Electronic equipment adapter power supply circuit and power supply adapter

Abstract

The invention relates to the technical field of electronics, in particular to an electronic equipment adapter power circuit and a power adapter. The electronic equipment adapter power supply circuit comprises a rectification circuit, a first transistor, a transformer, an optocoupler, a primary side controller, a rectification controller and a protocol controller. And the protocol controller is used for sending detected abnormal state information to the primary side circuit through a preset communication protocol when the circuit is detected to be in an abnormal state, so that the primary side circuit takes corresponding protection measures. According to the adapter power supply circuit provided by the invention, the abnormal state of the circuit can be actively monitored through the protocol controller in the secondary side circuit, and when an abnormal condition occurs, communication with the primary side controller is actively established by adopting the preset protocol, so that the information of the abnormal condition is transmitted to the primary side controller; therefore, the primary side controller can carry out corresponding processing on the abnormal condition, and the safety of the circuit is ensured.

Description

Technical Field

[0001] The present application relates to the field of electronic technology, and in particular to an electronic equipment adapter power circuit and a power adapter. Background Art

[0002] With the development of electronic communication technology, electronic devices have become an indispensable tool in people's lives. With the increase in the charging speed of electronic devices, the safety and reliability of electronic device adapters are also facing new requirements.

[0003] The power supply circuit of the electronic device adapter needs to convert the alternating current of the mains into direct current adapted to the electronic device. Therefore, the adapter power supply circuit usually includes a rectifier circuit and a transformer. In the related art, in order to improve the safety of the adapter power supply circuit, when the secondary circuit of the transformer in the adapter power supply circuit fails or is in an abnormal state, the protocol controller in the secondary circuit can only indirectly rely on triggering the primary controller to disconnect the primary circuit and the secondary circuit, thereby realizing the protection of the adapter power supply circuit. In the scheme provided by the related art, by increasing or decreasing the charging voltage output by the circuit, the primary circuit triggers the overvoltage protection mechanism or the undervoltage protection mechanism, thereby achieving the purpose of protecting the adapter power supply circuit. However, when the overvoltage protection mechanism is triggered, each device in the circuit will be frequently impacted by a large voltage stress, thereby affecting the working life of the circuit. When the undervoltage protection mechanism is triggered, because the output charging voltage is low and the load is dynamically jumping, it is easy to be falsely triggered, thereby affecting the stability of the circuit. Therefore, the adapter power supply circuit provided in the related art still has certain technical defects and has certain room for improvement. Summary of the invention

[0004] The present application provides an electronic device adapter power circuit and a power adapter, which achieve safety protection for the adapter power circuit while ensuring the working life and stability of the adapter power circuit.

[0005] In a first aspect, the present application provides an electronic device adapter power circuit, the electronic device adapter power circuit comprising: a rectifier circuit, a first transistor, a transformer, an optocoupler, a primary side controller, a rectifier controller, and a protocol controller;

[0006] Wherein, the input end of the rectifier circuit is used to connect to the first power supply; the output end of the rectifier circuit is connected to the input end of the primary winding loop of the transformer; the control signal output pin of the primary controller is connected to the control electrode of the first transistor, the first electrode of the first transistor is connected to the same-name end of the primary winding of the transformer, and the second electrode of the first transistor is grounded; the feedback signal collection pin of the primary controller is connected to the first end of the photoreceiver of the optocoupler, and the second end of the photoreceiver of the optocoupler is grounded;

[0007] The rectifier controller is connected in series in the secondary winding loop of the transformer, and the output end of the secondary winding loop is the charging output end of the adapter power circuit; the optocoupler drive pin of the protocol controller is connected to the negative electrode of the light source of the optocoupler, and the positive electrode of the light source of the optocoupler is connected to the positive electrode of the charging output end; the detection pin of the protocol controller is connected to the charging output end; the communication protocol signal pin of the protocol controller is the fast charging protocol signal terminal of the adapter power circuit;

[0008] The protocol controller is used to determine whether there is an abnormality in the current state according to the detection signal collected by the detection pin. If so, the protocol controller controls to increase the current value of the path where the light source of the optical coupler is located, so that the current value of the path where the light receiver is located increases, thereby lowering the voltage value of the feedback signal on the feedback signal pin;

[0009] The primary side controller is used to control the first transistor to turn off when it is detected that the voltage value of the feedback signal on the feedback signal pin is pulled down to zero, so that the voltage value of the charging output terminal is reduced;

[0010] The protocol controller is further used to detect whether the voltage value of the charging output terminal drops to a first voltage threshold value during the process of the voltage value of the charging output terminal decreasing, and if so, control to reduce the current value of the path where the light source is located, so that the current value of the path where the light receiver is located is reduced, thereby increasing the voltage value of the feedback signal on the feedback signal pin;

[0011] The primary side controller is also used to detect whether the voltage value of the feedback signal on the feedback signal pin increases to a second voltage threshold during the increase of the voltage value of the feedback signal. If so, control the first transistor to be turned off or control the turn-off or conduction frequency of the first transistor.

[0012] In one possible design, the primary side controller includes a zero-crossing detection circuit and a zero-crossing detection pin, and the zero-crossing detection circuit is connected to the zero-crossing detection pin;

[0013] The adapter power supply circuit also includes a power taking winding, which is coupled to the secondary winding of the transformer; a first end of the power taking winding is grounded, and a second end of the power taking winding is connected to the zero crossing detection pin;

[0014] The zero-crossing detection circuit is used to detect the voltage value of the second end of the power-taking winding;

[0015] The primary side controller is also used to detect whether the voltage value at the second end of the power taking winding drops to a third voltage threshold value during the process of reducing the current value in the path where the light receiver is located. If so, control the feedback signal pin to be turned on to collect the voltage value of the feedback signal.

[0016] In one possible design, the adapter power circuit includes a first capacitor and a first resistor; the protocol controller includes a first differential signal pin and a second differential signal pin;

[0017] The first differential signal pin is connected to the first end of the first resistor, the second end of the first resistor is connected to the negative electrode of the charging output terminal, the first differential signal pin is also connected to the first end of the first capacitor, and the second end of the first capacitor is grounded; the second differential signal pin is grounded;

[0018] The first differential signal pin and the second differential signal pin are used to sample the current value on the charging output end;

[0019] The protocol controller is further used to determine whether the current value on the charging output end is greater than a first current threshold or less than a second current threshold. If so, it is determined that an abnormality exists in the current state.

