Hot plug protection method and power supply device

Abstract

The invention relates to a hot plug protection method and a power supply device, and the method comprises the steps: when a detection terminal detects that the connection state of the power supply device and a to-be-charged device is disconnected, a switch assembly is cut off in the first time, and the switch assembly is connected in series between a voltage converter of the power supply device and a connection port; and maintaining the output voltage of the voltage converter at a first level within a second time, the first time being shorter than the second time. According to the invention, by controlling the voltage difference between the power supply device and the to-be-charged device, the impact current on the connection port during hot plugging is suppressed to be below a safety value, the sparking phenomenon is avoided or obviously reduced, and the service life of the connection port is prolonged.

Description

Technical Field

[0001] The present application relates to the technical field of electronic circuits, and in particular to a hot-swap protection method and a power supply device. Background Art

[0002] Hot plugging, that is, plugging and unplugging while powered on, can easily cause interface damage or equipment failure because the output voltage cannot be quickly reduced to a safe voltage range.

[0003] As consumer electronic products have more and more functions, the power required is also getting higher and higher. Some high-power consumer electronic products require 20V or even 48V power supply. When charging, if the user uses hot plugging, that is, connecting the consumer electronic product when the power supply is energized, it will cause an excessive voltage difference between the two contact points of the connector, resulting in sparks, which will cause oxidation or aging of the contact points of the connector, thus affecting the service life of the connector. Summary of the invention

[0004] Based on this, it is necessary to provide a hot-plug protection method and a power supply device to address the problems in the above-mentioned background technology, so as to solve the hot-plug phenomenon of high-power consumer electronic products in the prior art, which is prone to sparks at the connection, thereby causing oxidation or aging of the contact points of the connector, thereby affecting the service life of the connector.

[0005] In a first aspect, the present application provides a hot-swap protection method. The method is applied to a power supply device, the power supply device includes a connection port, the power supply device provides charging power to a device to be charged through the connection port, the connection port includes a detection terminal, and the connection status between the power supply device and the device to be charged is detected. The method includes:

[0006] When the detection terminal detects that the connection state between the power supply device and the device to be charged is disconnected, the switch component is cut off within the first time; wherein the switch component is connected in series between the voltage converter of the power supply device and the connection port;

[0007] and maintaining the output voltage of the voltage converter at a first level for a second time;

[0008] The first time is shorter than the second time.

[0009] In one of the embodiments, the first time is determined according to the delay time between the disconnection of the connection state and the disconnection of the input terminal of the device to be charged, and the setting range of the first time is between zero and the delay time.

[0010] In one embodiment, the first time is less than 20 ms, and the second time is set between the first time and 275 ms.

[0011] In one embodiment, the voltage difference between the first level and the reference level ranges from -50% to +20%; wherein the reference level is the output voltage of the voltage converter when the power supply device provides charging power to the device to be charged.

[0012] In one embodiment, the method further comprises:

[0013] When it is detected through the detection terminal that the connection state between the power supply device and the device to be charged is disconnected, after the second time and within a third time, the output voltage of the voltage converter is reduced from the first level to the second level; wherein the second level is the output voltage of the voltage converter when the power supply device is in a no-load state.

[0014] In one embodiment, the third time is set between the second time and 275 ms.

[0015] In one embodiment, the method of detecting that the connection state between the power supply device and the device to be charged is disconnected through the detection terminal includes:

[0016] The voltage value on the detection terminal is detected. When the voltage value on the detection terminal is greater than or equal to a first preset voltage, it is considered that the connection between the device to be charged and the power supply device is disconnected.

[0017] In one embodiment, the method further comprises:

[0018] When the detection terminal detects that the connection state between the power supply device and the device to be charged is connected, and the first preset condition is met, the switch component is turned on to communicate with the device to be charged.

[0019] In one of the embodiments, during the second time, the voltage difference between the power supply device and the device to be charged is no more than 5V.

[0020] In one embodiment, the method of detecting that the connection state between the power supply device and the device to be charged is connected through the detection terminal includes:

[0021] The voltage value on the detection terminal is detected. If the voltage value on the detection terminal is less than or equal to a second preset voltage, it is considered that the device to be charged is connected to the power supply device.

