TINA-TI is TI’s circuit design and SPICE simulation tool. I’m a big fan of the software, but it’s not just because I work at TI. I’ve used other SPICE-based simulation programs over the years. While most are fairly easy to use and robust, there are several reasons I prefer TINA-TI.
TINA-TI has a simple schematic editor, but it also includes powerful tools, like noise analysis, variance analysis and fast Fourier transform for distortion analysis. An added bonus: it’s free.
But one of the biggest advantages for me as an applications engineer is that TINA-TI has many of TI’s ICs already included and ready to use, including a pre-drawn and linked symbol. When I get a customer support request, I can open TINA-TI, grab the SPICE macromodel for the IC in question and start making initial simulations. This saves me tons of time, and if you’re designing with a new TI device, it’ll do the same for you.
Today, there are more than 650 operational amplifiers pre-loaded into TINA-TI. The software also comes pre-loaded with comparators, fully differential amplifiers, voltage regulators and more – plus a category for other devices. You can often design a whole system with the devices included in TINA-TI.
But what happens if you don’t see the device you’re interested in listed in the “SPICE Macros” tab of the software? Don’t worry. Nearly all new TI amplifiers will have a completely assembled TINA-TI reference design available.
To see if a TINA-TI reference design is available for the device, just search for the part number on TI.com and visit the device page, which we call a product folder. Once you get to the device’s product folder, click on the “Tools & software” tab, as shown in Figure 1. You should see links for a macromodel and reference design in the models section.
Figure 1: Tools & software tab of the LMH5401 product folder
From here, you can download the reference design file, which is a TINA-TI native file format and will automatically open if you have TINA-TI installed on your computer. If you prefer to use your own simulation software, you can also download the macromodel for use in other programs. The reference design will only work in TINA-TI, though.
Once you’ve downloaded the TINA-TI reference design model and have it running, as shown in Figure 2, you can perform a variety of proof-of-concept simulations.
Figure 2: LMH5401 reference design circuit
For example, I always check DC operating conditions when looking at a circuit. I want to know:
- Are the power supplies the right voltage?
- Are the input voltages in the correct range?
- Is the common mode voltage set right?
A transient simulation will usually show these errors best, but you can also run a “Table of DC results” analysis to start. I usually skip the table and go straight for a transient simulation.
Figure 3 shows the results I got when I ran a transient simulation using the LMH5401 TINA-TI reference design. The LMH5401 is an 8-GHz, ultra-wideband fully differential amplifier (FDA) that can be used in AC- or DC-coupled applications that may require a single-ended-to-differential (SE-DE) conversion when driving an analog-to-digital converter (ADC).
Figure 3: Transient simulation results using the LMH5401 TINA-TI reference design
There are some interesting things going on in Figure 3. For example, why is the signal obvious when the amplifier is off, and why is the input signal impacted so much?
Check back on Friday, Dec. 19, for part 2 in this series, when I’ll answer these questions and walk you through some other helpful simulations.
Additional resources:
- Download TINA-TI to start working.
- Read other blog posts about working with TINA-TI, including this one about questions you may be too afraid to ask.