Method, system and storage medium for calibrating reference voltage by using temperature
阅读说明：本技术 一种利用温度校准基准电压的方法、系统及存储介质 (Method, system and storage medium for calibrating reference voltage by using temperature ) 是由 杨宏 吕尧明 黄海 程飞 吴清源 于 2020-12-09 设计创作，主要内容包括：本发明公开了一种利用温度校准基准电压的方法、系统及存储介质,涉及校准方法的技术领域,其中方法包括获取温度基准T-(REF)、温度基准T-(REF)下的感温电压△Vbe-(TREF)、基准ADC电压值VADC-(TREF)；用模数转换器ADC测量当前温度T下的感温电压△Vbe-T,得到测量ADC电压值VADC-T,根据测量ADC电压值VADC-T、温度基准T-(REF)、基准ADC电压值VADC-(TREF)通过公式：T=VADC-T*T-(REF)/VADC-(TREF),计算得出当前温度T；根据温度基准T-(REF)下的感温电压△Vbe-(TREF)、当前温度T,计算得到当前温度T下的感温电压△Vbe-T,并最终计算出基准电压VREF的值,本发明具有不需要对环境温度做特殊要求、得到的基准电压VREF值相对准确、基准电压校准流程较为简便、成本较低的优点。(The invention discloses a method, a system and a storage medium for calibrating reference voltage by using temperature, relating to the technical field of calibration methods, wherein the method comprises the step of acquiring a temperature reference T REF Temperature reference T REF Temperature sensing voltage delta Vbe TREF Reference ADC voltage value VADC TREF (ii) a Measuring temperature sensing voltage delta Vbe under current temperature T by using analog-to-digital converter ADC T Obtaining a measured ADC voltage value VADC T From measured ADC voltage values VADC T Temperature reference T REF Reference ADC voltage value VADC TREF By the formula: t = VADC T *T REF /VADC TREF Calculating to obtain the current temperature T; according to a temperature reference T REF Temperature sensing voltage delta Vbe TREF Calculating the current temperature T to obtain the temperature sensing voltage delta Vbe under the current temperature T T And finally calculating the value of the reference voltage VREF, the invention has the advantages of no need of making special requirements on the environment temperature, relatively accurate obtained value of the reference voltage VREF and relatively simple calibration process of the reference voltageThe method has the advantages of simplicity and low cost.)
1. A method for calibrating a reference voltage using temperature, comprising:
temperature calibration, obtaining temperature reference TREFTemperature reference TREFTemperature sensing voltage delta VbeTREFReference ADC voltage value VADCTREF；
Obtaining measurement AD with analog-to-digital converter ADCC voltage value VADCTSaid measured ADC voltage value VADCTThe temperature sensing voltage under the current temperature T is measured and converted;
from the measured ADC voltage value VADCTThe temperature reference TREFThe reference ADC voltage value VADCTREFBy the formula: t = VADCT*TREF/VADCTREFCalculating to obtain the current temperature T;
according to said temperature reference TREFTemperature sensing voltage delta VbeTREFThe current temperature T, by the formula: Δ VbeT=△VbeTREF+ K × T, calculating to obtain the temperature sensing voltage delta Vbe under the current temperature TTK is a change value of temperature sensing voltage when unit temperature changes according to a production process;
according to the temperature sensing voltage delta Vbe under the current temperature TTThe measurement ADC voltage value VADCTBy the formula: Δ VbeT=VADCTAnd calculating the value of the reference voltage VREF/2^ 15.
2. The method of calibrating a reference voltage with temperature according to claim 1, wherein the temperature calibration comprises:
in the process of testing the wafer, the temperature reference T is obtained by measurementREF；
Storing the temperature reference T inside a chipREFReference ADC voltage value VADCTREFThe reference ADC voltage value VADCTREFIs to reference said temperature TREFTemperature sensing voltage delta VbeTREFA value obtained by analog-to-digital conversion.
3. The method of calibrating a reference voltage with temperature according to claim 1, wherein said obtaining a measured ADC voltage value VADC with an analog-to-digital converter ADCTThis is done by an analog-to-digital converter inside the chip.
