Current limiting control circuit and control method thereof

Abstract

The embodiment of the invention discloses a current-limiting control circuit and a control method thereof, and relates to the technical field of switching power supplies, the current-limiting control circuit comprises a signal sampling module, a signal processing module, a comparison module, a driving module, an isolation feedback module and an electric energy conversion module; the output end of the signal sampling module is connected with the input end of the signal processing module; the output end of the signal processing module is connected with the input end of the comparison module; the output end of the comparison module is connected with the first input end of the driving module, and the second input end of the driving module is used for accessing a preset reference voltage; the output end of the driving module is connected with the input end of the isolation feedback module; the output end of the isolation feedback module is connected with the input end of the electric energy conversion module; the output end of the electric energy conversion module is used for being connected with multiple paths of loads. Multi-port total current limiting can be met, single-port current limiting can also be achieved, stable power distribution and performance guarantee are achieved, and system reliability is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of switching power supply, in particular to a current limiting control circuit and a control method thereof. BACKGROUND

[0002] In recent years, with the development of USB fast charging technology, multi-port charging devices represented by mobile power supply and power strip have emerged to meet the demand for simultaneous charging of multiple devices, providing great convenience for users. The traditional technology adopts total multi-port current limiting, but this may have the risk of single-port high power, resulting in device overcurrent, overheating, and even device damage. SUMMARY

[0003] The technical problem to be solved by the embodiments of the present application is that the total multi-port current limiting has the risk of single-port high power, resulting in device overcurrent, overheating, and even device damage.

[0004] To solve the above problems, the embodiments of the present application disclose a current limiting control circuit and a control method thereof. The current limiting control circuit can not only meet the total multi-port current limiting but also realize single-port current limiting, realize stable power distribution and performance guarantee, and improve system reliability.

[0005] The present application provides a current limiting control circuit, which comprises a signal acquisition circuit and a driving feedback circuit; the input end of the signal acquisition circuit is connected to a plurality of load paths; the signal acquisition circuit comprises a maximum signal screening unit, which outputs a maximum target signal in the plurality of load paths to the driving feedback circuit; the driving feedback circuit is used to drive an electric energy output component based on the target signal output by the maximum signal screening unit.

[0006] Further, the signal acquisition circuit further comprises a plurality of current sampling units, each current sampling unit is connected to a load path, and is used to acquire a branch current signal of the corresponding load path and convert the branch current signal into a branch voltage signal.

[0007] Further, the signal acquisition circuit further comprises a summing unit, a coefficient adjusting unit and a maximum signal screening unit; the input end of the summing unit is connected to the output end of each current sampling unit, and is used to sum all branch voltage signals to obtain a total voltage signal corresponding to a total load current; the input end of the coefficient adjusting unit is connected to the output end of the summing unit, and the output end of the coefficient adjusting unit is connected to the input end of the maximum signal screening unit, and the coefficient adjusting unit is used to multiply each branch voltage signal and the total voltage signal by a coefficient respectively to output a branch target signal and a total target signal.

[0008] Further, the multiplication coefficient corresponding to the total target signal is smaller than the multiplication coefficient corresponding to each branch target signal.

[0009] Further, the multiplication coefficients corresponding to the branch target signals can be configured to be all equal or partially unequal.

[0010] Further, the driving feedback circuit comprises a comparison unit, a driving unit and an isolation feedback unit; the comparison unit comprises an operational amplifier, a first input end of the operational amplifier is connected with the signal acquisition circuit, a second input end of the operational amplifier is connected with a preset signal threshold, and the values of the first input end and the second input end are compared to output a comparison result; the input end of the driving unit is connected with the output end of the comparison unit, and a corresponding driving signal is output according to the comparison result; the input end of the isolation feedback unit is connected with the output end of the driving unit, and the output end of the isolation feedback unit is used as the output end of the driving feedback circuit to transmit the driving signal to the electric energy output component.

[0011] Further, the isolation feedback unit is an optical coupling element.

[0012] Further, the electric energy output component comprises a transformer, a primary side of the transformer is connected with the output end of the driving feedback circuit, and a secondary side is connected with the multiple load paths.

