Downloadable and online free and low-cost EE tools help engineers design and analyze circuits.
The internet is full of EE tools from equipment manufacturers, semiconductor manufacturers, independent EEs and hobbyists. Some are web-based that you can use with just a browser. Some you need to download and install on your PC while others you install on your smartphone. Some are general=putpose EE tools for circuit design, some add functions to your computer or phone, and some can help you with specific tasks such as designing antennas. No EE tools list can cover everything but this list can get you started. All entries have links embedded in the text. Click on any image to enlarge it in a new window.
Which online or downloadable tools do you use that are missing from this list? Add them in a comment below.
Manufacturers EE tools
Most of these are web-based applications. Click on any image to enlarge in a new window.
Tekbox Digital Solutions offers a free Decibel Calculator app for Windows within their downloads page.
Analog Devices has the well-known LTspice simulation tool for Windows and Mac. Many semiconductor companies provide spice models for their devices.
Analog Devices also has EE-Sim DC-DC converter design and simulation tool that you can download.
Würth Elektronik published The LTspice Simulator – Manual, Methods and Applications handbook, an essential tool for learning to use LTspice. Price: 49€.
Würth Elektronik also offers the well-known REDExpert online web-based design tool for component selection simulation and design.
Sierra Circuits has a free online impedance calculator for calculating the single-ended or differential impedance of PC board transmission lines. Sierra Circuits offers many other PC board-related calculators with links on that page.
Richtek has Richtek Designer, a web-based design generator and simulation tool for their line of power converter ICs.
Texas Instruments has two major web-based design tools, WebBench Circuit Designer and WebBench Analog Filter Designer.
Transmission Line Calculator from ARK RF Systems lets you calculate microstrip, stripline, coaxial, coplanar, and CPW with ground transmission lines.
A.H. Systems has a set of EMC and RF calculators that include field strength, VSWR, frequency/wavelngth, and magnetic-field conversions.
Independent EE tools
Ansys Electronics Desktop Student is a free download EM simulator for antenna, microwave, and PCB designs. Ansys has several other design tools for students or those wishing to try out their software.
Dipole Antenna and Resonant Frequency Calculators by MD & PhD candidate Łucja Zaborowska provides useful dipole antenna and resonant L-C web-based calculators.
Circuit Lab has a web-based spice simulation tool that lets you drag and drop circuit components such as op amps, transistors, signal sources, and passive components.
KiCAD ranks as the most popular free tool. It’s open source and supported by many engineers at CERN and the Raspberry Pi Foundation. If you’re looking for a free PCB schematic and layout tool that has legs and will probably grow in functionality, this is a good one.
QUCS (Quite Simple Circuit Simulator) is based on Spice with versions for PC and Mac. It lets you build virtual circuits such as a Peltz oscillator and plot their characteristics
Mobile EE tool apps
There are many electronic design apps out there. Search “electronic design apps” and you’ll find them. Some of the following are outstanding. While many of these are labeled as iPhone/iPad (iOS) apps, many are also available for Android. Several of these have been around for a decade or more and are updated regularly.
EE Toolkit (Free, with ads) or EE Toolkit Pro ($7.99, no ads) by Thomas Gruber for iPhone or iPad packs more than 160 applications into one app. Circuits include op amps, 555 timer, LEDs, and voltage regulators plus resistor color codes.
Audio Function Generator Pro ($5.99, no ads) by Thomas Gruber for iPhone or iPad can generate audio test tones (sine, rectangle, triangle, or sawtooth) as well as volume sweeps and frequency sweeps. View signals in the time domain or frequency domain.
Electronics Engineer Helper (free, with ads and in-app purchases) by Rostyslav Dovhalik for iPhone or iPad includes a host of electronics design and reference material.
EE Tools Lite (free, with ads) by Calctronics for iPhone or iPad includes a host of design tools, including filter design.
AutoCAD (free, with ads and in-app purchases) by Autodesk is a drawing viewer and editor for iPhone and iPad.
Autodesk Fusion (free, with ads) by Autodesk allows collaboration on 3D design for iPhone or iPad. You’ll need a Fusion account.
Eagle free download from Autodesk is a limited version of the full-featured tool for students and hobbyists. It is limited to two schematic sheets, boards with two signal layers (and multiple planes), and a total board area of 12.4 in².
Breadpad is a Spice simulator (free, with in-app purchases) by FreshBizOpps for iPhone and iPad uses a breadboard-based circuit entry model to generate transient and linear circuit analysis on simple circuits.
EveryCircuit (free, with in-app purchases) or “full version” for larger circuits ($14.99) by MuseMaze with schematic editor shows voltage, current and transient analysis output plots. For iPhone or iPad.
RF Toolbo
x Pro ($7.99) includes a host of RF-related calculators.
Free tools from Rohde & Schwarz include Pulsed RF Calculator, and Field Strength Estimator apps for iOS and Android.
Keysight has mobile apps for PCB trace impedance, microwaves, and an engineering calculator.
Be sure to add your favorite EE tools in the comments.
