Voltage Drop Formula:
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Definition: This calculator estimates the voltage drop across a conductive trace based on current, material resistivity, trace length, and cross-sectional area.
Purpose: It helps electrical engineers and PCB designers ensure proper voltage levels throughout a circuit by accounting for resistive losses.
The calculator uses the formula:
Where:
Explanation: The voltage drop is calculated by multiplying the current by the trace resistance, which is determined by the material properties and geometry.
Details: Proper voltage drop estimation ensures signal integrity, adequate power delivery, and prevents excessive power loss in traces.
Tips: Enter the current in amps, material resistivity (default 1.68×10⁻⁸ Ω·m for copper), trace length in meters, and cross-sectional area in square meters. All values must be > 0.
Q1: What's a typical resistivity value for copper?
A: Pure copper at 20°C has ρ ≈ 1.68×10⁻⁸ Ω·m. This increases with temperature (about 0.4% per °C).
Q2: How do I calculate cross-sectional area?
A: For rectangular traces: width × thickness. For circular traces: π × (radius)².
Q3: What's an acceptable voltage drop?
A: Typically less than 3-5% of supply voltage, but depends on application requirements.
Q4: Does this account for temperature effects?
A: No, for high-temperature applications, adjust resistivity accordingly.
Q5: How can I reduce voltage drop?
A: Increase trace width/thickness (area), use shorter traces, or choose lower resistivity materials.