+

-

51:

1.2k:

X1

-

+

51:

RG

1.2k:

CL

10pF

1k:

+

-

6.8PF

C2

100nF

75:

1.2k:

1.2k:

100nF

C3

6.8PF

C4

X1

-

+

75:

C1

LMH6723, LMH6724

SNOSA83I – AUGUST 2003 – REVISED AUGUST 2014

www.ti.com

7.5 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.

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

likely result in device instability and is not recommended.

Figure 34. Typical Application with Suggested Supply Bypassing

Figure 35. Decoupling Capacitive Loads

7.6 Driving Capacitive Loads

Capacitive output loading applications will benefit from the use of a series output resistor as shown in Figure 35.

mitigating capacitive loads. The values suggested in the charts are selected for .5 dB or less of peaking in the

frequency response. This gives a good compromise between settling time and bandwidth. For applications where

slightly from the recommended values.

There will be amplitude lost in the series resistor unless the gain is adjusted to compensate; this effect is most

16

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