CN103036505A - High-accuracy temperature compensation crystal oscillator system and operational method thereof - Google Patents
High-accuracy temperature compensation crystal oscillator system and operational method thereof Download PDFInfo
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Abstract
The invention relates to a high-accuracy temperature compensation crystal oscillator system and an operational method of the high-accuracy temperature compensation crystal oscillator system. The high-accuracy temperature compensation crystal oscillator system comprises a computer, a power supply, an incubator, a frequency meter, a frequency-scaling and data-transporting and displaying unit, a data input and output (DIO) card used for driving the testing controlling board arranged on the computer mainboard in an inserting mode, and a general purpose interface bus (GPIB) card used for driving the incubator, the frequency meter, and the power supply. Software based on event-driving controls the power supply, the incubator and the frequency meter through the DIO card and the GPIB card, reads multiple sets of data of each set temperature point and stores the data inside a computer database. The multiple sets of data are synthesized into a plurality of five-order functions in a set temperature range, and a best curve is calculated by the software. Each coefficient of the best curve is extracted, and is converted into numbers inside the an internal memory of a crystal oscillator chip through an analog to digital (A/D) converter, and therefore the number of capacitors controlled by the memory is changed, and the purpose of high-accuracy temperature compensation of the crystal oscillator is achieved. The high-accuracy temperature compensation crystal oscillator system and the operational method of the high-accuracy temperature compensation crystal oscillator system can be produced in scale and are high in working efficiency.
Description
Technical field
The present invention relates to the crystal oscillator temperature compensation system, particularly a kind of high precision temperature compensation crystal oscillator system and method for operation thereof.
Background technology
The compensation way of temperature compensating crystal oscillator (TCXO) mainly is divided into analog compensation and digital compensation two classes, and the former utilizes the temperature feedback of thermistor network to come the frequency-temperature characteristic curve of analog compensation crystal element; The latter adopts some digital circuits and crystal element, realizes by depositing compensation control data, sensing temperature and digital-to-analogue conversion.Present stage, the voltage signal that digital compensation utilizes hygrosensor to produce generates cubic curve, the size of control variable capacitance.The cubic curve that generates carries out shaping by the adjustment function circuit for generating, to adapt to different crystal.Its frequency temperature stability can only reach ± 1ppm-± 2.5ppm in-40 ℃ of-85 ℃ of wide temperature ranges, but along with the development of the market demand, this precision can not satisfy the demand in high-end technology field.At present, the compensation precision of raising temperature compensation system has become a urgent problem.Therefore, be badly in need of a kind of high precision temperature compensation of exploitation system and overcome above defective.
Summary of the invention
The present invention is intended to solve the problems referred to above that existing crystal oscillator temperature compensation system exists, and a kind of high precision temperature compensation crystal oscillator system and method for operation thereof are provided.
In order to achieve the above object, the technical solution used in the present invention is:
A kind of high precision temperature compensation crystal oscillator system comprises computer, power supply, incubator, frequency meter, frequency marking, D/A conversion unit, data transmission unit and data display unit, and described incubator inside is placed with test control panel; Described computer motherboard inserts for the DIO card that drives test control panel with for the GPIB card that drives incubator, frequency meter, power supply; Described frequency marking links to each other with the interface of frequency meter; Described D/A conversion unit is electrically connected with the crystal oscillator inside chip by data transmission unit, the data of control crystal oscillator inside chip write and read, described data display unit shows data by frequency meter, power supply, incubator, and it is stored in the Computer Database.
As preferred version, described frequency marking is high accuracy atom frequency marker.The short-term stability of high accuracy atom frequency marker can reach the 1E-14 magnitude, in order to the frequency reference source as crystal oscillator, has improved the frequency temperature stability of temperature compensating crystal oscillator and the accuracy of frequency accuracy.
As preferred version, native system also comprises for the interconnected interfacing expansion module of external equipment.Compatible powerful, carry the multiple popular interface such as serial ports, print.er port, USB, be convenient to the analysis of various device joint test.
