A fast charging protection method

Abstract

The present application provides a fast charging protection method, including: during the fast charging process, the fast charging protection circuit detects the fast charging protocol signal in real time; when the fast charging protocol signal disappears, the fast charging protection circuit outputs an unplugging signal, wherein the fast charging protocol signal disappears when the external device is unplugged; and the voltage conversion module of the fast charging protection circuit is controlled according to the unplugging signal to reduce the output voltage from the fast charging voltage to a preset voltage; wherein, the time required from the detection of the disappearance of the fast charging protocol signal to the start of the voltage conversion module to reduce the output voltage is less than the time required for the external device to be completely unplugged from the beginning. In this way, the unplugging action of the external device can be detected in advance, and the output voltage can be reduced before the external device is completely unplugged, thereby effectively reducing the overshoot amplitude of the output voltage.

Description

Technical Field

[0001] The present application relates to the field of charging technology, and in particular to a fast charging protection circuit and method, a fast charging chip, and a fast charging power supply device having the fast charging protection circuit or the fast charging chip. Background Art

[0002] In recent years, with the development of fast charging technology, various fast charging technologies have been applied more and more widely. Mobile terminals, such as mobile phones and tablets, will apply for fast charging voltage from fast charging power supply devices with fast charging chips, such as fast charging mobile power supplies or fast charging adapters, through fast charging protocols to shorten the charging time of mobile terminals. Taking a fast charging mobile power supply with a fast charging chip as an example, the current fast charging mobile power supply can output voltages of different voltage levels such as 9V, 12V, and 15V according to the fast charging protocol. For example, QC protocol 2.0 can apply for 9V or 12V voltage, and PD protocol can apply for 9V, 12V, or 15V voltage. When using a fast charging mobile power supply to charge a mobile terminal, if the mobile terminal is suddenly unplugged during the fast charging process, the output voltage will overshoot due to the transient response characteristics of the power supply of the fast charging mobile power supply. If the overshoot voltage amplitude is too large, it will have a certain impact on the safety of the fast charging mobile power supply, and even seriously damage the fast charging mobile power supply. Summary of the invention

[0003] The present application provides a fast charging protection circuit and method, a fast charging chip, and a fast charging power supply device, which can detect the unplugging action of an external device in advance and quickly in case the external device is suddenly unplugged during the fast charging process, and reduce the output voltage in advance before the external device is completely unplugged, thereby effectively reducing the overshoot amplitude of the output voltage and improving the safety of fast charging power supply devices, such as fast charging mobile power supplies or fast charging adapters.

[0004] The first aspect of the present application provides a fast charging protection circuit, which includes a USB interface, a voltage conversion module, a fast charging control module, and a plug-in detection module. The USB interface is used to be electrically connected to an external device. The voltage conversion module is electrically connected to the USB interface. The fast charging control module is electrically connected to the voltage conversion module and the USB interface respectively, and the fast charging control module is used to obtain the fast charging protocol signal of the external device through the USB interface, and identify the fast charging voltage request of the external device according to the fast charging protocol signal, and control the voltage conversion module to output the corresponding fast charging voltage to the USB interface according to the fast charging voltage request, so as to quickly charge the external device. The plug-in detection module is electrically connected to the USB interface, and is used to detect the fast charging protocol signal in real time through the USB interface, and output a pull-out signal when it is detected that the fast charging protocol signal disappears. Wherein, the fast charging protocol signal disappears when the external device begins to be unplugged. The fast charging control module is also electrically connected to the output end of the plug-in detection module, and the fast charging control module is also used to control the voltage conversion module to reduce the output voltage from the fast charging voltage to a preset voltage when receiving the pull-out signal. Among them, the time required from the plug-in detection module detecting the disappearance of the fast charging protocol signal to the voltage conversion module starting to reduce the output voltage is less than the time required for the external device to be completely unplugged from the beginning.

[0005] The second aspect of the present application provides a fast charging chip, which is used in a fast charging power supply device. The fast charging power supply device includes a USB interface electrically connected to an external device. The fast charging chip includes a voltage conversion module, a fast charging control module, and a plug-in detection module. The voltage conversion module is electrically connected to the USB interface. The fast charging control module is electrically connected to the voltage conversion module and the USB interface respectively, and the fast charging control module is used to obtain the fast charging protocol signal of the external device through the USB interface, and identify the fast charging voltage request of the external device according to the fast charging protocol signal, and control the voltage conversion module to output the corresponding fast charging voltage to the USB interface according to the fast charging voltage request, so as to quickly charge the external device. The plug-in detection module is electrically connected to the USB interface, and is used to detect the fast charging protocol signal in real time through the USB interface, and output an unplug signal when it is detected that the fast charging protocol signal disappears. Wherein, the fast charging protocol signal disappears when the external device begins to be unplugged. The fast charge control module is also electrically connected to the output end of the plug-in detection module, and the fast charge control module is also used to control the voltage conversion module to reduce the output voltage from the fast charge voltage to a preset voltage when receiving the unplug signal. The time required from the plug-in detection module detecting the disappearance of the fast charge protocol signal to the voltage conversion module starting to reduce the output voltage is less than the time required for the external device to be completely unplugged from the beginning.

[0006] The third aspect of the present application provides a fast charging protection circuit, which includes a USB interface electrically connected to an external device and the fast charging chip described in the second aspect. The voltage conversion module, fast charging control module and plug detection module of the fast charging chip are all electrically connected to the USB interface.

[0007] The fourth aspect of the present application provides a fast charging power supply device, which includes the fast charging protection circuit and the power input interface described in the first aspect or the third aspect above. Wherein, the fast charging protection circuit is used to charge an external device. The power input interface is electrically connected to the fast charging protection circuit, and the power input interface is used to receive an external power supply to provide an input voltage to the fast charging protection circuit.

