Author: S. Schodowski
Publisher:
ISBN:
Category :
Languages : en
Pages : 34
Book Description
The report describes a compensation approach based on the introduction of controlled nonlinearity into the TCXO's frequency-voltage tuning characteristic by using a pair of varactor diodes and a fixed bias source. The result is considerable simplification of the temperature-compensation process for a TCXO using a fundamental AT-cut crystal unit. The simplification comes about by transformation of portion of the classic cubic voltage correction function to a monotonic function which then can be approximated to a high degree of accuracy with one or two '3-point' network segments, using a given thermistor in each. A stability of plus or minus 5 x 10 to the minus 8th power (5 to 80C) was obtained in one case where the required monotonic compensation function was generated in two segments. In another example, a stability of plus or minus 1 x 10 to the minus 8th power was easily obtained by compensating over a plus or minus 10C range about the upper turnover temperature. (Author).
A New Approach to a High-Stability Temperature-Compensated Crystal Oscillator
Author: S. Schodowski
Publisher:
ISBN:
Category :
Languages : en
Pages : 34
Book Description
The report describes a compensation approach based on the introduction of controlled nonlinearity into the TCXO's frequency-voltage tuning characteristic by using a pair of varactor diodes and a fixed bias source. The result is considerable simplification of the temperature-compensation process for a TCXO using a fundamental AT-cut crystal unit. The simplification comes about by transformation of portion of the classic cubic voltage correction function to a monotonic function which then can be approximated to a high degree of accuracy with one or two '3-point' network segments, using a given thermistor in each. A stability of plus or minus 5 x 10 to the minus 8th power (5 to 80C) was obtained in one case where the required monotonic compensation function was generated in two segments. In another example, a stability of plus or minus 1 x 10 to the minus 8th power was easily obtained by compensating over a plus or minus 10C range about the upper turnover temperature. (Author).
Publisher:
ISBN:
Category :
Languages : en
Pages : 34
Book Description
The report describes a compensation approach based on the introduction of controlled nonlinearity into the TCXO's frequency-voltage tuning characteristic by using a pair of varactor diodes and a fixed bias source. The result is considerable simplification of the temperature-compensation process for a TCXO using a fundamental AT-cut crystal unit. The simplification comes about by transformation of portion of the classic cubic voltage correction function to a monotonic function which then can be approximated to a high degree of accuracy with one or two '3-point' network segments, using a given thermistor in each. A stability of plus or minus 5 x 10 to the minus 8th power (5 to 80C) was obtained in one case where the required monotonic compensation function was generated in two segments. In another example, a stability of plus or minus 1 x 10 to the minus 8th power was easily obtained by compensating over a plus or minus 10C range about the upper turnover temperature. (Author).
High-Stability Temperature-Compensated Crystal Oscillator Study (HSTCXO).
Author: Gayle E. Buroker
Publisher:
ISBN:
Category :
Languages : en
Pages : 79
Book Description
The objective of this study is the development of a high-stability temperature compensated crystal oscillator (HSTCXO), capable of being produced in quantity for use in advanced SSB communications equipment. This report discusses progress in the second period, including additional retrace data on the frequency-temperature characteristics of crystals, the construction and coarse compensation of two HSTCXO models, and the fabrication and satisfactory test of MOS chips designed in the first period. (Author).
Publisher:
ISBN:
Category :
Languages : en
Pages : 79
Book Description
The objective of this study is the development of a high-stability temperature compensated crystal oscillator (HSTCXO), capable of being produced in quantity for use in advanced SSB communications equipment. This report discusses progress in the second period, including additional retrace data on the frequency-temperature characteristics of crystals, the construction and coarse compensation of two HSTCXO models, and the fabrication and satisfactory test of MOS chips designed in the first period. (Author).
