Datasheet
+
-
R
IN
51:
R
F
1.2k:
X1
-
+
R
OUT
51:
RG
1.2k:
CL
10pF
R
L
1k:
+
-
6.8PF
C2
100nF
R
IN
75:
R
G
1.2k:
R
F
1.2k:
100nF
C3
6.8PF
C4
X1
-
+
R
OUT
75:
C1
1 2 3 4 5 6 7 8 9 10
0
200
400
600
800
1000
1200
1400
R
F
(:)
GAIN (-V/V)
LMH6723, LMH6724, LMH6725
www.ti.com
SNOSA83H –AUGUST 2003–REVISED APRIL 2013
Figure 39. R
F
vs. Inverting Gain
ACTIVE FILTERS
When using any current feedback operational amplifier as an active filter it is necessary to be careful using
reactive components in the feedback loop. Reducing the feedback impedance, especially at higher frequencies,
will almost certainly cause stability problems. Likewise capacitance on the inverting input should be avoided. See
Application Notes OA-07 and OA-26 for more information on Active Filter applications for Current Feedback Op
Amps.
When using the LMH6723/LMH6724/LMH6725 as a low-pass filter the value of R
F
can be substantially reduced
from the value recommended in the R
F
vs. Gain charts. The benefit of reducing R
F
is increased gain at higher
frequencies, which improves attenuation in the stop band. Stability problems are avoided because in the stop
band additional device bandwidth is used to cancel the input signal rather than amplify it. The benefit of this
change depends on the particulars of the circuit design. With a high pass filter configuration reducing R
F
will
likely result in device instability and is not recommended.
Figure 40. Typical Application with Suggested Supply Bypassing
Figure 41. Decoupling Capacitive Loads
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Product Folder Links: LMH6723 LMH6724 LMH6725