Current limiter, operation method thereof, and hot-swap module

Abstract

The present disclosure provides a current limiter, a method for operating the current limiter, and a hot-swap module including the current limiter. The current limiter includes: a current limiter module having an input terminal, an output terminal, and a control terminal, and configured to limit a current inputted via the input terminal thereof to a current limit range; and a range control module having a control terminal coupled to the control terminal of the current limiter module and a sense terminal coupled to the output terminal of the current limiter module, and configured to generate a control signal based on at least a current outputted via the output terminal of the current limiter module and sensed at the sense terminal, and output the control signal via the control terminal thereof, so that the current limit range is dynamically adjustable based on the control signal.

Description

Technical Field

[0001] The present disclosure relates to the field of electronic devices, and in particular to a current limiter and an operating method thereof, and a hot-swap module including the current limiter. Technical Background

[0002] High-availability systems, such as servers, network switches, redundant array of independent disks (RAID) storage devices, and other forms of communication infrastructure, need to be designed for near-zero downtime throughout their service life. If a component of such a system fails or needs to be updated, it must be replaced without disrupting the rest of the system. While the system remains operational, the board or component must be removed and its replacement inserted. This process is called hot swapping, or in some cases, hot replacement. To perform hot swapping safely, each printed circuit board (PCB) or plug-in component has an onboard hot swap module to facilitate the safe removal and insertion of the board from the live backplane.

[0003] A typical hot-swap technology is linear-mode hot-swap. This means the metal-oxide semiconductor field-effect transistor (MOSFET) in the hot-swap module operates in linear mode. In linear mode, the MOSFET acts as a resistor controlled by gate voltage. The higher the gate voltage, the lower the MOSFET's Rdson (i.e., on-resistance). By controlling the gate voltage, Rdson can be controlled to stay within a specified range.

[0004] Another hot-swap technology is switch-mode hot-swap. This means the MOSFET operates in a switching state. Switch-mode hot-swap operates similarly to a buck converter controlled by current hysteresis. Current is sensed at the output terminals of the inductor in the buck converter. When the current level exceeds the high limit of the current hysteresis, the switching MOSFET is turned off and the current is allowed to decrease. Once the current drops below the low limit of the current hysteresis, the switching MOSFET is turned back on. This way, inrush current is controlled.

[0005] However, the linear mode MOSFET must operate within the SOA (Safe Operating Area). The inrush current is small and is limited by the SOA, so the charging time will be long according to the following equation:

[0006] t=(C*V) / I,

[0007] Where t is the charging time, C is the output capacitance, V is the input voltage, and I is the inrush current. The larger the output capacitance, the longer the charging time (because I and V are fixed), and the wider the range of the charging MOSFET's SOA needs to be. Because the inrush current is much lower than the normal load current, after the charging process is complete, the charging MOSFET is often shorted by a low-resistance path (e.g., several fully-on MOSFETs), preventing the charging MOSFET from operating under normal load conditions. Therefore, the disadvantages of this circuit can be:

[0008] (1) The charging MOSFET SOA is a bottleneck, making it difficult to meet the requirements of larger output capacitance;

[0009] (2) The inrush current will be directly transferred from the input port to the holding capacitor, causing the holding voltage to be very high because the charging MOSFET is not functioning. The holding capacitor will be subjected to the high inrush voltage and may be damaged. In other words, the energy that passes through may easily damage the device.

[0010] On the other hand, although switch-mode hot-swap modules are not sensitive to output capacitance, the maximum inrush current is almost twice the maximum input current at full load. In this case, the high inrush current may cause the following problems:

[0011] (1) The PSU (power supply unit) OCP (overcurrent protection) may be easily triggered; and

[0012] (2) Severe power line LC resonance: Due to LC resonance, the MOSFET in the hot-swap module may be damaged during the power-on phase. Summary of the Invention

[0013] According to a first aspect of the present disclosure, a current limiter includes: a current limiting module, having an input terminal, an output terminal and a control terminal, and configured to limit a current input via its input terminal to a current limiting range; and a range control module, having a control terminal coupled to the control terminal of the current limiting module and a sensing terminal coupled to the output terminal of the current limiting module, and configured to generate a control signal based at least on a current output via the output terminal of the current limiting module and sensed at the sensing terminal, and output the control signal via its control terminal, so that the current limiting range is dynamically adjustable based on the control signal.

[0014] In some embodiments, the current limiting module includes: a switch having a first terminal serving as an input terminal of the current limiting module, a second terminal, and a control terminal serving as a control terminal of the current limiting module, and configured to be turned on or off in response to an on signal or an off signal input via the control terminal; an inductor having a first terminal coupled to the second terminal of the switch and a second terminal serving as an output terminal of the current limiting module; and a diode having a first terminal coupled to the second terminal of the switch and a second terminal connected to ground, wherein a forward direction of the diode is from the first terminal to the second terminal. In some embodiments, the switch is a metal oxide semiconductor field effect transistor (MOSFET), and the first terminal of the MOSFET is one of its source and drain, the second terminal of the MOSFET is the other of its source and drain, and the control terminal of the MOSFET is its gate. In some embodiments, the MOSFET is an N-type MOSFET, and the on signal is a high-level voltage signal, and the off signal is a low-level voltage signal.

[0015] In some embodiments, the current limiting module further includes a capacitor having a first terminal coupled to the second terminal of the inductor and a second terminal connected to ground.

[0016] In some embodiments, the range control module includes: a charge completion indication module having an input terminal and an output terminal, and configured to output a charge completion indication signal via the output terminal after a first preset time period has elapsed since a first trigger signal was received via the input terminal; a range selection module having an input terminal and an output terminal, the input terminal being coupled to the output terminal of the charge completion indication module, the range selection module being configured to initially output a first range selection signal via its output terminal, and to output a second range selection signal via its output terminal when the charge completion indication signal is received via its input terminal, the second range selection signal being associated with a current limit range different from the current limit range associated with the first range selection signal; a current sensing module having a first terminal and a second terminal, the first terminal serving as a sensing terminal of the range control module, the current sensing module being configured to sense a current at its first terminal and output a sensing signal indicative of the sensed current via its second terminal; and a switch driving module having a first terminal coupled to the output terminal of the range selection module, a second terminal coupled to the second terminal of the current sensing module, and a third terminal serving as a control terminal of the range control module, the switch driving module being configured to output a control signal based on the signals received at the first terminal and the second terminal.

[0017] In some embodiments, an input terminal of the charge completion indication module is coupled to a third terminal of the switch driving module, and the first trigger signal is the last on-signal input into the control terminal of the current limiting module, no off-signal is input into the control terminal of the current limiting module after the first trigger signal until expiration of a first preset time period, and the second preset time period is 10 ms.

[0018] In some embodiments, the charge completion indication signal is a high voltage signal, the first range selection signal is a low voltage signal, and the second range selection signal is a high voltage signal. In some embodiments, the sensing signal is a voltage signal having a level indicative of a current sensed at the first terminal of the current sensing module.

[0019] In some embodiments, the range selection module includes an OR gate having a first input terminal and a second input terminal serving as input terminals of the range selection module, and a third output terminal serving as an output terminal of the range selection module, wherein the OR gate is configured to perform a logical OR operation on inputs from the first input terminal and the second input terminal and output a signal indicating a result of the logical OR operation via the third output terminal; and an auxiliary power supply having a first terminal coupled to the third output terminal of the OR gate, a second terminal coupled to the output terminal of the current limit module, a third terminal coupled to ground, and a fourth terminal coupled to the second input terminal of the OR gate, wherein the auxiliary power supply is configured to output an auxiliary power ready (OK) signal via the fourth terminal after receiving an auxiliary power enable signal via the first terminal. In some embodiments, each of the auxiliary power ready signal and the auxiliary power enable signal is a high-level voltage signal.

