Legacy IPC2221 trace temperature model
Named legacy IPC2221 curve-fit used by DigiKey/KiCad9.0, not IPC2152. Actual width/thickness in square mils and supplied resistivity; geometry held fixed.
- Runs in your browser
- No upload
- Check before download
Named legacy IPC2221 curve-fit used by DigiKey/KiCad9.0, not IPC2152. Actual width/thickness in square mils and supplied resistivity; geometry held fixed. It omits layout, planes, airflow and thermal feedback. No PCB thermal/production certification.
Model, grammar and limits
IPC2221: I=kΔT^0.44A^0.725; A in mil², kext=.048, kint=.024
Numbers can have up to 48 characters, with a decimal point or scientific e, and no thousands separators. Voltage is generally 60 V or less; the 555 timer accepts 4.5 to 16 V. R is 1e−9 to 1e12 Ω (555: 1 to 1e9), C is 1e−18 to 100 F (555: at least 1 pF), and L is 1e−12 to 1e6 H. Curves use 2 to 501 samples, plus up to 502 cutoff and resonance points. Networks have up to 32 nodes and depth 8, with positive R only. Boolean expressions take 2 to 6 variables, 4096 characters, 1024 tokens, 512 AST nodes, depth 32, 64 rows, 729 cubes and 200000 search nodes; up to 16 ties are shown. LEDs: 1 to 100. Wire current: up to 1000 A, with your own linear temperature from −100 to 500 °C. These numeric bounds never certify that a design is physically suitable.
Values are converted to SI units and use explicit circuit layouts and ideal models. Results show up to 10 significant digits; CSV keeps the numeric values and units. A Boolean minimum is exact only when the bounded search finishes and all required (non-don't-care) rows check out. CODATA 2022 μ0 and ε0 are rounded measured constants with an uncertainty, not exact definitions; c = 299792458 m/s is exact. Nothing here is an approval for hardware, critical systems, installations or production.
Everything runs in a local worker with a 15-second time limit. Editing, resetting, canceling or leaving the page stops pending work. Inputs are never saved or uploaded automatically. An input backup is only made when you ask, up to 1 MiB, and your original files stay untouched. Input data, formulas and filenames are never sent. Only with your optional consent, Refentra sends aggregate counts of actions and outcomes, without input content.
Use this model
- Own inputs
Named legacy IPC2221 curve-fit used by DigiKey/KiCad9.0, not IPC2152. Actual width/thickness in square mils and supplied resistivity; geometry held fixed. It omits layout, planes, airflow and thermal feedback. No PCB thermal/production certification.
- Model, grammar and limits
IPC2221: I=kΔT^0.44A^0.725; A in mil², kext=.048, kint=.024 Values are converted to SI units and use explicit circuit layouts and ideal models. Results show up to 10 significant digits; CSV keeps the numeric values and units. A Boolean minimum is exact only when the bounded search finishes and all required (non-don't-care) rows check out. CODATA 2022 μ0 and ε0 are rounded measured constants with an uncertainty, not exact definitions; c = 299792458 m/s is exact. Nothing here is an approval for hardware, critical systems, installations or production.
- Download CSV report
Everything runs in a local worker with a 15-second time limit. Editing, resetting, canceling or leaving the page stops pending work. Inputs are never saved or uploaded automatically. An input backup is only made when you ask, up to 1 MiB, and your original files stay untouched. Input data, formulas and filenames are never sent. Only with your optional consent, Refentra sends aggregate counts of actions and outcomes, without input content.
Questions and model limits
Which assumptions apply?
Named legacy IPC2221 curve-fit used by DigiKey/KiCad9.0, not IPC2152. Actual width/thickness in square mils and supplied resistivity; geometry held fixed. It omits layout, planes, airflow and thermal feedback. No PCB thermal/production certification.
How exact are the results?
Values are converted to SI units and use explicit circuit layouts and ideal models. Results show up to 10 significant digits; CSV keeps the numeric values and units. A Boolean minimum is exact only when the bounded search finishes and all required (non-don't-care) rows check out. CODATA 2022 μ0 and ε0 are rounded measured constants with an uncertainty, not exact definitions; c = 299792458 m/s is exact. Nothing here is an approval for hardware, critical systems, installations or production.
What inputs are supported?
Numbers can have up to 48 characters, with a decimal point or scientific e, and no thousands separators. Voltage is generally 60 V or less; the 555 timer accepts 4.5 to 16 V. R is 1e−9 to 1e12 Ω (555: 1 to 1e9), C is 1e−18 to 100 F (555: at least 1 pF), and L is 1e−12 to 1e6 H. Curves use 2 to 501 samples, plus up to 502 cutoff and resonance points. Networks have up to 32 nodes and depth 8, with positive R only. Boolean expressions take 2 to 6 variables, 4096 characters, 1024 tokens, 512 AST nodes, depth 32, 64 rows, 729 cubes and 200000 search nodes; up to 16 ties are shown. LEDs: 1 to 100. Wire current: up to 1000 A, with your own linear temperature from −100 to 500 °C. These numeric bounds never certify that a design is physically suitable.
Where do calculations run?
Everything runs in a local worker with a 15-second time limit. Editing, resetting, canceling or leaving the page stops pending work. Inputs are never saved or uploaded automatically. An input backup is only made when you ask, up to 1 MiB, and your original files stay untouched. Input data, formulas and filenames are never sent. Only with your optional consent, Refentra sends aggregate counts of actions and outcomes, without input content.