[0013] The application further provides a control method of the current-limiting control circuit, which comprises the following steps: acquiring target signals of the multiple load paths through the signal acquisition circuit; selecting the maximum target signal and outputting the same to the driving feedback circuit; driving the electric energy output component based on the maximum target signal.

[0014] Compared with the prior art, the application can achieve the following technical effects: The maximum target signal in the multiple load paths is selected through the signal acquisition circuit, and the electric energy output component is driven based on the maximum target signal through the driving feedback circuit, so that the double control of single-port current limiting and total-port current limiting is realized; by reasonably setting the multiplication coefficients of the total target signal and the branch target signal, the total current limiting threshold is ensured to be greater than the single-port current limiting threshold, and the current limiting conflict is avoided; by switching the current limiting mode and the voltage limiting mode, the power stable distribution during the charging of multiple devices is ensured, the overcurrent and overheating risks caused by single-port high-power output are effectively prevented, and the operation reliability and safety of the multiple power supply devices are significantly improved. BRIEF DESCRIPTION OF DRAWINGS

[0015] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is an application schematic diagram of a current limiting control circuit provided in an embodiment of the present invention; Figure 2 A schematic diagram of the current limiting control circuit provided in an embodiment of the present invention; Figure 3 A schematic diagram of a signal acquisition circuit provided in an embodiment of the present invention; Figure 4 This is a flowchart illustrating a control method for a fast charging chip cascade circuit provided in an embodiment of the present invention. Detailed Implementation

[0017] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Similar component reference numerals in the drawings represent similar components. Obviously, the embodiments described below are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0018] It should be understood that, when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0019] It should also be understood that the terminology used in this specification of embodiments of the invention is for the purpose of describing particular embodiments only and is not intended to limit the embodiments of the invention. As used in this specification of embodiments of the invention and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0020] See Figures 1-3This invention provides a current limiting control circuit. The current limiting control circuit includes a signal acquisition circuit and a drive feedback circuit; the input terminal of the signal acquisition circuit is connected to multiple load paths; the signal acquisition circuit includes a maximum signal filtering unit, which outputs the largest target signal among the multiple load paths to the drive feedback circuit; the drive feedback circuit is used to drive a power output component based on the target signal output by the maximum signal filtering unit. The specific details of each component are as follows: In this embodiment, the signal acquisition circuit is used to acquire current-related signals from multiple load paths and filters out the maximum target signal through a built-in maximum signal filtering unit; the drive feedback circuit is used to receive the maximum target signal output by the signal acquisition circuit, and sends drive commands to the power output component through signal processing and isolated transmission, and is the core execution module connecting signal acquisition and power regulation; the multiple load paths refer to the various independent power supply branches in a multi-port power supply device used to connect the charged device, and are the objects of current signal acquisition; the power output component is used to convert the input power into output power adapted to the load, and receives commands from the drive feedback circuit to adjust the output state, and is the execution terminal for implementing current limiting and voltage limiting.

[0021] Specifically, taking a multi-port charger with two load paths (path 0 and path 1) as an example, there is no specific limit to the number of paths in actual application scenarios. The input of the signal acquisition circuit is connected in series with the two load paths respectively, and the current-related signals of each path are acquired in real time. The maximum signal filtering unit built into the signal acquisition circuit continuously monitors and compares the target signals of the two load paths, filters out the current maximum target signal and transmits it to the drive feedback circuit. After receiving the maximum target signal, the drive feedback circuit processes the signal and generates a drive command, which is transmitted to the power output component (transformer). The transformer adjusts the power transmission efficiency according to the drive command to achieve current control of the corresponding path or the total load.

[0022] Breaking away from the traditional single control mode of total current limiting for multi-port devices, it achieves integrated management and control of current limiting for both single ports and total ports through maximum signal filtering and targeted drive control. The circuit structure is simple, the core components have clear division of labor, and the signal transmission path is clear, laying the foundation for subsequent expansion of refined current limiting for single ports and total ports. Compared with traditional solutions, it significantly improves the flexibility and targeting of current limiting control.

