Datasheet

LT1991
9
1991fh
TYPICAL PERFORMANCE CHARACTERISTICS
P1 (Pin 1): Noninverting Gain-of-1 input. Connects a 450k
internal resistor to the op amp’s noninverting input.
P3 (Pin 2): Noninverting Gain-of-3 input. Connects a 150k
internal resistor to the op amp’s noninverting input.
P9 (Pin 3): Noninverting Gain-of-9 input. Connects a 50k
internal resistor to the op amp’s noninverting input.
V
EE
(Pin 4): Negative Power Supply. Can be either ground
(in single supply applications), or a negative voltage (in
split supply applications).
REF (Pin 5): Reference Input. Sets the output level when
difference between inputs is zero. Connects a 450k internal
resistor to the op amp’s noninverting input.
OUT (Pin 6): Output. V
OUT
= V
REF
+ 1 • (V
P1
– V
M1
) + 3 •
(V
P3
– V
M3
) + 9 • (V
P9
– V
M9
).
V
CC
(Pin 7): Positive Power Supply. Can be anything from
2.7V to 36V above the V
EE
voltage.
M9 (Pin 8): Inverting Gain-of-9 input. Connects a 50k
internal resistor to the op amp’s inverting input.
M3 (Pin
9): Inverting Gain-of-3 input. Connects a 150k
internal resistor to the op amp’s inverting input.
M1 (Pin 10): Inverting Gain-of-1 input. Connects a 450k
internal resistor to the op amp’s inverting input.
Exposed Pad: Must be soldered to PCB.
(Difference Amplifier Configuration)
50mV/DIV
5µs/DIV
GAIN = 1
1991 G18
50mV/DIV
5µs/DIV
1991 G19
GAIN = 3
50mV/DIV
5µs/DIV
GAIN = 9
1991 G20
Small Signal Transient Response Small Signal Transient Response Small Signal Transient Response
LT1991
1991 BD
9 8
2 3 4 5
7 610
1
M1 M3 M9
P1 P3 P9
V
CC
V
EE
OUT
REF
50k
50k
150k
150k
450k
450k
450k
450k
INM
INP
OUT
4pF
4pF
PIN FUNCTIONS
BLOCK DIAGRAM