*3.3. Stress on Semiconductor Devices*

The current stress values on active and passive switches are computed using the Equations (5)–(7). The current stress on *S*1, *DS*<sup>1</sup> , *S*2, and *DS*<sup>2</sup> are:

$$\begin{aligned} I\_{S\_1} = I\_{D\_{S1}} &= \frac{E[2L\_1 f\_s + DR(1 - D)^4)}{2\mathcal{R}(1 - D)^4 L\_1 f\_s} \\\\ I\_{S\_2} = I\_{D\_{S2}} &= \frac{E[2L\_2 f\_s + DR(1 - D)^2]}{2\mathcal{R}(1 - D)^3 L\_2 f\_s} \end{aligned} \tag{12}$$

Using the Figure 5, the voltage stress values on active and passive switches are computed as:

$$\begin{aligned} V\_{\mathbb{S}\_1} &= -V\_{D\_{\mathbb{S}1}} = V\_0(1 - D) \\\\ V\_{\mathbb{S}\_2} &= -V\_{D\_{\mathbb{S}2}} = V\_0 \end{aligned} \tag{13}$$

The Equation (13) shows that the voltage stress on *S*<sup>1</sup> and *DS*<sup>1</sup> increases when the duty cycle is reduced. The stress on *S*<sup>2</sup> and *DS*<sup>2</sup> does not depend on the duty cycle.