[0008] The fifth aspect of the present application provides a fast charging protection method, which is applied to the fast charging protection circuit described in the first or third aspect above, or to the fast charging chip described in the second aspect above, or to the fast charging power supply device described in the fourth aspect above. The fast charging protection method includes: during the fast charging process, real-time detection of the fast charging protocol signal by the plug-in detection module; when the plug-in detection module detects that the fast charging protocol signal disappears, the plug-in detection module outputs an unplug signal, wherein the fast charging protocol signal disappears when the external device begins to be unplugged; and according to the unplug signal, the voltage conversion module is controlled to reduce the output voltage from the fast charging voltage to the preset voltage. The time required from the time when the plug-in detection module detects that the fast charging protocol signal disappears to the time when the voltage conversion module begins to reduce the output voltage is less than the time required for the external device to be completely unplugged from the beginning of being unplugged.

[0009] The fast charging protection circuit and method proposed in the present application detect the fast charging protocol signal in real time through the plug-in detection module during the fast charging process, have a fast response speed, can quickly detect the unplugging action of the external device in advance, and reduce the output voltage of the voltage conversion module in advance before the external device is completely unplugged, thereby effectively reducing the overshoot amplitude of the output voltage, thereby improving the reliability of fast charging power supply equipment, such as a fast charging mobile power supply or a fast charging adapter. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] In order to more clearly illustrate the implementation methods of the present application or the technical solutions in the prior art, the drawings required for use in the implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0011] Figure 1 The figure is a schematic diagram of the structure of a fast charging circuit provided in the prior art.

[0012] Figure 2 for Figure 1 The schematic diagram shows the voltage overshoot of the output voltage of the fast charging circuit when the external device is unplugged.

[0013] Figure 3 A schematic diagram of the functional modules of a fast charging protection circuit provided in the first embodiment of the present application.

[0014] Figure 4 for Figure 3 A circuit structure schematic diagram of a fast charging protection circuit shown.

[0015] Figure 5Figure 2 is a schematic diagram of the pin structure of two USB interfaces, where: Figure 5 The (A) structure is the pin structure of the USB TYPE-A interface; Figure 5 The (B) structure is the pin structure of the USB TYPE-C interface.

[0016] Figure 6 for Figure 3 Another circuit structure schematic diagram of the fast charging protection circuit shown.

[0017] Figure 7 for Figure 3 , Figure 4 or Figure 6 The schematic diagram shows the voltage overshoot of the output voltage of the fast charge protection circuit when the external device is unplugged.

[0018] Figure 8 A schematic diagram of the functional modules of a fast charging protection circuit provided in the second embodiment of the present application.

[0019] Fig. 9 A schematic diagram of the functional modules of a fast charging power supply device provided in an embodiment of the present application.

[0020] Fig.10 A schematic diagram of the functional modules of a fast-charging mobile power supply provided in an embodiment of the present application.

[0021] Fig.11 A schematic diagram of the functional modules of a fast charging adapter provided in an embodiment of the present application.

[0022] Fig.12 A flowchart of a fast charging protection method provided in an embodiment of the present application.

[0023] Main component symbols

[0024] Fast charging circuit 100

[0025] Voltage conversion module 11, 31, 41, 51, 621

[0026] Fast charging control module 12, 32, 42, 52, 622

[0027] USB ports 13, 33, 43, 53, 61

[0028] External device 200

[0029] USB charging cable 21

[0030] Fast charge protection circuit 300, 400, 500, 600, 72, 83, 93

[0031] Plug and unplug detection modules 34, 44, 54, 623

[0032] Comparison module 341

[0033] Comparators 441, 5411, 5412

[0034] Debounce modules 342, 442, 5421, 5422

[0035] Logic Gate Circuit 543

[0036] Fast charging chip 62

[0037] Fast charging power supply equipment 700

[0038] Power input interface 71, 81, 91

[0039] Fast charging power bank 800

[0040] Battery 82

[0041] Fast Charge Adapter 900

[0042] AC-DC conversion module 92

[0043] Steps 1001-1003

[0044] The following specific implementation methods will further illustrate the present application in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0045] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. The drawings are only for illustrative purposes and represent only schematic diagrams, which cannot be understood as limitations on the present application. Obviously, the described embodiments are only some embodiments of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present application.

[0046] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as those commonly understood by those skilled in the art. The terms used in this application in the specification are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0047] The following is a brief introduction to the fast charging circuit in the existing fast charging power supply equipment (not shown).

[0048] like Figure 1As shown, the existing fast charging circuit 100 generally includes a voltage conversion module 11, a fast charging control module 12, and a USB interface 13. Among them, the USB interface 13 is used to electrically connect to an external device 200, such as a mobile phone, through a USB charging cable 21. The voltage conversion module 11 is electrically connected to the VBUS pin of the USB interface 13, and outputs a charging voltage to the external device 200 through the VBUS pin of the USB interface 13. Under normal circumstances, for example, when the external device 200 is not inserted into the USB interface 13, the voltage conversion module 11 outputs a preset normal charging voltage Vout, such as a normal charging voltage of 5V to the VBUS pin of the USB interface 13. Among them, the voltage conversion module 11 may be a DC-DC BOOST boost module. It can be understood that the fast charging control module 12, or the voltage conversion module 11 and the fast charging control module 12 can be arranged in a fast charging chip.

[0049] The fast charge control module 12 is electrically connected to the voltage conversion module 11 and the USB interface 13, respectively. When the external device 200 is inserted into the USB interface 13, the voltage conversion module 11 outputs a preset normal charging voltage Vout to charge the external device 200. At this time, the external device 200 enters the normal charging mode. After the external device 200 is inserted into the USB interface 13, the fast charge control module 12 can communicate with the external device 200 through the USB interface 13 to obtain the fast charge protocol signal of the external device 200.

