LF442
Dual Low Power JFET Input Operational Amplifier
General Description
The LF442 dual low power operational amplifiers provide
many of the same AC characteristics as the industry stan-
dard LM1458 while greatly improving the DC characteristics
of the LM1458. The amplifiers have the same bandwidth,
slew rate, and gain (10 k
load) as the LM1458 and only
draw one tenth the supply current of the LM1458. In addition
the well matched high voltage JFET input devices of the
LF442 reduce the input bias and offset currents by a factor of
10,000 over the LM1458. A combination of careful layout de-
sign and internal trimming guarantees very low input offset
voltage and voltage drift. The LF442 also has a very low
equivalent input noise voltage for a low power amplifier.
The LF442 is pin compatible with the LM1458 allowing an
immediate 10 times reduction in power drain in many appli-
cations. The LF442 should be used where low power dissi-
pation and good electrical characteristics are the major con-
siderations.
Features
n
1/10 supply current of a LM1458:
400 A (max)
n
Low input bias current:
50 pA (max)
n
Low input offset voltage:
1 mV (max)
n
Low input offset voltage drift:
10 V/C (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 V
O
=
10V, R
L
= 10k: 50k (min)
Typical Connection
Ordering Information
LF442XYZ
X indicates electrical grade
Y indicates temperature range
"M" for military
"C" for commercial
Z indicates package type
"H" or "N"
Connection Diagrams
BI-FET II
TM
is a trademark of National Semiconductor Corporation.
DS009155-1
Metal Can Package
DS009155-2
Pin 4 connected to case
Top View
Order Number LF442AMH or LF442MH
or LF442MH/883
See NS Package Number H08A
Dual-In-Line Package
DS009155-4
Top View
Order Number LF442ACN or LF442CN
See NS Package Number N08E
April 1999
LF442
Dual
Low
Power
JFET
Input
Operational
Amplifier
1999 National Semiconductor Corporation
DS009155
www.national.com
Absolute Maximum Ratings
(Note 1)
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
LF442A
LF442
Supply Voltage
22V
18V
Differential Input Voltage
38V
30V
Input Voltage Range
19V
15V
(Note 2)
Output Short Circuit
Continuous
Continuous
Duration (Note 3)
H Package
N Package
T
j
max
150C
115C
H Package
N Package
JA
(Typical)
(Note 4)
(Note 5)
65C/W
165C/W
114C/W
152C/W
JC
(Typical)
21C/W
Operating Temperature
(Note 5)
(Note 5)
Range
Storage
-65C
T
A
150C -65C
T
A
150C
Temperature Range
Lead Temperature
260C
260C
(Soldering, 10 sec.)
ESD Tolerance
Rating to be determined
DC Electrical Characteristics
(Note 7)
Symbol
Parameter
Conditions
LF442A
LF442
Units
Min
Typ
Max
Min
Typ
Max
V
OS
Input Offset Voltage
R
S
= 10 k
, T
A
= 25C
0.5
1.0
1.0
5.0
mV
Over Temperature
7.5
mV
V
OS
/
T
Average TC of Input
R
S
= 10 k
7
10
7
V/C
Offset Voltage
I
OS
Input Offset Current
V
S
=
15V
T
j
= 25C
5
25
5
50
pA
(Notes 7, 8)
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 7, 8)
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
200
25
200
V/mV
Gain
R
L
= 10 k
, T
A
= 25C
Over Temperature
25
200
15
200
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 9)
80
100
70
90
dB
Rejection Ratio
I
S
Supply Current
300
400
400
500
A
AC Electrical Characteristics
(Note 7)
Symbol
Parameter
Conditions
LF442A
LF442
Units
Min
Typ
Max
Min
Typ
Max
Amplifier to Amplifier
T
A
= 25C, f = 1 Hz-20 kHz
-120
-120
dB
Coupling
(Input Referred)
SR
Slew Rate
V
S
=
15V, T
A
= 25C
0.8
1
0.6
1
V/s
GBW
Gain-Bandwidth Product
V
S
=
15V, T
A
= 25C
0.8
1
0.6
1
MHz
e
n
Equivalent Input Noise
T
A
= 25C, R
S
= 100
,
35
35
Voltage
f = 1 kHz
i
n
Equivalent Input Noise
T
A
= 25C, f = 1 kHz
0.01
0.01
Current
www.national.com
2
AC Electrical Characteristics
(Note 7) (Continued)
Note 1: "Absolute Maximum Ratings" indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for which the device is
functional, but do not guarantee specific performance limits.
Note 2: Unless otherwise specified the absolute maximum negative input voltage is equal to the negative power supply voltage.
Note 3: 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 4: The value given is in 400 linear feet/min air flow.
Note 5: The value given is in static air.
Note 6: These devices are available in both the commercial temperature range 0C
T
A
70C and the military temperature range -55C
T
A
125C. The tem-
perature 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" indi-
cates the military temperature range. The military temperature range is available in "H" package only.
Note 7: Unless otherwise specified, the specifications apply over the full temperature range and for V
S
=
20V for the LF442A and for V
S
=
15V for the LF442.
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
15V to
5V for the LF442 and
20V to
5V for the LF442A.
Note 10: Refer to RETS442X for LF442MH military specifications.
Typical Performance Characteristics
Input Bias Current
DS009155-17
Input Bias Current
DS009155-18
Supply Current
DS009155-19
Positive Common-Mode
Input Voltage Limit
DS009155-20
Negative Common-Mode
Input Voltage Limit
DS009155-21
Positive Current Limit
DS009155-22
www.national.com
3
Typical Performance Characteristics
(Continued)
Negative Current Limit
DS009155-23
Output Voltage Swing
DS009155-24
Output Voltage Swing
DS009155-25
Gain Bandwidth
DS009155-26
Bode Plot
DS009155-27
Slew Rate
DS009155-28
Distortion vs Frequency
DS009155-29
Undistorted Output Voltage
Swing
DS009155-30
Open Loop Frequency
Response
DS009155-31
www.national.com
4
Typical Performance Characteristics
(Continued)
Pulse Response
R
L
= 10 k
, C
L
= 10 pF
Common-Mode Rejection
Ratio
DS009155-32
Power Supply Rejection
Ratio
DS009155-33
Equivalent Input Noise
Voltage
DS009155-34
Open Loop Voltage Gain
DS009155-35
Output Impedance
DS009155-36
Inverter Settling Time
DS009155-37
Small Signal Inverting
DS009155-7
Small Signal Non-Inverting
DS009155-8
www.national.com
5
PDF 
ZIP