A control method of a power adapter, the power adapter and an electronic device

Abstract

The application discloses a control method of a power adapter, the power adapter and electronic equipment. The control method comprises the following steps: in response to the first trigger condition being met, an output voltage is adjusted to a first voltage by a secondary side controller of the power adapter, the first voltage is a target low voltage capable of maintaining the operation of the secondary side controller; a reference voltage is generated by a primary side controller of the power adapter based on a primary side voltage corresponding to the first voltage; after the primary side controller enters a primary side adjustment mode based on the reference voltage, a feedback path used for providing a feedback signal to the primary side controller is used to enter a low-power consumption state by the secondary side controller.

Description

Technical Field

[0001] This application relates to the technical field of power adapters, and particularly to a control method for a power adapter, a power adapter, and an electronic device. Background Technology

[0002] Currently, power adapters use transformers to convert the input AC power into the voltage required by the device to be charged, thus achieving the purpose of charging the device. In one related scheme, when the device does not need charging (e.g., the device's battery is fully charged) or the power adapter is not connected to the device, the secondary-side controller sends a specific coded signal to the primary-side controller to put the primary side into standby mode, and the secondary-side controller maintains low-power operation of the power adapter according to a preset fixed voltage.

[0003] To compensate for output voltage deviations caused by variations in transformer winding and switching parameters, and to prevent undervoltage lockout triggered by the secondary controller, some solutions set the standby output voltage to a fixed voltage with a large margin to ensure stable operation of the secondary controller. This results in relatively high power consumption of the power adapter even in standby mode. Furthermore, the primary controller requires additional decoding circuitry to parse specific encoded signals, increasing the circuit complexity and manufacturing cost of the power adapter. In addition, in some standby control schemes, the feedback path between the primary and secondary sides still needs to continuously transmit feedback signals, and the quiescent current of the feedback path also increases the standby power consumption of the power adapter. Summary of the Invention

[0004] This application provides a control method for a power adapter, a power adapter, and an electronic device.

[0005] In a first aspect, embodiments of this application provide a control method for a power adapter, including: In response to the fulfillment of a first trigger condition, the output voltage is adjusted to a first voltage via the secondary-side controller of the power adapter. The first voltage is a target low voltage that can sustain the operation of the secondary-side controller. A reference voltage is generated based on the primary-side voltage corresponding to the first voltage through the primary-side controller of the power adapter; After the primary-side controller enters the primary-side regulation mode based on the reference voltage, it enters a low-power state through the feedback path used by the secondary-side controller to provide feedback signals to the primary-side controller.

[0006] In one possible implementation, The first voltage is determined based on the undervoltage lockout shutdown threshold range of the secondary-side controller; The first voltage is greater than or equal to the upper limit of the undervoltage lockout threshold range, and the voltage difference between the first voltage and the upper limit is less than or equal to a preset voltage margin.

[0007] In one possible implementation, generating a reference voltage based on the primary-side voltage corresponding to the first voltage includes: The auxiliary winding voltage of the transformer of the power adapter is sampled by the primary side controller to obtain multiple auxiliary winding voltage sample values, and the auxiliary winding voltage has a corresponding relationship with the output voltage. If the auxiliary winding voltage meets the preset stability condition and continues for a first duration, the multiple auxiliary winding voltage sampling values ​​collected within the first duration are processed according to the preset processing method to obtain the reference voltage. The preset processing method includes average value calculation and / or digital filtering.

[0008] In one possible implementation, the primary-side controller enters a primary-side regulation mode based on the reference voltage, including: The primary-side controller adjusts the switching control parameters of the main power switch of the primary-side circuit based on the comparison result between the auxiliary winding voltage and the reference voltage, so as to change the energy transmitted to the secondary side via the transformer and maintain the output voltage within the voltage range corresponding to the first voltage. Stop responding to the feedback signals provided by the feedback path; Specifically, when the auxiliary winding voltage is less than the reference voltage, the energy transmitted to the secondary side via the transformer is increased; When the auxiliary winding voltage is greater than the reference voltage, the energy transmitted to the secondary side via the transformer is reduced.

