34 results about "Zero temperature coefficient" patented technology

The present invention discloses a negative temperature drift bandgap reference circuit suitable for a large dynamic range logarithmic amplifier. The circuit relates to the field of integrated circuit technology and includes a startup circuit for providing a startup current; and a reference core circuit comprising a plurality of transistors and a plurality of resistors, the transistors being electrically connected to the resistors. The reference core circuit is configured to provide a reference voltage with a negative temperature coefficient, biasing a rectifier, thereby ensuring an extremely low DC bias current temperature coefficient of the rectifier at temperatures between -55°C and 125°C. Compared to conventional zero temperature coefficient bandgap reference circuits, the present invention is more suitable for large dynamic range logarithmic amplifiers, enabling them to exhibit excellent temperature characteristics, including slope and logarithmic consistency error.

The invention discloses a composite material with a near-zero temperature coefficient. The composite material comprises composite particles with three layers of core shells, the composite particle comprises a metal organic framework serving as an inner core, a conductive carbon transition layer serving as a middle layer and a gradient doped tin oxide layer serving as a shell, and the resistance temperature coefficient symbols of materials of the inner core and the shell are opposite within the range of 0-80 DEG C. According to the composite material with the near-zero temperature coefficient, a three-layer core-shell structure of a metal organic framework core / a conductive carbon transition layer / a gradient doped SnO2 shell is adopted, mutual offset of temperature coefficients can be achieved in the material, and therefore drifting of baseline resistance generated along with fluctuation of the environment temperature is reduced.

The present application relates to a clock signal generating device and an integrated circuit. The device includes: an oscillation module configured to provide a plurality of clock signals in response to an enable signal. The oscillation module includes: a first oscillation unit including a resistor device having a negative temperature characteristic and configured to generate a first clock signal having a first phase, and a second oscillation unit including a resistor device having a positive temperature characteristic and configured to generate a second clock signal having a second phase. The first oscillation unit generates a third clock signal under the influence of the second clock signal, and the second oscillation unit generates a fourth clock signal under the influence of the first clock signal. The first to fourth clock signals have the same temperature characteristic; a clock output module coupled to the oscillation module and configured to generate a corresponding clock signal group based on the plurality of clock signals. The solution of the present application can generate a frequency with zero temperature coefficient, has good temperature stability, and at the same time the frequency is adjustable and the temperature characteristic is adjustable.

The utility model relates to a zero temperature coefficient generation circuit capable of inhibiting process drift, and aims to improve the process anti-interference performance and the temperature stability of reference current. The circuit comprises a reference circuit, an operational amplifier, a first MOS tube, a second MOS tube, a first resistor and a second resistor. Stable reference voltage is provided through the reference circuit, and the operational amplifier adjusts the grid voltage of the first MOS tube so as to control the precision of current. Meanwhile, the second resistor and the first resistor are of the same type, so that the resistance change influence caused by process drift is offset, and the output current is further stabilized. The circuit can be integrated in an analog-digital hybrid chip, the cost is saved, and the overall circuit performance is improved.

This invention discloses an air conditioning device that determines the initial and equilibrium temperatures of a power module; controls the compressor's operating state to ensure the IGBT output current has a relative zero temperature coefficient; determines the total power module losses at the equilibrium temperature based on the IGBT's relative zero temperature coefficient parameters; acquires the thermal resistance of the inverter driver and refrigerant radiator, and determines the theoretical temperature based on the thermal resistance and total losses; determines the theoretical temperature rise based on the theoretical and initial temperatures, and determines the measured temperature rise based on the equilibrium and initial temperatures; determines the deviation value based on the theoretical and measured temperature rises; acquires the standard deviation value, and compares the deviation value with the standard deviation value to determine whether the refrigerant radiator is qualified. The air conditioning device can intelligently assess the reliability of the refrigerant radiator and its installation.

