9.2.2 Detailed Design Procedure

When the switch is enabled, the output capacitors must be charged up from 0 V to the set value (3.3 V in this example). This charge arrives in the form of inrush current. Inrush current can be calculated using Equation 2:

The TPS22966-Q1 offers adjustable rise time for VOUT. This feature allows the user to control the inrush current during turnon. The appropriate rise time can be calculated using Table 3 and the inrush current equation.

To ensure an inrush current of less than 400 mA, choose a CT value that will yield a rise time of more than 181.5 μs. See the oscilloscope captures in for an example of how the CT capacitor can be used to reduce inrush current.