Forced current-sharing circuit, chip, motherboard, and electronic device

Abstract

The present application relates to the technical field of power supplies, and provides a forced current-sharing circuit, a chip, a motherboard, and an electronic device. A first end of each phase in a multi-phase coupling device is connected to an output end of a current channel, and a second end of each phase in the multi-phase coupling device is connected to the second ends of the other phases in parallel and then connected to a load. The coupling coefficient and mutual inductance between every two phases in the multi-phase coupling device are both 1, so that currents at the first and second ends of each phase in the multi-phase coupling device are equal to currents at the first and second ends of the other phases. The present application achieves active current sharing, avoids the problem of exceeding operational limits and resulting in shutdown due to overcurrent and overheating caused by different current flow rates, and eliminates the issue of causing simultaneous failure of surrounding devices, thus avoiding accidents such as thermal damage and improving the operational stability of the circuit board. The circuit structure is simple, and only the characteristics of passive components are utilized so that errors are not prone to occur, improving the reliability of the forced current-sharing circuit while increasing the power cycling and efficiency thereof.

Description

Forced current sharing circuit, chip, mainboard and electronic equipment

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to the Chinese patent application filed with the China Patent Office on September 25, 2023, with application number 202311237728.1, and application name "A forced current equalization circuit, chip, motherboard and electronic device", all contents of which are incorporated by reference into this application. Technical Field

[0003] The present application relates to the field of power supply technology, and in particular to a forced current sharing circuit, chip, motherboard and electronic equipment. Background Art

[0004] With the rapid development of cloud computing, artificial intelligence, and more recently, large AI models (such as the Chat Generative Pre-trained Transformer (ChatGPT), the power consumption of major chips such as CPUs (Central Processing Units) and GPUs (Graphics Processing Units) has continued to increase. This has led to a gradual increase in power supply current, which has also brought certain difficulties to the heat dissipation and layout of the board. When high current flows through the PCB (Printed Circuit Board) with slightly higher impedance, it will generate significant heat loss.

[0005] Current PCB boards are designed with EFuses (electronic fuses) of varying voltage levels to ensure a stable power supply. Due to the increased current, multiple EFuses are often connected in parallel to ensure current flow. However, current designs rely solely on wiring layout to achieve passive current sharing among multiple EFuses, not active forced current sharing.

[0006] However, passive current sharing may cause different currents due to the Efuse manufacturing process or product batches. Some Efuses may exceed their operating limits, overcurrent, overheat, and stop working. Other parallel Efuses need to bear their load current, causing the working condition to further deteriorate and even cause surrounding components to fail. For example, capacitor failure and fire will eventually bring the risk of burning the board.

[0007] Summary of the Invention

[0008] In view of the above problems, the present application is proposed to provide a forced current sharing circuit, chip, mainboard and electronic device that solve the above problems or partially solve the above problems.

[0009] An embodiment of the present application provides a forced current sharing circuit, the forced current sharing circuit comprising: a multi-phase coupling device and a plurality of current channels connected in parallel;

[0010] The first end of each phase in the multiphase coupling device is connected to the output end of a current channel;

[0011] The second end of each phase in the multiphase coupling device is connected in parallel with the second ends of other phases and then connected to the load;

[0012] The coupling coefficient and mutual inductance between each two phases in the multiphase coupling device are both 1, so that the current at the first end and the second end of each phase in the multiphase coupling device are equal to the current at the first end and the second end of other phases.

[0013] In some embodiments of the present application, the multiphase coupling device includes: a multiphase coupling transformer or a multiphase coupling inductor;

[0014] All phase winding coils in a multi-phase coupled transformer share a common magnetic core;

[0015] In the multi-phase coupled transformer, each two-phase winding coil is opposite-terminal coupled, and the coupling coefficient and mutual inductance between each two-phase winding coil are both 1; or,

[0016] All phase inductor coils in a multi-phase coupled inductor share a common magnetic core;

[0017] In the multi-phase coupled inductor, the inductor coils of each two phases are coupled with opposite-terminal terminals, and the coupling coefficient and mutual inductance between the inductor coils of each two phases are both 1.

[0018] In some embodiments of the present application, a first end of each phase winding coil in a multi-phase coupled transformer is connected to an output end of a current channel;

[0019] The second end of each phase winding coil in the multi-phase coupling transformer is connected in parallel with the second ends of the other phase winding coils and then connected to the load, and the first end of the n-1th phase winding coil and the second end of the nth phase winding coil are the same-named ends, where n ≥ 2; or

[0020] The first end of the inductor coil of each phase in the multi-phase coupled inductor is connected to the output end of a current channel;

[0021] The second end of each phase inductor in the multi-phase coupled inductor is connected in parallel with the second ends of the other phase inductors and then connected to the load, and the first end of the n-1th phase inductor and the second end of the nth phase inductor are the same end, where n≥2.

[0022] In some embodiments of the present application, the coupling coefficient and mutual inductance between each two-phase winding coils in the multi-phase coupled transformer are both 1, and the self-inductance of each phase winding coil is the same; or,

[0023] In a multi-phase coupled inductor, the coupling coefficient and mutual inductance between each two phase inductor coils are both 1, and the self-inductance of each phase inductor coil is the same.

[0024] In some embodiments of the present application, when the forced current sharing circuit is in a dynamic working state, when the current in the current channel connected to any phase changes, the remaining phases all induce electromotive force, so that the current output to the load changes at the same time, thereby making the output current at the second end of each phase equal.

[0025] In some embodiments of the present application, when the forced current sharing circuit is in a static working state, each phase in the multi-phase coupling device increases the loop impedance of the current channel connected to it, passively adjusting and reducing the uneven current ratio of multiple current channels.