The invention relates to a relaxation oscillator irrelevant to oscillation frequency and temperature. The relaxation oscillator comprises a reference module, a bias current source module and an oscillator core circuit module, the reference module is used for outputting zero temperature coefficient current; the bias current source module is used for finely adjusting the zero temperature coefficient current and outputting the zero temperature coefficient current after fine adjustment; and the oscillator core circuit module is used for charging and discharging the capacitor C by taking the fine-tuned zero temperature coefficient current as a charging and discharging current. According to the invention, the change rate of the current at-40 DEG C to 125 DEG C along with the temperature can be controlled below + / -0.6%.

The invention discloses a control voltage generation method and circuit for a voltage-controlled oscillation circuit. The control voltage generation method comprises the following steps: obtaining a first differential current between a zero temperature coefficient current and a first positive temperature coefficient current; compensating the first differential current by a compensation current to provide a control current; and providing a control voltage according to the control current and the corresponding target conversion gain, the compensation current being zero in the second temperature interval and being zero in the third temperature interval when the control voltage is not changed, and the compensation current being zero in the second temperature interval when the control voltage is not changed. The change rate of the oscillation frequency in the first temperature interval and the third temperature interval along with the temperature is larger than the change rate in the second temperature interval. According to the control voltage generation method and circuit provided by the invention, the oscillation frequency of the voltage-controlled oscillation circuit does not change along with the temperature change through the self-adaptive temperature compensation of the control voltage, and the reliability of the voltage-controlled oscillation circuit is improved.

This invention provides a soft-start circuit, relating to the field of electronic and electrical technology. It includes a constant current source module that outputs a zero-temperature coefficient nA-level constant current; a constant current charging module that linearly charges a soft-start capacitor with a constant current, generating a linearly rising soft-start reference voltage; a feedback control module that clamps the output sampling voltage to the reference voltage through a negative feedback loop, ensuring a smooth rise in output voltage; a low-power logic control module that shuts down the constant current charging and feedback control modules after soft-start; and a gate drive module that drives the power devices to conduct. The advantages include using a zero-temperature coefficient nA-level current combined with negative feedback clamping to solve the problems of temperature drift, unstable charging slope, and low control accuracy in traditional RC structures; shutting down related modules after soft-start, combined with a low-current design to reduce static power consumption; and the ability to integrate the circuit on a standard process chip without external components, reducing system size and cost.

The invention relates to a low-noise reference circuit based on a Zener diode, which is composed of a PTAT current generating circuit, a CTAT current generating circuit and a temperature coefficient eliminating circuit, the Zener diode adopts built-in bias current, in the circuit, positive temperature characteristics and negative temperature characteristics of different components are fully utilized to offset each other, and in the circuit, the positive temperature characteristic and the negative temperature characteristic of the CTAT current generating circuit are utilized to offset each other; and secondly, a negative feedback circuit is designed to correct the working state of the Zener diode in real time, and it is ensured that the Zener diode works in a linear state and operates stably. And low-temperature drift, high-linearity and high-precision output of the circuit is realized.

The invention discloses a front-end detection circuit of a high-precision temperature sensor. The front-end detection circuit comprises a biasing and starting module, a temperature sensing core module, an output module and a high-order temperature compensation module. The starting module activates the core temperature sensing circuit when the power supply is powered on. The temperature sensing core module takes a BJT as a temperature sensing element and generates positive and negative temperature coefficient voltage. The output module generates a zero temperature coefficient reference voltage and a positive temperature coefficient voltage. And the high-order temperature compensation module realizes temperature compensation by generating currents with different temperature characteristics, so that the measurement precision is improved.

The invention relates to a device structure for reducing the zero temperature coefficient voltage of a SiC MOSFET (Metal-Oxide-Semiconductor Field Effect Transistor) transfer characteristic curve and a preparation method of the device structure. The device structure sequentially comprises a substrate (1), an N-drift region (2), a current expansion layer (3) and a jfet region (4), a pwell region (5) is formed on the N-drift region (2) through ion implantation; n ion implantation is carried out on the pwell region (5) to form an nplus region (6), and Al ion implantation is carried out on the pwell region (5) to form a pplus region (7). According to the invention, the zero temperature coefficient voltage is effectively reduced through the structural design, which is of great significance to SiC MOSFETs.