[0050] The fast charge control module 12 is also used to identify the fast charge voltage request of the external device 200 according to the fast charge protocol signal, and control the voltage conversion module 11 to output the corresponding fast charge voltage to the VBUS pin of the USB interface 13 according to the fast charge voltage request, so as to quickly charge the external device 200. At this time, the external device 200 enters the fast charge mode.

[0051] For example, the external device 200 applies for a 12V fast charge voltage, and the fast charge control module 12 controls the voltage conversion module 11 to output a 12V voltage Vout to the VBUS pin of the USB interface 13, thereby fast charging the external device 200. The fast charge control module 12 can obtain the fast charge protocol signal through the DP pin and the DM pin of the USB interface 13.

[0052] When the USB charging cable 21 is suddenly unplugged from the USB interface 13, or the USB charging cable 21 is suddenly unplugged from the external device 200, the fast charging protocol signal disappears. When the fast charging control module 12 recognizes that the fast charging protocol signal disappears, the fast charging control module 12 controls the voltage conversion module 11 to reduce the output voltage Vout to a preset voltage, such as 5V.

[0053] Since the connecting pins of the USB interface 13 and the USB input interface of the USB charging cable 21 have a certain length in terms of mechanical structure, it takes a certain amount of time to separate the two. Figure 2 As shown, the process of unplugging the external device 200 during the fast charging process is: start to unplug the external device 200 at time t1, and completely unplug the external device 200 at time t2. That is to say, the time △T1 required from the external device 200 being unplugged to being completely unplugged is approximately 10 to 20ms. From the time the external device 200 is unplugged to the time the fast charging control module 12 recognizes that the fast charging protocol signal disappears, the response time required by the fast charging control module 12 is also approximately 10 to 20ms. In other words, the response time of the fast charging control module 12 recognizing that the fast charging protocol signal disappears is approximately equal to the time required for the external device 200 to be completely unplugged. In this way, when the fast charging control module 12 controls the voltage conversion module 11 to reduce the output voltage Vout to the preset voltage, the external device 200 has been completely unplugged.

[0054] like Figure 2 As shown, within the time △T1, for example, within 10ms, the fast charge control module 12 has not yet recognized that the fast charge protocol signal disappears, and the output voltage Vout of the voltage conversion module 11 is maintained at the set value of 12V. The external device 200 is completely unplugged at time t2. Due to the sudden change of the output load current of the voltage conversion module 11 (the external device 200 is suddenly unplugged, which is equivalent to the output load current suddenly becoming 0), and the power supply transient response characteristics of the fast charge power supply device, the output voltage Vout of the voltage conversion module 11 will overshoot. In severe cases, this overshoot voltage will rise to about 15.5V, and the overshoot amplitude △V1=3.5V, which seriously affects the safety of the fast charge power supply device.

[0055] The general approach to solving this problem is to reduce the amplitude of the overshoot voltage by improving the transient response of the voltage conversion module 11, for example, by increasing the capacity of the filter capacitor Cout, or by changing the analog circuit parameters of the voltage conversion module 11 itself (for example, by increasing the DC-DC switching frequency, or by changing the control loop parameters, etc.). However, among the existing methods for improving the overshoot voltage, increasing the capacity of the filter capacitor Cout will increase the cost of the fast charging power supply device, and the method of modifying the analog circuit parameters of the voltage conversion module 11 itself is more complicated and difficult to implement.

[0056] In response to the above-mentioned problems existing in the prior art, the embodiments of the present application provide a fast charging protection circuit and method, as well as a fast charging mobile power supply and a fast charging adapter having the fast charging protection circuit, which can detect the unplugging action of the external device in advance and quickly in advance when the external device is suddenly unplugged during the fast charging process, and reduce the output voltage in advance before the external device is completely unplugged, thereby effectively reducing the overshoot amplitude of the output voltage and improving the safety of the fast charging mobile power supply / fast charging adapter.

[0057] Figure 3 This is a functional module diagram of a fast charging protection circuit provided in the first embodiment of the present application. Figure 3 As shown, the fast charge protection circuit 300 includes a voltage conversion module 31, a fast charge control module 32, a USB interface 33, and a plug detection module 34. For specific technical details of the voltage conversion module 31, the fast charge control module 32, and the USB interface 33, please refer to the previous Figure 1 The specific description of the voltage conversion module 11, the fast charge control module 12, and the USB interface 13 is not repeated here to save space and avoid repetition. It can be understood that part or all of the structures in the voltage conversion module 31, the fast charge control module 32, and the plug detection module 34 can be set in the fast charge chip.

[0058] In this embodiment, the plug-in detection module 34 is electrically connected to the USB interface 33, and is used to detect the fast charge protocol signal in real time through the USB interface 33, and output a pull-out signal when the fast charge protocol signal disappears. The fast charge control module 32 is also electrically connected to the output end of the plug-in detection module 34, and the fast charge control module 32 is also used to control the voltage conversion module 31 to reduce the output voltage from the fast charge voltage to a preset voltage, such as a 5V normal charging voltage, when receiving the pull-out signal.

[0059] The fast charging protocol signal disappears when the external device 200 begins to be unplugged. The fast charging protocol signal includes but is not limited to the DP / DM signal of the fast charging protocol and / or the CC1 / CC2 signal of the Type-C protocol.

