Figure 9-28 shows the schematic diagram of a dual-phase synchronous buck regulator with output voltage of 3.3 V and a rated load current of 20 A. In this example, the target half-load and full-load efficiencies are 95% and 92%, respectively, based on a nominal input voltage of 12 V that ranges from 4 V to 36 V. The switching frequency is set at 400 kHz by resistors R_RT1 and R_RT2.