A short - circuit protection and hot - plugging protection circuit and method

Abstract

A short - circuit protection and hot - plugging protection circuit and method. Among them, the circuit includes: a hot - plugging protection unit, a short - circuit protection unit, a load access unit, and first and second switching transistors; the hot - plugging protection unit is used to provide a hot - plugging protection current to the short - circuit protection unit based on the change in the input - end voltage during hot - plugging; the short - circuit protection unit is used to generate a voltage drop of the load access unit based on the hot - plugging protection current during hot - plugging, or is used to generate a voltage drop of the load access unit based on the change in the output - end voltage during a short - circuit; the load access unit is used to provide hot - plugging protection or short - circuit protection for the first and second switching transistors based on the voltage drop of the load access unit generated by it. The method in the present invention is simple and easy to implement, uses a small number of components, saves costs, improves the utilization efficiency of the devices, and at the same time better accommodates the two protection requirements of hot - plugging protection and short - circuit protection.

Description

Technical Field

[0001] The present invention relates to the field of integrated circuits, and more particularly, to a short-circuit protection and hot-swap protection circuit and method. Background Art

[0002] Currently, integrated load switches, as electronic relays used to turn on and off power rails in circuit systems, are widely used in various circuits. Due to the wide application of load switches, the requirements for load switches have also increased. The requirements for load switches in existing circuits are that, when a short circuit occurs, the internal circuit needs to quickly respond to protect the switching transistor, and when a hot-swap operation occurs at the input end, the internal circuit needs to keep the switching transistor in the off state and prevent the energy during the hot-swap operation at the input end from being conducted to the output end through the switching transistor, resulting in damage to the subsequent load. However, there is no load switch circuit in the prior art that can ensure the safety of both hot-swap and short-circuit operations simultaneously.

[0003] In addition, in order to achieve simultaneous protection of hot-swap and short-circuit, the switching transistor structure in the circuit should adopt a bidirectional isolation structure. However, when a short-circuit occurs, the two MOS transistors in the bidirectional isolation structure may conduct, resulting in the voltage across the bidirectional isolation structure losing its isolation.

[0004] Therefore, there is an urgent need for a new type of short-circuit protection and hot-swap protection circuit and method. Summary of the Invention

[0005] To solve the deficiencies in the prior art, the purpose of the present invention is to provide a short-circuit protection and hot-swap protection circuit and method. Through a bidirectional isolation structure, the influence between the output end and the gate of the switching transistor is isolated, and circuit protection can be provided simultaneously when a hot-swap occurs at the load input end and a short-circuit occurs at the load output end.

[0006] The present invention adopts the following technical solutions. In the first aspect of the present invention, it relates to a short-circuit protection and hot-swap protection circuit, which includes: a hot-swap protection unit, a short-circuit protection unit, a load access unit, and first and second switching transistors; wherein, one end of the hot-swap protection unit is connected to the input terminal voltage, and the other end is connected to the short-circuit protection unit, and is used to provide a hot-swap protection current to the short-circuit protection unit based on the change in the input terminal voltage during hot-swap; one end of the short-circuit protection unit is connected to the output terminal voltage, one end is connected to the hot-swap protection unit, and the other end is connected to the load access unit, and is used to generate a voltage drop of the load access unit based on the hot-swap protection current during hot-swap, or is used to generate a voltage drop of the load access unit based on the change in the output terminal voltage during short-circuit; the load access unit is respectively connected to the output terminal voltage, the short-circuit protection unit, and the gates of the first and second switching transistors, and is used to provide hot-swap protection or short-circuit protection for the first and second switching transistors based on the generated voltage drop of the load access unit.

[0007] Preferably, the hot plug protection unit includes a first resistor R3, a first capacitor C3, a switching transistor Mp3, and a first Zener diode D3. One end of the first resistor R3 and the source electrode of the switching transistor Mp3 are respectively connected to the input terminal voltage. The other end of the first resistor R3 and the gate electrode of the switching transistor Mp3 are respectively grounded through the first capacitor C3. The first Zener diode D3 is connected between the gate and source electrodes of the switching transistor Mp3, and the drain electrode of the switching transistor Mp3 is connected to the short circuit protection unit.

