A high-precision charging management and airflow sensing integrated method

Abstract

The application relates to the technical field of charge management, in particular to a high-precision charge management and airflow sensing integrated method, which comprises the following steps: reading temperature compensation parameter groups, airflow front end compensation parameter groups, charge access judgment parameter groups and output linkage adjustment parameter groups in pre-written in-chip configuration data; taking an energy storage unit end voltage as a power supply to generate a shared reference voltage and input the shared reference voltage into a charge comparison circuit and a capacitor frequency conversion circuit; collecting an external charge voltage and judging an external charge access state; under the external charge access state, identifying a dead zone window based on a power switch tube PWM driving signal, triggering airflow sensing capacitor segmented charge and discharge conversion in the dead zone window, and obtaining a pulse signal sequence; determining an airflow state level based on the pulse signal sequence, and combining a voltage state signal to link and adjust a load output duty ratio and a charge current limit value.

Description

Technical Field

[0001] This invention relates to the field of charging management technology, specifically to a high-precision charging management and airflow sensing integration method. Background Technology

[0002] Charging management and airflow sensing integrated circuits are commonly used in electronic devices that need to simultaneously charge energy storage units, control load output, and detect airflow conditions. These circuits typically include modules such as a charging comparator circuit, a power switch driver circuit, an airflow sensing front-end, a capacitor frequency conversion circuit, and a global state machine logic. During external charging and load output, the energy storage unit's terminal voltage, charging current, and on-chip temperature change with the operating state. The PWM drive of the power switch introduces switching noise, reference ripple, and sampling environment disturbances, which may affect the on-chip power supply, reference voltage, and the sampling stability of the sensing front-end.

[0003] Current solutions typically implement charging management and airflow detection functions separately, and can meet basic control requirements through independent references, filtering, and status judgment. However, with the miniaturization of electronic devices and the increase in on-chip integration, when the charging management circuit and the airflow sensing front end work together in the same chip or the same control system, the requirements for reference voltage consistency, sampling timing coordination, and output control linkage are further increasing.

[0004] In scenarios where airflow sensing capacitors are used for detection at the front end of the airflow sensor, the capacitor charging and discharging conversion process is related to the on-chip temperature state, reference voltage stability, and power switch timing. If charging comparison, capacitor frequency conversion, and load output regulation are executed independently, the reference ripple introduced by the PWM drive and the sampling environment disturbances may affect the counting stability of the airflow sensing capacitor conversion time, and make charging current limiting and load output regulation lack a unified state basis.

[0005] To address this, a high-precision charging management and airflow sensing integration method is proposed. Summary of the Invention

[0006] This invention aims to provide a high-precision charging management and airflow sensing integration method. It generates a shared reference voltage using the energy storage unit's terminal voltage as the power supply, and inputs this shared reference voltage into both the charging comparator circuit and the capacitor frequency conversion circuit. Under external charging access conditions, it identifies the dead zone window between the high-side transistor being off and the low-side transistor being on, and performs segmented sampling of the airflow sensing capacitor based on this dead zone window. Furthermore, it combines the airflow state level and voltage state signal as the basis for output adjustment, and performs linked adjustment of the load output duty cycle and charging current limit.

[0007] To achieve the above objectives, the present invention provides the following technical solution: A high-precision charging management and airflow sensing integration method includes: Read the on-chip configuration data, generate a shared reference voltage using the energy storage unit terminal voltage as the power supply, and input the shared reference voltage into the charging comparator circuit and the capacitor frequency conversion circuit respectively to obtain the voltage status signal of the charging comparator circuit. Temperature is collected by the on-chip temperature detection circuit, and temperature drift compensation is performed based on the temperature detection to obtain a temperature compensation signal. The oscillation circuit and threshold comparison circuit at the front end of the airflow sensor are then compensated based on the temperature compensation signal. Under the logic control of the global state machine, the external charging voltage is collected to determine the external charging access status. When the external charging access status is reached, the dead window between the high-side transistor being turned off and the low-side transistor being turned on is identified based on the PWM drive signal of the power switch. Within the continuous dead window, a sampling enable signal is output to trigger the capacitor frequency conversion circuit to perform segmented charging and discharging conversion on the airflow sensor capacitor based on the shared reference voltage and the airflow sensor front end, and accumulate the latched single-window sampling count value to obtain a pulse signal sequence. The airflow state level is determined by the pulse signal sequence. The output control parameters are adjusted in conjunction with the airflow level and voltage status signals.

[0008] Preferably, reading the on-chip configuration data includes: reading the temperature compensation parameter group, airflow front-end compensation parameter group, charging access judgment parameter group and output linkage adjustment parameter group pre-written into the on-chip configuration data.

[0009] Preferably, the step of generating a shared reference voltage and inputting the shared reference voltage into the charging comparator circuit and the capacitor frequency conversion circuit includes: stabilizing the voltage at the energy storage unit terminals to obtain the on-chip power supply voltage; driving the on-chip bandgap reference voltage network based on the on-chip power supply voltage to output the original reference voltage; chopping and stabilizing the original reference voltage to obtain the shared reference voltage; inputting the shared reference voltage into the charging comparator circuit and inputting the energy storage unit terminal voltage into the charging comparator circuit after voltage division and filtering, and obtaining the voltage status signal after hysteresis comparison; and inputting the shared reference voltage into the capacitor frequency conversion circuit as the reference input quantity for the charging and discharging conversion of the airflow sensing capacitor.

[0010] Preferably, the compensation of the oscillation circuit and threshold comparison circuit of the airflow sensor front end based on the temperature compensation signal includes: reading the temperature reference quantity and the segmented temperature coefficient from the temperature compensation parameter group; acquiring the temperature detection quantity through the on-chip temperature detection circuit and filtering the temperature detection quantity to obtain a stable temperature detection quantity; determining the temperature offset quantity based on the difference between the stable temperature detection quantity and the temperature reference quantity; performing gain processing on the temperature offset quantity according to the segmented temperature coefficient of the interval in which the temperature offset quantity is located to obtain a temperature compensation signal; reading the oscillation compensation coefficient, oscillation control reference quantity, threshold compensation coefficient, and comparison threshold reference quantity from the airflow front end compensation parameter group; performing gain processing on the temperature compensation signal according to the oscillation compensation coefficient and superimposing the oscillation control reference quantity to obtain an oscillation control quantity; inputting the oscillation control quantity into the oscillation circuit of the airflow sensor front end to compensate for the charging and discharging conversion process of the airflow sensor capacitor; performing gain processing on the temperature compensation signal according to the threshold compensation coefficient and superimposing the comparison threshold reference quantity to obtain a comparison threshold; inputting the comparison threshold into the threshold comparison circuit of the airflow sensor front end to compensate for the charging and discharging conversion determination process of the airflow sensor capacitor.

[0011] Preferably, the step of acquiring the external charging voltage and determining the external charging access status based on the external charging voltage includes: reading the external charging access threshold and the external charging disconnection threshold from the charging access judgment parameter group; acquiring the external charging voltage under the logic control of the global state machine to obtain the external charging voltage sample quantity; filtering the external charging voltage sample quantity to obtain a stable external charging voltage quantity; performing a hysteresis comparison between the stable external charging voltage quantity and the external charging access threshold and the external charging disconnection threshold; setting the external charging access status when the stable external charging voltage quantity is greater than or equal to the external charging access threshold; and resetting the external charging access status when the stable external charging voltage quantity is less than the external charging disconnection threshold.

[0012] Preferably, the identification of the dead zone window between the high-side transistor being turned off and the low-side transistor being turned on includes: when the external charging access state is set, causing the global state machine logic to enter the PWM drive signal monitoring state; in the PWM drive signal monitoring state, acquiring the high-side PWM drive signal and the low-side PWM drive signal; performing effective-to-invalid level transition detection on the high-side PWM drive signal to obtain a high-side turn-off edge flag; performing invalid-to-effective level transition detection on the low-side PWM drive signal to obtain a low-side turn-on edge flag; using the high-side turn-off edge flag as the start flag of the dead zone window and the low-side turn-on edge flag as the end flag of the dead zone window; and forming the dead zone window based on the start flag and the end flag.

[0013] Preferably, the obtained pulse signal sequence includes: setting the sampling enable signal when the start flag of the dead window appears; triggering the capacitor frequency conversion circuit to charge and discharge the airflow sensing capacitor based on a shared reference voltage while the sampling enable signal is active; counting the conversion time of the airflow sensing capacitor to obtain a single-window counting result while the sampling enable signal is active; resetting the sampling enable signal when the end flag of the dead window appears, and latching the single-window sampling count value as a single-window sampling count value when the single-window counting result is not lower than the minimum counting threshold in the airflow front-end compensation parameter group, while maintaining the current conversion state of the airflow sensing capacitor; triggering the capacitor frequency conversion circuit to continue charging and discharging based on the current conversion state when the start flag of the next dead window appears; accumulating the single-window sampling count values ​​latched in consecutive dead windows according to the sampling order to obtain an accumulated sampling value; and performing threshold-triggered pulse generation processing on the accumulated sampling value to obtain a pulse signal sequence.