[0020] In some embodiments, the switch driver module includes: a range signal processing module having an input terminal and an output terminal, the input terminal being coupled to the output terminal of the range selection module, and the range signal processing module being configured to output a reference signal via the output terminal, the reference signal being dynamically determined based on a signal received via the input terminal; and a comparator having a first input terminal coupled to the output terminal of the range signal processing module, a second input terminal coupled to the second terminal of the current sensing module, and an output terminal serving as a third terminal of the switch driver module, and being configured to output a control signal via the output terminal based on a comparison of the reference signal and the sense signal received via the first and second input terminals, respectively. In some embodiments, the range control module further includes an enable terminal, wherein the current limiter further includes a voltage protection module having a first terminal coupled to the input terminal of the current limit module, a second terminal coupled to ground, and a third terminal coupled to the enable terminal of the range control module, and the voltage protection module being configured to output an enable signal via the third terminal when a voltage detected across the first and second terminals is within a safe range. In some embodiments, the enable signal is a high-level voltage signal. In some embodiments, the switch driving module includes: a range signal processing module having an input terminal and an output terminal, the input terminal being coupled to the output terminal of the range selection module, and the range signal processing module being configured to output a reference signal via the output terminal, the reference signal being dynamically determined based on a signal received via the input terminal; a comparator having a first input terminal coupled to the output terminal of the range signal processing module, a second input terminal coupled to the second terminal of the current sensing module, and an output terminal, and the comparator being configured to output a control signal via the output terminal based on a comparison of the reference signal and the sensing signal received via the first input terminal and the second input terminal, respectively; and a switch driver having a first terminal coupled to the output terminal of the comparator, a second terminal serving as a third terminal of the switch driving module, and a third terminal serving as an enable terminal of the range control module, and the switch driver being configured to output the control signal only when the enable signal is received at its third terminal.

[0021] In some embodiments, the charge completion indication module further includes a disable terminal coupled to the enable terminal of the switch driver, and the charge completion indication module is further configured to output a disable signal via the disable terminal after a second preset time period has elapsed since the second trigger signal was received via the input terminal. In some embodiments, the disable signal is a low-level voltage signal that is capable of deactivating the enable signal output from the voltage protection module. In some embodiments, the input terminal of the charge completion indication module is coupled to a third terminal of the switch driver module, wherein the second trigger signal is a first conduction signal input to the control terminal of the current limiting module after the enable signal changes from a low-level voltage signal to a high-level voltage signal, and wherein the second preset time period is 250 milliseconds.

[0022] In some embodiments, the range signal processing module includes: a first transistor having a first terminal, a second terminal coupled to ground, and a control terminal serving as an input terminal of the range signal processing module; a second transistor having a first terminal, a second terminal coupled to ground, and a control terminal coupled to the first terminal of the first transistor; a first resistor having a first terminal coupled to a direct current (DC) power supply and a second terminal coupled to the first terminal of the first transistor; a second resistor (454) having a first terminal coupled to the first input terminal of the comparator and a second terminal coupled to the first terminal of the second transistor; a third resistor having a first terminal coupled to the first input terminal of the comparator and a second terminal coupled to ground; a fourth resistor having a first terminal coupled to the DC power supply and a second terminal coupled to the first input terminal of the comparator; and a fifth resistor having a first terminal coupled to the output terminal of the comparator and a second terminal coupled to the first input terminal of the comparator.

[0023] According to a second aspect, a hot-swap module for electronic equipment is provided, wherein the hot-swap module comprises the current limiter according to the first aspect of the present disclosure.

[0024] According to a third aspect, a method for operating the current limiter of the first aspect is provided. The method includes: in a first phase, inputting a first signal into the current limiter so that the first signal has a current level limited to a first current limit range; and in a second phase, after a first preset time period has elapsed since the first signal was received via an input terminal of the current limiter, inputting a second signal into the current limiter so that the second signal has a current level limited to a second current limit range, wherein the second current limit range is different from the first current limit range.

[0025] In some embodiments, the second current limit range has an upper limit and a lower limit that are higher than the upper limit and the lower limit of the first current limit range. In some embodiments, the method further includes: the voltage protection module, in response to an overvoltage event or an undervoltage event detected across the first terminal and the second terminal, outputs a disable signal via its third terminal, so that the switch is turned off. In some embodiments, the method further includes: the voltage protection module, in response to detecting the disappearance of the overvoltage event or the undervoltage event, outputs an enable signal via its third terminal, so that the switch is controlled only by the range control module. In some embodiments, the method further includes: the charge completion indication module, after a second preset time period has passed since the second trigger signal was received via its input terminal, outputs a disable signal via its disable terminal, so that the switch is turned off. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The foregoing and other features of the present disclosure will become more apparent from the following description and appended claims taken in conjunction with the accompanying drawings. Understanding that these drawings depict only several embodiments in accordance with the present disclosure and, therefore, should not be considered limiting of its scope, the present disclosure will be described with additional specificity and detail through use of the accompanying drawings.

[0027] Figure 1 is a block diagram illustrating an exemplary hot-swap enabling system according to an embodiment of the present disclosure.

[0028] Figure 2 is a block diagram illustrating an exemplary current limiter according to an embodiment of the present disclosure.

[0029] Figure 3 is a block diagram illustrating another exemplary current limiter according to an embodiment of the present disclosure.

[0030] Figure 4 is a block diagram illustrating yet another exemplary current limiter according to an embodiment of the present disclosure.

[0031] Figure 5 This is to show how to operate according to the embodiment of the present disclosure Figure 4 Timing diagram of the current limiter.

[0032] Figure 6 is a flow chart illustrating an exemplary method for operating a current limiter according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0033] Hereinafter, the present disclosure will be described with reference to the embodiments shown in the accompanying drawings. However, it should be understood that these descriptions are provided for illustrative purposes only and are not intended to limit the present disclosure. In addition, descriptions of known structures and technologies are omitted below to avoid unnecessary confusion of the concepts of the present disclosure.

[0034] Those skilled in the art will understand that the term "exemplary" is used herein to mean "illustrative" or "used as an example" and does not imply that a particular embodiment is preferred over another or that a particular feature is required. Similarly, the terms "first" and "second" and similar terms are used solely to distinguish one particular instance of an item or feature from another and do not imply a particular order or arrangement, unless the context clearly indicates otherwise. In addition, the term "step" as used herein is intended to be synonymous with "operation" or "action." Any description herein of a series of steps does not imply that those operations must be performed in a particular order, or even that all of those operations be performed in any order, unless the context or details of the operations being described clearly indicate otherwise.

[0035] The terms used herein are used only to describe specific embodiments and are not intended to limit the example embodiments. As used herein, the singular forms "a", "an", and "said" are also intended to include the plural forms, unless the context clearly dictates otherwise. It will be further understood that the terms "comprise", "compose", "have", "have", "contain" and / or "include", when used herein, specify the presence of the features, elements and / or components, etc., described, but do not exclude the presence or addition of one or more other features, elements, components and / or combinations thereof. It will also be understood that the terms "connect", "connected", and "connected" used herein only mean that there is an electrical or communication connection between two elements, which can be connected directly or indirectly, unless there is a clear statement to the contrary.

