A field effect transistor threshold voltage control system and control device

Abstract

The present invention relates to the field of electronic circuit technology, and in particular to a field-effect transistor threshold voltage control system and control device. The system comprises a main feedback loop for acquiring the actual value of the threshold voltage of the field-effect transistor, comparing the actual value of the threshold voltage with a set value to obtain a deviation signal, and sending the deviation signal to a control module; a secondary feedback loop for acquiring the current change rate of the field-effect transistor, and sending the current change rate to the control module; and a control module for generating a control signal based on the deviation signal and the current change rate, and adjusting the gate voltage of the field-effect transistor based on the control signal to control the threshold voltage of the field-effect transistor. The present invention uses the main feedback loop and the secondary feedback loop to collaboratively acquire the voltage deviation signal and current change rate of the field-effect transistor to dynamically adjust the gate voltage of the field-effect transistor, thereby improving control accuracy.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic circuits, and in particular to a threshold voltage control system and control equipment of a field effect transistor. Background Art

[0002] In modern semiconductor integrated circuit applications, precise control of the threshold voltage of field-effect transistors (FETs) directly impacts chip performance and reliability. As chip operating frequencies increase to multiple GHz and operating temperature fluctuations expand to -40°C to 125°C, traditional single-feedback-loop threshold voltage control techniques are gradually exposing significant drawbacks.

[0003] Existing single-feedback systems achieve threshold control by simply measuring the gate-source voltage and comparing it to a preset reference value, adjusting the gate voltage. However, these systems suffer from two core issues: First, they suffer from slow dynamic response. When a sudden change in circuit load causes rapid changes in drain current, the single feedback loop cannot detect the current's dynamic trend in a timely manner. Control signal delays can reach 50-100ns, resulting in delayed threshold voltage adjustment and circuit signal distortion. Second, control accuracy is insufficient. In the face of interference factors such as temperature drift and process variations, a single feedback loop struggles to establish a multivariable compensation mechanism. The measured threshold voltage fluctuates by as much as ±200mV, failing to meet the device consistency requirements of high-performance chips.

[0004] In summary, the technical problem actually solved by the present invention is how to improve the control accuracy of the threshold voltage of the field effect transistor. Summary of the Invention

[0005] In order to overcome the technical defect of low threshold voltage control accuracy of the above-mentioned field effect transistor, the purpose of the present invention is to provide a threshold voltage control system and control device of the field effect transistor, which collaboratively collects the voltage deviation signal and current change rate of the field effect transistor through a main feedback loop and a sub-feedback loop to dynamically adjust the gate voltage of the field effect transistor, thereby improving the control accuracy.

[0006] The present invention discloses a threshold voltage control system of a field effect transistor, comprising a main feedback loop, a sub-feedback loop, a field effect transistor and a control module; wherein,

[0007] The main feedback loop is connected to the field effect transistor and the control module. The main feedback loop is used to obtain the actual value of the threshold voltage of the field effect transistor, compare the actual value of the threshold voltage with the set value to obtain a deviation signal, and send the deviation signal to the control module;

[0008] The auxiliary feedback loop is connected to the field effect transistor and the control module, and the auxiliary feedback loop is used to collect the current change rate of the field effect transistor and send the current change rate to the control module;

[0009] The control module is used to generate a control signal according to the deviation signal and the current change rate, and adjust the gate voltage of the field effect transistor according to the control signal to control the threshold voltage of the field effect transistor.

[0010] Preferably, the main feedback loop comprises an adaptive PID controller;

[0011] The adaptive PID controller uses a deep learning algorithm and dynamically adjusts the proportional coefficient based on historical threshold voltage and deviation signals. , integral coefficient , differential coefficient ;

[0012] The deep learning algorithm uses a convolutional neural network to pre-process the historical threshold voltage and deviation signal as input and output a dynamically adjusted proportional coefficient. , integral coefficient , differential coefficient .

[0013] Preferably, the control module is provided with a first current change rate threshold and the second current change rate threshold , and the first current change rate threshold Greater than the second current change rate threshold ;

[0014] The control module changes according to the current rate and the first current change rate threshold and the second current change rate threshold The relationship between them is used to dynamically adjust the control signal;

[0015] When the current change rate Greater than the first current change rate threshold ,When the control module generates a control signal based on the deviation signal and the current change rate, the weight of the current change rate is increased;

[0016] When the current change rate Less than the second current change rate threshold , when the control module generates a control signal according to the deviation signal and the current change rate, the weight of the current change rate is reduced.

[0017] Preferably, the control module further includes a reinforcement learning unit, which dynamically adjusts the first current change rate threshold value through a reward mechanism according to the control signal. and the second current change rate threshold .

