If other frequencies are desired, within the frequency range of 200 kHz to 800KHz, the RFREQ (R6) resistor value can be changed. Consult the data sheet for proper selection of the RFREQ resistor. Change the inductor (L1) and the total output capacitance for proper control-loop operation. The FREQ/SYNC pin can also be used to synchronize the internal oscillator to an external clock. The TPS25868EVMQ1-162 allows users to synchronize the internal oscillator to both Lo-Z clock source and Hi-Z clock source. See the data sheet for detailed information.