Month: July 2026

This post explores the workflow for migrating LTspice circuits (.asc files) into TINA, DesignSoft’s circuit simulator. We demonstrate how to import, execute, and evaluate these schematics locally on a computer. A key takeaway is the full cross-compatibility of the resulting .TSC files, which ensures a unified workflow between the TINA desktop application and the TINACloud platform.

Click here or on the image above to watch this blog presented as a video tutorial.

1. Importing and Basic Analysis (RLC Circuit Example)

The conversion process is straightforward. By using the File > Import > LTspice command, users can bring LTspice designs into the TINA schematic editor. The tutorial demonstrates this using an educational RLC circuit.

Transient Analysis

Once the schematic is imported, users can perform a Transient Analysis to examine the circuit in the time domain.

• Visualization: Waveforms are displayed in a diagram window.
• Customization: The “Collect Curves” function allows users to plot multiple signals (e.g., input and output) on the same coordinate system.
• Identification: The “Auto-Label Curves” tool helps identify voltages and currents directly on the graph.

AC Analysis

To explore frequency-domain behavior, the AC Transfer Characteristic is used. Beyond standard Bode plots, TINA provides:

• Multi-Diagram Output: Users can generate Amplitude, Phase, Nyquist, and Group Delay diagrams simultaneously.
• High-Resolution Results: By configuring start frequency and the number of plot points, users can generate detailed, high-resolution outputs across multiple tabs.

2. Symbolic Analysis

Another highlight of the tutorial is the ability to derive a circuit’s Transfer Function symbolically as an exact mathematical formula. This provides insights beyond numerical simulation, assisting in documentation and verification

Analytical Verification: The tutorial demonstrates how to extract this formula via the Equation Editor and paste it directly onto the schematic.

Curve Comparison: Users can plot the symbolic transfer function and overlay it on numerical simulation curves. A perfect alignment between the two confirms the circuit’s behavior and the accuracy of the model.

3. Active Filters and Operational Amplifiers

Using an active band-pass filter circuit based on the Analog Devices ADA4000-1 operational amplifier, the video shows how these analysis tools apply to standard building blocks.

The workflow:

1. Import the circuit file.
2. Run AC Analysis to generate the combined Amplitude and Phase Bode Plot.
3. Run Symbolic Analysis to derive the analytical transfer function.
4. Overlay the analytical curves onto the numerical plots to verify that the results align.

This also demonstrates that ideal operational amplifiers are well-suited for active filter synthesis, as the results consistently match the numerical simulations.

4. Advanced Evaluation: The LT8640 Regulator

The final section covers the simulation of a synchronous step-down regulator, specifically the Analog Devices LT8640.

Average vs. Switching Models

A critical distinction in this example is the use of simulation models:

• Average Models: These are utilized for exceptionally fast execution in the web browser and allow for AC frequency sweeps on the regulator’s control loop, which is vital for evaluating stability.
• Switching Models: These provide high-fidelity time-domain simulations, but at the cost of longer execution times.

The LT8640 model used in TINA is an equivalent SPICE model independently developed by DesignSoft, based on manufacturer datasheets. This model follows standard SPICE conventions, making it compatible with other major simulators as well.

Presentation and Customization

To make simulation data more interpretable, the tutorial highlights several layout customization options:

• Text Labels: Adding labels directly to curves for quick identification.
• Separate Curves: Using this function to isolate signals into stacked diagrams, which helps in identifying phase and gain margins when viewing frequency responses like Loop Gain.

By following these procedures, engineers can ensure that designs migrated from LTspice are fully functional, verifiable, and well-documented within the TINA and TINACloud environments.

• 📺 Watch the complete video tutorial: Watch on YouTube
• 🌐 Explore the software & features: Visit TINA Official Website

In this post, we will show you how to seamlessly convert LTspice circuits into TINACloud.

By converting these circuits into TINACloud, you can instantly run and analyze them anywhere—without any installation—on virtually any device with a modern web browser, including PCs, laptops, tablets, smartphones, Chromebooks, and many Smart TVs, regardless of whether it’s running Windows, macOS, Linux, iOS, or Android.  

