The research and realization of the GPS module tame the local VCXO

In the design of time calibrator, time calibrator can be achieved on a higher stability, because of the highest stability of constant-temperature crystal oscillator highest stability, but as time goes on, the stability and the frequency stability of constant-temperature crystal oscillator will gradually decline, it will affect the measurement accuracy. In light of the above issues, we purpose a new method to obtain higher stability for it long time work. First, generate the frequency signal by voltage-controlled constant-temperature crystal oscillator; Second, get the signal 1S from the time GPS module; Third, comparison the above tow signals, thus, a error signal is generated; Finally, converter the error signal by digital-to-analog module, and then, use it to control the voltage-controlled constant-temperature crystal oscillator to achieve the purpose of automatic tame.