This invention discloses a frequency converter driver testing device that determines the initial temperature and equilibrium temperature of a power module; determines the total power module loss at the equilibrium temperature based on the IGBT's relative zero temperature coefficient parameters, current, and voltage; obtains the frequency converter driver's thermal resistance and determines the theoretical temperature based on the thermal resistance and total loss; determines the theoretical temperature rise based on the theoretical temperature and initial temperature, and determines the measured temperature rise based on the equilibrium temperature and initial temperature; determines the deviation value based on the theoretical temperature rise and measured temperature rise; obtains the standard deviation value, and compares the deviation value with the standard deviation value to determine whether the heat sink and power module assembly is qualified. The testing device determines the deviation value by comparing the theoretical temperature change estimated from the power module loss under a specific state and the thermal resistance with the actual temperature change of the power module, and compares this deviation value with a pre-determined standard deviation value to determine whether the heat sink and power module assembly is qualified. This allows for intelligent assessment of the reliability of the power module and heat sink installation.

A method for generating a constant current. The method can include receiving an input voltage at a voltage input connected to a resistor pair, the resistor pair including a first resistor and a second resistor, the first resistor having a positive temperature coefficient and the second resistor having a negative temperature coefficient. The first and second resistors can be configured such that the variability of resistance over temperature of the first resistor and the variability of resistance over temperature of the second resistor cancel to produce a zero temperature coefficient for the resistor pair. The method can further include applying the input voltage to the resistor pair to generate a current with a zero temperature coefficient.

The invention discloses a method and equipment for controlling back bias output zero temperature coefficient current, relates to the technical field of integrated circuits, and is used for solving the problem that the current temperature coefficient of a target transistor cannot be flexibly regulated and controlled in the prior art. Comprising the following steps: configuring a band-gap reference circuit; simulating a target transistor in the band-gap reference circuit, and determining the size and bias voltage of the transistor meeting a preset condition; performing voltage division processing on the band-gap reference circuit to determine a target back gate voltage; and applying the target back gate voltage to the back gate end of the target transistor, iteratively updating the transistor size and the target back gate voltage, and outputting a current meeting the zero temperature coefficient requirement. According to the technical scheme provided by the invention, better temperature performance can be realized, and the complexity of circuit design is reduced; flexible back bias voltage is provided, and more choices are provided for circuit design.

The application discloses a reference current temperature compensation circuit and a reference current temperature compensation control method, and the reference current temperature compensation circuit comprises a PTAT current generation circuit, a temperature compensation module and a CTAT current output module; the PTAT current generation circuit is used for generating a PTAT current; the temperature compensation module is used for generating a temperature coefficient current; and the CTAT current output module is used for outputting to a set output end through current mirror mirroring. The reference current temperature compensation circuit and the reference current temperature compensation control method can complete the temperature compensation of the current by using a few devices without affecting the reference voltage in the band gap reference circuit, obtain a reference current with zero temperature coefficient, or directly generate a reference current with zero temperature coefficient by using a PTAT current, thereby saving the area of the chip and reducing the production cost to a certain extent. In addition, the current has high stability and is less affected by a power supply voltage, and can well adapt to market needs.

The application discloses a band gap reference voltage circuit, and relates to the field of circuit design, which comprises a positive and negative temperature coefficient voltage generating circuit, a temperature coefficient compensation circuit and a voltage dividing circuit. The positive and negative temperature coefficient voltage generating circuit generates positive temperature coefficient voltage and negative temperature coefficient voltage. The temperature coefficient compensation circuit generates zero temperature coefficient voltage based on the positive temperature coefficient voltage and the negative temperature coefficient voltage. The voltage at the first end of the voltage dividing circuit is the zero temperature coefficient voltage. The second end of the voltage dividing circuit is grounded. The reference voltage is less than the zero temperature coefficient voltage by adjusting the voltage division between the first end and the voltage dividing end and between the second end and the voltage dividing end in the voltage dividing circuit, so that the loss of a digital circuit working with the reference voltage provided by the band gap reference voltage circuit is reduced.

