1. What is JLCPCB Microstrip Impedance?

The JLCPCB microstrip impedance formula calculates the characteristic impedance of a PCB trace on a dielectric substrate. This is crucial for designing high-frequency circuits where impedance matching is important for signal integrity.

2. How Does the Calculator Work?

The calculator uses the JLCPCB microstrip impedance formula:

Where:

• \( Z \) — Characteristic impedance (Ω)
• \( \epsilon_r \) — Relative permittivity of the substrate (unitless)
• \( h \) — Substrate height (mm)
• \( w \) — Trace width (mm)

Explanation: The equation accounts for the relationship between trace geometry, substrate properties, and resulting impedance.

3. Importance of Impedance Calculation

Details: Accurate impedance calculation is crucial for PCB design to ensure proper signal transmission, minimize reflections, and maintain signal integrity in high-frequency applications.

4. Using the Calculator

Tips: Enter substrate relative permittivity (ε_r), height (h) in mm, and trace width (w) in mm. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is typical impedance for PCB traces?
A: Common values are 50Ω for RF systems and 75Ω for video applications, though specific designs may vary.

Q2: How accurate is this formula?
A: This provides a good estimate for standard microstrip configurations but may have limitations for very wide or narrow traces.

Q3: What affects microstrip impedance?
A: Trace width, substrate height, and dielectric constant are primary factors. Copper thickness has minor effect.

Q4: When should I use this calculator?
A: When designing PCB traces for high-frequency signals where impedance control is important.

Q5: Are there limitations to this formula?
A: It works best for standard PCB geometries. For complex cases or edge-coupled traces, more sophisticated models may be needed.