[0008] Preferably, the short circuit protection unit includes a second resistor R4, a second capacitor C4, a third capacitor C5, a switching transistor Mn4, a second Zener diode D4, and a third resistor R5. One end of the second resistor R4, the gate electrode of the switching transistor Mn4, and one end of the third capacitor C5 are connected to the hot plug protection unit and are connected to the input terminal voltage through the second capacitor C4. The other end of the second resistor R4 and the source electrode of the switching transistor Mn4 are connected to the output terminal voltage. The other end of the third capacitor C5 is grounded. The second Zener diode D4 is connected between the gate and source electrodes of the switching transistor Mp3. One end of the third resistor R5 is connected to the drain electrode of the switching transistor Mp3, and the other end is connected to the load access unit.

[0009] Preferably, the load access unit includes a switching transistor Mp5, a switching transistor Mp6, a load resistor R6, a third Zener diode D5, a first parasitic diode D6, and a second parasitic diode D7. The source electrodes and gate electrodes of the switching transistor Mp5 and the switching transistor Mp6 are connected to each other and are connected to the short circuit protection unit. The two ends of the load resistor R6 are respectively connected to the source electrode and gate electrode of the switching transistor Mp5 and the switching transistor Mp6. The third Zener diode D5 is respectively connected between the gate and source electrodes of the switching transistor Mp5 and the switching transistor Mp6. The first parasitic diode D6 and the second parasitic diode D7 are respectively connected between the source and drain electrodes of the switching transistor Mp5 and the switching transistor Mp6. The drain electrode of the switching transistor Mp5 is connected to the output terminal current, and the drain electrode of the switching transistor Mp6 is connected to the Gate terminal.

[0010] Preferably, the gate electrodes of the first and second switching transistors are respectively connected to the Gate terminal, the source electrodes are connected to each other, and the drain electrodes are respectively connected to the input terminal voltage and the output terminal voltage.

[0011] Preferably, when a hot plug operation occurs in the circuit, the input terminal voltage increases, the switching transistor Mp3 and the switching transistor Mn4 are sequentially turned on, and a hot plug protection current and a voltage drop of the load access unit are sequentially generated.

[0012] Preferably, when a short circuit occurs in the circuit, the output terminal voltage decreases, the switching transistor Mn4 is turned on, and a voltage drop of the load access unit is generated.

[0013] Preferably, when a hot plugging and unplugging operation occurs in the circuit, the voltage drop of the load access unit causes the switching transistors Mp5 and Mp6 to conduct simultaneously, so as to prevent the first and second switching transistors from conducting due to the hot plugging and unplugging operation.

[0014] Preferably, when a short - circuit operation occurs in the circuit, the voltage drop of the load access unit causes the switching transistors Mp5 and Mp6 to conduct simultaneously, so as to prevent the first and second switching transistors from being broken down due to the short - circuit operation and limit the short - circuit current of the first and second switching transistors.

[0015] In the second aspect of the present invention, a short - circuit protection and hot - plugging protection method is provided, which uses a short - circuit protection and hot - plugging protection circuit as described in the first aspect of the present invention.

[0016] The beneficial effects of the present invention are as follows. Compared with the prior art, the short - circuit protection and hot - plugging protection circuit and method in the present invention utilize a bidirectional isolation structure to isolate the influence between the output end and the gate of the switching transistor, and can simultaneously provide circuit protection when hot plugging and unplugging occur at the load input end and short - circuit occurs at the load output end. The method in the present invention is simple and easy to implement, uses fewer components, saves costs, improves the utilization efficiency of devices, and also better accommodates the two protection requirements of hot - plugging protection and short - circuit protection.

[0017] The beneficial effects of the present invention also include:

[0018] 1) When the voltage at the load output end is greater than the voltage at the load input end, there will be no voltage drop in the load access unit, so the switching transistors in the load access unit will not conduct, thus isolating the voltage value between the gate and the drain of the first and second switching transistors and preventing the drift of the gate voltage of the first and second switching transistors. At this time, the gate of the NMOS switching transistor in the circuit is pulled to the ground potential under the pull - down action of the internal logic control module, thereby preventing the mis - turn - on of the first and second switching transistors.

[0019] 2) When a hot plugging and unplugging operation occurs, the switching transistors in the hot - plugging protection unit, short - circuit protection unit, and load access unit will conduct in sequence. When the voltage at the load input end rises rapidly, the energy coupled from the drain to the gate of Mnpwr1 through the inter - electrode capacitance can be discharged through the conducting MOS transistor in the load access unit, thereby stabilizing the voltage at the Gate end and preventing the conduction of the first and second switching transistors. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a schematic structural diagram of a short - circuit protection circuit in the prior art of the present invention;

[0021] Figure 2 is a schematic structural diagram of a short - circuit protection and hot - plugging protection circuit in the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0022] The present application will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and cannot be used to limit the protection scope of the present application.