[0022] In one embodiment, the method for determining the first preset condition includes:

[0023] The voltage value of the power terminal of the connection port and the output voltage of the voltage converter are detected. When the voltage value of the power terminal is less than or equal to a third preset voltage and the output voltage of the voltage converter is equal to a second level, it is considered that the first preset condition is met.

[0024] In a second aspect, the present application further provides a power supply device. The power supply device comprises:

[0025] Connection ports;

[0026] A processor, configured to perform hot-swap protection on the power supply device by using the hot-swap protection method described in any one of the first aspects;

[0027] A voltage converter, used to output a corresponding voltage according to the instruction output by the processor;

[0028] The switch component is connected in series between the voltage converter and the connection port, and is used to connect or disconnect the power supply circuit of the power supply device according to the control signal of the processor.

[0029] In one embodiment, the switch component includes a MOSFET having an integral diode for maintaining a current path between the connection port and the voltage converter after the switch component is disconnected.

[0030] In one embodiment, the switch component includes two semiconductor switches with a common source and a common gate.

[0031] In one embodiment, the semiconductor switch is a gallium nitride switch or a silicon carbide switch.

[0032] In one embodiment, the connection port includes a plurality of pins, wherein the length of the pin corresponding to the detection terminal is smaller than the length of the remaining pins, and the smaller length range is between 0.3-0.5 mm.

[0033] The above hot-swap protection method and power supply device have at least the following advantages:

[0034] By controlling the voltage difference between the power supply device and the device to be charged, the impact current on the connection port during hot plugging is suppressed to below the safe value, avoiding or significantly reducing the sparking phenomenon and increasing the service life of the connection port. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The drawings constituting a part of this application are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0036] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0037] Figure 1 A structural block diagram of an application environment of a hot-swap protection method in an embodiment;

[0038] Figure 2 is a structural block diagram of a power supply device in one embodiment;

[0039] Figure 3 A schematic diagram of the connection between a power supply device and a device to be charged in one embodiment;

[0040] Figure 4 is a schematic diagram of current waveforms under different voltage differences in one embodiment;

[0041] Figure 5 is a schematic diagram of current waveforms under different voltage differences in another embodiment;

[0042] Figure 6 is a schematic diagram of current waveforms under different voltage differences in another embodiment;

[0043] Figure 7 is a connection diagram of a power supply device in one embodiment;

[0044] Figure 8 is a connection diagram of a power supply device in another embodiment;

[0045] Fig. 9 A schematic diagram of a voltage waveform after the detection terminal is shortened in one embodiment;

[0046] Fig.10 A schematic diagram of a hot-swap protection method according to an embodiment of the present invention;

[0047] Fig.11 A timing diagram of a hot-swap protection method in an embodiment;

[0048] Fig.12 A schematic diagram of a voltage waveform of a switch component after disconnection in one embodiment;

[0049] Fig.13 A schematic diagram of a voltage waveform of a voltage Vadp at the instant of disconnection in one embodiment;

[0050] Fig.14 A waveform diagram of the voltage V0 being maintained at the first level after disconnection in one embodiment;

[0051] Fig.15 FIG. 4 is a waveform diagram of the voltage V0 decreasing to a second level after disconnection in one embodiment. DETAILED DESCRIPTION

[0052] In order to facilitate the understanding of the present application, the present application will be described more fully below with reference to the relevant drawings. The preferred embodiments of the present application are provided in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present application more thorough and comprehensive.

[0053] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0054] In the case of using “including”, “having”, and “comprising” described herein, another component may be added unless a clear limiting term such as “only”, “consisting of”, etc. is used. Unless mentioned otherwise, a term in the singular form may include a plural form and should not be understood as being one in number.

[0055] It should be understood that although the terms "first", "second", etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. For example, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element without departing from the scope of the present application.