[0014] Preferably, the step of adjusting the output control parameters in a coordinated manner includes: reading the airflow reference count value and the airflow level determination coefficient from the output coordinated adjustment parameter group, wherein the airflow level determination coefficient includes the grading boundary of the airflow offset; performing edge counting on the pulse signal sequence to obtain the airflow detection count value; determining the airflow offset based on the difference between the airflow detection count value and the airflow reference count value; determining the airflow state level based on the comparison result between the airflow offset and the grading boundary; combining the airflow state level and the voltage state signal into a coordinated state index; locating the coordinated adjustment coefficient in the output coordinated adjustment parameter group according to the coordinated state index, and determining the output control parameter adjustment level according to the adjustment direction and adjustment amplitude level indicated by the coordinated adjustment coefficient; and updating the load output duty cycle and charging current limit in the output control parameters according to the output control parameter adjustment level.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. This invention reads the temperature compensation parameter group, airflow front-end compensation parameter group, charging access judgment parameter group, and output linkage adjustment parameter group from the on-chip configuration data, enabling temperature compensation, airflow front-end compensation, charging access judgment, and output linkage adjustment to be executed within the same controller based on corresponding parameters. At the same time, the temperature compensation amount participates in airflow front-end compensation, the charging access status participates in subsequent dead-zone window identification, and the airflow detection result and voltage status signal further participate in output linkage adjustment. Thus, parameter reading, signal compensation, status judgment, and output adjustment form a continuous processing link according to global state machine logic.

[0016] 2. This invention regulates the voltage at the energy storage unit terminals to drive an on-chip bandgap reference voltage network to generate a shared reference voltage. This shared reference voltage is then input to both the charging comparator circuit and the capacitor frequency conversion circuit. The charging comparator circuit outputs a voltage status signal based on the shared reference voltage, while the capacitor frequency conversion circuit performs charge / discharge conversion on the gas flow sensing capacitor based on the same shared reference voltage. This ensures that the charging voltage status judgment and gas flow sensing conversion processes are executed based on the same on-chip reference, reducing the impact of different reference sources on subsequent linkage adjustment results.

[0017] 3. After the external charging access state is set, this invention identifies the dead zone window between the high-side transistor being off and the low-side transistor being on, and triggers the segmented charging and discharging conversion of the airflow sensing capacitor within the dead zone window. The single-window sampling count values ​​obtained within the continuous dead zone windows are accumulated and pulse-shaped to form a pulse signal sequence, further obtaining the airflow detection count value and airflow state level. The global state machine logic combines the airflow state level with the voltage state signal to form a linkage state index, and updates the load output duty cycle and charging current limit accordingly, so that the airflow sampling timing, charging voltage state, and output control parameters form a linkage adjustment relationship executed according to the state index. Attached Figure Description

[0018] Figure 1 This is an overall flowchart of a high-precision charging management and airflow sensing integration method of the present invention; Figure 2 This is a flowchart illustrating the baseline and compensation process of the present invention. Figure 3 This is a flowchart of the dead zone sampling and linkage adjustment process of the present invention. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] Example 1: This invention proposes a high-precision charging management and airflow sensing integration method, the process of which is as follows: Figure 1 As shown, the shared reference voltage and temperature compensation process is as follows: Figure 2 As shown, the dead-zone window sampling and output linkage adjustment process is as follows: Figure 3 As shown, it specifically includes: Read the on-chip configuration data, generate a shared reference voltage using the energy storage unit terminal voltage as the power supply, and input the shared reference voltage into the charging comparator circuit and the capacitor frequency conversion circuit respectively to obtain the voltage status signal of the charging comparator circuit. Temperature is collected by the on-chip temperature detection circuit, and temperature drift compensation is performed based on the temperature detection to obtain a temperature compensation signal. The oscillation circuit and threshold comparison circuit at the front end of the airflow sensor are then compensated based on the temperature compensation signal. Under the logic control of the global state machine, the external charging voltage is collected to determine the external charging access status. When the external charging access status is reached, the dead window between the high-side transistor being turned off and the low-side transistor being turned on is identified based on the PWM drive signal of the power switch. Within the continuous dead window, a sampling enable signal is output to trigger the capacitor frequency conversion circuit to perform segmented charging and discharging conversion on the airflow sensor capacitor based on the shared reference voltage and the airflow sensor front end, and accumulate the latched single-window sampling count value to obtain a pulse signal sequence. The airflow state level is determined by the pulse signal sequence. The output control parameters are adjusted in conjunction with the airflow level and voltage status signals.

[0021] In this invention, the airflow sensing capacitor is a capacitive detection unit in the airflow sensing front end. The airflow sensing front end includes an airflow channel, an elastic sensitive part, and a fixed electrode. An equivalent capacitance related to the airflow state is formed between the elastic sensitive part and the fixed electrode. When the airflow state in the airflow channel changes, the airflow acts on the elastic sensitive part, causing the position of the elastic sensitive part relative to the fixed electrode to change, thereby changing the equivalent capacitance parameter of the airflow sensing capacitor. The capacitor frequency conversion circuit changes the charging and discharging conversion process of the airflow sensing capacitor according to the change of the equivalent capacitance parameter, and obtains a pulse signal sequence corresponding to the airflow state through counting and pulse shaping. The airflow reference count value and the airflow level determination coefficient can be obtained through the airflow front end calibration process to establish the correspondence between the airflow sensing capacitor conversion result and the airflow state level. The increase or decrease relationship between the equivalent capacitance parameter and the airflow detection count value is determined by the airflow front end calibration process; when the airflow increases in the actual sensing structure and the corresponding airflow detection count value increases, the controller determines the airflow state level according to the positive relationship; when the airflow increases in the actual sensing structure and the corresponding airflow detection count value decreases, the controller determines the airflow state level according to the reverse relationship.

[0022] The capacitor-frequency conversion circuit charges and discharges the airflow sensing capacitor under the action of a shared reference voltage, and a threshold comparison circuit determines whether the airflow sensing capacitor conversion node has reached the comparison threshold. When the equivalent capacitance parameter of the airflow sensing capacitor changes, the time required for it to complete the charge-discharge conversion under the same reference input and the same threshold judgment conditions changes accordingly. The counting logic counts this conversion time to form a single-window sampling count value. Therefore, changes in airflow state are transmitted sequentially through changes in the position of the elastic sensing part, changes in the equivalent capacitance parameter, changes in the charge-discharge conversion time, and changes in the single-window sampling count value, and are further reflected in changes in the cumulative sample value and pulse signal sequence.

[0023] Furthermore, reading the on-chip configuration data includes reading the temperature compensation parameter group, airflow front-end compensation parameter group, charging access judgment parameter group, and output linkage adjustment parameter group that are pre-written into the on-chip configuration data.

[0024] Specifically, the temperature compensation parameter set is written into the on-chip configuration data by the temperature calibration process. This parameter set includes a temperature reference value, temperature offset interval boundary values, piecewise temperature coefficients, and smoothing weights for subsequent temperature compensation calculations. The temperature calibration process determines the temperature offset interval boundary values, piecewise temperature coefficients, and smoothing weights based on the temperature detection value output by the on-chip temperature detection circuit, the temperature reference value, and the conversion results of the airflow sensor front-end under different temperature conditions. After reading the temperature compensation parameter set, the controller determines the temperature offset based on the temperature sampling code value output by the on-chip temperature sampling channel and the temperature reference value during operation. It then compares the temperature offset with the temperature offset interval boundary values ​​to determine the temperature offset interval in which the temperature offset is located, and generates the temperature compensation value by combining it with the corresponding piecewise temperature coefficients. The smoothing weights are used for the first-order recursive smoothing of the temperature detection value.

[0025] The airflow front-end compensation parameter set is written into the on-chip configuration data by the airflow front-end calibration process. This parameter set includes oscillation compensation coefficients, oscillation control reference values, threshold compensation coefficients, comparison threshold reference values, and minimum counting thresholds for subsequent airflow front-end compensation calls, as well as oscillation control quantity working interval boundary values ​​and comparison threshold working interval boundary values ​​for boundary maintenance processing calls. The oscillation control quantity working interval boundary values ​​and comparison threshold working interval boundary values ​​are determined by the airflow front-end calibration process within the calibration temperature range. Specifically, at the upper and lower temperature points of the calibration temperature range, the upper and lower limits of the oscillation control quantity that enable the oscillation circuit to maintain normal oscillation and stable switching rhythm, and the upper and lower limits of the comparison threshold that enable the threshold comparison circuit to maintain normal comparison output are detected, and the detected upper and lower limits are written into the airflow front-end compensation parameter set. The oscillation control quantity working interval boundary values ​​have the same expression form as the oscillation control quantity, and the comparison threshold working interval boundary values ​​have the same expression form as the comparison threshold. The oscillation control quantity and comparison threshold are generated by the controller in the form of control quantities or control codes. When the airflow sensor front end requires analog input, it is converted into the corresponding circuit input quantity through the oscillation control configuration branch and the threshold configuration branch, respectively. The boundary values ​​of the working range of the oscillation control quantity and the working range of the comparison threshold in the airflow front end compensation parameter group are used to limit the control quantity range of the controller output to the corresponding configuration branch. After reading the airflow front end compensation parameter group, the controller generates the oscillation control quantity and the comparison threshold according to the temperature compensation signal during operation. The oscillation control quantity is used to input the oscillation circuit of the airflow sensor front end, and the comparison threshold is used to input the threshold comparison circuit of the airflow sensor front end.

[0026] The charging access judgment parameter set is written into the on-chip configuration data by the charging access status calibration process. This parameter set includes external charging access thresholds and external charging disconnection thresholds for subsequent charging access judgments. The charging access status calibration process determines the external charging access thresholds and external charging disconnection thresholds based on the correspondence between the external charging voltage sampling quantity and the external charging access status. After reading the charging access judgment parameter set, the controller inputs the external charging voltage sampling quantity into the hysteresis comparison logic during operation and compares the stable external charging voltage quantity with the external charging access threshold and external charging disconnection threshold. The status quantities output by the battery-side sampling channel and the access status detection circuit are used to assist in confirming the valid access judgment result and the valid disconnection judgment result, ensuring that interface access, interface release, and status maintenance can form a charging access status flag and be sent to the charging path control process and the airflow sampling timing control process.

