Motor Driver Trace Width Calculator
Phase-trace copper for 5 A drivers sized for stall, not cruise — with Kelvin-sense and loop-area layout rules.
Preset for this niche — adjust to your stack-up. IPC-2221 assumes still air; verify hot paths with a thermal camera.
Motor Driver Trace Width Calculator computes phase-trace copper for motor drivers, sized for stall rather than cruise — free, instant and private in your browser. Robotics and CNC builders laying out stepper/BLDC driver boards use it to skip the datasheet algebra: type your numbers, read the answer with the substituted formula shown step by step, and share an exact permalink of the calculation.
About Motor Driver Trace Width Calculator
Motor Driver Trace Width Calculator computes phase-trace copper for motor drivers, sized for stall rather than cruise using the standard engineering relation: IPC-2221 with driver presets: 5 A, 20 °C rise, 2 oz copper. Worked live: 5 A phases want ~2.3 mm on 2 oz copper — and a jammed rotor doubles the current until protection reacts. The result recalculates on every keystroke, the worked-example panel shows your numbers substituted into the formula, and the Copy permalink button encodes the inputs in the URL so a colleague opens exactly your calculation. Everything runs client-side — nothing you type leaves your device.
How to use Motor Driver Trace Width Calculator
- 1Enter your values — the tool starts with realistic defaults for this exact use case, so the worked example is meaningful immediately.
- 2Read the live result and the worked-example panel, which substitutes your numbers into the formula step by step.
- 3Adjust any input to compare scenarios, then use Copy result or Copy permalink to share the calculation.
Why use Motor Driver Trace Width Calculator?
- ✓Implements the real formula — IPC-2221 with driver presets: 5 A, 20 °C rise, 2 oz copper — with the substitution shown, not a black box
- ✓Built for robotics and CNC builders laying out stepper/BLDC driver boards
- ✓Copy result and permalink buttons — share the exact calculation in a README, forum answer or design review
- ✓100% free, no sign-up, runs entirely in your browser (works offline once loaded)
Frequently asked questions
How do you calculate motor driver trace width?+
Phase-trace copper for motor drivers, sized for stall rather than cruise follows IPC-2221 with driver presets: 5 A, 20 °C rise, 2 oz copper. For example, 5 A phases want ~2.3 mm on 2 oz copper — and a jammed rotor doubles the current until protection reacts. The calculator applies the same relation and shows the substituted arithmetic so you can verify every step.
Why route motor phase pairs side by side?+
The out-and-return currents cancel magnetically when adjacent, shrinking the loop antenna your PWM edges would otherwise drive. Separated phase traces are the #1 cause of driver boards that pass bench tests and fail EMC — or corrupt their own current sensing.
My current readings are nonsense though the motor runs — why?+
Shared milliohms: the shunt's sense path borrows trace carrying load current, adding I·R to the tiny sense voltage. Kelvin-route two dedicated traces from the shunt pads to the amplifier carrying nothing else — the layout fix costs nothing and rescues the feedback loop.
Is the Motor Driver Trace Width Calculator free and private?+
Yes — completely free with no sign-up or usage limits, and it runs entirely in your browser: the values you enter are never uploaded or stored on a server.
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