[0056] In this application, unless otherwise clearly specified and limited, the terms "connected", "connection" and the like should be understood in a broad sense, for example, it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0057] The hot plug protection method provided in the embodiment of the present application can be applied to Figure 1In the application environment shown. Among them, the power supply device includes at least one connection port, and the power supply device can provide charging power to the device to be charged through the connection port, and the connection port of the device to be charged matches the connection port of the power supply device. It should be understood that when the power supply device provides charging power to the device to be charged, it should follow the charging protocol between the two. The charging protocol is a standard protocol. For example, when the connection port is a Type-c interface, the PD (USB Power Delivery) charging protocol is followed for charging. The PD charging protocol is one of the current mainstream fast charging protocols. It is a power transmission protocol published by the USB-IF organization. It can increase the current default maximum power of the Type-c interface of 5V / 2A to 240W.

[0058] Furthermore, the connection port includes a detection terminal for detecting the connection status between the power supply device and the device to be charged. It should be understood that the connection port also includes a power terminal for providing a charging voltage to the device to be charged; and a communication terminal for realizing signal transmission between the power supply device and the device to be charged.

[0059] The devices to be charged may be, but are not limited to, various personal computers, laptops, smart phones, tablet computers, IoT devices and portable wearable devices. IoT devices may be smart speakers, smart TVs, smart air conditioners, smart car-mounted devices, etc. Portable wearable devices may be smart watches, smart bracelets, head-mounted devices, etc.

[0060] See also Figure 2 In some embodiments, the present application provides a power supply device, which specifically includes: a processor, a voltage converter, a switch component and a connection port.

[0061] The processor includes a plurality of output terminals, each of which is respectively connected to a control terminal of a voltage converter, a control terminal of a switch component, and a communication terminal of a connection port, and is used to perform hot-swap protection on a power supply device according to a preset setting. Specifically, the processor outputs different control signals to the voltage converter and the switch component, so that the voltage converter outputs a corresponding voltage according to the setting according to the control signal, and the switch component is turned on or off according to the control signal; the processor also transmits signals with the device to be charged through the communication terminal when a device to be charged is connected to the connection port.

[0062] See also Figure 3 , the voltage converter, the switch component and the connection port are connected in sequence. When the connection port of the power supply device and the connection port of the device to be charged are connected, the power supply device can provide charging power to the device to be charged through the connection port. At this time, the voltage on the power supply device side is Vadp and the voltage on the device to be charged side is Vbus.

[0063] When Vadp > Vbus, the current flowing from the power supply device end to the device to be charged end may cause a sparking phenomenon. Specifically, when the capacitor C3 is in a small heavy load condition, after the connection terminal is pulled out, the power supply device end discharges slowly and the device to be charged end discharges quickly. When the connection terminal is plugged back in, there is a high probability of sparking from the power supply device end to the device to be charged end.

[0064] When Vadp < Vbus, the current flowing from the device to be charged end to the power supply device end may cause a sparking phenomenon. Specifically, when the capacitor C3 is in a large light load condition, after the connection terminal is pulled out, the power supply device end discharges quickly and the device to be charged end discharges slowly. When the connection terminal is plugged back in, there is a low probability of sparking from the device to be charged end to the power supply device end.

[0065] Please refer to Figure 4-Figure 6 , Figure 4-Figure 6 which shows the values of the current Iinrush at the power supply device end and the device to be charged end under different voltage differences between Vadp and Vbus, and the capacitance value of the capacitor C3 is 10uF. Figure 4 simulates the situation where Vadp slowly discharges to 20V and Vbus quickly discharges to 9V after the device to be charged end is pulled out. When the two ends are plugged together, the current Iinrush is 28.3A, and at this time, the sparking phenomenon can be reproduced. Figure 5 simulates the situation where Vadp slowly discharges to 20V and Vbus quickly discharges to 15V after the device to be charged end is pulled out. When the two ends are plugged together, the current Iinrush is 13.3A. Compared with Figure 4 the value of the current Iinrush is significantly reduced, and there is no obvious sparking phenomenon at this time. Figure 6 simulates the situation where Vadp slowly discharges to 20V and Vbus quickly discharges to 20V after the device to be charged end is pulled out. When the two ends are plugged together, the current Iinrush is about 0A, and there is no obvious sparking phenomenon at this time. It can be seen that the lower the voltage difference between the power supply device end and the device to be charged end, the smaller the value of the current Iinrush, and the lower the probability of the sparking phenomenon. Based on this, the present application controls the voltage difference between the power supply device end and the device to be charged end to reduce the sparking probability when the device to be charged is connected to the power supply device.