[0023] Figure 1 It is a schematic structural diagram of a short - circuit protection circuit in the prior art of the present invention. As Figure 1 shown, a short - circuit protection circuit includes first and second switching transistors. The gates of the first and second switching transistors are connected to each other and connected to the Gate terminal, and the sources are connected to each other. The drain of the first switching transistor is connected to the load input terminal, and the drain of the second switching transistor is connected to the load output terminal.

[0024] It can be understood that the first and second switching transistors shown in Figure 1 should be the switching transistors in the load switch chip, and their function is to realize the connection or disconnection of the load.

[0025] In addition, a protection circuit composed of an NMOS transistor, a parasitic diode, a resistor, a capacitor, etc. is further included in the front stage of the first and second switching transistors. Among them, a Zener diode D1 is connected between the gate and source of the NMOS transistor, a parasitic diode D2 is connected between the source and drain, the source is also connected to the load output terminal, and the drain is also connected to the Gate terminal through a resistor R2. A resistor R1 is connected in parallel at both ends of the Zener diode D1, and the gate of the NMOS transistor is also connected to the load input terminal through a capacitor C1 and grounded through a capacitor C2.

[0026] In this short - circuit protection circuit, the structures of the first and second switching transistors are bidirectional isolation structures. When the voltage at the output terminal of the load is higher than the voltage at the input terminal, for example, the output terminal OUT is at a high voltage and the input terminal IN is 0V. At this time, under the action of the parasitic diode D2 of the NMOS transistor Mn1, the voltage at point A of the drain of the NMOS transistor will be less than the output terminal voltage OUT, and the difference between the voltage at point A and the output terminal voltage OUT should be the voltage drop of the parasitic diode D2. At the same time, since a discharge channel between the Gate terminal and the ground terminal will be opened inside the chip where the circuit is located. Therefore, under the combined action of the voltage drop of the diode D2 and the discharge channel, the voltage of the Gate terminal will be greater than the ground potential and between the output terminal voltage OUT and the ground potential voltage 0V. At this time, due to the magnitude of the voltage of the Gate terminal, it may cause the first and second switching transistors, that is, Figure 1 Mnpwr1 and Mnpwr2 in

[0027] Figure 2This is a schematic diagram of the structure of a short - circuit protection and hot - plug protection circuit in the present invention. As Figure 2 shown, the present invention relates to a short - circuit protection and hot - plug protection circuit. The circuit includes: a hot - plug protection unit, a short - circuit protection unit, a load access unit, and first and second switching transistors. Among them, one end of the hot - plug protection unit is connected to the input - end voltage, and the other end is connected to the short - circuit protection unit, and is used to provide a hot - plug protection current to the short - circuit protection unit based on the change of the input - end voltage during hot - plugging. One end of the short - circuit protection unit is connected to the output - end voltage, one end is connected to the hot - plug protection unit, and the other end is connected to the load access unit, and is used to generate a voltage drop of the load access unit based on the hot - plug protection current during hot - plugging, or is used to generate a voltage drop of the load access unit based on the change of the output - end voltage during a short - circuit. The load access unit is respectively connected to the output - end voltage, the short - circuit protection unit, and the gates of the first and second switching transistors, and is used to provide hot - plug protection or short - circuit protection for the first and second switching transistors based on the voltage drop of the load access unit generated by it.

[0028] It can be understood that the first and second switching transistors shown in Figure 2 should be the switching transistors in the load - switch chip, and their function is to realize the access or disconnection of the load.

[0029] Preferably, the hot - plug protection unit includes a first resistor R3, a first capacitor C3, a switching transistor Mp3, and a first Zener diode D3; one end of the first resistor R3 and the source of the switching transistor Mp3 are respectively connected to the input - end voltage; the other end of the first resistor R3 and the gate of the switching transistor Mp3 are respectively grounded through the first capacitor C3; the first Zener diode D3 is connected between the gate and source of the switching transistor Mp3, and the drain of the switching transistor Mp3 is connected to the short - circuit protection unit.