[0018] Preferably, the control module further includes a signal processing unit and a driving unit; wherein,

[0019] The signal processing unit uses a digital signal processor, which is connected to the main feedback loop and the auxiliary feedback loop respectively to receive the deviation signal and the current change rate, and generate a preliminary control signal according to a preset algorithm. The algorithm calculation formula is: ,

[0020] in, Represented as the preliminary control signal, 、 、 They are respectively expressed as the proportional coefficient, integral coefficient and differential coefficient of the PID algorithm in the signal processing unit, Represented as a deviation signal, Expressed as the rate of change of the deviation signal, Expressed as the feedback coefficient of the secondary feedback loop, Expressed as the temperature compensation coefficient, Expressed as the difference between the current temperature and the reference temperature;

[0021] The driving unit is used to convert the preliminary control signal into a control signal capable of driving the gate of the field effect transistor.

[0022] Preferably, it also includes a temperature compensation module and a stress compensation module; wherein,

[0023] The temperature compensation module is preset with a temperature threshold voltage compensation curve, and the stress compensation module is preset with a stress threshold compensation model;

[0024] A temperature compensation module is connected to the field effect transistor and is used to obtain the operating temperature of the field effect transistor and to correct the set value according to the operating temperature and temperature threshold voltage compensation curve; and / or a stress compensation module is connected to the field effect transistor and is used to obtain the mechanical stress on the field effect transistor package and to correct the set value according to the mechanical stress and stress threshold compensation model;

[0025] The temperature threshold voltage compensation curve is established by the following formula: ,

[0026] in, Indicates the set value of the threshold voltage after correction, Expressed as the uncorrected threshold voltage setting, Expressed as the temperature coefficient, Indicates the operating temperature obtained by the temperature compensation module, Expressed as reference temperature;

[0027] The stress threshold compensation model is established by the following formula: ,

[0028] in, It is expressed as the set value of the threshold voltage after considering stress compensation, Expressed as stress coefficient, The mechanical stress values ​​are expressed as obtained.

[0029] Preferably, the source of the field effect transistor is grounded, the drain is connected to the load circuit, and the gate is connected to the output terminal of the control module;

[0030] A variable capacitor is connected in series between the gate of the field effect transistor and the output terminal of the control module. The variable capacitor is used to adjust the voltage change rate of the gate of the field effect transistor. The capacitance value of the variable capacitor is dynamically adjusted according to the current change rate. The adjustment formula is: ,

[0031] in, C It is expressed as the capacitance value of the variable capacitor after adjustment, Represents the initial capacitance value of the variable capacitor, Expressed as the adjustment coefficient.

[0032] Preferably, the main feedback loop further includes a voltage sampling subcircuit and an analog-to-digital conversion subcircuit; wherein,

[0033] The voltage sampling subcircuit is used to collect the actual value of the threshold voltage of the field effect transistor, and the analog-to-digital conversion subcircuit is used to convert the actual value of the threshold voltage into a digital signal for processing by the control module;

[0034] The voltage sampling subcircuit adopts a differential sampling method and is provided with an anti-aliasing filter. The cutoff frequency of the anti-aliasing filter is adaptively adjusted according to the operating frequency of the field effect transistor.

[0035] Preferably, the secondary feedback loop further includes a current sampling subcircuit and a differential operation subcircuit; wherein,

[0036] The current sampling subcircuit is used to collect the current of the field effect transistor, and the differential operation subcircuit is used to calculate the rate of change of the current;

[0037] The current sampling subcircuit uses a Hall current sensor and is equipped with an error compensation subcircuit. The error compensation subcircuit calculates the error based on the temperature and the offset characteristics of the Hall element: Correct the collected current value;

[0038] in, Expressed as the corrected current value, Expressed as the measured current value, Expressed as the temperature error compensation coefficient, Expressed as the offset error compensation coefficient, O Expressed as the offset of the Hall element.

[0039] A second object of the present invention is to provide a threshold voltage control device for a field effect transistor, which includes at least one control system as described above.

[0040] After adopting the above technical solution, compared with the existing technology, the beneficial effect of the present invention is that the voltage deviation signal and current change rate of the field effect transistor are collaboratively collected through the main feedback loop and the sub-feedback loop to dynamically adjust the gate voltage of the field effect transistor, thereby improving the control accuracy and the response speed. It can quickly adapt to complex and changeable working environments, effectively reduce the impact of interference factors such as temperature changes and process deviations on the threshold voltage, and improve the stability and reliability of the field effect transistor. The present invention integrates a temperature compensation module and a stress compensation module, and combines the dual-loop mechanism of the main feedback loop and the sub-feedback loop to form a comprehensive compensation capability for multi-physical field interference. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 The diagram is a control system diagram of a threshold voltage control system and a control device of a field effect transistor according to the present invention. DETAILED DESCRIPTION

[0042] The advantages of the present invention are further described below with reference to the accompanying drawings and specific embodiments.

[0043] Exemplary embodiments will be described in detail herein, with examples illustrated in the accompanying drawings. In the following description, when referring to the drawings, identical numerals in different figures represent identical or similar elements, unless otherwise indicated. The embodiments described in the following exemplary embodiments are not intended to represent all possible embodiments consistent with the present disclosure. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present disclosure, as detailed in the appended claims.