[0009] In one possible implementation, entering a low-power state via a feedback path used by the secondary-side controller to provide a feedback signal to the primary-side controller includes: When the output voltage is maintained within the voltage range corresponding to the first voltage for a duration of a second duration, the system enters a low-power state through the feedback path used by the secondary-side controller to provide a feedback signal to the primary-side controller; wherein the second duration is longer than the first duration. The process of putting the feedback path into a low-power state includes at least one of the following: Disconnect the feedback path; Reduce the current in the feedback path; Stop the feedback path from providing feedback signals for secondary-side adjustment to the primary-side controller; The feedback path is controlled to retain the wake-up detection function or the state retention function; This enables other isolated feedback paths to enter a low-power or non-feedback operating state.

[0010] In one possible implementation, the control method further includes: In response to the fulfillment of the second triggering condition, the secondary-side controller switches the feedback path from the low-power state to the working state, so that the feedback path provides a feedback signal to the primary-side controller. The primary-side controller detects the voltage change at the feedback detection terminal connected to the feedback path due to the state switching of the feedback path; When the voltage change meets the wake-up condition, the primary-side controller exits the primary-side regulation mode and enters the secondary-side regulation mode. The wake-up condition includes one of the following: The voltage at the feedback detection terminal generates a falling edge; The voltage at the feedback detection terminal is less than the preset wake-up voltage; The duration for which the voltage at the feedback detection terminal is less than the preset wake-up voltage reaches the preset wake-up duration.

[0011] In one possible implementation, the control method further includes: After the primary-side controller enters the secondary-side adjustment mode, the secondary-side controller adjusts the output voltage from the first voltage to the second voltage. The second voltage is the output voltage of the power adapter in normal power supply mode, and the second voltage is greater than the first voltage.

[0012] In one possible implementation, The first triggering condition includes one of the following: An external electronic device was detected to be disconnected from the output of the power adapter. The voltage state of the configuration channel of the power adapter is detected to meet the preset low standby conditions; A low standby command is received through the configuration channel of the power adapter; The second triggering condition includes one of the following: An external electronic device was detected connected to the output terminal of the power adapter. The voltage state of the configuration channel of the power adapter is detected to meet the preset wake-up conditions; The wake-up command is received through the configuration channel of the power adapter.

[0013] Secondly, this application also provides a power adapter, including a primary side circuit, a secondary side circuit, and a feedback path disposed between the primary side circuit and the secondary side circuit. The primary side circuit includes a primary side controller, the secondary side circuit includes a secondary side controller, and the feedback path is used to transmit a feedback signal provided by the secondary side controller to the primary side controller. The secondary-side controller is used to adjust the output voltage to a first voltage in response to the fulfillment of a first trigger condition, wherein the first voltage is a target low voltage that can maintain the operation of the secondary-side controller; The primary-side controller is used to generate a reference voltage based on the primary-side voltage corresponding to the first voltage, and to enter the primary-side regulation mode based on the reference voltage; The secondary-side controller is also used to control the feedback path to enter a low-power state after the primary-side controller enters the primary-side adjustment mode.

[0014] Thirdly, embodiments of this application also provide an electronic device, including: The device body includes a load circuit; A power adapter disposed on or connected to the device body and used to supply power to the load circuit; The power adapter includes a primary side circuit, a secondary side circuit, and a feedback path disposed between the primary side circuit and the secondary side circuit. The primary side circuit includes a primary side controller, the secondary side circuit includes a secondary side controller, and the feedback path is used to transmit the feedback signal provided by the secondary side controller to the primary side controller. The secondary-side controller is used to adjust the output voltage to a first voltage in response to the fulfillment of a first trigger condition, wherein the first voltage is a target low voltage that can maintain the operation of the secondary-side controller; The primary-side controller is used to generate a reference voltage based on the primary-side voltage corresponding to the first voltage, and to enter the primary-side regulation mode based on the reference voltage; The secondary-side controller is also used to control the feedback path to enter a low-power state after the primary-side controller enters the primary-side adjustment mode. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1A circuit diagram of a power adapter provided in this application is shown; Figure 2 A flowchart of a control method for a power adapter provided in this application is shown; Figure 3 This application provides a flowchart of a method for generating a reference voltage based on a primary side voltage corresponding to a first voltage. Figure 4 A flowchart of another power adapter control method provided in this application is shown; Figure 5 A flowchart illustrating an example of a power adapter entering a low standby mode provided in this application is shown. Figure 6 A flowchart illustrating an example of a power adapter exiting low standby mode provided in this application is shown. Figure 7 This application provides a timing diagram. Figure 8 A schematic diagram of the structure of an electronic device provided in this application is shown. Detailed Implementation

[0017] Various embodiments and features of this application are described herein with reference to the accompanying drawings.