[0036] Conditional language used herein, such as "can," "might," "could," or "for example," unless otherwise specifically stated or understood otherwise in the context in which it is used, is generally intended to convey that certain embodiments include, while other embodiments do not include, certain features, elements, and / or states. Thus, such conditional language is generally not intended to imply that one or more embodiments require features, elements, and / or states in any way, or that one or more embodiments must include logic for determining, with or without author input or prompting, whether such features, elements, or states are included in any particular embodiment or will be performed in any particular embodiment. Furthermore, the use of the term "or" is inclusive (not exclusive), so that, for example, when used to connect a list of elements, the term "or" means one, some, or all of the elements in the list. Furthermore, the term "each," as used herein, in addition to having its ordinary meaning, may also refer to any subset of a set of elements to which the term "each" is applied.

[0037] The term "based on" should be understood as meaning "based, at least in part, on." The terms "one embodiment" and "an embodiment" should be interpreted as meaning "at least one embodiment." The term "another embodiment" should be interpreted as meaning "at least one other embodiment." Additional explicit and implicit definitions may be included below. Furthermore, unless specifically stated otherwise, phrases such as "at least one of X, Y, and Z" should be understood in context and are generally used to convey that an item, term, etc. can be X, Y, or Z, or a combination thereof.

[0038] Of course, without departing from the scope and essential features of the present disclosure, the present disclosure can be implemented in other specific ways other than those described herein. One or more specific processes in the specific processes discussed below can be performed in any communication transceiver including one or more appropriately configured processing circuits, which, in some embodiments, can be embodied in one or more application specific integrated circuits (ASICs). In some embodiments, these processing circuits may include one or more microprocessors, microcontrollers, and / or digital signal processors, which are programmed with appropriate software and / or firmware to perform one or more of the above-mentioned operations or their variants. In some embodiments, these processing circuits may include custom hardware to perform one or more of the above-mentioned functions. Therefore, the present embodiment is considered to be illustrative and non-restrictive in all aspects.

[0039] While several embodiments of the present disclosure will be shown in the drawings and described in the following detailed description, it will be understood that the disclosure is not limited to the described embodiments, but is capable of many arrangements, modifications, and substitutions without departing from the present disclosure and as will be set forth and defined in the claims.

[0040] Furthermore, it is noted that although the following description of some embodiments of the present disclosure is given in the context of RF communication circuits, the present disclosure is not limited thereto.

[0041] Figure 1 FIG. 1 is a block diagram illustrating an exemplary hot-swap enabling system 10 according to an embodiment of the present disclosure. Figure 1As shown, the system 10 can include a -48V (N48V) backplane and a rack of removable modules (or plug-in modules) 120. The -48V approach originates from traditional telecommunications switching system technology. Examples can be seen in Advanced Telecommunications Computing Architecture (ATCA) systems, optical networks, base stations, and blade servers. As the voltage typically obtained from a battery pack, 48V is chosen because power and signals can be transmitted over long distances without significant loss, and under normal conditions, this voltage level is not high enough to pose a serious risk of electric shock. Negative polarity is chosen because moisture is inevitably present when exposed to the elements, and the migration of metal ions from the anode to the cathode is much less corrosive when the positive electrode is grounded. However, the present disclosure is not limited thereto. In some other embodiments, another voltage level can be used, such as +12V or any other appropriate voltage level.

[0042] refer to Figure 1 , each module 120 can be capable of being withdrawn and / or replaced without affecting the normal operation of any adjacent modules 120 in the rack. In the absence of hot-swappable modules, each of the modules 120 can provide a considerable amount of load capacitance to the power line, typically on the order of milliamps. When a module 120 is first inserted, its uncharged capacitors require as much current as is available to charge the load (e.g., load 123). If this inrush current is not limited, it can lower the terminal voltage, resulting in a significant voltage deficit on the main backplane 110, resetting many of the adjacent modules 120 on the system 10, and damaging the module's connector due to the high initial current.

[0043] This can be solved by the hot-swap module 121, which carefully controls the inrush current to ensure a safe power-up interval. As will be described in detail later, the hot-swap module 121 can also continuously monitor the power supply current after power-up to prevent short circuits and overcurrent conditions during normal operation.

[0044] As described above, the inrush current of a switch-mode hot-swap module can be controlled by a current hysteresis circuit. In order to overcome or at least partially alleviate some of the defects of existing current hot-swap modules (such as those mentioned in the background technology section), a switch-mode hot-swap solution is proposed. This switch-mode hot-swap solution can have more than one current hysteresis that works under different conditions. Specifically, during the power-on phase, the hot-swap module can use a low current hysteresis to charge the output bulk capacitor to constrain the inrush current, thereby solving the high inrush current problem. After the charging process is completed, the current hysteresis will automatically switch from low to high, and the high current hysteresis can ensure that the hot-swap module will not be triggered under full load and PLD (power line disturbance) conditions. In this way, the hot-swap solution according to some embodiments of the present disclosure can solve the high inrush current problem while having no impact under normal operating conditions.

[0045] Next, we will refer to Figures 2 to 6 A hot-swap solution according to some embodiments of the present disclosure is described in detail.

[0046] Figure 2 is a block diagram illustrating an exemplary current limiter 200 according to an embodiment of the present disclosure. In some embodiments, the current limiter 200 may be Figure 1 The hot-swap module 121 is shown as a part thereof and can be used as a sub-circuit of the hot-swap module 121 to provide hot-plug functionality.

[0047] like Figure 2 As shown, the current limiter 200 may include a current limiting module 210 having an input terminal, an output terminal, and a control terminal. The current limiting module 210 may be configured to limit a current inputted via its input terminal to within a current limiting range.

[0048] For example, in some embodiments, the current limiting module 210 can be a buck converter, and its switch can be controlled by a control terminal. With this configuration, the current output via the output terminal can be controlled to increase when the switch is closed (on state) and decrease when the switch is open (off state), and thus the output current can be controlled to be within a current limit range. In addition, by adjusting the time points when the switch is turned on and off, different current limit ranges can be achieved.

[0049] refer to Figure 2The current limiter 200 may further include a range control module 220, which may have a control terminal and a sense terminal. In some embodiments, the control terminal may be coupled to a control terminal of the current limit module 210, and the sense terminal may be coupled to an output terminal of the current limit module 210. The range control module 220 may be configured to generate a control signal based at least on a current output via the output terminal of the current limit module 210 and sensed at a sense terminal of the range control module 210. Furthermore, the range control module 220 may be further configured to output a control signal via its control terminal such that the current limit range can be dynamically adjusted based on the control signal.

[0050] There are many methods for sensing the current output by the current limiting module 210, for example, methods based on Ohm's law, Faraday's law of induction, magnetic field sensors, Faraday effect, etc. For example, a shunt resistor can be connected in series with the output terminal of the current limiting module 210, and the voltage drop across the shunt resistor can be sensed. In this way, the current flowing through the shunt resistor can be calculated based on the resistance and voltage drop of the shunt resistor according to Ohm's law. For another example, since the wires or traces on the PCB board may have resistance, and therefore it can be used as a shunt resistor. The current can be sensed according to Ohm's law. For another example, a current transformer or a Rogowski coil can be used to sense the current output by the current limiting module 210 based on Faraday's law of induction. However, the present disclosure is not limited to the above-mentioned methods for sensing current.

[0051] Once the current is sensed, a control signal can be generated based on the sensed current. For example, when the sensed current has a level greater than or equal to the upper limit of the current limit range, a control signal having a level that can turn off the switch of the current limiting module 210 can be generated, thereby reducing the current output by the current limiting module 210. On the other hand, when the sensed current has a level less than or equal to the lower limit of the current limit range, a control signal having a level that can turn on the switch of the current limiting module 210 can be generated, thereby increasing the current output by the current limiting module 110. Through the collaboration of the current limiting module 210 and the range control module 220, the current output by the current limiter 200 can be controlled within the current limit range.