[0044] The terms used in this disclosure are for the purpose of describing specific embodiments only and are not intended to limit the disclosure. As used in this disclosure and the appended claims, the singular forms "a," "an," "the," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should also be understood that the term "and / or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items.

[0045] It should be understood that although the terms first, second, third, etc. may be used in this disclosure to describe various information, such information should not be limited to these terms. These terms are only used to distinguish information of the same type from each other. For example, without departing from the scope of this disclosure, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Depending on the context, the word "if" as used herein may be interpreted as "at the time of" or "when" or "in response to determining."

[0046] In the description of the present invention, it should be understood that the terms "longitudinal", "transverse", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention.

[0047] In the description of the present invention, unless otherwise specified and limited, it should be noted that the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a mechanical connection or an electrical connection, or it can be the internal communication between two components. It can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to the specific circumstances.

[0048] In the following description, the suffixes such as "module", "component" or "unit" used to represent elements are only used to facilitate the description of the present invention and have no specific meaning. Therefore, "module" and "component" can be used interchangeably.

[0049] This embodiment discloses a threshold voltage control system for a field-effect transistor, including a main feedback loop, a sub-feedback loop, a field-effect transistor, and a control module; wherein the main feedback loop is connected to the field-effect transistor and the control module, and is used to obtain the actual value of the threshold voltage of the field-effect transistor, and compare the actual value of the threshold voltage with a set value to obtain a deviation signal, and then send the deviation signal to the control module; the sub-feedback loop is connected to the field-effect transistor and the control module, and is used to collect the current change rate of the field-effect transistor, and send the current change rate to the control module; the control module is used to generate a control signal based on the deviation signal and the current change rate, and adjust the gate voltage of the field-effect transistor based on the control signal to control the threshold voltage of the field-effect transistor.

[0050] See Figure 1 As shown, this embodiment will describe in detail a threshold voltage control system of a field effect transistor, which specifically includes a main feedback loop, a sub-feedback loop, a field effect transistor, and a control module.

[0051] The main feedback loop is connected to the field-effect transistor and the control module. The main feedback loop is used to obtain the actual value of the field-effect transistor's threshold voltage, compare the actual value of the threshold voltage with the set value to obtain a deviation signal, and send the deviation signal to the control module. The secondary feedback loop is connected to the field-effect transistor and the control module. The secondary feedback loop is used to collect the current change rate of the field-effect transistor and send the current change rate to the control module. After passing through the main feedback loop and the secondary feedback loop, the control module will have a deviation signal and current change rate. The control module will generate a control signal based on the deviation signal and current change rate, and then adjust the gate voltage of the field-effect transistor according to the control signal to control the threshold voltage of the field-effect transistor.

[0052] Furthermore, the main feedback loop includes an adaptive PID controller; the adaptive PID controller dynamically adjusts the proportional coefficient based on the historical threshold voltage and deviation signal through a deep learning algorithm. , integral coefficient , differential coefficient The deep learning algorithm uses a convolutional neural network to pre-process the historical threshold voltage and deviation signal as input and output a dynamically adjusted proportional coefficient. , integral coefficient , differential coefficient .

[0053] In this embodiment, the main feedback loop is described in detail. The main feedback loop includes an adaptive PID controller. The adaptive PID controller dynamically adjusts the proportional coefficient based on the historical threshold voltage and deviation signal through a deep learning algorithm. , integral coefficient , differential coefficient The deep learning algorithm uses a convolutional neural network to pre-process the historical threshold voltage and deviation signal as input and output the dynamically adjusted proportional coefficient. , integral coefficient , differential coefficient As a classic control algorithm, the adaptive PID controller consists of three parts: proportional (P), integral (I), and differential (D). Through real-time monitoring and adjustment, it ensures the system's precise control of the threshold voltage. Determines the response speed of the adaptive PID controller to the current deviation, the proportional coefficient The larger the value, the faster the system responds to the deviation signal, but a too large proportional coefficient May cause system overshoot; integral coefficient Used to eliminate steady-state errors, by integrating the deviation signal, so that the system can reach the target value after a long period of operation; differential coefficient The changing trend of the deviation signal can be predicted, the control quantity can be adjusted in advance, overshoot can be suppressed, and system stability can be enhanced.

[0054] It should be noted that the convolutional neural network includes an input layer, a convolution layer, a pooling layer, and a fully connected layer. The input layer receives the pre-processed historical threshold voltage and deviation signals as well as environmental parameters (such as temperature and stress). The data dimension is N×M, where N is the length of the time series and M is the number of features. The convolution layer contains at least 3 two-dimensional convolution layers. The convolution kernel size of each layer is 3×3 or 5×5, and the number of channels is 32 / 64 / 128 respectively, which are extracted through convolution operations. The pooling layer sets a maximum pooling layer between adjacent convolution layers. The pooling window size is 2×2 and the step size is 2, which is used to reduce dimensionality and reduce the amount of calculation. The fully connected layer contains 2 fully connected layers, and the number of neurons is 256 and 3 respectively (corresponding to the proportional coefficient , integral coefficient , differential coefficient ).