[0060] In this embodiment, the plug-in detection module 34 is electrically connected to a preset pin of the USB interface 33 for obtaining the fast charging protocol signal. The plug-in detection module 34 is used to detect the voltage change of the preset pin in real time, and determine whether the voltage change of the preset pin meets the preset condition, and when the voltage change of the preset pin meets the preset condition, determine that the external device 200 begins to be unplugged and the fast charging protocol signal disappears, and output the unplugging signal.

[0061] In this embodiment, the USB interface 33 includes a USB TYPE-A interface and a USB TYPE-C interface, and the preset pin is the DP pin of the USB TYPE-A interface or the CC1 / CC2 pin of the USB TYPE-C interface.

[0062] The plug-in detection module 34 includes a comparison module 341, an input end of the comparison module 341 is electrically connected to a preset pin of the USB interface 33, and the comparison module 341 is used to compare the voltage of the preset pin of the USB interface 33 with a preset reference voltage to determine whether the voltage change of the preset pin of the USB interface 33 meets the preset condition.

[0063] In this embodiment, the plug-in detection module 34 also includes a debounce module 342, and the debounce module 342 is electrically connected between the output end of the comparison module 341 and the fast charge control module 32. The debounce module 342 is used to transmit the unplug signal to the fast charge control module 32 when the unplug signal is continuously received within a preset time. The preset time is less than the time required for the external device to be completely unplugged from the beginning. The preset time can be set to 1ms, for example. It can be understood that by setting the debounce time of 1ms by setting the debounce module 342, it is possible to prevent erroneous operations caused by interference such as glitches.

[0064] In this embodiment, the time required from the plug-in detection module 34 detecting the disappearance of the fast charge protocol signal to the voltage conversion module 31 starting to reduce the output voltage Vout is less than the time required for the external device 200 to be completely unplugged from the beginning. In this way, when the voltage conversion module 31 starts to reduce the output voltage, the electrical connection between the USB interface 33 and the external device 200 is not completely disconnected, and the voltage conversion module 31 continues to output the charging voltage to the external device 200 through the USB interface 33. In other words, the fast charge control module 32 controls the voltage conversion module 31 to reduce the output voltage before the external device 200 is completely unplugged.

[0065] The fast charging protection circuit 300 proposed in the present application detects the fast charging protocol signal in real time through the plug-in detection module 34 during the fast charging process, has a fast response speed, can quickly detect the unplugging action of the external device 200 in advance, and before the external device 200 is completely unplugged, that is, before the external device 200 is completely electrically disconnected from the fast charging mobile power supply or the fast charging adapter, the output voltage of the voltage conversion module 31 is reduced in advance, thereby effectively reducing the overshoot amplitude of the output voltage, thereby improving the reliability of the fast charging mobile power supply or the fast charging adapter.

[0066] Figure 4 for Figure 3 A circuit structure diagram of a fast charge protection circuit is shown in FIG. Figure 4 As shown, the fast charge protection circuit 400 includes a voltage conversion module 41, a fast charge control module 42, a USB interface 43, and a plug-in detection module 44. Figure 3 The voltage conversion module 31 , fast charge control module 32 , USB interface 33 , and plug-in detection module 34 shown correspond to each other one by one.

[0067] In this embodiment, the USB interface 43 is a USB TYPE-A interface, including a VBUS pin, a DM pin, a DP pin, and a GND pin. The preset pin is the DP pin of the USB interface.

[0068] The comparison module includes a comparator 441, which includes two input terminals, one of which is electrically connected to the DP pin of the USB interface 43, and the other is used to receive a first reference voltage. The output terminal of the comparator 441 is electrically connected to the fast charging control module 42 through the de-jitter module 442.

[0069] Figure 5 The pin structures of two USB interfaces are shown in FIG. Figure 5The (A) structure is the pin structure of the USB TYPE-A interface. Figure 5 The structure (B) in the figure is the pin structure of the USB TYPE-C interface. Due to the special structure of the USB interface, the VBUS pin and GND pin are mechanically longer than the DP / DM pin and CC1 / CC2 pin.

[0070] For the USB interface 33, when the USB charging cable 21 is unplugged, the DP / DM / CC1 / CC2 pins of the two will be disconnected first, at which time the fast charging protocol signal disappears, and then the VBUS / GND pins are disconnected, and this time interval is generally about 10-20ms. In other words, the moment when the DP / DM / CC1 / CC2 pins are disconnected corresponds to the moment when the external device 200 begins to be unplugged, and the moment when the VBUS / GND pins are disconnected corresponds to the moment when the external device 200 is completely unplugged.

[0071] For the USB TYPE-A interface, when an external device 200 is inserted, according to the characteristics of the fast charging protocol, when the fast charging connection is successful, the voltage on the DP pin is generally above 0.325V. When the external device 200 is unplugged, that is, the fast charging connection is disconnected, the voltage on the DP pin will be pulled down to less than 0.325V.

[0072] In this embodiment, the comparator 441 is used to output the unplugging signal when the voltage of the DP pin is lower than the first reference voltage, that is, the preset condition is that the voltage of the DP pin is lower than the first reference voltage. The first reference voltage can be set to 0.325V. In this way, when it is detected that the voltage of the DP pin is less than 0.325V and lasts for more than 1ms (in order to prevent interference such as glitches, a debounce time of 1ms is set), it can be determined that the external device 200 is unplugged.

[0073] In one embodiment, Figure 4 As shown, the positive input terminal of the comparator 441 is electrically connected to the DP pin of the USB interface 43, and the negative input terminal receives a first reference voltage of 0.325V. According to the working principle of the comparator, when the external device 200 is in a fast charging state, the voltage of the DP pin is higher than 0.325V, and the comparator outputs a high level; when the external device 200 is unplugged, the voltage of the DP pin is lower than 0.325V, and the comparator 441 outputs a low level. That is to say, in one embodiment, the unplug signal is a low level signal.

