1. What is the PCB Trace Max Current Equation?

The PCB Trace Max Current equation estimates the maximum current a copper trace can carry without exceeding a specified temperature rise. It's essential for designing reliable printed circuit boards.

2. How Does the Calculator Work?

The calculator uses the equation:

Where:

• \( I_{max} \) — Maximum current (Amperes)
• \( k \) — Constant (typically 0.048 for outer layers, 0.024 for inner layers)
• \( \Delta T \) — Temperature rise above ambient (°C)
• \( A \) — Cross-sectional area of the trace (mm²)

Explanation: The equation accounts for the relationship between current carrying capacity, temperature rise, and trace dimensions.

3. Importance of Trace Current Calculation

Details: Proper trace sizing prevents overheating, ensures reliability, and maintains signal integrity in PCB designs.

4. Using the Calculator

Tips: Enter the appropriate constant (k), desired temperature rise, and trace cross-sectional area. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What's a typical value for k?
A: For external traces: 0.048, for internal traces: 0.024. These values assume standard PCB materials.

Q2: What temperature rise is acceptable?
A: Typically 10-20°C for general applications, but depends on specific design requirements.

Q3: How do I calculate cross-sectional area?
A: Area = trace width (mm) × copper thickness (mm). Standard 1oz copper is 0.035mm thick.

Q4: Does this account for high frequency effects?
A: No, this is for DC/low frequency currents. High frequency designs require additional considerations.

Q5: What about multiple traces close together?
A: This calculator assumes an isolated trace. For multiple traces, derating may be necessary.