58results about How to "Reduce temperature drift coefficient" patented technology

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 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 relates to a rotation torque sensor supplying power by the adoption of a dynamic transformer in a coupling mode. The rotation torque sensor supplying the power by the adoption of the dynamic transformer in the coupling mode comprises an elastic rotating shaft. A strain gage is adhered to the shaft body of the elastic rotating shaft; both a signal conditioning and infrared photoelectric emission circuit board and a secondary coil of the dynamic transformer are fixedly arranged on the shaft body of the elastic rotating shaft; both an F / V and V / I conversion circuit board and a primary coil of the dynamic transformer are fixedly arranged on the shell body of a shell; the primary coil of the dynamic transformer is coupled to the secondary coil of the dynamic transformer; two ends of the shell are respectively and fixedly provided with an end cover; the elastic rotating shaft is installed on end covers through bearings; both a primary oscillation drive circuit board of the dynamic transformer and an infrared receiving and pulse shaping circuit board are fixedly arranged on the end covers. The rotation torque sensor supplying the power by the adoption of the dynamic transformer in the coupling mode effectively solves the problems that a purely-photoelectric-type rotation torque sensor supplies power through photocells so as to cause large temperature rise, and meanwhile effectively solves the anti-interference problem of a purely-magneto-electricity-type rotation torque sensor, can output a plurality of types of signals such as frequency signals, current signals and voltage signals, and enlarges application ranges.

The invention discloses a measuring method for an axial centroid of a two-degree-of-freedom gyroscope rotor assembly, and belongs to the technical field of angular rate sensors. The measuring method is characterized by comprising the following steps of S1, putting a gyroscope under an open circuit into a horizontal attitude at which point a gyroaxis is parallel to a plumb line of the ground, and adjusting a zero position of a gyro sensor to a minimum value; S2, putting the gyroscope under the open circuit into an azimuth attitude at which point the gyroaxis is perpendicular to the plumb line of the ground, adjusting the zero position of the gyro sensor to a minimum value by inputting current to a gyrotorquer and recording the current value at this moment as IX; S3, measuring an axial unbalance of the gyroscope D(y)y for the gyroscope under a close circuit; S4, establishing a linear relation between the current value IX and the unbalance D(y)y; S5, utilizing the linear relation to calculate the unbalance D(y)y through the measured current value IX. According to the invention, a gyroscope rotor centroid measurement system is built by using a gyroscope test system of a force feedbackrebalance circuit, thereby mainly solving accurate measurement of an axial centroid position of the gyroscope rotor assembly.

The invention discloses a micro-resonance electrometer based on bending beams having single free ends and a charge detection method. A ground electrode, a substrate, a resonator, a drive electrode, asense electrode, an input electrode, and an anchor end are arranged inside the sensor. Two ends of two bending beams arranged at the resonator are connected mutually to form a fixed end and a detection end; the fixed end is connected with the ground electrode; the detection end is connected with the anchor end by a flexible support beam; and the detection end and the input electrode form a flat plate type input capacitor. Two sides of flat electrodes of the bending beams, together with the drive electrode and the sense electrode, forms a drive capacitor and a sense capacitor. According to theinvention, on the basis of the provided novel design of the bending beams with single free ends, the resonator works in an elastic deformation mode and a novel charge sensing mechanism is provided based on the elastic deformation mode, so that the high sensitivity is realized. Moreover, the nonlinearity influence of the resonator is eliminated and the temperature drift coefficient of the frequencyis reduced.

The invention discloses a low-temperature-drift current source circuit insensitive to a power source. The circuit makes a second MOS pipe always in a normal working state without circuit starting, the voltage influence of the power source on the current going across a second resistor is smaller, correspondingly the influence of power source voltage on the current output by the current source circuit is reduced, and the sensitivity of the current source circuit to the power source is reduced. In addition, in the working process of the current source, threshold voltages of a third MOS pipe and a fourth MOS pipe which are largely influenced by the temperature are mutually offset, accordingly the current going across a third resistor is not influenced by the temperature, the influence of temperature change on the current output by the threshold voltage is thus reduced, and the temperature drift coefficient of the current source circuit is reduced.

The invention relates to a reference voltage source, in particular to a segmented temperature compensation reference voltage source. According to the technical scheme provided by the invention, the segmented temperature compensation reference voltage source comprises a first-order temperature compensation band-gap reference module for simultaneously outputting band-gap reference voltage and negative temperature coefficient triode base-emitter voltage, and further comprises an output driving buffer and a segmented temperature compensation feedback module, the output driving buffer and the segmented temperature compensation feedback module are both adaptively connected with the first-order temperature compensation band-gap reference module, and the segmented temperature compensation feedback module is adaptively connected with the output driving buffer; temperature compensation can be carried out on the band-gap reference voltage, the temperature drift coefficient of the band-gap reference voltage is effectively reduced, the application range is widened, and safety and reliability are achieved.

The invention discloses an ultra-low bias current design method based on a bipolar amplifier and a circuit thereof, and relates to a semiconductor integrated circuit. A real-time sampling current elimination design method is adopted, and an amplifier circuit comprises a starting bias circuit, a common-emitter and common-base input differential circuit and a base current compensation core circuit. The starting bias circuit enables the system to get rid of the constraint of a degeneracy point to work normally after a power supply is powered on, and provides a stable direct current bias point for the system after starting is completed; the common-emitter common-base input differential circuit comprises a same-type super-beta NPN transistor differential pair, and achieves the functions of input signal amplification and double-to-single conversion. The base current compensation core circuit comprises a bias current monitoring circuit and a compensation circuit, input geminate transistor base current copying is achieved through a precise current mirror and negative feedback, and base current synchronous compensation is achieved. The problem that an existing current operational amplifier is too large in input bias current and low in weak signal processing precision is solved. The low-bias current operational amplifier is widely applied to the technical field of low-bias current operational amplifiers.

