70
100
dB
PSRR
Supply Voltage Rejection Ratio
(Note 9)
80
100
80
100
70
100
dB
I
S
Supply Current
7.2
11
7.2
11
7.2
11
mA
LF147/LF347
www.national.com
2
AC Electrical Characteristics
(Note 7)
Symbol
Parameter
Conditions
LF147
LF347B
LF347
Units
Min
Typ
Max
Min
Typ
Max
Min
Typ
Max
Amplifier to Amplifier Coupling
T
A
=25C,
-120
-120
-120
dB
f=1 Hz-20 kHz
(Input Referred)
SR
Slew Rate
V
S
=
15V, T
A
=25C
8
13
8
13
8
13
V/s
GBW
Gain-Bandwidth Product
V
S
=
15V, T
A
=25C
2.2
4
2.2
4
2.2
4
MHz
e
n
Equivalent Input Noise Voltage
T
A
=25C, R
S
=100
,
20
20
20
f=1000 Hz
i
n
Equivalent Input Noise Current
T
j
=25C, f=1000 Hz
0.01
0.01
0.01
THD
Total Harmonic Distortion
A
V
=+10, R
L
=10k,
V
O
=20 Vp-p,
BW=20 Hz-20 kHz
<
0.02
<
0.02
<
0.02
%
Note 2: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for which the device is func-
tional, but do not guarantee specific performance limits.
Note 3: Unless otherwise specified the absolute maximum negative input voltage is equal to the negative power supply voltage.
Note 4: 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 5: For operating at elevated temperature, these devices must be derated based on a thermal resistance of
jA
.
Note 6: The LF147 is available in the military temperature range -55C
T
A
125C, while the LF347B and the LF347 are available in the commercial temperature
range 0C
T
A
70C. Junction temperature can rise to T
j
max = 150C.
Note 7: Unless otherwise specified the specifications apply over the full temperature range and for V
S
=
20V for the LF147 and for V
S
=
15V for the LF347B/LF347.
V
OS
, I
B
, and I
OS
are measured at V
CM
=0.
Note 8: The input bias currents are junction leakage currents which approximately double for every 10C increase in the junction temperature, T
j
. Due to limited pro-
duction test time, the input bias currents measured are correlated to junction temperature. In normal operation the junction temperature rises above the ambient tem-
perature as a result of internal power dissipation, P
D
. T
j
=T
A
+
jA
P
D
where
jA
is the thermal resistance from junction to ambient. Use of a heat sink is recommended
if input bias current is to be kept to a minimum.
Note 9: Supply voltage rejection ratio is measured for both supply magnitudes increasing or decreasing simultaneously in accordance with common practice from
V
S
=
5V to
15V for the LF347 and LF347B and from V
S
=
20V to
5V for the LF147.
Note 10: Refer to RETS147X for LF147D and LF147J military specifications.
Note 11: Max. Power Dissipation is defined by the package characteristics. Operating the part near the Max. Power Dissipation may cause the part to operate out-
side guaranteed limits.
Note 12: Human body model, 1.5 k
in series with 100 pF.
LF147/LF347
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3
Typical Performance Characteristics
Input Bias Current
DS005647-14
Input Bias Current
DS005647-15
Supply Current
DS005647-16
Positive Common-Mode
Input Voltage Limit
DS005647-17
Negative Common-Mode
Input Voltage Limit
DS005647-18
Positive Current Limit
DS005647-19
Negative Current Limit
DS005647-20
Output Voltage Swing
DS005647-21
Output Voltage Swing
DS005647-22
LF147/LF347
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4
Typical Performance Characteristics
(Continued)
Gain Bandwidth
DS005647-23
Bode Plot
DS005647-24
Slew Rate
DS005647-25
Distortion vs Frequency
DS005647-26
Undistorted Output Voltage
Swing
DS005647-27
Open Loop Frequency
Response
DS005647-28
Common-Mode Rejection
Ratio
DS005647-29
Power Supply Rejection
Ratio
DS005647-30
Equivalent Input Noise
Voltage
DS005647-31
LF147/LF347
www.national.com
5
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