It’s not a good idea to do the analog filter design.

This tool eliminates the need for filter suggestions and helps you design low-pass, high-pass or band-pass filters with the required features with shorter preparation times (Figure 1). In addition, it provides a rigorous analysis of the theoretical and practical performance of the filter.

Figure 1. Filter type

What is the working principle of the Filter Design Wizard?

Are these recommendations based only on passband and stopband definitions?

No, it doesn't stop there. It covers the entire process from defining characteristics to filter response characteristics, as shown in Figure 2. You can use this option to select the type of filter response (such as Butterworth, Bezier, Chebyshev, etc.) to define the transition from passband to stopband. You can also choose between a less-level circuit topology or a quick setup circuit topology.

Figure 2. Defining properties in the amplitude view

Through a variety of available views (such as amplitude, phase, step response, power, and noise), the Analog Filter Wizard tool lets you check for performance changes when feature parameters change. As shown in Figures 2 and 3, the amplitude and phase views can help you understand the phase and amplitude effects of the signal.

Figure 3. Phase view

The level view shows the characteristic parameters of the op amp filter and their characteristics (Figure 4). This view makes it easy to grade the filter.

Figure 4. Filter level view

Overshoot and ringing define the distortion of the waveform, which can be analyzed by the filter step response obtained from the step response view (Figure 5).

Figure 5. Step response of the filter

After the theoretical characteristics are determined, the next step is the circuit design, as shown in Figure 6. At this point, the Analog Filter Wizard tool gives recommendations based on the type of optimization specified, such as power, noise, or voltage range. You can choose to use the recommended device or choose your own.

Figure 6. Component selection

While the analog filter wizard tool selects the most appropriate device for the desired characteristics, it may be difficult or impractical to find and use a device that is identical in its recommendation. Therefore, you can flexibly select the resistor and capacitor tolerances through the component tolerance function (Figure 7). At the same time, you can also see how the adjustment tolerance affects the performance of the filter.

Figure 7. Defining component tolerances

Figure 8 shows the final circuit design using the correct amplifier for your circuit simulation or prototyping.

Figure 8. Final circuit

The Analog Filter Wizard tool is very practical and allows you to check the performance optimization of the filter at each step, from defining filter characteristics to defining tolerances. These features help fine-tune your design at every step of the process. They also offer greater flexibility, saving valuable effort by getting the best design with fewer iterations.