MC33262 Circuit Design Calculator











Formulas

For Peak Inductor Current (\(I_{L(pk)}\)):

\[ I_{L(pk)} = \frac{2 \times 1.414 \times P_O}{\eta \times V_{AC(LL)}} \]

For Inductance (\(L_P\)):

\[ L_P = \frac{t \left(\frac{V_O}{\sqrt{2}} - V_{AC(LL)}\right) \times \eta \times V_{AC(LL)}^2}{\sqrt{2} \times V_O \times P_O} \]

For Switch On-Time (\(t_{on}\)):

\[ t_{on} = \frac{2 \times P_O \times L_P}{\eta \times V_{AC(LL)}^2} \]

Definitions

Po: Required converter output power.

Vo: Desired output voltage.

\(\eta\): Efficiency of the converter.

Vacll: Minimum AC RMS line voltage.

Lp: Inductance.

t{on}: Switch on-time.

Example Calculation

Let's assume the following values:

Step 1: Calculate Peak Inductor Current (\(I_{L(pk)}\)):

\[ I_{L(pk)} = \frac{2 \times 1.414 \times 80}{0.92 \times 90} = 2.74 \text{ A} \]

Step 2: Calculate Inductance (\(L_P\)):

\[ L_P = \frac{40 \times 10^{-6} \left(\frac{230}{\sqrt{2}} - 90\right) \times 0.92 \times 90^2}{\sqrt{2} \times 230 \times 80} = 832.4 \mu H \]

Step 3: Calculate Switch On-Time (\(t_{on}\)):

\[ t_{on} = \frac{2 \times 80 \times 93.47 \times 10^{-6}}{0.92 \times 90^2} = 0.0174 \text{ ms} = 17.4 \mu s \]