[0074] Optionally, in another embodiment, the negative input terminal of the comparator 441 is electrically connected to the DP pin of the USB interface 43, and the positive input terminal receives a first reference voltage of 0.325 V. It can be understood that in the another embodiment, the unplug signal is a high level signal.

[0075] Figure 6 for Figure 3 Another circuit structure diagram of the fast charge protection circuit shown in FIG. Figure 6 As shown, the fast charge protection circuit 500 includes a voltage conversion module 51, a fast charge control module 52, a USB interface 53, and a plug-in detection module 54. Figure 3 The voltage conversion module 31 , fast charge control module 32 , USB interface 33 , and plug-in detection module 34 shown correspond to each other one by one.

[0076] In this embodiment, the USB interface 53 is a USB TYPE-C interface, including a VBUS pin, a DM pin, a DP pin, a CC1 pin, a CC2 pin, and a GND pin. The preset pins are the CC1 pin and the CC2 pin of the USB interface.

[0077] The comparison module includes a first comparator 5411 and a second comparator 5412, wherein the first comparator 5411 includes two input terminals, one of which is electrically connected to the CC1 pin of the USB interface 53, and the other input terminal is used to receive a second reference voltage. The second comparator 5412 includes two input terminals, one of which is electrically connected to the CC2 pin of the USB interface 53, and the other input terminal is used to receive a third reference voltage.

[0078] For the USB TYPE-C interface, when an external device 200 is inserted, according to the characteristics of the fast charging protocol, when the fast charging connection is successful, the voltage on the CC1 pin or the CC2 pin is generally lower than 2V. When the external device 200 is unplugged, that is, when the fast charging connection is disconnected, the voltage on the CC1 pin or the CC2 pin will be pulled up to 3.3V.

[0079] In this embodiment, the first comparator 5411 is used to output the unplugging signal when the voltage of the CC1 pin is higher than the second reference voltage. The second comparator 5412 is used to output the unplugging signal when the voltage of the CC2 pin is higher than the third reference voltage.

[0080] The second reference voltage and the third reference voltage may both be set to 2.9 V. Therefore, by detecting and determining whether the voltage of the CC1 pin or the CC2 pin is higher than 2.9 V, it can be determined whether the external device 200 is unplugged.

[0081] The plug-in detection module 54 also includes a logic gate circuit 543, and the logic gate circuit 543 includes two input terminals, one of which is electrically connected to the output terminal of the first comparator 5411, and the other input terminal is electrically connected to the output terminal of the second comparator 5412. The output terminal of the logic gate circuit 543 is electrically connected to the fast charge control module 52, and the logic gate circuit 543 is used to perform a logical operation on the signals output by the first comparator 5411 and the second comparator 5412, so as to output the unplugging signal when the voltage of the CC1 pin is higher than the second reference voltage, or the voltage of the CC2 pin is higher than the third reference voltage. That is, the preset condition is that the voltage of the CC1 pin is higher than the second reference voltage, or the voltage of the CC2 pin is higher than the third reference voltage.

[0082] In one embodiment, Figure 6 As shown, the positive input terminal of the first comparator 5411 is electrically connected to the CC1 pin of the USB interface 53, and the negative input terminal receives a second reference voltage of 2.9V. The positive input terminal of the second comparator 5412 is electrically connected to the CC2 pin of the USB interface 53, and the negative input terminal receives a third reference voltage of 2.9V. According to the working principle of the comparator, when the external device 200 is in a fast charging state, the voltage of the CC1 pin or the CC2 pin is lower than 2.9V, and the first comparator 5411 and the second comparator 5412 both output a low level; when the external device 200 is unplugged, the voltage of the CC1 pin or the CC2 pin is higher than 2.9V, and the first comparator 5411 and the second comparator 5412 both output a high level. That is to say, in one embodiment, the unplugging signal is a high level signal.

[0083] In one embodiment, the logic gate circuit 543 is an OR gate, which is used to perform a logical OR operation on the signals output by the first comparator 5411 and the second comparator 5412, so as to output the high level signal, i.e., the pull-out signal, when the voltage of the CC1 pin is higher than the second reference voltage, or the voltage of the CC2 pin is higher than the third reference voltage.

[0084] In another embodiment, the negative input terminal of the first comparator 5411 is electrically connected to the CC1 pin of the USB interface 53, and the positive input terminal receives a second reference voltage of 2.9 V. The negative input terminal of the second comparator 5412 is electrically connected to the CC2 pin of the USB interface 53, and the positive input terminal receives a third reference voltage of 2.9 V. It can be understood that in the another embodiment, the unplug signal is a low level signal.

[0085] In the other embodiment, the logic gate circuit 543 is an AND gate, which is used to perform a logic AND operation on the signals output by the first comparator 5411 and the second comparator 5412, so as to output the low level signal, i.e., the pull-out signal, when the voltage of the CC1 pin is higher than the second reference voltage, or the voltage of the CC2 pin is higher than the third reference voltage.

[0086] like Figure 6 As shown, the plug-in detection module 54 includes two de-jitter modules 5421 and 5422, wherein one of the de-jitter modules 5421 is electrically connected between the output end of the first comparator 5411 and one of the input ends of the logic gate circuit 543, and the other de-jitter module 5422 is electrically connected between the output end of the second comparator 5412 and the other input end of the logic gate circuit 543.

[0087] In another embodiment, the plug-in detection module 54 may include a de-jitter module, which is electrically connected between the output end of the logic gate circuit 543 and the fast charge control module 52 .

[0088] Figure 7 for Figure 3 , Figure 4 or Figure 6 The schematic diagram shows a voltage overshoot of the output voltage Vout of the fast charge protection circuit when the external device 200 is unplugged.