4. The method for calibrating a reference voltage with temperature according to claim 2, wherein said measuring results in a temperatureReference TREFAcquiring a temperature reference T by using a high precision digital temperature sensorREF。
5. The method of calibrating a reference voltage with temperature of claim 1, wherein the temperature reference T isREFAnd the unit of the current temperature T is expressed in degrees Kelvin.
6. The method of calibrating a reference voltage using temperature according to claim 1, wherein the value of the calculated reference voltage VREF is reset as a reference voltage of a chip analog-to-digital converter ADC.
7. A system for calibrating a reference voltage using temperature, comprising:
a temperature calibration module configured to obtain a temperature reference TREFTemperature reference TREFTemperature sensing voltage delta VbeTREFReference ADC voltage value VADCTREF；
A measurement ADC voltage value acquisition module configured to obtain a measurement ADC voltage value VADC with an analog-to-digital converter ADCTSaid measured ADC voltage value VADCTThe temperature sensing voltage under the current temperature T is measured and converted;
a temperature calculation module configured to calculate VADC from the measured ADC voltage valueTThe temperature reference TREFThe reference ADC voltage value VADCTREFBy the formula: t = VADCT*TREF/VADCTREFCalculating to obtain the current temperature T;
a temperature sensing voltage calculation module configured to calculate a temperature sensing voltage according to the temperature reference TREFTemperature sensing voltage delta VbeTREFThe current temperature T, by the formula: Δ VbeT=△VbeTREF+ K × T, calculating to obtain the temperature sensing voltage delta Vbe under the current temperature TTK is the change of temperature sensing voltage when unit temperature changes according to the production processA value;
a reference voltage calculation module configured to calculate a reference voltage Δ Vbe according to a temperature sensing voltage Δ Vbe at the current temperature TTThe measurement ADC voltage value VADCTBy the formula: Δ VbeT=VADCTAnd calculating the value of the reference voltage VREF/2^ 15.
8. A readable storage medium storing a program which, when executed by a processor, causes the processor to perform the steps of the method according to any one of claims 1 to 6.
[ technical field ] A method for producing a semiconductor device
The present invention relates to the field of chip technology, and more particularly, to a method, system and storage medium for calibrating a reference voltage using temperature.
[ background of the invention ]
In many applications, a relatively accurate voltage or current reference is required, for example, the reference of an analog-to-digital converter ADC. In the actual production process of the chip, the reference voltage of the produced chip is always fluctuated due to the fluctuation of the process, so production calibration is needed, the classical mode is that a high-precision voltmeter is utilized to measure the reference voltage, in the actual measurement process, the measurement environment is harsh, the voltage which is stable for a relatively long time is needed, and the stable environment temperature is needed; and sometimes the reference voltage is inside the chip and there are no external pins, so that the voltage cannot be measured by directly measuring the voltage.
[ summary of the invention ]
To overcome the above-mentioned deficiencies in the prior art, the present invention provides a method, system and storage medium for calibrating a reference voltage using temperature.
In order to achieve the above object, the present invention provides a method for calibrating a reference voltage using temperature, comprising:
temperature calibration, obtaining temperature reference TREFTemperature reference TREFTemperature sensing voltage delta VbeTREFReference ADC voltage value VADCTREF(ii) a Obtaining a measured ADC voltage value VADC with an analog-to-digital converter ADCTSaid measured ADC voltage value VADCTThe temperature sensing voltage under the current temperature T is measured and converted; from the measured ADC voltage value VADCTThe temperature reference TREFThe reference ADC voltage value VADCTREFBy the formula: t = VADCT*TREF/VADCTREFCalculating to obtain the current temperature T; according to said temperature reference TREFTemperature sensing voltage delta VbeTREFThe current temperature T, by the formula: Δ VbeT=△VbeTREF+ K × T, calculating to obtain the current temperature TTemperature sensing voltage Δ VbeTK is a change value of temperature sensing voltage when unit temperature changes according to a production process; according to the temperature sensing voltage delta Vbe under the current temperature TTThe measurement ADC voltage value VADCTBy the formula: Δ VbeT=VADCTAnd calculating the value of the reference voltage VREF/2^ 15.
Further, the temperature calibration includes: in the process of testing the wafer, the temperature reference T is obtained by measurementREF(ii) a Storing the temperature reference T inside a chipREFReference ADC voltage value VADCTREFThe reference ADC voltage value VADCTREFIs to reference said temperature TREFTemperature sensing voltage delta VbeTREFA value obtained by analog-to-digital conversion.
Further, obtaining a measured ADC voltage value VADC using the analog-to-digital converter ADCTThis is done by an analog-to-digital converter inside the chip.
Further, the measurement yields a temperature reference TREFAcquiring a temperature reference T by using a high precision digital temperature sensorREF。
Further, the temperature reference TREFAnd the unit of the current temperature T is expressed in degrees Kelvin.
Further, the value of the calculated reference voltage VREF is reset to the reference voltage of the chip analog-to-digital converter ADC.
Has the advantages that:
the method for calibrating the reference voltage by using the temperature has the advantages that the temperature of a chip with a temperature measurement function is calibrated only when the wafer is tested, the reference voltage VREF can be calibrated by calculating according to the temperature calibration result in the practical application process without making special requirements on the environmental temperature, and the reference voltage VREF is calibrated to be within +/-0.2% by measuring the temperature sensing voltage subjected to analog-to-digital conversion at different temperatures.
The features and advantages of the present invention will be described in detail by embodiments in conjunction with the accompanying drawings.
[ description of the drawings ]
FIG. 1 is a block diagram of a high-precision digital temperature sensor for obtaining a temperature reference T during wafer testing according to an embodiment of the present inventionREFSchematic representation of (a).
[ detailed description ] embodiments
In order to make the objects, technical solutions and advantages of the present application more apparent, the present application is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.
Each chip has an internal reference voltage, which is the temperature sensing voltage Δ Vbe. Under specific temperature, the temperature sensing voltage delta Vbe of the chips produced by different processes has small change (within +/-0.1 percent), can be used as a standard voltage measuring point and is connected with an analog-to-digital converter ADC in the chip. The temperature sensing voltage Δ Vbe is basically not changed with the change of the external power supply voltage, is only related to specific temperature, and can be converted into a corresponding ADC voltage signal by an analog-to-digital converter ADC inside the chip and output from a specific pin of the chip.
The reference voltage of the analog-to-digital converter ADC is provided by reference voltage VREF, and in the case that the number of chip pins is large, VREF is led out of a chip and the pin is a Vref + pin, so that the reference voltage VREF can be measured and calibrated by using a high-precision voltmeter correspondingly, but in the actual measurement process, the voltage needs to have enough stable time, and the environment temperature is stable so as to obtain a good measurement result. For some chips adopting a packaging form with fewer pins, VREF is connected with a VCC signal line in the chip, and is not led out of the chip, and a reference voltage VREF cannot be measured in a mode of directly measuring voltage, so that the reference voltage of the analog-to-digital converter ADC is the voltage on VCC, namely the supply voltage of the circuit. Under the condition that the external reference voltage of an analog-to-digital converter ADC fluctuates or VCC changes because the internal part of a chip is connected with VCC, a relatively accurate reference voltage VREF value cannot be obtained, and the problem of low accuracy also exists in the result obtained by performing analog-to-digital conversion by using the reference voltage VREF. The voltage variation range of the reference voltage VREF is +/-3%, and the temperature sensing voltage delta Vbe is utilized to calibrate the reference voltage VREF to be within +/-0.2% by utilizing the method for calibrating the reference voltage by utilizing the temperature provided by the embodiment of the invention.
In an embodiment of the present invention, a method for calibrating a reference voltage by using temperature is provided, which includes the following specific steps: obtaining a temperature reference TREFTemperature reference TREFTemperature sensing voltage delta VbeTREFReference ADC voltage value VADCTREF。
In other embodiments, the temperature reference T is used in temperature calibrationREFCan be performed at the step of wafer testing during chip processing by measuring the temperature reference T during wafer testingREF(ii) a And storing said temperature reference T inside the chip during the chip processingREFAnd a reference ADC voltage value VADCTREFSo that the temperature reference TREFAnd a reference ADC voltage value VADCTREFCan be read at any time, the reference ADC voltage value VADCTREFIs to reference said temperature TREFTemperature sensing voltage delta VbeTREFThe temperature sensing voltage is an analog value which can not be directly output through a chip pin, and the temperature sensing voltage can be correspondingly stored or output through a pin after being converted into a corresponding digital signal through an analog-to-digital conversion ADC. However, the temperature sensing voltage is converted into a digital signal through analog-to-digital conversion, and the steps of sampling and quantizing are required, so that the voltage value of the ADC generated according to the temperature sensing signal is different from the original temperature sensing voltage in value, and the reference voltage VREF is the reference for quantization in the analog-to-digital conversion ADC. Wherein the temperature reference TREFAnd a reference ADC voltage value VADCTREFIt can be stored in registers, RAM, ROM, etc. storage media in the chip.
In other embodiments, FIG. 1 shows the use of high-precision digital temperature sensors to obtain temperature during wafer testingReference TREFAs shown in fig. 1, a high-precision digital temperature sensor is used to obtain a temperature reference T passing through an internal temperature sensor, a 16-bit analog-to-digital converter ADC and a signal processing circuit in sequenceREFSignal, said temperature reference TREFThe unit of the temperature reference T is expressed by Kelvin degrees, which is more favorable for obtaining more accurate temperature reference TREFAnd simplifies the calculation process.
The temperature sensing voltage will change with the temperature change, the analog-to-digital converter inside the chip can sample the current temperature sensing voltage and output the related signal value, in this embodiment, the temperature sensing voltage Δ Vbe under the current temperature T is measured by the analog-to-digital converter ADCTObtaining a measured ADC voltage value VADCTSaid measured ADC voltage value VADCTThe temperature sensing voltage under the current temperature T is measured and converted; the temperature sensing voltage Δ VbeTIs a chip internal signal, is only related to temperature, and is not related to other factors. Because the temperature sensing voltage is only related to the temperature and is unrelated to other factors, the ADC voltage value obtained after the temperature sensing voltage is converted by the ADC is only related to the temperature and is unrelated to other factors, and the ADC voltage value is in linear positive correlation with the temperature. So from said measured ADC voltage value VADCTThe temperature reference TREFThe reference ADC voltage value VADCTREFBy the formula: t = VADCT*TREF/VADCTREFThe current temperature T can be accurately calculated.
In other embodiments, the ADC value VADC is based on the measurementTThe temperature reference TREFThe reference ADC voltage value VADCTREFBy the formula: t = VADCT*TREF/VADCTREFAnd the process of calculating the current temperature T is carried out in the chip, and a temperature signal is output.
In other embodiments, the unit of the current temperature T is expressed by kelvin degrees, which is more beneficial to obtain a more accurate temperature reference TREF。
Temperature sensing voltage delta Vbe at current temperature TTIs the internal signal of the chip, and the chip can not be connected after being packagedThe temperature sensing voltage delta Vbe under the current temperature T is obtained by directly measuring the chipT. Since the temperature sensing voltage is only related to the temperature and the temperature is in a linear positive correlation, the temperature reference T measured during the temperature calibration of the wafer detection can be usedREFTemperature sensing voltage delta VbeTREFAnd a current temperature T, by the formula: Δ VbeT=△VbeTREF+ K × T, calculating to obtain the temperature sensing voltage delta Vbe under the current temperature TTAnd K is a change value of the temperature sensing voltage when the unit temperature changes according to the production process.
In other embodiments, the temperature sensing voltage Δ Vbe at the current temperature T is measured by the analog-to-digital converter ADCTIs performed by an ADC analog-to-digital converter inside the chip.