[0018] It should be understood that various modifications can be made to the embodiments described herein. Therefore, the above description should not be considered as limiting, but merely as an example of embodiments. Other modifications within the scope and spirit of this application will be apparent to those skilled in the art.

[0019] The accompanying drawings, which are included in and form part of this specification, illustrate embodiments of the present application and, together with the general description of the present application given above and the detailed description of the embodiments given below, serve to explain the principles of the present application.

[0020] These and other features of this application will become apparent from the following description of preferred forms of embodiments given as non-limiting examples, with reference to the accompanying drawings.

[0021] It should also be understood that although this application has been described with reference to some specific examples, those skilled in the art can certainly implement many other equivalent forms of this application, which have the features described in the claims and are therefore all within the scope of protection defined herein.

[0022] The above and other aspects, features and advantages of this application will become more apparent when taken in conjunction with the accompanying drawings and in view of the following detailed description.

[0023] Specific embodiments of this application are described thereafter with reference to the accompanying drawings; however, it should be understood that the claimed embodiments are merely examples of this application, which can be implemented in various ways. Well-known and / or repeated functions and structures are not described in detail to avoid unnecessary or redundant details that could obscure the application. Therefore, the specific structural and functional details claimed herein are not intended to be limiting, but merely serve as the basis and representative basis for the claims to teach those skilled in the art to use this application in a variety of substantially any suitable detailed structures.

[0024] This specification may use the phrases “in one embodiment,” “in another embodiment,” “in yet another embodiment,” or “in other embodiments,” all of which may refer to one or more of the same or different embodiments according to this application.

[0025] On the one hand, the embodiments of this application combine Figure 1 The circuit diagram of the power adapter shown provides a detailed explanation of the power adapter's control method. (Refer to...) Figure 1 It is known that the power adapter includes a primary side circuit, a secondary side circuit, a feedback path and transformer between the primary side circuit and the secondary side circuit, a main power switch in the primary side circuit, a blocking switch in the secondary side circuit, an AC-DC converter, a rectifier, and several resistors, etc. Furthermore, the primary side circuit includes a primary side controller (1... st Controller), the secondary circuit includes the secondary controller (2 nd The feedback path (controller) is used to transmit the feedback signal provided by the secondary controller to the primary controller. This feedback path includes LEDs and phototransistors. It should be noted that... Figure 1 This is for illustrative purposes only; the actual circuit diagram is not limited to this.

[0026] As an example, Figure 2 A flowchart of a power adapter control method provided in an embodiment of this application is shown, wherein the steps specifically include S201-S203.

[0027] S201, in response to the fulfillment of the first trigger condition, the output voltage is adjusted to a first voltage by the secondary side controller of the power adapter. The first voltage is a target low voltage that can maintain the operation of the secondary side controller.

[0028] The first trigger condition in this embodiment is used to instruct the power adapter to switch to a low standby mode. Optionally, the first trigger condition may include detecting that the external electronic device is disconnected from the output terminal of the power adapter, that is, the power adapter does not need to transfer power to the external electronic device. At this time, the power adapter can be instructed to switch to a low standby mode. Specifically, the voltage of the configuration channel pin is monitored by the secondary-side controller of the power adapter. If the voltage of the configuration channel pin falls within a first preset range, such as 3.3 ± 0.2V, it indicates that the external electronic device is disconnected from the output terminal of the power adapter; if the voltage of the configuration channel pin falls within a second preset range, such as 0.8 ± 0.2V, it indicates that the external electronic device is connected to the output terminal of the power adapter. That is, when the voltage of the configuration channel pin is detected to fall within the first preset range, it is determined that the first trigger condition is met.

