CN114583784A - Current calibration method, calibration device and storage medium of BUCK circuit - Google Patents

Abstract

The invention is suitable for the technical field of power supplies, and provides a current calibration method, calibration equipment and a storage medium of a BUCK circuit, wherein the method comprises the following steps: acquiring input voltage and output voltage of the BUCK circuit; determining a current compensation coefficient according to the input voltage and the output voltage; and calibrating the output current of the BUCK circuit obtained by sampling according to the current compensation coefficient to obtain the target output current. The invention compensates the current obtained by sampling the midpoint in real time according to the input voltage and the output voltage, so that the current is accurate under the voltage of the full range, and the constant current charging can be realized.

Description

Current calibration method, calibration device and storage medium of BUCK circuit

technical field

The invention belongs to the technical field of power supply, and in particular relates to a current calibration method of a buck circuit, a calibration device and a storage medium.

Background technique

Buck circuits, also known as step-down circuits, are widely used in charging circuits and can be used to charge batteries. Figure 1 shows the circuit schematic of the BUCK circuit. In practical applications, the DMA sampling method or the midpoint sampling method is usually used to sample the output current of the BUCK circuit, and control the output current (charging current) accordingly. Because the DMA sampling method has many sampling points, it will occupy more memory of the controller, and the control is slightly delayed, so the midpoint sampling method is more favored.

However, when the buck circuit needs to be used to charge different batteries, the buck circuit will work in a DCM (Discontinuous Conduction Mode, discontinuous conduction mode) mode due to the change of the charging voltage. When the buck circuit works in DCM mode, since the inductor current is 0 for a period of time in one cycle, there is a deviation between the output current collected by the midpoint sampling method and the actual output current, which needs to be used after a single curve calibration. After calibration, if the input voltage or output voltage changes, the current will still deviate, and constant current charging cannot be guaranteed.

SUMMARY OF THE INVENTION

In view of this, embodiments of the present invention provide a current calibration method, calibration device, and storage medium for a buck circuit, so as to solve the problem that when the input voltage or output voltage changes in the prior art, the midpoint sampling current is inaccurate, and a constant current cannot be guaranteed. charging problem.

A first aspect of the embodiments of the present invention provides a current calibration method for a buck circuit, where the buck circuit operates in a DCM mode; the above method includes:

Obtain the input voltage and output voltage of the buck circuit;

Determine the current compensation coefficient according to the input voltage and output voltage;

The output current of the sampled BUCK circuit is calibrated according to the current compensation coefficient to obtain the target output current.

A second aspect of the embodiments of the present invention provides a current calibration device for a buck circuit, where the buck circuit operates in a DCM mode; the above-mentioned device includes:

The voltage acquisition module is used to acquire the input voltage and output voltage of the buck circuit;

The compensation coefficient determination module is used to determine the current compensation coefficient according to the input voltage and output voltage;

The current calibration module is used for calibrating the sampled output current of the buck circuit according to the current compensation coefficient to obtain the target output current.

A third aspect of the embodiments of the present invention provides a calibration device, including a memory, a processor, and a computer program stored in the memory and running on the processor, and the processor implements the first embodiment of the present invention when the processor executes the computer program. Aspects provide steps of a current calibration method for a buck circuit.

A fourth aspect of the embodiments of the present invention provides a computer-readable storage medium, where the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the current of the buck circuit provided in the first aspect of the embodiment of the present invention is implemented Steps of the calibration method.

Embodiments of the present invention provide a current calibration method, calibration device, and storage medium for a buck circuit. The method includes: acquiring an input voltage and an output voltage of a buck circuit; determining a current compensation coefficient according to the input voltage and the output voltage; The coefficient calibrates the sampled output current of the buck circuit to obtain the target output current. The embodiment of the present invention performs real-time compensation on the current sampled at the midpoint according to the input voltage and the output voltage, so that the current sampling accuracy of the buck circuit under the full range voltage of the DCM mode is greatly improved, and the DMA sampling method does not need to be used for current sampling to improve sampling Therefore, the sampling delay can be reduced, and the constant current charging can be realized more stably.