[0023] See also Figures 1-3 In this embodiment, the signal acquisition circuit further includes a multi-channel current sampling unit, each current sampling unit being connected to a corresponding load path to acquire the branch current signal of the corresponding load path and convert the branch current signal into a branch voltage signal.

[0024] In this embodiment, each current sampling unit corresponds to one load path and has a built-in sampling resistor and signal conversion element. It has dual functions of current acquisition and electrical signal conversion, and can convert non-electrical signal current information into branch voltage signals that are easy to process.

[0025] Specifically, based on the aforementioned multi-port charger, a current sampling unit is configured for each of the two load paths. Each current sampling unit includes a sampling resistor RCS and a signal conversion chip. When path 0 is connected to a mobile phone for charging, the sampling resistor RCS samples the branch current Iload0 of path 0, and the signal conversion chip converts this current signal into a branch voltage signal vcs_fb0 that is positively correlated with the current. In other words, when path 1 is connected to a tablet for charging, the corresponding current sampling unit outputs the branch voltage signal vcs_fb1, realizing the independent acquisition and conversion of the two current signals.

[0026] By configuring an independent current sampling unit for each load path, accurate acquisition and individual conversion of current signals from each branch are achieved, avoiding errors caused by mixed acquisition of multiple signals. The output format of the branch voltage signal facilitates subsequent signal processing operations such as summation and coefficient adjustment. Compared with the traditional method of centralized acquisition of total current, this improves the accuracy and relevance of signal acquisition.

[0027] Furthermore, the signal acquisition circuit also includes a summation unit, a coefficient adjustment unit, and a maximum signal filtering unit; the input terminal of the summation unit is connected to the output terminal of all the current sampling units, and is used to sum all branch voltage signals to obtain a total voltage signal corresponding to the total load current; the input terminal of the coefficient adjustment unit is connected to the output terminal of the summation unit, and the output terminal of the coefficient adjustment unit is connected to the input terminal of the maximum signal filtering unit, and is used to perform coefficient multiplication processing on each branch voltage signal and the total voltage signal respectively, and output the branch target signal and the total target signal.

[0028] In this embodiment, the summation unit is connected to the output of all current sampling units and is used to sum all branch voltage signals to generate a total voltage signal corresponding to the total load current of the multi-port, providing a signal basis for total port current limiting. The input of the coefficient adjustment unit is connected to the output of the current sampling unit and the output of the summation unit, respectively. Different multiplication coefficients can be applied to the branch voltage signal and the total voltage signal to output the branch target signal and the total target signal, realizing flexible configuration of the current limiting threshold. The input of the maximum signal filtering unit is connected to the output of the coefficient adjustment unit. Using a maximum voltage comparator, it can filter out the maximum signal from all branch target signals and the total target signal, providing the core control signal for the drive feedback circuit.

[0029] Specifically, the summation unit uses an addition circuit, such as an adder, to receive vcs_fb0 and vcs_fb1, perform summation processing, and output the total voltage signal vcs_fbt = vcs_fb0 + vcs_fb1. The coefficient adjustment unit has two branch coefficient channels and one total coefficient channel built in, such as a multiplier, with branch coefficients k0 = k1 = 1.2 and total coefficient kt = 0.8. It performs multiplication processing on vcs_fb0, vcs_fb1, and vcs_fbt respectively, and outputs branch target signals vcs_cc0 = 1.2vcs_fb0, vcs_cc1 = 1.2vcs_fb1, and total target signal vcs_cct = 0.8 * vcs_fbt.

[0030] In one embodiment, the maximum signal filtering unit includes a cascaded voltage comparator structure. For example, the two inputs of the first-stage comparator are connected to vcs_cc0 and vcs_cc1 respectively, and the larger value v_max1 of the two signals is output. The two inputs of the second-stage comparator are connected to v_max1 and vcs_cct respectively, and the final maximum target signal vfb_cc is output, thereby realizing the maximum value filtering of the three signals (2 branch signals + 1 total signal).

