Operational Amplifier Applications Unit 3 – Low Pass Filter
UNIT 3 – LOW PASS FILTER
UNIT OBJECTIVE
At the completion of this unit, you will be able to determine the operating characteristics of low
pass filters by analyzing the performance of a single and double pole op amp filter circuit. You
will verify your results with an oscilloscope.
UNIT FUNDAMENTALS
A low pass filter is a circuit that passes input signals below a certain frequency and blocks
higher frequency signals.
The gain versus frequency characteristics of an ideal low pass filter are shown.
The point at which the filter stops passing and begins blocking input signals is the cutoff
frequency (fc).
The range of frequencies passed by the filter is the passband.
The range above the cutoff is the stopband.