I. V. Khomenkо, A. V. Kosykh, V.P. Meyer
The article deals with increase of temperature stability of quarts oscillator frequency using methods of temperature compensation. The principal causes restraining growth of stability of oscillator frequency faced by manufacturers in application of analog temperature compensation are specified. Results of research on application of digital temperature compensation of frequency departure in quartz oscillators are given. The important advantage of a digital way is the opportunity of automation of labour-intensive processes on temperature compensation adjustment of generators frequency. Synthesis of compensating function is realized by tabular way with approximation.
Synthesis of compensating function is realized by tabular way with approximation. The formed codes values of ADC and DAC are received during the automated measurements. The design and parameters of samples of small-sized oscillators with a microcontroller for compensation of frequency temperature deviations are described. Frequency departures in a range of temperatures -40 ºС … +70 ºС is no more than ± 0,5 ppm. Power consumption is less than 50 мВт. Spectral density of phase noise of output signal is Sφ(100 Hz) ≤ 130 dBm/ Hz, Sφ(1 kHz) ≤ −145 dBm/Hz. In the paper the information on design of the prototype of automated adjustment system of temperature compensation with software is given.
The authors have proved the possibility of making low-noise desk-size oscillators with stabilized frequency and digital temperature compensation. Because of high-quality characteristics they may have high competitiveness in the world market.