Calculadora de Impedancia de Pista
Impedancia microstrip y stripline
Required Parameters
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Quick Answer
Microstrip impedance depends heavily on the trace width, dielectric height (prepreg/core thickness), and the substrate's dielectric constant (Er).
Calculadora de Impedancia de Traza
Calcule la impedancia caracteristica de trazas microstrip y stripline en PCB para disenos digitales de alta velocidad y RF.
Herramientas Relacionadas
- Calculadora de Ancho de Pista PCB
- Calculadora de Reactancia
Design Notes
This calculator uses IPC-2141 analytic approximations, which are excellent for sub-GHz designs. However, for precise multi-gigabit routing (PCIe, USB 3.0, DDR4), you must rely on 2D/3D field solvers (like Si9000 or built-in Altium/KiCad solvers) and work directly with your PCB manufacturer's controlled-impedance stackup. Prepreg thickness often shrinks during pressing; always let the fab house tweak your final trace width.
Common Mistakes
- 1
Not referencing a solid, continuous ground plane directly beneath the trace (routing over splits causes huge impedance discontinuities).
- 2
Ignoring the solder mask effect: Solder mask slightly lowers the impedance of an external microstrip by 2-3 ohms.
- 3
Using generic FR4 formulas for precise 5GHz+ RF feeds without accounting for the varying Er of woven glass weaves.
Engineering Handbox
1. Apply Microstrip: Z0 = (87 / √(4.4 + 1.41)) × ln((5.98 × 0.18) / (0.8 × 0.3 + 0.035)) 2. Z0 = 36.12 × ln(1.0764 / 0.275) 3. Z0 = 36.12 × 1.364 = 49.2 Ω
Knowledge Base
¿Cuál es la impedancia típica de una pista PCB?
50Ω para señales single-ended. 75Ω para video. 90Ω/100Ω diferencial para USB, HDMI, Ethernet.
¿Diferencia entre microstrip y stripline?
Microstrip: capa externa con un plano de referencia. Stripline: capa interna entre dos planos. Stripline ofrece mejor blindaje.
¿Cuál es la constante dieléctrica del FR4?
~4.2–4.8 a 1 MHz. A frecuencias más altas (1–10 GHz): 3.8–4.2.
¿Necesito un simulador de campo?
Bajo 1 GHz: fórmulas analíticas son suficientes. Para multi-gigabit (PCIe, USB 3.0): use simulador 2D.
¿Afecta la máscara de soldadura a la impedancia?
Sí, agrega una capa dieléctrica que reduce la impedancia ~2–3 ohms.
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