9

LT1112/LT1114

CC

HARA TERISTICS

A

TYPICALPERFOR

CE

FREQUENCY (kHz)

1

16

20

24

28

10

100

1000

LT1112/14 • TPC30

12

8

4

0

Large-Signal Transient Response

Small-Signal Transient Response

50

µs/DIV

2

µs/DIV

Undistorted Output Voltage

vs Frequency

INPUT:

±5.2V Sine Wave

LT1112 Output

OP-297 Output

S

APPLICATI

I FOR ATIO

The LT1112 dual and LT1114 quad in the plastic and

ceramic DIP packages are pin compatible to and directly

replace such precision op amps as the OP-200, OP-297,

AD706 duals and OP-400, OP-497, AD704 quads with

improved price/performance.

The LT1112 in the S8 surface mount package has the

standard pin configuration, i.e., the same configuration as

the plastic and ceramic DIP packages.

The LT1114 quad is offered in the narrow 16-pin surface

mount package. All competitors are in the wide 16-pin

package which occupies 1.8 times the area of the narrow

package. The wide package is also 1.8 times thicker than

the narrow package.

The inputs of the LT1112/1114 are protected with back-to-

back diodes. In the voltage follower configuration, when

the input is driven by a fast large-signal pulse (>1V), the

input protection diodes effectively short the output to the

input during slewing, and a current, limited only by the

output short-circuit protection, will flow through the

diodes.

The use of a feedback resistor is recommended because

this resistor keeps the current below the short-circuit limit,

resulting in faster recovery and settling of the output.

The input voltage of the LT1112/1114 should never exceed

the supply voltages by more than a diode drop. However,

the example below shows that as the input voltage exceeds

the common-mode range, the LT1112’s output clips

cleanly, without any glitches or phase reversal. The OP-

297 exhibits phase reversal. The photos also illustrate that

both the input and output ranges of the LT1112 are within