Description of drawings

In order to illustrate the technical solutions in the embodiments of the present invention more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only for the present invention. In some embodiments, for those of ordinary skill in the art, other drawings can also be obtained according to these drawings without any creative effort.

Figure 1 is the circuit schematic diagram of the BUCK circuit;

Figure 2 is a waveform diagram of key components when the BUCK circuit works in DCM mode;

3 is a schematic flow chart of the realization of a current calibration method of a BUCK circuit provided by an embodiment of the present invention;

4 is a schematic diagram of a current calibration device of a BUCK circuit provided by an embodiment of the present invention;

FIG. 5 is a schematic diagram of a calibration device provided by an embodiment of the present invention.

Detailed ways

In the following description, for the purpose of illustration rather than limitation, specific details such as specific system structures and technologies are set forth in order to provide a thorough understanding of the embodiments of the present invention. However, it will be apparent to those skilled in the art that the present invention may be practiced in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to obscure the description of the present invention with unnecessary detail.

In order to illustrate the technical solutions of the present invention, specific embodiments are used to illustrate the following.

Figure 1 shows the circuit schematic of the BUCK circuit. When the switch transistor drive signal is high, the switch transistor Q1 is turned on, the energy storage inductor L1 is magnetized, the current flowing through the energy storage inductor L1 increases linearly, and the capacitor C1 is charged at the same time to supply energy to the load R1. When the switch drive signal is low, the switch Q1 is turned off, the energy storage inductor L1 discharges through the diode D1, the current flowing through the energy storage inductor L1 decreases linearly, and the capacitor C1 discharges to supply energy to the load R1.

The BUCK circuit has three operating modes:

CCM (Continuous Conduction Mode, continuous conduction mode), in one switching cycle, the current of the energy storage inductor L1 will not reach 0.

BCM (Boundary Conduction Mode, boundary or boundary line conduction mode), when the current of the energy storage inductor L1 is 0, the switching tube Q1 is immediately turned off, the switching cycle is dynamic, and the frequency changes.

In DCM (Discontinuous Conduction Mode, discontinuous conduction mode), in one switching cycle, the current of the energy storage inductor L1 will always reach 0.

In the prior art, a buck circuit is usually used as a charging circuit in a DCM mode, and the waveform diagram of its key components is shown in FIG. 2 . In the DCM mode, during a switching cycle, the current of the energy storage inductor L1 returns to zero for a period of time.

T为驱动信号的开关周期。When using the BUCK circuit to charge the battery with constant current, it is usually necessary to sample the charging current. In the current technology, the mid-point sampling method is usually used to sample the charging current (the output current of the BUCK circuit), that is, the sampling is performed at the middle time (T _on /2) of the high level of the driving signal, the number of sampling points is small, and the DSP resource occupation is relatively high less, and the sampling control is fast. However, since the current of the energy storage inductor L1 returns to zero for a period of time in one cycle, the sampled current I' _o needs to be corrected to obtain the actual current I _o ,

T is the switching period of the driving signal.

However, with the progress of charging, if the output voltage or input voltage of the buck circuit changes, the T _d duration will also change, and the above correction formula is no longer applicable, resulting in a large deviation between the sampling current and the actual current, which affects the accuracy of sampling , which cannot guarantee constant current charging.

Based on the above problems, referring to FIG. 3 , an embodiment of the present invention provides a current calibration method for a buck circuit, where the buck circuit operates in a DCM mode; the above method includes:

S101: Obtain the input voltage and output voltage of the buck circuit;

S102: Determine the current compensation coefficient according to the input voltage and the output voltage;

S103 : calibrate the sampled output current of the buck circuit according to the current compensation coefficient to obtain a target output current.

Since the deviation between the sampled current and the actual current is related to the input voltage and the output voltage, in the embodiment of the present invention, the sampled current is calibrated and corrected in real time according to the input voltage and the output voltage, so that the current of the buck circuit under the full range of voltage in the DCM mode is corrected. The sampling accuracy is greatly improved, and there is no need to use the DMA sampling method for current sampling to improve the sampling accuracy, so that the sampling delay can be reduced, and the constant current charging can be realized more stably.