[0027] The output linkage adjustment parameter set is written into the on-chip configuration data by the charging and airflow linkage calibration process. This parameter set includes an airflow reference count value, an airflow level determination coefficient, and a linkage adjustment coefficient for subsequent output linkage adjustments. The charging and airflow linkage calibration process determines the linkage adjustment coefficient corresponding to the linkage state index based on the correspondence between the airflow state level, voltage state signal, load output duty cycle, and charging current limit. After reading the output linkage adjustment parameter set, the controller generates a linkage state index based on the airflow state level and voltage state signal during operation, and locates the linkage adjustment coefficient based on the linkage state index, ensuring that the load output duty cycle and charging current limit are adjusted according to the synchronous update cycle of the global state machine logic.

[0028] Therefore, each parameter group in the on-chip configuration data participates in temperature compensation, airflow front-end compensation, charging access judgment and output linkage adjustment during operation, so that charging management and airflow sensing can be executed according to the corresponding parameters in the same controller.

[0029] Furthermore, the process of generating a shared reference voltage and inputting it into the charging comparator circuit and the capacitor frequency conversion circuit respectively includes stabilizing the voltage at the energy storage unit terminals, driving the on-chip bandgap reference voltage network based on the on-chip power supply voltage, chopping and stabilizing the original reference voltage, inputting the shared reference voltage into the charging comparator circuit, outputting the voltage state signal to the global state machine logic, and inputting the shared reference voltage into the capacitor frequency conversion circuit.

[0030] Specifically, when the voltage of the energy storage unit is regulated, the voltage of the energy storage unit is input to the on-chip voltage regulator unit by the sampling node of the energy storage unit. The on-chip voltage regulator unit suppresses the power supply ripple and load disturbance components in the voltage of the energy storage unit and outputs the on-chip power supply voltage to the low-noise power supply branch of the on-chip bandgap reference voltage network, charging comparator circuit and capacitor frequency conversion circuit.

[0031] Based on this, the acquisition of the raw reference voltage involves using the on-chip supply voltage as the power input to the on-chip bandgap reference voltage network. The on-chip bandgap reference voltage network combines junction voltage components with different temperature change directions and outputs the generated raw reference voltage to the reference stabilization processing branch.

[0032] Subsequently, the original reference voltage undergoes chopper stabilization processing. This involves a chopper clock signal generated by an on-chip oscillation clock branch and input to a chopper modulation switch. Driven by this chopper clock signal, the chopper stabilization branch modulates and suppresses the low-frequency offset component in the original reference voltage. The modulated reference voltage is then input to a low-pass filter network and a reference buffer circuit. The low-pass filter network attenuates the high-frequency ripple component generated by chopper modulation. The frequency configuration of the chopper clock signal is differentiated from the switching cycle of the PWM drive signal and the charging / discharging cycle of the airflow sensing capacitor, ensuring that there is no fixed sampling phase relationship between the chopper residual ripple, PWM switching disturbance, and the airflow sensing counting observation interval. The low-pass filter network retains the reference DC component and reduces the chopper residual ripple. The reference buffer circuit enhances the driving capability of the shared reference voltage for subsequent circuits, thereby forming a shared reference voltage. Before the shared reference voltage input charging comparator circuit and capacitor frequency conversion circuit, the global state machine logic performs corresponding judgments and conversions based on whether the on-chip power supply voltage and shared reference voltage can support the charging comparator circuit and capacitor frequency conversion circuit, and determines whether subsequent airflow sampling is allowed; when the on-chip power supply voltage or shared reference voltage cannot support the above judgments and conversions, the controller does not latch the single-window sampling count value, and keeps the load output duty cycle and charging current limit executed according to the current output control parameters.

[0033] The shared reference voltage input charging comparator circuit includes a shared reference voltage input to the reference terminal of the charging comparator circuit via a reference allocation node. The energy storage unit terminal voltage is input to the detection terminal of the charging comparator circuit after voltage division and filtering. The charging comparator circuit performs hysteresis comparison processing on the detection terminal voltage based on the shared reference voltage and outputs a voltage state signal indicating the voltage range of the energy storage unit terminal voltage.

[0034] Correspondingly, when the voltage status signal is output to the global state machine logic, the voltage status signal is input to the global state machine logic from the output of the charging comparator circuit. The global state machine logic generates the state input required for adjusting the charging current limit based on the voltage status signal, which helps to establish a linkage adjustment relationship between the charging path current limiting control and the voltage status at the energy storage unit.

[0035] On the other hand, the shared reference voltage input capacitor frequency conversion circuit includes a shared reference voltage input capacitor frequency conversion circuit via an isolation buffer branch. The isolation buffer branch includes a high input impedance buffer and a decoupling filter structure located on the buffer output side. The high input impedance buffer reduces the reverse coupling of the capacitor frequency conversion circuit and the charging comparator circuit's switching action to the shared reference node. The decoupling filter structure attenuates the residual ripple component before entering the capacitor frequency conversion circuit. The output response capability of the high input impedance buffer matches the sampling control cycle of the capacitor frequency conversion circuit. The decoupling filter structure is located on the reference input side of the capacitor frequency conversion circuit to reduce transient disturbances at the reference input terminal during the airflow sensing capacitor charging and discharging conversion process. The frequency response of the decoupling filter structure is configured according to the PWM switching frequency, the airflow sensing capacitor charging and discharging conversion cycle, and the hysteresis width of the charging comparator circuit, so that the high-frequency ripple component entering the reference input side of the capacitor frequency conversion circuit is attenuated, and the residual ripple of the shared reference node when the charging comparator circuit and the capacitor frequency conversion circuit operate simultaneously is within the allowable range for hysteresis comparison by the charging comparator circuit. When both the maximum charging current operating state and the continuous triggering state of the airflow sensor sampling exist simultaneously, a high input impedance buffer and decoupling filter structure are used to reduce the reverse coupling of the transient charging and discharging operation of the capacitor frequency conversion circuit to the shared reference node, so that the reference terminal of the charging comparator circuit is maintained within a stable range that allows for hysteresis comparison. The capacitor frequency conversion circuit uses the shared reference voltage processed by the isolation buffer branch as the reference input for the airflow sensor capacitor charging and discharging conversion.

[0036] Thus, the energy storage unit terminal voltage, on-chip supply voltage, original reference voltage, shared reference voltage, and voltage status signal form a continuous data and circuit transmission link. The shared reference voltage also serves as the reference input for the charging comparator circuit and the capacitor frequency conversion circuit, enabling the charging voltage status judgment and the airflow sensing capacitor charging and discharging conversion to be performed based on the same on-chip reference. The voltage status signal serves as the voltage-side input for subsequent output linkage regulation, participating in the adjustment of output control parameters together with the airflow state level.

[0037] Furthermore, the process of obtaining the temperature compensation signal and inputting it into the oscillation circuit and threshold comparison circuit at the front end of the airflow sensor includes reading the temperature reference quantity and temperature coefficient, acquiring and filtering to obtain a stable temperature detection quantity, determining the temperature offset, and generating the temperature compensation signal; it also includes reading the airflow front end compensation parameters, generating the oscillation control quantity and inputting it into the oscillation circuit, and generating the comparison threshold and inputting it into the threshold comparison circuit.

[0038] Specifically, when reading the temperature reference value and segmented temperature coefficient from the temperature compensation parameter group, the controller reads the temperature reference value, temperature offset interval boundary value, and segmented temperature coefficient written by the temperature calibration process from the temperature compensation parameter group in the on-chip configuration data. The temperature reference value is used to characterize the calibration reference position of the temperature detection quantity, the temperature offset interval boundary value is used to divide the offset range of the stable temperature detection quantity relative to the temperature reference value, and the segmented temperature coefficient is used to characterize the mapping relationship between the temperature offset amount within the corresponding temperature offset interval and the temperature correction amount of the airflow sensor front end. The temperature offset interval boundary value is determined by the temperature calibration process within the chip calibration temperature range; the temperature calibration process collects the temperature drift results of the airflow sensor front end at multiple calibration temperature points, and divides the temperature offset into multiple temperature offset intervals according to the changes in the temperature drift direction and amplitude between adjacent calibration temperature points. In one embodiment, the temperature offset interval includes at least a low temperature offset interval, a normal temperature offset interval, and a high temperature offset interval. The boundary value of each temperature offset interval and the corresponding segmented temperature coefficient are written together into the temperature compensation parameter group. During operation, the controller compares the current temperature offset with the boundary value of the temperature offset interval to determine the interval in which the current temperature offset is located, and calls the corresponding segmented temperature coefficient.