[0052] In addition, the range control module 220 can dynamically adjust the timing of its output control signal so that the current limit range can be dynamically adjusted as needed.

[0053] With this current limiter design, hot-swappable modules (e.g. Figure 1The module shown in the figure may have more than one current hysteresis. The hot-swap module can adjust the power-on inrush current in the early stage with low current hysteresis, while still operating normally in the later stage with high current hysteresis. In addition, such a design can minimize the possibility of triggering the on-site PSU overcurrent protection when powering up multiple plug-in modules at the same time, and minimize the risk of burning out the hot-swap switch MOSFET during power-up, making the final product more reliable and robust.

[0054] Next, we will refer to Figure 3 A more specific embodiment of the current limiter is described.

[0055] Figure 3 FIG. 3 is a block diagram illustrating another exemplary current limiter 300 according to an embodiment of the present disclosure. Figure 3 As shown, current limiter 300 may include a current limiting module 310 and a range control module 320. Except for the detailed structure of range control module 320, current limiting module 310 and range control module 320 may be similar to current limiting module 210 and range control module 220, respectively. In other words, range control module 320 is a possible implementation of range control module 220. Therefore, for the sake of simplicity, a detailed description of current limiting module 310 is omitted.

[0056] refer to Figure 3 The range control module 320 may include a charging completion indication module 321 , a range selection module 323 , a current sensing module 325 and a switch driving module 327 .

[0057] like Figure 3 As shown, the charging completion indication module 321 may have an input terminal and an output terminal, and is configured to output a charging completion indication signal via the output terminal after a first preset time period has passed since the first trigger signal was received via the input terminal. With this configuration, the charging completion indication signal can be used to distinguish different stages, and different current hysteresis can be used during different stages. For example, before outputting the charging completion indication signal, the range control module 320 may operate in a low current hysteresis mode, and after outputting the charging completion indication signal, the range control unit 320 may operate in a high current hysteresis mode. However, the present disclosure is not limited thereto. For example, in some other embodiments, the charging completion indication module 321 may output multiple signals indicating more than two stages.

[0058] In addition, if Figure 3As shown, the input terminal of the charge completion indication module 321 can be coupled to the third terminal of the switch driving module 327. In some embodiments, the first trigger signal can be the last on-signal input to the control terminal of the current limiting module 310, and no off-signal is input to the input terminal of the current limiting module 310 after the first trigger signal until the first preset time period expires. For example, the first trigger signal can be the last rising edge of the signal in row "P2", followed by a "10ms" interval, such as Figure 5 As shown. In some embodiments, the first preset time period may be 10 ms. However, please note that "10 ms" is merely an example of the first preset time period, and any other suitable time period during which the capacitor in the current limiter 300 can be fully charged may be used. In addition, please note that the first trigger signal is not limited to the signal output via the third terminal of the switch driver module 327. In some other embodiments, the first trigger signal may be any other suitable signal.

[0059] Return Reference Figure 3 The range selection module 323 may have an input terminal and an output terminal, the input terminal being coupled to the output terminal of the charge completion indication module 321, and the range selection module 323 being configured to initially output a first range selection signal via its output terminal, and to output a second range selection signal via its output terminal when the charge completion indication signal is received via its input terminal. In some embodiments, the second range selection signal may be associated with a current limit range that is different from the current limit range associated with the first range selection signal. Utilizing the range selection module 323, different current limit ranges (or different current hysteresis modes) may be selected, for example, based on the output of the charge completion indication module 321. However, the present disclosure is not limited thereto. In some other embodiments, the range selection module 323 may output different range selection signals based on other criteria.

[0060] In addition, the current sensing module 325 may have a first terminal and a second terminal, the first terminal being used as a sensing terminal of the range control module 320, and the current sensing module 325 being configured to sense the current at its first terminal and output a sensing signal indicating the sensed current via its second terminal. Figure 2 The output current from the current limit module 310 is sensed in a similar manner as shown.

[0061] Furthermore, the switch driver module 327 may have a first terminal coupled to the output terminal of the range selection module 323, a second terminal coupled to the second terminal of the current sensing module 325, and a third terminal serving as a control terminal of the range control module 320. The switch driver module 327 is configured to output a control signal based on the signals received at the first and second terminals. Using this switch driver module 327, the range control module 320 may generate different control signals based on the current limit range (or current hysteresis mode) selected by the range selection module 323 and the current sensed by the current sensing module 325. The control signals may be used to control the current limit module 310, thereby implementing a multi-current hysteresis solution.

[0062] In some embodiments, for example, some embodiments using an N-type MOSFET as a switch, the charge completion indication signal may be a high-level voltage signal, the first range selection signal may be a low-level voltage signal, and the second range selection signal may be a high-level voltage signal. In some embodiments, the sensing signal may be a voltage signal having a level indicating the current sensed at the first terminal of the current sensing module 325. However, the present disclosure is not limited thereto. For example, for a P-type transistor, an active low signal is required rather than an active high signal, and therefore, in this case, the charge completion indication signal may be a low-level voltage signal, the first range selection signal may be a high-level voltage signal, and the second range selection signal may be a low-level voltage signal. In addition, in some other embodiments using N-type MOSFETs and P-type MOSFETs in a mixed manner, some of the signals may be active high signals, while the rest may be active low signals, and therefore the present disclosure is not limited thereto.

[0063] Through the above configuration, the current limiter 300 can achieve the technical effect similar to that of the current limiter 200. Therefore, the hot-swap module (e.g., Figure 1 The module shown in the figure can have more than one current hysteresis. These current hysteresis can adjust the power-on inrush current in the early stage with low current hysteresis, while still enabling normal operation in the later stage with high current hysteresis. In addition, such a design can minimize the possibility of triggering the on-site PSU overcurrent protection when powering up multiple plug-in modules at the same time, and minimize the risk of burning out the hot-swap switch MOSFET during power-up, making the final product more reliable and robust.

[0064] Next, we will refer to Figure 4 A more specific embodiment of the current limiter is described.

[0065] Figure 4 FIG. 4 is a block diagram illustrating another exemplary current limiter 400 according to an embodiment of the present disclosure. Figure 4As shown, current limiter 400 may include a current limiting module 410 and a range control module. Except for the detailed structures of current limiting module 410 and range control module shown, current limiting module 410 and range control module may be similar to current limiting module 210 / 310 and range control module 220 / 320, respectively. In other words, current limiting module 410 is a possible implementation of current limiting module 210 and / or current limiting module 310, while range control module 420 is a possible implementation of range control module 220 and / or range control module 320.

[0066] like Figure 4 As shown, current limiting module 410 may include a switch (Q1) 411, an inductor (L1) 413, and a diode (D1) 415. In some embodiments, switch 411 may have a first terminal serving as an input terminal of current limiting module 410, a second terminal, and a control terminal serving as a control terminal of current limiting module 410. Current limiting module 410 is configured to be turned on or off in response to an on signal or an off signal (i.e., a control signal) input via the control terminal. Furthermore, inductor 413 may have a first terminal coupled to the second terminal of switch 411 and a second terminal serving as an output terminal of current limiting module 410. Furthermore, diode 415 may have a first terminal coupled to the second terminal of switch 411 and a second terminal connected to ground, wherein the forward direction of diode 415 may be from the first terminal to the second terminal. Furthermore, current limiting module 410 may optionally further include a capacitor 417, which may have a first terminal coupled to the second terminal of inductor 413 and a second terminal connected to ground. Furthermore, there may be more than one capacitor 417 in current limiting module 410.

[0067] With this configuration, the switch 411, the inductor 413, the diode 415 and the optional capacitor 417 can constitute a buck converter, which can be controlled by a control signal received via the control terminal of the switch 411. The current limiting module 410 can be respectively Figure 2 and Figure 3 The illustrated current limit module 210 and / or current limit module 310 operate in a similar manner.