[0020] In one possible design, the protocol controller includes a voltage sampling pin, and the voltage sampling pin is connected to the positive electrode of the charging output terminal;

[0021] The protocol controller is further used to collect the voltage value of the charging output terminal through the voltage sampling pin;

[0022] The protocol controller is further used to determine whether the voltage value of the charging output terminal is greater than a fourth voltage threshold or less than a fifth voltage threshold. If so, it is determined that an abnormality exists in the current state.

[0023] In one possible design, the adapter power circuit includes a second resistor;

[0024] The protocol controller comprises a temperature sampling pin, the temperature sampling pin is connected to the first end of the second resistor, and the second end of the second resistor is grounded;

[0025] The protocol controller is used to collect the temperature value in the current environment through the temperature sampling pin, and determine whether the temperature value is greater than a first temperature threshold or less than a second temperature threshold. If so, it is determined that there is an abnormality in the current state.

[0026] In one possible design, the adapter power supply circuit further includes an RCD absorption circuit;

[0027] The input end of the RCD absorption circuit is connected to the same-name end of the primary winding of the transformer, and the output end of the RCD absorption circuit is connected to the opposite-name end of the primary winding; the RCD absorption circuit and the primary winding form the primary winding loop.

[0028] In one possible design, the adapter power circuit further includes a second capacitor and a third capacitor;

[0029] The first output end of the rectifier circuit is connected to the first end of the second capacitor, and the second output end of the rectifier circuit is connected to the second end of the second capacitor; the first output end of the rectifier circuit is also connected to the opposite end of the primary winding;

[0030] The same-name end of the secondary winding is connected to the input end of the rectifier controller, the output end of the rectifier controller is connected to the first end of the third capacitor, and the second end of the third capacitor is connected to the opposite-name end of the secondary winding.

[0031] In one possible design, the adapter power supply circuit further includes a first voltage divider circuit, and the first voltage divider circuit includes at least two voltage divider resistors;

[0032] The first end of the first voltage divider circuit is connected to the second end of the power taking winding, the second end of the first voltage divider circuit is grounded, and the voltage output end of the first voltage divider circuit is connected to the zero crossing detection pin.

[0033] In a second aspect, the present application also provides a power adapter, which includes the adapter power circuit as described above.

[0034] The adapter power supply circuit provided by the first aspect above includes: a rectifier circuit, a first transistor, a transformer, an optocoupler, a primary controller, a rectifier controller and a protocol controller; when an abnormal situation occurs in the circuit, there is no need to increase or decrease the charging voltage output by the circuit, so that the primary circuit triggers the overvoltage protection mechanism or the undervoltage protection mechanism, which will not cause frequent high-voltage shocks to the components in the circuit, thereby ensuring the working life of the circuit; in addition, there will be no false triggering due to dynamic jumps of the load when the charging voltage is low, thereby ensuring the stability of the circuit operation.

[0035] The beneficial effects provided in the above-mentioned second aspect and various possible designs of the above-mentioned second aspect can refer to the beneficial effects brought about by the above-mentioned first aspect and various possible implementation methods of the first aspect, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 A schematic diagram of the power supply circuit structure of an electronic device adapter provided in an embodiment of the present application;

[0037] Figure 2 A schematic diagram of the working process of the adapter power supply circuit provided in an embodiment of the present application in the first working mode;

[0038] Figure 3 A timing diagram of various waveforms of the adapter power circuit provided by an embodiment of the present application in a first working mode;

[0039] Figure 4 A schematic diagram of the working process of the adapter power supply circuit provided in the embodiment of the present application in the second working mode;

[0040] Figure 5 This is a timing diagram of various waveforms of the adapter power circuit provided in an embodiment of the present application in the second working mode. DETAILED DESCRIPTION

[0041] In this application, "at least one" means one or more, and "plurality" means two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone, where A and B can be singular or plural. The character " / " generally indicates that the associated objects before and after are in an "or" relationship. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b, or c alone can represent: a, b, c, a and b, a and c, or a, b, and c, where a, b, and c can be single or multiple. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0042] The directions or positional relationships indicated by terms such as "center", "longitudinal", "lateral", "up", "down", "left", "right", "front", and "back" are based on the directions or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present application and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present application.

[0043] The terms "connected" and "connected" should be understood in a broad sense. For example, the "connected" or "connected" of a circuit structure can refer to not only physical connection, but also electrical connection or signal connection. For example, it can be directly connected, that is, physically connected, or indirectly connected through at least one intermediate element, as long as the circuit is connected, or it can be the internal connection of two elements; signal connection can refer to signal connection through a circuit or through a media medium, such as radio waves. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0044] The transistor in the present application is a three-terminal transistor, and its three terminals are a control electrode, a first electrode, and a second electrode. The transistor can be a bipolar transistor or a field effect transistor, etc. For example, when the transistor is a bipolar transistor, its control electrode refers to the base of the bipolar transistor, the first electrode can be the collector or emitter of the bipolar transistor, and the corresponding second electrode can be the emitter or collector of the bipolar transistor; when the transistor is a field effect transistor, its control electrode refers to the gate of the field effect transistor, the first electrode can be the drain or source of the field effect transistor, and the corresponding second electrode can be the source or drain of the field effect transistor.

[0045] In a circuit protection scheme provided by the related technology, when an abnormality is detected in the circuit, the charging output voltage can be increased by the protocol controller in the secondary circuit to trigger the overvoltage protection mechanism of the primary circuit, so that the primary circuit stops working, thereby protecting the adapter power circuit. However, since the charging output voltage of this technical scheme is too high, the voltage on multiple devices in the circuit will be close to their maximum withstand voltage value. In this way, multiple components in the circuit will be frequently impacted by large voltage stress, which will reduce the stability of each device and affect the life cycle of each component in the circuit, thereby affecting the working life of the adapter power circuit.