It is important to note that this conversion process is also available in the offline version of TINA, allowing you to perform the transition locally.

The resulting .TSC files are fully cross-compatible, providing a seamless workflow between the offline desktop software and the online TINACloud environment. 

Click here or on the image above to watch this blog presented as a video tutorial.

Example 1: Educational RLC Circuit

TINACloud includes several ready-to-use sample circuits, which you can find under the Examples/3rd Party files/LTspice folder.

Let’s start with a simple educational RLC circuit. This is how the circuit looks in LTspice. 

1. Importing the Circuit

• Navigate to the Examples / 3rd Party files / LTSpice folder.
• Select the RLC circuit file (RLC_1.asc) and click Open.

2. Running a Transient Analysis

First, we will run a Transient Analysis. Go to the Analysis menu and select Transient… As soon as the simulation completes, the resulting time-domain waveforms are displayed cleanly on the screen.

Using the Collect Curves command from the View menu in the Diagram window, you can also plot the input and output waveforms on the same coordinate system.

You can also label the curves with their signal names using the Auto-Label Curves icon in the Diagram window.

3. Configuring AC Analysis

Next, let’s explore the frequency domain. Navigate to the Analysis menu and select AC Analysis > AC Transfer Characteristic…

In addition to standard AC Bode plots, TINACloud features advanced calculation capabilities, allowing you to easily generate Amplitude, Phase, Nyquist, and Group Delay diagrams.

Select the AC Bode, Amplitude, Phase and Nyquist diagrams, and set the start frequency to 10 kHz and the number of points to 1,000 for a high-resolution output, then click Run to execute the analysis.

Four separate tabs will appear, displaying the Amplitude, Phase, Nyquist and Amplitude & Phase (Bode) diagrams.

4. Symbolic Analysis in TINA and TINACloud

A unique feature of TINA and TINACloud is the ability to derive a circuit’s Transfer Function symbolically, presenting it as an exact mathematical formula. This allows engineers and students to gain deeper insights into circuit behavior-including poles, zeros, gain, and frequency response. This symbolic expression can also be used for analytical studies, documentation, optimization, and verification, moving beyond a sole reliance on numerical simulation results.

Note: While symbolic transfer function derivation is only possible for linear circuits, you can still analyze active filters implemented with op-amps. In TINA and TINACloud, nonlinear operational amplifier models are automatically replaced with ideal op-amp models during symbolic analysis. This provides highly accurate results, allowing the transfer function to be derived and analyzed symbolically.

Running Symbolic Analysis

To perform Symbolic Analysis, open the Analysis menu, select Symbolic Analysis, then Symbolic AC Transfer, and run the analysis.

The analytical form of the Transfer Function will immediately be displayed on your screen.

You can now insert the symbolic expression into the TINACloud Text Editor and place it directly onto the schematic, making the analytical results part of your circuit documentation. In the Symbolic Result window click on the “Send to” tab then select the “Text editor”.

Note that the formula can also be edited within the Text Editor, though we won’t cover those editing features in this tutorial.

Once the formula appears in the Text Editor, click OK. The formula is now attached to your cursor. Position it wherever you like on the schematic, and left-click to place it.

Plotting and Comparing Results

Beyond formulas, you can also plot the analytical transfer function to compare it directly with your numerical simulation results.

In the Symbolic Results window, simply click the Draw Diagram button. The plot of the Transfer Function will appear. To make comparing the analytical and numerical results easier, click on the curve and change its color to green. Next, click the curve again, then click the Copy curve icon to save it to your clipboard. Now, switch back to the previously calculated Ampl 1 tab, and use the Paste Curve icon to overlay the symbolic result directly onto the numerical curve.

As you can see, the two curves match perfectly within the line width.

Active Band-Pass Filter (ADA4000-1)

For our next example, we’ll look at a similar band-pass filter, this time built around the Analog Devices ADA4000-1 operational amplifier. This circuit is a standard building block for what we call active filters, and here is what it looks like in LTspice:

File Import and Conversion

To bring this into the TINACloud workspace, save the circuit to your local Downloads folder. Next, use the Upload command to convert the file and save it as ‘Active Bandpass Filter.tsc’.

