The TPS563249 uses D-CAP3 (Direct Control with Adaptive On-Time, 3rd generation) control topology. D-CAP3 is an adaptive constant on-time control with a virtual inductor current ripple emulator and internal compensation. The on-time is inversely proportional to VIN and directly proportional to VOUT, maintaining approximately 1.4MHz switching frequency. The internal ripple injection circuit adds a synthetic ramp to the FB pin signal, providing the PWM ramp without requiring output voltage ripple. This allows the use of very low-ESR ceramic output capacitors while maintaining stability. The error amplifier in D-CAP3 provides DC accuracy with internal Type-2 compensation that covers a wide range of L-C output filter values. In FCCM, the low-side MOSFET is always driven, allowing negative inductor current at light loads and maintaining constant frequency. The peak current limit comparator monitors the high-side FET current each cycle. When the current limit is exceeded for 128 consecutive cycles, hiccup-mode protection disables switching for a recovery period, limiting average power dissipation during faults.