8.3.19 Turn-On Behavior

Minimum on-time specification determines the maximum operating frequency of the design. As the unit starts up and goes through its soft-start process, the required duty-cycle is less than the minimum controllable on-time. This can cause the converter to skip pulses. Thus, instantaneous output pulses can be higher or lower than the desired voltage. This behavior is only evident when operating at high frequency with high bandwidth. When the minimum on-pulse is greater than the minimum controllable on-time, the turn-on behavior is normal. When operating at low frequencies (100 kHz or less), the turn-on behavior does not exhibit any ringing at initial startup.