[0066] Specifically, the processor can detect the connection status between the power supply device and the device to be charged through the detection terminal. When it is detected that the connection status between the power supply device and the device to be charged is connected, the processor outputs a control signal to the control end of the switch component to put the switch component in an on state. At this time, the output voltage of the voltage converter is output to the input end of the device to be charged through the switch component and the connection port to provide a power supply voltage for the device to be charged; when the processor detects that the connection status between the power supply device and the device to be charged is disconnected, the processor outputs a control signal to the control end of the switch component within a first time to put the switch component in a disconnected state. Furthermore, the processor also maintains the output voltage of the voltage converter at a first level within a second time to avoid the voltage difference between the device to be charged and the power supply device being greater than 5V when the device to be charged is connected to the connection port, and a spark is prevented from occurring between the device to be charged and the power supply device. Among them, the first time is less than the second time.

[0067] See also Figure 7 , illustratively, the switch component in this embodiment includes a MOSFET, that is, Figure 7 The switch tube Q1 shown, wherein the MOSFET includes an integrated diode, the cathode of the body diode is connected to the positive electrode of the output end of the voltage converter, and the anode of the body diode is connected to the positive electrode of the power supply terminal of the connection port, for maintaining the current path between the connection port and the voltage converter after the MOSFET is disconnected. It should be understood that the above transistor structure is only an example, and other controllable switch tubes and diodes can also be used in actual applications to achieve the above functions.

[0068] See also Figure 8 In some embodiments, the switch assembly further comprises two semiconductor switches connected in series with a common source, and the semiconductor switches are gallium nitride switches or silicon carbide switches. When two semiconductor switches are used, the reversely connected semiconductor switches can prevent energy backflow.

[0069] Please continue reading Figure 7, further, a capacitor C1 is provided between the output end of the voltage converter and the ground wire of the power supply device, which is used to filter the output voltage V0 of the voltage converter. A capacitor C2 is provided between the power terminal of the connection port and the ground wire. When a device to be charged is connected to the power supply device, the switch component is turned on. At this time, the voltage Vadp across the capacitor C2 is equal to the output voltage V0 of the voltage converter, and a charging voltage can be provided for the connected device to be charged. When the processor detects that the access state of the device to be charged is disconnected, a control signal is sent to the control end of the switch tube Q1 within the first time to disconnect the switch tube Q1. At this time, the voltage Vadp is discharged through the capacitor C2. By reasonably setting the capacitance of the capacitor C2, such as 0.1uF, the voltage Vadp can be rapidly reduced. At the same time, the processor maintains the output voltage V0 of the voltage converter at the first level in the second time. At this time, the diode is in a reverse biased state, avoiding or significantly reducing the sparking phenomenon from the end of the device to be charged to the end of the power supply device.

[0070] Optionally, in order to reduce the sparking phenomenon during hot plugging, the embodiment of the present application also improves the connection port of the power supply device. Specifically, the connection port includes multiple pins, including a detection terminal, a power terminal, and a communication terminal, wherein the length of the pin corresponding to the detection terminal is less than the length of the remaining pins, and the length range of the less than is between 0.3 and 0.5 mm. With this design, when the power supply device is disconnected from the device to be charged, the controller can detect the disconnection state more quickly, thereby turning off the switch component more quickly.