[0089] As mentioned above, the VBUS pin and GND pin of the USB interface are mechanically longer than the DP / DM pin and CC1 / CC2 pin. Figure 7 As shown, the process of unplugging the external device 200 during fast charging is: start to unplug the external device 200 at time t1, at this time, the DP / DM / CC1 / CC2 pins of the USB interface 33 and the DP / DM / CC1 / CC2 pins of the USB charging cable 21 of the external device 200 are disconnected, and the fast charging protocol signal disappears; completely unplug the external device 200 at time t2, at this time, the VBUS / GND pins of the USB interface 33 and the VBUS / GND pins of the USB charging cable 21 are disconnected.

[0090] During the process of unplugging the external device 200, when the DP / DM / CC1 / CC2 pins of the USB interface 33 and the DP / DM / CC1 / CC2 pins of the USB charging cable 21 are disconnected, the fast charging protocol signal disappears. After a delay of ΔT2, such as a de-bounce time of 1ms, at time t3, the fast charging control module 32 controls the voltage conversion module 31 to reduce the output voltage Vout. At this time, since ΔT2<ΔT1, the VBUS / GND pin on the USB interface 33 and the VBUS / GND pin of the USB charging cable 21 are not disconnected, and the external device 200 continues to draw current from the VBUS pin. Therefore, the output voltage Vout of the voltage conversion module 31 will not overshoot. Please refer again. Figure 3 The output end of the voltage conversion module 31 is connected to the ground through the filter capacitor Cout. It can be understood that although the fast charging control module 32 controls the voltage conversion module 31 to reduce the output voltage Vout from 12V to 5V, due to the presence of the filter capacitor Cout, the output voltage Vout will not undergo a voltage mutation, that is, it will not suddenly change from the fast charging voltage of 12V to the normal voltage of 5V, but will start to linearly decrease from the fast charging voltage of 12V.

[0091] When the external device 200 or the USB charging cable 21 is completely unplugged, the output load current of the voltage conversion module 31 suddenly becomes 0, and the output voltage Vout starts to surge due to transient response. However, since the output voltage Vout at this time has been continuously reduced for a period of time ΔT3=ΔT1-ΔT2, the voltage value of the output voltage Vout has been reduced a lot, and the overshoot voltage will no longer surge to the original overshoot voltage value when the output voltage is 12V or 9V.

[0092] Taking the fast charging voltage as 12V as an example, in a fast charging power supply device (such as a fast charging mobile power supply or a fast charging adapter) that does not use the fast charging protection circuit of the present application, if Figure 2 As shown, the overshoot voltage can reach 15.5V, and the overshoot amplitude ΔV1 is 3.5V. In contrast, in the fast charging structure using the fast charging protection circuit of the present application, as Figure 7 As shown, the overshoot voltage is 13.2V, the overshoot amplitude ΔV2 is 1.2V, and the overshoot amplitude is greatly reduced.

[0093] It can be seen that compared with the existing fast charging circuit, the fast charging protection circuit proposed in the present application determines in advance the unplugging action of the external device by real-time detection of the DP signal on the USB interface, or the voltage characteristics of the CC1 and CC2 signals during the fast charging process, and reduces the output voltage of the boost circuit to 5V in advance before the external device and the fast charging mobile power supply / fast charging adapter are completely electrically disconnected. In this way, the output voltage of the boost circuit will be lower than the initial fast charging voltage. Even when the boost transient response is not improved, the overshoot amplitude of the output voltage Vout can be effectively reduced, thereby improving the reliability of the fast charging mobile power supply / fast charging adapter.

[0094] In addition, the fast charging protection circuit proposed in the present application detects the fast charging protocol signal through the plug-in detection module, has a fast response speed, and does not need to improve the boost transient response by increasing the capacity of the filter capacitor at the output end or changing the analog circuit parameters of the boost circuit itself. It can achieve the purpose of effectively reducing the overshoot amplitude of the output voltage Vout, thereby achieving a significant reduction in the overshoot voltage amplitude in a low-cost way.

[0095] Figure 8 The functional module diagram of a fast charging protection circuit provided in the second embodiment of the present application. The fast charging protection circuit 600 includes a USB interface 61 and a fast charging chip 62. Figure 8 As shown, in this embodiment, the fast charging chip 62 includes a voltage conversion module 621, a fast charging control module 622, and a plug detection module 623. The voltage conversion module 621, the fast charging control module 622, and the plug detection module 623 are all electrically connected to the USB interface 61. The USB interface 61, the voltage conversion module 621, the fast charging control module 622, and the plug detection module 623 are electrically connected to the USB interface 61. Figure 3 The USB interface 33, the voltage conversion module 31, the fast charge control module 32, and the plug detection module 34 are shown in one-to-one correspondence. For specific technical details of the USB interface 61, the voltage conversion module 621, the fast charge control module 622, and the plug detection module 623, please refer to the previous Figure 3 The specific descriptions of the USB interface 33, the voltage conversion module 31, the fast charge control module 32, and the plug detection module 34 are not repeated here to save space and avoid repetition.

[0096] Fig. 9 A schematic diagram of the functional modules of a fast charging power supply device provided in the embodiment of the present application. Fig. 9As shown, the fast charging power supply device 700 includes a power input interface 71 and a fast charging protection circuit 72. The power input interface 71 is electrically connected to the fast charging protection circuit 72, and the power input interface 71 is used to receive an external power supply, such as 220V AC mains, to provide input voltage to the fast charging protection circuit 72. The fast charging protection circuit 72 is used to charge the external device 200.