In some embodiments, S102 may include:

S1021: Obtain the duty ratio of the driving signal of the BUCK circuit;

S1022: Determine the current compensation coefficient according to the duty ratio of the driving signal, the input voltage and the output voltage.

In some embodiments, S1022 may include:

1. According to the duty cycle of the driving signal, the input voltage and the output voltage, the current compensation coefficient is calculated by the first formula;

The first formula can be:

Among them, D is the duty cycle of the drive signal, U _in is the input voltage, and U ₀ is the output voltage.

In the embodiment of the present invention, referring to FIG. 1 and FIG. 2 , when the switch tube Q1 is turned on (in the T _on period), the voltage drop of the energy storage inductor L1 is U _L1 =U _in -U _o ; the peak current of the energy storage inductor L1 The formula for calculating ΔI is:

When the switch tube Q1 is turned off, when the energy storage inductor L1 freewheels (within the T _d period), the voltage drop of the energy storage inductor L1 is U _L2 =U _o ; when the energy storage inductor L1 freewheels, the Voltage drop and current are both 0.

According to the inductance volt-second balance method, U _L1 *T _on =U _L2 *T _d , then we can get:

In one switching cycle, the calculation formula of the average output current I ₀ of the buck circuit is:

Substituting formula (3) into formula (4) can get:

结合公式(5)可以得到：When sampling at the midpoint, the current actually sampled

Combining formula (5), we can get:

When the buck circuit works in DCM mode, the actual current and the sampled current are inconsistent. The calculation formula of the actual current I _o is:

作为补偿系数，乘以采样电流得到BUCK电路的实际电流值，计算过程简单，计算结果准确，可保证稳定BUCK电流稳定的恒流输出。It can be seen from this that the actual current value can be calculated by multiplying the sampling current I' _o by a coefficient. Therefore, in the embodiment of the present invention, the

As a compensation coefficient, multiply the sampling current to obtain the actual current value of the buck circuit. The calculation process is simple and the calculation result is accurate, which can ensure a stable constant current output of a stable buck current.

In some embodiments, S103 may include:

S1031: Multiply the sampled output current of the buck circuit by a current compensation coefficient to obtain a target output current.

Based on the above, in the embodiment of the present invention, the current compensation coefficient is determined according to the input voltage and the output voltage, and then the sampled current is multiplied by the current compensation coefficient to obtain the target output current, that is, the actual output current. The calculation process is simple, and the calculated target output The current is accurate.

In some embodiments, before S1021, S102 may further include:

S1023: within a preset time period, obtain the duty ratios of the control loops of a plurality of buck circuits to form a first sequence;

S1024: Filter the first sequence to obtain the filtered first sequence;

S1025: Determine the average value of each element in the filtered first sequence, and use the average value as the duty cycle of the driving signal of the buck circuit.

In one of the embodiments of the present invention, the duty ratio of the driving signal of the buck circuit can be obtained directly by using the duty ratio of the control loop. Because the control process of the control loop is very fine, and the duty cycle changes in real time, in order to improve the accuracy, the embodiment of the present invention collects multiple duty cycles within a preset period, and uses the filtered average value as the driving signal of the buck circuit Duty cycle, high precision and easy acquisition.

In some embodiments, before S1021, S102 may further include:

S1026: According to the input voltage and the output voltage, the duty ratio of the driving signal of the BUCK circuit is calculated by the second formula;

The second formula can be:

Among them, D is the duty cycle of the drive signal, L is the inductance value of the buck circuit, U _in is the input voltage, U ₀ is the output voltage, I _r0 is the rated output current, and T is the drive signal period.

In the embodiment of the present invention, the duty ratio of the driving signal of the buck circuit can also be directly determined according to the input voltage and the output voltage, without obtaining the duty ratio of the control loop.