[0026] In some embodiments of the present application, when the current sharing circuit is forced to be in a static working state, each phase in the multi-phase coupling device increases the loop impedance of the current channel connected thereto to prevent reaching the power limit.

[0027] In some embodiments of the present application, the forced current sharing circuit further includes: a plurality of electronic fuses, one electronic fuse being arranged in one current channel;

[0028] The first end of each phase in the multi-phase coupling device is connected to the output end of an electronic fuse, and the input end of each electronic fuse receives the current output by the previous stage circuit;

[0029] The second end of each phase in the multi-phase coupling device is connected in parallel with the second ends of other phases and then connected to the load.

[0030] In some embodiments of the present application, the forced current sharing circuit further includes: a current detection unit, a current source, a release resistor, and a plurality of release units;

[0031] The current detection unit is connected to the current source, and is used to detect the current output to the load, and send a control signal to the current source according to the detected current output to the load;

[0032] The current source is connected to the plurality of release units and the release resistors respectively, and is used to inject currents of different magnitudes into the release resistors according to the control signal;

[0033] A release unit is connected in parallel with one phase of the multi-phase coupling device and is used to release or maintain the energy stored in the parallel phase according to the magnitude of the current injected into the release resistor.

[0034] In some embodiments of the present application, the negative terminal of the current source is grounded, and the positive terminal is connected to the second terminals of the plurality of release units and the first terminal of the release resistor respectively;

[0035] The first ends of the plurality of release units are connected to the input ends of the respective connection phases;

[0036] The second end of the release resistor is grounded.

[0037] In some embodiments of the present application, when the forced current sharing circuit is in a normal energized state, the current output to the load detected by the current detection unit is normal, and the current detection unit sends a first control signal to the current source;

[0038] The current source receives the first control signal and injects a current of a preset magnitude into the release resistor, so that each release unit maintains the energy stored in the phase connected in parallel with itself.

[0039] In some embodiments of the present application, when the forced current sharing circuit is in an abnormal power-off state, the current output to the load detected by the current detection unit is abnormal, and the current detection unit sends a second control signal to the current source;

[0040] The current source receives the second control signal and reduces the magnitude of the current injected into the release resistor, so that each release unit releases the energy stored in the phase connected in parallel with itself.

[0041] In some embodiments of the present application, a current source injects a current of a preset magnitude into multiple release resistors, and the voltage magnitude at the first end of the release resistor is equal to the voltage magnitude at the first end of all phases in the multi-phase coupling device, so that each release unit maintains the energy stored in the phase in parallel with itself.

[0042] In some embodiments of the present application, the current source reduces the magnitude of the current injected into the multiple release resistors, so that the voltage magnitude of the first end of the release resistor is smaller than the voltage magnitude of the first end of all phases in the multi-phase coupling device, so that each release unit releases the energy stored in the phase connected in parallel with itself.

[0043] In some embodiments of the present application, the forced current sharing circuit further includes: a precision resistor;

[0044] The second ends of all phases in the multiphase coupling device are connected in parallel to the first end of the precision resistor, and the second end of the precision resistor is connected to the input end of the load;

[0045] The current detection unit uses a precision resistor to detect the current output to the load, and generates a corresponding control signal according to whether the current is normal or abnormal, and sends it to the current source.

[0046] In some embodiments of the present application, the release unit includes: a diode;

[0047] The anode of the diode is connected to the input terminal of the parallel-connected phase;

[0048] The cathode of the diode is connected to the positive terminal of the current source and the first end of the release resistor respectively.

[0049] In some embodiments of the present application, the current source includes: a voltage-controlled current source.

[0050] A second aspect of an embodiment of the present application provides a chip, the power supply structure of the chip adopts any forced current sharing circuit as described in the first aspect.

[0051] A third aspect of the embodiments of the present application provides a mainboard, the mainboard comprising any forced current sharing circuit as described in the first aspect;

[0052] The forced current sharing circuit is used to force the output current of the power supply end in the motherboard to be shared to meet the power supply current requirements of the chips in the motherboard.

[0053] A fourth aspect of the embodiments of the present application provides an electronic device, the electronic device comprising any forced current sharing circuit as described in the first aspect;

[0054] The forced current sharing circuit is used to force the output current of the power supply terminal of the motherboard of the electronic device to meet the power supply current requirements of the chip in the motherboard.

[0055] The forced current sharing circuit provided in the present application includes: a multiphase coupling device and multiple current channels connected in parallel; the first end of each phase in the multiphase coupling device is connected to the output end of a current channel; the second end of each phase in the multiphase coupling device is connected in parallel with the second ends of other phases and then connected to a load.

[0056] Because the coupling coefficient and mutual inductance between each two phases in a multiphase coupled device are 1, they are fully coupled and have no magnetic leakage. Therefore, when the current flowing through any one phase changes, the currents in all other phases also change simultaneously, ensuring that the currents at the first and second terminals of each phase in the multiphase coupled device are equal to those at the first and second terminals of the other phases.

[0057] The forced current sharing circuit proposed in this application can actively force current sharing, avoiding the problem that individual Efuses exceed the working limit and stop working due to overcurrent and overheating due to different current flow caused by Efuse manufacturing process or product batch. The current flowing through all Efuses is not excessive, so there will naturally be no overheating problem, and there will be no problem of causing surrounding devices to fail together, thus avoiding accidents such as heat damage and improving the stability of board operation.

[0058] Moreover, the forced current sharing circuit proposed in this application does not add any additional control logic or control circuit, and the circuit structure is simple. Moreover, due to the use of passive components alone, it is not prone to errors. While improving the power cycle and efficiency of the forced current sharing circuit, the reliability of the forced current sharing circuit is also improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without any creative work.

