April 2008 Rev 2 1/14
14
LF351
Wide bandwidth single JFET operational amplifiers
Features
Internally adjustable input offset voltage
Low power consumption
Wide common-mode (up to VCC+) and
differential voltage range
Low input bias and of fset current
Output short-circuit protection
High input impedance JFET input stage
Internal frequency compensation
Latch up free operation
High slew rate 16 V/µs (typical)
Description
These circuits are high speed JFET input single
operationa l amplifiers incorporating w ell matched,
high voltage JFET and bi polar transistors in a
monolithic integr ated circuit.
The devices feat ure high slew rates, low input
bias and offset curr ents, and low offset voltage
temperature coe ff icie nt.
N
DIP8
(Plastic package)
D
SO-8
(Plastic micro package)
1
2
3
4
8
6
5
7
1 - Offset null 1
2 - Inverting input
3 - Non-inverting input
4 - VCC-
5 - Offset null 2
6 - Output
7 - VCC+
8 - N.C.
Pin connections
(top view)
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Schematics LF351
2/14
1 Schematics
Figure 1. Schematic diagram
Figure 2. Input offset voltage null circuit
Output
Non-inverting input
Inverting input
V
CC
V
CC
100
W
1.3k
30k
35k 35k 100
W
1.3k
8.2k
Offset Null1 Offset Null2
100
W
200
W
LF351 Absolute maximum ratings and operating conditions
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2 Absolute maximum ratings and operating conditions
Table 1. Absolute maximum ratings
Symbol Parameter Value Unit
VCC Supply voltage(1) ±18 V
ViInput voltage(2) ±15 V
Vid Differential input voltage(3) ±30 V
Rthja
Ther mal resistance junction to ambient(4)
SO-8
DIP8 125
85 °C/W
Rthjc
Thermal resistance junction to case(4)
SO-8
DIP8 40
41 °C/W
Output short-circuit duration(5) Infinite
Tstg Storage temperature range -65 to +150 °C
ESD
HBM: human body model(6) 500 V
MM: mach ine model(7) 200 V
CDM: charged device model(8) 1.5 kV
1. All voltage values, except differential voltage, are with respect to the zero reference level (ground) of the supply voltages
where the zero reference level is the midpoint between VCC+ and V CC-.
2. The magnitude of the input voltage must never exceed the magnitude of the supply voltage or 15 volts, whichever is less.
3. Differential voltages are the non-inverting input terminal with respect to the inverting input terminal.
4. Short-circuits can cause excessive heating and destructive dissipation. Values are typical.
5. The output may be shorted to ground or to either supply. Temperature and/or supply voltages must be limited to ensure
that the dissipation rating is not exceeded
6. Human body model: A 100 pF capacitor is charged to the specified voltage, then discharged through a 1.5 kΩ resistor
between two pins of the device. This is done for all couples of connected pin combinations while the other pins are floating.
7. Machine model: A 200 pF capacitor is charged to the specified voltage, then discharged directly between two pins of the
device with no external series resistor (internal resistor < 5 Ω). This is done for all couples of connected pin combinations
while the other pins are floating.
8. Charged device model: all pins and the package are charged together to the specified voltage and then discharged directly
to the ground through only one pin. This is done for all pins.
Table 2. Operating conditions
Symbol Parameter LF151 LF251 LF351 Unit
VCC Supply voltage 6 to 32 V
Toper Operating free-air temp erature range -55 to +125 -40 to +105 0 to +70 °C
Electrical characteristics LF351
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3 Electrical characteristics
Table 3. Electrical characteristics at VCC = ±15 V, Tamb = +25°C (unless otherwise specified)
Symbol Parameter Min. Typ. Max. Unit
Vio Input offset voltage (Rs = 10kΩ)
Tmin T
amb T
max
310
13 mV
DVio Input offset voltage drift 10 µV/°C
Iio Input offset current (1)
Tmin T
amb T
max
5 100
4pA
nA
Iib Input bias current (1)
Tmin T
amb T
max
20 200
20 pA
nA
Avd Large signal voltage gain (RL = 2kΩ, Vo = ±10V)
Tmin Tamb T
max
50
25 200 V/mV
SVR Supply voltage rejection ratio (RS = 10 kΩ)
Tmin T
amb T
max
80
80 86 dB
ICC Supply current, no load
Tmin T
amb T
max
1.4 3.4
3.4 mA
Vicm Input common mode voltage range ±11 +15
-12 V
CMR Common mode rejection ratio (RS = 10kΩ)
Tmin T
amb T
max
70
70 86 dB
IOS Output short-circuit current
Tmin T
amb Tmax
10
10 40 60
60 mA
±Vopp
Output voltage swing
RL = 2kΩ
RL = 10kΩ
Tmin T
amb T
max
RL = 2kΩ
RL = 10kΩ
10
12
10
12
12
13.5 V
SR Slew rate, Vi = 10V, RL = 2kΩ, CL = 100pF, unity gain 12 16 V/µs
trRise time, Vi = 20mV, RL = 2kΩ, CL = 100pF, unity gain 0.1 µs
Kov Overshoot, Vi = 20mV, RL = 2kΩ, CL = 100pF, unity gain 10 %
GBP Gain bandwidth product, f = 100kHz, Vin = 10mV, RL = 2kΩ, CL = 100pF 2.5 4 MHz
RiInput resistance 1012 Ω
THD Total harmonic distortion
f= 1kHz, Av= 20dB, RL= 2kΩ, CL=100pF, Vo=2V
pp 0.01 %
enEquivalent input noise voltage
RS = 100Ω, f = 1KHz 15
m Phase margin 45 Degrees
1. The input bias currents are junction leakage currents which approximately double for every 10°C increase in the junction
temperature.
