【Active filter design function】 ●〜It can be used to instantaneously design various active filters simply by inputting the specifications. 〜 ● ● It can design LPF, HPF, BPF, BEF, all path filters using an operational amplifier. ● It can specify characteristics of Chebyshev, Butterwoth, Bessel, simultaneous Chebyshev (ellipse). ● It conducts design with various circuit compositions such as multiple feedbacks, VCVS, sullen key and the like. ● It calculates the necessary degree from the indicated specification and designs up to 12 degrees (up to 8 degrees for Bessel characteristic).

〜Operation procedure〜 1. Select the design item such as LPF design. 2. Select the characteristic page such as Chebyshev, Butterwoth and the like. 3. Enter the specification and circuit format. 4. Press the design button 5. The circuit diagram is completed. 6. The simulation command will transfer the data to a simulator such as S･NAP-Pro and immediately conducts simulation.

【Example of Butterwoth LPF design】 ● ● This is the example of design of Butterwoth LPF by the multiple feedback type. ● It is specified that cut off shall be 1 KHz and it attenuates 40 dB at 2 KHz. ● As a result, it is designed at 7 degrees. ● As a result of simulation, attenuation of 42dB is confirmed at 2 KHz. 【Example of Chebyshev HPF design example】 ● ● This is the example of Chebyshev HPF designed by VCVS type. ● It is specified that the path band edge shall be 2 KHz and it attenuates 40 dB at 1 KHz. ● As a result, it is designed at 6 degrees. ● As a result of the simulation, attenuation of 45dB is confirmed at 1 KHz。 【Example of simultaneous Chebyshev (eclipse) BPF design】 ● ● This is an example of eclipse BPF designed by negative feedback type. ● It is specified that the central frequency shall be 1 KHz, the pass band frequency shall be 300 Hz, and it attenuates 30 dB in the inhibition band. ● As a result, it is designed at 3 degrees. ● As a result of the simulation, attenuation of approximately 70 dB is confirmed at 1.38 KHz。 Moreover, it can be found that bounce in the ﾊinhibition zone is 30 dB or less. 【Example of Butterwoth BEF design】 ● ● This is an example of Butterwoth designed by the status variable type. ● It is specified that the inhibition frequency shall be 1 KHz and it attenuates 30 dB at 1 KHz. ● As a result of the simulation, attenuation of 50 dB or more is confirmed at 1 KHz. ● BEF is comprised only of the status variable model. 【Example of all path filter design】 ● ● This is an example of the all path filter designed by the delay phase. ● It is specified that it shall show a delay phase of 45 degrees at 1 KHz. ● As a result of simulation, delay phase of 45 degrees can be confirmed at 1 KHz. Top of the Page Copyright(C) 2000 MEL Inc.