Q. What is the application of X'tal and oscillator?     A. Crystal Digital camera, wireless, computers, interface cards, telephones, pagers, remote controllers, GPS, A/V products. Oscillator Wireless, computers, GPS, A/V products, etc. VCXO Modems, ADSL, wireless base stations, switching equipment, etc. TCXO/VCTCXO Cell phones, wireless base stations, precision apparatus, GPS, etc. Saw Filter Wireless transceiver, cell phones, etc.     Q. What is the "AT-CUT" ?     A. A plate cut from a crystal of quartz in such a way that the plate contains the X-axis and makes an angle of about 35 1/4¢Xwhich the optic axis on the r side.     Q. What is the "Spurious mode" ?     A. One of the undesired modes of vibration of a piezoid. Usually refers to one of the inharmonic overtone modes. (Spur-Contraction of spurious mode)     Q. What is the "Jitter" and it's significance?     A. Jitter is short-term variations of the significant instants of a digital signal from their ideal positions in time. The expected edges in a digital datastream never occur exactly where desired. Defining and measuring the timing accuracy of those edges (jitter) is critical to the performance of synchronous communication systems.