why do we use active filter?

[liletian]

advantage of active filter

Hi Guys
what is the advantages of active filter? The only advantage I can think is active filter can give you, is there any other reasons for it?
Thanks,

 

[mabauti]

why do we use active filter

basically you can adjust gain

 

[dipnirvana]

why we use active filter

almost free from input and output impedance changes

 

[LvW]

Hi Guys
what is the advantages of active filter? The only advantage I can think is active filter can give you, is there any other reasons for it?
Thanks,

There are several adantages:

1.) Most important: No inductances, which are heavy, expensive, sensitive to electro-magnetic effects, not integrateable, not easy to tune, ....
2.) Filter design is easy, as you only need to caculate 2nd order stages, which can be cascaded to higher order filters (because of low output impedances)
3.) They can be tuned by voltages or currents
4.) They can provide gain
5.) Active filter topologies can be fully integrated (OTA-C or gm-C approaches)
6.) They are the basics to design S/C filters