[0029] In another example, the first trigger condition may also include detecting that the voltage state of the configuration channel of the power adapter meets a preset low standby condition. The preset low standby condition may include the voltage state of the configuration channel representing that the voltage of the configuration channel pin rises from falling into a second preset range to falling into a first preset range within a preset time period. That is, if the voltage of the configuration channel pin rises from falling into the second preset range to falling into the first preset range within a preset time period, it is determined that the first trigger condition is met.

[0030] As another example, the first triggering condition may also include receiving a low standby command through the power adapter's configuration channel; that is, if a low standby command is received, it is determined that the first triggering condition is met. The low standby command can be generated in the following scenarios: for example, when an external electronic device is connected to the power adapter, the external electronic device generates a corresponding low standby command based on a user-executed stop-charging operation and transmits it to the power adapter through the configuration channel, causing the power adapter to switch to low standby mode and stop transmitting power to the external electronic device; or, again, when an external electronic device is connected to the power adapter, the external electronic device reaches its maximum stable operating temperature, at which point the external electronic device generates a low standby command and transmits it to the power adapter, etc.

[0031] Upon receiving a low standby command, the secondary controller blocks the second trigger condition generated by the connection status during the validity period of the low standby command; after the low standby command is revoked or a wake-up command is received, the connection status detection is resumed.

[0032] In this embodiment of the application, in response to the fulfillment of the first triggering condition, the output voltage is adjusted to a first voltage by the secondary side controller of the power adapter. The first voltage is a target low voltage that can maintain the operation of the secondary side controller. The target low voltage can be the minimum voltage that can maintain the operation of the secondary side controller, or it can be a voltage that is greater than the minimum voltage and the difference between the minimum voltage and the minimum voltage is within a preset range.

[0033] The first voltage is determined based on the undervoltage lockout threshold range of the secondary controller. The first voltage is greater than or equal to the upper limit of the undervoltage lockout threshold range, and the voltage difference between the first voltage and the upper limit is less than or equal to a preset voltage margin. For example, the undervoltage lockout threshold range of the secondary controller is 2V-2.9V, where 2.9V represents the highest shutdown threshold value that ensures normal operation of the secondary controller under the worst ambient temperature and process variations. Therefore, setting the first voltage to be greater than or equal to the upper limit of the undervoltage lockout threshold range, such as 3V, ensures that the secondary controller can maintain its basic functions stably without being affected by undervoltage lockout protection. It should be noted that different controllers have different undervoltage lockout threshold ranges, and the undervoltage lockout threshold range for each controller can be obtained from its attribute information. Furthermore, it is preferable to set a voltage difference between the first voltage and the upper limit of the undervoltage lockout threshold range. This voltage difference is used to buffer voltage fluctuations caused by various devices in the circuit, preventing undervoltage lockout shutdown due to voltage fluctuations.

[0034] Meanwhile, to avoid wasted or excessive power consumption, the voltage difference between the first voltage and the upper limit is limited to less than or equal to a preset voltage margin, such as 0.1V, so as to ensure that the secondary controller can operate stably while maintaining low power consumption.

[0035] S202 generates a reference voltage based on the primary side voltage corresponding to the first voltage through the primary side controller of the power adapter.

[0036] Reference Figure 1 As can be seen, in the power adapter of this application embodiment, its transformer includes a primary winding N. p Secondary winding N s and auxiliary winding N aux Primary winding N p Connect to the high-voltage busbar to connect to the mains power, secondary winding N s Connect the output terminal to supply power to external electronic devices; auxiliary winding N aux Grounding is used as the basis for control of the primary side controller.

[0037] As can be seen from the working principle of transformer windings, the primary side voltage and secondary side voltage are in a certain ratio depending on the transformer windings. After the secondary side controller adjusts the output voltage to the first voltage, the primary side voltage, including the auxiliary winding voltage, decreases proportionally according to the turns ratio of the auxiliary winding. It should be noted that the primary side voltage can also include the mains input voltage, the primary winding voltage, etc. The number of turns in the secondary winding, the number of turns in the auxiliary winding, and the output voltage V... o and auxiliary winding voltage V aux Satisfy the following formula: V aux =(Naux / N s )×V o .