[0046] In another circuit protection scheme provided by the related art, when the protocol controller detects that there is an abnormality in the circuit, the protocol controller in the secondary circuit can lower the charging output voltage to trigger the undervoltage protection mechanism of the primary circuit, so that the primary circuit stops working or adjusts the output power, thereby protecting the adapter power circuit. Although this technical solution can avoid the output charging voltage being too high to cause voltage shock to the components in the circuit, thereby affecting the life cycle of the circuit, the technical solution will also bring the following effects due to the low charging output voltage. First, when the output end of the circuit is in a no-load state, the rectifier controller in the circuit does not output the control waveform, so it is difficult for the primary circuit to trigger the undervoltage protection, so the protection effect of this protection scheme is not stable enough. In addition, when the output end of the circuit is in full load and light load conditions, due to the different voltage drops across the transistors in the rectifier controller, when the circuit is in full load and light load conditions, the threshold of the output voltage undervoltage protection in the circuit is deviated, resulting in poor consistency of undervoltage protection under light load and heavy load. Finally, when the charging output voltage of the circuit is too low and the load in the circuit changes dynamically, this may cause the undervoltage protection mechanism of the circuit to be falsely triggered, thereby affecting the stability of the circuit during safety protection.

[0047] In order to overcome the defects in the above-mentioned prior art, the present application provides an electronic device adapter power circuit, which includes a rectifier circuit, a first transistor, a transformer, an optical coupler, a primary controller, a rectifier controller and a protocol controller. The protocol controller is used to collect and monitor whether there is an abnormality in the circuit state in real time, and when it is determined that the circuit state is abnormal, the current value of the path where the light receiver is located is increased by actively adjusting the current value of the path where the light receiver is located, thereby lowering the voltage value of the feedback signal on the feedback signal pin; when the primary controller detects that the voltage value of the feedback signal is pulled down to zero, the first transistor is controlled to be turned off so that the voltage value of the charging output terminal is reduced; the protocol controller is also used to detect whether the voltage value of the charging output terminal drops to a first voltage threshold during the process of reducing the voltage value of the charging output terminal, and if so, the current value of the path where the light source is located is controlled to be reduced, so that the voltage value of the feedback signal on the feedback signal pin is increased; the primary controller is also used to detect whether the voltage value of the feedback signal on the feedback signal pin is increased to a second voltage threshold during the process of increasing the voltage value of the feedback signal, and if so, it is determined that the circuit is abnormal, and the first transistor is controlled to be turned off or the first transistor is controlled to be turned off or turned on. The frequency.

[0048] It can be seen that according to the adapter power supply circuit provided in the present application, the abnormal state of the circuit can be actively monitored by the protocol controller in the secondary circuit, and when an abnormal situation occurs, a pre-set protocol is used to actively establish communication with the primary controller to transmit information about the abnormal situation to the primary controller, so that the primary controller can perform corresponding processing on the primary circuit to ensure the safety of the circuit.

[0049] In addition, compared with the circuits in the related art, the adapter power supply circuit provided in the present application does not need to increase or decrease the charging voltage output by the circuit when an abnormal situation occurs in the circuit, so that the primary circuit triggers the overvoltage protection mechanism or the undervoltage protection mechanism. This will not cause frequent high-voltage shocks to the components in the circuit, thereby ensuring the working life of the circuit; in addition, there will be no false triggering due to dynamic jumping of the load when the charging voltage is low, thereby ensuring the stability of the circuit operation.

[0050] In the field of electronic device adapter power circuits, the adapter power circuit with a USB-A interface is a commonly used adapter circuit. The adapter power circuit with a USB-A interface is widely used in electronic devices with low charging power. For example, the adapter with a USB-A interface is usually used in electronic devices with a charging power below 30W.

[0051] The following takes a USB-A interface type electronic device adapter power circuit as an example to further illustrate the technical solution of the present application.

[0052] Figure 1 For a schematic diagram of the power supply circuit structure of an electronic device adapter provided in an embodiment of the present application, see Figure 1 As shown, the electronic device adapter power circuit provided in this embodiment includes: a rectifier circuit 102, a first transistor 104, a transformer 105, an optical coupler, a primary side controller 101, a rectifier controller 107 and a protocol controller 110. The optical coupler includes a light source 106 and a light receiver 103.

[0053] Among them, the input end of the rectifier circuit 102 is the input end of the adapter power circuit. Generally, the input end of the adapter power circuit includes two wiring terminals, the live wire L and the neutral wire N. The input ends of the live wire L and the neutral wire N are used to connect to the first power supply, for example, the input ends of the live wire L and the neutral wire N are used to connect to the mains. The output end of the rectifier circuit 102 is connected to the input end of the primary winding loop of the transformer 105. The primary winding loop of the transformer 105 is coupled with the secondary winding loop to achieve voltage conversion. In this embodiment, the transformer 105 is mainly used to reduce the input voltage to an adaptive charging voltage. The control signal output pin of the primary controller 101 is connected to the control electrode of the first transistor 104, the first electrode of the first transistor 104 is connected to the same-name end of the primary winding of the transformer 105, and the second electrode of the first transistor 104 is grounded; the feedback signal acquisition pin FB of the primary controller 101 is connected to the first end of the photoreceiver 103 of the optocoupler, and the second end of the photoreceiver 103 of the optocoupler is grounded GND.

[0054] The rectifier controller 107 is connected in series in the secondary winding loop of the transformer 105, and the output end of the secondary winding loop is the charging output end of the adapter power circuit. For details, see Figure 1 As shown, the charging output terminal of the adapter power circuit of this embodiment includes a positive electrode VBUS and a negative electrode GND, and the positive electrode VBUS and the negative electrode GND are used to output the corresponding charging power to charge the electronic device. The optocoupler drive pin OPTO of the protocol controller 110 is connected to the negative electrode of the optocoupler light source 106, and the positive electrode of the optocoupler light source 106 is connected to the positive electrode VBUS in the charging output terminal; each detection pin of the protocol controller 110 is connected to the positive electrode VBUS or the negative electrode GND in the charging output terminal to sample the charging voltage and charging current output by the circuit. In addition, the two communication protocol signal pins DP and DM of the protocol controller 110 are fast charging protocol signal terminals of the adapter power circuit, and the fast charging protocol signal terminals are used for communication between the electronic device and the adapter to realize the intelligent charging process.