In the technical program, pass through GPIB card control power supply, incubator and frequency meter based on event driven software; Choose the address of each crystal oscillator on the test control panel by the DIO card control; Read by frequency meter setting each temperature spot many class frequencys value and the data that read are stored in the system database.In the temperature range of setting, multi-group data is fitted to a plurality of five rank functions based on event driven software, to organize five rank curves by the rudimentary algorithm of software infinitely approaches more, draw a best curve, extract every coefficient of this best curve, convert numerical value in the crystal oscillator chip internal register to by A/D converter, thereby change the electric capacity quantity of register control, reach the crystal oscillator high accuracy (purpose of temperature-compensating of frequency temperature stability in the wide temperature range ± 0.28ppm) with this.
The method of operation of above-mentioned high precision temperature compensation crystal oscillator system, carry out in the steps below:
A. initial value setting: needed parameter in the design temperature compensation process comprises: nominal frequency, frequency temperature stability, frequency accuracy, temperature range, Temperature of Warm Case precision, each temperature spot soak time, supply voltage, five function coefficients;
B. choosing of crystal oscillator address bit: test by the crystal oscillator that the DIO card is chosen on the test control panel;
C. the calculating of the crystal linearity: choose two temperature spots in the temperature range, soaked 10 minutes at each temperature spot, reading frequency is according to the numerical computations crystal linearity that reads;
D. the frequency temperature stability of crystal oscillator is calculated: the nominal frequency of setting crystal oscillator is F1, frequency under 25 ℃ ± 2 ℃ is F2, in-40 ℃ of-85 ℃ of temperature ranges, choose a plurality of temperature spots and carry out reading out data, data streams read is set as F3, and frequency temperature stability computing formula is as follows: (F3-F2)/F1;
E. temperature scanning, data extraction procedure: the some temperature spots in the design temperature scope, carrying out data extracts, when the initial value setting up procedure, system is provided with five function coefficients, and there is a step value in each function coefficient, and 11 groups of data can occur in the process that data are extracted: first group of data depends on initial set value; Second group of data is that all the other four function coefficients of setting are constant, and first function coefficient increases a step value, reading out data; The 3rd group of data are that all the other four function coefficients of setting are constant, and first function coefficient reduces a step value, reading out data; By parity of reasoning, obtains all the other and respectively organize data;
F. data write: 11 groups of data among the step e are fitted to 11 group of five rank function curve in whole temperature range, use least square method infinitely to approach out a best curve based on event driven software, extract each time coefficient of this curve, be voltage signal with each time coefficients conversion, change voltage signal into digital quantity by A/D converter, digital quantity is write in the register, digital quantity is addressing in chip register, obtain the bucking voltage amount corresponding with it, form bucking voltage by the D/A conversion again;
G. the accuracy of adjusting frequency: computer sends instruction, and incubator runs to 25 ℃ ± 0.3 ℃, soaks 10 minutes;
H. temperature test: the nominal frequency of setting crystal oscillator is F1, a plurality of temperature spots is set, reading out data F3 in-40 ℃ of-85 ℃ of wide temperature ranges; 25 ℃ that choose wherein are reference temperature, reading out data F2; Frequency temperature stability computing formula is as follows: (F3-F2)/F1, extract | the maximum of (F3-F2)/F1| and 0.28ppm comparison, be judged to be defectively greater than 0.28ppm, it is qualified to be judged to be less than 0.28ppm.
Compared with prior art, the present invention has improved the temperature-compensating precision, and it is reached ± 0.28ppm in wide temperature (40 ℃-85 ℃) scope; Test control panel exist to be reserved address bit, can carry out on this basis the address bit expansion, can large-scale production, greatly improved operating efficiency.
Description of drawings
Fig. 1 is embodiment of the invention system configuration schematic diagram.
Fig. 2 is embodiment of the invention working-flow figure.