[0060] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments of the present application. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0061] FIG1 is a schematic diagram of the operating current waveform under the current conventional chip power supply structure;

[0062] Figure 2 is a schematic diagram of a conventional chip power supply structure;

[0063] FIG3 is a modular schematic diagram of a forced current sharing circuit according to an embodiment of the present application;

[0064] FIG4 is a modular schematic diagram of a forced current sharing circuit using a multi-phase coupled transformer as an example in an embodiment of the present application;

[0065] FIG5 is a structural diagram of a forced current sharing circuit in an embodiment of the present application;

[0066] FIG6 is a schematic structural diagram of an exemplary three-phase coupling transformer in an embodiment of the present application;

[0067] FIG7 is a schematic diagram of a forced current sharing circuit simulation test under a dynamic load condition in an embodiment of the present application;

[0068] FIG8 is a circuit structure corresponding to FIG7 in an embodiment of the present application, with a current waveform curve diagram of the current flowing through the front-end circuit of the two-phase coupling transformer at the same time;

[0069] FIG9 is a block diagram of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0070] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0071] Currently, PCB boards are designed with EFuses (electronic fuses) of different voltage levels to ensure a stable power supply. Due to the increase in current, multi-phase EFuses are usually connected in parallel during design to ensure current flow capacity.

[0072] Unlike traditional thermal fuses, electronic fuses (Efuse) detect current by measuring the voltage across a known resistor. The load current passes through a field-effect transistor (Metal-Oxide-Semiconductor, MOS) and a detection resistor and is monitored by the voltage across the detection resistor. When this voltage exceeds a preset value, the control logic disconnects the MOS and cuts off the current path, shutting off the current. Because the MOS is connected in series with the power line and the load, it must have a very low on-resistance so that it does not cause excessive current resistance (IR) drop or power loss. Electronic fuses (Efuse) have characteristics, flexibility, and functions that thermal fuses cannot achieve.

[0073] The inventors further discovered that due to manufacturing process or product batch reasons, it is impossible to guarantee that each Efuse or MOS has the same Rdson (on-resistance) when turned on. Existing Efuses all operate in the saturation region, that is, under heavy load and high current conditions, the on-resistance Rdson of the MOS in the Efuse is uncontrollable. Rdson is only related to the manufacturing process and material properties, and it cannot be guaranteed that the current flowing through each Efuse or MOS is the same. In actual high-current scenarios, the current changes at all times and is irregular and unpredictable, and the current rise slope is also unpredictable. The operating current waveform diagram is shown in Figure 1: the horizontal axis is time T, in milliseconds (ms), and the vertical axis is current I, in amperes (A). It can be seen that the current changes are irregular and unpredictable.

[0074] From the formula power P = △U * I, we know that △U = Uvin - Uvout, where Uvin represents the input voltage and Uvout represents the output voltage. Ideally, the input and output voltages of multiple parallel EFuses are identical. However, due to differences in Rdson, the current flowing through each EFuse varies. An EFuse with a higher current draw generates more heat than other EFuses. If this heat accumulates and exceeds the EFuse's operating limit, overcurrent and overheating can disrupt EFuse operational stability. If a particular EFuse ceases to operate, the other parallel EFuses will assume its load current, further deteriorating operational conditions and potentially causing surrounding components to fail, risking board burnout.

[0075] Taking the current conventional chip power supply structure as an example, referring to the circuit structure shown in Figure 2, a 54V power input terminal 101 inputs a 54V voltage, and a 54V separate EFuse unit 102 protects the 54V bus. Figure 2 exemplarily shows three 54V MOS transistors and a 54V electronic fuse control unit 1021 to represent the 54V separate EFuse unit 102.

[0076] The 54V separate EFuse 102 outputs a 54V voltage, which is converted to a 12V voltage by a 4:1 voltage conversion module 106. The 12V voltage then passes through the 12V integrated EFuse 103 to protect the 54V bus. Figure 2 shows five low-voltage EFuse structures 1031 to represent the 12V integrated EFuse 103. The 12V voltage is regulated by the VR (voltage regulation) unit 104 to generate the operating voltage required by the CPU chip 105, for example, 1.3V, which is then output to the CPU chip 105.

[0077] In the above circuit structure, both the 54V separate EFuse unit 102 and the 12V integrated EFuse unit 103 are designed to achieve passive current sharing of the multi-phase EFuses solely through wiring layout, and the operating current state of each EFuse in actual application cannot be predicted.

[0078] When an EFuse has different parameters, for example, the top EFuse in the 12V integrated EFuse unit 103 has different parameters from the other EFuses, its Rdson is smaller when the top EFuse is turned on, and the current flowing through it will increase. As the current increases, its Rdson will increase due to the increase in temperature, causing the current to decrease, thereby achieving passive current sharing. When the temperature of the top EFuse rises to exceed the operating limit, it will stop working, and the other four EFuses in parallel will need to bear its load current, causing the entire operating condition to further deteriorate, and even cause surrounding components to fail, such as capacitor failure and fire, and ultimately bring the risk of burning the entire board.

[0079] To address the above problem, how to actively force the output current of the circuit to be the same and achieve balance when the current flowing through each circuit path is different? The embodiment of the present application proposes a forced current sharing circuit. The forced current sharing circuit of the present application is described in detail below.

[0080] The forced current sharing circuit proposed in the present application includes: a multiphase coupling device and multiple current channels connected in parallel; the first end of each phase in the multiphase coupling device is connected to the output end of a current channel; the second end of each phase in the multiphase coupling device is connected in parallel with the second ends of other phases and then connected to a load; wherein the coupling coefficient and mutual inductance between each two phases in the multiphase coupling device are both 1, so that the current at the first and second ends of each phase in the multiphase coupling device is equal to the current at the first and second ends of other phases.