[0039] During temperature monitoring, the on-chip temperature detection circuit converts the temperature state of the chip's working area into a temperature measurement value. The controller filters this temperature measurement value using a first-order recursive smoothing method. The smoothing weight is a preset coefficient greater than 0 and less than 1, determined by the temperature calibration process based on the response speed of the on-chip temperature detection circuit and the sensitivity of the airflow sensor front-end to temperature changes, and written into the temperature compensation parameter group. The controller weights and combines the previous stable temperature measurement value and the current temperature measurement value according to this smoothing weight to obtain the current stable temperature measurement value; the weight corresponding to the previous stable temperature measurement value is complementary to the weight corresponding to the current temperature measurement value. If expressed symbolically, then: ; in, For the current stable temperature detection volume, This is the measurement value at the previous stable temperature. This is the current temperature measurement. For smoothing weights, and 0 < <1. , and Using the same expression, it can be either a temperature detection code value or a temperature value. When it is necessary to enhance the ability to suppress short-cycle jitter, the proportion of the previous stable temperature detection value in the weighted combination is increased; when it is necessary to improve the ability of the stable temperature detection value to follow the temperature change trend, the proportion of the current temperature detection value in the weighted combination is increased. This processing is used to suppress short-cycle jitter in the temperature detection value and to make the stable temperature detection value participate in subsequent calculations as a compensation input that changes slowly with the on-chip temperature.

[0040] Subsequently, the controller inputs the stable temperature detection value and the temperature reference value into the difference calculation unit, and the difference calculation unit outputs the temperature offset value, which is used to characterize the degree of deviation of the current on-chip temperature state from the calibration reference state.

[0041] Based on this, the controller selects the corresponding piecewise temperature coefficient from the temperature compensation parameter set according to the temperature offset interval in which the temperature offset is located, and inputs the temperature offset and the selected piecewise temperature coefficient into the temperature compensation calculation unit. The temperature compensation calculation unit performs gain processing on the temperature offset within the current temperature offset interval according to the selected piecewise temperature coefficient, and outputs a temperature compensation signal. Specifically, the temperature offset is the difference between the stable temperature detection value and the temperature reference value, and the temperature compensation signal is obtained by multiplying the temperature offset by the piecewise temperature coefficient corresponding to the current temperature offset interval. If expressed symbolically, then: ; ; in, This is the temperature offset. To stabilize the temperature measurement, As a temperature reference quantity, For temperature compensation signal, For the current number The segmented temperature coefficients corresponding to each temperature offset interval. and They use the same expression form; when both are represented by temperature detection code values, This represents the difference between the temperature detection code values; when both are expressed as temperature values... This represents the temperature difference. It is used to map the temperature offset into a temperature compensation signal. Its sign is determined by the temperature drift direction of the airflow sensor front end within the corresponding temperature offset interval, and its amplitude is determined by the temperature calibration process based on the temperature drift amplitude within the corresponding interval.

[0042] The temperature compensation signal serves as the input for subsequently generating the oscillation control quantity and the comparison threshold. The oscillation compensation coefficient is used to convert the temperature compensation signal into an expression that can be superimposed on the oscillation control reference quantity, and the threshold compensation coefficient is used to convert the temperature compensation signal into an expression that can be superimposed on the comparison threshold reference quantity; thus, the oscillation control quantity and the oscillation control reference quantity adopt the same expression form, and the comparison threshold adopts the same expression form.

[0043] When the temperature offset crosses different temperature offset intervals, the controller switches to the corresponding segmented temperature coefficient based on the boundary value of the temperature offset interval. The segmented temperature coefficients of adjacent temperature offset intervals are determined by the temperature calibration process combined with the changes in the temperature compensation signal at the boundary. When the temperature offset crosses the boundary value of an adjacent temperature offset interval, the controller switches to the corresponding segmented temperature coefficient based on the comparison result between the current temperature offset and the boundary value of the temperature offset interval, and continuously updates the temperature compensation signal before and after the switch according to the changes in the temperature compensation signal at the boundary, so as to reduce the impact of abrupt changes in the temperature compensation signal during interval switching. Therefore, the temperature compensation signal does not rely on a single fixed linear coefficient, but calls the corresponding calibration coefficient according to the interval in which the temperature offset is located, thereby reducing the impact of nonlinear temperature drift at the airflow sensor front end on the oscillation control quantity and the comparison threshold generation process.

[0044] Furthermore, when the controller reads the oscillation compensation coefficient, oscillation control reference quantity, threshold compensation coefficient, and comparison threshold reference quantity from the airflow front-end compensation parameter group, the controller reads the corresponding parameters written by the airflow front-end linkage calibration process from the airflow front-end compensation parameter group in the on-chip configuration data. The corresponding parameters are used to describe the cooperative correction relationship between the oscillation control quantity and the comparison threshold in the same airflow sensing capacitor charging and discharging link.

[0045] The oscillation control quantity and the comparison threshold are applied to the charging / discharging rhythm control process and the threshold determination process in the same gas flow sensing capacitor charging / discharging conversion link, respectively. The oscillation control quantity is used to adjust the charging path, discharging path, and switching rhythm of the gas flow sensing capacitor; the comparison threshold is used to adjust the determination boundary of the conversion node state by the threshold comparison circuit. The controller generates the oscillation control quantity and the comparison threshold separately based on the same temperature compensation signal, so that the oscillation circuit and the threshold comparison circuit perform temperature drift compensation for the conversion process and the determination process in the same gas flow sensing capacitor conversion link, respectively.

[0046] The polarity of the oscillation compensation coefficient and the threshold compensation coefficient is determined by the airflow front-end calibration process. The airflow front-end calibration process records the offset direction of the oscillation output and threshold judgment under different on-chip temperature conditions, and configures the oscillation compensation coefficient and the threshold compensation coefficient to have a gain polarity opposite to the corresponding offset direction; the controller performs gain processing on the temperature compensation signal accordingly, so that the oscillation control quantity and the comparison threshold are adjusted in the direction of offsetting temperature drift.

[0047] Furthermore, the process of determining the oscillation compensation coefficient and threshold compensation coefficient in the airflow front-end calibration procedure includes: selecting multiple temperature points within the calibration temperature range, and using the oscillation output state and threshold judgment state at the calibration reference temperature point as reference states; recording the offset direction and amplitude of the oscillation circuit output relative to the reference state, and the offset direction and amplitude of the threshold comparison circuit judgment result relative to the reference state at each temperature point. The controller generates a temperature compensation signal based on the stable temperature detection quantity corresponding to each temperature point, and proportionally matches the oscillation output offset amplitude with the corresponding temperature compensation signal to obtain the amplitude of the oscillation compensation coefficient; proportionally matches the threshold judgment offset amplitude with the corresponding temperature compensation signal to obtain the amplitude of the threshold compensation coefficient. The signs of the oscillation compensation coefficient and threshold compensation coefficient are taken in the opposite direction to the corresponding offset direction, so that the oscillation correction amount and threshold correction amount formed after the subsequent temperature compensation signal is amplified and match the temperature drift amount of the corresponding circuit in amplitude, and act in the direction of canceling the temperature drift in direction. Therefore, the oscillation compensation coefficient and threshold compensation coefficient are not arbitrarily set fixed constants, but compensation parameters determined by the airflow front-end calibration procedure based on the temperature drift direction and drift amplitude.

[0048] Specifically, when the temperature compensation signal is amplified according to the oscillation compensation coefficient and superimposed with the oscillation control reference value to obtain the oscillation control value, the controller inputs the temperature compensation signal and the oscillation compensation coefficient into the oscillation control arithmetic unit, and multiplies the temperature compensation signal with the oscillation compensation coefficient to obtain the oscillation correction value. The oscillation correction value and the oscillation control reference value use the same expression form, so that the two can be added together to form the oscillation control value. The oscillation compensation coefficient is determined according to the aforementioned polarity configuration principle, so that the oscillation correction value changes in the direction of offsetting the oscillation temperature drift; the controller adds the oscillation correction value to the oscillation control reference value to form the oscillation control value, so that the oscillation control value simultaneously includes the calibration reference of the airflow sensor front end and the temperature correction information.

[0049] Furthermore, when the oscillation control quantity is input into the oscillation circuit at the front end of the airflow sensor to compensate for the charging and discharging conversion process of the airflow sensor capacitor, the oscillation control quantity is output from the controller to the control terminal of the oscillation circuit. The oscillation circuit adjusts the charging path, discharging path and switching rhythm of the airflow sensor capacitor according to the oscillation control quantity, so that the charging and discharging conversion offset caused by temperature changes is corrected during the capacitor conversion stage.

[0050] Specifically, the temperature compensation signal is amplified according to the threshold compensation coefficient and then superimposed with a comparison threshold reference value to obtain the comparison threshold. The controller then inputs the temperature compensation signal and the threshold compensation coefficient into the threshold calculation unit and multiplies the temperature compensation signal by the threshold compensation coefficient to obtain the threshold correction value. The threshold correction value and the comparison threshold reference value use the same expression form, allowing them to be added together to form the comparison threshold. The threshold compensation coefficient is determined according to the aforementioned polarity configuration principle, causing the threshold correction value to change in the direction of offsetting the temperature drift in threshold determination. The controller adds the threshold correction value to the comparison threshold reference value to form the comparison threshold, allowing the comparison threshold and the oscillation control quantity to act together on the same airflow sensing capacitance conversion link.

[0051] Then, the comparison threshold is input to the threshold comparison circuit at the front end of the airflow sensor. When compensating for the charging and discharging conversion judgment process of the airflow sensor capacitor, the comparison threshold is output by the controller to the reference terminal of the threshold comparison circuit. The threshold comparison circuit compares the detection signal formed after the charging and discharging conversion of the airflow sensor capacitor with the comparison threshold, and outputs the airflow judgment signal after temperature compensation based on the comparison result.