Fig. 3 is effect temperature compensation figure of the present invention.
Among the figure: control unit 1, transfer of data and display unit 2, test control panel 3, crystal oscillator 4, power supply 101, frequency marking 102, frequency meter 103, computer 104, incubator 105, D/A conversion unit 201, data transmission unit 202, data display unit 203.
Embodiment
Description by following examples and by reference to the accompanying drawings, it is more clear that the present invention will become, and these accompanying drawings are used for explaining embodiments of the invention.
Referring to Fig. 1, the hardware configuration of this high precision temperature compensation crystal oscillator system is comprised of control unit 1, transfer of data and display unit 2, test control panel 3, crystal oscillator 4, control unit 1 is comprised of power supply 101, frequency marking 102, frequency meter 103, computer 104, incubator 105, and transfer of data and display unit 2 are comprised of D/A conversion unit 201, data transmission unit 202, data display unit 203.
The incubator 105 inner test control panels 3 of placing arrange crystal oscillator 4 on the test control panel 3, computer 104 mainboards insert DIO card and GPIB card.The DIO card is used for driving test control panel 3, and the GPIB card is used for driving incubator 105, frequency meter 103 and power supply 101, and frequency marking 102 links to each other with the interface of frequency meter 103, and frequency marking 102 adopts high accuracy atom frequency marker.
Pass through GPIB card control power supply 205, incubator 202 and frequency meter 203 in the control unit 101 based on event driven software; Choose the address of each crystal oscillator 4 on the test control panel 3 by the DIO card control in the control unit 1; Read by frequency meter 103 setting each temperature spot many class frequencys value and the data that read are stored in the system database.D/A conversion unit 201 is electrically connected with crystal oscillator 4 inside chips by data transmission unit 202, the conversion of solution analog signal and digital signal with communicate by letter; Data transmission unit 202 adopts total line traffic control transmission, and the data of control crystal oscillator 4 inside chips write and read; Data display unit 203 shows data, and it is stored in the Computer Database by frequency meter 103, power supply 101, incubator 105.
Need to prove that the quantity of test control panel 3 depends on the size in incubator 105 spaces among the present invention, can increase according to actual needs.Owing to adopt multiple shield technology, in the batch production crystal oscillator, guaranteed the stability of crystal oscillator.In order to adapt to the product of Multiple Type, can be according to the different test fixture of model customization of product.
Referring to Fig. 2, the workflow of this high precision temperature compensation crystal oscillator system is as follows:
A. initial value setting.Needed parameter in the design temperature compensation process.The for example setting of nominal frequency, frequency temperature stability, frequency accuracy, temperature range, Temperature of Warm Case precision, each temperature spot soak time, supply voltage, five function coefficients.
B. the crystal oscillator address bit chooses.The crystal oscillator 4 that control unit 1 is chosen on the test control panel 3 by the driving logic chip is tested.
C. the calculating of the crystal linearity.Choose two temperature spots in the temperature range, soaked 10 minutes at each temperature spot, reading frequency is according to the numerical computations crystal linearity that reads.
D. the frequency-temperature characteristic of crystal oscillator.The nominal frequency of setting crystal oscillator 4 is F1, and the frequency under normal temperature (25 ℃ ± 2 ℃) is F2, suppose in-40 ℃ of-85 ℃ of temperature ranges, to choose a plurality of temperature spots and carry out reading out data, as per 5 ℃ a bit, data streams read is set as F3.Frequency temperature stability computing formula is as follows: (F3-F2)/F1.
E. temperature scanning, data extraction procedure.Some temperature spots in the design temperature scope carry out data and extract.When the initial value setting up procedure, system is provided with five function coefficients, and there is a step value in each function coefficient, and 11 groups of data can occur in the process that data are extracted: first group of data depends on initial set value; Second group of data is that all the other four function coefficients of setting are constant, and first function coefficient increases a step value, reading out data; The 3rd group of data are that all the other four function coefficients of setting are constant, and first function coefficient reduces a step value, reading out data; By parity of reasoning, obtains all the other and respectively organize data.
