1. What is PCB Power Plane Voltage Drop?

Definition: This calculator estimates the voltage drop across a PCB power plane based on current, material resistivity, and physical dimensions.

Purpose: It helps electrical engineers and PCB designers ensure proper voltage delivery across their circuit boards.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( VD \) — Voltage drop (volts)
• \( I \) — Current through the plane (amps)
• \( \rho \) — Resistivity of copper (Ω·m)
• \( L \) — Length of current path (meters)
• \( w \) — Width of power plane (meters)
• \( t \) — Thickness of copper (meters)

Explanation: The formula calculates the resistance of the power plane and multiplies it by current to determine voltage drop.

3. Importance of Voltage Drop Calculation

Details: Proper voltage drop estimation ensures components receive adequate voltage, prevents power-related issues, and maintains signal integrity.

4. Using the Calculator

Tips: Enter current in amps, resistivity (default 1.72×10⁻⁸ Ω·m for copper), length, width, and thickness (default 35μm for 1oz copper). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What's a typical acceptable voltage drop?
A: Generally less than 3% of supply voltage, but depends on application requirements.

Q2: How do I convert PCB dimensions from inches to meters?
A: Multiply inches by 0.0254 to get meters (1 inch = 0.0254 meters).

Q3: What resistivity value should I use for other materials?
A: Use 2.44×10⁻⁸ Ω·m for gold, 1.59×10⁻⁸ Ω·m for silver, or 1.68×10⁻⁸ Ω·m for annealed copper.

Q4: How does temperature affect the calculation?
A: Copper resistivity increases with temperature (~0.4% per °C). For high-temp applications, adjust ρ accordingly.

Q5: What if my power plane has multiple layers?
A: Calculate each layer separately and use parallel resistance formula for total voltage drop.