LF351N - STMicroelectronics

April 2008 Rev 2 1/14

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.

DIP8

(Plastic package)

SO-8

(Plastic micro package)

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)

www.st.com

Schematics LF351

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1 Schematics

Figure 1. Schematic diagram

Figure 2. Input offset voltage null circuit

Output

Non-inverting input

Inverting input

100

1.3k

30k

35k 35k 100

1.3k

8.2k

Offset Null1 Offset Null2

100

200

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

Iib Input bias current (1)

Tmin ≤ T

amb ≤ T

max

20 200

20 pA

Avd Large signal voltage gain (RL = 2kΩ, Vo = ±10V)

Tmin ≤ Tamb ≤ T

max

25 200 V/mV

SVR Supply voltage rejection ratio (RS = 10 kΩ)

Tmin ≤ T

amb ≤ T

max

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 86 dB

IOS Output short-circuit current

Tmin ≤ T

amb ≤ Tmax

10 40 60

60 mA

±Vopp

Output voltage swing

RL = 2kΩ

RL = 10kΩ

Tmin ≤ T

amb ≤ T

max

RL = 2kΩ

RL = 10kΩ

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.

------------

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

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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

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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

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4 Parameter measurement information

Figure 20. Voltage follower Figure 21. Gain-of-10 inverting amplifier

LF351 Typical application

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5 Typical application

Figure 22. Square wave oscillator (0.5 Hz)

Figure 23. High Q notch filter

Package information LF351

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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

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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

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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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