US Patent 7813410 Initiating spread spectrum modulation

An apparatus and a method to initiate spread spectrum modulation have been presented. In one embodiment, a spread spectrum off to spread spectrum on transition circuit is used to start spread spectrum modulation. The spread spectrum off to spread spectrum on transition circuit may include a phase lock loop (PLL) to output a clock signal. The spread spectrum off to spread spectrum on transition circuit may further include a control block coupled to the PLL to cause the PLL to lock the clock signal to a predetermined center frequency before transitioning from a non-spread spectrum mode into a spread spectrum mode.