An integrated circuit includes a memory and peripheral circuits with a temperature sensor used to automatically adjust operating voltages. The temperature sensor includes a reference circuit that generates a first reference with a first non-zero temperature coefficient and a second reference with a second temperature coefficient having a different magnitude than the first non-zero temperature coefficient. A detector circuit on the integrated circuit, having temperature and process variation compensation, converts a difference between the first and second references into a digital signal indicating temperature on the integrated circuit.

The invention provides an intermediate dielectric microwave ceramic material with a near-zero temperature coefficient and a preparation method thereof, and relates to the field of ceramic materials. The material comprises the following components in percentage by weight: 97 to 98.5 percent of main crystal phase, 0.1 to 1.0 percent of Mg-Ca-Si-O glass phase and 0.5 to 2.5 percent of modified additive (selected from BaCO3, SrCO3 and the like), the core chemical formula of the main crystal phase is (MxCaLnz) TiO3, and during preparation, Mg / Zn salt, Ca salt, rare earth and TiO2 are mixed and calcined for 1-4 h at the temperature of 1050-1250 DEG C, and the main crystal phase is obtained; melting the Mg-Ca-Si-O mixture, and performing water quenching to obtain a glass phase; the three components are mixed in proportion, molded under 10MPa, and sintered at 1280-1400 DEG C for 2-5 hours. The room temperature dielectric constant of the material is 25-33, Qf is larger than or equal to 25000GHz, tau f (-40-110 DEG C)-10-30ppm / DEG C is adjustable, the cost is low, the sintering applicability is high, the requirements of microwave devices are met, the overall preparation steps are simple, key parameters (temperature, time, pressure and the like) are definite, the repeatability is good, and the industrial stable production requirements can be met.

Aspects of the present disclosure include a scalable proportional to absolute temperature (PTAT) hybrid circuit, comprising a bias mirror circuit configured to provide a zero temperature coefficient (ZTC) current, a PTAT control circuit configured to generate, based on the ZTC current, a PTAT current with a slope having a non-zero value, alter the PTAT current by at least scaling the PTAT current or changing the slope of the PTAT current to generate an altered PTAT current, and provide the altered PTAT current, a hybrid circuit configured to receive the ZTC current and the altered PTAT current, and output a larger current of the ZTC current and the altered PTAT current as a hybrid current.

The application discloses a high-precision voltage stabilizing source circuit with zero temperature coefficient, and relates to the field of voltage stabilizing source circuits.The method comprises a voltage stabilizing unit, a first current source unit and a second current source unit which are adaptively connected.The first current source unit is used for generating a first current I1 with a positive temperature coefficient, and the second current source unit is used for generating a second current I2 with a negative temperature coefficient.Based on the first current I1, the second current I2 and element parameters of the voltage stabilizing unit, the voltage stabilizing unit generates a reference voltage VREF with zero temperature coefficient.The voltage stabilizing source circuit has zero temperature coefficient and higher output precision.

The invention discloses a zero-temperature-drift resistance circuit and a trimming method, relates to the technical field of integrated circuits, and aims to solve the problem that a resistance circuit in the prior art cannot realize low resistance, zero temperature drift, high precision and reduction of occupied area at the same time. The circuit comprises a main resistor network, a first trimming resistor network and a second trimming resistor network, the main resistor network is connected in parallel with the first trimming resistor network and then is connected in series with the second trimming resistor network; the trimming precision of the first trimming resistor network is smaller than that of the second trimming resistor network; trimming resistor units in the main resistor network and the first trimming resistor network are zero temperature coefficient resistor units; therefore, the main resistor network, the first trimming resistor network and the second trimming resistor network can be utilized to perform step-by-step trimming, and a resistance value adaptive to the target resistor is obtained and then output. And low resistance, zero temperature excursion and high precision are realized while the occupied area of the chip is reduced.

