I've only worked with series resistor-capacitor filters before, so I'm not very clear about the operation of parallel resistor-capacitors filters. Can somebody explain to me what are the differences between them and series resistor-capacitor circuits in terms of operation? Any help will be much appreciated.

  • \$\begingroup\$ My opinion is just google it before you post the questions here. This will improve your question and will get good answers. \$\endgroup\$ – Gouse Shaik Oct 28 '11 at 7:36
  • \$\begingroup\$ @Gouse: I'm really sorry about that. I already know how capacitors work in series and parallel, as well as how series resistor-capacitor filters work. It's just that I came across a parallel resistor-capacitor filter and I just wanted to know the differences in operation between the two. Again, my apologies. \$\endgroup\$ – D Brown Oct 28 '11 at 8:20
  • \$\begingroup\$ @D Brown: As I edited my answer for 3rd time and i hope it'll be helpful for you \$\endgroup\$ – Gouse Shaik Oct 28 '11 at 8:31
  • \$\begingroup\$ @D Browm:Be aware before you post the questions here this habit may cause an downvote for you and decrease your reputation. \$\endgroup\$ – Gouse Shaik Oct 28 '11 at 8:37
  • \$\begingroup\$ please post a schematic (and/or where it is you heard about these phrases), so we can understand what you're talking about. \$\endgroup\$ – Jason S Oct 28 '11 at 20:15

It's not clear what exactly you mean by series versus parallel resistor-capacitor filters. Posting a schematic of each would clarify this.

You probably mean series is something the signal passes thru, and parallel is something that works as a shunt. Note that the same thing that is a low pass filter in series is a high pass filter as a shunt, and vice versa.

Basically a capacitor will block low frequencies and short high ones. If you put it in series with a signal then it is a high pass filter. If you put it accross a signal, it will short the high frequencies thereby making a low pass filter. The value of the capacitance and the resistance it is working against tell you the -3dB rolloff frequency of the filter, whether high pass or low pass. This frequency is:

\$ f = \dfrac{1}{2 \cdot \pi \cdot R \cdot C} \$

When R is in Ohms and C in Farads, then f is in Hertz.


A capacitor in series or parallel with a resistor can be used to make a filter circuit that allows us to select frequencies.
RC circuit is used as an filter which consists of resistors and capacitor. RC Filter:
Simple combinations of passive circuit elements, i.e. resistors and capacitors, can be used to remove an unwanted signal component or enhance a desired one.
Frequency filters exploit the frequency dependence of the passive circuit elements and
Allow only specfic frequency ranges to pass from input to output.
There are two types of filter
-High pass filter.
-Low Pass Filter.

The functionality varies according to the arrangment of capacitors and resistors in parallel to the source.

For Parallel RC filter circuts go through these links.


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