[0055] The positive charging output terminal VBUS, the negative charging output terminal GND, and the communication protocol signal pins DP and DM together form a USB_A interface 111, and the USB_A interface 111 is used to connect a USB_A charging head.

[0056] Among them, since the photocoupler light receiver 103 in the primary circuit and the light source 106 of the photocoupler in the secondary circuit are coupled, the feedback signal collection pin FB on the primary controller 101 can determine the current change on the path where the light source 106 is located by collecting the voltage signal at one end of the light receiver 103. Exemplarily, when the current value of the path where the light source 106 of the photocoupler is located increases, the current of the path where the photocoupler light receiver 103 is located will also increase; when the current value of the path where the light source 106 of the photocoupler is located decreases, the current value of the path where the photocoupler light receiver 103 is located will also decrease.

[0057] In some embodiments, the electronic device adapter power circuit also includes a pull-up circuit, the first end of the pull-up circuit is connected to a power supply of a fixed voltage, and the second end of the pull-up circuit is connected to the feedback signal acquisition pin FB through a voltage divider resistor. In this way, due to the existence of the voltage divider resistor, when the current value of the path where the optical receiver 103 of the optocoupler is located increases, the voltage on the voltage divider resistor increases, and correspondingly, the voltage at the point of the feedback signal acquisition pin FB will decrease, or even decrease to zero. For example, the first end of the pull-up circuit is connected to a 3.3V power supply, and as the current value of the path where the optical receiver 103 of the optocoupler is located increases, when the voltage on the voltage divider resistor approaches 3.3V, the voltage at the point of the feedback signal acquisition pin FB is close to zero. On the contrary, when the current value of the path where the optical receiver 103 of the optocoupler is located decreases to a certain value, when the voltage on the voltage divider resistor is very small, the voltage at the point of the feedback signal acquisition pin FB is close to 3.3V. Therefore, the current value of the path where the light source 106 of the optocoupler is located can be controlled to control the current value of the path where the light receiver 103 of the optocoupler is located, thereby adjusting the voltage value at the feedback signal collection pin FB point.

[0058] The primary side controller 101 may output a corresponding control signal to the control electrode of the first transistor 104 to control the on or off state of the first transistor 104, or to control the on or off frequency of the first transistor 104. Figure 1 From the circuit structure shown and the above description, it can be understood that when the primary side controller 101 controls the first transistor 104 to turn off, the primary side circuit stops working. The primary side controller 101 can also control the on or off frequency of the first transistor 104, thereby controlling the magnitude of the charging voltage output by the secondary side circuit.

[0059] During the charging process of the electronic device, the rectifier circuit 102 first rectifies the input sinusoidal AC power into AC power with a positive half-cycle, then transmits the electric energy to the secondary circuit through the transformer 105, and finally rectifies the electrical signal received by the secondary side into a DC signal of a corresponding voltage value through the rectifier controller 107, so as to output it to the electronic device for charging.

[0060] According to the electronic device adapter power supply circuit provided in this embodiment, on the basis of realizing intelligent charging of electronic devices, it also has the functions of circuit abnormal state monitoring and abnormal state protection. Since realizing intelligent charging of electronic devices is the basic function of the circuit of this embodiment, and it is easy for technical personnel in this field to understand it in combination with the above description, the functions and processes of intelligent charging are not described here. The following is a detailed description of the abnormal state monitoring and abnormal state protection functions of the circuit of this application in combination with specific embodiments.

[0061] Figure 2 This is a schematic diagram of the working process of the adapter power circuit provided in the embodiment of the present application in the first working mode, Figure 3 This is a timing diagram of various waveforms of the adapter power circuit provided in an embodiment of the present application in the first working mode.

[0062] Please refer to Figure 2 and Figure 3 As shown, in some examples, the working process of the adapter power circuit in the first working mode includes:

[0063] S201, protocol controller 110, is used to determine whether there is an abnormality in the current state based on the detection signal collected by the detection pin. If so, it controls to increase the current value of the path where the light source 106 of the optocoupler is located, so that the current value of the path where the light receiver 103 is located increases, thereby lowering the voltage value of the feedback signal on the feedback signal pin FB.

[0064] According to the functions of the protocol controller 110 itself, the protocol controller 110 can control the current value of the optocoupler driving pin OPTO, thereby adjusting the current value of the path where the light source 106 of the optocoupler is located.

[0065] S202 , the primary side controller 101 is used to control the first transistor 104 to turn off when it is detected that the voltage value Vfb of the feedback signal on the feedback signal pin FB is pulled down to zero, so as to reduce the voltage value Vout of the charging output terminal.

[0066] It can be understood that when the primary-side controller 101 controls the first transistor 104 to turn off, the primary-side circuit stops working, thereby reducing the voltage value of the charging output terminal.

[0067] See also Figure 3 As shown, in the time period of 0 to t1, the circuit works normally, and the voltage value Vfb of the feedback signal on the feedback signal pin FB is maintained at the voltage value FB1 of normal operation. Generally, in normal operation, Vfb is maintained between 0.6 and 2 V. In the time period of 0 to t1, the primary side controller 101 normally outputs a PWM waveform of a certain frequency, and the PWM waveform is used to drive the first transistor 104 to conduct at a certain operating frequency.

[0068] At time t1, when the protocol controller 110 detects that the circuit is in an abnormal state, it controls the voltage value Vfb of the feedback signal to be pulled down to 0V, and the primary side controller 101 controls the first transistor 104 to be turned off, thereby controlling the primary side circuit to stop working, so that the voltage value Vout of the charging output end is reduced.

[0069] S203, the protocol controller 110, is also used to detect whether the voltage value Vout of the charging output terminal drops to the first voltage threshold Vdd-off during the process of the voltage value Vout of the charging output terminal decreasing. If so, it controls to reduce the current value of the path where the light source 106 is located, so that the current value of the path where the light receiver 103 is located is reduced, thereby increasing the voltage value Vfb of the feedback signal on the feedback signal pin FB.