The invention relates to a high-precision segmented compensation band-gap reference circuit, which comprises a first-order reference core module used for enabling the voltage difference between the base electrode and the emitter electrode of a triode to act on a resistor R3, acquiring current flowing through the resistor R3, inputting the current into a self-bias current circuit, and outputting a reference voltage source VREF according to compensation current output by a temperature compensation module; the self-bias current circuit is used for generating self-bias reference current, taking the self-bias reference current as zero temperature coefficient current, taking the current flowing through the resistor R3 as positive temperature coefficient current, combining the positive temperature coefficient current and the zero temperature coefficient current in proportion, and inputting the positive temperature coefficient current and the zero temperature coefficient current into the temperature compensation module; and the temperature compensation module is used for outputting compensation current according to the combined current. According to the invention, the sensitivity of the reference voltage to process deviation and power supply fluctuation is obviously reduced.

This invention provides a porous carbon-based nanocomposite material with intrinsically zero temperature coefficient, its preparation method, and a flexible pressure sensor with intrinsically zero temperature coefficient, belonging to the field of flexible pressure-sensitive materials technology. This invention uses PDMS as a flexible matrix and carbon black and carbon nanotubes as conductive fillers. It innovatively constructs a uniform and controllable pore structure within the material through a chemical foaming method that generates gas by the in-situ reaction of sodium bicarbonate and hydrochloric acid. Unlike existing technologies that rely on circuit compensation, this invention achieves precise cancellation of the positive and negative temperature coefficient effects of the material over a wide temperature range by synergistically controlling the ratio of carbon black to carbon nanotubes and the porosity of the material, thus obtaining a porous carbon-based nanocomposite material with intrinsically zero temperature coefficient. The preparation temperature and energy consumption are low, the process is simple and controllable, and the relative change rate of the material's resistance is less than 2% in the range of 25~100℃. When used in a flexible pressure sensor, it does not rely on external compensation circuits and exhibits both excellent piezoresistive sensitivity and temperature stability.

The application discloses a CMOS voltage reference source adopting a self-elimination technology of a disordered voltage, comprising a bias circuit, an operational amplifier circuit and a zero-temperature coefficient bias circuit; the bias circuit adopts a 1uA current source to provide a bias voltage for a subsequent circuit, so that the subsequent circuit can normally work under a power supply voltage of 0.65V to 2.5V; the operational amplifier circuit locks the output voltage of the zero-temperature coefficient bias through a two-stage folded common-source common-gate operational amplifier; and the zero-temperature coefficient bias circuit realizes working at a zero-temperature coefficient point by adjusting the bias point of MN25, and realizes the output of the voltage reference source. The CMOS voltage reference source can work in a wide voltage range and is not affected by the disordered voltage of the operational amplifier.

The high-precision oscillator circuit based on the temperature compensation array comprises an operational amplifier OP1, a transistor MN1, a comparator array, a reference voltage setting resistor array and an oscillator module, the positive input end of the operational amplifier OP1 is connected with a band-gap reference voltage source VREF, the output end of the operational amplifier OP1 is connected with the transistor MN1, and the output end of the operational amplifier OP1 is connected with the comparator array. The inverted input end of the operational amplifier OP1 is connected with the reference voltage setting resistor array and the source electrode of the transistor MN1, the drain electrode of the transistor MN1 is connected with voltage VI N, and the reference voltage setting resistor array is formed by connecting a plurality of resistors in series. According to the utility model, the positive temperature coefficient resistor and the negative temperature coefficient resistor are cooperatively used, the temperature detection array is combined, the two temperature coefficients are adjusted, the whole temperature coefficient is compensated, and the zero temperature coefficient characteristic is theoretically realized, so that the low temperature drift characteristic is obtained.

