LF444
Quad Low Power JFET Input Operational Amplifier
General Description
The LF444 quad low power operational amplifier provides
many of the same AC characteristics as the industry stan-
dard LM148 while greatly improving the DC characteristics
of the LM148. The amplifier has the same bandwidth, slew
rate, and gain (10 k
load) as the LM148 and only draws
one fourth the supply current of the LM148. In addition the
well matched high voltage JFET input devices of the LF444
reduce the input bias and offset currents by a factor of
10,000 over the LM148. The LF444 also has a very low
equivalent input noise voltage for a low power amplifier.
The LF444 is pin compatible with the LM148 allowing an im-
mediate 4 times reduction in power drain in many applica-
tions. The LF444 should be used wherever low power dissi-
pation and good electrical characteristics are the major
considerations.
Features
n
1
/
4
supply current of a LM148:
200 A/Amplifier (max)
n
Low input bias current:
50 pA (max)
n
High gain bandwidth:
1 MHz
n
High slew rate:
1 V/s
n
Low noise voltage for low power
n
Low input noise current
n
High input impedance:
10
12
n
High gain:
50k (min)
Simplified Schematic
Ordering Information
LF444XYZ
X indicates electrical grade
Y indicates temperature range
"M" for military, "C" for commercial
Z indicates package type "D", "M" or "N"
Connection Diagram
BI-FET
TM
and BI-FET II
TM
are trademarks of National Semiconductor Corporation.
1/4 Quad
DS009156-1
Dual-In-Line Package
DS009156-2
Top View
Order Number LF444CM, LF444CMX,
LF444ACN, LF 444CN or LF444MD/883
See NS Package Number D14E, M14A or N14A
August 2000
LF444
Quad
Low
Power
JFET
Input
Operational
Amplifier
2000 National Semiconductor Corporation
DS009156
www.national.com
Absolute Maximum Ratings
(Note 11)
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
LF444A
LF444
Supply Voltage
22V
18V
Differential Input Voltage
38V
30V
Input Voltage Range
19V
15V
(Note 1)
Output Short Circuit
Continuous
Continuous
Duration (Note 2)
D Package
N, M Packages
Power Dissipation
900 mW
670 mW
(Notes 3, 9)
T
j
max
150C
115C
jA
(Typical)
100C/W
85C/W
LF444A/LF444
Operating Temperature Range
(Note 4)
Storage Temperature Range
-65C
T
A
150C
ESD Tolerance (Note 10)
Rating to
be determined
Soldering Information
Dual-In-Line Packages
(Soldering, 10 sec.)
260C
Small Outline Package
Vapor Phase (60 sec.)
215C
Infrared (15 sec.)
220C
See AN-450 "Surface Mounting Methods and Their Effect on
Product Reliability" for other methods of soldering surface
mount devices.
DC Electrical Characteristics
(Note 5)
Symbol
Parameter
Conditions
LF444A
LF444
Units
Min
Typ
Max
Min
Typ
Max
V
OS
Input Offset Voltage
R
S
= 10k, T
A
= 25C
2
5
3
10
mV
0C
T
A
+70C
6.5
12
mV
-55C
T
A
+125C
8
mV
V
OS
/
T
Average TC of Input
R
S
= 10 k
10
10
V/C
Offset Voltage
I
OS
Input Offset Current
V
S
=
15V
T
j
= 25C
5
25
5
50
pA
(Notes 5, 6)
T
j
= 70C
1.5
1.5
nA
T
j
= 125C
10
nA
I
B
Input Bias Current
V
S
=
15V
T
j
= 25C
10
50
10
100
pA
(Notes 5, 6)
T
j
= 70C
3
3
nA
T
j
= 125C
20
nA
R
IN
Input Resistance
T
j
= 25C
10
12
10
12
A
VOL
Large Signal Voltage
V
S
=
15V, V
O
=
10V
50
100
25
100
V/mV
Gain
R
L
= 10 k
, T
A
= 25C
Over Temperature
25
15
V/mV
V
O
Output Voltage Swing
V
S
=
15V, R
L
= 10 k
12
13
12
13
V
V
CM
Input Common-Mode
16
+18
11
+14
V
Voltage Range
-17
-12
V
CMRR
Common-Mode
R
S
10 k
80
100
70
95
dB
Rejection Ratio
PSRR
Supply Voltage
(Note 7)
80
100
70
90
dB
Rejection Ratio
I
S
Supply Current
0.6
0.8
0.6
1.0
mA
LF444
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2
AC Electrical Characteristics
(Note 5)
Symbol
Parameter
Conditions
LF444A
LF444
Units
Min
Typ
Max
Min
Typ
Max
Amplifier-to-Amplifier
-120
-120
dB
Coupling
SR
Slew Rate
V
S
=
15V, T
A
= 25C
1
1
V/s
GBW
Gain-Bandwidth Product
V
S
=
15V, T
A
= 25C
1
1
MHz
e
n
Equivalent Input Noise Voltage
T
A
= 25C, R
S
= 100
,
35
35
f = 1 kHz
i
n
Equivalent Input Noise Current
T
A
= 25C, f = 1 kHz
0.01
0.01
Note 1: Unless otherwise specified the absolute maximum negative input voltage is equal to the negative power supply voltage.
Note 2: 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 3: For operating at elevated temperature, these devices must be derated based on a thermal resistance of
jA
.
Note 4: The LF444A is available in both the commercial temperature range 0C
T
A
70C and the military temperature range -55C
T
A
125C. The LF444 is
available in the commercial temperature range only. The temperature range is designated by the position just before the package type in the device number. A "C"
indicates the commercial temperature range and an "M" indicates the military temperature range. The military temperature range is available in "D" package only.
Note 5: Unless otherwise specified the specifications apply over the full temperature range and for V
S
=
20V for the LF444A and for V
S
=
15V for the LF444. V
OS
,
I
B
, and I
OS
are measured at V
CM
= 0.
Note 6: 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 7: Supply voltage rejection ratio is measured for both supply magnitudes increasing or decreasing simultaneously in accordance with common practice from
15V to
5V for the LF444 and from
20V to
5V for the LF444A.
Note 8: Refer to RETS444X for LF444MD military specifications.
Note 9: Max. Power Dissipation is defined by the package characteristics. Operating the part near the Max. Power Dissipation may cause the part to operate outside
guaranteed limits.
Note 10: Human body model, 1.5 k
in series with 100 pF.
Note 11: 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. Electrical Characteristics state DC and AC electrical specifications under particular test conditions which guar-
antee specific performance limits. This assumes that the device is within the Operating Ratings. Specifications are not guaranteed for parameters where no limit is
given, however, the typical value is a good indication of device performance.
Typical Performance Characteristics
Input Bias Current
DS009156-12
Input Bias Current
DS009156-13
LF444
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