[0030] Preferably, the short - circuit protection unit includes a second resistor R4, a second capacitor C4, a third capacitor C5, a switching transistor Mn4, a second Zener diode D4, and a third resistor R5; one end of the second resistor R4, the gate of the switching transistor Mn4, and one end of the third capacitor C5 are connected to the hot - plug protection unit and are connected to the input - end voltage through the second capacitor C4; the other end of the second resistor R4 and the source of the switching transistor Mn4 are connected to the output - end voltage; the other end of the third capacitor C5 is grounded; the second Zener diode D4 is connected between the gate and source of the switching transistor Mp3; one end of the third resistor R5 is connected to the drain of the switching transistor Mp3, and the other end is connected to the load access unit.

[0031] Preferably, the load access unit includes a switching transistor Mp5, a switching transistor Mp6, a load resistor R6, a third Zener diode D5, a first parasitic diode D6, and a second parasitic diode D7. The sources and gates of the switching transistors Mp5 and Mp6 are connected to each other and to the short-circuit protection unit. The two ends of the load resistor R6 are respectively connected to the sources and gates of the switching transistors Mp5 and Mp6. The third Zener diode D5 is connected to the gates and sources of the switching transistors Mp5 and Mp6. The first parasitic diode D6 and the second parasitic diode D7 are respectively connected to the source-drain terminals of the switching transistors Mp5 and Mp6. The drain of the switching transistor Mp5 is connected to the output terminal in current connection, and the drain of the switching transistor Mp6 is connected to the Gate terminal.

[0032] Preferably, the gates of the first and second switching transistors are respectively connected to the Gate terminal, the sources are connected to each other, and the drains are respectively connected to the input terminal voltage and the output terminal voltage.

[0033] Preferably, when a hot plugging operation occurs in the circuit, the input terminal voltage rises, and the switching transistors Mp3 and Mn4 are sequentially turned on, and a hot plugging protection current and a voltage drop of the load access unit are sequentially generated. When a hot plugging operation occurs in the circuit, the voltage drop of the load access unit causes the switching transistors Mp5 and Mp6 to be turned on simultaneously to prevent the first and second switching transistors from being turned on due to the hot plugging operation.

[0034] Specifically, when a hot plugging operation occurs in the circuit, the load input terminal voltage, i.e., the IN terminal voltage, rises rapidly. At this time, since the voltage change across the capacitor C3 is slow, a voltage drop is formed across the resistor R3 in the hot plugging protection unit. Since the two ends of the resistor R3 are connected to the gate-source voltage of the switching transistor Mp3, when a voltage drop occurs across the resistor R3, this voltage drop causes the gate-source of the switching transistor Mp3 to conduct. Since a Zener diode D3 is also connected between the gate and source of the switching transistor Mp3, this diode can protect the switching transistor Mp3 to prevent its gate-source voltage from exceeding its own breakdown voltage.

[0035] After the switching transistor Mp3 is turned on, the hot plugging protection unit can generate a hot plugging protection current and output it to the short-circuit protection unit. After the short-circuit protection unit receives the hot plugging protection current generated by the hot plugging protection unit, a part of this current flows through the second resistor R4, and a voltage drop is generated across the second resistor R4, thereby causing the gate-source of the switching transistor Mn4 connected in parallel across the second resistor R4 to conduct. At the same time, the Zener diode D4 protects the switching transistor Mn4 to prevent its gate-source voltage from exceeding its own breakdown voltage.

[0036] When the switch tube Mn4 in the short-circuit protection unit is turned on, the source and drain of the switch tube Mn4 generate current, thereby driving the branch where the source and drain of the switch tube Mn4 are located to generate current. Therefore, starting from the Gate end of the circuit, the current flows through the parasitic diode D7, the load resistor R6, the third resistor R5, and then passes through the switch tube Mn4. Since the current flows through the load resistor R6, a voltage drop is generated, and the voltage drop turns on the switch tubes Mp5 and Mp6.

[0037] In one embodiment of the present invention, the switch tube Mp5 and the switch tube Mp6 can be set to have a larger size, so that their conduction current is also correspondingly larger, so that after being turned on, the branch where the switch tube Mp5 and the switch tube Mp6 are located can establish a low-resistance path between the Gate terminal and the load output terminal. Therefore, during the hot plug action, the increased input terminal IN terminal voltage passes through the parasitic capacitance of the gate-drain electrode of the first switch tube Mnpwr1, and is quickly derived from the branch where the switch tube Mp5 and the switch tube Mp6 are located, thereby avoiding the increase of the Gate terminal voltage.

[0038] Since the first and second switch tubes are easily turned on when the Gate terminal voltage is relatively large, the method of the present invention effectively prevents the first and second switch tubes from being turned on during the hot plug action.