[0071] See also Fig. 9 , Fig. 9 : is a schematic diagram of the voltage waveform after the detection terminal is shortened, wherein Vnormal_pin is the voltage value on the normal length pin of the connection port of the power supply device, Vccpin is the voltage value after the detection terminal is shortened, and Vadp is the voltage across the capacitor C2. Fig. 9 It can be seen from the waveform in that when the detection terminal is disconnected, the difference in change time between the voltage Vccpin and the voltage Vnormal_pin is 11.6ms, and during this time, the voltage Vadp has discharged to 0V. It can be seen that after shortening the pin corresponding to the detection terminal to an appropriate length, the controller can detect the disconnection state more quickly, thereby turning off the switch component more quickly.

[0072] The above power supply device detects the connection status between the power supply device and the device to be charged through the detection terminal. When the connection status is detected to be disconnected, the switch component is cut off in the first time to avoid sparking from the power supply device end to the device to be charged end; and the output voltage of the voltage converter is maintained at the first level in the second time to avoid sparking from the device to be charged end to the power supply device end due to excessive voltage difference when the device to be charged is connected to the connection port. The above scheme can suppress the impact current on the connection port during hot plugging to below the safe value, avoid or significantly reduce the sparking phenomenon, and increase the service life of the connection port.

[0073] See also Fig.10 In some embodiments, the present application provides a hot-swap protection method, which is applied to a power supply device, the power supply device includes a connection port, and the power supply device can provide charging power to the device to be charged through the connection port. Furthermore, the connection port includes a detection terminal, which is used to detect the connection status between the power supply device and the device to be charged. Specifically, the following steps are included:

[0074] Step S1002, when it is detected through the detection terminal that the connection state between the power supply device and the device to be charged is disconnected, the switch component is cut off within the first time; wherein the switch component is connected in series between the voltage converter and the connection port of the power supply device.

[0075] Step S1004: maintaining the output voltage of the voltage converter at the first level within a second time; wherein the first time is shorter than the second time.

[0076] Specifically, the charging protocol specifies the timing of the power supply device and the device to be charged. Taking the PD charging protocol as an example, the PD charging protocol specifies the timing of multiple action stages, and the specific time of each timing is determined by the device manufacturer based on the specific hardware and system requirements. Exemplarily, in this embodiment, tPDDebounce is the delay time for the device to be charged to cut off the output voltage after the detection terminal is disconnected, and its allowable range is 10 to 20ms; tSRCDisconnect is the time for the power supply device to cut off the switch component after the detection terminal is disconnected, and its allowable range is 0 to 20ms. In addition, according to the requirements of the PD charging protocol, when the device to be charged is not connected to the power supply device, that is, when the power supply device is in an unloaded state, the output voltage of the voltage converter must be maintained at about 5V, and it is stipulated that the time from the power supply device detecting the disconnection of the detection terminal to adjusting the output voltage of the voltage converter to 5V is 275ms.

[0077] According to the timing in the above-mentioned PD charging protocol, when the power supply device detects through the detection terminal that the connection state between the power supply device and the device to be charged is disconnected, the embodiment of the present application cuts off the switch component within the first time to avoid excessive voltage difference between the power supply device and the device to be charged, resulting in sparking from the power supply device end to the device to be charged. Optionally, the first time is determined based on the delay time between the disconnection of the connection state and the disconnection of the input end of the device to be charged, that is, the tPDDebounce time mentioned above. In this embodiment, the setting range of the first time is between zero and the delay time. Exemplarily, the first time is less than 20ms.

[0078] The second time is the time that the processor maintains the output voltage of the voltage converter at the first level. The second time and the first level are set to maintain the reverse bias state of the body diode of the switch component to avoid energy recharge. Exemplarily, the second time is set between the first time and 275ms. Exemplarily, the voltage difference between the first level and the reference level ranges from -50% to +20%; wherein the reference level is the output voltage of the voltage converter when the power supply device provides charging power to the device to be charged.

[0079] Optionally, the hot-swap protection method of the embodiment of the present application further includes:

[0080] When the detection terminal detects that the connection state between the power supply device and the device to be charged is disconnected, after the second time and within the third time, the output voltage of the voltage converter is reduced from the first level to the second level; wherein the second level is the output voltage of the voltage converter when the power supply device is in a no-load state. Exemplarily, the third time is set between the second time and 275ms.

