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.

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

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.