[0055] Furthermore, the control module is provided with a first current change rate threshold and the second current change rate threshold , and the first current change rate threshold Greater than the second current change threshold ; The control module is based on the current change rate and the first current change rate threshold and the second current change rate threshold The relationship between the current and the control signal is dynamically adjusted; when the current change rate Greater than the first current change rate threshold When the control module generates a control signal based on the deviation signal and the current change rate, the weight of the current change rate is increased; when the current change rate Less than the second current change rate threshold , when the control module generates a control signal according to the deviation signal and the current change rate, the weight of the current change rate is reduced.

[0056] In this embodiment, the control module will be described in detail. A first current change rate threshold is preset in the control module. and the second current change rate threshold , and the first current change rate threshold Greater than the second current change rate threshold , the control module is based on the current change rate and the first current change rate threshold and the second current change rate threshold The secondary feedback loop dynamically adjusts the control signal by monitoring the current change rate of the field effect transistor in real time. , and at the preset first current change rate threshold and the second current change rate threshold Comparison can achieve dynamic adjustment of the control signal. More specifically, when the current change rate Greater than the first current change rate threshold , which means that the circuit is in a highly dynamic change condition. For example, when the load in the power supply circuit increases instantaneously, the secondary feedback loop will increase its response weight to the deviation signal to ensure a fast response of the system. For example, the original main feedback loop and the secondary feedback loop may affect the control signal in a ratio of 7:3. In this condition, the ratio may be adjusted to 6:4, so that the control module focuses more on adjusting the gate voltage according to the current change trend and adjusting the threshold voltage in advance to avoid excessive fluctuations in the threshold voltage due to sudden current changes, which may affect the performance of the circuit. When the current change rate Less than the second current change rate threshold , indicating that the circuit runs smoothly, the secondary feedback loop reduces its response weight to the deviation signal, and the deviation signal based on the threshold voltage of the main feedback loop is the main one, ensuring the stability of the control while reducing unnecessary computing resource consumption. In the transition interval, the system will use algorithms including but not limited to linear interpolation or fuzzy control to smoothly adjust the weight ratio to prevent sudden changes in the control signal.

[0057] Furthermore, the control module further includes a reinforcement learning unit, which dynamically adjusts the first current change rate threshold value through a reward mechanism according to the control signal. and the second current change rate threshold .

[0058] In this embodiment, the control module will be described in detail again. The control module includes a reinforcement learning unit. The reinforcement learning unit dynamically adjusts the first current change rate threshold according to the reward mechanism by monitoring the effect of the control signal in real time. and the second current change rate threshold For example, if the system maintains a stable threshold voltage within a certain fluctuation range over a period of time and responds quickly and accurately to current changes, a positive reward will be given. Conversely, if problems such as severe threshold voltage overshoot or response delays occur, a negative reward will be given. By continuously accumulating reward values, the reinforcement learning unit can autonomously analyze whether the current threshold setting is suitable for the actual circuit operating conditions. Based on the reward value, the reinforcement learning unit dynamically fine-tunes the threshold, optimizes the control strategy, and improves the system's adaptability.

[0059] Furthermore, the control module also includes a signal processing unit and a drive unit; wherein the signal processing unit adopts a digital signal processor, and the signal processing unit is connected to the main feedback loop and the auxiliary feedback loop respectively to receive the deviation signal and the current change rate, and generate a preliminary control signal according to a preset algorithm. The algorithm calculation formula is: .in, Represented as the preliminary control signal, 、 、 They are respectively expressed as the proportional coefficient, integral coefficient and differential coefficient of the PID algorithm in the signal processing unit, Represented as a deviation signal, Expressed as the rate of change of the deviation signal, Expressed as the feedback coefficient of the secondary feedback loop, Expressed as the temperature compensation coefficient, It is expressed as the difference between the current temperature and the reference temperature; the driving unit is used to convert the preliminary control signal into a control signal capable of driving the gate of the field effect transistor.

[0060] In this embodiment, the control module will be described in detail again. The control module includes a signal processing unit and a drive unit. The signal processing unit uses a digital signal processor and is connected to the main feedback loop and the auxiliary feedback loop respectively to receive the deviation signal and the current change rate in real time, thereby generating a preliminary control signal according to a preset algorithm. The preset calculation algorithm is: .in, Represented as the preliminary control signal, 、 、 They are respectively expressed as the proportional coefficient, integral coefficient and differential coefficient of the PID algorithm in the signal processing unit, is expressed as the deviation signal, is expressed as the rate of change of the deviation signal, Expressed as the feedback coefficient of the secondary feedback loop, Expressed as the temperature compensation coefficient, It is expressed as the difference between the current temperature and the reference temperature; the driving unit is used to convert the preliminary control signal generated by the signal processing unit into a control signal capable of driving the gate of the field effect transistor.

