Op-Amp Based Band Pass Filter
Equivalent Circuit @ DC
(DC feedback)
Equivalent Circuit @ ω=ωo
Circuit Analysis
(Solve for Vout/Vin)
Second Order Bandpass Filter
Bandwidth of Second Order Bandpass Filter
Cadence Simulation
Tunable Bandpass Filter
BPF at 100 Hz12.396 mS
15.15 mS
Vout is delayed by 2.76 mS, approximately ¼ of a period.
Closer Look at 950 Hz
(Vout is larger than Vin!)
Question
• What is tunable?– Not a capacitor! (Not an absolute
requirement, since you can always do switches to add/remove capacitors)
– Resistor, but which resistor? Consequnce?• R3+R4• R1• R2