[0039] Preferably, when a short circuit occurs in the circuit, the output voltage decreases, the switch tube Mn4 is turned on, and a voltage drop of the load access unit is generated. When a short circuit occurs in the circuit, the voltage drop of the load access unit causes the switch tubes Mp5 and Mp6 to be turned on at the same time to prevent the first and second switch tubes from being broken down due to the short circuit action, and to limit the short-circuit current of the first and second switch tubes.

[0040] Specifically, when a short circuit occurs in the circuit, the voltage of the load output terminal OUT will drop rapidly. At this time, the voltage of the second capacitor C4 in the short circuit protection unit will not change suddenly, so that a voltage drop occurs across the second resistor R4, and the switch tube Mn4 is turned on. The following process is similar to when a hot plug action occurs in the circuit, and both of them quickly discharge the Gate terminal by establishing a low-resistance path between the Gate terminal and the load output terminal, and reduce the voltage difference between the Gate terminal and the load output terminal. Therefore, the method in the present invention effectively prevents the first and second switch tubes from being broken down when a short circuit occurs in the circuit, and reduces the short-circuit current of the first and second switch tubes.

[0041] When the voltage at the load output terminal is higher than that at the load input terminal, for example, the voltage at the load output terminal OUT is in a high voltage state and the voltage at the load input terminal IN is 0V, Figure 2 In the dual isolation structure shown in FIG, it is assumed that the conduction voltage drop of the first parasitic diode D6 and the second parasitic diode D7 are both V dioWhen the parasitic diode is conducting, the voltage value at point B should be the difference between the output voltage and the conduction voltage, i.e., OUT - V dio .

[0042] When the circuit is in normal operation, the switching transistor Mn4 is in the cut-off state. Therefore, no current flows through the load resistor R6 and the third resistor R5, so the voltages at points A and B are equal. Similarly, the switching transistor Mp3 is also in the cut-off state, and the Gate terminal and the load output terminal OUT are in an open state. Therefore, the two ends are in an isolated state, preventing the first and second switching transistors Mnpwr1 and Mnpwr2 from being accidentally turned on when the load output terminal has a high voltage, thus causing the gate of the switching transistor to drift to a high level.

[0043] The second aspect of the present invention relates to a short-circuit protection and hot-plug protection method, which uses a short-circuit protection and hot-plug protection circuit as described in the first aspect of the present invention.

[0044] The beneficial effects of the present invention are that, compared with the prior art, the short-circuit protection and hot-plug protection circuit and method in the present invention utilize a bidirectional isolation structure to isolate the influence between the output terminal and the gate of the switching transistor, and can provide circuit protection when hot-plugging occurs at the load input terminal and short-circuit occurs at the load output terminal. The method in the present invention is simple and easy to implement, uses a small number of components, saves costs, improves the utilization efficiency of the device, and at the same time better accommodates the two protection requirements of hot-plug protection and short-circuit protection.

[0045] The beneficial effects of the present invention also include:

[0046] 1) When the voltage at the load output terminal is greater than the voltage at the load input terminal, the circuit will not generate a voltage drop in the load access unit. Therefore, the switching transistor in the load access unit will not conduct, thus isolating the voltage value between the gate and the drain of the first and second switching transistors and preventing the gate voltage of the first and second switching transistors from drifting. At this time, the gate of the NMOS switching transistor in the circuit is pulled to the ground potential under the pull-down action of the internal logic control module, thus preventing the first and second switching transistors from being accidentally turned on.

[0047] 2) When a hot-plug operation occurs, the switching transistors in the hot-plug protection unit, the short-circuit protection unit, and the load access unit will conduct in sequence. When the voltage at the load input terminal rises rapidly, the energy coupled from the drain to the gate of Mnpwr1 through the inter-electrode capacitance of Mnpwr1 can be discharged through the conducting MOS transistor in the load access unit, thus stabilizing the voltage at the Gate terminal and preventing the first and second switching transistors from conducting.

[0048] The applicant of the present invention has made a detailed description and explanation of the embodiments of the present invention in combination with the accompanying drawings of the specification. However, those skilled in the art should understand that the above embodiments are only the preferred implementation schemes of the present invention, and the detailed description is only to help readers better understand the spirit of the present invention, rather than a limitation on the protection scope of the present invention. On the contrary, any improvement or modification made based on the spirit of the present invention should fall within the protection scope of the present invention.

