Crystal oven

About: Crystal oven is a research topic. Over the lifetime, 955 publications have been published within this topic receiving 10380 citations. The topic is also known as: oven-controlled crystal oscillator & OCXO.

A Comparison of Frequency Pullability in Oscillators Using a Single AT-Cut Quartz Crystal and Those Using Two Single AT- Cut Crystals Connected in Parallel with a Series Load Capacitance or Series Load Inductance

Abstract: This paper presents a comparison of frequency pullability in oscillators using asingle AT-cut crystal and those using two single AT-cut crystals connected in paralleloperated with a series load capacitance or series load inductance at fundamental frequenciesof 4, 10 and 19 MHz. Pullability describes how the operating frequency may be changed byvarying the load capacitance. The paper also gives impedance circuits for both single- anddual-crystal units. The experiment results show that the new approach using two singlequartz crystals connected in parallel increases the frequency pulling range by 30-200% pending on the type of oscillator. Also given is the crystal frequency stability at thesethree frequencies.

A study of low-power crystal oscillator design

Abstract: UWB backscatter RFID systems require high quality clock signals and crystal oscillator is one of the few candidates. A study of a low-power parallel-mode crystal oscillator for such applications is presented. A 7.8125 MHz Pierce crystal oscillator is realized in a TSMC 90 nm CMOS process. It has a frequency stability of ±7 ppm from 0 to 70°C and draws 36 μW from a 1.2 V supply. The core area excluding pads is 0.021 mm2.

Electronic timepiece utilizing main oscillator circuit and secondary oscillator circuit

Abstract: An electronic timepiece having a main oscillator circuit including a first quartz crystal vibrator as a time standard and also having a secondary oscillator circuit including a further quartz crystal vibrator as a time standard for reducing the affect of temperature on the accuracy of the timepiece by utilizing the different temperature characteristics of the respective time standards is provided. The main oscillator circuit produces a high frequency time standard signal having a first frequency rate that is determined, at least in part, by the temperature characteristic of the first time standard, which characteristic includes an inflection peak at a specific temperature. The second oscillator circuit produces a second high frequency time standard signal having a second predetermined frequency, determined, at least in part, by the temperature characteristic of the second time standard being distinct from that of the first time standard. Phase detection circuitry is provided for producing a phase detection signal in response to detecting a predetermined frequency difference in phase between the first and second high frequency time standard signals when the temperature is 10° higher or lower than the specific temperature at which the first time standard has its inflection peak. A display is provided for displaying actual time in response to receiving a low frequency time signal produced by divider circuitry. A frequency adjustment circuit is coupled intermediate the phase detection circuitry and the divider circuitry for adjusting the frequency of the low frequency time signal produced by the divider circuitry when a phase detection signal is applied thereto.

A Frequency-Lock System for Improved Quartz Crystal Oscillator Performance

Abstract: The intrinsic noise of the best quartz crystal resonators is significantly less than the noise observed in oscillators employing these resonators Several problem areas common to traditional designs are pointed out and a new approach is suggested for their solution. Two circuits are described which frequency lock a spectrally pure quartz crystal oscillator to an independent quartz crystal resonator. The performance of the composite system is predicted based on the measured performance of its components.