[0061] Furthermore, it also includes a temperature compensation module and a stress compensation module; wherein the temperature compensation module is preset with a temperature threshold voltage compensation curve, and the stress compensation module is preset with a stress threshold compensation model; the temperature compensation module is connected to the field effect transistor, and is used to obtain the operating temperature of the field effect transistor and correct the set value according to the operating temperature and the temperature threshold voltage compensation curve; and / or, the stress compensation module is connected to the field effect transistor, and is used to obtain the mechanical stress on the field effect transistor package and correct the set value according to the mechanical stress and the stress threshold compensation model; the temperature threshold voltage compensation curve is established by the following formula: .in, Indicates the set value of the threshold voltage after correction, Expressed as the uncorrected threshold voltage setting, Expressed as the temperature coefficient, Indicates the operating temperature obtained by the temperature compensation module, Expressed as the reference temperature; the stress threshold compensation model is established by the following formula: .in, It is expressed as the set value of the threshold voltage after considering stress compensation, Expressed as stress coefficient, The mechanical stress values ​​are expressed as obtained.

[0062] In this embodiment, a field-effect transistor threshold voltage control system is described in detail. The system also includes a temperature compensation module and a stress compensation module. The temperature compensation module is pre-set with a temperature threshold voltage compensation curve, and the stress compensation module is pre-set with a stress threshold compensation model. The temperature compensation module is connected to the field-effect transistor to obtain the operating temperature of the field-effect transistor and to modify the set value based on the operating temperature and the temperature threshold voltage compensation curve. The stress compensation module is connected to the field-effect transistor to obtain the mechanical stress on the field-effect transistor package and to modify the set value based on the mechanical stress and the stress threshold compensation model.

[0063] For example, in some embodiments, a high-precision temperature chamber (such as ESPEC SH-241, with a temperature control accuracy of ±0.1°C and a temperature range of -70°C to 180°C) is used to place the field effect transistor on a constant temperature test board inside the temperature chamber to ensure uniform device temperature. A Keithley 2612B source meter is used to provide a stable test bias voltage for the field effect transistor, and a Keysight B1500A semiconductor parameter analyzer is used to collect the threshold voltage in real time with a sampling accuracy of 0.1mV. The temperature is lowered by 10°C, gradually increasing from -50°C to 120°C, and each temperature point is maintained for 30 minutes until the device reaches thermal equilibrium. At each temperature point, the gate-source voltage and drain-source voltage are kept constant, and the threshold voltage is collected every 5 minutes, with 6 sets of data obtained at each temperature point. The 6 sets of threshold voltage data for each temperature point are averaged to obtain the threshold voltage at that temperature. The least squares method is used to fit the temperature T and the threshold voltage to construct a polynomial function. , usually a second-order polynomial (n=2) can meet the temperature characteristics and fitting requirements of the field effect transistor, thereby obtaining the temperature threshold voltage compensation curve.

[0064] Perform verification experiments at untested temperature points (e.g., -30°C, 125°C), collect the actual threshold voltage, and compare it with the compensation curve's predicted value. If the error exceeds the set threshold (e.g., 50mV), readjust the fitting parameters or increase the density of temperature test points until the compensation curve meets the required accuracy.

[0065] In this embodiment, the threshold voltage control system of the field effect transistor further includes a temperature compensation module and a stress compensation module to correct the influence of environmental factors on the threshold voltage of the field effect transistor.

[0066] In practical applications, the operating environment of field-effect transistors is complex and changeable, and temperature and stress are important factors affecting the threshold voltage. The temperature compensation module includes, but is not limited to, real-time acquisition of the field-effect transistor's operating temperature through a temperature sensor. For example, in an automotive engine control module, the ambient temperature may quickly rise from room temperature to over 100°C while the engine is running. At this time, the temperature compensation module can quickly detect this temperature change and adjust the threshold voltage setting. The threshold voltage of semiconductor devices decreases as the temperature rises. After adjusting the set value through the temperature compensation module, the threshold voltage of the field-effect transistor remains within the ideal operating range at different temperatures.

[0067] The stress compensation module is responsible for monitoring the mechanical stress experienced by the field-effect transistor package. For example, in aerospace equipment, devices are subject to significant vibration and impact stress during launch, and may also experience stress due to thermal expansion and contraction during daily operation. The stress compensation module includes, but is not limited to, real-time acquisition of mechanical stress via a stress sensor. If a stress value of 5 MPa is detected, the stress compensation module will modify the set value based on the stress threshold compensation model. The temperature compensation module and the stress compensation module work in conjunction with the main feedback loop and the secondary feedback loop. When the actual value of the threshold voltage collected by the main feedback loop deviates from the set value after compensation by the temperature compensation module and the stress compensation module, the control module adjusts the gate voltage based on the deviation signal and the current change rate to achieve more precise control.

