A phase locked loop is used to synchronize the switching frequency of a high frequency switching power converter to a clock signal. A switching power converter integrated circuit is a tile-based power management unit and includes an oscillator and multiple tiles of switching power converters. The oscillator generates a clock signal having a clock frequency. A first switching power converter includes a switch and a phase locked loop and switches at a first frequency. The switch has a gate that receives a gate signal. The phase locked loop synchronizes the first frequency to a first integer multiple of the clock frequency. A second switching power converter switches at a second frequency that is a second integer multiple of the clock frequency. The first frequency is synchronized to a multiple of the clock frequency when a second edge of the gate signal coincides with a first edge of the clock signal.