[0038] The response output voltage is adjusted to the first voltage, and the auxiliary winding voltage is sampled via the primary side controller of the power adapter. The sampling frequency and number of samples can be preset. After obtaining multiple auxiliary winding voltages, a reference voltage is further determined.

[0039] Of course, it is also possible to configure the primary-side controller to continuously sample the auxiliary winding voltage before and after the response output voltage is adjusted to the first voltage; alternatively, it is possible to configure the primary-side controller to sample the auxiliary winding voltage at a first sampling frequency and a first number of samples before the response output voltage is adjusted to the first voltage, and to sample the auxiliary winding voltage at a second sampling frequency and a second number of samples after the response output voltage is adjusted to the first voltage. This application does not limit this specific configuration.

[0040] S203, after the primary-side controller enters the primary-side regulation mode based on the reference voltage, it enters the low-power state through the feedback path used by the secondary-side controller to provide feedback signals to the primary-side controller.

[0041] After generating the reference voltage, it can be stored in an internal buffer, register, non-volatile memory cell, or sample-and-hold circuit, etc., for the primary-side controller to read and use to control it to enter the primary-side regulation mode. In this primary-side regulation mode, the primary-side controller controls the switching control parameters of the main power switch of the primary-side circuit according to the reference voltage. These switching control parameters include at least one of the following: on-time, on / off frequency, on / off period, duty cycle, and energy transferred per on / off period.

[0042] For example, when the primary side controller enters the primary side regulation mode based on the reference voltage, it can still sample the auxiliary winding voltage and compare the auxiliary winding voltage with the reference voltage. Based on the comparison result between the auxiliary winding voltage and the reference voltage, the primary side controller adjusts the switching control parameters of the main power switch of the primary side circuit to change the energy transmitted to the secondary side via the transformer, so that the output voltage is maintained within the voltage range corresponding to the first voltage.

[0043] Specifically, the primary-side controller includes a PWM comparator, which controls the reduction of the on-time and off-time of the main power switch by comparing two inputs (in this embodiment, the two inputs are that the auxiliary winding voltage is less than the reference voltage), thereby achieving the purpose of increasing the switching frequency, increasing the switching period, or decreasing the duty cycle. If the auxiliary winding voltage is less than the reference voltage, the primary-side controller controls the increase of the switching frequency of the main power switch, decreases the switching period, or increases the duty cycle, etc., to increase the energy transmitted to the secondary side through the transformer. That is, increasing the switching frequency of the main power switch, decreasing the switching period, or increasing the duty cycle, etc., increases the current in the primary-side circuit, increases the magnetic energy stored in the transformer core, and correspondingly, the secondary-side circuit obtains more energy, and the output voltage increases to fall into the voltage range corresponding to the first voltage. If the auxiliary winding voltage is greater than the reference voltage, the primary-side controller controls the decrease of the switching frequency of the main power switch, increases the switching period, or decreases the duty cycle, etc., to decrease the energy transmitted to the secondary side through the transformer. The specific process is the reverse of the above-mentioned increase process, and will not be described in detail here. Therefore, the output voltage of the power adapter can be maintained within the voltage range corresponding to the first voltage. The voltage range corresponding to the first voltage results in lower power consumption of the power adapter. Considering that the higher the switching frequency, switching period and duty cycle are, the higher the power consumption of the main power switch is, it is preferable to maintain the output voltage of the power adapter at or below the median value of the voltage range corresponding to the first voltage.

[0044] Furthermore, when the primary side controller enters the primary side adjustment mode, the primary side controller stops responding to the feedback signals provided by the feedback path. That is, even if it receives the feedback signals provided by the feedback path, it will no longer respond to the feedback signals.

[0045] Correspondingly, after the primary-side controller enters the primary-side regulation mode based on the reference voltage, the feedback path used by the secondary-side controller to provide feedback signals to the primary-side controller enters a low-power state. Considering that if the secondary-side controller controls the feedback path to enter a low-power state before the primary-side controller enters the primary-side regulation mode, it would prevent the auxiliary winding voltage from being sampled, thus failing to obtain the reference voltage or an accurate reference voltage, this embodiment of the application, when the feedback path used by the secondary-side controller to provide feedback signals to the primary-side controller enters a low-power state, first determines whether the duration for which the output voltage is maintained within the voltage range corresponding to the first voltage reaches a second duration. If it does, the secondary-side controller enables the feedback path to enter a low-power state; if not, the secondary-side controller does not perform the operation of enabling the feedback path to enter a low-power state. It should be noted that the second duration can also be the duration for which the auxiliary winding voltage meets a preset stability condition and remains stable.

