Low Pass Filter
Filter is a circuit designed to pass a particular frequency band all the while weakening the signal outside the band frekuaensi. In this article will be described one of the filters that exist in the field of electronics that is below the filter pass or low-pass filter. Low-pass filter is a circuit that will pass a signal from DC up to a cut-off frequency (ωc) and will withstand a certain signal frequencies above the cut-off frequency (ωc) of the circuit filter. Low-pass filter circuit can be constructed with RC or LC configuration. Low-pass filter circuit with component RC base prepared as follows.
The resonant frequency of the low-pass filter time constant following the value (τ) of the RC circuit.
Τ = RC
So that the cut-off frequency of the filter are:
fc = 1 / (2πRC)
the output of the low-pass filter of the input lag for:
Φ = tan-1 (ωRC)
The characteristics of this filter is shown in the figure below: