90 results about "Drift coefficient" patented technology

The invention discloses a multi-range integrated pressure sensor chip which comprises a silicon substrate, wherein two or more pressure sensors with different ranges are arranged on the silicon substrate; each pressure sensor consists of a corrosion hole, a membrane and strain resistors; the four symmetric strain resistors are respectively arranged on the upper surface of each membrane and connected with one another through conductors to form a Wheatstone bridge; the membranes are connected with the silicon substrate to form a cavity; and the corrosion holes are formed on the supporting edges of the membranes. The multi-range integrated pressure sensor chip has the characteristics of being small in size, wide in range, high in low-voltage sensitivity, small in temperature drift coefficient and compatible in manufacturing process and integrated circuit process, can be used for multipath pressure measurement in automobiles, pressure measurement of environment control and pressure measurement in the fields of aviation systems, petrochemical industries and the like, and is suitable for popularization and application.

The invention discloses a sub-threshold full CMOS reference voltage source. A start-up circuit helps a reference voltage source from getting rid of a degeneration bias point to enter the normal working state. A sub-threshold operation amplifier is ensured to run at low power consumption while being larger in gain at the same time. In this way, the voltage rejection ratio of the power supply is increased. An Nano-ampere reference current generating circuit generates a Nano-ampere-level reference current and suppresses the generation of the noise of the power supply so as to provide a current bias for a reference voltage generating circuit. The reference voltage generating circuit is composed of two MOS tube gate voltage differences of different standard voltages, wherein a reference voltage independent of the temperature is obtained through the coadjustment process. According to the invention, no passive resistor, diode or triode is adopted, and the sub-threshold full CMOS reference voltage source is compatible with the standard CMOS process. Therefore, the layout area is greatly reduced, and the production cost is lowered. The sub-threshold full CMOS reference voltage source is small in power consumption, high in power supply rejection ratio, low in temperature drift coefficient and low in power supply voltage regulation rate.

The invention discloses an optimal position calibration method of a static drifting zero and primary acceleration related term error model of a flexible gyroscope, which acquires an optimal test position by adopting a D-optimal test design method. In the invention, the output of the flexible gyroscope is effectively improved by carrying out measured value compensation on acquired optimal space quadrature-12 position drifting coefficients and an acquired flexible gyro static error compensation model G0 under the optimal space quadrature-12 position; the drifting coefficients are acquired by respectively adopting a traditional 8-position method, a full-space quadrature-24 position method and an optimal space quadrature-12 position method in the flexible gyro test process in an inertial navigation center; and the residual square sum of gyro testing values can shows that a solved result of the drifting coefficients after being compensated by utilizing the optimal space quadrature-12 position test design method of the flexible gyroscope is improved by 4 to 5 times compared with the traditional 8-position method, the precision is improved and the test time is shortened by half compared with the full-space quadrate-24 position test method.

The invention provides a temperature sensor applied to a metering ammeter. The temperature sensor comprises an analog circuit portion, a digital circuit portion and a user ARM portion. The analog circuit portion comprises a positive temperature coefficient current generator in direct-proportion current bias with an absolute temperature, a bias current mirror array, a low-temperature drift coefficient reference current source, a temperature-sensitive transistor and an analog-to-digital conversion integrator. The digital circuit portion comprises a switch control logic, a digital code output, a digital counter and a shift register. The analog-to-digital conversion integrator has a sampling capacitor and an integrating capacitor, of which the capacitance is same; and bias current of the temperature-sensitive transistor is biased by six unit current mirrors in turns in a proportion of 5:1. According to a temperature trimming method for the temperature sensor, the number of the bias current mirrors is 6, wherein 5 paths of currents are used for coarse tuning, and the other one path of current is used for fine tuning; when the output bias of the counter is relatively large, the 5 paths of coarse-tuning currents are used; and when the output of the counter is between the two paths of unit currents, fine tuning is used.

The invention discloses a low-voltage low-power band gap reference voltage source implemented by a MOS (Metal Oxide Semiconductor) device, which is implemented through the CMOS (Complementary Metal Oxide Semiconductor) technology, and comprises a circuit generating a current positively proportional to the temperature, a circuit generating a current inversely proportional to the temperature, a temperature secondary compensation circuit and a starting circuit; wherein the circuit generating the current positively proportional to the temperature obtains a voltage positively proportional to the temperature via a resistor, and simultaneously, the circuit generating the current inversely proportional to the temperature obtains a voltage inversely proportional to the temperature via the resistor, and the two voltages are added up to obtain a reference voltage unrelated to the temperature; additionally, the temperature secondary compensation circuit is used for compensating a high-order temperature coefficient of the reference voltage source so as to obtain a lower temperature-drift coefficient; the low-voltage low-power band gap reference voltage source provided by the invention has the advantages of low static power consumption, low temperature-drift coefficient, and capability of working in low-voltage environment and the like, and further improves the performance of the circuit.

The invention discloses and optimal twenty-four position calibration method for flexible gyroscope static drift error model. The flexible gyroscope is installed on the triaxial position rate table. The flexible gyroscope is connected with a data acquisition device. The data acquisition device is connected with a computer. The invention is designed by using disperse D-optimal design construction method. Twenty-four spatial position orientations are selected form the whole testing space to be as the gyro coordinate system orientation and to be tested. The optimal drift coefficient in the flexible gyroscope static drift error model means the flexible gyroscope static drift error model drift coefficient obtained by the flexible gyroscope optical twenty-four position testing data, which is most close to the true value of the drift coefficient. Namely, after the flexible gyroscope static drift error is compensated by the optimal drift coefficient obtained through calibration, the survey precision of the flexible gyroscope can be further improved.

The invention discloses an optimum eight-place standardization method of a flexible gyroscope, the flexible gyroscope is arranged on a three-shaft place rate rotary table, wherein, the flexible gyroscope is connected with data collecting equipment which is communicated with a computer. The invention discloses a specific position in the optimum eight-place standardization, and the output of the flexible gyroscope is effectively improved in the way that the invention compensates a measurement value of a compensation model G0 of obtained optimum eight-place drifting coefficients and vibrating reed gyro quiet errors. In a testing process of the vibrating reed gyro in an inertial navigation testing center, a traditional eight-place method and the optimum eight-place method are respectively adopted to obtain the drifting coefficients which respectively and objectively output compensated evaluation results of another three-place top in space. By residual sum of square of a top measurement value, compared with the traditional eight-place method, the results of compensated drifting coefficients solved by the optimum eight-place experiment design method of the flexible gyroscope are increased by 4 to 8 times.

The invention discloses a method for improving precision of a laser range finder. The method comprises the following steps: S10: compensating and cancelling the influence, caused by an LD (Laser Diode), on the environment; S11, compensating and cancelling the influence, caused by environment, on an APD (Avalanche Photon Diode), wherein step S11 comprises the following steps: firstly, obtaining a temperature shift coefficient of the APD, using an NTC (Negative Temperature Coefficient) to sample the environment temperature of a photosensitive element to obtain a temperature value; then, calculating the increased volt quantity of a bias voltage of the APD when the temperature raises one DEG C according to the temperature compensation coefficient of the APD; and finally, controlling a booster circuit, so that an ADC (Analog to Digital Converter) samples the voltage to a PWM (Pulse-Width Modulation)-control booster circuit to obtain the corresponding bias voltage, and compensating the bias voltage of the APD by adopting an APD temperature compensation rate. The temperature shift coefficient of the APD is measured, the amplifying logarithm to the APD is compensated, and the amplifying factor of the APD is consistent at any temperature, so that the consistence of the product is ensured during large-scale production.

The invention provides a frequency tracking detection type radio altimeter simulator which comprises a frequency detection unit, a height simulation unit, a frequency conversion unit, a fading simulation unit and an embedded computer. According to the frequency tracking detection type radio altimeter simulator provided by the invention, the height value simulation is accurate to meter; the range covers the whole measurement range of an altimeter; a frequency synthesis mode is used to carry out signal simulation; compared with the existing technology, the measurement accuracy is greatly improved, and the frequency tracking detection type radio altimeter simulator is convenient and quick; VCO whose low temperature drift frequency is 1GHz is used as the time reference of three local oscillators; and a measurement circuit has a small temperature drift coefficient.

A memory includes a programmable resistance array with high ratio of dynamic range to drift coefficient phase change memory devices.

The invention relates to an adaptive compensation method for inhibiting bias point drift of a Mach-Zehnder modulator. The method comprises the following steps of: adopting a thermal resistor to detect the environment temperature at a waveguide part of the Mach-Zehnder modulator; inputting a resistance value of the thermal resistor into a bias point control circuit of the Mach-Zehnder modulator, wherein the output quantity of the bias point control circuit of the Mach-Zehnder modulator is the bias voltage of the Mach-Zehnder modulator; establishing an expression about the environment temperature at the waveguide part of the Mach-Zehnder modulator of the bias voltage; and realizing the adaptive compensation that a bias point of the Mach-Zehnder modulator drifts along with the changes of theenvironment temperature by using the expression. The adaptive compensation method obtains a drift coefficient about environment temperature variable of the bias point of the Mach-Zehnder modulator bymeasuring the drift quantity of the bias point of the Mach-Zehnder modulator along with the changes of the environment temperature, and inputs the drift coefficient into the bias point control circuit of the Mach-Zehnder modulator to ensure that the bias voltage output by the control circuit changes along with the changes of the environment temperature.

The invention discloses a band-gap reference voltage source with the curvature compensation function. The band-gap reference voltage source with the curvature compensation function comprises a one-order temperature compensation circuit, a curvature compensation circuit and a band-gap reference voltage generating circuit, wherein the one-order temperature compensation circuit is used for generating same-order current irrelevant to temperature, the curvature compensation circuit is used for generating current with a high-order temperature characteristic and superimposing the current with the high-order temperature characteristic and the same-order current irrelevant to temperature so that the current irrelevant to temperature can be generated, the band-gap reference voltage generating circuit is used for transmitting the current irrelevant to temperature to the output end and converting the current into voltage, the one-order temperature compensation circuit is connected with the curvature compensation circuit, and the curvature compensation circuit is connected with the band-gap reference voltage generating circuit, and the one-order temperature compensation circuit, the curvature compensation circuit and the band-gap reference voltage generating circuit jointly form the band-gap reference voltage source. Through the band-gap reference voltage source, the accuracy of compensating current can be effectively improved, the temperature drift coefficient of output reference voltage is reduced, and therefore the temperature stability of the output reference voltage can be improved.

The invention discloses an all-CMOS (Complementary Metal Oxide Semiconductor) reference voltage source with a high power supply rejection ratio, which comprises a reference voltage source. The reference voltage source comprises a starting circuit, a current source circuit and a temperature compensating circuit, wherein an output end of the starting circuit is connected with an input end of the current source circuit; an output end of the current source circuit is connected with an input end of the temperature compensating circuit; an output end of the temperature compensating circuit forms an output end of the whole reference voltage source. The working characteristic of an MOS transistor working in a sub-threshold region is utilized by the all-CMOS reference voltage source, a nanoampere-magnitude reference current is generated; power supply noise is rejected by adopting a cascode current mirror. In addition, the all-CMOS reference voltage source not only has the advantages that the chip area is small and the power consumption is low and is only nanowatt-magnitude, but also has the advantages that the all-CMOS reference voltage source has the high power supply rejection ratio, the temperature drift coefficient is low, and the line-voltage regulation is low; moreover, a resistor, a diode and a triode are not used; the all-CMOS reference voltage source is compatible with a standard CMOS process; the layout area is effectively reduced; the production cost is decreased.

Methods for making thin film filters having a negative temperature drift coefficient are the subject of the present invention. Such filters can achieve better optical control within an operational temperature range from -5 to 70 degrees centigrade. A first embodiment of the present invention includes the steps of: 1. providing a substrate wafer which has a coefficient of thermal expansion (CTE) greater than that of a selected film stack material; 2. polishing the substrate wafer; 3. depositing thin film layers made of the film stack material on the substrate wafer at a temperature substantially higher than room temperature; 4. cooling the substrate-film stack laminate to room temperature, thus forming a convex-shaped laminate; 5. cutting the cooled laminate into pieces. A second embodiment includes the steps of: 1. providing a laminate compose of a glass substrate and a film stack; 2. using at least one ion beam source to bombard the film stack of the laminate with high energy ions; 3. cutting the bombarded laminate into pieces.

The invention discloses an O-shaped rubber seal ring service life prediction method based on multivariate sample differences. The O-shaped rubber seal ring service life prediction method comprises the specific steps that a multivariate nonlinear Wiener process degradation model of an O-shaped rubber seal ring is established; parameter variable function models are established, including data statistics and analysis and the function relation of parameters and stresses; a reliability service life calculation model is established; unknown parameters are calculated; the storage life of the O-shaped rubber seal ring is predicted under normal temperature and stress. The differences of sample individuals of O-shaped rubber seal rings are considered, mean values and standard deviations of drift coefficients, diffusion coefficients and Copulas parameters in the Wiener process are processed into variables, and the variables and an acceleration stress form a function relation, so that final prediction results are more in line with the actual engineering situation and are more accurate.

The invention discloses a reference current source circuit compensating resistor temperature drift coefficient. The reference current source circuit comprises a band-gap reference voltage source, a voltage-current converting module, a temperature compensating current generating module and a current summing module. The output of the band-gap reference voltage source is connected with an input end of the voltage-current converting module. An output end of the temperature compensating current generating module is connected with the current summing module. An output end of the voltage-current converting module is connected with the current summing module. An output end of the current summing module outputs zero temperature drift current. The reference current source circuit is simple in structure, high in stability and reliability, capable of obtaining accurate zero temperature drift reference current, and easy to popularize and use.

The invention provides a low-temperature drift band gap reference voltage circuit and method, and a chip of the circuit. The circuit comprises a self-biasing module, a band gap reference core module and a voltage generation module. The method comprises the following steps of generating a primary reference voltage; generating a reference voltage before compensation through base current correction and the primary reference voltage; and generating a low-temperature drift band gap reference voltage. The low-temperature drift band gap reference voltage circuit and method is applied to a power management chip. The method has the advantages that the band gap reference voltage source circuit with ultrahigh precision and an ultralow-temperature drift coefficient is realized, and the high-stabilityreference voltage can be provided for circuit applications with relatively high reference voltage requirements.

The invention discloses a method for predicting remaining life of a LED driving power of railway vehicles, belonging to the technical field of reliability engineering. The method comprises the following steps of: 1, establishing a degradation model of the LED driving power of railway vehicles based on a Wiener process; 2, constructing a relation between a drift coefficient Theta and a temperature and humidity stress in the degradation model through a Hallberg-peck accelerated model; 3, using non-informative prior distribution, updating parameters in the degradation model through a Bayes method, and thereby obtaining posteriori distribution thereof; 4, using temperature and humidity as accelerated stress, acquiring performance degradation data of the LED driving power of railway vehicles in real time, putting the data in a Bayes algorithm, and extrapolating the reliability and the remaining life of the LED driving power of railway vehicles under normal stress condition. The method provided by the invention has the advantages of being capable of improving precision of prediction of the remaining life of the LED driving power of railway vehicles, and reducing uncertainty of prediction.

The invention discloses a high-precision current mode reference voltage source. The high-precision current mode reference voltage source comprises a starting circuit, a CTAT reference current source circuit, a PTAT reference current source circuit and a temperature compensation circuit. A passive resistor, a diode or a triode is not used, the high-precision current mode reference voltage source iscompatible to a CMOS process, layout area is greatly reduced, the production cost is reduced, the power consumption is low, and meanwhile, the power supply rejection ratio is high, and the temperature drift coefficient is low.

A method for predict that life of momentum wheel includes such step as:1, taking power consumption of momentum wheel as characteristic performance parameter of momentum wheel, establish a performancedegradation model of a momentum wheel by one-dimensional Wiener process; 2, obtaining that drift coefficient and the diffusion coefficient in the performance degradation model of the momentum wheel byadopting a maximum likelihood estimation method; Step S3, setting the performance failure threshold of the momentum wheel, and obtaining the expectation and variance of the life of the momentum wheelaccording to the failure threshold. The invention solves the problem that, due to the restriction of the cost and the progress, the life test of the large sample and the long time can not be carriedout on the ground, and the statistical conclusion that it is difficult to obtain the failure data required for the life prediction can not accurately evaluate the life of the momentum wheel with longlife.

The invention discloses a single shaft coupling bearing unit motor and a flexible gyroscope formed by the motor. The single shaft coupling bearing unit motor comprises a supporting system which is mainly composed of a high-precision shaft coupling bearing and a lower end bearing, the structural rigidity of the supporting system is improved, the friction torque of the operation of the motor is reduced, the stability and the rotation precision of the rotating axis of the motor are improved, the drift factor of the gyroscope is reduced, and the working life is prolonged. A dumbbell type symmetrical structure is adopted in the flexible gyroscope, a gyrorotor is supported by adopting a high-precision flexible connector, an overall fly wheel and high-performance permanent magnet alloy form a closed magnetic circuit, the structure of a torquer is optimized, electromagnetic interference torque is reduced, the adjustment of air gap damping torque generated by the rotation of a rotor is facilitated, and the drift coefficient value is adjusted.

The invention relates to an exponential compensation-based low-temperature-drift high-power-source rejection ratio band-gap reference circuit. The circuit comprises a pre-voltage stabilization module,a pre-voltage stabilization starting module, a band-gap reference core module and a band-gap reference core starting module; the band-gap reference core module is used for generating a reference voltage; a fifteenth PMOS transistor of a common source connection method forms a beta help structure, and therefore, the problem of excessively large error induced by base current due to a too small betavalue in a CMOS process is avoided; the high-order curvature compensation structure of the reference voltage is embedded into the beta help structure through a ninth resistor R9, so that the temperature drift coefficient of a reference output voltage is remarkably reduced; the band-gap reference core starting module is used for separating the band-gap reference core module from a degeneracy point; the pre-voltage stabilization module is used for generating local voltages for supplying power for the band-gap reference core module and the band-gap reference core starting module; by means of a self-adaptive driving structure, the driving capability of a pre-voltage stabilization structure is guaranteed, and the power supply rejection ratio of the reference output voltage is effectively improved; the pre-voltage stabilization starting module is used for separating the pre-voltage stabilization module from a degeneracy point.

The invention relates to an improved catalytic combustion gas sensor and a gas detecting method. The catalytic combustion gas sensor comprises a first resistor, a second resistor and a black component. The head of the first resistor is connected to the power supply voltage. The tail end of the first resistor is connected to the head of the second resistor. The tail end of the second resistor is connected to one end of the black component and the tail end of the second resistor end is grounded. The catalytic combustion gas sensor is characterized in that the sensor comprises a sampling element,the head end of the sampling element is connected to the power supply voltage, the tail end of the sampling element is connected to the other end of the black component and the resistance of the sampling element is 1 / N times the thermal resistance of the black component, wherein N is greater than 1. Through acquiring a concentration of preliminary gas to be detected and a zero drift coefficient and a sensitivity drift coefficient of the gas sensor, a compensated gas concentration value is obtained, and through combination of a temperature calibration coefficient and a humidity calibration coefficient of the gas sensor, an actual concentration value of the compensated gas to be detected is obtained so that the adverse effects of temperature and humidity factors in the surrounding environment on the results detected by the gas sensor are reduced.

The invention discloses a low-power-consumption band-gap reference circuit with high-order curvature compensation. The band-gap reference circuit comprises a starting circuit, a biasing circuit, an operational amplifier circuit, a generation circuit and a high-order temperature compensation circuit. According to the band-gap reference circuit, compensation is performed on high-order temperature characteristics of emitter junction voltages of PNP-type transistors according to an inherent exponential relation among sub-threshold regions of MOS transistors; under the condition of only adding twoimage currents, compared with a traditional first-order low-voltage band-gap reference circuit, the band-gap reference circuit is low in power consumption, and the level of the power consumption is nanowatt; by the adoption of a curvature compensation technology, the temperature drift coefficient of an output reference voltage is relatively small and is 20ppm / DEG C or below; and when the ambient temperature changes within the range from -20 DEG C to 80 DEG C, the temperature drift is 4.6ppm / DEG C, and the power consumption of the whole band-gap reference circuit is lower than 1uw.

The invention discloses an active atomic clock of a sapphire resonant cavity and a method for fabricating the resonant cavity. The active atomic clock of the sapphire resonant cavity comprises the sapphire resonant cavity, the ratio of the radius b of the outer wall of a sapphire cylinder of the sapphire resonant cavity to the radius a of the wall of an outer metal cavity cylinder is that rho 1 is not less than 0.5 and not more than 0.56; the radius a of the wall of the outer metal cavity cylinder is that a is not less than 85mm and not more than 87.5mm; the radius b of the outer wall of the sapphire cylinder is that b is not less than 42.5mm and not more than 47.6mm; and the radius c of the inner wall of the sapphire cylinder is that c is not less than 36.68mm and not more than 40.6mm, and the height of the cylinder is equal to 162.9mm. SrTiO3 circular rings with the thickness of 2mm are respectively formed on the upper end surface and the lower end surface of the sapphire cavity cylinder of the sapphire resonant cavity. The size of the sapphire resonant cavity is calculated through sapphire resonant cavity and finite software simulation analysis, thereby realizing the maser self-excited oscillations of the sapphire resonant cavity and effectively reducing the volume and the quality of the active hydrogen atomic clock. Furthermore, the temperature drift coefficient of the sapphire resonant cavity can be also reduced.

The invention relates to a voltage reference circuit comprising a band-gap reference module, an operational amplifier, a resistance voltage trimming circuit and a negative temperature coefficient current compensation circuit. The band-gap reference module includes resistors R1-R4 and transistors Q1-Q3. The first input end and the second input end of the operational amplifier are respectively connected to collectors of Q2 and Q3, and the resistance voltage trimming circuit is connected in series between Q1 and R1. The negative temperature coefficient current compensation circuit is connected tothe end of the resistance voltage trimming circuit. The voltage reference circuit introduces the trimming circuit and the negative temperature coefficient current compensation circuit, so that the reference voltage can meet the requirements for progress indexes at any process angle, and the temperature drift coefficient can be effectively improved.

The present invention provides a phase change memory read circuit having a temperature following characteristic. The phase change memory read circuit comprises a reference phase change memory array, a phase change memory array, a reference phase change memory cell address registering module, a reference current generation module, a clamping voltage generation module, and a current comparison module. According to the present invention, by sampling the ambient temperatures of different positions of the large-scale phase change memory array and by using the temperature drift coefficient of the phase change unit in the high and low resistance state, the reference current is changed along with the ambient temperature change so as to provide the proper self-tuning characteristic, such that the temperature difference between different physical positions of the phase change memory array is considered, the aliasing of the reference current value and the phase change unit bit line current value is avoided, and the correct read of the readout circuit during the change of the external environment temperature is improved.

The invention relates to a clock circuit, and provides a crystal-oscillation-free clock circuit which is capable of effectively improving the temperature stability of a clock signal generated by the clock circuit and making the frequency of the clock signal generated by the clock circuit not changed along with the change of outside temperature, and has an extremely low temperature drift coefficient. The crystal-oscillation-free clock circuit is provided with a linear voltage stabilization module, a high-order temperature compensation module and an annular oscillation module, wherein the linear voltage stabilization module is externally connected with power supply voltage; the two same output voltage output end of the linear voltage stabilization module are connected with the input end of the high-order temperature compensation module and the input end of the annular oscillation module respectively; the reference output voltage of the linear voltage stabilization module is connected with the input end of the high-order temperature compensation module; the output end of the high-order temperature compensation module is connected with the input end of the annular oscillation module; and the annular oscillation module outputs a final clock signal.