The LM22678 device incorporates a floating high-side gate driver to control the power MOSFET. The supply for this driver is the external bootstrap capacitor connected between the BOOT pin and SW. A good quality 10-nF ceramic capacitor must be connected to these pins with short, wide PCB traces. One reason the regulator imposes a minimum off-time is to ensure that this capacitor recharges every switching cycle. A minimum load of about 5 mA is required to fully recharge the bootstrap capacitor in the minimum off-time. Some of this load can be provided by the output voltage divider, if used.