ne Impedance Calculator                                     


Industry-Leading Accuracy


  • 2D (BEM) field solver precision

  • Characteristic impedance, edge-coupled & broadside-coupled differential impedance

  • Relative Signal Propagation with 'Matched Delay Optimization'

  • Termination Planner - Series Termination based on Distributed System

  • Unique field solver computation of multiple differential technologies per stackup

  • Heads-up impedance plots of signal and dielectric layers

  • Extensive Dielectric Materials Library - over 30,700 rigid & flexible materials up to 100GHz

  • Interfaces to Allegro, Altium Designer, Excel, HyperLynx, OrCAD, PADS, Zmetrix TDR, Zuken and IPC-2581B

Click here to request a free 14-day evaluation.


Industry-Leading Ease of Use


Start with one of the 8 default stackups, rearranging to accommodate your specific design needs by adding or deleting signal, plane and dielectric layers, dragging and dropping single or multiple layers, and instantly re-calculating the entire multilayer stackup to solve for the desired single-ended, edge-coupled, and broadside-coupled differential impedances.

  • FastIndustry leading impedance-simulation speed-across the entire stackup.

  • Accuratethe precision you expect from an industry-leading 2D Field Solver (BEM).

  • Easy to usequick, intuitive, and easy to learn spreadsheet-like interface, with 9 default stackups.

  • Practicalinsert specific dielectric materials to simulate the actual materials used by your fabricator.

  • Differential Pair integrationsolve impedance for multiple differential technologies per stackup.

  • Affordablefrom entry-level configurations to unlimited functionality—you can choose the solution that best meets your design needs.


Click here for pricing information.

Click here to request a free 14-day evaluation.


Watch demonstration videos:

Watch the EDA interface videos:



I  just received results on the boards that I have been working on including actual TDR-measurements from the Chinese subcontractor making the pwbs, and they were close to spot on.


The laminates used (Kingboard) were not part of your library, but the material datasheet data was inserted and this was a pure success. Your software will be on the top of my list of investments in the near future, and I will highly recommend your products to all customers and colleagues from now on!


PS. The Chinese subcontractor and I were having quite a discussion back and forth on the way to design these boards for the correct impedances. They were making use of Polar SW (of course) and I was using your ICD Stackup Planner evaluation SW in the effort to have the right design parameters “nailed down” and finally handed to the draughts persons.


I am so glad that I insisted on the data I had calculated with your assistance! It certainly pays off!


Mikael Jensen
MicMac Engineering



I was very impressed after using the latest version of the ICD Stackup Planner, but I was even more satisfied when I exported Excel data to the Engineering OEM and Manufacturing location that I was working with. Their feedback let me know that this was a more complete, clear/readable set of information than they had ever received! The clear concise and readable Excel format pastes easily into the schematic for future reference also.

Karl Bates

ConnectPCB, Inc


Multiple Differential Pair Definitions per Layer

Differential Impedance Calculator, Transmission Line Impedance Calculator, embedded Stripline, Microstrip, Impedance Calculator




iCD Stackup Planner is the first stackup planning products to enable field-solver computation of multiple differential pair definitions per layer. So, if you’re pushing the technology envelope—with differential DDRx clocks, SATAx, USBx, and PCIe pairs sharing the same layers—you now have a stackup planning and documentation tool that can accommodate your differential impedance planning process right out of the box. As you insert a new differential pair on any signal layer, Stackup Planner automatically calculates both the single ended (characteristic) and differential impedance for each layer and pair.

For example, USB specifications call for 90 ohm differential impedance. If you want to route a DDR4 clock, targeting a 80 ohm differential impedance on the same layer, you can solve for both impedance targets on any layer of the stackup concurrently—by adjusting trace widths and spacing. The ability to dial in all of these values proactively, before laying out the board, is critical, as the trend continues toward lower voltage swings, and tighter noise margins. All of these values can then be exported to CSV to include in an Excel spreadsheet for documentation—detailing all differential pairs on all layers of the PCB.


Dielectric Materials Library


The Stackup Planner FX-HDI includes a customizable Dielectric Materials Library, taking In-Circuit Design's industry-leading field solver accuracy one more step toward the actual, fabricated circuit board configuration. By collaborating with your preferred PCB fabricator on their standard, off-the-shelf core, prepreg and solder mask materials, what you calculate—in Stackup Planner FX-HDI—is as close to the real thing as you're going to get. The Dielectric Library Editor comes with a sample library of commonly used core, prepreg, and solder mask materials, and it can be easily customized and/or shared with your fabricator.




With the latest release (Jan 2017), new materials have been incorporated into the Dielectric Materials Library to bring the total count to 30,700. For a complete list of the manufacturers and products included in the library please click here.


