3 Load Step Calculator

The Load Step Calculator enables the user to estimate the minimum required output capacitance to meet certain load transient requirement for power supplies that use current mode control or voltage mode control schemes.

Figure 3-1 Load Step Calculator Window

Current Mode Control (CMC):

Equation 8.

C_{o u t} = \frac{1}{2 \times π \times f_{c o} \times (\frac{{∆ V}_{o u t}}{{∆ I}_{t r a n}} - E S R) \times \sqrt{2 - 2 \times \cos (\frac{P M \times π}{180 °})}}

Voltage Mode Control (VMC):

Equation 9.

C_{o u t} = \frac{1}{2 \times π \times f_{c o} \times (\frac{1}{\frac{{∆ I}_{t r a n}}{{∆ V}_{o u t}} - \frac{1}{2 \times π \times f_{c o} \times L}} - E S R) \times \sqrt{2 - 2 \times \cos (\frac{P M \times π}{180 °})}}