In this embodiment, since the temperature sensing voltage is converted into the digital signal through the analog-to-digital conversion and the sampling and quantization steps are required, the voltage value of the ADC generated according to the temperature sensing signal is different from the original temperature sensing voltage in value, the reference voltage VREF is the reference for quantization in the analog-to-digital conversion ADC, and the temperature sensing voltage Δ Vbe of the temperature TTAnd the ADC value VADC obtained after the temperature T conversionTThe temperature sensing voltage delta Vbe of the chips produced by different processes has small change (within +/-0.1%) according to the temperature sensing voltage delta Vbe under the current temperature T due to the characteristic of the temperature sensing voltageTThe measurement ADC value VADCTBy the formula: Δ VbeT=VADCTVREF/2^15, the value of the reference voltage VREF can be calculated. Calibrating according to this formula has the advantage of high accuracy, since the formula is distorted, Δ VbeT / VADCTAnd the error on the left side of the formula can be less than +/-0.1% or less, so that the voltage variation range of the reference voltage VREF is calibrated to be +/-0.2% or less from +/-3% originally according to the principle of an equation.
In other embodiments, said reference T is based on said temperatureREFTemperature sensing voltage delta VbeTREFThe current temperature T, by the formula: Δ VbeT=△VbeTREF+ K × T, calculating to obtain the temperature sensing voltage delta Vbe under the current temperature TTTo (2)The process is carried out in the chip, and the temperature sensing voltage delta Vbe under the current temperature T is outputTThe signal is beneficial to the stability of signal transmission in the chip, and the relative error of the final reference voltage VREF is reduced.
In other embodiments, the value of the calculated reference voltage VREF is reset to the reference voltage of the chip analog-to-digital converter ADC.
In other embodiments, there is provided a system for calibrating a reference voltage using temperature, comprising:
a temperature calibration module configured to obtain a temperature reference TREFTemperature reference TREFTemperature sensing voltage delta VbeTREFReference ADC voltage value VADCTREF；
A measurement ADC voltage value acquisition module configured to obtain a measurement ADC voltage value VADC with an analog-to-digital converter ADCTSaid measured ADC voltage value VADCTThe temperature sensing voltage under the current temperature T is measured and converted;
a temperature calculation module configured to calculate VADC from the measured ADC voltage valueTThe temperature reference TREFThe reference ADC voltage value VADCTREFBy the formula: t = VADCT*TREF/VADCTREFCalculating to obtain the current temperature T;
a temperature sensing voltage calculation module configured to calculate a temperature sensing voltage according to the temperature reference TREFTemperature sensing voltage delta VbeTREFThe current temperature T, by the formula: Δ VbeT=△VbeTREF+ K × T, calculating to obtain the temperature sensing voltage delta Vbe under the current temperature TTK is a change value of temperature sensing voltage when unit temperature changes according to a production process;
a reference voltage calculation module configured to calculate a reference voltage Δ Vbe according to a temperature sensing voltage Δ Vbe at the current temperature TTThe measurement ADC voltage value VADCTBy the formula: Δ VbeT=VADCTAnd calculating the value of the reference voltage VREF/2^ 15.
In other embodiments, a readable storage medium is provided, storing a program that, when executed by a processor, causes the processor to perform the steps of one of the above-described methods for calibrating a reference voltage using temperature. The steps of a method for calibrating a reference voltage using temperature herein may be steps in the method for calibrating a reference voltage using temperature of the various embodiments described above.
It will be understood by those skilled in the art that all or part of the processes of the methods of the embodiments described above can be implemented by controlling the related hardware, and the described programs can be stored in a non-volatile computer readable storage medium, and when executed, the programs can include the processes of the embodiments of the methods described above. Any reference to memory, storage, database, or other medium used in the embodiments provided herein may include non-volatile and/or volatile memory, among others. Non-volatile memory can include read-only memory (ROM), Programmable ROM (PROM), Electrically Programmable ROM (EPROM), Electrically Erasable Programmable ROM (EEPROM), or flash memory. Volatile memory can include Random Access Memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in a variety of forms such as Static RAM (SRAM), Dynamic RAM (DRAM), Synchronous DRAM (SDRAM), Double Data Rate SDRAM (DDRSDRAM), Enhanced SDRAM (ESDRAM), Synchronous Link DRAM (SLDRAM), Rambus Direct RAM (RDRAM), direct bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM).
The above embodiments are illustrative of the present invention, and are not intended to limit the present invention, and any simple modifications of the present invention are within the scope of the present invention.
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