[0046] The second duration is longer than the first duration. In other words, the secondary controller only performs the operation of putting the feedback path into a low-power state after the primary controller enters the primary regulation mode, so as to obtain an accurate reference voltage and thus ensure the control basis of the primary controller, avoiding the output voltage from drifting, instability or overvoltage.

[0047] Optionally, putting the feedback path into a low-power state may include disconnecting the feedback path, such as stopping the current transmission to the feedback path; putting the feedback path into a low-power state may also include reducing the current in the feedback path, i.e., reducing the current transmitted to the feedback path; putting the feedback path into a low-power state may also include stopping the feedback path from providing feedback signals to the primary-side controller for secondary-side regulation, i.e., controlling the LED to remain off or maintain a constant brightness (low brightness); putting the feedback path into a low-power state may also include controlling the feedback path to retain the wake-up detection function or state holding function, so as to respond to the wake-up command in a timely manner and switch from the low-power state to the operating state. For example, retaining the wake-up detection function includes continuously monitoring the voltage change at the feedback detection terminal, and responding to the voltage change in a timely manner to switch the operating mode, or, if the voltage does not change or the voltage change is within a certain range, maintaining the current operating mode is sufficient.

[0048] Furthermore, other isolated feedback paths can be included between the primary and secondary circuits. Therefore, putting the feedback path into a low-power state can also include putting other isolated feedback paths into a low-power or non-feedback operating state. This achieves the goal of reducing the operating power consumption of the feedback path.

[0049] The power adapter may also include one or more of magnetic isolation, capacitive isolation, and digital isolators. When entering a low-power state, since neither the primary nor secondary circuits need to communicate, the capacitive isolation or digital isolators used for signal transmission can be disconnected. However, since the primary and secondary circuits still need to transfer energy, the magnetic isolation remains active. The low-power state includes directly disconnecting the feedback path. The non-feedback operating state is a state where no response or signal transmission occurs. Compared to the low-power state, this still incurs some power consumption; therefore, it is preferable to control the system to enter a low-power state.

[0050] Simultaneously, some components can be shut down or disconnected via the secondary-side controller (components that do not affect the secondary-side controller's ability to receive and respond to wake-up commands). Correspondingly, some components can also be shut down or disconnected via the primary-side controller, thereby reducing the overall power consumption of the power adapter.

[0051] In this embodiment, when the first trigger condition is met—that is, the power adapter is instructed to switch to primary-side regulation mode—the secondary-side controller actively adjusts the output voltage to a first voltage sufficient to maintain its operation. Subsequent mode switching is then performed based on this voltage, ensuring the secondary-side controller operates with low power consumption. At this time, the power adapter has a configuration channel pin detection function to respond to wake-up commands (such as voltage changes or digital communication signals) for mode switching. It also has overvoltage protection to prevent damage to the power adapter caused by abnormally high output voltage due to transformer or feedback loop failure, external surges or lightning strikes, or component aging.

[0052] Furthermore, the primary side voltage sampled in real time in this embodiment of the application involves the actual impact of components such as transformer windings and switches. A reference voltage is then generated based on the primary side voltage, and the system enters a primary side regulation mode according to the reference voltage. That is, the output voltage of the power adapter is stabilized at or around a first voltage based on the reference voltage, effectively and accurately determining the voltage margin caused by components such as transformer windings and switches, and automatically achieving error compensation. Compared to related technologies that set a large fixed voltage to ensure the stable operation of the secondary side controller, this embodiment of the application not only ensures the stable operation of the secondary side controller but also ensures low power consumption of the power adapter, improving energy efficiency.