F. data write.11 groups of data among the step e are fitted to 11 group of five rank function curve in whole temperature range, use least square method infinitely to approach out a best curve based on event driven software, extract each time coefficient of this curve, be voltage signal with each time coefficients conversion, change voltage signal into digital quantity by A/D converter, digital quantity is write in the register.Digital quantity is addressing in chip register, obtains the bucking voltage amount corresponding with it, forms bucking voltage by the D/A conversion again.
G. the accuracy of adjusting frequency.Control unit 1 sends instruction, and incubator 105 runs to 25 ℃ ± 0.3 ℃, soaks 10 minutes.
H. temperature test.Data writing is calculated value, and need to carry out 100% test in-40 ℃ of-85 ℃ of temperature ranges to crystal oscillator 4: the nominal frequency of setting crystal oscillator 4 is F1, a plurality of temperature spots is set, reading out data F3 in-40 ℃ of-85 ℃ of wide temperature ranges; 25 ℃ that choose wherein are reference temperature, reading out data F2; Frequency temperature stability computing formula is as follows: (F3-F2)/F1, extract | the maximum of (F3-F2)/F1| and 0.28ppm comparison, be judged to be defectively greater than 0.28ppm, it is qualified to be judged to be less than 0.28ppm.
Referring to Fig. 3, Fig. 3 has provided the effect temperature compensation figure that present embodiment provides.Show among the figure that temperature compensation system reaches ± 0.15ppm the compensation precision of the frequency temperature stability of crystal oscillator in-40 ℃ of-85 ℃ of scopes, satisfies the index of frequency temperature stability ± 0.28ppm in wide temperature range far away.
In sum, utilization of the present invention becomes five order frequencies-temperature curve based on event driven computer testing software model with the data fitting that gathers, and has greatly improved the temperature-compensating precision; Use the least square method close approximation to calculate every coefficient of five rank functions, obtain theoretical optimal value; Utilize the calculated value of temperature test function checking temperature compensating crystal oscillator.
Claims (4)
1. a high precision temperature compensation crystal oscillator system comprises computer, power supply, incubator, frequency meter, frequency marking, D/A conversion unit, data transmission unit and data display unit, it is characterized in that, described incubator inside is placed with test control panel; Described computer motherboard inserts for the DIO card that drives test control panel with for the GPIB card that drives incubator, frequency meter, power supply; Described frequency marking links to each other with the interface of frequency meter; Described D/A conversion unit is electrically connected with the crystal oscillator inside chip by data transmission unit, the data of control crystal oscillator inside chip write and read, described data display unit shows data by frequency meter, power supply, incubator, and it is stored in the Computer Database.
2. the system of high precision temperature compensation crystal oscillator as claimed in claim 1 is characterized in that, described frequency marking is high accuracy atom frequency marker.
3. high precision temperature compensation crystal oscillator as claimed in claim 1 system is characterized in that, also comprises for the interconnected interfacing expansion module of external equipment.
