Thermally Compensated Crystal Oscillator (TCXO) oscillators are an important type of frequency control device used in many electronic products. TCXOs use a quartz crystal or ceramic resonator as the active element and employ thermistors or an electronic temperature compensation circuit to adjust the oscillation frequency so that it remains stable over changing temperature conditions. They feature excellent stability, low phase noise, wide operating temperatures and low g-sensitivities making them well suited for communication and timing applications including GPS and GSM telephones. TCXOs can also be configured in several different packages to provide numerous options for size and electrical connection.