The choice of switching frequency is a compromise between conversion efficiency and overall solution size. Lower switching frequency implies reduced switching losses and usually results in higher system efficiency. However, higher switching frequency allows the use of smaller inductors and output capacitors, hence, a more compact design. For this example, 400 kHz is used.

For designs that synchronize the switching frequency using the SYNC pin, this pin must not be left floating. To ensure that the SYNC pin has a known state, place either a pull-up or pull-down resistor depending on the desired default switching state. If a pull-up resistor is selected, ensure that the pull-up source voltage does not exceed the absolute maximum rating of the pin.