The TPS61372 implements the soft start function to reduce the inrush current during start-up. The TPS61372 begins soft start when the EN pin is pulled high. There are two phases for the start-up procedure:

• When V_OUT is below 120% V_IN, the output votlage ramps up with the switching frequency of 535 kHz (typical).
• When V_OUT exceeds 120% V_IN, the switching frequency changes to 1.5 MHz typically and ramps up the output voltage to the setpoint.