The TPS546D24S devices operate in continuous conduction mode (CCM) at a fixed frequency, regardless of the output current. During soft start, some of the low-side MOSFET on-times are limited to prevent excessive current sinking in the event the device is started with a prebiased output. After the first PWM pulse, and with each successive PWM pulse, this limit is increased to allow more low-side FET on-time and transition to CCM. After this transition has completed, the low-side MOSFET and the high-side MOSFET on-times are fully complementary.