[0097] Wherein, the fast charge protection circuit 72 may correspond to Figure 3 , Figure 4 , Figure 6 or Figure 8 The fast charge protection circuits 300, 400, 500, and 600 shown in FIG. 7 are shown in FIG. 7 . For specific technical details of the fast charge protection circuit 72, please refer to the previous description of the fast charge protection circuit 72. Figure 3 , Figure 4 , Figure 6 or Figure 8 The specific descriptions of the fast charging protection circuits 300 , 400 , 500 , and 600 shown are not repeated here to save space and avoid repetition.

[0098] The fast charging power supply device 700 may be Fig.10 The fast charging mobile power bank 800 or Fig.11 The fast charging adapter 900 and other devices shown.

[0099] Fig.10 This is a functional module diagram of a fast-charging mobile power supply provided in the embodiment of the present application. Fig.10 As shown, the fast charging mobile power supply 800 includes a power input interface 81, a battery 82 and a fast charging protection circuit 83. The fast charging protection circuit 83 may correspond to Figure 3 , Figure 4 , Figure 6 or Figure 8 The fast charge protection circuits 300, 400, 500, and 600 shown. For the specific technical details of the fast charge protection circuit 83, please refer to the previous detailed description of the fast charge protection circuits 300, 400, 500, and 600. In order to save space and avoid repetition, they will not be repeated here.

[0100] The power input interface 81 is used to receive an external power source, such as a 220V AC mains. The battery 82 is electrically connected to the power input interface 81 and the fast charge protection circuit 83, respectively, and the battery 82 is used to receive the input voltage of the external power source for charging. The voltage conversion module of the fast charge protection circuit 83 is used to convert the voltage of the battery 82 into a preset voltage or a fast charge voltage corresponding to the fast charge protocol signal, thereby charging the external device.

[0101] The fast-charging mobile power supply proposed in the present application, by adopting the fast-charging protection circuit 83, can achieve a significant reduction in the amplitude of the overshoot voltage with a simple circuit design at low cost, and has high reliability.

[0102] Fig.11 This is a functional module diagram of a fast charging adapter provided in an embodiment of the present application. Fig.11 As shown, the fast charging adapter 900 includes a power input interface 91, an AC-DC conversion module 92, and a fast charging protection circuit 93. The fast charging protection circuit 93 may correspond to Figure 3 , Figure 4 , Figure 6 or Figure 8 The fast charge protection circuits 300, 400, 500, and 600 shown. For the specific technical details of the fast charge protection circuit 93, please refer to the previous detailed description of the fast charge protection circuits 300, 400, 500, and 600. In order to save space and avoid repetition, they will not be repeated here.

[0103] Among them, the power input interface 91 is used to receive an external power supply, such as a 220V AC mains. The AC-DC conversion module 92 is electrically connected to the power input interface 91 and the fast charging protection circuit 93, respectively, and the AC-DC conversion module 92 is used to convert the input voltage of the external power supply into a DC voltage. The voltage conversion module of the fast charging protection circuit 93 can be used to convert the DC voltage into a preset voltage or a fast charging voltage corresponding to the fast charging protocol signal, thereby charging an external device.

[0104] The fast charging adapter proposed in the present application, by adopting the fast charging protection circuit 93, can achieve a significant reduction in the amplitude of the overshoot voltage with a low-cost simple circuit design and has high reliability.

[0105] Fig.12 A flowchart of a fast charging protection method provided in an embodiment of the present application. The fast charging protection method can be applied to Figure 3 , Figure 4 , Figure 6 or Figure 8 In the fast charging protection circuits 300, 400, 500, and 600 shown.

[0106] In this embodiment, if Fig.12 As shown, the fast charging protection method includes the following steps.

[0107] Step 1001, during the fast charging process, the fast charging protocol signal is detected in real time through the plug-in detection module.

[0108] In this implementation, the step 1001 may specifically include:

[0109] During the fast charging process, the plug-in detection module detects in real time the voltage change of the preset pin of the USB interface for obtaining the fast charging protocol signal;

[0110] Determining whether the voltage change of the preset pin meets a preset condition; and

[0111] When it is detected that the voltage change of the preset pin meets the preset condition, it is determined that the external device begins to be unplugged and the fast charging protocol signal disappears.

[0112] In this implementation, the USB interface includes a USB TYPE-A interface and a USB TYPE-C interface, and the preset pin is a DP pin of the USB TYPE-A interface or a CC1 / CC2 pin of the USB TYPE-C interface.

[0113] The step of determining whether the voltage change of the preset pin meets the preset condition may specifically include: comparing the voltage of the preset pin of the USB interface with a preset reference voltage to determine whether the voltage change of the preset pin of the USB interface meets the preset condition.

[0114] Step 1002: When the plug-in detection module detects that the fast charging protocol signal disappears, the plug-in detection module outputs a pull-out signal.

[0115] Step 1003 , controlling the voltage conversion module to reduce the output voltage from the fast charge voltage to a preset voltage according to the unplugging signal.

[0116] Among them, the time required from the plug-in detection module detecting the disappearance of the fast charging protocol signal to the voltage conversion module starting to reduce the output voltage is less than the time required for the external device to be completely unplugged from the beginning.

[0117] The specific technical details of steps 1001-1003 of this embodiment can be referred to Figure 3-Figure 8 The description of the relevant technical details of the illustrated implementation manner will not be repeated here.

[0118] The fast charging protection method proposed in the present application detects the fast charging protocol signal in real time through the plug-in detection module during the fast charging process, so that the unplugging action of the external device can be detected quickly in advance, and the output voltage of the voltage conversion module can be reduced in advance before the external device is completely unplugged, thereby effectively reducing the overshoot amplitude of the output voltage, thereby improving the reliability of fast charging power supply equipment, such as fast charging mobile power supplies or fast charging adapters.

