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LF155, LF156, LF256, LF257

LF355, LF356, LF357

SNOSBH0D – MAY 2000 – REVISED NOVEMBER 2015

LFx5x JFET Input Operational Amplifiers

1 Features

2 Applications

1

•

Advantages

•

Precision High-Speed Integrators

•

Fast D/A and A/D Converters

–

Replace Expensive Hybrid and Module FET

Op Amps

•

High Impedance Buffers

–

Rugged JFETs Allow Blow-Out Free Handling

•

Wideband, Low Noise, Low Drift Amplifiers

Compared With MOSFET Input Devices

•

Logarithmic Amplifiers

–

Excellent for Low Noise Applications Using

•

Photocell Amplifiers

Either High or Low Source Impedance—Very

•

Sample and Hold Circuits

Low 1/f Corner

–

Offset Adjust Does Not Degrade Drift or

3 Description

Common-Mode Rejection as in Most

The LFx5x devices are the first monolithic JFET input

Monolithic Amplifiers

operational amplifiers to incorporate well-matched,

–

New Output Stage Allows Use of Large

high-voltage JFETs on the same chip with standard

bipolar transistors (BI-FET™ Technology). These

Capacitive Loads (5,000 pF) Without Stability

amplifiers

feature

low

input

bias

and

offset

Problems

currents/low offset voltage and offset voltage drift,

–

Internal Compensation and Large Differential

coupled with offset adjust, which does not degrade

Input Voltage Capability

drift or common-mode rejection. The devices are also

•

Common Features

designed

for

high

slew

rate,

wide

bandwidth,

extremely fast settling time, low voltage and current

–

Low Input Bias Current: 30 pA

noise and a low 1/f noise corner.

–

Low Input Offset Current: 3 pA

–

High Input Impedance: 1012

Ω

Device Information(1)

–

Low Input Noise Current: 0.01 pA/

√Hz

PART NUMBER

PACKAGE

BODY SIZE (NOM)

–

High Common-Mode Rejection Ratio: 100 dB

SOIC (8)

4.90 mm × 3.91 mm

LFx5x

TO-CAN (8)

9.08 mm × 9.08 mm

–

Large DC Voltage Gain: 106 dB

PDIP (8)

9.81 mm × 6.35 mm

•

Uncommon Features

(1) For all available packages, see the orderable addendum at

–

Extremely Fast Settling Time to 0.01%:

the end of the data sheet.

–

4

μs for the LFx55 devices

–

1.5

μs for the LFx56

Simplified Schematic

–

1.5

μs for the LFx57 (AV = 5)

–

Fast Slew Rate:

–

5 V/µs for the LFx55

–

12 V/µs for the LFx56

–

50 V/µs for the LFx57 (AV = 5)

–

Wide Gain Bandwidth:

–

2.5 MHz for the LFx55 devices

–

5 MHz for the LFx56

–

20 MHz for the LFx57 (AV = 5)

–

Low Input Noise Voltage:

–

20 nV/

√Hz for the LFx55

3 pF in LF357 series

–

12 nV/

√Hz for the LFx56

–

12 nV/

√Hz for the LFx57 (AV = 5)

1

An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,

intellectual property matters and other important disclaimers. PRODUCTION DATA.