The internal oscillator uses a timing capacitor (C_CT) and a timing resistor (R_RT) to program the oscillator frequency and maximum duty cycle. The operating frequency can be programmed based the curves in Figure 7-1, where the timing resistor can be found once the timing capacitor is selected. It is best for the timing capacitor to have a flat temperature coefficient, typical of most COG or NPO type capacitors. For this converter, 15.4 kΩ and 1000 pF were selected for R_RT and C_CT to operate at 110-kHz switching.