A Comparison of Passive Filters and Active Filters

The Advantages of Each Filter Type:

PASSIVE	ACTIVE
no power supply required can handle large currents and high voltages very reliable least number of components for given filter noise arises from resistances only no bandwidth limitation	no inductors easier to design high Zin, low Zout for minimal loading can produce high gains generally easier to tune small in size and weight

PASSIVE	ACTIVE
inductors large for lower frequencies some inductors (non-toroidal) may require shielding limited standard sizes, often requiring variable inductors and therefore tuning low tolerance inductors (1-2%) very expensive must be designed with consideration to input and output loading generally not amenable to miniaturization no power gain possible no voltage gain	power supply required susceptible to intermodulation, oscillations susceptible to parasitics from DC output offset voltage and input bias currents op amp gain bandwidth constrained op amp slew rate constrained can require many components