High Stability Temperature Compensated Crystal Oscillator Study
Author: Alan B. Mroch
Publisher:
ISBN:
Category :
Languages : en
Pages : 114
Book Description
The purpose of this program is the further development of a high stability temperature compensated crystal oscillator (HSTCXO) initially developed under contract DAAB07-71-C-0136. This HSTCXO is digitally compensated and is intended for use as a reference frequency source in advanced tactical communications systems. The program is to include detailed investigations into critical areas of size reduction, compensation simplification, and performance improvement. Five advanced exploratory models of the digitally compensated HSTCXO are to be delivered.
Publisher:
ISBN:
Category :
Languages : en
Pages : 114
Book Description
The purpose of this program is the further development of a high stability temperature compensated crystal oscillator (HSTCXO) initially developed under contract DAAB07-71-C-0136. This HSTCXO is digitally compensated and is intended for use as a reference frequency source in advanced tactical communications systems. The program is to include detailed investigations into critical areas of size reduction, compensation simplification, and performance improvement. Five advanced exploratory models of the digitally compensated HSTCXO are to be delivered.
Comparison Among Precision Temperature Compensated Crystal Oscillators
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 6
Book Description
There are different precision temperature compensated crystal oscillators showing the frequency-temperature stability better than 1x10( -6) in a very wide temperature range. To choose the suitable oscillator one should consider its frequency-temperature stability, power consumption, size, cost, phase noise and other specifications. According to a lot of experiments and comparisons, as the precision TCXO, double compensated TCXO which combines analog and digital compensation approaches together is more competitive in cost, size, stability and mass production compared with ordinary precision TCXO, DTCXO and MCXO based on AT cut crystals. It is difficult to use ordinary TCXO to get a very good frequency-temperature stability, but its repeatability can be good with suitable components and circuits, and quantization error does not exist in it. Therefore it is possible to be compensated further.
Publisher:
ISBN:
Category :
Languages : en
Pages : 6
Book Description
There are different precision temperature compensated crystal oscillators showing the frequency-temperature stability better than 1x10( -6) in a very wide temperature range. To choose the suitable oscillator one should consider its frequency-temperature stability, power consumption, size, cost, phase noise and other specifications. According to a lot of experiments and comparisons, as the precision TCXO, double compensated TCXO which combines analog and digital compensation approaches together is more competitive in cost, size, stability and mass production compared with ordinary precision TCXO, DTCXO and MCXO based on AT cut crystals. It is difficult to use ordinary TCXO to get a very good frequency-temperature stability, but its repeatability can be good with suitable components and circuits, and quantization error does not exist in it. Therefore it is possible to be compensated further.
An Improved Method of Temperature Compensation of Crystal Oscillators
Author: J. S. Wilson
Publisher:
ISBN:
Category :
Languages : en
Pages : 6
Book Description
A new method of temperature compensation of crystal oscillators has been developed. It is primarily intended for AT-cut crystal oscillators and offers advantages of higher stability, lower power consumption and smaller size compared with oscillators in current production. Compensation is achieved by generating a power series representation of the control voltage for a voltage controlled crystal oscillator. A bipolar integrated circuit has been designed which generates four voltages, each varying as a function of temperature. One voltage is constant while the others have a linear, quadratic and cubic variation with temperature. These voltages are similar in shape to the first four Chebyshev polynomials and the compensation voltage is obtained by summing the voltages in an operational amplifier. Prototype oscillators have been assembled which have a frequency tolerance of less than + or - 1ppm over the temperature band 85 deg C to -40 deg C. The current consumption of these oscillators is 1mA. (Author).
Publisher:
ISBN:
Category :
Languages : en
Pages : 6
Book Description
A new method of temperature compensation of crystal oscillators has been developed. It is primarily intended for AT-cut crystal oscillators and offers advantages of higher stability, lower power consumption and smaller size compared with oscillators in current production. Compensation is achieved by generating a power series representation of the control voltage for a voltage controlled crystal oscillator. A bipolar integrated circuit has been designed which generates four voltages, each varying as a function of temperature. One voltage is constant while the others have a linear, quadratic and cubic variation with temperature. These voltages are similar in shape to the first four Chebyshev polynomials and the compensation voltage is obtained by summing the voltages in an operational amplifier. Prototype oscillators have been assembled which have a frequency tolerance of less than + or - 1ppm over the temperature band 85 deg C to -40 deg C. The current consumption of these oscillators is 1mA. (Author).