The invention relates to novel liquid crystal display equipment with a self-protection function. The novel liquid crystal display equipment comprises a liquid crystal display screen and a dust preventing mechanism. The dust preventing mechanism comprises two dust preventing components. Each dust preventing component comprises a rotary shaft, dust preventing cloth and an extension spring, wherein the extension spring is located in the rotary shaft, one end of the dust preventing cloth is fixed in the rotary shaft through the extension spring, and the dust preventing cloth winds the outer periphery of the rotary shaft. The novel liquid crystal display equipment has the advantages that the two dust preventing cloth is tensioned by the extension springs, and dust preventing of the liquid crystal display screen is guaranteed; a fixing block is fixed in position by the aid of a limit component, fixing reliability is guaranteed, and equipment reliability is further increased; in addition, the type of each of a first operational amplifier, a second operational amplifier and a third operational amplifier in a temperature detecting circuit is LMV324, low temperature drift coefficient is achieved, and accordingly circuit signal detection reliability is increased, and equipment reliability is increased.

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.

The invention relates to a band-gap reference circuit, in particular to a band-gap reference circuit suitable for a radio-frequency circuit, and belongs to the technical field of band-gap reference circuits. According to the technical scheme, the band-gap reference circuit suitable for the radio-frequency circuit comprises a self-starting circuit for being connected with a power supply Vdd and a reference circuit connected with the self-starting circuit, and the reference circuit is connected with a buffer load output circuit. After the self-starting circuit is powered on and started, the self-starting circuit can charge the reference circuit; after a voltage in the reference circuit is stabilized, the self-starting circuit is open, the reference circuit can generate an output current Iref irrelevant with temperature, and the buffer load output circuit outputs a voltage stable in strength and range of oscillation according to the output current Iref. The band-gap reference circuit is compact in structure, small in temperature drift coefficient and low in noise, can provide constant low-noise voltage and current for a radio frequency system and is safe and reliable.

An athermal arrayed waveguide grating includes a silicon-based substrate and an athermal arrayed waveguide disposed on the silicon-based substrate. The athermal arrayed waveguide includes a cladding layer and a waveguide chip layer, the waveguide chip layer is disposed on the cladding layer and has a refractive index greater than that of the cladding layer; the waveguide core layer includes multilayer structures having a periodic configuration, the multilayer structure includes two layers of silica material and a negative temperature coefficient material disposed between the two layers of silica material; the negative temperature coefficient material is used to compensate for a dimensional deformation of the silicon-based substrate after being heated. The present invention simplifies the structure of the athermal arrayed waveguide grating, sets the negative temperature coefficient material in the waveguide core layer structure, and makes the final temperature coefficient of refractive index of the waveguide structure is a negative number.

Low temperature drift high power supply rejection ratio bandgap reference circuit based on exponential compensation, including pre-regulation module, pre-regulation start-up module, bandgap reference core module and bandgap reference core start-up module, the bandgap reference core module is used to generate reference voltage , the fifteenth PMOS tube with common source connection forms a βhelp structure, which avoids the problem of too small a value of β in the CMOS process, which causes excessive errors in the base current; at the same time, the high-order curvature of the reference voltage is compensated by the ninth resistor R9 The structure is embedded in the βhelp structure, which significantly reduces the temperature drift coefficient of the reference output voltage; the bandgap reference core startup module is used to make the bandgap reference core module break away from the degeneracy point; the pre-regulator module is used to generate a bandgap reference core module The local voltage supplied by the bandgap reference core start-up module, through the self-adaptive drive structure, not only ensures the driving capability of the pre-regulation structure but also effectively improves the power supply rejection ratio of the reference output voltage; the pre-regulation start-up module is used to make the pre-stabilization The compression module leaves the degeneracy point.

The invention relates to an interface circuit of a differential capacitance micro vibrating sensor. The interface circuit is composed of a power supply voltage stabilizing circuit, a square wave exciting circuit, a C-V conversion circuit, an amplification filter circuit and a micro vibrating sensor sensing element. The interface circuit is in a single-supply power supply mode; and diodes D1 and D2 and capacitors C4 and C5 are employed inside the interface circuit to supply power for internal devices. A square wave excitation signal is generated by an RC crystal oscillator and passes through aresistor Rs1; and then the square wave excitation signal is divided into two paths of signals that respectively pass through a capacitor Cn1 and a capacitor Cn2; and charging and discharging are carried out on sensitive capacitors Cs1 and Cs2. The C-V conversion circuit linearly converts a differential capacitor delta C into a single-voltage signal Vsense; and then amplification and filtering arecarried out on the single-voltage signal Vsense and then the processed signal is output. According to the invention, the principle is simple and there is no large-scale integrated chip; and cost is low as well as miniaturization and low power consumption are easy to realize. The design is flexible; and temperature compensation, zero adjustment, and positive and negative sensitivity adjustment andthe like can be respectively carried out. And precision of detection on a weak signal generated by the differential capacitance micro vibrating sensor is high; a noise level is low; and stability is good.