[0068] In this embodiment, the establishment of the temperature threshold voltage compensation curve will be described in detail, and the establishment is based on the formula: Establish. Among them, Indicates the set value of the threshold voltage after correction, Expressed as the uncorrected threshold voltage setting, It is expressed as a temperature coefficient, which can be obtained by conducting a large number of experimental tests on field-effect transistors at different temperatures. Field-effect transistors of different materials and processes have different temperature coefficients. For example, the temperature coefficient of silicon-based MOSFET is generally around -2mV / ℃. Indicates the operating temperature obtained by the temperature compensation module, Indicated as the reference temperature.

[0069] It should be noted that the temperature coefficient This can be achieved by placing the field effect transistor in a programmable high and low temperature test chamber with a temperature control accuracy of ±0.5°C and humidity maintained at 20%-80% RH to ensure a stable environment; at the reference temperature =25℃, apply a standard operating voltage to the field effect transistor through a high-precision voltage source (accuracy ±0.1mV), use a semiconductor parameter analyzer (such as Keysight B1500A) to collect the threshold voltage, repeat the measurement 10 times and take the average value; at intervals of 10℃, gradually increase the temperature from -55℃ to 150℃, and maintain each temperature point for 30 minutes to allow the device to reach thermal equilibrium. During this period, collect the threshold voltage every 5 minutes, and obtain a total of 60 sets of data; use the least squares method to perform a linear fit on the relationship between temperature T and threshold voltage, and the result is the temperature coefficient ; Carry out verification experiments at non-test temperature points (such as -20℃, 120℃). If the error between the measured value and the fitted value exceeds ±3%, readjust the test parameters or add more samples.

[0070] Stress coefficient Obtained through the following steps: Using a micro-electromechanical stress loading platform (accuracy ±1MPa), a mechanical stress of 0-150MPa is applied to the field effect transistor package by the four-point bending method or the thin film deposition stress method; during the stress loading process, the device operating current is kept constant (e.g., 100mA) and the stress value is collected synchronously S and threshold voltage, acquisition frequency 1Hz; stress analysis using polynomial regression S and threshold voltage offset relationship, build a model （ Higher-order terms can be ignored, simplified to a linear model), take the first-order coefficient as the stress coefficient; apply stress in the axial, radial and shear directions respectively, and verify If the difference exceeds 5%, a three-dimensional stress compensation model is constructed using tensor analysis.

[0071] In this embodiment, the stress threshold compensation model is described in detail. The stress compensation model is established by the following formula: .in, It is expressed as the set value of the threshold voltage after considering stress compensation, Expressed as stress coefficient, Represents the value of the mechanical stress obtained. For example, in some industrial automation equipment, the mechanical stress of the field effect transistor is known to be -0.5mV / MPa. When the stress sensor detects S =8MPa, it can be calculated that the threshold voltage decreases by 4mV due to stress, so the set value can be adjusted accordingly.

[0072] Furthermore, the source of the field effect transistor is grounded, the drain is connected to the load circuit, and the gate is connected to the output terminal of the control module; a variable capacitor is connected in series between the gate of the field effect transistor and the output terminal of the control module, and the variable capacitor is used to adjust the voltage change rate of the gate of the field effect transistor. The capacitance value of the variable capacitor is dynamically adjusted according to the current change rate. The adjustment formula is: .in, C It is expressed as the capacitance value of the variable capacitor after adjustment, Represents the initial capacitance value of the variable capacitor, Expressed as the adjustment coefficient.

[0073] In this embodiment, a field-effect transistor is described in detail. The source of the field-effect transistor is grounded, the drain is connected to a load circuit, and the gate is connected to the output of a control module. A variable capacitor is connected in series between the gate of the field-effect transistor and the output of the control module. The variable capacitor is used to adjust the rate of change of the voltage at the gate of the field-effect transistor. The capacitance of the variable capacitor is dynamically adjusted according to the rate of change of the current. The variable capacitor is not a fixed value but can be dynamically adjusted based on the actual operating state of the circuit, particularly the rate of change of the current.

[0074] The working principle is that the role of the variable capacitor is to adjust the rate of change of the gate voltage. The capacitor has the characteristic of hindering voltage mutations. By changing the value of the capacitance, the speed at which the gate voltage rises or falls can be controlled. In this embodiment, the capacitance value is adjusted according to the formula: .in, C It is expressed as the capacitance value of the variable capacitor after adjustment, Represents the initial capacitance value of the variable capacitor, Expressed as the regulation coefficient. For example, in a high-frequency switching power supply circuit, when the load increases instantaneously, the current change rate Rapidly increase, assuming ， =2pF / (A / s) , the circuit change rate reaches 5A / s, and the adjusted capacitance value can be calculated according to the formula . When the capacitance value increases, the rate of change of the gate voltage will slow down accordingly, avoiding excessive switching losses of the field effect transistor due to voltage mutations, generating electromagnetic interference, or overshooting of the threshold voltage due to rapid voltage changes, which affects the stable operation of the circuit. On the contrary, when the current change rate is small, the variable capacitance value decreases, and the gate voltage can quickly respond to changes in the control signal, ensuring that the system can achieve efficient and stable control under different working conditions. Furthermore, the main feedback loop also includes a voltage sampling subcircuit and an analog-to-digital conversion subcircuit; wherein, the voltage sampling subcircuit is used to collect the actual value of the threshold voltage of the field effect transistor, and the analog-to-digital conversion subcircuit is used to convert the actual value of the threshold voltage into a digital signal for processing by the control module; the voltage sampling subcircuit adopts a differential sampling method and is provided with an anti-aliasing filter, and the cutoff frequency of the anti-aliasing filter is adaptively adjusted according to the operating frequency of the field effect transistor.