[0052] When at least one of the oscillation control quantity and the comparison threshold reaches the working range boundary of the airflow sensor front end, the controller performs amplitude limiting processing according to the working range boundary values ​​of the oscillation control quantity and the comparison threshold in the airflow front end compensation parameter group. Specifically, the controller compares the currently generated oscillation control quantity with the working range boundary value of the oscillation control quantity. If the oscillation control quantity exceeds its upper limit, it is output to the oscillation circuit according to the upper limit; if the oscillation control quantity is lower than its lower limit, it is output to the oscillation circuit according to the lower limit. The controller also compares the currently generated comparison threshold with the working range boundary value of the comparison threshold. If the comparison threshold exceeds its upper limit, it is output to the threshold comparison circuit according to the upper limit; if the comparison threshold is lower than its lower limit, it is output to the threshold comparison circuit according to the lower limit. Thus, the oscillation circuit and the threshold comparison circuit are maintained within the operating range capable of charge / discharge conversion and threshold determination within the calibrated temperature range.

[0053] Therefore, the temperature detection quantity, stable temperature detection quantity, temperature offset quantity, temperature compensation signal, oscillation control quantity, and comparison threshold form a continuous data stream, enabling the charging and discharging conversion process and judgment process of the airflow sensing capacitor to be collaboratively corrected according to the on-chip temperature state, which helps to improve the consistency of airflow detection in the charging integrated environment.

[0054] Furthermore, the process of acquiring the external charging voltage and determining the external charging access status based on the external charging voltage includes reading the external charging access threshold and the external charging disconnection threshold, acquiring the external charging voltage to obtain the external charging voltage sample quantity, filtering the external charging voltage sample quantity to obtain a stable external charging voltage quantity, performing hysteresis comparison, setting the external charging access status, and resetting the external charging access status.

[0055] Specifically, the acquisition of the external charging access threshold and the external charging disconnection threshold includes the controller reading the corresponding threshold written by the charging interface calibration process from the charging access judgment parameter group in the on-chip configuration data, and using the external charging access threshold as the judgment boundary for entering the access state and the external charging disconnection threshold as the judgment boundary for exiting the access state, so that subsequent access judgments have a comparison basis from the on-chip configuration data.

[0056] During the sampling process, the global state machine logic outputs a sampling enable signal to the external charging voltage sampling channel. The external charging voltage is input to the sampling channel by the charging interface detection node, and after input buffering and sample-and-hold processing, the external charging voltage sample quantity is formed, so that the voltage state of the external charging interface can be received by the controller.

[0057] After sampling, the external charging voltage sampling channel performs simulated smoothing on the sampled external charging voltage, and uses the smoothed voltage as the input to the hysteresis comparison logic as a stable external charging voltage. This processing is used to reduce the impact of short-cycle voltage fluctuations caused by interface contact disturbances and charging path switching on subsequent comparison results.

[0058] During the hysteresis comparison process, the stable external charging voltage is input into the hysteresis comparison logic and compared with the external charging access threshold and the external charging disconnection threshold, respectively. Based on the comparison results, the hysteresis comparison logic outputs the access validity judgment result, the disconnection validity judgment result, and the state maintenance result, so that different judgment boundaries are used for entering the access state and exiting the access state.

[0059] When the stable external charging voltage is greater than or equal to the external charging access threshold, the hysteresis comparison logic outputs a valid access judgment result to the global state machine logic. After confirming that the valid access judgment result continues to exist within the continuous sampling cycle, the global state machine logic sets the external charging access state and sends it to the charging path control process and output linkage adjustment process.

[0060] When the stable external charging voltage is less than the external charging disconnection threshold, the hysteresis comparison logic outputs a valid disconnection judgment result to the global state machine logic. After confirming that the valid disconnection judgment result persists within a continuous sampling cycle, the global state machine logic resets the external charging access state and causes the charging path control process and output linkage adjustment process to exit the corresponding operating state of external charging access.

[0061] Therefore, the external charging voltage sampling quantity, stable external charging voltage quantity, access threshold, disconnection threshold, and external charging access status form a continuous judgment link, enabling the external charging access status to be updated according to the hysteresis comparison result under the global state machine logic, and providing a state basis for subsequent PWM drive signal monitoring and dead zone window identification.

[0062] Furthermore, the process of identifying the dead zone window between the high-side transistor being turned off and the low-side transistor being turned on includes entering the PWM drive signal monitoring state when the external charging access state is set, acquiring the high-side PWM drive signal and the low-side PWM drive signal, generating the high-side turn-off edge flag, and generating the low-side turn-on edge flag; it also includes determining the start flag and end flag of the dead zone window and forming the dead zone window based on the start flag and end flag.

[0063] Specifically, entering the PWM drive signal monitoring state involves the global state machine logic receiving the setting result of the external charging access state, switching the running state to the PWM drive signal monitoring state, and outputting a monitoring enable signal to the PWM drive signal sampling logic, so that the dead window identification process corresponds to the charging drive process after the external charging access.

[0064] In PWM drive signal monitoring mode, the PWM drive signal sampling logic obtains the corresponding drive levels from the drive feedback nodes on the high-side gate drive output side and the low-side gate drive output side, respectively, and synchronizes the acquired high-side PWM drive signals and low-side PWM drive signals to the clock domain where the global state machine logic resides. The synchronized drive signals are used to generate sampled and confirmed edge flags; the edge flags reflect the level change state at the drive feedback nodes after sampling and confirmation, and serve as the logical basis for the global state machine logic to identify the high-side transistor turn-off and low-side transistor turn-on timings.

[0065] Specifically, the generation of the high-side turn-off edge flag includes the edge detection logic comparing the current sampling state and the previous sampling state of the high-side PWM drive signal. After the high-side PWM drive signal changes from an active level to an inactive level, the high-side turn-off edge flag is formed through drive feedback synchronization and sampling confirmation, so that the high-side transistor turn-off action is converted into a logic flag signal that can be recognized by the global state machine logic.

[0066] The generation of the low-side conduction edge flag involves the edge detection logic comparing the current sampling state and the previous sampling state of the low-side PWM drive signal. After the low-side PWM drive signal changes from an invalid level to an effective level, the low-side conduction edge flag is formed through drive feedback synchronization and sampling confirmation, so that the low-side transistor conduction action is converted into a logic flag signal that can be recognized by the global state machine logic.

[0067] When determining the dead window, the global state machine logic receives the high-side turn-off edge flag, registers it as a candidate start flag, and triggers the setting of the sampling enable signal based on the candidate start flag. The setting of the sampling enable signal does not wait for the delayed confirmation result of the candidate start flag. Simultaneously, the global state machine logic performs delayed confirmation of the candidate start flag based on the synchronization beat of the drive feedback signal; during the delayed confirmation period, the global state machine logic masks the repeating edge flags caused by transient ringing of the switch. The delayed confirmation is only used to determine whether the dead window corresponding to the candidate start flag is a valid dead window and to decide whether the count result obtained within the dead window should be written to the accumulation register. The global state machine logic registers the low-side turn-on edge flag as the end flag of the dead window to limit the interval between the high-side transistor exiting the turn-on state and the low-side transistor not yet entering the turn-on state.

[0068] Specifically, after detecting a high-side turn-off edge flag, the edge detection logic initiates a delayed count based on the synchronous sampling clock of the drive feedback signal. This delayed count corresponds to multiple preset sampling clock cycles, the number of which is pre-configured by the PWM drive signal monitoring logic based on the synchronous beat of the drive feedback signal and the duration of transient ringing during switching. Before the delayed count is complete, if the edge detection logic detects another edge change in the high-side PWM drive signal, the global state machine logic determines this edge change as a repeated edge flag caused by transient ringing during switching and marks the window corresponding to the candidate start flag as a window to be eliminated. When the delayed count is complete and no repeated edge flag is detected during this period, the global state machine logic marks the window corresponding to the candidate start flag as a valid dead-time window. For dead-time windows marked as windows to be eliminated, their internal counting results are not written to the accumulation register. Simultaneously, the global state machine logic sets the transition state recovery flag to reduce the impact of partial charge / discharge transitions within this window on subsequent cumulative sampling. After the sampling enable signal is reset, the capacitor frequency conversion circuit restores the state of the airflow sensing capacitor conversion node to the state saved at the end of the previous valid write window, based on the conversion state recovery flag. When the next dead zone window arrives, the capacitor frequency conversion circuit continues to perform charge and discharge conversion based on the restored conversion node state. When multiple windows to be rejected appear consecutively, the conversion state recovery is based on the conversion node state saved at the end of the previous valid write window, so as to reduce the impact of partial charge and discharge conversion within multiple windows to be rejected on subsequent cumulative sampling values.

[0069] Subsequently, the global state machine logic sets the dead zone window to the valid state after receiving the start flag, and resets the dead zone window to the valid state after receiving the end flag, so that the logic interval between the start flag and the end flag forms a dead zone window for subsequent airflow sampling and charging disturbance avoidance.

[0070] For the effective dead zone window, the global state machine logic outputs the effective dead zone window only when the start flag and end flag are obtained within the same drive monitoring cycle. When the low-side conduction edge flag does not appear within the corresponding drive monitoring cycle, the global state machine logic does not output the effective dead zone window, and resets the effective state of the dead zone window and clears the registered start flag at the end of the drive monitoring cycle; accordingly, the airflow sampling logic does not trigger sampling based on the floating window.

[0071] Therefore, the high-side PWM drive signal, the low-side PWM drive signal, the high-side turn-off edge flag, the low-side turn-on edge flag, and the dead-zone window form a continuous timing link, enabling airflow sensing sampling to be located within the dead-zone window after the high-side transistor is turned off and before the low-side transistor is turned on. Windows that do not meet the counting conditions are excluded through edge confirmation and validity screening. At the same time, the capacitor frequency conversion circuit disconnects the charging and discharging drive path outside the dead-zone window and maintains the conversion node state, which helps to reduce the switching disturbances during the power transistor conduction stage from directly entering the airflow sensing capacitor conversion link, thereby improving the stability of airflow detection under charging access conditions.