[0068] Specifically, the current limiting module 410 can be best understood in terms of the relationship between the current and voltage across inductor 413. Starting when switch 411 is open (off state), the current in current limiting module 410 is zero. When switch 411 is first closed (on state), the current will begin to increase, and inductor 413 will develop an opposite voltage across its terminals in response to the changing current. This voltage drop cancels the voltage at the source (i.e., the voltage across the Vin terminal (e.g., -48V) and the GND terminal), thereby reducing the net voltage across the load (e.g., a load connected across the GND terminal and the Vout terminal). Over time, the rate of change of the current decreases, and the voltage across inductor 413 also decreases, thereby increasing the voltage at the load. During this period, the inductor stores energy in the form of a magnetic field. If switch 411 is opened while the current is still changing, there will always be a voltage drop across inductor 413, so the net voltage at the load (e.g., Vout) will always be less than the input voltage source (e.g., Vin). When switch 411 is opened again (off state), the voltage source is removed from the circuit and the current decreases. The reduced current creates a voltage drop across inductor 413 (the opposite of the voltage drop during the on state), and inductor 412 now becomes a current source. The energy stored in the magnetic field of inductor 413 supports the current flowing through the load. This current flows when the input voltage source is disconnected, and when combined with the current flowing during the on state, the total current is greater than the average input current (which is zero during the off state). This "increase" in average current compensates for the decrease in voltage and ideally maintains the power supplied to the load. During the off state, inductor 413 releases its stored energy to the rest of the circuit. If switch 411 is closed again before inductor 413 is fully discharged (on state), the voltage at the load will remain greater than zero. In other words, current limit module 410 can limit its output current to a specified current limit range based on the timing used to turn switch 411 on and off.

[0069] In some embodiments, switch 411 may be a metal oxide semiconductor field effect transistor (MOSFET), and the first terminal of MOSFET 411 may be one of its source and drain, the second terminal of MOSFET 411 may be the other of its source and drain, and the control terminal of MOSFET 411 may be its gate. In some embodiments, MOSFET 411 may be an N-type MOSFET 411, i.e., the turn-on signal is a high-level voltage signal, and the turn-off signal is a low-level voltage signal. However, the present disclosure is not limited thereto. For example, in some other embodiments, switch 411 may be a P-type MOSFET, and an active low-voltage signal may be used.

[0070] Similar to the charging completion indication module 321, the charging completion indication unit 420 may have an input terminal and an output terminal, and is configured to output a charging completion indication signal (at reference point P3) via the output terminal after a first preset time period has passed since the first trigger signal was received via the input terminal. With this configuration, the charging completion indication signal can be used to distinguish different stages, during which different current hysteresis can be used. For example, before outputting the charging completion indication signal, Figure 4 The range control module shown may operate in a low current hysteresis mode, and after outputting the charge completion indication signal, the range control module may operate in a high current hysteresis mode. However, the present disclosure is not limited thereto. For example, in some other embodiments, the charge completion indication module 420 may output multiple signals indicating two or more stages, respectively.

[0071] In addition, the input terminal of the charge completion indication module 421 can be coupled to the third terminal (or reference point P2) of the switch driving module 450. In some embodiments, the first trigger signal can be the last on-signal input to the control terminal of the current limiting module 410 or the control terminal of the switch 411, and no off-signal is input to the control terminal of the current limiting module 410 or the control terminal of the switch 412 after the first trigger signal until the first preset time period expires. For example, the first trigger signal can be the last rising edge of the signal in row "P2", followed by a "10ms" interval, such as Figure 5 As shown. In some embodiments, the first preset time period may be 10 ms. However, please note that "10 ms" is merely an example of the first preset time period, and any suitable time period during which the capacitor in the current limiter 400 can be fully charged may be used. Furthermore, please note that the first trigger signal is not limited to the signal at P2. In some other embodiments, the first trigger signal may be any other suitable signal.

[0072] like Figure 4As shown, the range selection module 430 may include an OR gate 431 and an auxiliary power supply 433. The OR gate 431 may have a first input terminal serving as an input terminal of the range selection module 430, a second input terminal, and a third output terminal serving as an output terminal of the range selection module 430. The range selection module 430 is configured to perform a logical OR operation on the inputs from the first input terminal and the second input terminal, and output a signal indicating the result of the logical OR operation via the third output terminal. The auxiliary power supply 433 may have a first terminal coupled to the third output terminal of the OR gate 431, a second terminal coupled to the output terminal of the current limit module 410, a third terminal coupled to ground, and a fourth terminal coupled to the second input terminal of the OR gate 431. The auxiliary power supply 433 is configured to output an auxiliary power ready signal (at reference point P5) via the fourth terminal after receiving the auxiliary power enable signal (at reference point P4) via the first terminal. In some embodiments, the auxiliary power ready signal and / or the auxiliary power enable signal may be a high-level voltage signal.

[0073] With this configuration, once the charge completion indication signal is received by the OR gate 431, the OR gate 431 can output an auxiliary power enable signal to the auxiliary power supply 433 to enable the auxiliary power supply 433, which in turn outputs an auxiliary power ready signal to the OR gate 431. In this manner, the range selection module 430 can become self-locking logic and thus will use high hysteresis until the entire module is powered off or restarted after the capacitor is fully charged (guaranteed by the first preset time period).

[0074] Additionally, in some embodiments, the auxiliary power supply 433 can generate several power rails to power other modules, such as MOSFET drivers, low dropout (LDO) regulators, and logic components.

[0075] like Figure 4 As shown, the current sensing module 440 can operate in a similar manner to the current sensing module 325. Specifically, the current sensing module 440 can have a first terminal and a second terminal, the first terminal being used as Figure 4 The current sensing module 440 is configured to sense the current at its first terminal and output a sense signal indicating the sensed current via its second terminal. Figure 2 and Figure 3 The output current from the current limiting module 410 is sensed in a similar manner as shown.

[0076] Reference again Figure 4 , the switch driving module 450 may include a range signal processing module and a comparator 458. Figure 4As shown, the range signal processing module can be composed of multiple components, such as transistors and resistors. The range signal processing module can have an input terminal and an output terminal, the input terminal being coupled to the output terminal of the range selection module 430, and the range signal processing module being configured to output a reference signal via the output terminal, the reference signal being dynamically determined based on a signal received via the input terminal of the range signal processing module. The comparator 458 can have a first input terminal coupled to the output terminal of the range signal processing module, a second input terminal coupled to the second terminal of the current sensing module 440, and an output terminal serving as a third terminal of the switch driving module 450, and the comparator 458 is configured to output a control signal via the output terminal based on a comparison of the reference signal and the sense signal received via the first input terminal and the second input terminal, respectively.

[0077] With this configuration, the switch driving module 450 can generate different control signals based on the current limit range (or current hysteresis mode) selected by the range selection module 430 and the current sensed by the current sensing module 440, and the control signals can be used to control the current limit module 410, thereby realizing a multi-current hysteresis solution.

[0078] like Figure 4 As shown, the range signal processing module may include two transistors T1 and T2 and five resistors R1-R5. The first transistor T1, 451, may have a first terminal, a second terminal coupled to ground, and a control terminal serving as an input terminal of the range signal processing module. The second transistor T2, 452 may have a first terminal, a second terminal coupled to ground, and a control terminal coupled to the first terminal of T1, 451. The first resistor R1, 453 may have a first terminal coupled to a direct current (DC) power supply and a second terminal coupled to the first terminal of T1, 451. The second resistor R2, 454 may have a first terminal coupled to the first input terminal of a comparator 458 and a second terminal coupled to the first terminal of T2, 452. The third resistor R3, 455 may have a first terminal coupled to the first input terminal of the comparator 458 and a second terminal coupled to ground. The fourth resistor R4, 456 may have a first terminal coupled to the DC power supply and a second terminal coupled to the first input terminal of the comparator 458. The fifth resistor R5 , 457 may have a first terminal coupled to the output terminal of the comparator 458 and a second terminal coupled to the first input terminal of the comparator 454 .