[0031] If the number of load paths increases (e.g., m paths), it can be achieved by increasing the number of comparator cascade stages. Each comparator stage filters two signals, and finally outputs the maximum value of all signals. It should be noted that the maximum signal filtering unit, including the voltage comparator cascade structure, is only an example. Those skilled in the art can also use multi-channel comparator chips to replace the cascade structure, and directly filter the maximum signal through the multi-channel comparison logic inside the chip, simplifying the circuit layout and improving the integration. The core is "to filter the maximum value from the target signals of multiple branches and the total target signal through multi-level comparison or integration logic", which does not exceed the protection scope of this invention.

[0032] By combining the summation unit, coefficient adjustment unit, and maximum signal filtering unit, synchronous processing and priority judgment of branch signals and total signals are achieved, solving the technical problem that traditional solutions cannot simultaneously handle single-port and total port current limiting. Each unit has a clear division of labor and clear signal processing logic, providing flexible configuration space for subsequent coefficient optimization and threshold adjustment, and improving the adaptability of the circuit.

[0033] Furthermore, the multiplication coefficient corresponding to the total target signal is less than the multiplication coefficient corresponding to the target signals of each branch.

[0034] Specifically, the branch coefficients k0=k1=1.2, the total coefficients kt=0.8, and kt<k(m) are satisfied; the sampling coefficients a0=0.1V / A (determined by the sampling resistor) are known, and the preset signal threshold vref_cc=0.36V. When the current Iload0 = 3A in the zero-path current, vcs_fb0 = 0.1 * 3 = 0.3V and vcs_cc0 = 1.2 * 0.3 = 0.36V, reaching the signal threshold. At this time, the total current Iloadt = 3A + 0.5A = 3.5A, vcs_fbt = 0.1 * 3.5 = 0.35V and vcs_cct = 0.8 * 0.35 = 0.28V < 0.36V, ensuring that single-port current limiting is triggered first. When both currents are 2.5A, the total current Iloadt = 5A, vcs_fbt = 0.5V and vcs_cct = 0.8 * 0.5 = 0.4V > 0.36V, triggering total current limiting.

[0035] By setting kt < k(m), the priority of single-port current limiting and total port current limiting is clarified, ensuring that single-port current limiting is triggered first when the single-port current is close to the threshold, thus avoiding high power output from a single port; total port current limiting is only triggered when all single-port currents are below their own thresholds but the total current is close to the threshold, thus achieving orderly coordination between single-port and total port current limiting, avoiding current limiting conflicts, and improving the rationality of power allocation.

[0036] Furthermore, the multiplication coefficients corresponding to the target signals of each branch can be configured to be all equal or partially unequal.

[0037] In this embodiment, the configuration of the multiplication coefficients (k(m)) corresponding to the target signals of each branch can be flexibly set to be all equal or partially unequal according to the actual application scenario, to adapt to the current limiting requirements of different ports.

[0038] Specifically, in scenario 1 (equal coefficients): both ports of the multi-port charger support a maximum current limit of 3A. With k0=k1=1.2, combined with a0=0.1V / A and vref_cc=0.36V, the current limit threshold for both ports is 3A, meeting the same current limit requirement. In scenario 2 (unequal coefficients): port 0 of the charger supports a current limit of 3A, and port 1 supports a current limit of 2A. With k0=1.2 and k1=1.8, combined with the same a0 and vref_cc, the current limit threshold for port 0 is 3A, and the current limit threshold for port 1 is 2A, adapting to the charging needs of different power loads.

[0039] This configuration method enhances the adaptability of the circuit, allowing for differentiated current limiting thresholds based on the port function of multi-port devices (such as fast charging ports and regular charging ports). It can adapt to various product requirements without changing the circuit structure, reducing product development and iteration costs.

[0040] Furthermore, the drive feedback circuit includes a comparison unit, a drive unit, and an isolation feedback unit; the comparison unit includes an operational amplifier, the first input terminal of which is connected to the signal acquisition circuit, and the second input terminal of which is connected to a preset signal threshold, for comparing the values ​​of the first input terminal and the second input terminal and outputting a comparison result; the input terminal of the drive unit is connected to the output terminal of the comparison unit, for outputting a corresponding drive signal according to the comparison result; the input terminal of the isolation feedback unit is connected to the output terminal of the drive unit, and the output terminal of the isolation feedback unit serves as the output terminal of the drive feedback circuit, for transmitting the drive signal to the power output component.