4. method of operation of high precision temperature compensation crystal oscillator system as claimed in claim 1, carry out in the steps below:
A. initial value setting: needed parameter in the design temperature compensation process comprises: nominal frequency, frequency temperature stability, frequency accuracy, temperature range, Temperature of Warm Case precision, each temperature spot soak time, supply voltage, five function coefficients;
B. choosing of crystal oscillator address bit: test by the crystal oscillator that the DIO card is chosen on the test control panel;
C. the calculating of the crystal linearity: choose two temperature spots in the temperature range, soaked 10 minutes at each temperature spot, reading frequency is according to the numerical computations crystal linearity that reads;
D. the frequency temperature stability of crystal oscillator is calculated: the nominal frequency of setting crystal oscillator is F1, frequency under 25 ℃ ± 2 ℃ is F2, in-40 ℃ of-85 ℃ of temperature ranges, choose a plurality of temperature spots and carry out reading out data, data streams read is set as F3, and frequency temperature stability computing formula is as follows: (F3-F2)/F1;
E. temperature scanning, data extraction procedure: the some temperature spots in the design temperature scope, carrying out data extracts, when the initial value setting up procedure, system is provided with five function coefficients, and there is a step value in each function coefficient, and 11 groups of data can occur in the process that data are extracted: first group of data depends on initial set value; Second group of data is that all the other four function coefficients of setting are constant, and first function coefficient increases a step value, reading out data; The 3rd group of data are that all the other four function coefficients of setting are constant, and first function coefficient reduces a step value, reading out data; By parity of reasoning, obtains all the other and respectively organize data;
F. data write: 11 groups of data among the step e are fitted to 11 group of five rank function curve in whole temperature range, use least square method infinitely to approach out a best curve based on event driven software, extract each time coefficient of this curve, be voltage signal with each time coefficients conversion, change voltage signal into digital quantity by A/D converter, digital quantity is write in the register, digital quantity is addressing in chip register, obtain the bucking voltage amount corresponding with it, form bucking voltage by the D/A conversion again;
G. the accuracy of adjusting frequency: computer sends instruction, and incubator runs to 25 ℃ ± 0.3 ℃, soaks 10 minutes;
H. temperature test: the nominal frequency of setting crystal oscillator is F1, a plurality of temperature spots is set, reading out data F3 in-40 ℃ of-85 ℃ of wide temperature ranges; 25 ℃ that choose wherein are reference temperature, reading out data F2; Frequency temperature stability computing formula is as follows: (F3-F2)/F1, extract | the maximum of (F3-F2)/F1| and 0.28ppm comparison, be judged to be defectively greater than 0.28ppm, it is qualified to be judged to be less than 0.28ppm.
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Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103293505A (en) * | 2013-06-06 | 2013-09-11 | 中国电子科技集团公司第四十一研究所 | Electronic calibration component and temperature compensation method for broadening operating temperature range thereof |
| CN104143961A (en) * | 2014-07-25 | 2014-11-12 | 广东大普通信技术有限公司 | Frequency calibration method, device and system for oven controlled crystal oscillator |
| CN104833446A (en) * | 2015-05-08 | 2015-08-12 | 福州大学 | CMOS temperature sensing chip test system |
| CN105467242A (en) * | 2015-12-09 | 2016-04-06 | 张宇恒 | A production testing system of digital temperature compensated crystal oscillators and a debugging method thereof |
| CN106301224A (en) * | 2016-08-15 | 2017-01-04 | 成都菁汇科技有限公司 | A kind of crystal oscillator automatic temperature compensation system |
