There is a trade off between higher and lower switching frequencies. Higher switching frequencies can produce a smaller 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 decreases efficiency and impacts thermal performance. In this design, a moderate switching frequency of 1.2 MHz that achieves both a small solution size and a high efficiency operation is selected. TPS542A50 offers seven choices of switching frequency in Table 7-1. RFSET equals to 47.5 kΩ for 1.2-MHz switching frequency.