[0081] In the above embodiment, when it is detected that the connection state between the power supply device and the device to be charged is disconnected, the switch component is cut off within the first time to avoid sparking from the power supply device end to the device to be charged; and the output voltage of the voltage converter is maintained at the first level within the second time to avoid sparking from the device to be charged end to the power supply device end due to excessive voltage difference; finally, within the third time, the first level is reduced to the second level to wait for the insertion signal of the device to be charged, and the timing satisfies 0≤first time≤second time<third time≤275ms.

[0082] Optionally, the method for detecting that the connection state between the power supply device and the device to be charged is disconnected through the detection terminal includes:

[0083] The voltage value on the detection terminal is detected. When the voltage value on the detection terminal is greater than or equal to a first preset voltage, it is considered that the connection between the device to be charged and the power supply device is disconnected.

[0084] Specifically, the power supply device includes an input terminal and an output terminal. The input terminal is connected to an AC power source and is used to convert the connected AC power into a DC power of a corresponding voltage value for use by the inserted device to be charged. When the input terminal of the power supply device is powered on, and the output terminal is in a connected state and a disconnected state with the load, the voltage on the detection terminal will change. By detecting the voltage change, the connection status of the power supply device and the device to be charged can be confirmed. Exemplarily, the first preset voltage in this embodiment is 2.8V. If the voltage value on the detection terminal is greater than or equal to 2.8V, it is considered that the device to be charged and the power supply device are in a disconnected state.

[0085] Optionally, the hot-swap protection method of the embodiment of the present application further includes:

[0086] When the detection terminal detects that the connection state between the power supply device and the device to be charged is connected, and the first preset condition is met, the switch component is turned on to communicate with the device to be charged.

[0087] Optionally, the method of detecting that the connection state between the power supply device and the device to be charged is connected through the detection terminal includes:

[0088] The voltage value on the detection terminal is detected. If the voltage value on the detection terminal is less than or equal to the second preset voltage, it is considered that the device to be charged is connected to the power supply device. For example, the second preset voltage in this embodiment is 1.7V. If the voltage value on the detection terminal is less than or equal to 1.7V, it is considered that the device to be charged is in a connected state with the power supply device.

[0089] Optionally, the first preset condition is determined by:

[0090] The voltage value of the power terminal of the connection port and the output voltage of the voltage converter are detected. When the voltage value of the power terminal is less than or equal to the third preset voltage and the output voltage of the voltage converter is equal to the second level, it is considered that the first preset condition is met.

[0091] Specifically, at the moment when the device to be charged is inserted into the connection port, the voltage value on the power terminal of the connection port is close to zero, and the output voltage of the voltage converter is maintained at the second level. At this time, the power supply device is in a normal working state and can communicate normally with the connected device to be charged and provide charging power. Exemplarily, the third preset voltage in this embodiment is 0.8V and the second level is 5V. It should be understood that the values ​​of the first preset voltage, the second preset voltage and the third preset voltage can be adjusted appropriately as needed. For example, the value range of the second level is set between 4.5 and 5.5V, and the output voltage of the voltage converter to be detected is greater than or equal to 4.5V and less than or equal to 5.5V, which is considered to meet the requirements.

[0092] Furthermore, after the power supply device is powered on, the processor will continue to detect the voltage value on the detection terminal to determine the connection status between the power supply device and the device to be charged. If the connection status is disconnected, the method steps in the above embodiment will be immediately executed to avoid sparking caused by excessive voltage difference between the power supply device and the device to be charged. If the connection status is connected, the voltage value of the power terminal of the connection port and the voltage value of the output terminal of the voltage converter will continue to be detected. If the above voltage values ​​meet the first preset condition, the switch component will be turned on to communicate with the connected device to be charged and provide it with a suitable charging voltage.

[0093] In order to enable those skilled in the art to fully understand the present application, the working principle of the hot-swap protection method of the present application is described in detail below:

[0094] See also Figure 7 and Fig.11 , Fig.11 The figure shows a timing diagram of the hot-swap protection method in this embodiment, wherein Vccpin is the voltage value on the detection terminal, Vadp is the voltage value across the capacitor C2, Vbus is the voltage value at the connection of the device to be charged, and V0 is the output voltage of the voltage converter.