[0081] The above structure can be better understood by exemplifying the modular schematic diagram of the forced current sharing circuit shown in FIG3 . FIG3 includes: multiple current channels 201, 202, 203, etc. connected in parallel. The first end of each phase 301, 302, 303, etc. in the multi-phase coupling device 300 is connected to the output end of a current channel. For example, as shown in FIG3 , the first phase 301 is connected to the first current channel 201, and the second phase 302 is connected to the second current channel 202.

[0082] The second ends of all phases are connected in parallel and then connected to the load 400 , for example, as shown in FIG3 : the second end of the first phase 301 , the second end of the second phase 302 , and the second end of the third phase 303 are connected in parallel and then connected to the load 400 .

[0083] Because the coupling coefficient and mutual inductance between each two phases in the multiphase coupling device are both 1, they are fully coupled and have no magnetic leakage. Therefore, when the current flowing through any phase changes—for example, due to a difference in the Rdson of the Efuse, causing the current transmitted through the second current channel 202 to change, and the current flowing through the second phase 302 to change—the currents in all other phases 301, 303, ... will also change simultaneously, thereby making the currents at the first and second ends of each phase 301, 303, ... in the multiphase coupling device equal to those at the first and second ends of the other phases, achieving active forced current sharing.

[0084] In addition, the forced current sharing circuit proposed in this application does not add any control logic or control circuit. It only adds multi-phase coupling devices on the basis of the existing circuit structure. The overall circuit structure is simple, and due to the use of passive components, it is not prone to errors. While improving the power cycle and efficiency of the forced current sharing circuit, the reliability of the forced current sharing circuit is also improved.

[0085] In some embodiments of the present application, the multi-phase coupling device may include: a multi-phase coupling transformer or a multi-phase coupling inductor.

[0086] In a multiphase coupled transformer, all phase windings share a common magnetic core. Each pair of phase windings is opposite-terminal coupled, and the coupling coefficient and mutual inductance between the two phase windings are both 1. The first end of each phase winding in the multiphase coupled transformer is connected to the output of a current channel.

[0087] The second end of each phase winding coil in the multi-phase coupling transformer is connected in parallel with the second ends of other phase winding coils and then connected to the load, and the first end of the n-1th phase winding coil and the second end of the nth phase winding coil are the same-named ends, where n≥2.

[0088] Similarly, in a multiphase coupled inductor, all phases share a common magnetic core. Each pair of inductors in the multiphase coupled inductor is coupled with opposite-terminal terminals, and the coupling coefficient and mutual inductance between the two phases are both 1. The first terminal of each phase inductor is connected to the output terminal of a current channel.

[0089] The second end of each phase inductor in the multi-phase coupled inductor is connected in parallel with the second ends of the other phase inductors and then connected to the load, and the first end of the n-1th phase inductor and the second end of the nth phase inductor are the same end, where n≥2.

[0090] The above structure can be better understood by exemplifying the modular schematic diagram of a forced current sharing circuit using a multi-phase coupled transformer as an example, as shown in FIG4 . FIG4 uses three phases as an example, and the remaining structure is the same as FIG3 . The first end of winding coil A of the first phase 301 is connected to the output end of the first current channel 201, the first end of winding coil B of the second phase 302 is connected to the output end of the second current channel 202, and the first end of winding coil C of the third phase 303 is connected to the output end of the second current channel 203.

[0091] The second end of winding coil A, the second end of winding coil B, and the second end of winding coil C are connected in parallel and connected to load 400. The first end of winding coil A and the second end of winding coil B are the same end, the first end of winding coil B and the second end of winding coil C are the same end, and the first end of winding coil C and the second end of winding coil A are the same end.

[0092] Since the coupling coefficient and mutual inductance between each two-phase winding coils in a multiphase coupled transformer are both 1, or the coupling coefficient and mutual inductance between each two-phase inductor coils in a multiphase coupled inductor are both 1, it can be known from the mutual inductance calculation formula that: the self-inductance of each phase winding coil in the multiphase coupled transformer is the same; or the self-inductance of each phase inductor coil in the multiphase coupled inductor is the same.

[0093] Taking a two-phase winding coil or a two-phase inductor coil as an example, the mutual inductance calculation formula is:

[0094] In the above formula, M represents mutual inductance, K represents the coupling coefficient, L1 represents the self-inductance of one phase winding or inductor, and L2 represents the self-inductance of the other phase winding or inductor. Similarly, it can be deduced that the self-inductance of n-phase windings or inductors remains consistent.

[0095] When the forced current sharing circuit is in a dynamic working state, when the current in the current channel connected to any phase changes, the other phases all induce electromotive force, so that the current output to the load changes at the same time, thereby making the current at the first end and the second end of each phase equal.

[0096] When the forced current-sharing circuit is in a static working state, the existence of the coil DC resistance DCR of each phase in the multi-phase coupling device increases the loop impedance of the current channel connected to it, and the increase in loop impedance can passively adjust and reduce the uneven current ratio of multiple current channels. In addition, the increase in loop impedance is also conducive to preventing the current channel from reaching the power limit, that is, preventing it from reaching the so-called power limit. It should be noted that the so-called dynamic working state refers to a state in which the load of the forced current-sharing circuit continues to change, causing its working current to continue to change, and the so-called static working state refers to a state in which the load of the forced current-sharing circuit remains unchanged and the working current does not change.

[0097] In some embodiments of the present application, the forced current sharing circuit further includes: multiple electronic fuses, i.e., multiple Efuses. One electronic fuse Efuse is arranged in one current channel. The number of electronic fuses Efuses is equal to the number of current channels.