[0079] With this configuration, the comparator 458 can compare the sense signal provided from the current sense module 440 with a dynamically changing reference voltage and, in turn, output a control signal that can be associated with different current limit ranges.

[0080] For example, when the range selection module 430 outputs a low-level voltage signal indicating low hysteresis, T1 451 may be turned off, and thus T2 452 may be turned on due to the high voltage applied from the DC power supply. In this case, R2 454 and R3 455 are connected in parallel, resulting in a lower equivalent resistance, and the voltage at the first input terminal of the comparator 458 may be lower due to the lower equivalent resistance of R2 454 and R3 455, given R4 456. On the other hand, when the range selection module 430 outputs a high-level voltage signal indicating high hysteresis, T1 451 may be turned on, and thus the control terminal of T2 452 may be grounded, and T2 452 may be turned off. In this case, R2 454 is no longer connected in parallel with R3 455, and since the equivalent resistance of R2 454 and R3 455 is higher than in the low hysteresis mode, the voltage at the first input terminal of the comparator 458 may be higher.

[0081] In other words, a dynamically adjustable current limit range can be achieved by comparing the sensed signal indicative of the current sensed at the output terminal of the current limit module 410 with a reference signal that can be dynamically changed by the range selection module 430. Figure 4 In the embodiment of the present invention, low hysteresis can be used until the charge completion indication module 420 issues a charge completion indication signal, after which high hysteresis can be used. In this way, the current limiter 400 can achieve a similar technical effect as the current limiter 200 and / or the current limiter 300. Therefore, the hot swap module (e.g., Figure 1 The module shown in the figure can have more than one current hysteresis, which can adjust the power-on inrush current in the early stage with low current hysteresis, while still maintaining normal operation in the later stage with high current hysteresis. In addition, such a design can minimize the possibility of triggering the on-site PSU overcurrent protection when powering up multiple plug-in modules at the same time, and minimize the risk of burning out the hot-swap switch MOSFET during power-up, making the final product more reliable and robust.

[0082] In addition, in some embodiments, the current limiter 400 may optionally further include a voltage protection module 460. The voltage protection module 460 may have a first terminal coupled to the input terminal of the current limit module 410, a second terminal coupled to ground, and a third terminal coupled to the enable terminal of the range control module, and may be configured to output an enable signal via the third terminal when the voltage detected across the first terminal and the second terminal is within a safe range. In some embodiments, the enable signal may be a high-level voltage signal.

[0083] Therefore, the switch driver module 450 may further include an optional switch driver 459. The switch driver 459 may have a first terminal coupled to the output terminal of the comparator 458, a second terminal serving as a third terminal of the switch driver module 450 (instead of the comparator 458 output terminal), and a third terminal serving as an enable terminal of the range control module, and the switch driver 459 is configured to output the control signal only when an enable signal is received at its third terminal.

[0084] In addition, the charge completion indication module 420 may further include a disable terminal coupled to the enable terminal of the switch driver 459 and further configured to output a disable signal via the disable terminal after a second preset time period has elapsed since the second trigger signal was received via the input terminal. In some embodiments, the disable signal may be a low-level voltage signal that is capable of disabling the enable signal output from the voltage protection module 460. In some embodiments, the input terminal of the charge completion indication module 420 may be coupled to a third terminal of the switch driver module 450, and the second trigger signal may be a first on-state signal input to the control terminal of the current limiting module 410 after the enable signal changes from a low-level voltage signal to a high-level voltage signal, and the second preset time period may be 250 ms. Note that 250 ms is merely an example of the second preset time period and the present disclosure is not limited thereto.

[0085] With this configuration, the current limiter 400 can further provide an overvoltage / undervoltage protection function. For example, when an undervoltage or overvoltage condition is detected across the Vin terminal and the GND terminal, the enable signal is not output, and thus the switch driver 459 can output a control signal that turns off the switch 411 to protect the current limiter 400 from any damage caused by the undervoltage / overvoltage condition. In addition, when the charge completion indication module 420 detects an overcharge event, for example, by detecting a high-level signal at P2 for a second preset time period (e.g., Figure 5 As shown), a disable signal may be provided to switch driver 459 to turn off switch 411 so that further charging is not allowed and the circuit is protected.

[0086] Next, we will refer to Figure 5 The timing diagram of FIG. 1 describes in detail how the current limiter 400 operates.

[0087] Figure 5 This is to show how to operate according to the embodiment of the present disclosure Figure 4 The timing diagram of the current limiter 400 is shown in FIG. Figure 5 , signals such as Vin, P1, P2, P3, P4, P5, and Vout at different points of the current limiter 400 are shown. In addition, reference symbols OV and UV indicate overvoltage and undervoltage levels of the Vin signal, respectively.

[0088] like Figure 5 As shown, the current limiter 400 is powered on and Vin gradually increases. Before Vin becomes higher than or equal to the undervoltage level, the voltage protection module 460 will output a low level signal as shown in row "P1", and thus the switch driver 459 will control the switch 411 to be in the off state, and thus no current flows in the current limiter module 410.

[0089] Thereafter, in the first phase T1, the voltage protection module 460 will output an enable signal because the input voltage is between undervoltage and overvoltage, and the switch driver 459 can operate based on the comparison between the sensed current and the adjustable reference voltage. Since the charge completion indication module 420 has not yet issued a charge completion indication signal (as shown in row "P3"), it is currently in the low hysteresis mode. Therefore, in the first phase T1, the first signal can be input to the current limiter 400 so that the first signal has a current level limited to the first current limit range (e.g., the range corresponding to the low hysteresis mode).

[0090] When a trigger signal is output from the switch driver 459 to the charge completion indication module 420 (e.g., the last rising edge of the signal of row “P2” immediately following the “10ms” interval), the charge completion indication module 420 may set a time interval having a first preset time period (e.g., Figure 5 When the timer expires, which means that the capacitor is fully charged and the high hysteresis mode should be started, the charge completion indication module 420 outputs a charge completion indication signal to the range selection module 430, changes the reference voltage at the first input terminal of the comparator 458, and finally changes the hysteresis mode from low to high, as shown in the "P3" and "P4" rows.

[0091] Therefore, in a second phase after a first preset period of time has passed since the first signal was received via the input terminal of the current limiter 400, a second signal is input to the current limiter 300 such that the second signal has a current level limited to a second current limit range that is different from the first current limit range. For example, the second current limit range may be associated with a high hysteresis mode, while the first current limit range may be associated with a low hysteresis mode. In some embodiments, the second current limit range may have upper and lower limits that are higher than those of the first current limit range. After the hysteresis mode changes from low to high, a higher voltage signal may be observed in the "Vout" line.

[0092] In addition, if Figure 5As shown, when the Vin signal exceeds the overvoltage level, the voltage protection module 460 can output a low-level voltage signal, as shown in row "P1", which causes the switch driver 459 to turn off the switch 411, and the output voltage decreases as shown in row "Vout". In other words, the voltage protection module 460 can output a disable signal via its third terminal in response to an overvoltage event or undervoltage event detected across its first and second terminals, causing the switch 411 to be turned off.