[0095] When the power supply device charges the device to be charged, the voltage value of the voltage Vccpin is less than or equal to the second preset voltage, the voltage Vadp, the voltage Vbus and the voltage V0 are all high level, and the specific voltage value depends on the model of the device to be charged.

[0096] When the processor detects that the voltage value of the detection terminal is reversed, and the voltage after the reverse is greater than or equal to the first preset voltage, it is considered that the power supply device and the device to be charged are disconnected, and the voltage Vbus starts to discharge from the moment of the reverse; if the switch tube Q1 is cut off within the first time (T1 shown in the figure), the voltage Vadp starts to discharge after the switch tube Q1 is disconnected; in order to prevent the voltage Vbus from being greater than the voltage Vadp, causing energy to flow back from the device to be charged to the power supply device, the voltage V0 is maintained at the first level within the second time (T2 shown in the figure) to make the body diode of the switch tube Q1 in a reverse biased state. After the discharge of the voltage Vbus is completed, the voltage V0 is reduced to the second level within the third time (T3 shown in the figure) to wait for the insertion signal of the device to be charged.

[0097] See also Fig.12 , Fig.12 This is a schematic diagram of the voltage waveform of the switch component after disconnection. Fig.12As can be seen from the waveform in, when the detection terminal is disconnected, the voltage Vccpin on it changes immediately and rises to a high level; within the first time after the detection terminal is disconnected, the voltage Vadp and the voltage V0 are at the same potential. For example, the charging voltage required by the device to be charged is 20V. When the switch Q1 is turned off immediately after the detection terminal is disconnected, the voltage Vadp starts to discharge from 20V to 0V. At this time, the first time is about 3ms, which meets the requirements of the PD charging protocol. It should be noted that Fig.12 It is an enlarged view of the voltage waveform. When the charging voltage is 20V, the voltage difference between the voltage Vadp and the voltage V0 is about 0.1V, which can be regarded as the same potential.

[0098] See also Fig.13 , Fig.13 This is a voltage waveform diagram of the instantaneous voltage Vadp after disconnection. Fig.13 It can be seen from the waveform in that when the detection terminal is disconnected, the time for the voltage Vadp to drop from 20V to 0V is about 1ms, and the capacitance of capacitor C2 is small, only 0.1uF, and no spark will occur from the power supply end to the device to be charged.

[0099] See also Fig.14 , Fig.14 The waveform diagram of the voltage V0 maintained at the first level after disconnection is shown. Fig.14 As can be seen from the waveform in, when the detection terminal is disconnected, the voltage Vccpin changes immediately and rises to a high level; the voltage Vadp and the voltage Vbus begin to discharge, and the voltage V0 is maintained within the error range of the 20V voltage level in the second time, ensuring that the cathode voltage of the body diode is greater than the anode voltage and is in a reverse bias state to prevent sparks from the end of the device to be charged to the end of the power supply device. At this time, the second time is about 35ms, which meets the requirements of the PD charging protocol.

[0100] See also Fig.15 , Fig.15 The waveform diagram of the voltage V0 decreasing from the first level to the second level after the connection is disconnected is shown. Fig.15 It can be seen from the waveform that when the detection terminal is disconnected, the voltage V0 is maintained at 20V in the second time. After the third time, the voltage V0 drops from 20V to 5V. At this time, the third time is 221ms, which satisfies tPDDebounce<second time<third time<275ms, which meets the requirements of the PD charging protocol.

[0101] The above hot-swap protection method detects the connection status between the power supply device and the device to be charged by detecting the terminal. When the connection status is detected to be disconnected, the switch component is cut off in the first time to avoid sparking from the power supply device end to the device to be charged end; and the output voltage of the voltage converter is maintained at the first level in the second time to avoid sparking from the device to be charged end to the power supply device end due to excessive voltage difference when the device to be charged is connected to the connection port. The above scheme can suppress the impact current on the connection port during hot plugging to below the safe value, avoid or reduce the sparking phenomenon, and increase the service life of the connection port.

