LM118/LM218/LM318

Operational Amplifiers

General Description

The LM118 series are precision high speed operational am-

plifiers designed for applications requiring wide bandwidth

and high slew rate. They feature a factor of ten increase in

speed over general purpose devices without sacrificing DC

performance.

The LM118 series has internal unity gain frequency compen-

sation. This considerably simplifies its application since no

external components are necessary for operation. However,

unlike most internally compensated amplifiers, external fre-

quency compensation may be added for optimum perfor-

mance. For inverting applications, feedforward compensa-

tion will boost the slew rate to over 150V/µs and almost

double the bandwidth. Overcompensation can be used with

the amplifier for greater stability when maximum bandwidth

is not needed. Further, a single capacitor can be added to

reduce the 0.1% settling time to under 1 µs.

The high speed and fast settling time of these op amps make

them useful in A/D converters, oscillators, active filters,

sample and hold circuits, or general purpose amplifiers.

These devices are easy to apply and offer an order of

magnitude better AC performance than industry standards

such as the LM709.

The LM218 is identical to the LM118 except that the LM218

has its performance specified over a −25˚C to +85˚C tem-

perature range. The LM318 is specified from 0˚C to +70˚C.

Features

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15 MHz small signal bandwidth

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Guaranteed 50V/µs slew rate

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Maximum bias current of 250 nA

n

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Internal frequency compensation

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Input and output overload protected

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Pin compatible with general purpose op amps

Fast Voltage Follower

(Note 1)

00776613

Note 1: Do not hard-wire as voltage follower (R1

≥ 5kΩ)

August 2000

© 2004 National Semiconductor Corporation

DS007766

www.national.com