GigaTest Labs Comments on IConnect Software
Product: IConnect Software
Dr. Bogatin is responsible for teaching some of todays brightest engineers in cutting edge test and measurement practices.
Dr. Bogatin uses the IConnect Software for recording, storing and comparing measured TDR and TDT waveforms among various samples, preparing measured data for display in presentations and papers, separating measurement artifacts from real effects, and building high bandwidth models of interconnects from TDR measurements of IC packages and circuit board structures.
When asked to describe his experience using IConnect, Bogatin said:
What I recommend to all of my students is that if you have a TDR and you don't use IConnect, you are missing more than 80% of the information that is really available in the measurement. All you can ever hope to get are simple first order models if you are limited to just the front screen of the TDR. IConnect gives you access to this missing 80%, allowing you to extract accurate, high bandwidth models of interconnects.
The tool is quite intuitive to use with a learning curve all of five minutes.
When looking at uniform high impedance transmission lines, I often see the reflected voltage rising up as you move down the line. I used to think this was due to the losses in the line. However, before IConnect, I was never able to put in the numbers to confirm this effect.
After my first simulation I realized that the rising up of the reflected signal was completely unrelated to the losses in the line under test. It was all due to the losses in the cable from the TDR to the test line. Using a model of an ideal lossless transmission line, I was able to get excellent agreement with the measured response of the real line, only when I took into account the signal actually coming out of the TDR, not the ideal Gaussian edge most folks assume for the TDR. I could only do this analysis with IConnect.
Using the simple user interface, I can take a TDR measurement, build a candidate circuit topology and manually optimize a model whose simulated response overlaps the measured response, typically in less than 10 minutes. By comparing the measured and simulated response, I have immediate confidence in the accuracy of the model. I can routinely extract via inductances of less than 100 pH and capacitance discontinues less than 50 fF.
There is no way of extracting the capacitance or loop inductance of a small package lead from the front screen of the TDR. Using IConnect, I can fit an L or C model for the lead and get the parameter value in just a few minutes."
As modern signaling standards push digital designs to the gigahertz and gigabit ranges, interconnect performance becomes a key factor in enabling reliable system operation. Signal Integrity issues such as reflections, crosstalk, frequency dependent transmission line loss and dispersion can significantly degrade system performance and reliability. Ability to simulate and accurately predict the effect of these signal integrity issues is critical to achieving a working design, and this ability is contingent on the designers ability to obtain accurate interconnect models for each part of the interconnect link from the driver chip, through the package into the daughtercard; through a high-speed backplane connector to the backplane, and to the cable interconnect between subsystems.Other factors also come into play. In the present environment, cost savings associated with the necessary test and measurement are also a key factor. If you are not using TDA System's IConnect you are missing the majority of information available to you and your testing is much more difficult than it needs to be.