[0072] Furthermore, the process of obtaining the pulse signal sequence includes setting the sampling enable signal, triggering the capacitor frequency conversion circuit to perform charge and discharge conversion on the airflow sensing capacitor, counting the conversion time to obtain the single-window sampling count value, resetting the sampling enable signal and latching the single-window sampling count value, continuing to trigger the charge and discharge conversion in the next dead window, accumulating the single-window sampling count value in the continuous dead windows, and performing threshold-triggered pulse generation processing on the accumulated sampling value.

[0073] In this embodiment, the continuously occurring dead-zone windows refer to dead-zone windows formed consecutively according to the timing sequence of the PWM drive signals. The global state machine logic outputs a sampling enable signal within the continuously occurring dead-zone windows to trigger the segmented charging and discharging conversion of the airflow sensing capacitor. The effective dead-zone window refers to a dead-zone window that has completed start and end confirmation and meets the minimum count threshold judgment condition; segmented cumulative sampling uses the effective dead-zone window written to the accumulation register as the sampling segment, and accumulates the continuously obtained single-window sample count values ​​according to the sampling order. The minimum count threshold is determined by the temperature calibration process and the airflow front-end calibration process based on the counting clock frequency, the circuit establishment process after the sampling enable signal is valid, the response time of the threshold comparison circuit, and the normal operating cycle of the airflow sensing front-end oscillation circuit.

[0074] Specifically, the minimum counting threshold is logically constrained by a dual-boundary closed-loop constraint: its lower limit is configured to be greater than the sum of the time required for the circuit setup process after the sampling enable signal is valid and the response time of the threshold comparison circuit at the counting clock frequency corresponding to the base perturbation code value; its upper limit is configured to be less than the maximum charge-discharge conversion counting code value that the normal dead-zone window pulse width can accommodate at the counting clock frequency under the normal operating cycle of the airflow sensing front-end oscillation circuit.

[0075] During the calibration process, the airflow front-end calibration procedure continuously collects single-window count results within different dead-zone windows under the baseline airflow condition, obtains an effective conversion count distribution that covers the lower limit and does not exceed the upper limit, and writes the statistical lower limit of this distribution as the minimum count threshold into the airflow front-end compensation parameter group. When the count result within the effective dead-zone window is not lower than the minimum count threshold, the count result is written into the accumulation register as a single-window sampled count value; when the count result within the effective dead-zone window is lower than the minimum count threshold, the count result of that window is not written into the accumulation register, and the current conversion state of the airflow sensing capacitor is saved according to the hold logic for continued conversion in the next effective dead-zone window.

[0076] The single-window sampling count value obtained within a single effective dead window is used as the segmented counting result for accumulation. It is not required to complete a full airflow sensing capacitor conversion cycle within a single dead window. After the dead window ends, the capacitor frequency conversion circuit maintains the current conversion state of the airflow sensing capacitor and continues to perform charge and discharge conversion based on the conversion state when the next effective dead window arrives. The single-window sampling count values ​​obtained within multiple effective dead windows are accumulated in the sampling order to form the cumulative sampling value.

[0077] Specifically, setting the sampling enable signal involves the global state machine logic receiving the start flag of the dead window, switching the sampling enable signal to an active state, and outputting the sampling enable signal to the sampling control terminal of the capacitor frequency conversion circuit, so that the charging and discharging conversion action of the airflow sensing capacitor is triggered synchronously according to the start flag of the dead window.

[0078] During the valid period of the sampling enable signal, the capacitor frequency conversion circuit receives the shared reference voltage and drives the charging and discharging paths of the airflow sensing capacitor according to the shared reference voltage, so that the airflow sensing capacitor forms a conversion process corresponding to the capacitance change caused by the airflow within the dead zone window.

[0079] Specifically, the acquisition of the single-window sampling count value includes: the on-chip counting clock branch provides a counting clock to the counting logic, and the counting logic counts the transition time of the airflow sensing capacitor while the sampling enable signal is active. The latching logic latches the count result as the single-window sampling count value only when the global state machine logic confirms a valid dead-time window and the count result within that window is not lower than the minimum counting threshold; otherwise, no latching operation is performed. For windows not written to the accumulation register, the current transition node state of the airflow sensing capacitor is still saved according to the hold logic so that the transition can continue when the next valid dead-time window arrives.

[0080] At the end of the dead-time window, the global state machine logic switches the sampling enable signal to an invalid state and controls the latch logic to save the single-window sampling count value corresponding to the current effective dead-time window. After the sampling enable signal is reset, the capacitor frequency conversion circuit shuts off the charging and discharging drive path and saves the charge state of the gas flow sensing capacitor conversion node through a complementary control holding switch and a low-leakage holding node. The saved charge state serves as the initial state for the next effective dead-time window conversion. The low-leakage holding node is used to reduce the effects of charge discharge and direct coupling during the holding period, but it does not mean that the charge state of the conversion node remains completely unchanged during the non-dead-time holding period.

[0081] Within the next dead-zone window, the global state machine logic re-sets the sampling enable signal after the start flag of the next dead-zone window appears. The capacitor frequency conversion circuit continues to drive the airflow sensing capacitor using the maintained conversion node state as the initial state for this charge-discharge conversion. The counting logic re-acquires the single-window sampling count value during the validity period of this sampling enable signal and sends this count value to the subsequent accumulation logic, so that the sampling results across the dead-zone window are sequentially accumulated at the digital accumulation level.

[0082] Subsequently, the accumulation logic receives the single-window sample count values ​​latched within consecutive valid dead-time windows according to the sampling order, and writes each single-window sample count value into the accumulation register for sequential accumulation. The single-window sample count value obtained within a single valid dead-time window participates in the accumulation as a segmented sampling result, and the transition time obtained segmented within multiple valid dead-time windows is synthesized into an accumulated sample value characterizing the change in airflow sensing capacitance; among them, invalid dead-time windows, windows that have not completed start and end confirmation, or windows whose counting results have not reached the minimum counting threshold do not participate in the accumulation update.

[0083] Specifically, the acquisition of the pulse signal sequence includes: after receiving the accumulated sampled value, the pulse generation logic compares the accumulated sampled value with a preset counting judgment threshold in the pulse generation logic. The counting judgment threshold is determined by the airflow front-end calibration process based on the single-window sampling counting range of the airflow sensing capacitance under the reference airflow state, the target pulse output frequency range, and the counting observation interval of the global state machine logic, and is written into the airflow front-end compensation parameter group or output linkage adjustment parameter group; specifically, the airflow front-end calibration process acquires the accumulated sampled value formed within the continuous effective dead zone window under the reference airflow state, and determines the judgment boundary for the accumulated sampled value to trigger a pulse transition based on the target pulse output frequency range and the counting observation interval of the global state machine logic, and uses this judgment boundary as the counting judgment threshold. The counting judgment threshold is used to determine the judgment boundary for the accumulated sampled value to trigger a pulse transition; when the accumulated sampled value reaches the counting judgment threshold, the edge detection logic outputs a level transition, and retains the remaining part of the accumulated sampled value exceeding the counting judgment threshold for the next comparison process. The pulse hold logic holds the level transition for at least one global state machine logic clock cycle to form a valid pulse that can be recognized by the global state machine logic. The generated pulse signal is then synchronized to the clock cycle of the global state machine logic via a synchronization register. A margin reserve register stores any remaining portion exceeding the counting threshold. When the remaining portion exceeds the storage range of the margin reserve register, the pulse generation logic, according to the airflow front-end calibration process or the pre-configured overflow handling method in the output linkage adjustment parameter group, either truncates the pulse according to the upper limit of the margin reserve register or triggers an additional pulse output according to a preset overflow flag. This overflow handling method remains fixed after being determined during the calibration phase and is not dynamically switched during operation. The pulse generation logic continuously outputs pulses according to the above comparison, transition, pulse hold, and margin reserve process, obtaining a pulse signal sequence corresponding to the airflow sensing capacitance conversion result.

[0084] Thus, the dead zone window, sampling enable signal, airflow sensor capacitance switching state, single-window sampling count value, cumulative sampling value, and pulse signal sequence form a continuous sampling link, enabling the airflow sensor capacitance to be segmented within the dead zone window after edge confirmation and validity screening, and forming a pulse signal sequence for subsequent airflow state level determination.

[0085] Furthermore, the process of adjusting the output control parameters in a coordinated manner includes reading the airflow reference count value, the airflow level determination coefficient and the linkage adjustment coefficient, performing edge counting on the pulse signal sequence to obtain the airflow detection count value, determining the airflow offset, obtaining the airflow state level, forming the linkage state index, determining the output control parameter adjustment level, and updating the load output duty cycle and charging current limit.

[0086] In this embodiment, the airflow state level is used to characterize the impact of the airflow channel state on the load operating state, and the voltage state signal is used to characterize the range of the energy storage unit terminal voltage. The global state machine logic combines the airflow state level and voltage state signal into a linked state index, so that the load output duty cycle and charging current limit are updated under the same state basis.

