2004.08.24
Nihon Dempa Kogyo Co., Ltd. (NDK), a world leader of the quartz crystal devices, has introduced a Dual Mode SC-Cut Crystal Oscillator, at the Institute of Electrical and Electronics Engineers Ultrasonics, Ferroelectrics, and Frequency Control (IEEE UFFC) held in Montreal City, Canada, from August 24 through 27, 2004.
The unveiled Crystal Oscillator uses B mode oscillation frequency for temperature regulation, which provides the temperature information of the SC-Cut quartz crystal itself. Over the temperature range of -20deg.C to +70deg.C, the temperature of the SC-Cut crystal has been locked within +/-0.002deg.C converted by the beat frequency between C and B modes. In this way a stable oscillation of C mode oscillation frequency is realized.
The technique has been known, but it was too hard to achieve a simultaneous oscillation under the wide temperature and voltage variation. Even if a thermal sensor was added as a temperature regulation, the accuracy was not improved, because of the difference in the temperature between the thermal sensor and the quartz crystal. However, by developing the original oscillation circuit, NDK has succeeded in creating the Dual Mode SC-Cut Crystal Oscillator.
See the major performance below:
- Temperature regulation accuracy of quartz crystal; +/-0.002deg.C / -20deg.C to +70deg.C
- High-resolution temperature regulation by using the PLD and CPU with the algorithm in software
- Simplified circuit (e.g. Eliminating the cost expensive Digital-Analog Converter (DAC) )
- Saving power consumption; less than 2.4 W / supply voltage=+12 V, temperature=+25deg.C
- High stability by single oven [previously by double oven]
Moreover, the new oscillation circuit will be able to apply other kinds of multi-mode oscillators such as fundamental, overtone, and AT-Cut crystal oscillators.
Approved the results of study and development, NDK has presented the paper at IEEE UFFC-2004.
Besides, the sales of the Crystal Oscillator will be expected as much as 4 to 5 billion yen in three years, in the market of base station for mobile communication system and routers for broadband network.
Details
| 1) | CONFERENCE | : IEEE UFFC-2004 (URL: http://www.ieee-uffc.org/UFFC-2004/) |
| 2) | DATE | : August 24-27, 2004 |
| 3) | LOCATION | : Montreal City, CANADA |
| 4) | PRESENTATION THEME : | |
| (1) | Development Goal | |
| To develop high-stability crystal oscillator which has stabilized temperature in oven by using B mode oscillation frequency as thermal sensor. | ||
| (2) | Announcements Contents | |
| a. Simultaneous dual mode oscillation circuit | ||
| b. Signal Extraction | ||
| c. Thermal Sources, Thermal Insulation and Temperature Regulation | ||