[0041] In this embodiment, the comparison unit uses an operational amplifier. The first input terminal receives the maximum target signal, and the second input terminal is connected to a preset signal threshold. It outputs the comparison result by comparison and is a key component for realizing mode switching. The driving unit is used to receive the comparison result of the comparison unit and convert it into a driving signal adapted to the isolation feedback unit. It has signal amplification and format conversion functions. The isolation feedback unit realizes isolated signal transmission, avoids high voltage signal interference from the power output component to the control circuit, and transmits the driving signal to the power output component to ensure the safe and stable operation of the circuit.

[0042] Specifically, the comparison unit includes an operational amplifier GM1. The non-inverting input (first input) of the operational amplifier is connected to the output of the maximum signal filtering unit of the signal acquisition circuit, and the inverting input (second input) of the operational amplifier is connected to a preset signal threshold vref_cc = 0.36V. For example, when the maximum target signal vfb_cc = 0.4V > 0.36V, the operational amplifier outputs a high-level comparison result. The driving unit includes a MOSFET M1, which outputs a driving current to the isolation feedback unit (optocoupler D2) after receiving a high-level signal. After receiving the driving current, the optocoupler turns on and transmits the isolated driving signal to the primary side of the transformer, triggering the current limiting mode.

[0043] By working together with the operational amplifier, driver unit and isolation feedback unit, the integrated processing of signal comparison, drive amplification and isolation transmission is realized, which solves the problems of signal interference and insufficient drive capability in traditional solutions; the isolation feedback design ensures electrical isolation between the control circuit and the high-voltage power output components, and improves the safety and stability of circuit operation.

[0044] Furthermore, the isolation feedback unit is an optocoupler.

[0045] Specifically, optocouplers have electrical isolation characteristics, which can block the current conduction between the power output component and the control circuit while transmitting drive signals, thus avoiding high voltage interference.

[0046] Furthermore, the power output component includes a transformer, the primary side of which is connected to the output terminal of the drive feedback circuit, and the secondary side is correspondingly connected to multiple load paths.

[0047] Specifically, the transformer adopts a flyback transformer. The primary winding is connected to the output terminal of the optocoupler, and the secondary winding is divided into two paths, which are respectively connected to the two load paths. When the optocoupler transmits the current limiting drive signal, the primary side of the transformer adjusts the excitation current to reduce the power output of the secondary side, so that the current of the corresponding load path is reduced to below the threshold. When the voltage limiting drive signal is transmitted, the primary side of the transformer maintains a stable excitation state to ensure that the secondary output voltage is stable.

[0048] As the core of power conversion, the transformer, in conjunction with the instructions of the drive feedback circuit, achieves precise regulation of power output. Compared with the traditional passive current limiting scheme, the active adjustment of power transmission efficiency has a faster response speed, higher current limiting and voltage limiting accuracy, and adapts to the branch distribution requirements of multi-port power supply, ensuring output stability when multiple devices are charging at the same time.

[0049] See Figure 1 , Figure 1 This is a schematic diagram of a current limiting control circuit provided in an embodiment of the present invention. The schematic diagram is analyzed as follows: The current limiting control circuit is powered by VIN. The isolation optocoupler D2 is connected to the current limiting control circuit through the OPTO port. It samples the load current Iload or the sampling voltage VIN information in the load path of each port (0 to m, m≥1, where m is related to the application requirements) through the sampling resistor RCS. After processing by the current limiting control circuit, the OPTO voltage is changed, which actually changes the current flowing through the optocoupler D2. The current is then fed back to the primary side of the transformer T0 through the optocoupler isolation, realizing feedback regulation and thus achieving stable output of the entire system.