[0098] Based on this circuit structure, the first end of each phase in a multiphase coupling device can be directly connected to the output of an electronic fuse (Efuse). The input of each Efuse receives the current output from the preceding circuit. The second end of each phase in the multiphase coupling device is connected in parallel with the second ends of the other phases and then connected to the load. Taking the current conventional chip power supply structure as an example, the input end of each Efuse receives the current transmitted by the 12V voltage line, and its output end is connected to a phase in the multiphase coupling device.

[0099] In some embodiments of the present application, considering that the reverse voltage shock existing when the board loses power may damage the subsequent structure or components after the second ends of all phases in the multi-phase coupling device are connected in parallel, the forced current sharing circuit also includes: a current detection unit, a current source, a release resistor and multiple release units.

[0100] The current detection unit is connected to the current source and is used to detect the current output to the load, that is, to detect the current output after the second ends of all phases in the multi-phase coupling device are connected in parallel; the current detection unit is also used to send a control signal to the current source based on the detected current output to the load.

[0101] The current source is connected to multiple release units and release resistors respectively, and is used to inject currents of different sizes into the release resistors according to the control signal; each release unit is connected in parallel with a phase in the multi-phase coupling device, and each release unit is used to release or maintain the energy stored in the parallel phase with itself according to the size of the current injected into the release resistor.

[0102] For example, consider a multiphase coupled transformer as a multiphase coupled device. Each release unit is connected in parallel with a phase winding in the multiphase coupled transformer. Each release unit is designed to release or retain the energy stored in the phase winding connected in parallel to it, depending on the magnitude of the current injected into the release resistor. The connection relationship for the inductor coil can be deduced similarly, so this will not be further elaborated.

[0103] In terms of specific structure, the negative terminal of the current source is grounded, while the positive terminal is connected to the second terminals of each of the multiple release units and the first terminal of the release resistor. The second terminal of the release resistor is grounded. The first terminal of each of the multiple release units is connected to the input terminal of the phase to which it is connected. For example, in a multiphase coupling device such as a multiphase coupling transformer, the first terminal of each release unit is connected to the input terminal of the phase winding to which it is connected, i.e., the terminal connected to the current channel.

[0104] In some embodiments of the present application, the current detection unit can use various currently known methods to detect the current output to the load. A preferred method is to use precision resistors to detect the current output to the load. Therefore, the forced current sharing circuit also includes: precision resistors. In terms of specific structure:

[0105] The second ends of all phases in the multi-phase coupling device are connected in parallel to the first end of the precision resistor, and the second end of the precision resistor is connected to the input end of the load; that is, the precision resistor is located in the output current channel after the second ends of all phases are connected in parallel. This is conducive to the current detection unit using the precision resistor to accurately detect the current output to the load.

[0106] After the current detection unit uses a precision resistor to accurately detect the current output to the load, it generates a corresponding control signal based on whether the current is normal (i.e., the board power supply is normal) or abnormal (i.e., the board power supply is abnormal or power is off) and sends it to the current source.

[0107] In some embodiments of the present application, the release unit can use various currently known circuit structures or components to maintain or release the energy stored in the parallel phase with itself. A preferred method is to use a diode. Therefore, the release unit includes: a diode; specifically, the structure:

[0108] The anode of the diode is connected to the input end of the parallel connection phase; the cathode of the diode is connected to the positive terminal of the current source and the first end of the release resistor respectively.

[0109] In some embodiments of the present application, the current source can use various currently known current source structures to inject a preset current into the release resistor or reduce the injected current. A preferred method is to use a voltage-controlled current source (VCCS). Therefore, the current source includes: a voltage-controlled current source. Generally, a simpler voltage-controlled current source can be composed of a resistor and a transistor, where the transistor base receives a control signal, the collector is grounded, and the emitter is connected to the release resistor.

[0110] In order to better explain and illustrate the above-mentioned forced current sharing circuit, a structural diagram of a forced current sharing circuit is shown in Figure 5. In Figure 5, a multi-phase coupling device adopts a three-phase coupling transformer (three-phase transformer coils LA, LB, LC), three Efuse units 501 are arranged on three current channels, a current source adopts a voltage-controlled current source 502, and a release unit adopts a diode 505 as an example.

[0111] Voltage busbar 503 implements current protection via three Efuse units 501. The output end of each Efuse unit 501 is connected to the first end of each of the three-phase transformer coils LA, LB, and LC, and the first end of each of the three diodes D. The first end of the three-phase transformer coil LA is exemplarily represented by a black solid circle, and the second end is exemplarily represented by a black solid pentagon; the first end of LB is exemplarily represented by a black solid diamond, and the second end is exemplarily represented by a black solid circle; the first end of LC is exemplarily represented by a black pentagon, and the second end is exemplarily represented by a black solid diamond. This shows that each pair of phase windings in the three examples are opposite-terminal coupled, and the coupling coefficient and mutual inductance between each pair of phase windings are both 1, and the self-inductance is also consistent.

[0112] The second ends of the three-phase transformer coils LA, LB, and LC are connected in parallel to the first end of the precision resistor 504 , and the second end of the precision resistor 504 is connected to the load 400 .

[0113] The second end of each of the three diodes 505 is connected to the positive terminal of the voltage-controlled current source 502 and the first end of the release resistor 507 respectively. The negative terminal of the voltage-controlled current source 502 is grounded, and the second end of the release resistor 507 is grounded.

[0114] The current detection unit 506 detects the current output to the load 400 using the precision resistor 504 , and sends a control signal to the voltage-controlled current source 502 according to the detected current output to the load 400 .