[0075] In this embodiment, the main feedback loop will be described in detail again. The main feedback loop also includes a voltage sampling subcircuit and an analog-to-digital conversion subcircuit. The voltage sampling subcircuit is used to collect the actual value of the threshold voltage of the field-effect transistor, and the analog-to-digital conversion subcircuit is used to convert the actual threshold voltage value into a digital signal (e.g., a 12-bit binary value) for processing by the control module. The voltage sampling subcircuit uses a differential sampling method, simultaneously sampling the gate and source voltages via two signal lines (V+ and V-), calculating the difference using a differential amplifier, and is equipped with an anti-aliasing filter. The cutoff frequency of the anti-aliasing filter is adaptively adjusted based on the operating frequency of the field-effect transistor. The anti-aliasing filter is used to filter out high-frequency noise above the Nyquist frequency (1 / 2 the sampling rate) to prevent distortion caused by spectral aliasing.

[0076] Furthermore, the secondary feedback loop also includes a current sampling subcircuit and a differential operation subcircuit; wherein, the current sampling subcircuit is used to collect the current of the field effect transistor, and the differential operation subcircuit is used to calculate the rate of change of the current; the current sampling subcircuit adopts a Hall current sensor and is provided with an error compensation subcircuit. The error compensation subcircuit calculates the error according to the temperature and the offset characteristics of the Hall element through the following formula: Correct the collected current value; Expressed as the corrected current value, Expressed as the measured current value, Expressed as the temperature error compensation coefficient, Expressed as the offset error compensation coefficient, O Expressed as the offset of the Hall element.

[0077] In this embodiment, the sub-feedback loop will be explained in detail. The sub-feedback loop includes a current acquisition sub-circuit and a differential operation sub-circuit.

[0078] The function of the current acquisition subcircuit is to collect the circuit of the field effect transistor. The current acquisition subcircuit includes but is not limited to the use of Hall current sensor as the core acquisition element. The Hall current sensor is based on the Hall effect and can achieve non-contact measurement of current. It has the advantages of fast response speed and good linearity. At the same time, in order to solve the temperature drift and inherent offset problems of the Hall current sensor, an error compensation subcircuit is added to the circuit. Through a specific calculation formula Correct the collected current value to ensure the accuracy of the collected data. Expressed as the corrected current value, Expressed as the measured current value, Expressed as the temperature error compensation coefficient, Expressed as the offset error compensation coefficient, O Expressed as the offset of the Hall element.

[0079] The differential operation subcircuit is responsible for processing the current signal collected by the current sampling circuit, calculating the rate of change of the current, and providing the control unit with key data reflecting the dynamic change trend of the circuit, so that the system can quickly respond to sudden changes in the current.

[0080] A second purpose of this embodiment is to provide a threshold voltage control device for a field effect transistor, wherein the control device is provided with at least one control system as described above.

[0081] This embodiment further provides a threshold voltage control device for a field effect transistor, which is provided with a control system as provided in the above embodiment.

[0082] It should be noted that the embodiments of the present invention have better practicability and do not impose any form of limitation on the present invention. Any technician familiar with the field may use the technical content disclosed above to change or modify it into an equivalent effective embodiment. However, any modification or equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A threshold voltage control system for a field effect transistor, characterized in that: It includes a main feedback loop, a sub-feedback loop, a field effect transistor and a control module; wherein, The main feedback loop is connected to the field effect transistor and the control module, and is used to obtain an actual value of a threshold voltage of the field effect transistor, compare the actual value of the threshold voltage with a set value to obtain a deviation signal, and send the deviation signal to the control module; The main feedback loop also includes a voltage sampling subcircuit and an analog-to-digital conversion subcircuit; wherein, The voltage sampling subcircuit is used to collect the actual value of the threshold voltage of the field effect transistor, and the analog-to-digital conversion subcircuit is used to convert the actual value of the threshold voltage into a digital signal for processing by the control module; The voltage sampling subcircuit adopts a differential sampling method and is provided with an anti-aliasing filter, the cutoff frequency of the anti-aliasing filter being adaptively adjusted according to the operating frequency of the field effect transistor; The secondary feedback loop is connected to the field effect transistor and the control module, and the secondary feedback loop is used to collect the current change rate of the field effect transistor and send the current change rate to the control module; The secondary feedback loop further includes a current sampling subcircuit and a differential operation subcircuit; wherein, The current sampling subcircuit is used to collect the current of the field effect transistor, and the differential operation subcircuit is used to calculate the rate of change of the current; The current sampling subcircuit uses a Hall current sensor and is provided with an error compensation subcircuit. The error compensation subcircuit calculates the error according to the temperature and the offset characteristics of the Hall element by the following formula: Correct the collected current value; in, Expressed as the corrected current value, Expressed as the measured current value, Expressed as the temperature error compensation coefficient, Expressed as the offset error compensation coefficient, Expressed as the offset of the Hall element, Expressed as the difference between the current temperature and the reference temperature; The control module is configured to generate a control signal according to the deviation signal and the current change rate, and adjust the gate voltage of the field effect transistor according to the control signal to control the threshold voltage of the field effect transistor.

