For device versions with SSC enabled, the switching frequency is randomly changed in PWM mode when the internal clock is used. The frequency variation is typically between the nominal switching frequency and up to 288 kHz above the nominal switching frequency. When the device is externally synchronized by applying a clock signal to the MODE/SYNC pin, the TPS6281x-Q1 follows the external clock and the internal spread spectrum block is turned off. SSC is also disabled during soft start.