[0115] When the forced current sharing circuit is in dynamic operation and in a normal energized state (meaning the power supply is normal), the current output to the load 400 detected by the current detection unit 506 is normal. The current detection unit 506 sends a first control signal to the voltage-controlled current source 502. The voltage-controlled current source 502 receives the first control signal and injects a preset current into the release resistor 507, so that each diode 505 retains the energy stored in the transformer coil connected in parallel with itself. The voltage-controlled current source 502 injects a preset current into the multiple release resistors 507, so that the voltage at the first end of the release resistor 507 is equal to the voltage at the first end of the transformer coils of all phases in the multi-phase coupled transformer. This allows each release unit to retain the energy stored in parallel with itself.

[0116] For example, if the bus voltage is 12V, the voltage-controlled current source 502 injects a preset current into the release resistor 507, so that the voltage at the first end of the release resistor 507 is also maintained at approximately 12V (which can float within the allowable error range), which is equal to the voltage at the first end of each transformer coil. In this way, each diode 505 can maintain the energy stored in the transformer coil connected in parallel with itself.

[0117] At the same time, when the current flowing through a certain Efuse changes, since the coupling coefficient and mutual inductance between each two-phase transformer coils in the multi-phase coupled transformer are 1, the remaining phase transformer coils all induce electromotive force, causing the current output to the load to change simultaneously, thereby making the current at the first end and the second end of each phase transformer coil equal.

[0118] When the forced current sharing circuit is in an abnormal power-off state (i.e., a power supply abnormality or no power supply), the current detection unit 506 detects an abnormal current output to the load 400. The current detection unit 506 sends a second control signal to the voltage-controlled current source 502. The voltage-controlled current source 502 receives the second control signal and reduces the current injected into the release resistor 507, thereby causing each diode 505 to release energy stored in the transformer coil connected in parallel with the diode. When the voltage-controlled current source 502 reduces the current injected into the release resistor 507, the voltage at the first end of the release resistor 507 becomes lower than the voltage at the first end of all phase transformer coils in the multi-phase coupled transformer. This allows each diode 505 to release energy stored in the transformer coil connected in parallel with the diode.

[0119] For example, if the bus voltage is 12V, then when a disconnection anomaly occurs, voltage-controlled current source 502 reduces the current injected into release resistor 507, causing the voltage at the first end of release resistor 507 to fall below 12V, which is lower than the voltage at the first end of each transformer coil. Since the bus voltage drops slowly due to the presence of capacitors in the circuit, the anode voltage of diode 505 will be greater than the cathode voltage, causing each diode 505 to conduct. This allows each diode 505 to release the energy stored in the transformer coil connected in parallel with it, preventing the reverse electromotive force generated by E (back electromotive force) = -L (inductance) di / dt from damaging subsequent circuit structures or components.

[0120] As for the current sharing effect when the forced current sharing circuit is in a static working state, it was tested with the current conventional chip power supply structure and found that the on-resistance Rdson in the Efuse is almost the same in the static working state, most of which are 1 milliohm, so there is naturally no need for active current sharing.

[0121] Furthermore, the DC resistance (DCR) of each phase in a multiphase coupled transformer increases the loop impedance of the current path connected to it. This increased loop impedance can passively adjust and reduce the uneven current ratio among multiple current paths. Furthermore, the increased loop impedance helps prevent the current path from reaching its power limit, commonly known as the power limit.

[0122] For example, if the self-inductance of a three-phase coupling transformer is 400uH, the DC resistance (DCR) of the coil is 0.25mohm, and a single-phase current of 50A is used, the line voltage drop increases by only 12.5mV due to the presence of the coupling transformer coil (which can be considered an inductor coil), which is negligible for a 12V bus or 13.5V bus.

[0123] At the same time, using two phases in parallel for Efuse calculation, assuming an Rdson of 1 milliohm for one phase and 0.5 ohm for the other, adding a three-phase coupling transformer can increase the loop impedance with a smaller Rdson, preventing the power limit from being reached. The current ratio of the two phases is also adjusted from 1:2 to 3:5. The addition of the three-phase coupling transformer also reduces the current imbalance in the purely static operating circuit.

[0124] For example, FIG6 shows a schematic structural diagram of an exemplary three-phase coupled transformer, in which the three-phase coils share a common magnetic core; each two-phase winding coils are coupled with opposite-end terminals, and the coupling coefficient and mutual inductance between each two-phase winding coils are both 1.

[0125] In some embodiments of the present application, if the multi-phase coupling device adopts a multi-phase coupled inductor, the multi-phase coupled inductor can be preferably composed of a small inductor with the inductor model: CTX17-18765-R. The current detection unit can preferably be a digital current monitoring chip, for example, a chip with a high sampling rate, fast response speed, and support for I2C communication or SPI communication protocol: model: INA226. The electronic fuse Efuse can preferably have a 50A current specification, an on-resistance Rdson of 1 milliohm, and a model: MP5991. The voltage-controlled current source is preferably a combination of a resistor and a transistor, and the voltage-controlled current source model is: LMBT3904DW1T1G. Of course, the above are only preferred components and their models, and all other circuit structures or components that can achieve the above functions can be replaced.

[0126] In order to verify the effectiveness of the forced current sharing circuit proposed in this application, a simulation test was carried out based on a forced current sharing circuit under the dynamic load condition shown in FIG7 . A certain frequency was selected in the simulation, and another heavy load was connected in parallel to the existing load, wherein the existing loads were all 1 milliohm, and the added heavy loads were all 100 milliohms. The resistance representing the on-resistance Rdson of the electronic fuse Efuse was set to 2 milliohms, 1 milliohms, 10 milliohms, and 1 milliohms, respectively. The bus voltage was 12V, the bus current was 23.9A (amperes), and the gate voltage of the control MOS tube was 13.5V.