BUCK电路恒流充电，由公式(5)，实际输出电流

结合公式(2)和公式(5)可以得到：Referring to Figure 1 and Figure 2, from the formula (2), the peak current flowing through the energy storage inductor

BUCK circuit constant current charging, by formula (5), the actual output current

Combining formula (2) and formula (5), we can get:

The constant current charging of the BUCK circuit can be obtained from formula (9):

Based on the above, in the embodiment of the present invention, when the input voltage and/or the output voltage changes, the duty cycle of the driving signal changes, and D in the current compensation coefficient calculation formula also changes accordingly.

Further, in case of constant current charging, it can be obtained from formula (8) and formula (1), and the calculation formula of the current compensation coefficient can be:

In the embodiment of the present invention, the current compensation coefficient can also be determined only according to the input voltage and the output voltage, without obtaining the duty cycle of the driving signal, and the calculation process is simpler.

It should be understood that the size of the sequence numbers of the steps in the above embodiments does not mean the sequence of execution, and the execution sequence of each process should be determined by its functions and internal logic, and should not constitute any limitation to the implementation process of the embodiments of the present invention.

Referring to FIG. 4 , corresponding to the above-mentioned embodiment, an embodiment of the present invention further provides a current calibration device of a buck circuit, and the buck circuit works in a DCM mode; the above-mentioned device includes:

The voltage acquisition module 21 is used to acquire the input voltage and output voltage of the buck circuit;

The compensation coefficient determination module 22 is used for determining the current compensation coefficient according to the input voltage and the output voltage;

The current calibration module 23 is used for calibrating the sampled output current of the buck circuit according to the current compensation coefficient to obtain the target output current.

In some embodiments, the compensation coefficient determination module 22 may include:

The duty ratio obtaining unit 221 is used to obtain the duty ratio of the driving signal of the BUCK circuit;

The compensation coefficient output unit 222 is configured to determine the current compensation coefficient according to the duty cycle of the driving signal, the input voltage and the output voltage.

In some embodiments, the compensation coefficient output unit 222 is specifically configured to:

According to the duty cycle of the driving signal, the input voltage and the output voltage, the current compensation coefficient is calculated by the first formula;

The first formula can be:

Among them, D is the duty cycle of the drive signal, U _in is the input voltage, and U ₀ is the output voltage.

In some embodiments, the current calibration module 23 may include:

The calibration unit 231 is configured to multiply the sampled output current of the buck circuit by the current compensation coefficient to obtain the target output current.

In some embodiments, the compensation coefficient determination module 22 may further include:

The first sequence obtaining unit 223 is used to obtain the duty ratios of the control loops of multiple BUCK circuits within a preset time period to form a first sequence;

Filtering unit 224, configured to filter the first sequence to obtain the filtered first sequence;

The first result output unit 225 is configured to determine the average value of each element in the filtered first sequence, and use the average value as the duty cycle of the driving signal of the BUCK circuit.

In some embodiments, the compensation coefficient determination module 22 may further include:

The second result output unit 226 is used to obtain the duty ratio of the driving signal of the buck circuit by calculating the second formula according to the input voltage and the output voltage;

The second formula can be:

Among them, D is the duty cycle of the drive signal, L is the inductance value of the buck circuit, U _in is the input voltage, U ₀ is the output voltage, I _r0 is the rated output current, and T is the drive signal period.

Those skilled in the art can clearly understand that, for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example. The module is completed, that is, the internal structure of the calibration device is divided into different functional units or modules, so as to complete all or part of the functions described above. Each functional unit and module in the embodiment may be integrated in one processing unit, or each unit may exist physically alone, or two or more units may be integrated in one unit, and the above-mentioned integrated units may adopt hardware. It can also be realized in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing from each other, and are not used to limit the protection scope of the present application. For the specific working process of the units and modules in the above apparatus, reference may be made to the corresponding processes in the foregoing method embodiments, and details are not described herein again.