[0053] Furthermore, in this embodiment, the secondary-side controller does not need to send a specific encoded signal to the primary-side controller. By adjusting the output voltage, the primary-side controller can enter the primary-side regulation mode, which means that the power adapter can enter the low standby mode. This avoids the problems of high circuit complexity and high manufacturing cost caused by adding an additional decryption circuit to the primary-side controller. It greatly simplifies the control logic and reduces the manufacturing cost. At the same time, it reduces the size of the primary-side controller and meets the requirements of lightweight design.

[0054] For example, Figure 3 A flowchart of a method for generating a reference voltage based on a primary side voltage corresponding to a first voltage, provided in an embodiment of this application, is shown, wherein the steps specifically include S301 and S302.

[0055] S301 samples the auxiliary winding voltage of the transformer of the power adapter through the primary side controller, and obtains multiple auxiliary winding voltage sampling values. The auxiliary winding voltage and the output voltage have a corresponding relationship.

[0056] S302, when the auxiliary winding voltage meets the preset stability condition and continues for a first duration, the multiple auxiliary winding voltage sampling values ​​collected within the first duration are processed according to the preset processing method to obtain the reference voltage.

[0057] After the secondary-side controller adjusts the output voltage to the first voltage, the auxiliary winding voltage changes proportionally with the output voltage. At this time, the primary-side controller samples the auxiliary winding voltage of the power adapter's transformer, obtaining multiple auxiliary winding voltage sample values. Correspondingly, the auxiliary winding voltage and the output voltage have a corresponding relationship, namely V... aux =(N aux / N s )×V o Of course, in actual circuits, considering that other components such as the main power switch and windings will generate voltage drops that cause certain losses, the above correspondence can also be expressed as V. aux =(N aux / N s )×V o -V 其他 V 其他 This refers to the voltage drop generated by other devices.

[0058] If the auxiliary winding voltage meets the preset stability condition and remains stable for a first duration, the multiple auxiliary winding voltage sample values ​​collected within the first duration are processed according to a preset processing method to obtain a reference voltage. The preset processing method includes average value calculation and / or digital filtering. Digital filtering may include moving average, median filtering, low-pass filtering, weighted filtering, and setting of filtering windows or coefficients. In specific implementations, after each sampling of the auxiliary winding voltage sample value, the sample value can be stored in an internal buffer or sample-and-hold circuit according to the sampling time for subsequent processing according to the preset processing method.

[0059] The preset stability conditions may include the auxiliary winding voltage being less than a threshold voltage, where the threshold voltage is the minimum voltage at which the primary-side controller enters the primary-side regulation mode. This threshold voltage can be the minimum voltage that the primary-side controller can maintain operation at, or a voltage greater than this minimum voltage, such as 10V. The preset stability conditions may also include the difference between sampled adjacent auxiliary winding voltages being less than a first threshold. Furthermore, the preset stability conditions may include the voltage fluctuation amplitude of the sampled auxiliary winding voltage within a first time period being less than a second threshold. Considering that the auxiliary winding voltage being less than the threshold voltage may be caused by instantaneous voltage fluctuations or a sudden increase in voltage drop caused by a certain device, when the auxiliary winding voltage is less than the threshold voltage, it is further determined that the difference between adjacent auxiliary winding voltages is less than the first threshold to further confirm that the auxiliary winding voltage meets the preset stability conditions and prevent malfunction of the primary-side controller.

[0060] It should be noted that both the primary-side controller and the secondary-side controller in this application embodiment may include a timing module, a control module, a comparison module, etc., to realize functions such as timing control and comparison control. The specific models and configuration parameters of each module are not described in detail here.

[0061] This embodiment of the application samples the primary-side voltage corresponding to the first voltage using a primary-side controller to generate a reference voltage as the basis for subsequent control. This achieves automatic compensation for deviations caused by the transformer windings and other components, thereby ensuring low overall power consumption and stable operation when the power adapter is controlled according to the reference voltage. Furthermore, it is applicable to different transformers (with different winding turns ratios) and / or other components with different properties, thus having a wide range of applications. The reference voltage is generated when the auxiliary winding voltage meets a preset stability condition for a sustained period of time. This eliminates errors caused by the instantaneous preset stability condition of the auxiliary winding voltage and defines preset processing methods, such as suppressing random noise through averaging calculation and suppressing switching ripple, abnormal sampling values, or high-frequency interference through digital filtering, ensuring the accuracy of the reference voltage. It is worth noting that averaging calculation and digital filtering can be used simultaneously, that is, the voltage value obtained by averaging calculation and the voltage value obtained by digital filtering are then averaged to obtain the reference voltage, which is more accurate than averaging calculation and digital filtering alone.