2. The field effect transistor threshold voltage control system according to claim 1, characterized in that: The main feedback loop includes an adaptive PID controller; The adaptive PID controller uses a deep learning algorithm and dynamically adjusts the proportional coefficient based on the historical threshold voltage and the deviation signal. , integral coefficient , differential coefficient ; The deep learning algorithm uses a convolutional neural network to pre-process the historical threshold voltage and the deviation signal as input and output the dynamically adjusted proportional coefficient. , integral coefficient differential coefficient .

3. The field effect transistor threshold voltage control system according to claim 1, characterized in that: The control module is provided with a first current change rate threshold and the second current change rate threshold , and the first current change rate threshold Greater than the second current change rate threshold ; The control module is configured to control the current change rate according to the current change rate. The first current change rate threshold and the second current change rate threshold dynamically adjusting the control signal; When the current change rate Greater than the first current change rate threshold , when the control module generates the control signal according to the deviation signal and the current change rate, increasing the weight of the current change rate; When the current change rate Less than the second current change rate threshold When the control module generates the control signal according to the deviation signal and the current change rate, the weight of the current change rate is reduced.

4. The field effect transistor threshold voltage control system according to claim 3, characterized in that: The control module further includes a reinforcement learning unit, which dynamically adjusts the first current change rate threshold value through a reward mechanism according to the control signal. and the second current change rate threshold .

5. The field effect transistor threshold voltage control system according to claim 1, wherein: The control module further includes a signal processing unit and a driving unit; wherein, The signal processing unit adopts a digital signal processor, and is connected to the main feedback loop and the auxiliary feedback loop respectively to receive the deviation signal and the current change rate, and generate a preliminary control signal according to a preset algorithm. The algorithm calculation formula is: , in, Denoted as the preliminary control signal, are respectively represented as the proportional coefficient, integral coefficient and differential coefficient of the PID algorithm in the signal processing unit, e is represented as the deviation signal, Expressed as the rate of change of the deviation signal, Expressed as the feedback coefficient of the secondary feedback loop, Expressed as the temperature compensation coefficient, Expressed as the difference between the current temperature and the reference temperature; The driving unit is configured to convert the preliminary control signal into the control signal capable of driving the gate of the field effect transistor.

6. The field effect transistor threshold voltage control system according to claim 1, characterized in that: It also includes a temperature compensation module and a stress compensation module; Wherein, the temperature compensation module is preset with a temperature threshold voltage compensation curve, and the stress compensation module is preset with a stress threshold compensation model; The temperature compensation module is connected to the field effect transistor and is used to obtain the operating temperature of the field effect transistor and to modify the set value according to the operating temperature and the temperature threshold voltage compensation curve; and / or the stress compensation module is connected to the field effect transistor and is used to obtain the mechanical stress on the field effect transistor package and to modify the set value according to the mechanical stress and the stress threshold compensation model; The temperature threshold voltage compensation curve is established by the following formula: ， in, is represented by the set value of the threshold voltage after correction, The threshold voltage setting value is expressed as uncorrected, Expressed as the temperature coefficient, represents the operating temperature obtained by the temperature compensation module, Expressed as reference temperature; The stress threshold compensation model is established by the following formula: , in, It represents the set value of the threshold voltage after considering stress compensation, Expressed as stress coefficient, The mechanical stress value obtained is represented as .

7. The field effect transistor threshold voltage control system according to claim 3, characterized in that: The source of the field effect transistor is grounded, the drain is connected to the load circuit, and the gate is connected to the output end of the control module; A variable capacitor is connected in series between the gate of the field effect transistor and the output terminal of the control module. The variable capacitor is used to adjust the voltage change rate of the gate of the field effect transistor. The capacitance value of the variable capacitor is dynamically adjusted according to the current change rate. The adjustment formula is: , in, Represents the capacitance value of the variable capacitor after adjustment, is represented as the initial capacitance value of the variable capacitor, Expressed as the adjustment coefficient.

8. A threshold voltage control device for a field effect transistor, characterized in that: The control device is provided with at least one control system according to any one of claims 1 to 7.

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