track width formula for current carrying capcity

[vicky]

Hi

how to calculate track width for current carrying capacity just i want know the formula


Thank U

[randychase]

where I is the maximum current in amperes and A is the cross sectional area of the trace.

[randychase]

This formula is derived from the IPC-D-275 tables. It calculates the current capacity based on the maximum allowed temperature rise on the individual layers.

where T is the maximum temp rise, A is the cross sectional area and K is geometry factor, which is 0.048 on inner layers and 0.024 on outer layers.
randychase has attached this image:

[Skip Yutkus]

There is a calculator available at www.ultracad.com testing has shown its results to be derated somewhat but it will give you a safe guideline.

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