[0070] Please combine Figure 3 As shown, in the time period t1 to t2, the voltage value Vout of the charging output terminal is continuously reduced, and at time t2, the voltage value Vout of the charging output terminal drops to the first voltage threshold value Vdd-off. At this time, the protocol controller 110 increases the voltage value Vfb of the feedback signal on the feedback signal pin FB by controlling to reduce the current value of the path where the light source 106 is located, and then the primary side controller 101 controls the first transistor 104 to turn on, so that the control primary side starts to work again. At this time, at time t3, the voltage value Vout of the output terminal rises again, and the voltage value Vfb of the feedback signal detected by the primary side controller 101 also gradually rises.

[0071] S204, the primary side controller 101 is also used to detect whether the voltage value Vfb of the feedback signal on the feedback signal pin FB increases to the second voltage threshold FB_Trigger during the increase of the voltage value Vfb of the feedback signal. If so, the first transistor 104 is controlled to be turned off or the turn-off or conduction frequency of the first transistor 104 is controlled.

[0072] In the process of the voltage value Vfb of the feedback signal on the feedback signal pin FB being gradually increased from 0V to the maximum voltage value FB_max, when it is detected that the voltage value Vfb of the feedback signal increases to the second voltage threshold FB_Trigger, it is determined that the protocol controller 110 transmits the abnormal status information of the circuit to the primary controller 101, and the primary controller 101 can take corresponding solutions to achieve safety protection of the circuit.

[0073] When the voltage value Vfb of the feedback signal increases to the second voltage threshold FB_Trigger, the primary controller 101 stops oscillating and pulls the voltage value Vfb of the feedback signal down to 0 V. This is to prepare for the next stage of abnormal state triggering and prevent the output voltage of the circuit from being too high after the voltage value Vfb is directly released, thereby damaging the components in the circuit.

[0074] in, Figure 3 FB_max shown in is the maximum voltage value of the feedback signal preset in the circuit.

[0075] It can be understood that the above method can control the first transistor 104 to be turned off, so that the primary circuit stops working, thereby ensuring the safety of the circuit, or the primary controller 101 can also control the on or off frequency of the first transistor 104, thereby controlling the size of the charging voltage output by the secondary circuit.

[0076] In some embodiments, the primary controller 101 includes a zero-crossing detection circuit and a zero-crossing detection pin ZCD, and the zero-crossing detection circuit is connected to the zero-crossing detection pin ZCD. The adapter power supply circuit also includes a power winding L3, which is coupled to the secondary winding L2 of the transformer; the first end of the power winding L3 is grounded, and the second end of the power winding L3 is connected to the zero-crossing detection pin ZCD.

[0077] The zero-crossing detection circuit in the primary controller 101 is used to detect the voltage value at the second end of the power winding L3 through the zero-crossing detection pin ZCD during the process of the current value of the path where the light receiver 103 is located decreasing.

[0078] It can be understood that since the power winding L3 is coupled with the secondary winding L2, the two have the same voltage variation characteristics, so the voltage signal on the power winding L3 can represent the voltage value Vout at the output end. Therefore, in this embodiment, by detecting the voltage value on the power winding L3, it can be further determined whether the voltage value Vout at the charging output end drops to the first voltage threshold Vdd-off. In addition, the power winding L3 in this embodiment can be coupled to the secondary winding L2 to draw power to power the primary controller 101.

[0079] Figure 4 This is a schematic diagram of the working process of the adapter power circuit provided in the embodiment of the present application in the second working mode, Figure 5 This is a timing diagram of various waveforms of the adapter power circuit provided in an embodiment of the present application in the second working mode.

[0080] Please refer to Figure 4 and Figure 5 As shown, in some examples, the working process of the adapter power circuit in the second working mode includes:

[0081] S401, protocol controller 110, is used to determine whether there is an abnormality in the current state according to the detection signal collected by the detection pin. If so, it controls to increase the current value of the path where the light source 106 of the optocoupler is located, so that the current value of the path where the light receiver 103 is located increases, thereby lowering the voltage value of the feedback signal on the feedback signal pin FB.

[0082] S402 , the primary side controller 101 is used to control the first transistor 104 to turn off when it is detected that the voltage value Vfb of the feedback signal on the feedback signal pin FB is pulled down to zero, so as to reduce the voltage value Vout of the charging output terminal.

[0083] Please combine Figure 4 As shown, in the time period of 0 to t1, the circuit works normally. At time t1, when the protocol controller 110 detects that the circuit is in an abnormal state, the voltage value Vfb of the control feedback signal is pulled down to 0V, and at time t1, the voltage Vzcd detected on the zero-crossing detection pin ZCD is simultaneously detected to drop to 0V. At this time, the primary side controller 101 controls the first transistor 104 to turn off, so that the voltage value Vout at the charging output terminal is reduced.

[0084] S403, the protocol controller 110 is also used to detect whether the voltage value Vout of the charging output terminal drops to the first voltage threshold Vdd-off during the process of the voltage value Vout of the charging output terminal decreasing. If so, it controls to reduce the current value of the path where the light source 106 is located, so that the current value of the path where the light receiver 103 is located is reduced, thereby increasing the voltage value Vfb of the feedback signal on the feedback signal pin FB.

[0085] Please combine Figure 5 As shown, in the time period t1 to t2, the voltage value Vout of the charging output terminal is continuously reduced, and at time t2, the voltage value Vout of the charging output terminal drops to the first voltage threshold value Vdd-off. At this time, the protocol controller 110 increases the voltage value Vfb of the feedback signal on the feedback signal pin FB by controlling the reduction of the current value of the path where the light source 106 is located, and then the primary controller 101 controls the first transistor 104 to be alternately turned on and off, so that the primary winding L1 transmits electric energy to the secondary winding L2. At this time, starting from time t3, the voltage value Vout of the output terminal rises again, and the voltage value Vfb of the feedback signal detected by the primary controller 101 also gradually rises.

[0086] S404, the primary side controller 101 is also used to detect whether the voltage value Vzcd at the second end of the power winding drops to the third voltage threshold Vzcd-uvp during the process of reducing the current value in the path where the light receiver 103 is located. If so, it controls the feedback signal pin FB to be turned on to collect the voltage value Vfb of the feedback signal.

