Only the loop controller device needs a resistor divider at the MSEL1 pin to program USER_DATA_01 (COMPENSATION_CONFIG) and FREQUENCY_SWITCH. The MSEL1 pin of secondary channels are not used. In this design, a moderate switching frequency of 650 kHz achieves both a small design size and a high-efficiency operation. Use the MSEL1 pin program table to select the frequency option. See Table 8-8 for resistor divider code selection. With 650-kHz switching frequency, a single resistor to AGND can be used to program compensation settings 19. To program all 32 compensation settings possible through MSEL1, resistor divider code 9 sets the switching frequency to 650 kHz.