3) Low-Pass Filter Design and Testing Let the desired signal be an AC with amplitude of 1V and frequency of 1 KHz. Let the "noise" signal be AC with amplitude of 0.5V and frequency of 8KHz. Need to design an op amp low-pass filter (as in the lecture notes). You need to choose the cutoff frequency f-fe. (Hint: fc must be slightly larger than the desired signal's frequency [1.5 to 2 times larger may be a good choice] but sufficiently smaller than the noise frequency. You may have to experiment with a few possible choices]. Test the filter both in AC Sweep (asking "Is f= fc located as designed?") and in Transient (as in the demonstrated example in the lecture notes, asking "Is the amplitude of the output noise small enough relative to the amplitude of the desired output signal?"). 93 A