[0127] As shown in Figure 7, the simulation results show that the input currents of the upper coil without coupling transformer are 5.1A and 6.8A respectively. The lower coil with two-phase coupling transformer has input currents of 6A and 6A respectively.

[0128] Through simulation tests and analog oscilloscopes, it can be concluded that under dynamic load conditions, at the same time, the current waveforms flowing through the rear-end circuits of the coupling transformers almost completely overlap (the current scales are consistent). Referring to the current waveform curve shown in Figure 8, Figure 8 shows the current waveform curve flowing through the front-end circuits with two-phase coupling transformer coils (each with an input current of 6A and 6A).

[0129] As can be seen from the analog oscilloscope in Figure 8, at 1.222ms, the current value is 6A, and the currents of the two lines are almost the same at the same time. In contrast, the two-phase currents of the transformer coil without two-phase coupling are 5.1A and 6.8A respectively, indicating no current sharing. This verifies that the forced current sharing effect of this application is significant.

[0130] In addition, based on the above explanation and description of the forced current sharing circuit proposed in this application and its circuit structure and principle, those skilled in the art can easily know that: the forced current sharing circuit proposed in this application is not only applicable to the field of integrated circuits, but can also be expanded to other low voltage, high voltage, power grid or mains power supply application scenarios with similar active forced current sharing requirements. For example: the currently widely promoted distributed new energy power grid can add the above-mentioned multi-phase coupling device, as well as current detection unit, current source, release resistor and multiple release units at the current output end of each line to achieve active forced current sharing, so as to continuously optimize the power supply structure.

[0131] Based on the above-mentioned forced current sharing circuit, an embodiment of the present application further proposes a chip, the power supply structure of the chip adopts any of the above-mentioned forced current sharing circuits.

[0132] Based on the above forced current sharing circuit, an embodiment of the present application further provides a mainboard, which includes any of the above forced current sharing circuits;

[0133] The forced current sharing circuit is used to force the output current of the power supply end in the motherboard to be shared to meet the power supply current requirements of the chips in the motherboard.

[0134] Based on the above forced current sharing circuit, an embodiment of the present application further provides an electronic device, as shown in FIG9 , the electronic device includes any of the above forced current sharing circuits 901;

[0135] The forced current sharing circuit 901 is used for forced current sharing of the output current of the power supply terminal of the mainboard 902 in the electronic device to meet the power supply current demand of the chip in the mainboard 902.

[0136] Through the above examples, the forced current sharing circuit provided in the present application includes: a multi-phase coupling device and multiple current channels connected in parallel; the first end of each phase in the multi-phase coupling device is connected to the output end of a current channel; the second end of each phase in the multi-phase coupling device is connected in parallel with the second ends of other phases and then connected to the load.

[0137] Because the coupling coefficient and mutual inductance between each two phases in a multiphase coupled device are 1, they are fully coupled and have no magnetic leakage. Therefore, when the current flowing through any one phase changes, the currents in all other phases also change simultaneously, ensuring that the currents at the first and second terminals of each phase in the multiphase coupled device are equal to those at the first and second terminals of the other phases.

[0138] The forced current sharing circuit proposed in this application can actively force current sharing, avoiding the problem that individual Efuses exceed the working limit and stop working due to overcurrent and overheating due to different current flow caused by Efuse manufacturing process or product batch. The current flowing through all Efuses is not excessive, so there will naturally be no overheating problem, and there will be no problem of causing surrounding devices to fail together, thus avoiding accidents such as heat damage and improving the stability of board operation.

[0139] Moreover, the forced current sharing circuit proposed in this application does not add any additional control logic or control circuit, and the circuit structure is simple. Moreover, due to the use of passive components alone, it is not prone to errors. While improving the power cycle and efficiency of the forced current sharing circuit, the reliability of the forced current sharing circuit is also improved.

[0140] Although preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they become aware of the basic inventive concepts. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the embodiments of the present invention.

[0141] Finally, it should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or terminal device that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or terminal device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article, or terminal device that includes the element.

[0142] The embodiments of the present application are described above in conjunction with the accompanying drawings, but the present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of this application, ordinary technicians in this field can also make many forms without departing from the purpose of this application and the scope of protection of the claims, all of which are protected by this application.

Claims

1. A forced current sharing circuit, characterized in that: The forced current sharing circuit comprises: a multi-phase coupling device and a plurality of current channels connected in parallel; The first end of each phase in the multi-phase coupling device is connected to the output end of a current channel; The second end of each phase in the multiphase coupling device is connected in parallel with the second ends of other phases and then connected to the load; The coupling coefficient and mutual inductance between each two phases in the multiphase coupling device are both 1, so that the current at the first end and the second end of each phase in the multiphase coupling device are equal to the current at the first end and the second end of other phases.

2. The forced current sharing circuit according to claim 1, characterized in that: The multiphase coupling device includes: a multiphase coupling transformer or a multiphase coupling inductor; All phase winding coils in the multi-phase coupling transformer share a magnetic core; Each two-phase winding coil in the multi-phase coupling transformer is coupled with opposite-end winding, and the coupling coefficient and mutual inductance between each two-phase winding coil are 1; or, All phase inductance coils in the multi-phase coupled inductor share a magnetic core; In the multi-phase coupled inductor, each two-phase inductor coils are coupled with opposite-end terminals, and the coupling coefficient and mutual inductance between each two-phase inductor coils are both 1.

3. The forced current sharing circuit according to claim 2, characterized in that: A first end of each phase winding coil in the multi-phase coupling transformer is connected to an output end of a current channel; The second end of each phase winding coil in the multi-phase coupling transformer is connected in parallel with the second ends of other phase winding coils and then connected to the load, and the first end of the n-1th phase winding coil and the second end of the nth phase winding coil are the same end, wherein n≥2; or The first end of each phase inductor coil in the multi-phase coupled inductor is connected to the output end of a current channel; The second end of each phase inductor in the multi-phase coupled inductor is connected in parallel with the second ends of other phase inductors and then connected to the load, and the first end of the n-1th phase inductor and the second end of the nth phase inductor are the same end, where n≥2.

