1. What is Critical Inductance?

Critical Inductance refers to the minimum value of the inductance required in buck regulator converters to maintain continuous conduction mode (CCM) or continuous current flow through the inductor.

2. How Does the Calculator Work?

The calculator uses the Critical Inductance formula:

Where:

• \( L_x \) — Critical Inductance (Henry)
• \( D \) — Duty Cycle (0 to 1)
• \( R \) — Resistance (Ohm)
• \( f \) — Frequency (Hertz)

Explanation: The formula calculates the minimum inductance value required to maintain continuous current conduction in a buck regulator circuit.

3. Importance of Critical Inductance

Details: Maintaining continuous conduction mode is crucial for buck regulator efficiency, output voltage stability, and reducing output voltage ripple. The critical inductance value ensures smooth current flow through the inductor.

4. Using the Calculator

Tips: Enter duty cycle (0 to 1), resistance in ohms, and frequency in hertz. All values must be valid (duty cycle between 0-1, resistance > 0, frequency > 0).

5. Frequently Asked Questions (FAQ)

Q1: What happens if inductance is below critical value?
A: The circuit enters discontinuous conduction mode (DCM), leading to higher output voltage ripple and reduced efficiency.

Q2: How does duty cycle affect critical inductance?
A: Higher duty cycles result in lower critical inductance requirements, while lower duty cycles require higher inductance values.

Q3: What is the relationship between frequency and critical inductance?
A: Higher switching frequencies allow for smaller critical inductance values, enabling more compact inductor designs.

Q4: How does load resistance affect critical inductance?
A: Higher load resistance increases the critical inductance requirement, while lower resistance decreases it.

Q5: Is critical inductance the same for all converter topologies?
A: No, different converter topologies (buck, boost, buck-boost) have different critical inductance formulas and requirements.