[0087] Specifically, the acquisition of the airflow reference count value, airflow level determination coefficient, and linkage adjustment coefficient includes the controller reading the corresponding parameters written by the airflow detection calibration and charging linkage calibration from the output linkage adjustment parameter group in the on-chip configuration data. The airflow reference count value is used to characterize the count reference quantity under the reference airflow state. The airflow level determination coefficient includes the airflow offset grading boundary obtained by the airflow front-end calibration process, which is used to divide the airflow offset into the corresponding airflow state level. The linkage adjustment coefficient is used to characterize the coordinated adjustment relationship between the airflow state level and the voltage state signal on the output control parameters. The output linkage adjustment parameter group also includes a state encoding relationship for converting the airflow state level and voltage state signal into digital fields. The linkage adjustment coefficient is determined by the airflow detection calibration and charging linkage calibration according to the adjustment requirements of the airflow state level, voltage state signal, and output control parameters, and written into the output linkage adjustment parameter group.

[0088] During edge counting, the edge counting logic receives the pulse signal sequence output by the pulse shaping logic and counts the valid edges within the counting observation interval defined by the pulse shaping cycle. The counting result is output as the airflow detection count value to the airflow offset calculation logic, so that the conversion result of the airflow sensing capacitance is converted into a digital quantity with a defined counting range.

[0089] Subsequently, the airflow offset calculation logic receives the airflow detection count value and the airflow reference count value, and calculates the difference between the airflow detection count value and the airflow reference count value to obtain the airflow offset amount with directional attributes. The airflow offset amount is used to retain the deviation magnitude and deviation direction of the current airflow state relative to the reference airflow state, and is sent to the level determination logic so that subsequent level determination can distinguish between positive and negative offsets.

[0090] Based on this, the level determination logic receives the airflow offset and the airflow level determination coefficient. The airflow level determination coefficient is determined by the airflow front-end calibration process after collecting airflow detection counts under the baseline airflow state, the low airflow reference state, and the high airflow reference state, and includes the classification boundary of the airflow offset. The level determination logic compares the current airflow offset with the classification boundary, determines the classification interval of the current airflow offset based on the comparison result, and determines the offset direction by combining the positive or negative attribute of the airflow offset; then, it maps the classification interval and offset direction to the corresponding airflow state level. The airflow state level includes at least normal airflow, high airflow, and low airflow, so that the continuously changing airflow offset is processed into a discrete level quantity that can be called by the global state machine logic.

[0091] Accordingly, the global state machine logic receives the airflow state level and the voltage state signal output by the charging comparator circuit, and converts the airflow state level into an airflow state digital field and the voltage state signal into a voltage state digital field according to the state coding relationship in the output linkage adjustment parameter group. In one embodiment, the airflow state digital field occupies two bits, where normal airflow, low airflow, and high airflow correspond to different airflow state codes; the voltage state digital field occupies two bits and is used to represent different voltage state intervals obtained by the charging comparator circuit through hysteresis comparison. The global state machine logic uses the airflow state digital field as the high-order field and the voltage state digital field as the low-order field, and concatenates them in a fixed field order to form a linkage state index. The value of the linkage state index corresponds to the storage order of the adjustment mapping items in the output linkage adjustment parameter group, so that the airflow detection result and the charging voltage state enter the same linkage adjustment link.

[0092] Based on the linkage state index, the global state machine logic locates the linkage adjustment coefficient matching the linkage state index in the output linkage adjustment parameter group. The output linkage adjustment parameter group stores multiple linkage adjustment coefficients according to the value order of the linkage state index, with the values ​​of the linkage state indexes corresponding one-to-one with the storage order of the linkage adjustment coefficients. In this embodiment, the linkage adjustment coefficient is a structured control parameter used for output linkage adjustment. Each linkage adjustment coefficient includes a load output duty cycle adjustment direction identifier, a load output duty cycle adjustment amplitude level identifier, a charging current limit adjustment direction identifier, and a charging current limit adjustment amplitude level identifier. The adjustment direction identifier indicates whether the corresponding output control parameter increases, decreases, or remains constant relative to the current state; the adjustment amplitude level identifier indicates the adjustment amplitude level of the corresponding output control parameter. The correspondence between the adjustment amplitude level and the actual adjustment step of the corresponding output control parameter is written into the output linkage adjustment parameter group by the charging linkage calibration process; wherein, the adjustment step corresponding to the load output duty cycle and the adjustment step corresponding to the charging current limit are configured according to their respective control quantity expression forms, and the two are converted into comparable or superimposed expression forms before entering the corresponding arithmetic unit. The global state machine logic reads the linkage adjustment coefficient that matches the current linkage state index, and determines the adjustment level of the output control parameters according to the adjustment direction identifier and adjustment amplitude level identifier in the linkage adjustment coefficient, so that the load output duty cycle and charging current limit are constrained by the same linkage judgment result.

[0093] In this embodiment, the voltage status digital field corresponds to different codes for undervoltage, low normal charging, high normal charging, and near full charge. When the airflow is high and the voltage is in the low normal charging stage, the corresponding linkage adjustment coefficient can indicate that the load output duty cycle decreases by one level and that the charging current limit remains unchanged. The above example illustrates the lookup relationship between the linkage status index and the linkage adjustment coefficient. The specific adjustment level is determined by the adjustment amplitude level in the output linkage adjustment parameter group. When the adjustment directions corresponding to the linkage status indices obtained from adjacent counting observation intervals are opposite, in one implementation, the global state machine logic maintains the output control parameter adjustment level determined in the previous counting observation interval; in another implementation, the global state machine logic updates the output control parameter adjustment level after the airflow status level and voltage status signal continuously satisfy the same adjustment direction.

[0094] Finally, the output control logic generates adjustment targets for the load output duty cycle and the charging current limit according to the adjustment levels of the output control parameters. These adjustment targets represent whether the corresponding output control parameter increases, decreases, or remains constant relative to the current state. The global state machine logic coordinates the writing process of the two adjustment targets under the same linkage state index. The load output duty cycle is sent to the load drive control process, and the charging current limit is sent to the charging current adjustment process, ensuring that both enter their respective control links under the same linkage judgment result.

[0095] Regarding parameter updates, after the global state machine logic completes the counting observation interval corresponding to the current pulse signal sequence, it executes the output control parameter update based on the current linkage state index, and performs the next adjustment judgment after forming a new airflow detection count value in the next counting observation interval.

[0096] Thus, the pulse signal sequence, airflow detection count value, airflow offset, airflow state level, voltage state signal and output control parameters form a linkage adjustment link according to the counting observation interval, so that the load output duty cycle and charging current limit can enter the corresponding control process based on the same linkage state index.

[0097] Example 2: In one implementation, to reduce the impact of changes in the charge state of the switching nodes during the non-dead-zone hold period on the segmented sampling results, the controller can also perform charge compensation processing during the hold period of the current switching state of the airflow sensing capacitor. This charge compensation processing is suitable for operating states where changes in the charge state of the switching nodes are significant during the non-dead-zone hold period, and is used to reduce the impact of repeatable leakage current and slowly changing node drift during the hold period on the subsequent segmented cumulative sampling results.

[0098] Specifically, after the dead-zone window ends and the sampling enable signal is reset, the capacitor frequency conversion circuit disconnects the charging and discharging drive path of the airflow sensing capacitor and saves the switching node state of the airflow sensing capacitor through a low-leakage holding node. The controller determines the leakage compensation amount based on the leakage compensation relationship obtained during the holding calibration process. This leakage compensation amount is used to characterize the repeatable change direction and degree of change of the switching node state within the non-dead-zone holding period. In subsequent non-dead-zone holding periods, the on-chip compensation branch performs limited compensation on the airflow sensing capacitor switching node according to this leakage compensation amount to reduce the impact of repeatable leakage and slow-changing node drift on the subsequent segmented cumulative sampling results. The leakage compensation amount is not used to cancel random noise components, which are tolerated by the grading boundaries in the continuous dead-zone window accumulation and airflow state level determination process.

[0099] In the above manner, the airflow sensing capacitor maintains its state outside the dead zone window and performs limited compensation based on the leakage compensation relationship obtained during the calibration process. When the compensated transition state does not meet the grade boundary requirements corresponding to the airflow level determination coefficient, the controller clears the current accumulated sampling value and restarts the segmented charging and discharging transition of the airflow sensing capacitor in the next effective dead zone window.

[0100] In one implementation, to mitigate the impact of asynchronous thermal response between the on-chip temperature detection location and the airflow sensor front end location on the compensation process, the controller may also introduce a temperature change trend correction when generating the temperature compensation signal.

[0101] In this process, the controller not only determines the temperature offset based on the stable temperature detection value and the temperature reference value, but also determines the temperature change trend value based on the changes in the stable temperature detection value at adjacent sampling times. The temperature change trend value is used to indicate whether the on-chip temperature is in a state of rising, falling, or relatively stable change.

[0102] The airflow front-end compensation parameter set may include temperature trend correction relationships written in the temperature calibration process. The controller generates a trend compensation quantity based on the temperature change trend and the temperature trend correction relationship, and uses the trend compensation quantity and the compensation results corresponding to the temperature offset to form a temperature compensation signal. After the trend compensation quantity participates in the generation of the temperature compensation signal, the controller still performs boundary limiting processing on the oscillation control quantity and comparison threshold generated by the temperature compensation signal according to the boundary values ​​of the oscillation control quantity working range and the comparison threshold working range in the airflow front-end compensation parameter set. When the trend compensation quantity causes the oscillation control quantity or comparison threshold to approach the corresponding working range boundary, the controller outputs according to the corresponding boundary value to prevent the trend compensation quantity from causing the airflow sensor front-end to temporarily leave the working range. The oscillation control quantity and comparison threshold after boundary limiting processing are then input into the oscillation circuit and the threshold comparison circuit, respectively.

