1. What is ESR (Equivalent Series Resistance)?

Definition: ESR represents the effective series resistance of a capacitor at a specific frequency, combining all losses into a single resistance value.

Purpose: It helps engineers evaluate capacitor performance, especially in high-frequency applications where losses become significant.

2. How Does the ESR Calculator Work?

The calculator uses the formula:

Where:

• \( ESR \) — Equivalent Series Resistance (ohms)
• \( \delta \) — Loss tangent (dimensionless)
• \( f \) — Frequency (Hz)
• \( C \) — Capacitance (farads)

Explanation: The loss tangent represents the dielectric loss, which when divided by the capacitive reactance gives the equivalent resistance.

3. Importance of ESR Calculation

Details: ESR affects power loss, heat generation, and filtering effectiveness in circuits. Lower ESR is generally better for most applications.

4. Using the Calculator

Tips: Enter the loss tangent (from datasheet), operating frequency, and capacitance. All values must be > 0 (except loss tangent can be 0).

5. Frequently Asked Questions (FAQ)

Q1: What is a typical loss tangent value?
A: For ceramic capacitors it's 0.001-0.05, electrolytics 0.1-0.3, and film capacitors 0.0001-0.001.

Q2: Why does frequency affect ESR?
A: Because dielectric losses and electrode resistance vary with frequency.

Q3: How does ESR impact circuit performance?
A: High ESR causes power loss, heating, and reduced filtering effectiveness.

Q4: When is low ESR important?
A: In switching power supplies, RF circuits, and high-current applications.

Q5: Can ESR be measured directly?
A: Yes, with an LCR meter or by analyzing the capacitor's impedance curve.