| CN106505996A (en) * | 2016-10-12 | 2017-03-15 | 河海大学 | A kind of RTC chip high accuracy frequency bias compensation method of combination variable capacitance |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1411288A (en) * | 2001-10-10 | 2003-04-16 | 德金通电讯（深圳）有限公司 | Intercom crystal oscillator digital temperature compensating method and its system |
| CN1829076A (en) * | 2006-03-28 | 2006-09-06 | 青岛硅盛微电子有限公司 | High precision temperature compensation crystal oscillator |
| CN201213249Y (en) * | 2008-06-26 | 2009-03-25 | 廊坊中电大成电子有限公司 | Highly precise, highly efficient temperature compensating test system |
| CN201298822Y (en) * | 2008-11-04 | 2009-08-26 | 湖北致源电子股份有限公司 | High-frequency wide-temperature high-accuracy temperature compensation crystal oscillator |
| CN101609126A (en) * | 2009-07-16 | 2009-12-23 | 东莞市大普通信技术有限公司 | The Auto-Test System of temperature compensating crystal oscillator |
| CN101604970B (en) * | 2009-07-02 | 2012-05-02 | 广州市天马电讯科技有限公司 | Self-fitting digital temperature compensation crystal oscillistor and system and realization method thereof |
| CN202231673U (en) * | 2011-10-18 | 2012-05-23 | 北京科瑞思特电子有限公司 | High-precision temperature compensated crystal oscillator |
| CN202949392U (en) * | 2012-12-19 | 2013-05-22 | 同方国芯电子股份有限公司 | High-precision temperature compensated crystal oscillator system |
-
2012
- 2012-12-19 CN CN2012105539387A patent/CN103036505A/en active Pending
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1411288A (en) * | 2001-10-10 | 2003-04-16 | 德金通电讯（深圳）有限公司 | Intercom crystal oscillator digital temperature compensating method and its system |
| CN1829076A (en) * | 2006-03-28 | 2006-09-06 | 青岛硅盛微电子有限公司 | High precision temperature compensation crystal oscillator |
| CN201213249Y (en) * | 2008-06-26 | 2009-03-25 | 廊坊中电大成电子有限公司 | Highly precise, highly efficient temperature compensating test system |
| CN201298822Y (en) * | 2008-11-04 | 2009-08-26 | 湖北致源电子股份有限公司 | High-frequency wide-temperature high-accuracy temperature compensation crystal oscillator |
| CN101604970B (en) * | 2009-07-02 | 2012-05-02 | 广州市天马电讯科技有限公司 | Self-fitting digital temperature compensation crystal oscillistor and system and realization method thereof |
| CN101609126A (en) * | 2009-07-16 | 2009-12-23 | 东莞市大普通信技术有限公司 | The Auto-Test System of temperature compensating crystal oscillator |
| CN202231673U (en) * | 2011-10-18 | 2012-05-23 | 北京科瑞思特电子有限公司 | High-precision temperature compensated crystal oscillator |
| CN202949392U (en) * | 2012-12-19 | 2013-05-22 | 同方国芯电子股份有限公司 | High-precision temperature compensated crystal oscillator system |
Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103293505A (en) * | 2013-06-06 | 2013-09-11 | 中国电子科技集团公司第四十一研究所 | Electronic calibration component and temperature compensation method for broadening operating temperature range thereof |
| CN103293505B (en) * | 2013-06-06 | 2015-11-25 | 中国电子科技集团公司第四十一研究所 | A kind of temperature compensation widening operating temperature range |
| CN104143961A (en) * | 2014-07-25 | 2014-11-12 | 广东大普通信技术有限公司 | Frequency calibration method, device and system for oven controlled crystal oscillator |
| CN104143961B (en) * | 2014-07-25 | 2018-01-19 | 广东大普通信技术有限公司 | A kind of constant-temperature crystal oscillator transmitting frequency calibration method, apparatus and system |
| CN104833446A (en) * | 2015-05-08 | 2015-08-12 | 福州大学 | CMOS temperature sensing chip test system |
| CN104833446B (en) * | 2015-05-08 | 2017-07-04 | 福州大学 | A kind of CMOS TEMPs chip test system |
| CN105467242A (en) * | 2015-12-09 | 2016-04-06 | 张宇恒 | A production testing system of digital temperature compensated crystal oscillators and a debugging method thereof |
| CN106301224A (en) * | 2016-08-15 | 2017-01-04 | 成都菁汇科技有限公司 | A kind of crystal oscillator automatic temperature compensation system |
| CN106301224B (en) * | 2016-08-15 | 2018-10-16 | 成都菁汇科技有限公司 | A kind of crystal oscillator automatic temperature compensation system |
| CN106505996A (en) * | 2016-10-12 | 2017-03-15 | 河海大学 | A kind of RTC chip high accuracy frequency bias compensation method of combination variable capacitance |
| CN106505996B (en) * | 2016-10-12 | 2019-02-12 | 河海大学 | A kind of RTC chip high-precision frequency bias compensation method of combination variable capacitance |
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Application publication date: 20130410 |