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Filter Wiz PRO active filter designer

Filter Wiz PRO active filter designer version 5 was released in the Fall of 2009, and is updated regularly. All future updates are free.

Whether new to active filters, or experienced in their design, Filter wiz PRO is the right application for you.

Unlike cookbooks, textbooks and simple freeware calculators, Filter Wiz PRO offers in-depth design and highly customizable solutions.


  • new Quality Factor (Q) versus Filter Order (Q-N) plot

    - now you can visually compare all available approximations to find not only which are All-Pole, and which have (more complex) notch stages, but also quickly find those Approximations with both low Filter Order and low Maximum Q (thus providing greater filter stability).

  • new Antialiasing Filter design

    - design an antialiasing lowpass filter for A/D conversion

  • new Op Amp selector and Slew Rate Calculator tools

    - find suitable op amp families by sorting on GBW, slew rate or quiescent supply current

  • upgraded interface

    - allows instant access to all completed phases of the filter design, and presents information and choices with clarity and ease of use
    - Version 5 works best with 1024x768 screen resolution or higher

  • built-in simulator

    - provides eSketch-like simulation of the filter design, including effects of op amp Gain BandWidth. The user can preview the gain response when selecting circuits for each stage. And now Filter Wiz PRO can export eSketch .ES1 files, providing two ways of transferring data from Filter Wiz PRO to eSketch PRO

  • up to 21 Approximations available

    - choose from 10 "standard" Approximations, plus 5 linear phase Approximations, and 6 Low-Q Approximations that are extremely useful for augmenting filter stability
    - Approximations include:
    Butterworth Chebyshev Inverse Cheby.
    Elliptic LSM Mod. Butterworth
    Bessel Low-Q Butter. Low-Q Cheby.
    Low-Q Elliptic Linear Phase Legendre

  • many circuit topologies to implement filter

    - includes new topologies (circuits), and many variations of existing topologies, including voltage divider inputs to better meet optimal stage gain requirements - topologies include:
    Sallen-Key Multiple Feedback Fliege
    Bach Twin-T KHN
    Tow-Thomas MB Berka-Herpy
    Akerberg-Mossberg PMG Natarajan
    Friend's SAB Boctor

  • cascaded stages

    - filters of order 3 to 20 are constructed of simpler first and second order stages cascaded together. Filter Wiz PRO lets you know what the circuit response should be for each stage, thus making tuning or troubleshooting easier.

  • export design as eSketch file

    - allows designer to optionally take advantage of Schematica's eSketch simulator for further analysis, without having to redraw schematic.

  • more selection aids

    - in addition to stage gain simulation, view indicators of stage Noise (resistor noise), GBW requirement, and Gain Spread. Also view design windows showing Input Impedance (vs frequency), Passive Sensitivity, Active Sensitivity, Dynamic Range, and Tuning instructions

  • Monte Carlo analysis

    - simulate gain spread due to inexact component values, with a choice of 3 probability distributions - Uniform, Gaussian and Worst Case

  • Temperature Effect analysis

    - determine response change due to environmental temperature rise and component temperature coefficients

  • "Strategy" help windows

    - view help topics appropriate to each design phase, accessible through "Strategy" buttons. All help topics are also available through a standard help file

Filter Wiz PRO can be freely downloaded for evaluation, without time restriction. Resistor values and some additional output data are masked. This masking is removed once a licence is purchased and the registration information is entered.

Click on any image to enlarge...

Specifications - the active filter type (low pass, high pass, band pass, band stop or user-defined) is selected, and the active filter specifications are entered

active filter specifications

Approximations - select an approximation to the ideal filter specification, using both the graphical filter response and the table of attributes


Cascade Sequence - optionally determine how poles and zeros will be combined, and in what sequence filter stages will be cascaded

cascade sequence

Select Topologies - select the actual circuits that will implement each stage. A number of indicators and graphs aid in the choice of circuits

select circuits

Calculate Values - the resistor and capacitor values are automatically calculated. Capacitor values can be scaled up or down, with resistor values being altered accordingly

calculate values

Response Graphs - view the simulated response curves (voltage, phase, delay) for each stage and for the whole filter. Temperature effects and voltage spread can be calculated (Monte Carlo)

final response

Filter Circuit - the final combined filter circuit is displayed

filter circuit

Tabular Data - tabulated data for Bill of Materials, frequency response at selected intervals, Spice Netlist, Transfer Function and Poles and Zeros

tabulated data

Please download Filter Wiz PRO to view the many design windows and aids.

Note that resistor values and some additional output data are masked. This masking is removed once a licence is purchased and the registration information is entered.

Comparison of Filter Wiz Lite and Filter Wiz PRO:

Filter Wiz software Lite PRO
Approximations 5 21
Total Circuit Topologies 32 79
Capacitor scaling YES YES
Antialiasing lowpass filter YES YES
Export to eSketch file YES YES
E-Series resistor substitution YES YES
Internal simulator   YES
Low-Q (MCP) Approximations   YES
User-defined filter stages   YES
User-configurable pole-zero pairing   YES
User-configurable stage cascading   YES
Monte Carlo analysis   YES
Temperature Effect analysis   YES
Input impedance vs frequency   YES
Bill of Materials   YES
Quality Factor vs Order Diagram   YES
Price (USD) FREE sale:$49.00

Filter Wiz PRO version 5.8.3 [updated July 20, 2016]

Filter Wiz PRO active filter designer can be downloaded for free and evaluated indefinitely.

A single-user license authorizes the licensee (only) to operate the software on two computers, such as a work computer and a home computer.

Resistor values and some additional output data are masked. This masking is removed once a licence is purchased and the registration information is entered.

Compatible with Windows 7, Vista, XP, 2K

555 Timer PRO

EXE setup file:

FWPRO_Setup.exe 8.52 MB Filter Wiz PRO active filter design

Zipped setup file:

FWPRO_Setup.zip 8.50 MB Filter Wiz PRO active filter design

Upgrading from version 4? The upgrade is free. Please install Version 5 to a new folder.

Please report any downloading problems to support@schematica.com.