[0087] In other words, before the primary controller 101 detects that the voltage value Vzcd at the second end of the power winding L3 drops to the third voltage threshold Vzcd-uvp, the feedback signal pin FB of the primary controller 101 is in a closed state. At this time, the feedback signal pin FB is not working, which can save energy consumption of the circuit.

[0088] Among them, at time 0, the voltage value Vzcd at the second end of the power winding L3 works in a normal state. At this time, the voltage value Vzcd at the second end of the power winding L3 is Vzcd1. In the time period from 0 to t1, the voltage value Vzcd changes periodically. In the time period from t1 to t2, the voltage value Vzcd is 0V.

[0089] Among them, since the power winding L3 and the secondary winding L2 have the same voltage variation characteristics, in this embodiment, by detecting the voltage value on the power winding L3, it is possible to further determine whether the voltage value Vout at the charging output terminal drops to the first voltage threshold value Vdd-off, which is equivalent to adding a detection process to avoid false triggering of the circuit.

[0090] S405, the primary side controller 101 is also used to detect whether the voltage value Vfb of the feedback signal on the feedback signal pin FB increases to the second voltage threshold FB_Trigger during the increase of the voltage value Vfb of the feedback signal. If so, the first transistor 104 is controlled to be turned off or the turn-off or conduction frequency of the first transistor 104 is controlled.

[0091] It can be understood that, compared with the above embodiment, the zero-crossing detection pin ZCD is added in this embodiment to detect voltage zero-crossing, which is essentially to detect the change trend of the voltage value in the secondary winding L2. Compared with the previous embodiment, the voltage zero-crossing detection is added, which can further avoid the circuit from being triggered incorrectly, so that the circuit protection is safer and more stable. In addition, the above method can be used to control the first transistor 104 to turn off, so that the primary circuit stops working, thereby ensuring the safety of the circuit, or the primary controller 101 can also control the on or off frequency of the first transistor 104, thereby controlling the size of the charging voltage output by the secondary circuit.

[0092] In some embodiments, the adapter power supply circuit also includes a first voltage divider circuit 101, which includes at least two voltage divider resistors; the first end of the first voltage divider circuit 101 is connected to the second end of the power winding L3, the second end of the first voltage divider circuit 101 is grounded, and the voltage output end of the first voltage divider circuit 101 is connected to the zero-crossing detection pin ZCD. The introduction of the first voltage divider circuit 101 can reduce the voltage value on the zero-crossing detection pin ZCD, avoid excessive voltage damaging the device, and thus ensure the working life of the circuit.

[0093] In some embodiments, see Figure 1 As shown, the adapter power circuit also includes a first capacitor C1 and a first resistor R1; the protocol controller 110 includes a first differential signal pin CS+ and a second differential signal pin CS-. The first differential signal pin CS+ is connected to the first end of the first resistor R1, the second end of the first resistor R1 is connected to the negative electrode GND in the charging output terminal, the first differential signal pin CS+ is also connected to the first end of the first capacitor C1, and the second end of the first capacitor C1 is grounded GND; the second differential signal pin CS- is grounded GND.

[0094] The first differential signal pin CS+ and the second differential signal pin CS- are used for differential sampling to sample the current value at the charging output terminal, that is, to collect the current value in the circuit when charging the electronic device. The protocol controller 110 is also used to determine whether the current value at the charging output terminal is greater than the first current threshold or less than the second current threshold, and if so, determine that the current state is abnormal.

[0095] It can be understood that, under one operating condition, when the current value at the charging output terminal is too large, for example, when the current value at the charging output terminal is greater than the first current threshold, it can be determined that there is an abnormality in the current state of the circuit; under another operating condition, when the current value at the charging output terminal is too small, for example, when the current value at the charging output terminal is less than the second current threshold, it can also be determined that there is an abnormality in the current state of the circuit.

[0096] In some embodiments, see Figure 1 As shown, the protocol controller 110 in the power supply circuit of the electronic device adapter also includes a voltage sampling pin VBUS, and the voltage sampling pin VBUS is connected to the positive electrode of the charging output terminal. Among them, the protocol controller 110 is also used to collect the voltage value Vout of the charging output terminal through the voltage sampling pin VBUS. Further, the protocol controller 110 is also used to determine whether the voltage value Vout of the charging output terminal is greater than the fourth voltage threshold or less than the fifth voltage threshold. If so, it is determined that the current state is abnormal.

[0097] It can be understood that, under one operating condition, when the voltage value Vout at the charging output terminal is too high, for example, when the voltage value Vout at the charging output terminal is greater than the fourth voltage threshold, it can be determined that there is an abnormality in the current state of the circuit; under another operating condition, when the voltage value Vout at the charging output terminal is too low, for example, when the voltage value Vout at the charging output terminal is less than the fifth voltage threshold, it can also be determined that there is an abnormality in the current state of the circuit.

[0098] In some embodiments, see Figure 1As shown, the electronic device adapter power circuit also includes a second resistor R2, specifically, the second resistor R2 can be a thermistor, the protocol controller 110 includes a temperature sampling pin NTC, the temperature sampling pin NTC is connected to the first end of the second resistor R2, and the second end of the second resistor R2 is grounded. In this way, the protocol controller 110 can collect the temperature value in the current environment through the second resistor R2.

[0099] Furthermore, the protocol controller 110 is also used to determine whether the temperature value in the current environment is greater than a first temperature threshold or less than a second temperature threshold. If so, it is determined that an abnormality exists in the current state.

[0100] It can be understood that in one working environment of the adapter, if the temperature value of the current environment is too high, continuing to use the adapter to charge the electronic device may cause a dangerous accident due to continuous heat dissipation during charging. Therefore, when it is determined that the temperature value in the current environment is greater than the first temperature threshold, it is determined that there is an abnormality in the current state, and it is necessary to stop charging immediately, or reduce the charging power to reduce the heat generated during charging. In another working environment of the adapter, if the temperature value of the current environment is too low, it may affect the charging efficiency, or using the adapter to charge the electronic device in an environment that is too low may also cause some safety accidents. Therefore, when it is determined that the temperature value in the current environment is less than the second temperature threshold, it is determined that there is an abnormality in the current state of the circuit.

