LF442.PDF

February 1995

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 X load) as the LM1458 and only

draw one tenth the supply current of the LM1458. In addi-

tion 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

design and internal trimming guarantees very low input off-

set 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

400 m A (max)

Y Low input bias current

50 pA (max)

Y Low input offset voltage

1 mV (max)

Y Low input offset voltage drift

10 m V/ § C (max)

Y High gain bandwidth

1 MHz

Y High slew rate

1 V/ m s

Y Low noise voltage for low power

35 nV/

Y Low input noise current

0.01 pA/

Y High input impedance

10 12 X

Y High gain V O e g 10V, R L e 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

Metal Can Package

TL/H/9155±2

TL/H/9155±1

Simplified Schematic

(/2

Dual

Top View

Note: Pin 4 connected to case

Order Number LF442AMH

or LF442MH/883

See NS Package Number H08A

Dual-In-Line Package

TL/H/9155±4

TL/H/9155±3

Top View

Order Number LF442ACN or LF442CN

See NS Package Number N08E

BI-FET II TM is a trademark of National Semiconductor Corporation.

C 1995 National Semiconductor Corporation

TL/H/9155

RRD-B30M115/Printed in U. S. A.

(/10 supply current of a LM1458

Absolute Maximum Ratings

If Military/Aerospace specified devices are required,

please contact the National Semiconductor Sales

Office/Distributors for availability and specifications.

(Note 9)

H Package

N Package

T j max

150 § C

115 § C

i JA (Typical)

(Note 3)

65 § C/W

114 § C/W

LF442A

LF442

(Note 4)

165 § C/W

152 § C/W

Supply Voltage

g 22V

g 18V

i JC (Typical) 21 § C/W

Operating Temperature (Note 4)

Differential Input Voltage g 38V

g 30V

(Note 4)

Input Voltage Range

g 19V

g 15V

Range

Storage

(Note 1)

Output Short Circuit

b 65 § C s T A s 150 § C b 65 § C s T A s 150 § C

Continuous Continuous

Temperature Range

Lead Temperature

Duration (Note 2)

260 § C

(Soldering, 10 sec.)

ESD Tolerance

Rating to be determined

DC Electrical Characteristics (Note 6)

Symbol

Parameter

Conditions

LF442A

LF442

Units

Min Typ Max Min Typ Max

V OS

Input Offset Voltage R S e 10 k X ,T A e 25 § C

0.5 1.0

1.0 5.0 mV

Over Temperature

7.5 mV

D V OS / D T Average TC of Input R S e 10 k X

m V/ § C

Offset Voltage

I OS

Input Offset Current V S e g 15V T j e 25 § C

(Notes 6 and 7)

T j e 70 § C

1.5

T j e 125 § C

I B

Input Bias Current

V S e g 15V T j e 25 § C

10 50

10 100 pA

(Notes 6 and 7)

T j e 70 § C

T j e 125 § C

R IN

Input Resistance

T j e 25 § C

10 12

A VOL

Large Signal Voltage V S e g 15V, V O e g 10V,

50 200

25 200

V/mV

Gain

R L e 10 k X ,T A e 25 § C

Over Temperature

25 200

15 200

V/mV

V O

Output Voltage Swing V S e g 15V, R L e 10 k X g 12 g 13

g 12 g 13

V CM

Input Common-Mode

g 16 a 18

g 11 a 14

Voltage Range

b 17

b 12

CMRR Common-Mode

R S s 10 k X

80 100

70 95

Rejection Ratio

PSRR Supply Voltage

(Note 8)

80 100

70 90

Rejection Ratio

I S

Supply Current

300 400

400 500 m A

AC Electrical Characteristics (Note 6)

Symbol

Parameter

Conditions

LF442A

LF442

Units

Min Typ Max Min Typ Max

Amplifier to Amplifier

T A e 25 § C, f e 1 Hz-20 kHz

b 120

Coupling

(Input Referred)

Slew Rate

V S e g 15V, T A e 25 § C

0.8

0.6

V/ m s

GBW Gain-Bandwidth Product V S e g 15V, T A e 25 § C

0.8

0.6

MHz

e n

Equivalent Input Noise T A e 25 § C, R S e 100 X ,

nV/

Voltage

f e 1 kHz

i n

Equivalent Input Noise T A e 25 § C, f e 1 kHz

0.01

pA/

Current

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: The value given is in 400 linear feet/min air flow.

Note 4: The value given is in static air.

Note 5: These devices are available in both the commercial temperature range 0 § C s T A s 70 § C and the military temperature range b 55 § C s T A s 125 § C. 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 ``H'' package only.

Note 6: Unless otherwise specified, the specifications apply over the full temperature range and for V S e g 20V for the LF442A and for V S e g 15V for the LF442.

V OS ,I B , and I OS are measured at V CM e 0.

Note 7: The input bias currents are junction leakage currents which approximately double for every 10 § C increase in the junction temperature, T j . Due to limited

production test time, the input bias currents measured are correlated to junction temperature. In normal operation the junction temperature rises above the ambient

temperature as a result of internal power dissipation, P D .T j e T A ai jA P D where i 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 8: Supply voltage rejection ratio is measured for both supply magnitudes increasing or decreasing simultaneously in accordance with common practice from

g 15V to g 5V for the LF442 and g 20V to g 5V for the LF442A.

Note 9: Refer to RETS442X for LF442MH military specifications.

Typical Performance Characteristics

Input Bias Current

Supply Current

Positive Common-Mode

Negative Common-Mode

Input Voltage Limit

Positive Current Limit

Negative Current Limit

Output Voltage Swing

TL/H/9155±5

Typical Performance Characteristics (Continued)

Gain Bandwidth

Bode Plot

Slew Rate

Undistorted Output Voltage

Open Loop Frequency

Distortion vs Frequency

Swing

Response

Common-Mode Rejection

Power Supply Rejection

Equivalent Input Noise

Ratio

Voltage

Open Loop Voltage Gain

Output Impedance

Inverter Settling Time

TL/H/9155±6

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