Vibrating mechanical devices for frequency reference or selection are likely the main bottleneck of fully-integrated electronic systems. Currently, quartz crystals are used for most high performance systems but not economical when integrating with system IC’s due to costly hermetic packaging requirements. With MEMS, vibrating mechanical devices and wafer level vacuum packages can be manufactured with conventional semiconductor technologies. This class highlights the shift from Quartz to MEMS elaborating on ways designers optimize products saving time and money.