E.07PCB Trace Current Capacity
Calculate the trace width needed for a current, or the current a trace can carry.
Results
- Trace width
- —
- Current
- —
- Cross-section
- —
- Resistance
- —
- Voltage drop
- —
- Power loss
- —
Formulas
- IPC-2221
- I = k · ΔT^0.44 · A^0.725 (A: mil², k: external 0.048 · internal 0.024)
- Resistance
- R = ρ_Cu · (1 + 0.00393·(T − 20)) · L / (w · t)
IPC-2221 or IPC-2152?
This tool uses the widely used IPC-2221 curve-fit formula. The newer IPC-2152 standard is based on measured charts and modifiers such as board thickness and nearby copper planes; it usually allows narrower internal traces than IPC-2221, so these results are generally on the safe side.
Resistance and voltage drop are calculated assuming a trace temperature of 25 °C + ΔT.
References
- IPC-2221: Generic Standard on Printed Board Design
- IPC-2152: Standard for Determining Current Carrying Capacity in Printed Board Design
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