[0050] See Figure 2 , Figure 2 The schematic diagram of the current limiting control circuit provided in the embodiment of the present invention is as follows: The signal acquisition circuit obtains the current information of each load port through external pins CSP0, CSN0 to CSPm, CSNm, and outputs a sampling voltage signal vfb_cc that is positively correlated with the load current. vfb_cc and the reference voltage vref_cc are input to the positive and negative input terminals of operational amplifier GM1, respectively. The output voltage gate_cc controls the current flowing through MOSFET M1, and thus controls the current flowing through optocoupler D2. Specifically, as the load current increases, vfb_cc increases. When vfb_cc is greater than vref_cc, the voltage gate_cc increases, controlling the current flowing through MOSFET M1 to increase. At this time, the system switches from CV module (constant voltage mode) to CC mode (constant current mode). After entering CC mode, the current flowing through optocoupler D2 will not change. If the load continues to increase, the output voltage will decrease.

[0051] See Figure 3 , Figure 3 The schematic diagram of the signal acquisition circuit provided in the embodiment of the present invention is as follows: The current sampling unit obtains a voltage signal that is positively correlated with the load current through the sampling port, as shown in Equation 1 below: vcs_fb(m) = a0 * Iload(m); Where a0 is the sampling multiple (a0 can be configured to different values ​​depending on the actual application, and this value cannot be used as a condition limiting this patent), and Iload(m) is the load current; The vcs_fb(m) signals output from each current sampling unit are input to the adder. After summation, the output is a voltage signal vcs_fbt that is positively correlated with the total load current, as shown in Equation 2 below: ; The individual sampled signals vcs_fb(m) and the sum of the sampled signals vcs_fbt are input into their respective multipliers and multiplied by coefficients k(m) and kt, respectively. The coefficients k(m) can be equal (k0 = k1 = ... = km) or unequal (k0 ≠ k1 ≠ ... ≠ km), depending on the application. The coefficient kt is typically kt. <k(m)); The output voltage signal vcs_cc(m) of each multiplier is given by the following formula (Equation 3): vcs_cc(m)=k(m)*vcs_fb(m)=k(m)*a0*Iload(m); The output voltage signal vcs_cct of each multiplier is given by the following formula (Equation 4): ; The multiplier can be designed with different current limiting values for different application designs, and the same or different coefficients can be selected; the voltage signals vcs_cc(m) and vcs_cct output by the multiplier are input into the maximum signal screening unit, and the maximum voltage signal vfb_cc is selected through comparison and input into the operational amplifier GM1 for comparison with the current limiting reference vref_cc (the reference vref_cc is the preset load current limiting value).

[0052] Since the current sampling unit can provide real-time feedback of the actual load information, when the load current of a certain port is large, for example, at this time the sampling signal vcs_cc1 of port 1 > vcs_cct, then vfb_cc = vcs_cc1, and the system will select vcs_cc1 for current limiting, that is, when k1*a0*Iload1 = vref_cc,, then the current of port 1 will be limited at this time; for another example, at this time vcs_cct > vcs_cc(m), then vfb_cc = vcs_cct, and the system will select vcs_cct for current limiting. By the same analysis, therefore, the total load current at this time, because kt < k(m), so the total current limiting value for multiple ports will be larger than the load current value of single-port current limiting; in summary, the system has completed single-port current limiting and total current limiting for multiple ports, achieving stable power distribution and performance guarantee.

[0053] See Figure 4 , the present invention also provides a control method for the current limiting control circuit as described in any one of the above embodiments. The control method of the current limiting control circuit includes steps S101 - S103: S101, collecting target signals of multiple load paths through a signal acquisition circuit.

[0054] S102, screening out the maximum target signal and outputting it to the drive feedback circuit.

[0055] S103, driving the power output component based on the maximum target signal.

[0056] In a specific embodiment, a multi-port charger is connected to two mobile phones (connected to path 0 and path 1 respectively). The specific implementation of this control method is as follows: First step, the signal acquisition circuit respectively collects the current Iload0 = 2.8A of path 0 and the current Iload1 = 2.2A of path 1 through two current sampling units, and after conversion into branch voltage signals and processing, generates target signals vcs_cc0 = 0.336V, vcs_cc1 = 0.264V, vcs_cct = 0.32V; Second step, the maximum signal screening unit screens out the maximum target signal vcs_cc0 = 0.336V and outputs it to the drive feedback circuit; Third step, the drive feedback circuit drives the transformer to adjust the power output based on this maximum target signal to maintain the current stable.

