Inductor Value for Boost Regulator (DCM) Calculator

Critical Inductance of Boost DCM Formula:

\[ L_{x(bo\_dcm)} = \frac{(V_{i(bo\_dcm)}^2) \times (D_{bo\_dcm}^2) \times t_{c(bo\_dcm)}}{2 \times (V_{o(bo\_dcm)} - V_{i(bo\_dcm)}) \times i_{o(bo\_dcm)}} \]

Input Voltage of Boost DCM (Vi(bo_dcm)):

Duty Cycle of Boost DCM (Dbo_dcm):

Time Commutation of Boost DCM (tc(bo_dcm)):

Output Voltage of Boost DCM (Vo(bo_dcm)):

Output Current of Boost DCM (io(bo_dcm)):

Critical Inductance of Boost DCM (Lx(bo_dcm)):

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1. What is the Critical Inductance of Boost DCM?

Critical Inductance of Boost DCM refers to the minimum value of the inductance required in these converters to maintain discontinuous current flow through the inductor. It ensures proper operation in discontinuous conduction mode (DCM).

2. How Does the Calculator Work?

The calculator uses the Critical Inductance formula:

\[ L_{x(bo\_dcm)} = \frac{(V_{i(bo\_dcm)}^2) \times (D_{bo\_dcm}^2) \times t_{c(bo\_dcm)}}{2 \times (V_{o(bo\_dcm)} - V_{i(bo\_dcm)}) \times i_{o(bo\_dcm)}} \]

Where:

\( V_{i(bo\_dcm)} \) — Input Voltage of Boost DCM (V)
\( D_{bo\_dcm} \) — Duty Cycle of Boost DCM (-)
\( t_{c(bo\_dcm)} \) — Time Commutation of Boost DCM (s)
\( V_{o(bo\_dcm)} \) — Output Voltage of Boost DCM (V)
\( i_{o(bo\_dcm)} \) — Output Current of Boost DCM (A)

Explanation: This formula calculates the minimum inductance required to maintain discontinuous current mode operation in a boost converter, ensuring proper switching behavior and efficiency.

3. Importance of Critical Inductance Calculation

Details: Accurate inductance calculation is crucial for designing efficient boost converters operating in DCM. It affects switching performance, ripple current, and overall converter stability.

4. Using the Calculator

Tips: Enter all values in appropriate units. Ensure output voltage is greater than input voltage for valid calculation. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is Discontinuous Conduction Mode (DCM)?
A: DCM is an operating mode where inductor current falls to zero during each switching cycle, resulting in discontinuous current flow.

Q2: Why is critical inductance important in DCM?
A: Critical inductance ensures the converter operates in true DCM, preventing continuous conduction and maintaining desired switching characteristics.

Q3: What happens if inductance is below critical value?
A: The converter may enter continuous conduction mode (CCM), changing its operating characteristics and potentially affecting performance.

Q4: How does duty cycle affect critical inductance?
A: Higher duty cycles generally require smaller critical inductance values, as the squared duty cycle term in the numerator dominates.

Q5: Can this calculator be used for other converter topologies?
A: No, this specific formula is designed for boost converters operating in discontinuous conduction mode.