There are also a number of ultra-thin Embedded Capacitor Materials - Planar Capacitors and Flex materials.



PCB Interfaces

Stackup translation to popular PCB formatsincluding Allegro, Bidirectional interfaces to Altium S09  and AD13, AD14-17, Allegro, HyperLynx LineSim and BoardSim, and PADS are available now. The IPC-2581B format supports Allegro, OrCAD CR8000, PADS Pro and Xpedition.


What is the accuracy of the iCD Stackup Planner?  




Advanced Layout Solutions, in the UK, have done a comparison of a number of impedance calculators to judge their accuracy. iCD edited their drawing to include data from the iCD Stackup Planner using exactly the same stripline parameters. The results are extremely close, with the iCD Stackup Planner a mere 0.8% off Polar's Si8000 which was used as the benchmark.



Dr Eric Bogatin published an article "The Absolute Accuracy of 2D Field Solvers" in the July 2004 edition of Printed Circuit Design & Manufacturing magazine. In this article, Bogatin compared the absolute error of the calculated impedance of microstrip traces for HyperLynx and Si8000 using the Ansoft 2D field solver as the reference. iCD edited the above drawing to include data from the iCD Stackup Planner given the same parameters. Again, the results are very close, with the ICD Stackup Planner performing better overall than Mentor's HyperLynx and Polar's Si8000 compared to Ansoft.



Dr Eric Bogatin and Gaurav Narula published a column "Field Solvers for Transmission Line Analysis: How Similar are They?" in the December 2015 edition of Printed Circuit Design & Manufacturing magazine. In this column, six different field solvers (Polar Si9000e, ADS, QUCS, HyperLynx, Simbeor THZ and Sonnet) were compared. iCD edited the diagram to insert the iCD Stackup Planner (red), given the same parameters, and again found the results to be very close.


What our customers are saying:


I am very pleased with the recent CPW update, as it will greatly help me keep as much copper as possible without impacting signal integrity.

All in all, please pass my complements to the chef. It's a very handy tool so far, and it has been proven time and again by several board houses that are impressed with how well my supplied geometries match the impedance goals - and there has been no complaint whatsoever with the Excel output from the tool. The board manufacturers seem to like having such a well-organized stackup description that they can use.

Global Technical Systems

March 2017


By the way, I just finished a 16 Layer board with a ton of diff traces...98 to be exact. The planners were invaluable for this layout design. My board shop had some minor changes to the dielectric thickness on a couple of layers to meet IPC class 2, but that was it. Testing is about complete with only a resistor value change. SI and PI analysis was as expected, no issues. Thanks again Barry for an outstanding product.

Bill Farmer
April 2016

The software is awesome! I was able to very quickly get the stack up that I needed.

Research Engineer
March 2014

Just a word of thanks for a great PCB design tool. I did a video board with DDR2 memory a while ago on Altium. Thank you for your routing tips for DDR2, which I got off the internet. They helped a lot and the board now works like a dream. I will continue to follow your articles in the PCB magazine. It’s people like yourself that make life so much easier for the rest of us. Thanks once again for your insightful articles in The PCB Magazine.

Steve Knobel, Senior CAD Designer, CID+, Advanced Technologies & Engineering
December, 2011 



Never got such enormous support like you did. Thank you very, very much.


Erwin Ebner

Addiande GmbH

December 2011



The ICD Stackup Planner has proven very useful especially for highlighting the affects of builds and other amendments on the calculated impedance to the customers. It is both flexible and concise with only a very short learning curve required to use confidently.


Pete Saunders

GSPK Circuits Ltd UK - Global supplier and manufacturer of printed circuit boards

April 2011



I purchased the ICD Stackup Planner and just love it. I learned the value of preplanning my layer stack for Zo and Zdiff by using the evaluation software. Thanks again for a super product.


John Osiek

DCA - Digital Media Solutions

October 2010



The design of reliable multilayer PCB’s becomes more critical as signal edge rates increase in speed. Traces interconnecting digital devices form transmission lines that are a vital part of the circuit design. Determining the trace impedance allows for the correct termination of the transmission lines. Boards designed with this in mind will demonstrate superior signal integrity and lower electromagnetic emissions.


The ICD Stackup Planner is an easy to use, affordable tool that provides a clear representation of the PCB stackup and interactively calculates characteristic and differential impedance with adequate precision.


When the impedance is critical, the accuracy becomes limited by the PCB fabricator’s process tolerances and the material characteristics.  However, the ICD Stackup Planner provides a ready reference to a wide range of PCB materials, used by most fabricators, and allows the user to add their own material library entries.


This tool is essential for both engineering design teams and PCB fabricators and I highly recommend it.


R. D. Jeffery PhD

June 2010



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