Now there will be an examination of the synchronous buck converter charging the inductor. When Q1 is on and Q2 is off, current is allowed to flow through the inductor and charge the output capacitor while transferring energy to the load. With the phase node high, the graphs on the bottom show the phase node high and the output voltage rising. Since the capacitor has charged and energy is stored in the inductor, the power supply is ready to turn off Q1 and turn on Q2. In the non-synchronous case, a diode would replace Q2, and current would not be allowed to flow through the diode either, so the behavior of the circuit is similar.