Datasheet

LT1996
14
1996f
Table 3. Configuring the M Pins for Simple Inverting Gains
M81, M27, M9 Connection
Gain M81 M27 M9
–0.083 Output Output Drive
–0.110 Output Float Drive
–0.297 Output Drive Output
–0.321 Float Output Drive
–0.329 Output Drive Float
–0.439 Output Drive Drive
–2.19 Drive Output Output
–2.7 Float Drive Output
–2.89 Drive Output Float
–3.21 Drive Output Drive
–8.1 Drive Float Output
–9 Float Float Drive
–10.8 Drive Drive Output
–27 Float Drive Float
–36 Float Drive Drive
–81 Drive Float Float
–90 Drive Float Drive
–108 Drive Drive Float
–117 Drive Drive Drive
Inverting Configuration
The inverting amplifier, shown in Figure 8, is another
classical op amp configuration. The circuit is actually
identical to the noninverting amplifier of Figure 4, except
that V
IN
and GND have been swapped. The list of available
gains is shown in Table 3, and some of the circuits are
shown in Figure 9. Noise gain is 1+|Gain|, as is the usual
case for inverting amplifiers. Again, for the best DC perfor-
mance, match the source impedance seen by the op amp
inputs.
4pF
4pF
–
+
R
F
R
G
V
IN
V
IN
(DRIVE)
V
OUT
V
OUT
V
OUT
= GAIN • V
IN
GAIN = – R
F
/R
G
–
+
1996 F08
450k
450k
8
6
5
9
10
1
2
3
LT1996
CLASSICAL INVERTING OP AMP CONFIGURATION.
YOU PROVIDE THE RESISTORS.
CLASSICAL INVERTING OP AMP CONFIGURATION IMPLEMENTED
WITH LT1991. R
F
= 45k, R
G
= 5.55k, GAIN = –8.1.
GAIN IS ACHIEVED BY GROUNDING, FLOATING OR FEEDING BACK
THE AVAILABLE RESISTORS TO ARRIVE AT DESIRED R
F
AND R
G
.
WE PROVIDE YOU WITH <0.1% RESISTORS.
450k/81
450k/27
450k/9
450k/81
450k/27
450k/9
4pF
4pF
Figure 8. The LT1996 as a Classical Inverting Op Amp. Note the
Circuit Is Identical to the Noninverting Amplifier, Except that V
IN
and Ground Have Been Swapped
APPLICATIO S I FOR ATIO
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