nV
Hz
------------
LF351 Electr ical characteristics
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Figure 3. Maximum pea k-to-peak output
voltage versus frequency Figure 4. Maximum peak-to-peak output
voltage versus frequency
Figure 5. Maximum pea k-to-peak output
voltage versus frequency Figure 6. Maximum peak-to-peak output
voltage versus free air temp.
Figure 7. Maximum pea k-to-peak output
voltage versus load resistance Figure 8. Ma ximum peak-to-peak ou tput
voltage versus supply volta ge
Electrical characteristics LF351
6/14
Figure 9. Input bias current versus free air
temperature Figure 10. Large sign al differential voltage
amplification versus free air temp.
Figure 11. Large signal differential volta ge
amplification and phase shift
versus frequency
Figure 12. Total power dissipation versus free
air temperature
Figure 13. Supply curr ent per amplifier ver sus
free air temperature Figure 14. Supply current per amplifi er ver sus
supply voltage
LF351 Electr ical characteristics
7/14
Figure 15. Common mode rejection ratio
versus free air temperature Figure 16. Voltage follower large signal pulse
response
Figure 17. Output voltage versus elapsed time Figure 18. Equivalen t input noise voltage
versus frequency
Figure 19. Total harmonic distortion versus
frequency
Parameter measurement information LF351
8/14
4 Parameter measurement information
Figure 20. Voltage follower Figure 21. Gain-of-10 inverting amplifier
LF351 Typical application
9/14
5 Typical application
Figure 22. Square wave oscillator (0.5 Hz)
Figure 23. High Q notch filter
Package information LF351
10/14
6 Package information
In order to meet environmental requirements, STMicroelectronics offers these devices in
ECOPACK® pa ckages. These packages have a lead-fre e second level interconnect. The
category of second level interconnect is marked on the pa ckage and on the inner box label,
in compliance with JEDEC Standard JESD97. The maximum ratings related to soldering
conditions are also marked on the inner box label. ECOPA CK is an STMicroele ctronics
tradema rk. ECOPA CK specifications are available at: www.st.com.
LF351 Package information
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6.1 DIP8 pack age information
Figure 24. DIP8 package mechanical drawing
Table 4. DIP8 package mechanical data
Ref.
Dimensions
Millimeters Inches
Min. Typ. Max. Min. Typ. Max.
A5.330.210
A1 0.38 0.015
A2 2.92 3.30 4.95 0.115 0.130 0.195
b 0.36 0.46 0.56 0.014 0.018 0.022
b2 1.14 1.52 1.78 0.045 0.060 0.070
c 0.20 0.25 0.36 0.008 0.010 0.014
D 9.02 9.27 10.16 0.355 0.365 0.400
E 7.62 7.87 8.26 0.300 0.310 0.325
E1 6.10 6.35 7.11 0.240 0.250 0.280
e 2.54 0.100
eA 7.62 0.300
eB 10.92 0.430
L 2.92 3.30 3.81 0.115 0.130 0.150
Package information LF351
12/14
6.2 SO-8 package information
Figure 25. SO-8 package mechanical dra wing
Table 5. SO-8 package mechanical data
Ref.
Dimensions
Millimeters Inches
Min. Typ. Max. Min. Typ. Max.
A1.750.069
A1 0.10 0.25 0.004 0.010
A2 1.25 0.049
b 0.28 0.48 0.011 0.019
c 0.17 0.23 0.007 0.010
D 4.80 4.90 5.00 0.189 0.193 0.197
E 5.80 6.00 6.20 0.228 0.236 0.244
E1 3.80 3.90 4.00 0.150 0.154 0.157
e 1.27 0.050
h 0.25 0.50 0.010 0.020
L 0.40 1.27 0.016 0.050
k1°8°1°8°
ccc 0.10 0.004
LF351 Ordering information
13/14
7 Ordering information
8 Revision history
Table 6. Order codes
Order code Temperature
range Package Packing Marking
LF151N -55°C, +125°C DIP8 Tape LF151N
LF151D
LF151DT SO-8 Tape or
Tape & reel 151
LF251N -40°C, +105°C DIP8 Tape LF251N
LF251D
LF251DT SO-8 Tape or
Tape & reel 251
LF351N 0°C, +70°C DIP8 Tape LF351N
LF351D
LF351DT SO-8 Tape or
Tape & reel 351
Table 7. Document revision history
Date Revision Changes
17-May-2001 1 Initial release.
28-April-2008 2 Up dated document format.
LF351
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