Standard Crystal Oscillators (XO) Diodes Incorporated Standard Crystal Oscillators (XO) feature low jitter and tight stability with quartz crystal resonators. These oscillators are available with CMOS / TTL, LVPECL, or LVDS output logic and have an overall accuracy of ±20ppm. Diodes Incorporated Standard Crystal Oscillators are ideal for Wi-Fi®, WiMax, PON, and telecommunications standards like SONET / SDH.