[0093] Subsequently, when the input voltage "Vin" returns to the normal range between the UV and OV levels, the voltage protection module 460 can again output an enable signal via its third terminal in response to detecting the disappearance of the overvoltage event or undervoltage event, so that the switch 411 is controlled only by the range control module. In other words, the switch 411 can be turned on or off based on the comparison between the sensed signal from the current sensing module 440 and the reference voltage in the current hysteresis mode.

[0094] In addition, if Figure 5 As shown, when a short circuit condition is detected on the load side, for example, between the terminals "GND" and "Vout", as shown in the "Output Short Circuit" in the figure, the output voltage Vout will drop to zero, and the capacitor 417 will never be fully charged, and the charge completion indication module 420 will never receive its trigger signal, and therefore the switch driver 459 will never be disabled and will remain operational for an indefinite time, as shown in row "P2". In this case, the charge completion indication module 420 can output a disable signal via its disable terminal after a second preset time period has passed since the second trigger signal was received via its input terminal, so that the switch 411 can be turned off and the current limiter 400 can be placed in a latching mode or a hiccup mode. In some embodiments, the second trigger signal can be a first on-signal input to the control terminal of the current limiting module after the enable signal changes from a low-level voltage signal to a high-level voltage signal. In some embodiments, the second preset time period can be 250ms, for example, as shown in row "P2". Figure 5 However, the present disclosure is not limited thereto, and the second preset time period may be a time period of appropriate length.

[0095] Figure 6 is a flow chart illustrating an exemplary method 600 for operating a current limiter according to an embodiment of the disclosure.

[0096] Figure 6is a flow chart of an exemplary method 600 at a current limiter (e.g., current limiter 200, 300, or 400) according to an embodiment of the present disclosure. Method 600 may include step S610 and step S620. However, the present disclosure is not limited thereto. In some other embodiments, method 600 may include more steps, fewer steps, different steps, or any combination thereof. In addition, the steps of method 600 may be performed in an order different from the order described herein. In addition, in some embodiments, the steps in method 600 may be divided into multiple sub-steps and performed by different entities, and / or multiple steps in method 600 may be combined into a single step. In some embodiments, method 600 may be performed by the current limiter itself, a hot-swappable module including the current limiter, a plug-in module including the hot-swappable module, a backplane into which the plug-in module is inserted, or any other device electrically coupled to the current limiter. For example, when a plug-in module including a current limiter is tested before delivery to its customer, method 600 may be performed by a tester device indirectly coupled to the plug-in module, which provides appropriate input signals to the plug-in module and thus to the current limiter via a control backplane.

[0097] The method 600 may begin at step S610 , where in a first stage, a first signal may be input into a current limiter such that the first signal has a current level limited within a first current limit range.

[0098] In step S620, in the second stage, after a first preset time period has passed since the first signal was received via the input terminal of the current limiter, a second signal may be input into the current limiter so that the current level of the second signal is limited to a second current limiting range, wherein the second current limiting range may be different from the first current limiting range.

[0099] In some embodiments, the second current limit range may have an upper limit and a lower limit that are higher than the upper limit and the lower limit of the first current limit range. In some embodiments, the method may further include: the voltage protection module outputting a disable signal via its third terminal in response to detecting an overvoltage event or an undervoltage event across its first and second terminals, so that the switch is turned off. In some embodiments, the method may also include: the charge completion indication module outputting an enable signal via its third terminal in response to detecting the disappearance of the overvoltage event or the undervoltage event, so that the switch is controlled only by the range control module. In some embodiments, the method may also include: the charge completion indication module outputting a disable signal via its disable terminal after a second preset time period has passed since the second trigger signal was received via its input terminal, so that the switch is turned off.

[0100] Using this method of operating the current limiter, hot-swappable modules (e.g. Figure 1 The module shown in the figure can operate in more than one current hysteresis mode. These current hysteresis modes can adjust the power-on inrush current in the early stage with low current hysteresis, while still enabling normal operation in the later stage with high current hysteresis. In addition, such a design can minimize the possibility of triggering the on-site PSU overcurrent protection when powering up multiple plug-in modules at the same time, and minimize the risk of hot-swap switch MOSFET burning out during power-up, making the final product more reliable and robust.

[0101] The present disclosure has been described with reference to the embodiments and accompanying drawings. It should be understood that various modifications, substitutions, and additions may be made by those skilled in the art without departing from the spirit and scope of the present disclosure. Therefore, the scope of the present disclosure is not limited to the specific embodiments described above, but is limited only by the appended claims and their equivalents.

Claims

1. A current limiter (200, 300, 400), comprising: A current limiting module (210, 310, 410) having an input terminal, an output terminal, and a control terminal, and configured to limit a current input via its input terminal to within a current limiting range; as well as a range control module (220, 320) having a control terminal coupled to the control terminal of the current limiting module (210, 310, 410) and a sense terminal coupled to the output terminal of the current limiting module (210, 310, 410), wherein the range control module (220, 320) is configured to generate a control signal based on at least the current output via the output terminal of the current limiting module (210, 310, 410) and sensed at the sense terminal, and output the control signal via its control terminal, such that the current limit range is dynamically adjustable based on the control signal; The range control module (220, 320) includes: a charging completion indication module (321, 420) having an input terminal and an output terminal, and configured to output a charging completion indication signal via the output terminal after a first preset time period has passed since a first trigger signal was received via the input terminal; A range selection module (323, 430) has an input terminal and an output terminal, the input terminal being coupled to the output terminal of the charge completion indication module (321, 420), and the range selection module (323, 430) being configured to initially output a first range selection signal via its output terminal, and when the charge completion indication signal is received via its input terminal, output a second range selection signal via its output terminal, the second range selection signal being associated with a current limit range different from the current limit range associated with the first range selection signal.

2. The current limiter (200, 300, 400) according to claim 1, wherein the current limiting module (210, 310, 410) comprises: a switch (411) having a first terminal and a second terminal serving as the input terminal of the current limiting module (210, 310, 410) and a control terminal serving as the control terminal of the current limiting module (210, 310, 410), and configured to be turned on or off in response to an on signal or an off signal input via the control terminal; an inductor (413) having a first terminal coupled to the second terminal of the switch (411) and a second terminal serving as the output terminal of the current limiting module (210, 310, 410); as well as A diode (415) has a first terminal coupled to the second terminal of the switch (411) and a second terminal connected to ground, wherein a forward direction of the diode (415) is from the first terminal to the second terminal.

3. The current limiter (200, 300, 400) according to claim 2, wherein the switch (411) is a metal oxide semiconductor field effect transistor (MOSFET) (411), The first terminal of the MOSFET (411) is one of its source and drain, the second terminal of the MOSFET (411) is the other of its source and drain, and the control terminal of the MOSFET (411) is its gate.

4. The current limiter (200, 300, 400) according to claim 3, wherein the MOSFET (411) is an N-type MOSFET (411), The on signal is a high-level voltage signal, and the off signal is a low-level voltage signal.

5. The current limiter (200, 300, 400) according to claim 2, wherein the current limiting module (210, 310, 410) further comprises: A capacitor (417) has a first terminal coupled to the second terminal of the inductor (413) and a second terminal connected to ground.

6. The current limiter (200, 300, 400) of claim 2, wherein the range control module (220, 320) further comprises: a current sensing module (325, 440) having a first terminal and a second terminal, the first terminal serving as the sensing terminal of the range control module (220, 320), and the current sensing module (325, 440) being configured to sense the current at its first terminal and output a sensing signal indicative of the sensed current via its second terminal; as well as A switch driving module (327, 450) has a first terminal coupled to the output terminal of the range selection module (323, 430), a second terminal coupled to the second terminal of the current sensing module (325, 440), and a third terminal serving as the control terminal of the range control module (220, 320), and the switch driving module (327, 450) is configured to output the control signal based on the signals received at the first terminal and the second terminal.