Claims

1. A short-circuit protection and hot-swap protection circuit, characterized in that The circuit includes: a hot-swap protection unit, a short-circuit protection unit, a load access unit, and first and second switching transistors; wherein, The hot-swap protection unit is connected to the input terminal voltage at one end and connected to the short-circuit protection unit at the other end, and is configured to provide a hot-swap protection current to the short-circuit protection unit based on the change of the input terminal voltage during hot-swap; the hot-swap protection unit includes a third switching transistor ; the short-circuit protection unit includes a fourth switching transistor ; the load access unit includes a fifth switching transistor and a sixth switching transistor ; one end of the short-circuit protection unit is connected to the output terminal voltage, one end is connected to the hot-swap protection unit, and the other end is connected to the load access unit, and is configured to generate a voltage drop of the load access unit based on the hot-swap protection current during hot-swap, or to generate a voltage drop of the load access unit based on the change of the output terminal voltage during short-circuit; When a hot plugging operation occurs in the circuit, the voltage at the input terminal increases, and the third switching transistor and the fourth switching transistor are turned on in sequence, and a hot plugging protection current and a voltage drop of the load access unit are generated in sequence; the voltage drop of the load access unit causes the fifth switching transistor and the sixth switching transistor to be turned on simultaneously to prevent the first and second switching transistors from being turned on due to the hot plugging operation; the load access unit is respectively connected to the output terminal voltage, the short-circuit protection unit, and the gates of the first and second switching transistors, and is configured to provide hot-swap protection or short-circuit protection for the first and second switching transistors based on the voltage drop of the load access unit generated thereby.

2. The short-circuit protection and hot-swap protection circuit according to claim 1, wherein: The hot-swap protection unit further includes a first resistor , a first capacitor , and a first Zener diode ; wherein The first resistor and the source electrode of the third switching transistor are respectively connected to the input terminal voltage; The first resistor and the other end of the third switching transistor are grounded through a first capacitor respectively; The first Zener diode is connected to the gate-source of the switching transistor . The drain of the third switching transistor is connected to the short-circuit protection unit.

3. The short-circuit protection and hot-swap protection circuit according to claim 1, wherein: The short-circuit protection unit further includes a second resistor , a second capacitor , a third capacitor , a second Zener diode , a third resistor ; wherein, The second resistor at one end, the gate of the fourth switching transistor and one end of the third capacitor are connected to the hot-swap protection unit and are connected to the input terminal voltage through the second capacitor ; The second resistor The other end of, the fourth switching transistor The source electrode of is connected to the output terminal voltage; The third capacitor has the other end grounded; The second Zener diode is connected to the gate-source of the fourth switching transistor; The third resistor has one end connected to the drain of the fourth switching transistor and the other end connected to the load access unit.

4. The short-circuit protection and hot-swap protection circuit according to claim 1, wherein: The load access unit further includes a load resistor , a third Zener diode , a first parasitic diode , a second parasitic diode ; wherein The fifth switching transistor and the sixth switching transistor have their sources and gates connected to each other and are connected to the short-circuit protection unit; The load resistor is connected to the source and gate of the fifth switching transistor and the sixth switching transistor respectively at both ends; The third Zener diode is respectively connected to the gate-source electrodes of the fifth switching transistor and the sixth switching transistor; The first parasitic diode and the second parasitic diode are respectively connected to the source-drain electrodes of the fifth switching transistor and the sixth switching transistor ; The fifth switching transistor has its drain connected to the output terminal in a current manner, and the sixth switching transistor has its drain connected to the terminal.

5. The short-circuit protection and hot-swap protection circuit according to claim 1, wherein: The gates of the first and second switching transistors are respectively connected to terminal, the sources are connected to each other, and the drains are respectively connected to the input terminal voltage and the output terminal voltage.

6. The short-circuit protection and hot-swap protection circuit according to claim 3, wherein: When a short - circuit action occurs in the circuit, the voltage at the output terminal decreases, and the fourth switching transistor conducts and generates a voltage drop in the load access unit.

7. The short-circuit protection and hot-swap protection circuit according to claim 4, wherein: When a short - circuit action occurs in the circuit, the voltage drop of the load access unit causes the fifth switching transistor and the sixth switching transistor to conduct simultaneously, so as to prevent the first and second switching transistors from being broken down due to the short - circuit action and limit the short - circuit current of the first and second switching transistors.

8. A short-circuit protection and hot-plugging protection method, characterized in that, A short-circuit protection and hot-swap protection circuit as described in any one of claims 1-7 is adopted.

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