[0101] In this embodiment, the two communication protocol signal pins DP and DM of the protocol controller 110 can also detect in real time whether the communication status between the adapter and the electronic device is abnormal. If there is an abnormality in the communication between the communication protocol signal pins DP and DM and the electronic device, the protocol controller 110 also outputs that there is an abnormality in the current state of the circuit.

[0102] It can be seen that according to the adapter power circuit of this embodiment, when the circuit is in a short circuit, overvoltage, open circuit, abnormal ambient temperature, etc., it can detect that there is an abnormality in the current state of the circuit, thereby triggering the circuit to actively take protective measures to ensure the safety and stability of the circuit.

[0103] In some embodiments, see Figure 1 As shown, the adapter power supply circuit also includes an RCD absorption circuit, which is used to absorb the voltage spike caused by the transformer leakage inductance to prevent the first transistor 104 from being damaged due to overvoltage stress. The input end of the RCD absorption circuit is connected to the same-name end of the primary winding L1 of the transformer 105, and the output end of the RCD absorption circuit is connected to the opposite-name end of the primary winding L1; the RCD absorption circuit and the primary winding constitute the above-mentioned primary winding loop.

[0104] For details, see Figure 1As shown, the RCD absorption circuit includes a third resistor R3, a fourth resistor R4 and a fourth capacitor C4. The fourth capacitor C4 and the third resistor R3 are connected in parallel, the first end of the fourth capacitor C4 is connected to the positive electrode of the output end of the rectifier circuit 102, the first end of the third resistor R3 is also connected to the positive electrode of the output end of the rectifier circuit 102, the second end of the fourth capacitor C4 is connected to the first end of the fourth resistor R4, the second end of the third resistor R3 is also connected to the first end of the fourth resistor R4, the second end of the fourth resistor R4 is connected to the negative electrode of the diode D1, and the positive electrode of the diode D1 is connected to the same end of the primary winding L1.

[0105] In some embodiments, see Figure 1 As shown, the adapter power circuit also includes a second capacitor C2. The positive electrode of the output end of the rectifier circuit 102 is connected to the first end of the second capacitor C2, and the negative electrode of the output end of the rectifier circuit 102 is connected to the second end of the second capacitor C2. At the same time, the negative electrode of the output end of the rectifier circuit 102 is also grounded GND, and the positive electrode of the output end of the rectifier circuit 102 is also connected to the opposite end of the primary winding L1. In this embodiment, the second capacitor C2 is used to filter the rectified voltage signal output by the rectifier circuit 102.

[0106] In some embodiments, see Figure 1 As shown, the adapter power circuit also includes a third capacitor C3; the same-name end of the secondary winding L2 of the transformer 105 is connected to the input end of the rectifier controller 107, the output end of the rectifier controller 107 is connected to the first end of the third capacitor C3, and the second end of the third capacitor C3 is connected to the opposite-name end of the secondary winding L2. In this embodiment, the third capacitor C3 is used to filter the DC signal output by the rectifier controller 107.

[0107] For details, please refer to Figure 1 As shown, the rectifier controller 107 also includes some peripheral devices, for example, the rectifier controller 107 also includes an eighth resistor R8, a ninth resistor R9, a seventh capacitor C7 and an eighth capacitor C8. The connection relationship between the eighth resistor R8, the ninth resistor R9, the seventh capacitor C7 and the eighth capacitor C8 and each pin in the rectifier controller 107 can be seen in Figure 1 As shown, no further description is given here.

[0108] The rectifier controller 107 in this embodiment may be a synchronous rectifier controller, which is a key control element in a switching power supply system and can optimize the rectification process in the power supply circuit and replace the traditional diode rectifier.

[0109] In some embodiments, see Figure 1As shown, the adapter power circuit further includes a fifth capacitor C5 , which is connected in parallel at both ends of the light receiver 103 to protect the light receiver 103 .

[0110] In some embodiments, see Figure 1 As shown, the adapter power circuit also includes a fifth resistor R5, a first end of the fifth resistor R5 is connected to the opposite end of the secondary winding L2, and a second end of the fifth resistor R5 is the output negative terminal. In other words, the fifth resistor R5 is connected in series in the output loop of the circuit for real-time detection of the load.

[0111] In some embodiments, see Figure 1 As shown, the adapter power circuit also includes a seventh resistor R7, a first end of the seventh resistor R7 is connected to the output end of the rectifier controller 107, and a second end of the seventh resistor R7 is connected to the positive electrode of the light source 106 in the optocoupler. The seventh resistor R7 plays a role of current limiting in the path of the light source 106 to prevent the light source 106 from being damaged by excessive current in the path.

[0112] Please continue to see Figure 1 As shown, the rectifier circuit 102 of this embodiment can adopt a bridge rectifier circuit composed of four diodes, and the bridge rectifier circuit converts the AC power output by the AC transformer circuit into a unidirectional pulsating DC signal.

[0113] It can be seen that by adopting the adapter power supply circuit provided in this embodiment, when an abnormal situation occurs in the circuit, there is no need to increase or decrease the charging voltage output by the circuit, so that the primary circuit triggers the overvoltage protection mechanism or the undervoltage protection mechanism, which will not cause frequent high-voltage shocks to the components in the circuit, thereby ensuring the working life of the circuit; in addition, the circuit of this embodiment will not be falsely triggered due to dynamic jumps of the load when the charging voltage is low, thereby ensuring the stability of the circuit operation.

[0114] It can be understood that, in this embodiment, the above-mentioned various detection processes are only performed after the entire circuit system works normally, and are not performed during the circuit startup process.

[0115] It is understandable that the above embodiments are only Figure 1 The USB-A circuit structure shown in the figure is used as an example to illustrate the technical solution of the present application, but it does not mean that the technical solution provided by the present application can only be applied to the following examples: Figure 1 In the USB-A circuit structure shown, in other embodiments, the technical solution concept of the present application can also be applied to USB-A circuits or USB-C circuits in other circuit structures.

[0116] In addition, based on the adapter power circuit provided in the above embodiment, an embodiment of the present application further provides a power adapter, which includes the adapter power circuit as described above.