Running AC & Symbolic Analysis

Since the setup is similar to our previous example, we’ll focus just on running the AC and Symbolic Analyses for this simulation. We’ll start with the AC Analysis, which generates our combined Amplitude and Phase Bode Plot.

Go to the Analysis menu, select AC Analysis, AC Transfer Characteristic. Click Run.

The combined Amplitude and Phase Bode Plot appears.

Next, run the Symbolic AC Transfer Analysis. Just as we explained in the last video, TINA and TINACloud automatically swap out the nonlinear ADA4000-1 for an ideal op-amp. This substitution makes symbolic analysis possible, allowing TINACloud to generate the analytical transfer characteristic.

Plot Visualization

Now, let’s compare this analytical result with our numerically calculated Bode Plot. In the Symbolic Result window click the Draw Diagram  tab. Three plots will appear: the Amplitude, the Phase and the combined Bode Plot.

Comparing and Overlaying the Curves

To easily compare the two methods, first change the color of the analytical Amplitude Plot to green, and copy the curve to your clipboard. Then, switch over to the numerically calculated Bode Plot tab, and paste the green curve directly into the Amplitude Plot.

Repeat this exact same procedure for the Phase Plot.

Final Analysis and Conclusion

When you look at the results, you can see that the numerically calculated curves align perfectly with the analytical curves. As we’ve emphasized in previous videos, this excellent agreement demonstrates exactly why ideal operational amplifiers are so widely used in active filter synthesis.

Example 3: Simulating the LT8640 Step-Down Regulator

Our final example in this video is a practical evaluation circuit based on the Analog Devices LT8640 step-down regulator.

Under its current configuration, this synchronous step-down regulator converts a 24 V input voltage into a regulated 5 V output voltage capable of delivering up to 5 A of output current.

Importing the Schematic into TINACloud

To convert and open this circuit in TINACloud, first save the circuit as an LT8640.asc file in LTspice to an easily accessible location on your computer.

Use the Upload command to upload and convert the LT8640.asc circuit file into TINACloud.  

After a brief importing process, the fully mapped schematic will automatically appear in the TINACloud circuit editor.

Important Note on the Simulation Model: The LT8640 model used in this circuit is an equivalent SPICE model independently developed by DesignSoft, based entirely on the publicly available manufacturer datasheet. Because it follows standard SPICE conventions, this versatile model operates seamlessly not only in TINA and TINACloud, but also in PSpice and other major SPICE simulators. Our independently developed model library is continuously expanding.

If you require a specific device model that is not currently included in TINA or TINACloud, please contact DesignSoft.

Running Transient Analysis (Average Model vs. Switching Model)

Now, let’s run a Transient Analysis. Instead of a slow switching model, this simulation uses an average model to ensure exceptionally fast execution times right in your web browser. This approach also provides a major advantage: it allows you to run AC frequency sweeps on the regulator’s control loop.

Select Transient from the Analysis menu and click Run. Once the simulation completes, the waveforms will appear instantly.

Customizing the Waveform Display

To make your simulation data easier to interpret and present, you can easily customize the visual layout of the waveform viewer:

• Add text labels directly to individual curves to quickly identify voltages and currents.
• Use the Separate curves function to isolate different signals and view the results in dedicated, stacked diagrams.

Running AC Analysis (Bode Plots and Loop Gain)

Because we are utilizing an average model, we can now run an AC Analysis to evaluate the stability of the power supply.

Execute the AC sweep, and TINACloud will instantly display the Bode diagram of both the power supply output and the circuit’s overall Loop Gain. To present this frequency response clearly and identify your phase and gain margins, simply add distinct labels directly onto the resulting gain and phase curves.

This concludes our blog on converting LTspice circuits into TINACloud. The same conversion procedure is supported by both TINACloud and the offline desktop version of TINA, and the resulting .TSC files can be used interchangeably in both environments.

• 📺 Watch the complete video tutorial: Watch on YouTube
• 🌐 Explore the software & features: Visit TINA Official Website