• No ripple can exist in the output, but non-linear phase shift is allowed.
• The frequency response must be as close as possible to the ideal filter response.
• Signals of frequency 0 ~ 5 KHz are only allowed to pass through the filter with a desired gain of 4dB . Other frequencies should reduce at least 100 times of gain for every 10 times of frequency increase.
• capacitor of 0.01uF must use in the active filter design due to its high availability in the stock.
• Minimize offset error of your design
My answer:
no ripple means butterworth, 4 db means this is HPF
Very very confusing !
How can you calculate resistors without knowing the circuitry ?
Just two short comments:
1.) Gain of 4 dB in the passband of the lowpass means: Ao=+1.58
2.) Factor 100 per decade means: 40 dB/Dec >>> low pass of second order.
How you know the Ao is 1.58 and what are the following steps ?any guidance for me in this question ? Added after 1 minutes:
and low pass and high pass is see the Apb ,if positive value it is high pass,if negative value it is low pass.am i correct ?
A Sallen-Key second-order filter has a Butterworth response if its two resistors are the same and its two capacitors are the same and its gain is 1.58 (+4db).