[0057] Based on the maximum target signal as the core control basis, a unified management and control logic for current limiting of single ports and total ports is realized. Compared with traditional multi-step complex control methods, the response speed is faster, the control logic is more intuitive, and it is easier to implement and debug in engineering. At the same time, it provides a clear logical framework for subsequent mode switching and coefficient optimization.

[0058] Further, step S101 above includes: converting the current signals of each branch into branch voltage signals, summing all the branch voltage signals to obtain the total voltage signal, and performing coefficient multiplication on the branch voltage signals and the total voltage signal respectively to obtain the branch target signal and the total target signal.

[0059] Specifically, firstly, the current sampling unit converts Iload0=2.8A of path 0 into vcs_fb0=0.28V, and Iload1=2.2A of path 1 into vcs_fb1=0.22V; secondly, the summing unit sums the voltage signals of the two branches to obtain vcs_fbt=0.28V+0.22V=0.5V; finally, the coefficient adjustment unit multiplies vcs_fb0 and vcs_fb1 by k0=k1=1.2 respectively to obtain vcs_cc0=0.336V and vcs_cc1=0.264V, and multiplies vcs_fbt by kt=0.8 to obtain vcs_cct=0.4V, thus completing the generation of the target signal.

[0060] By clearly defining the generation process of the target signal, the standardization and accuracy of signal processing are ensured. The function of each sub-step is clearly defined, making it easy to implement through hardware circuits or software algorithms. Compared with traditional fuzzy signal processing methods, this refined process improves the repeatability and operability of the method and reduces the problem of insufficient current limiting accuracy caused by signal processing errors.

[0061] Further, step S103 includes: if the maximum target signal is greater than a preset threshold, then drive the power output component to execute the current limiting mode of the corresponding load path or total load.

[0062] Specifically, the preset signal threshold is vref_cc=0.36V. When a high-power device is connected to channel 0, Iload0=3.2A. After signal processing, vcs_cc0=1.2*0.1*3.2=0.384V>0.36V. The comparator unit of the drive feedback circuit outputs a high level, and the drive unit generates a drive signal, which is transmitted to the transformer through the optocoupler. The transformer adjusts the primary side power transmission efficiency, reduces the secondary side output voltage of channel 0, and reduces Iload0 to 3A (corresponding to vcs_cc0=0.36V), thus achieving single-port current limiting.

[0063] The triggering conditions and execution logic of the current limiting mode are clearly defined. Compared with the traditional current limiting scheme without a clear trigger threshold, the current limiting response of this method is more accurate, avoiding the problem of reduced charging efficiency or equipment damage caused by limiting the current too early or too late, and ensuring the reliability and effectiveness of current limiting control.

[0064] Furthermore, step S103 above also includes: if the maximum target signal is not greater than a preset threshold, then drive the power output component to execute a voltage limiting mode.

[0065] Specifically, with a preset signal threshold of vref_cc=0.36V, when the two load paths are connected to a regular mobile phone, Iload0=1.5A and Iload1=1.2A respectively, the maximum target signal vcs_cc0=1.20.11.5=0.18V≤0.36V after signal processing. The comparator unit of the drive feedback circuit outputs a low level, and the drive unit generates a stable voltage-limiting drive signal, which is transmitted to the transformer via an optocoupler. The transformer maintains the primary side power transmission efficiency and outputs a stable 5V voltage on the secondary side to meet the normal charging requirements of the mobile phone.

[0066] By dynamically switching between current limiting mode and voltage limiting mode, the dual control objectives of "stabilizing voltage during normal charging and stabilizing current when current exceeds the limit" are achieved. Compared with the traditional single-mode power supply solution, it not only ensures charging efficiency but also takes into account safety protection, improving the user charging experience and the service life of the equipment.