FIG. 5 is a schematic block diagram of a calibration device provided by an embodiment of the present invention. As shown in FIG. 5 , the calibration apparatus 4 of this embodiment includes: one or more processors 40 , a memory 41 , and a computer program 42 stored in the memory 41 and executable on the processor 40 . When the processor 40 executes the computer program 42 , the steps in the above-mentioned embodiments of the current calibration method for each buck circuit are implemented, for example, steps S101 to S103 shown in FIG. 3 . Alternatively, when the processor 40 executes the computer program 42 , the functions of each module/unit in the above-mentioned embodiment of the current calibration apparatus of the buck circuit are implemented, for example, the functions of the modules 21 to 23 shown in FIG. 4 .

Illustratively, the computer program 42 may be divided into one or more modules/units, which are stored in the memory 41 and executed by the processor 40 to complete the present application. One or more modules/units may be a series of computer program instruction segments capable of performing specific functions, the instruction segments being used to describe the execution of the computer program 42 in the calibration device 4 . For example, the computer program 42 may be divided into a voltage acquisition module 21 , a compensation coefficient determination module 22 and a current calibration module 23 .

The voltage acquisition module 21 is used to acquire the input voltage and output voltage of the buck circuit;

The compensation coefficient determination module 22 is used for determining the current compensation coefficient according to the input voltage and the output voltage;

The current calibration module 23 is used for calibrating the sampled output current of the buck circuit according to the current compensation coefficient to obtain the target output current.

Other modules or units will not be described in detail here.

The calibration device 4 includes but is not limited to the processor 40 and the memory 41 . Those skilled in the art can understand that FIG. 5 is only an example of the calibration device, and does not constitute a limitation on the calibration device 4, and may include more or less components than the one shown, or combine some components, or different components For example, the calibration device 4 may also include an input device, an output device, a network access device, a bus, and the like.

The processor 40 may be a central processing unit (Central Processing Unit, CPU), other general-purpose processors, a digital signal processor (Digital Signal Processor, DSP), an application specific integrated circuit (Application Specific Integrated Circuit, ASIC), a field-available processor Field-Programmable Gate Array (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like.

The memory 41 may be an internal storage unit of the calibration device, such as a hard disk or memory of the calibration device. The memory 41 can also be an external storage device of the calibration device, such as a plug-in hard disk equipped on the calibration device, a smart memory card (Smart Media Card, SMC), a secure digital (Secure Digital, SD) card, a flash memory card (Flash Card) Wait. Further, the memory 41 may also include both an internal storage unit of the calibration device and an external storage device. The memory 41 is used to store the computer program 42 and other programs and data required to calibrate the device. The memory 41 may also be used to temporarily store data that has been output or is to be output.

In the foregoing embodiments, the description of each embodiment has its own emphasis. For parts that are not described or described in detail in a certain embodiment, reference may be made to the relevant descriptions of other embodiments.

Those of ordinary skill in the art can realize that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Skilled artisans may implement the described functionality using different methods for each particular application, but such implementations should not be considered beyond the scope of this application.

In the embodiments provided in this application, it should be understood that the disclosed calibration apparatus and method may be implemented in other ways. For example, the above-described calibration device embodiments are only illustrative. For example, the division of modules or units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components may be combined. Either it can be integrated into another system, or some features can be omitted, or not implemented. On the other hand, the shown or discussed mutual coupling or direct coupling or communication connection may be through some interfaces, indirect coupling or communication connection of devices or units, and may be in electrical, mechanical or other forms.

Units described as separate components may or may not be physically separated, and components shown as units may or may not be physical units, that is, may be located in one place, or may be distributed to multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution in this embodiment.

In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically alone, or two or more units may be integrated into one unit. The above-mentioned integrated units may be implemented in the form of hardware, or may be implemented in the form of software functional units.

The integrated modules/units, if implemented in the form of software functional units and sold or used as stand-alone products, may be stored in a computer-readable storage medium. Based on this understanding, the present application realizes all or part of the processes in the methods of the above embodiments, and can also be completed by instructing relevant hardware through a computer program, and the computer program can be stored in a computer-readable storage medium, and the computer program is in When executed by a processor, the steps of each of the above method embodiments can be implemented. Wherein, the computer program includes computer program code, and the computer program code may be in the form of source code, object code, executable file or some intermediate forms, and the like. The computer-readable medium may include: any entity or device capable of carrying computer program code, recording medium, U disk, removable hard disk, magnetic disk, optical disk, computer memory, Read-Only Memory (ROM), random access memory Memory (Random Access Memory, RAM), electric carrier signal, telecommunication signal, software distribution medium, etc. It should be noted that the content contained in computer-readable media may be appropriately increased or decreased in accordance with the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, computer-readable media does not include It is an electrical carrier signal and a telecommunication signal.