The invention relates to a self-biasing and temperature compensation band-gap reference power supply which comprises a PTAT current generation circuit, a temperature coefficient elimination circuit, a divider resistance network and a resistance network current generation circuit. The power supply circuit is powered by VDD, and the PTAT current generating circuit generates PTAT current through a positive feedback loop. In a temperature coefficient elimination circuit, a self-biased reference current is adopted to provide a bias current for a Zener diode, and a bias current with a zero temperature coefficient is designed to provide a path of bias current for the Zener diode. A negative feedback circuit is introduced into the resistance network current generation circuit to provide another path of configuration current for the Zener diode, and it is ensured that the Zener diode works in a reverse breakdown region and operates stably. And the output precision is improved while positive and negative temperature coefficients are eliminated. The circuit provided by the invention has the advantages of high cost performance, high output precision and good temperature drift characteristic, the circuit is simplified, the integrated manufacturing is easy, the output noise is low, and the reliability is also remarkably improved.

The utility model discloses an over-temperature protection circuit and a chip. The over-temperature protection circuit comprises a current supply module, a cascode current mirror, a trim resistor and a voltage comparison module. The current providing module is used for providing current with a zero temperature coefficient; the cascode current mirror is used for carrying out mirror image processing on the current with the zero temperature coefficient and outputting the current with the zero temperature coefficient to a first end of the trim resistor; the trim resistor is used for converting the current with the zero temperature coefficient into detection voltage and outputting the detection voltage to a first input end of the voltage comparison module; the voltage comparison module is used for outputting an over-temperature indication signal according to the detection voltage and the reference voltage. The over-temperature protection circuit provided by the utility model has higher over-temperature detection precision, and the safety of the chip in the working process can be further improved.

The embodiment of the invention provides a current source circuit and an oscillator. The current source circuit comprises a positive temperature coefficient current generating circuit, a negative temperature coefficient current generating circuit and a current summing circuit, the positive temperature coefficient current generating circuit is connected with the negative temperature coefficient current generating circuit and the current summing circuit. The current generator generates positive temperature coefficient current; the negative temperature coefficient current generating circuit is connected with the current summing circuit; the negative-temperature-coefficient current generator generates negative-temperature-coefficient current. The current summing circuit is respectively connected with the positive temperature coefficient current generating circuit and the negative temperature coefficient current generating circuit; and the current mirroring module is used for mirroring the positive temperature coefficient current and the negative temperature coefficient current according to a corresponding preset proportion, summing the mirrored positive temperature coefficient current and the mirrored negative temperature coefficient current, generating a zero temperature coefficient current and outputting the zero temperature coefficient current. The magnitude of the zero temperature coefficient current is not kept constant along with the temperature change, so that the problems that the output current changes obviously along with the temperature and the temperature characteristic is poor are solved.

The application belongs to the field of analog integrated circuit design, and particularly relates to a band gap reference circuit based on high-order temperature compensation. The application only uses two operational amplifiers, and twice uses the clamping function of the operational amplifier. Firstly, a PTAT current with a first-order coefficient is generated through the voltage difference of the emitter-base voltages of two bipolar transistors, and then a CTAT current with a logarithmic coefficient is generated, and a PTAT current with a logarithmic coefficient is further obtained. Then, the two kinds of PTAT currents are respectively converted into a voltage with a first-order positive temperature coefficient and a voltage with a logarithmic positive temperature coefficient by using resistors, and the first-order negative temperature coefficient and the logarithmic negative temperature coefficient of the emitter-base voltage of the bipolar transistor are compensated by using the two kinds of positive temperature coefficient voltages. Finally, a reference output voltage with zero temperature coefficient is obtained. The application is realized by using a 0.18 mu m process, can be industrialized, and is more universal in application range, and is not affected by temperature, power voltage and process fluctuation.

The application provides a bias voltage temperature coefficient adjusting circuit, which comprises a first current branch, a voltage adjusting branch and a second current branch. The first current branch is used for providing a first zero-temperature-coefficient current with adjustable size and a first node voltage. The voltage adjusting branch is used for providing a zero-temperature-coefficient voltage. The second current branch is used for providing a second zero-temperature-coefficient current with adjustable size and generating a bias voltage according to the first node voltage and the zero-temperature-coefficient voltage. The temperature coefficient of the bias voltage is adjusted by the ratio of the first zero-temperature-coefficient current to the second zero-temperature-coefficient current. The application can ensure that a transistor is kept in a saturation region and the performance of a chip is ensured.