A method and apparatus that generates a spread spectrum signal in a printer power supply unit is disclosed. The method may include receiving an enable signal to power on the printer power supply unit, generating an initial power signal for the printer power supply unit based on the signal received from the power supply controller, the initial power signal being generated in a predetermined frequency range around a predetermined center frequency value, powering on the printer power supply unit using the generated initial power signal, repeatedly updating the initial power signal, wherein the updated power signal has a frequency value in the predetermined frequency range and the predetermined center frequency value is maintained, and powering the printer power supply unit using the updated power signal.