The above embodiments are only used to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: The recorded technical solutions are modified, or some technical features thereof are equivalently replaced; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the application, and should be included in the application. within the scope of protection.

Claims (10)

1. A current calibration method of a BUCK circuit is characterized in that the BUCK circuit works in a DCM mode; the method comprises the following steps:

acquiring input voltage and output voltage of the BUCK circuit;

determining a current compensation coefficient according to the input voltage and the output voltage;

and calibrating the output current of the BUCK circuit obtained by sampling according to the current compensation coefficient to obtain a target output current.

2. The method for calibrating current of BUCK circuit of claim 1, wherein said determining a current compensation factor based on said input voltage and said output voltage comprises:

acquiring the duty ratio of a driving signal of the BUCK circuit;

and determining the current compensation coefficient according to the duty ratio of the driving signal, the input voltage and the output voltage.

3. The method for calibrating current of a BUCK circuit according to claim 2, wherein said determining the current compensation factor according to the duty cycle of the driving signal, the input voltage and the output voltage comprises:

calculating the current compensation coefficient according to the duty ratio of the driving signal, the input voltage and the output voltage by a first formula;

the first formula is:

wherein D is the duty ratio of the driving signal, U_inFor said input voltage, U₀Is the output voltage.

4. The method for calibrating current of the BUCK circuit according to claim 3, wherein the calibrating the sampled output current of the BUCK circuit according to the current compensation coefficient to obtain a target output current comprises:

and multiplying the sampled output current of the BUCK circuit by the current compensation coefficient to obtain the target output current.

5. The method for current calibration of a BUCK circuit according to any of claims 2 to 4, wherein before said obtaining the duty cycle of the driving signal of the BUCK circuit, the method further comprises:

obtaining duty ratios of control loops of the BUCK circuits within a preset time period to form a first sequence;

filtering the first sequence to obtain a filtered first sequence;

and determining an average value of each element in the filtered first sequence, and taking the average value as the duty ratio of the drive signal of the BUCK circuit.

6. The method for current calibration of a BUCK circuit according to any of claims 2 to 4, wherein before said obtaining the duty cycle of the driving signal of the BUCK circuit, the method further comprises:

calculating the duty ratio of a driving signal of the BUCK circuit according to the input voltage and the output voltage by a second formula;

the second formula is:

wherein D is the duty ratio of the driving signal, L is the inductance value of the BUCK circuit, and U is_inFor said input voltage, U₀For the output voltage, I_r0For rated output current, T is the drive signal period.

7. The method for calibrating current of BUCK circuit according to claim 1, wherein the sampled output current of BUCK circuit is the sampled output current of BUCK circuit at the midpoint;

the midpoint sampling is to sample at the middle moment of the conduction period of the switching tube of the BUCK circuit in each driving signal period.

8. A current calibration device of a BUCK circuit is characterized in that the BUCK circuit works in a DCM mode; the above-mentioned device includes:

the voltage acquisition module is used for acquiring the input voltage and the output voltage of the BUCK circuit;

the compensation coefficient determining module is used for determining a current compensation coefficient according to the input voltage and the output voltage;

and the current calibration module is used for calibrating the sampled output current of the BUCK circuit according to the current compensation coefficient to obtain a target output current.

9. Calibration device comprising a memory, a processor and a computer program stored in said memory and executable on said processor, characterized in that said processor, when executing said computer program, implements the steps of the current calibration method of the BUCK circuit according to any of the claims 1 to 7.

10. A computer-readable storage medium, storing a computer program, wherein the computer program, when executed by a processor, implements the steps of the current calibration method of the BUCK circuit according to any of claims 1 to 7.

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