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www.microwavejournal.com/articles/35125-sierra-circuits-launches-3-in-1-trace-width-current-capacity-and-temperature-rise-calculator
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Sierra Circuits Launches 3-in-1 Trace Width, Current Capacity and Temperature Rise Calculator

December 9, 2020

Sierra Circuits, Inc. has launched the Trace Width Calculator. This tool incorporates a unique 3-in-1 feature to calculate the trace width, maximum current capacity and temperature rise above the ambient for both internal and external layers. This calculator abides by the latest IPC-2152 standard.

Using this tool, a PCB designer can evaluate the following parameters:

• Trace width (W) – if the maximum current and the temperature rise above the ambient are given
• Temperature rise (ΔT) – if the trace width and maximum current values are given
• Maximum current (Imax) – if the temperature and the trace width values are given

The other parameters required by this tool are trace thickness (Th), ambient temperature (Ta) and trace length (L). This trace current capacity calculator also calculates additional parameters such as resistance of the trace at ambient temperature, the resistance of trace at high temperature (Ta + ΔT),
maximum voltage drop, and maximum power loss for a given trace length.

The default values of trace length and the ambient temperature are set as 1-inch and 25° C, respectively. However, these can be changed as required. This trace current capacity tool also lets you switch between different units as per your convenience.

What can you expect from Sierra’s trace width calculator?
For high-current PCBs, the trace width calculation is critical. Hence, we need to know how much trace width is enough to carry that high current. If trace width is not sufficient, then the trace may burn out, impacting the PCB functionality. 

Sierra’s trace width calculator tool not only gives you the trace width but also the amount of trace current and the temperature rise. You can alter any of these two parameters to find out the third one for a given trace thickness. This is the only tool that gives you this advantage, and it is also based on the latest IPC-2152 standard.

The IPC 2152 talks about how the temperature rises in various internal and external PCB traces as a result of current being passed through them. It gives the results in graphical format, and the basic idea was to study those graphs and put them into some curve fitting formulas for better understanding. Our tool is developed based on such formulas.

The surprising thing that has come from this standard is that the internal traces are also capable of carrying higher currents close to those of the external traces. 

Default tool parameters 
The default parameters of this tool are trace length and the ambient temperature, which are kept at values of 1-inch and 25° Celsius, respectively. However, these can be changed as required. The trace length and ambient temperature input fields on the calculator are used to enter the trace length and ambient temperature, respectively.

Their trace width tool also lets you switch between different units as per your convenience.

  • The units of temperature can be selected as degrees Celsius or Fahrenheit.
  • The units for length can be chosen as inches, mils, micrometers, millimeters, centimeters, or meters.
  • The input field has a feature where the user can use the desired units, which provides flexibility.

Why should you choose this trace width calculator?

Essentially there are four main parameters to be considered while designing traces on a PCB: 

  • Trace width (W)
  • Maximum trace current (Imax) 
  • Rise in the temperature (ΔT)  
  • Trace thickness (Th) 

As mentioned previously, if the Imax and ΔT are known then the trace width can be calculated for both internal and external layer traces.

The other parameters required by this tool are ambient temperature (Ta) and trace length (L). This trace width calculator also calculates additional parameters such as resistance of the trace at ambient temperature, the resistance of trace at high temperature (Ta + ΔT), maximum voltage drop and maximum power loss for a given trace length.