[0102] Please note that the above embodiments are for illustrative purposes only and are not meant to limit the present invention.

[0103] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0104] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0105] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. A hot-swap protection method, characterized in that: Applied to a power supply device, the power supply device includes a connection port, the power supply device provides charging power to a device to be charged through the connection port, the connection port includes a detection terminal, and the connection status between the power supply device and the device to be charged is detected. The method includes: When the detection terminal detects that the connection state between the power supply device and the device to be charged is disconnected, the switch component is cut off within the first time, wherein the switch component is connected in series between the voltage converter of the power supply device and the connection port; and maintaining the output voltage of the voltage converter at a first level for a second time; The first time is shorter than the second time.

2. The method according to claim 1, characterized in that: The first time is determined according to the delay time between the disconnection of the connection state and the disconnection of the input terminal of the device to be charged, and the setting range of the first time is between zero and the delay time.

3. The method according to claim 2, characterized in that: The first time is less than 20 ms, and the second time is set between the first time and 275 ms.

4. The method according to claim 1, characterized in that: The voltage difference between the first level and the reference level ranges from -50% to +20%; wherein the reference level is the output voltage of the voltage converter when the power supply device provides charging power to the device to be charged.

5. The method according to claim 1, characterized in that The method further comprises: When it is detected through the detection terminal that the connection state between the power supply device and the device to be charged is disconnected, after the second time and within a third time, the output voltage of the voltage converter is reduced from the first level to the second level; wherein the second level is the output voltage of the voltage converter when the power supply device is in a no-load state.

6. The method according to claim 5, characterized in that The third time is set between the second time and 275ms.

7. The method according to any one of claims 1 to 6, characterized in that The method of detecting that the connection state between the power supply device and the device to be charged is disconnected through the detection terminal comprises: The voltage value on the detection terminal is detected, and when the voltage value on the detection terminal is greater than or equal to a first preset voltage, it is considered that the connection between the device to be charged and the power supply device is disconnected.

8. The method according to any one of claims 1 to 6, characterized in that The method further comprises: When the detection terminal detects that the connection state between the power supply device and the device to be charged is connected and meets a first preset condition, the switch component is turned on to communicate with the device to be charged.

9. The method according to any one of claims 1 to 6, characterized in that: During the second time, the voltage difference between the power supply device and the device to be charged is no more than 5V.

10. The method according to claim 8, characterized in that The method of detecting that the connection state between the power supply device and the device to be charged is connected through the detection terminal comprises: The voltage value on the detection terminal is detected. If the voltage value on the detection terminal is less than or equal to a second preset voltage, it is considered that the device to be charged is connected to the power supply device.

11. The method according to claim 8, characterized in that The method for determining the first preset condition includes: The voltage value of the power terminal of the connection port and the output voltage of the voltage converter are detected. When the voltage value of the power terminal is less than or equal to a third preset voltage and the output voltage of the voltage converter is equal to a second level, it is considered that the first preset condition is met.

12. A power supply device, characterized in that: include: Connection ports; A processor, configured to perform hot-swap protection on the power supply device by using the hot-swap protection method described in any one of claims 1 to 10; A voltage converter, used to output a corresponding voltage according to the instruction output by the processor; The switch component is connected in series between the voltage converter and the connection port, and is used to connect or disconnect the power supply circuit of the power supply device according to the control signal of the processor.

13. The power supply device according to claim 12, characterized in that: The switch component includes a MOSFET having an integral diode for maintaining a current path from the connection port to the voltage converter after the switch component is disconnected.

14. The power supply device according to claim 12, characterized in that: The switch component includes two semiconductor switches with a common source and a common gate.

15. The power supply device according to claim 14, characterized in that: The semiconductor switch is a gallium nitride switch or a silicon carbide switch.

16. The power supply device according to claim 12, characterized in that: The connection port includes a plurality of pins, wherein the length of the pin corresponding to the detection terminal is smaller than the length of the other pins, and the smaller length range is between 0.3 and 0.5 mm.

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