The first step is to decide on a switching frequency for the regulator. There is a trade off between higher and lower switching frequencies. Higher switching frequencies may produce smaller a solution size using lower valued inductors and smaller output capacitors compared to a power supply that switches at a lower frequency. However, the higher switching frequency causes extra switching losses, which hurt the converter’s efficiency and thermal performance. In this design, a switching frequency of 500 kHz is selected. Based on Figure 7-4, the RT value is set to a standard value of 95.3 kΩ.