[0119] Finally, it should be noted that the above implementation modes are only used to illustrate the technical solution of the present application and are not intended to limit it. Although the present application has been described in detail with reference to the above preferred implementation modes, a person of ordinary skill in the art should understand that the technical solution of the present application may be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present application.

Claims

1. A fast charging protection method, characterized in that: The fast charging protection method comprises: During the fast charging process, the fast charging protection circuit detects the fast charging protocol signal in real time; When the fast charge protocol signal disappears, the fast charge protection circuit outputs an unplug signal, wherein the fast charge protocol signal disappears when the external device begins to be unplugged; and Control the voltage conversion module of the fast charge protection circuit according to the pull-out signal to reduce the output voltage from the fast charge voltage to a preset voltage; Among them, the time required from detecting that the fast charging protocol signal disappears to the time when the voltage conversion module starts to reduce the output voltage is less than the time required for the external device to be completely unplugged from the beginning.

2. The fast charge protection method according to claim 1, characterized in that: The fast charge protection circuit detecting the fast charge protocol signal includes: By real-time detection of voltage changes of a preset pin of the USB interface for obtaining the fast charging protocol signal; Determining whether the voltage change of the preset pin meets a preset condition; and When it is detected that the voltage change of the preset pin meets the preset condition, it is determined that the external device begins to be unplugged and the fast charging protocol signal disappears.

3. The fast charge protection method according to claim 2, characterized in that: The USB interface includes a USB TYPE-A interface and a USB TYPE-C interface, and the preset pin is a DP pin of the USB TYPE-A interface or a CC1 or CC2 pin of the USB TYPE-C interface; Determining whether the voltage change of the preset pin meets a preset condition includes: The voltage of the preset pin of the USB interface is compared with a preset reference voltage to determine whether a voltage change of the preset pin of the USB interface meets the preset condition.

4. The fast charge protection method according to claim 1, characterized in that: The fast charge protection circuit comprises: USB interface, used for electrical connection with external devices; A voltage conversion module, electrically connected to the USB interface; a fast charge control module, electrically connected to the voltage conversion module and the USB interface respectively, the fast charge control module being used to obtain the fast charge protocol signal of the external device through the USB interface, and to identify the fast charge voltage request of the external device according to the fast charge protocol signal, and to control the voltage conversion module to output a corresponding fast charge voltage to the USB interface according to the fast charge voltage request, so as to quickly charge the external device; and A plug-in detection module, electrically connected to the USB interface, for detecting the fast charge protocol signal through the USB interface, and outputting a pull-out signal when it is detected that the fast charge protocol signal disappears, wherein the fast charge protocol signal disappears when the external device is unplugged; The fast charge control module is also electrically connected to the output end of the plug-in detection module. The fast charge control module is also used to control the voltage conversion module to reduce the output voltage from the fast charge voltage to a preset voltage when receiving the unplug signal.

5. The fast charge protection method according to claim 4, characterized in that: The plug-in detection module is electrically connected to a preset pin of the USB interface for obtaining the fast charging protocol signal. The plug-in detection module is used to detect the voltage change of the preset pin in real time, and determine whether the voltage change of the preset pin meets the preset condition, and when the voltage change of the preset pin meets the preset condition, determine that the external device begins to be unplugged and the fast charging protocol signal disappears, and output the unplugging signal, wherein the preset voltage is 5V.

6. The fast charge protection method according to claim 5, characterized in that: The plug-in detection module includes a comparison module, an input end of the comparison module is electrically connected to a preset pin of the USB interface, and the comparison module is used to compare the voltage of the preset pin of the USB interface with a preset reference voltage to determine whether the voltage change of the preset pin of the USB interface meets the preset condition.

7. The fast charge protection method according to claim 6, characterized in that: The plug-in and unplug detection module also includes a de-jitter module, which is electrically connected between the output end of the comparison module and the fast charging control module. The de-jitter module is used to transmit the unplugging signal to the fast charging control module when the unplugging signal is continuously received within a preset time length, wherein the preset time length is less than the time required for the external device to be completely unplugged from the beginning.

8. The fast charge protection method according to claim 7, characterized in that: The USB interface is a USB TYPE-C interface, including a VBUS pin, a DM pin, a DP pin, a CC1 pin, a CC2 pin, and a GND pin; the preset pins are the CC1 pin and the CC2 pin of the USB interface; The comparison module comprises: a first comparator, comprising two input terminals, one of which is electrically connected to the CC1 pin of the USB interface, and the other input terminal of the first comparator is used to receive a second reference voltage, wherein the first comparator is used to output the unplugging signal when the voltage of the CC1 pin is higher than the second reference voltage; and A second comparator, comprising two input terminals, one of which is electrically connected to the CC2 pin of the USB interface, and the other input terminal of the second comparator is used to receive a third reference voltage, wherein the second comparator is used to output the unplug signal when the voltage of the CC2 pin is higher than the third reference voltage; The plug-in and unplug detection module also includes a logic gate circuit, which includes two input ends, one of the input ends of the logic gate circuit is electrically connected to the output end of the first comparator, and the other input end of the logic gate circuit is electrically connected to the output end of the second comparator, and the output end of the logic gate circuit is electrically connected to the fast charging control module. The logic gate circuit is used to perform logical operations on the signals output by the first comparator and the second comparator to output the unplugging signal when the voltage of the CC1 pin is higher than the second reference voltage, or the voltage of the CC2 pin is higher than the third reference voltage.

9. The fast charge protection method according to claim 8, characterized in that: The plug-in detection module includes two de-jitter modules, one of which is electrically connected between the output end of the first comparator and one of the input ends of the logic gate circuit, and the other de-jitter module is electrically connected between the output end of the second comparator and the other input end of the logic gate circuit.

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