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Power Electronics & High-Current

Motor drivers, H-bridges, high-current switching FETs, battery paths. Here the enemies are heat, current density, and switching noise β€” and sometimes mains/high voltage, which is a safety matter.

Copper & thermal​

  • Width = current. Size traces (or use copper pours) for the current; use an online trace-width calculator and add margin.
  • Use heavier copper (2 oz+) for high-current layers if needed.
  • Spread heat with polygon pours and thermal vias under hot parts (FETs, regulators).
  • Keep high-current paths short and direct; avoid thin necks at pads.

Switching FETs & gate drive​

  • Keep the gate-drive loop small (driver β†’ gate β†’ source return) β€” long gate traces ring and slow switching.
  • Add a gate resistor to tune edge speed / reduce ringing.
  • Keep the power loop (FET + bulk cap) tight; place decoupling/bulk caps close.
  • Add current sense (shunt + Kelvin connection) where you need feedback.

Isolation, creepage & clearance​

  • For higher voltages, respect creepage (along surface) and clearance (through air) per the standard for your voltage β€” widen gaps, add slots.
  • Keep high-voltage and low-voltage / logic domains physically separated.

Snubbers & protection​

  • Add snubbers / flyback diodes across inductive loads (motors, relays, solenoids).
  • Protect the input and outputs (TVS, fuses) for real-world transients.
Safety

Power electronics get hot and can carry dangerous voltages/currents. Verify thermal and clearance before powering. Treat anything mains-connected as a safety-critical design β€” see Lab Rules & Safety.

See also​