[0103] When the on-chip temperature is in a state of continuous change, the trend compensation amount is used to feedforward correct the temperature compensation signal; when the on-chip temperature change tends to be stable, the controller gradually reduces the participation of the trend compensation amount in the temperature compensation signal according to the degree of decrease of the temperature change trend amount, until the trend compensation amount no longer participates in the generation of the current temperature compensation signal.

[0104] In this way, the temperature compensation signal can not only reflect the current temperature offset state, but also correct the compensation process of the airflow sensor front end in combination with the on-chip temperature change trend. This correction process is constrained by the boundary values ​​of the oscillation control quantity's working range and the comparison threshold's working range. This processing helps reduce the impact of the thermal response difference between the temperature detection location and the airflow sensor front end location on the generation process of the oscillation control quantity and the comparison threshold.

[0105] In one implementation, to reduce the impact of transient airflow disturbances on the adjustment process of output control parameters, the global state machine logic can also perform anti-jitter processing on the continuously obtained airflow state levels before forming the linkage state index based on the airflow state level and voltage state signal.

[0106] To this end, the global state machine logic establishes a timing window for storing historical airflow state levels. The timing window receives airflow state levels formed within multiple counting observation intervals and determines the current airflow state level for linkage adjustment based on the airflow state level that appears most frequently within the window.

[0107] The length of the timing window can be adjusted according to the current state of the charging current limit. When the charging current limit corresponds to a higher charging load state, the global state machine logic extends the timing window so that transient airflow spikes are less likely to directly change the current airflow state level used for linkage regulation; when the charging current limit corresponds to a lower charging load state, the global state machine logic shortens the timing window so that the airflow state level can participate in the subsequent output control parameter adjustment more quickly.

[0108] The airflow state level after anti-shake processing is combined with the voltage state signal to form a linkage state index. The global state machine logic determines the output control parameter adjustment level based on this linkage state index, and sends the adjustment target of the load output duty cycle to the load drive control process and the adjustment target of the charging current limit to the charging current adjustment process.

[0109] In this way, the airflow state level is processed by a timing window related to the charging current state before entering the output linkage adjustment link. This helps to reduce the impact of short-term airflow disturbances on the load output duty cycle and charging current limit adjustment process, and facilitates the two output control parameters to enter the corresponding control links under the same linkage judgment result.

[0110] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A high-precision charging management and airflow sensing integrated method, characterized in that, Includes the following steps: Read the on-chip configuration data, generate a shared reference voltage using the energy storage unit terminal voltage as the power supply, and input the shared reference voltage into the charging comparator circuit and the capacitor frequency conversion circuit respectively to obtain the voltage status signal of the charging comparator circuit. Temperature is collected by the on-chip temperature detection circuit, and temperature drift compensation is performed based on the temperature detection to obtain a temperature compensation signal. The oscillation circuit and threshold comparison circuit at the front end of the airflow sensor are then compensated based on the temperature compensation signal. Under the control of the global state machine logic, the external charging voltage is acquired and the external charging connection status is determined; when the external charging connection status is reached, the dead zone window between the high-side transistor being turned off and the low-side transistor being turned on is identified based on the PWM drive signal of the power switch transistor. Within a continuous dead zone window, a sampling enable signal is output to trigger a capacitor frequency conversion circuit. Based on a shared reference voltage and the front end of the airflow sensor, the circuit performs segmented charging and discharging conversion on the airflow sensor capacitor and accumulates the latched single-window sampling count value to obtain a pulse signal sequence. The airflow state level is determined by the pulse signal sequence. The output control parameters are adjusted in conjunction with the airflow level and voltage status signals.

2. The high-precision charging management and airflow sensing integration method according to claim 1, characterized in that, The reading of on-chip configuration data includes: reading the temperature compensation parameter group, airflow front-end compensation parameter group, charging access judgment parameter group and output linkage adjustment parameter group pre-written into the on-chip configuration data.

3. The high-precision charging management and airflow sensing integration method according to claim 1, characterized in that, The process of generating a shared reference voltage and inputting it into the charging comparator circuit and the capacitor frequency conversion circuit includes: stabilizing the voltage at the energy storage unit terminals to obtain the on-chip power supply voltage; driving the on-chip bandgap reference voltage network based on the on-chip power supply voltage to output the original reference voltage; chopping and stabilizing the original reference voltage to obtain the shared reference voltage; inputting the shared reference voltage into the charging comparator circuit and inputting the energy storage unit terminal voltage into the charging comparator circuit after voltage division and filtering, and obtaining the voltage status signal after hysteresis comparison; and inputting the shared reference voltage into the capacitor frequency conversion circuit as the reference input quantity for the charging and discharging conversion of the airflow sensing capacitor.

4. The high-precision charging management and airflow sensing integration method according to claim 1, characterized in that, The compensation of the oscillation circuit and threshold comparison circuit of the airflow sensor front end based on the temperature compensation signal includes: reading the temperature reference quantity and segmented temperature coefficient from the temperature compensation parameter group; acquiring the temperature detection quantity through the on-chip temperature detection circuit and filtering the temperature detection quantity to obtain a stable temperature detection quantity; determining the temperature offset quantity based on the difference between the stable temperature detection quantity and the temperature reference quantity; performing gain processing on the temperature offset quantity according to the segmented temperature coefficient of the interval in which the temperature offset quantity is located to obtain a temperature compensation signal; reading the oscillation compensation coefficient, oscillation control reference quantity, threshold compensation coefficient, and comparison threshold reference quantity from the airflow front end compensation parameter group; performing gain processing on the temperature compensation signal according to the oscillation compensation coefficient and superimposing the oscillation control reference quantity to obtain an oscillation control quantity; inputting the oscillation control quantity into the oscillation circuit of the airflow sensor front end to compensate for the charging and discharging conversion process of the airflow sensor capacitor; performing gain processing on the temperature compensation signal according to the threshold compensation coefficient and superimposing the comparison threshold reference quantity to obtain a comparison threshold; inputting the comparison threshold into the threshold comparison circuit of the airflow sensor front end to compensate for the charging and discharging conversion determination process of the airflow sensor capacitor.

5. The high-precision charging management and airflow sensing integration method according to claim 1, characterized in that, The process of acquiring the external charging voltage and determining the external charging access status based on the external charging voltage includes: reading the external charging access threshold and the external charging disconnection threshold from the charging access judgment parameter group; acquiring the external charging voltage under the logic control of the global state machine to obtain the external charging voltage sample quantity; filtering the external charging voltage sample quantity to obtain a stable external charging voltage quantity; performing a hysteresis comparison between the stable external charging voltage quantity and the external charging access threshold and the external charging disconnection threshold; setting the external charging access status when the stable external charging voltage quantity is greater than or equal to the external charging access threshold; and resetting the external charging access status when the stable external charging voltage quantity is less than the external charging disconnection threshold.

6. The high-precision charging management and airflow sensing integration method according to claim 1, characterized in that, The method for identifying the dead zone window between the high-side transistor being turned off and the low-side transistor being turned on includes: when the external charging access state is set, causing the global state machine logic to enter the PWM drive signal monitoring state; in the PWM drive signal monitoring state, acquiring the high-side PWM drive signal and the low-side PWM drive signal; performing effective-to-invalid level transition detection on the high-side PWM drive signal to obtain the high-side turn-off edge flag; performing invalid-to-effective level transition detection on the low-side PWM drive signal to obtain the low-side turn-on edge flag; using the high-side turn-off edge flag as the start flag of the dead zone window and the low-side turn-on edge flag as the end flag of the dead zone window; and forming the dead zone window based on the start flag and the end flag.

7. The high-precision charging management and airflow sensing integration method according to claim 1, characterized in that, The obtained pulse signal sequence includes: setting the sampling enable signal when the start flag of the dead window appears; triggering the capacitor frequency conversion circuit to charge and discharge the airflow sensing capacitor based on the shared reference voltage while the sampling enable signal is active; counting the conversion time of the airflow sensing capacitor to obtain a single-window counting result while the sampling enable signal is active; resetting the sampling enable signal when the end flag of the dead window appears, and latching the single-window sampling count value as a single-window sample count value when the single-window count result is not lower than the minimum counting threshold in the airflow front compensation parameter group, while maintaining the current conversion state of the airflow sensing capacitor; triggering the capacitor frequency conversion circuit to continue charging and discharging based on the current conversion state when the start flag of the next dead window appears; accumulating the single-window sampling count values ​​latched in consecutive dead windows according to the sampling order to obtain an accumulated sampling value; and performing threshold-triggered pulse generation processing on the accumulated sampling value to obtain a pulse signal sequence.

8. The high-precision charging management and airflow sensing integration method according to claim 1, characterized in that, The linkage adjustment of the output control parameters includes: reading the airflow reference count value and airflow level determination coefficient from the output linkage adjustment parameter group, wherein the airflow level determination coefficient includes the grading boundary of the airflow offset; performing edge counting on the pulse signal sequence to obtain the airflow detection count value; determining the airflow offset based on the difference between the airflow detection count value and the airflow reference count value; determining the level based on the comparison result between the airflow offset and the grading boundary to obtain the airflow state level; combining the airflow state level and the voltage state signal into a linkage state index; locating the linkage adjustment coefficient in the output linkage adjustment parameter group according to the linkage state index, and determining the output control parameter adjustment level according to the adjustment direction and adjustment amplitude level indicated by the linkage adjustment coefficient; and updating the load output duty cycle and charging current limit in the output control parameters according to the output control parameter adjustment level.

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