Epson also manufacturers specialty SPXOs such as spread spectrum and high stability oscillators. By using a spread spectrum oscillator, a system’s EMI levels could be reduced by -10dB to help the system pass FCC regulatory EMI testing. Spread spectrum oscillator works by spreading the energy out by modulating the frequency, instead of concentrating all the frequency reference energy on a single frequency. Epson spread spectrum oscillators are available in three sizes, twelve different spread patterns and a wide frequency range from 10MHz to 166MHz. The SG-9001CA also allows the spread spectrum function to be turned on and off to test EMI levels. Epson’s SG-211S*E and HG-2150CA high stability oscillators are unique in the ability to meet +/-15ppm frequency stability.