a a second order sallen and key low pass active

Question

(a) A second order Sallen and Key Low Pass Active Filter has these component values

R₁=R₂=15 kΩ, C₁=C₂=1 nF and the feedback resistors are R₃=3.9 kΩ and

R₄=2.3 kΩ.

(i) State the equation of the filter transfer function

(ii) Use the Standard Active Filter Tables to determine what type of filter this is

(Chebyshev, Butterworth or Bessel)

(iii) Find the cut-off frequency

(iv) Determine the voltage gain in the pass band

(v) The attenuation in dB and the phase shift at twice the cut-off frequency

(vi) Sketch the frequency response

(b) Build the above active filter using the μA741 operational amplifier and perform a frequency response test on it.

(c) Compare the frequency response results of the ideal filter of (a) and the practical filter of (b) respectively with a computer simulation.