The TPSM5D1806 can also be synchronized to an external clock that is within ±20% of the switching frequency set by the MODE2 pin. The external clock signal can be applied to the SYNC pin before or after powering up. When the device is synchronized to an external clock signal, if the clock signal is removed, the device transitions to an intermediate frequency which is 75% of the programmed frequency for approximately eight clock cycles. After eight clock cycles, the device transitions to the switching frequency set by the MODE2 pin.