[0117] Finally, it should be noted that the above embodiments are only specific implementation methods of the present application, but the protection scope of the present application is not limited thereto, and any changes or substitutions within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. An electronic equipment adapter power circuit, characterized in that: include: A rectifier circuit, a first transistor, a transformer, an optocoupler, a primary side controller, a rectifier controller and a protocol controller; Wherein, the input end of the rectifier circuit is used to connect to the first power supply; the output end of the rectifier circuit is connected to the input end of the primary winding loop of the transformer; the control signal output pin of the primary controller is connected to the control electrode of the first transistor, the first electrode of the first transistor is connected to the same-name end of the primary winding of the transformer, and the second electrode of the first transistor is grounded; the feedback signal collection pin of the primary controller is connected to the first end of the photoreceiver of the optocoupler, and the second end of the photoreceiver of the optocoupler is grounded; The rectifier controller is connected in series in the secondary winding loop of the transformer, and the output end of the secondary winding loop is the charging output end of the adapter power circuit; the optocoupler drive pin of the protocol controller is connected to the negative electrode of the light source of the optocoupler, and the positive electrode of the light source of the optocoupler is connected to the positive electrode of the charging output end; the detection pin of the protocol controller is connected to the charging output end; the communication protocol signal pin of the protocol controller is the fast charging protocol signal terminal of the adapter power circuit; The protocol controller is used to determine whether there is an abnormality in the current state according to the detection signal collected by the detection pin. If so, the protocol controller controls to increase the current value of the path where the light source of the optical coupler is located, so that the current value of the path where the light receiver is located increases, thereby lowering the voltage value of the feedback signal on the feedback signal pin; The primary side controller is used to control the first transistor to turn off when it is detected that the voltage value of the feedback signal on the feedback signal pin is pulled down to zero, so that the voltage value of the charging output terminal is reduced; The protocol controller is further used to detect whether the voltage value of the charging output terminal drops to a first voltage threshold value during the process of the voltage value of the charging output terminal decreasing, and if so, control to reduce the current value of the path where the light source is located, so that the current value of the path where the light receiver is located is reduced, thereby increasing the voltage value of the feedback signal on the feedback signal pin; The primary side controller is also used to detect whether the voltage value of the feedback signal on the feedback signal pin increases to a second voltage threshold during the increase of the voltage value of the feedback signal. If so, control the first transistor to be turned off or control the turn-off or conduction frequency of the first transistor.

2. The electronic device adapter power supply circuit according to claim 1, characterized in that: The primary side controller comprises a zero-crossing detection circuit and a zero-crossing detection pin, and the zero-crossing detection circuit is connected to the zero-crossing detection pin; The adapter power supply circuit also includes a power taking winding, which is coupled to the secondary winding of the transformer; a first end of the power taking winding is grounded, and a second end of the power taking winding is connected to the zero crossing detection pin; The zero-crossing detection circuit is used to detect the voltage value of the second end of the power-taking winding; The primary side controller is also used to detect whether the voltage value at the second end of the power taking winding drops to a third voltage threshold value during the process of reducing the current value in the path where the light receiver is located. If so, control the feedback signal pin to be turned on to collect the voltage value of the feedback signal.

3. The electronic device adapter power supply circuit according to claim 1 or 2, characterized in that: The adapter power circuit includes a first capacitor and a first resistor; the protocol controller includes a first differential signal pin and a second differential signal pin; The first differential signal pin is connected to the first end of the first resistor, the second end of the first resistor is connected to the negative electrode of the charging output terminal, the first differential signal pin is also connected to the first end of the first capacitor, and the second end of the first capacitor is grounded; the second differential signal pin is grounded; The first differential signal pin and the second differential signal pin are used to sample the current value on the charging output end; The protocol controller is further used to determine whether the current value on the charging output end is greater than a first current threshold or less than a second current threshold. If so, it is determined that an abnormality exists in the current state.

4. The electronic device adapter power supply circuit according to claim 1 or 2, characterized in that: The protocol controller includes a voltage sampling pin, and the voltage sampling pin is connected to the positive electrode of the charging output terminal; The protocol controller is further used to collect the voltage value of the charging output terminal through the voltage sampling pin; The protocol controller is further used to determine whether the voltage value of the charging output terminal is greater than a fourth voltage threshold or less than a fifth voltage threshold. If so, it is determined that an abnormality exists in the current state.

5. The electronic device adapter power supply circuit according to claim 1 or 2, characterized in that: The adapter power circuit includes a second resistor; The protocol controller comprises a temperature sampling pin, the temperature sampling pin is connected to the first end of the second resistor, and the second end of the second resistor is grounded; The protocol controller is used to collect the temperature value in the current environment through the temperature sampling pin, and determine whether the temperature value is greater than a first temperature threshold or less than a second temperature threshold. If so, it is determined that there is an abnormality in the current state.

6. The electronic device adapter power supply circuit according to claim 1 or 2, characterized in that: The adapter power supply circuit also includes an RCD absorption circuit; The input end of the RCD absorption circuit is connected to the same-name end of the primary winding of the transformer, and the output end of the RCD absorption circuit is connected to the opposite-name end of the primary winding; the RCD absorption circuit and the primary winding form the primary winding loop.

7. The electronic device adapter power supply circuit according to claim 1 or 2, characterized in that: The adapter power circuit also includes a second capacitor and a third capacitor; The first output end of the rectifier circuit is connected to the first end of the second capacitor, and the second output end of the rectifier circuit is connected to the second end of the second capacitor; the first output end of the rectifier circuit is also connected to the opposite end of the primary winding; The same-name end of the secondary winding is connected to the input end of the rectifier controller, the output end of the rectifier controller is connected to the first end of the third capacitor, and the second end of the third capacitor is connected to the opposite-name end of the secondary winding.

8. The electronic device adapter power supply circuit according to claim 2, characterized in that: The adapter power supply circuit further includes a first voltage dividing circuit, wherein the first voltage dividing circuit includes at least two voltage dividing resistors; The first end of the first voltage divider circuit is connected to the second end of the power taking winding, the second end of the first voltage divider circuit is grounded, and the voltage output end of the first voltage divider circuit is connected to the zero crossing detection pin.

9. A power adapter, characterized in that: The adapter comprises a power supply circuit as claimed in any one of claims 1 to 8.

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