7. The current limiter (200, 300, 400) according to claim 6, wherein the input terminal of the charging completion indication module (321, 420) is coupled to the third terminal of the switch driving module (327, 450), wherein the first trigger signal is the last on signal input into the control terminal of the current limiting module (210, 310, 410), and no off signal is input into the control terminal of the current limiting module (210, 310, 410) after the first trigger signal until the first preset time period expires, and The first preset time period is 10ms.

8. The current limiter (200, 300, 400) according to claim 6, wherein the charge completion indication signal is a high level voltage signal, the first range selection signal is a low level voltage signal, and the second range selection signal is a high level voltage signal.

9. The current limiter (200, 300, 400) of claim 6, wherein the sense signal is a voltage signal having a level indicative of the current sensed at the first terminal of the current sensing module (325, 440).

10. The current limiter (200, 300, 400) of claim 6, wherein the range selection module (323, 430) comprises: an OR gate (431) having a first input terminal and a second input terminal serving as the input terminals of the range selection module (323, 430), and a third output terminal serving as the output terminal of the range selection module (323, 430), wherein the OR gate (431) is configured to perform a logical OR operation on the inputs from the first input terminal and the second input terminal, and output a signal indicating a result of the logical OR operation via the third output terminal; as well as An auxiliary power supply (433) has a first terminal coupled to the third output terminal of the OR gate (431), a second terminal coupled to the output terminal of the current limiting module (210, 310, 410), a third terminal coupled to the ground, and a fourth terminal coupled to the second input terminal of the OR gate (431), and the auxiliary power supply (433) is configured to output an auxiliary power ready signal via the fourth terminal after an auxiliary power enable signal is received via the first terminal.

11. The current limiter (200, 300, 400) of claim 10, wherein each of the auxiliary power ready signal and the auxiliary power enable signal is a high level voltage signal.

12. The current limiter (200, 300, 400) according to claim 6, wherein the switch driving module (327, 450) comprises: a range signal processing module (451-457) having an input terminal and an output terminal, the input terminal being coupled to the output terminal of the range selection module (323, 430), and the range signal processing module (451-457) being configured to output a reference signal via the output terminal, the reference signal being dynamically determined based on the signal received via the input terminal; as well as A comparator (458) having a first input terminal coupled to the output terminal of the range signal processing module (451-457), a second input terminal coupled to the second terminal of the current sensing module (325, 440), and an output terminal serving as the third terminal of the switch driving module (327, 450), and the comparator (458) is configured to output the control signal via the output terminal based on the comparison of the reference signal and the sensing signal received via the first input terminal and the second input terminal, respectively.

13. The current limiter (200, 300, 400) of claim 6, wherein the range control module (220, 320) further comprises an enable terminal, The current limiter (200, 300, 400) further includes a voltage protection module (460), the voltage protection module (460) having a first terminal coupled to the input terminal of the current limit module (210, 310, 410), a second terminal coupled to the ground, and a third terminal coupled to the enable terminal of the range control module (220, 320), and the voltage protection module (460) is configured to output an enable signal via the third terminal when a voltage detected across the first terminal and the second terminal thereof is within a safe range.

14. The current limiter (200, 300, 400) according to claim 13, wherein the enable signal is a high-level voltage signal.

15. The current limiter (200, 300, 400) according to claim 14, wherein the switch driving module (327, 450) comprises: a range signal processing module (451-457) having an input terminal and an output terminal, the input terminal being coupled to the output terminal of the range selection module (323, 430), and the range signal processing module (451-457) being configured to output a reference signal via the output terminal, the reference signal being dynamically determined based on the signal received via the input terminal; a comparator (458) having a first input terminal coupled to the output terminal of the range signal processing module (451-457), a second input terminal coupled to the second terminal of the current sensing module (325, 440), and an output terminal, wherein the comparator (458) is configured to output the control signal via the output terminal based on the comparison of the reference signal and the sense signal received via the first input terminal and the second input terminal, respectively; as well as A switch driver (459) having a first terminal coupled to the output terminal of the comparator (458), a second terminal serving as the third terminal of the switch drive module (327, 450), and a third terminal serving as the enable terminal of the range control module (220, 320), and the switch driver (459) being configured to output the control signal only when the enable signal is received at its third terminal.

16. The current limiter (200, 300, 400) according to claim 15, wherein the charge completion indication module (321, 420) further includes a disable terminal, the disable terminal being coupled to the enable terminal of the switch driver (459), and the charge completion indication module (321, 420) is further configured to output a disable signal via the disable terminal after a second preset time period has passed since a second trigger signal was received via the input terminal.

17. The current limiter (200, 300, 400) according to claim 16, wherein the disable signal is a low-level voltage signal, and the disable signal is capable of invalidating the enable signal output from the voltage protection module (460).

18. The current limiter (200, 300, 400) according to claim 17, wherein the input terminal of the charging completion indication module (321, 420) is coupled to the third terminal of the switch driving module (327, 450), wherein the second trigger signal is a first conduction signal input to the control terminal of the current limiting module (210, 310, 410) after the enable signal changes from a low-level voltage signal to a high-level voltage signal, and The second preset time period is 250ms.

19. The current limiter (200, 300, 400) according to claim 12 or 15, wherein the range signal processing module (451-457) comprises: a first transistor (451) having a first terminal, a second terminal coupled to the ground, and a control terminal serving as the input terminal of the range signal processing module; a second transistor (452) having a first terminal, a second terminal coupled to the ground, and a control terminal coupled to the first terminal of the first transistor (451); a first resistor (453) having a first terminal coupled to a direct current (DC) power source and a second terminal coupled to the first terminal of the first transistor (451); a second resistor (454) having a first terminal coupled to the first input terminal of the comparator (458) and a second terminal coupled to the first terminal of the second transistor (452); a third resistor (455) having a first terminal coupled to the first input terminal of the comparator (458) and a second terminal coupled to the ground; a fourth resistor (456) having a first terminal coupled to the DC power supply and a second terminal coupled to the first input terminal of the comparator (458); as well as A fifth resistor (457) has a first terminal coupled to the output terminal of the comparator (458) and a second terminal coupled to the first input terminal of the comparator (458).

20. A hot-swap module for an electronic device, comprising the current limiter (200, 300, 400) according to any one of claims 1-19.

21. A method of operating a current limiter (200, 300, 400) according to any one of claims 1 to 19, the method comprising: In a first stage, a first signal is input into the current limiter (200, 300, 400) so that the first signal has a current level limited within a first current limiting range; as well as In a second phase, after a first preset time period has elapsed since the first signal was received via the input terminal of the current limiter (200, 300, 400), a second signal is input into the current limiter (200, 300, 400) so that the second signal has a current level limited within a second current limiting range, The second current limiting range is different from the first current limiting range. 22 . The method of claim 21 , wherein the second current limit range has upper and lower limits that are higher than upper and lower limits of the first current limit range.

23. The method of claim 21, further comprising: In response to detecting an overvoltage event or an undervoltage event across the first and second terminals, the voltage protection module (460) outputs a disable signal via the third terminal thereof, so that the switch (411) is turned off.

24. The method according to claim 23, further comprising: In response to detecting the disappearance of the overvoltage event or the undervoltage event, the voltage protection module (460) outputs an enable signal via its third terminal, so that the switch (411) is controlled only by the range control module (220, 320).

25. The method of claim 21 , further comprising: The charging completion indication module (420) outputs a disable signal via its disable terminal after a second preset time period has passed since a second trigger signal was received via its input terminal, so that the switch (411) is turned off.

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