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difference between active and passive filters

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vasu

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For designing the band pass butterworth filter of 500kHz bandwidth and fL=200KHz and fH=800KHz which one is better solution?
 

IanP

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difference between active and passive filter

Active filters use amplifying elements, especially op amps, with resistors and capacitors in their feedback loops, to synthesize the desired filter characteristics. Active filters can have high input impedance, low output impedance, and virtually any arbitrary gain.
They are also usually easier to design than passive filters. Possibly their most important attribute is that they lack inductors, thereby reducing the problems
associated with those components.

"A Basic Introduction to Filters–Active, Passive, and Switched-Capacitor"
https://www.swarthmore.edu/NatSci/echeeve1/Ref/DataSheet/IntroToFilters.pdf

Regards,
IanP
 

zenisle

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difference between passive and active filters

if you can choose off chip method, that is better
 

vasu

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active passive filters difference

Thanks for reply,
In my application ie for 200KHz to 800KHz which solution is better.
Is active or passive?
 

IanP

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difference between passive and active filters

For resons quoted in my previous post I would go for active filters..

Regards,
IanP
 

vasu

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different between active and passive filter

Thanks Ian,

I am also going with active filter but while designing i found that with smaller Q factor the passband is less.
since our application is of higher frequency i am not getting flat response.
Can u suggest any artical which helps in selecting correct opamp for that.

with thanks
 

Kral

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difference between active passive filters

vasu,
If you go the active route, the circuit must have considerable (i.e. >100) loop gain at the highest frequency of interest , in your case 800KHz. Otherwise the actual response will differ considerably from the ideal response.
~
Some disadvantages of passive filters:
Hard to design high Q inductors.
Filter must be designed for specific source and load impedances.
Regards,
Kral
 

maejchi

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what are the major diferences between passive and active filters used in the electronic instrumentation??can anyone please help me...
 

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