A New Frequency Temperature Compensation Method for Oscillators
Author: T. Kudo
Publisher:
ISBN:
Category :
Languages : en
Pages : 6
Book Description
This paper describes a new frequency temperature compensation method for crystal oscillators. The method is applicable to resonators with second order or third order frequency temperature characteristics. Hence, an oscillator with an AT cut, a BT cut crystal unit or a surface acoustic wave resonator (SAWR) can be efficiently compensated. A conventional temperature compensated crystal oscillator (TCXO) uses an expensive variable capacitance diode (varactor) with good linearity as well as many thermistors. Considerable efforts have been devoted to developing a new reactance circuit to replace the varactor. It was found that a series circuit, involving a capacitor and a silicon diode, has the same characteristics as a varactor, and its linearity could be easily adjusted. In the case of an AT cut crystal unit with third order frequency temperature characteristics, compensation over a wide temperature range can be achieved by using two series circuits.
Publisher:
ISBN:
Category :
Languages : en
Pages : 6
Book Description
This paper describes a new frequency temperature compensation method for crystal oscillators. The method is applicable to resonators with second order or third order frequency temperature characteristics. Hence, an oscillator with an AT cut, a BT cut crystal unit or a surface acoustic wave resonator (SAWR) can be efficiently compensated. A conventional temperature compensated crystal oscillator (TCXO) uses an expensive variable capacitance diode (varactor) with good linearity as well as many thermistors. Considerable efforts have been devoted to developing a new reactance circuit to replace the varactor. It was found that a series circuit, involving a capacitor and a silicon diode, has the same characteristics as a varactor, and its linearity could be easily adjusted. In the case of an AT cut crystal unit with third order frequency temperature characteristics, compensation over a wide temperature range can be achieved by using two series circuits.
Proceedings of the ... Annual Symposium on Frequency Control
Author:
Publisher:
ISBN:
Category : Oscillators, Crystal
Languages : en
Pages : 436
Book Description
Publisher:
ISBN:
Category : Oscillators, Crystal
Languages : en
Pages : 436
Book Description
Scientific and Technical Aerospace Reports
Temperature Compensated Crystal Oscillator Survey and Test Results
Author: V. Rosati
Publisher:
ISBN:
Category :
Languages : en
Pages : 5
Book Description
To assess the availability and quality of moderate and high precision TCXO, a variety of oscillators was purchased and tested. Tests included frequency-temperature stability and aging. Oscillators in the 1 to 5 ppm stability range were found to conform to specifications, except that aging characteristics were widely variable. Oscillators between 0.5 ppm and 1 ppm did not fare as well. Significant percentages were out of specification. Aging for these oscillators was better, but still disappointing in many cases. No correlation between price and performance was found. Users are cautioned to carefully specify and test candidate oscillators before designing them into systems. (Author).
Publisher:
ISBN:
Category :
Languages : en
Pages : 5
Book Description
To assess the availability and quality of moderate and high precision TCXO, a variety of oscillators was purchased and tested. Tests included frequency-temperature stability and aging. Oscillators in the 1 to 5 ppm stability range were found to conform to specifications, except that aging characteristics were widely variable. Oscillators between 0.5 ppm and 1 ppm did not fare as well. Significant percentages were out of specification. Aging for these oscillators was better, but still disappointing in many cases. No correlation between price and performance was found. Users are cautioned to carefully specify and test candidate oscillators before designing them into systems. (Author).
Proceedings of the Annual Symposium on Frequency Control
Author:
Publisher:
ISBN:
Category : Oscillators, Crystal
Languages : en
Pages : 464
Book Description
Publisher:
ISBN:
Category : Oscillators, Crystal
Languages : en
Pages : 464
Book Description