[0067] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0068] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0069] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0070] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. The illustrative expressions of the above terms in this specification should not be construed as necessarily referring to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. In addition, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.

[0071] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Since these modifications and variations fall within the scope of the claims and their equivalents, this invention also intends to include these modifications and variations.

[0072] The above description describes specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A current limit control circuit, characterized by, The signal acquisition circuit comprises a signal acquisition circuit and a driving feedback circuit. An input end of the signal acquisition circuit is connected with a plurality of load paths. The signal acquisition circuit comprises a maximum signal screening unit, which outputs a maximum target signal in the plurality of load paths to the driving feedback circuit. The driving feedback circuit is used for driving an electric energy output component based on the target signal output by the maximum signal screening unit.

2. The current limit control circuit of claim 1, wherein, The signal acquisition circuit further comprises a plurality of current sampling units, each current sampling unit being connected with a load path, and being used for collecting a branch current signal of the corresponding load path and converting the branch current signal into a branch voltage signal.

3. The current limit control circuit of claim 2, wherein, The signal acquisition circuit further comprises a summing unit and a coefficient adjusting unit. An input end of the summing unit is connected with output ends of all the current sampling units, and the summing unit is used for summing all the branch voltage signals to obtain a total voltage signal corresponding to a total load current. An input end of the coefficient adjusting unit is connected with an output end of the summing unit, and an output end of the coefficient adjusting unit is connected with an input end of the maximum signal screening unit, and the coefficient adjusting unit is used for performing coefficient multiplication processing on each branch voltage signal and the total voltage signal to output a branch target signal and a total target signal.

4. The current limit control circuit of claim 3, wherein, A multiplication coefficient corresponding to the total target signal is smaller than multiplication coefficients corresponding to each branch target signal.

5. The current limit control circuit of claim 3, wherein, The multiplication coefficients corresponding to each branch target signal can be configured to be all equal or partially unequal.

6. The current limit control circuit of claim 1, wherein, The driving feedback circuit comprises a comparison unit, a driving unit and an isolation feedback unit. The comparison unit comprises an operational amplifier, a first input end of the operational amplifier being connected with the signal acquisition circuit, and a second input end of the operational amplifier being connected with a preset signal threshold, and the comparison unit is used for comparing values of the first input end and the second input end and outputting a comparison result. An input end of the driving unit is connected with an output end of the comparison unit, and the driving unit is used for outputting a corresponding driving signal according to the comparison result. An input end of the isolation feedback unit is connected with an output end of the driving unit, and an output end of the isolation feedback unit is used for transmitting the driving signal to the electric energy output component.

7. The current limit control circuit of claim 6, wherein, The isolation feedback unit is an optical coupling element.

8. The current limit control circuit of claim 1, wherein, The electric energy output component comprises a transformer, a primary side of the transformer being connected with the output end of the driving feedback circuit, and a secondary side of the transformer being connected with the plurality of load paths.

9. A control method of a current limit control circuit as claimed in any one of claims 1 to 8, characterized by, The method comprises the following steps. The signal acquisition circuit is used for collecting target signals of the plurality of load paths. The maximum target signal is screened out and output to the driving feedback circuit. The electric energy output component is driven based on the maximum target signal.

10. The control method of the current limit control circuit according to claim 9, wherein The step of collecting the target signals of the plurality of load paths by the signal acquisition circuit comprises the following steps. Each branch current signal is converted into a branch voltage signal, all the branch voltage signals are summed to obtain a total voltage signal, and coefficient multiplication processing is performed on each branch voltage signal and the total voltage signal to obtain a branch target signal and a total target signal.

11. The control method of the current limit control circuit according to claim 9, wherein The step of driving the electric energy output component based on the maximum target signal comprises the following steps. If the maximum target signal is greater than a preset threshold, the electric energy output component is driven to perform a current limiting mode for the corresponding load path or the total load.

12. The control method of the current limit control circuit according to claim 11, wherein The step of driving the electric energy output component based on the maximum target signal further comprises: if the maximum target signal is not greater than a preset threshold, driving the electric energy output component to execute a voltage limiting mode.

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