7.5.1 Zero Crossing (ZX) Operation

The zero crossing comparator is adaptive for improved accuracy. As the output current decreases from a heavy load condition, the inductor current also reduces and eventually arrives at a valley, where it touches zero current, which is the boundary between continuous conduction and discontinuous conduction modes. The SW pin detects the zero-current condition. When this zero inductor current condition occurs, the ZX comparator turns off the rectifying MOSFET.