LT1112 Datasheet, PDF (9/12 Pages) Linear Technology – Dual/Quad Low Power Precision, Picoamp Input Op Amps

LT1112/LT1114
TYPICAL PERFOR A CE CHARACTERISTICS
Small-Signal Transient Response
Large-Signal Transient Response
A_V = +1
C_L = 500pF
V_S = ±15V
2µs/DIV
A_V = +1
R_F = 10k
C_F = 100pF
V_S = ±15V
50µs/DIV
Undistorted Output Voltage
vs Frequency
28
24
V_S = ±15V
20
T_A = 25°C
R_L = 10k
16
12
8
V_S = ±5V
4
0
1
10
100
1000
FREQUENCY (kHz)
LT1112/14 • TPC30
APPLICATI S 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
Voltage Follower with Input Exceeding the Common-Mode Range (V_S = ±5V)
INPUT: ±5.2V Sine Wave
LT1112 Output
OP-297 Output
9