LT1991 Linear Technology, LT1991 Datasheet - Page 9

• Manufacturer Part Number: LT1991
• Description: Precision / 100uA Gain Selectable Amplifier
• Manufacturer: Linear Technology

TYPICAL PERFORMANCE CHARACTERISTICS
PIN FUNCTIONS
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.
internal resistor to the op amp’s noninverting input.
V
(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.
BLOCK DIAGRAM
50mV/DIV
P9 (Pin 3): Noninverting Gain-of-9 input. Connects a 50k
EE
(Pin 4): Negative Power Supply. Can be either ground
Small Signal Transient Response
GAIN = 1
5μs/DIV
(Difference Amplifi er Confi guration)
1991 G18
50mV/DIV
M1
P1
10
1
M3
P3
Small Signal Transient Response
9
2
GAIN = 3
M9
P9
8
3
450k
450k
150k
150k
50k
50k
5μs/DIV
OUT (Pin 6): Output. V
(V
V
2.7V to 36V above the V
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.
CC
P3
INM
INP
4pF
(Pin 7): Positive Power Supply. Can be anything from
– V
V
V
7
4
CC
EE
OUT
M3
450k
4pF
450k
) + 9 • (V
LT1991
1991 G19
OUT
REF
6
5
1991 BD
50mV/DIV
P9
OUT
– V
EE
Small Signal Transient Response
M9
voltage.
= V
GAIN = 9
).
REF
www.DataSheet4U.com
+ 1 • (V
5μs/DIV
P1
LT1991
– V
M1
) + 3 •
1991 G20
1991fg
9