Free online calculator
Example Draw 0.35 mm (14 mil) — IPC minimum is 0.3004 mm / 11.83 mil
Empirical IPC-2221 formula — a design estimate, not a manufacturer guarantee.
Area = mil², then width = area ÷ (1.378 mil of copper). k = 0.048 for an external trace.
What you enter
AWG ↔ mm²The gauge is geometric, not a lookup table: mm, and . Resistance assumes copper at 20 °C.
Controlled impedanceA trace over a single reference plane, solved backwards from IPC-2141's own closed-form approximation: . Good to a few percent for 0.1 ≤ w/h ≤ 2 — the…
Heatsink / thermal— the heatsink only gets what is left of the budget after the package and the interface have taken theirs.
Wire voltage drop, where for a round trip. The ohms per metre come from the AWG table.
Pull-up resistorkeeps the driver inside its sink rating, and keeps the released line above the input threshold.
RC filter— the −3 dB point, where the output has fallen to 70.7 % of the input. R in series, C to ground: C’s impedance falls as frequency rises, increasingly…
RC snubberTwo-measurement method. You are giving the ring as the scope sees it, then again with a known capacitor clipped across the switch. comes out of the two…