4. The forced current sharing circuit according to claim 2, characterized in that: The coupling coefficient and mutual inductance between each two-phase winding coil in the multi-phase coupling transformer are both 1, and the self-inductance of each phase winding coil is the same; or, The coupling coefficient and mutual inductance between each two-phase inductor coils in the multi-phase coupled inductor are both 1, and the self-inductance of each phase inductor coil is the same.

5. The forced current sharing circuit according to claim 1, characterized in that: When the forced current sharing circuit is in a dynamic working state, when the current of the current channel connected to any phase changes, the other phases all induce electromotive forces. This allows the current output to the load to change simultaneously, thereby making the current at the first end and the current at the second end of each phase equal.

6. The forced current sharing circuit according to claim 1, characterized in that: When the forced current sharing circuit is in a static working state, each phase in the multi-phase coupling device increases the loop impedance of the current channel connected thereto, passively adjusting and reducing the uneven current ratio of the multiple current channels.

7. The forced current sharing circuit according to claim 1, characterized in that: When the forced current sharing circuit is in a static working state, each phase in the multi-phase coupling device increases the loop impedance of the current channel connected thereto to prevent the power limit from being reached.

8. The forced current sharing circuit according to claim 1, characterized in that: The forced current sharing circuit further includes: a plurality of electronic fuses, one electronic fuse being arranged in one current channel; The first end of each phase in the multi-phase coupling device is connected to the output end of an electronic fuse, and the input end of each electronic fuse receives the current output by the previous stage circuit; The second end of each phase in the multi-phase coupling device is connected in parallel with the second ends of other phases and then connected to the load.

9. The forced current sharing circuit according to claim 1, characterized in that: The forced current sharing circuit further includes: a current detection unit, a current source, a release resistor and a plurality of release units; The current detection unit is connected to the current source, and is used to detect the current output to the load, and send a control signal to the current source according to the detected current output to the load; The current source is connected to the plurality of release units and the release resistors respectively, and is used to inject currents of different magnitudes into the release resistors according to the control signal; One of the release units is connected in parallel with one phase of the multi-phase coupling device, and is used to release or maintain the energy stored in the phase connected in parallel with itself according to the magnitude of the current injected into the release resistor.

10. The forced current sharing circuit according to claim 9, characterized in that: The negative terminal of the current source is grounded, and the positive terminal is connected to the second terminals of the plurality of release units and the first terminal of the release resistor respectively; The first ends of the plurality of release units are respectively connected to the input ends of the respective connection phases; The second end of the release resistor is grounded.

11. The forced current sharing circuit according to claim 9, characterized in that: When the forced current sharing circuit is in a normal energized state, the current output to the load detected by the current detection unit is normal, and the current detection unit sends a first control signal to the current source; The current source receives the first control signal and injects a current of a preset magnitude into the release resistor, so that each of the release units maintains the energy stored in the phase connected in parallel with itself.

12. The forced current sharing circuit according to claim 9, characterized in that: When the forced current sharing circuit is in an abnormal power-off state, the current output to the load detected by the current detection unit is abnormal, and the current detection unit sends a second control signal to the current source; The current source receives the second control signal and reduces the magnitude of the current injected into the release resistor, so that each of the release units releases the energy stored in the phase connected in parallel with itself.

13. The forced current sharing circuit according to claim 11, characterized in that: The current source injects a current of a preset magnitude into the plurality of release resistors, and the voltage magnitude at the first end of the release resistor is equal to the voltage magnitude at the first end of all phases in the multi-phase coupling device, so that each release unit maintains the energy stored in the phase connected in parallel with itself.

14. The forced current sharing circuit according to claim 12, characterized in that: The current source reduces the magnitude of the current injected into the multiple release resistors, so that the voltage magnitude of the first end of the release resistor is smaller than the voltage magnitude of the first end of all phases in the multi-phase coupling device, so that each release unit releases the energy stored in the phase connected in parallel with itself.

15. The forced current sharing circuit according to claim 9, characterized in that: The forced current sharing circuit further includes: a precision resistor; The second ends of all phases in the multi-phase coupling device are connected in parallel to the first end of the precision resistor, and the second end of the precision resistor is connected to the input end of the load; The current detection unit detects the current output to the load using the precision resistor, generates a corresponding control signal according to whether the current is normal or abnormal, and sends the control signal to the current source.

16. The forced current sharing circuit according to any one of claims 9 to 14, characterized in that: The release unit includes: a diode; The anode of the diode is connected to the input terminal of the parallel-connected phase; The cathode of the diode is connected to the positive terminal of the current source and the first end of the release resistor respectively.

17. The forced current sharing circuit according to any one of claims 9 to 15, characterized in that: The current source includes: a voltage-controlled current source.

18. A chip, characterized in that: The power supply structure of the chip adopts the forced current sharing circuit as described in any one of claims 1-15.

19. A motherboard, characterized in that: The mainboard includes the forced current sharing circuit as described in any one of claims 1 to 15; The forced current sharing circuit is used for forced current sharing of the output current of the power supply terminal in the mainboard to meet the power supply current demand of the chip in the mainboard.

20. An electronic device, characterized in that: The electronic device comprises the forced current sharing circuit as described in any one of claims 1 to 15; The forced current sharing circuit is used for forced current sharing of the output current of the power supply terminal of the mainboard in the electronic device to meet the power supply current demand of the chip in the mainboard.

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