[0062] For example, Figure 4 A flowchart of another power adapter control method provided in an embodiment of this application is shown, wherein the steps specifically include S401-S403.

[0063] S401, in response to the fulfillment of the second trigger condition, switches the feedback path from a low-power state to an operating state through the secondary-side controller, so that the feedback path provides a feedback signal to the primary-side controller.

[0064] S402 detects voltage changes at the feedback detection terminal connected to the feedback path due to state switching of the feedback path via the primary side controller.

[0065] S403, when the voltage change meets the wake-up condition, exits the primary side regulation mode and enters the secondary side regulation mode through the primary side controller.

[0066] The second trigger condition in this embodiment is used to indicate that the power adapter is out of low standby mode. Optionally, the second trigger condition may include detecting that an external electronic device is connected to the output terminal of the power adapter. For example, it may be determined whether an external electronic device is connected to the output terminal by the voltage of the configuration channel pin. That is, when the voltage of the configuration channel pin is detected to fall within a second preset range, it is determined that the second trigger condition is met.

[0067] In another example, the second triggering condition may further include detecting that the voltage state of the configuration channel of the power adapter meets a preset wake-up condition. The voltage state of the configuration channel can be determined by the voltages of multiple configuration channel pins over a period of time. The preset wake-up condition may include the voltage state of the configuration channel representing a decrease in the voltage of the configuration channel pin from falling within a first preset range to falling within a second preset range within a preset time period. That is, if the voltage of the configuration channel pin decreases from falling within the first preset range to falling within the second preset range within the preset time period, the second triggering condition is determined to be met. Here, determining whether the preset wake-up condition is met through voltage changes within a preset time period can effectively reduce false triggering caused by voltage fluctuations.

[0068] As another example, the second triggering condition may also include receiving a wake-up command through the configuration channel of the power adapter; that is, if the received wake-up command determines that the second triggering condition is met. The wake-up command can be generated in the following scenarios: for example, when the power adapter is connected to an external electronic device and the power adapter is in a low standby mode due to the high temperature of the external electronic device, a wake-up command can be generated and transmitted to the power adapter once the temperature of the external electronic device drops to a level where it can operate normally.

[0069] This application embodiment triggers whether to exit the low standby mode based on a second trigger condition. Automatic triggering and mode switching can be achieved without upper-level instructions. At the same time, no additional hardware or other new detection circuits are required. It can be achieved through the reused configuration channel pins. Furthermore, it is suitable for scenarios where the power adapter switches from connection to disconnection with external electronic devices, switches from disconnection to connection, and switches from power adapter to external electronic devices while maintaining connection but switching to power off and from power off to power on.

[0070] Furthermore, in response to the fulfillment of the second trigger condition, the power adapter switches the feedback path from a low-power state to an operating state via the secondary-side controller. This establishes feedback control through the feedback path, enabling it to provide a feedback signal to the primary-side controller. For example, when switching the feedback path from a low-power state to an operating state, the secondary-side controller can begin transmitting current to the feedback path, ensuring the current in the feedback path is greater than zero and that the feedback path operates, such as by illuminating the LED included in the feedback path. After the LED illuminates, the phototransistor responds to the LED to transmit the feedback signal.

[0071] Reference Figure 1 The feedback path is connected to the feedback detection terminal of the primary-side controller. It should be noted that when the feedback path is in a low-power state, such as when the current in the feedback path is 0, the voltage V at the feedback detection terminal of the primary-side controller... FBThe voltage is pulled high by internal circuitry (such as pull-up resistors) to a level close to the highest voltage inside the primary-side controller. Based on this, when the feedback path switches from a low-power state to an operating state, the current in the feedback path switches to a value greater than 0. At this time, the primary-side controller detects the voltage change at the feedback detection terminal connected to the feedback path due to the state switch of the feedback path, such as a decrease from a high level to a low level, a voltage change indicating a falling edge, or a level transition. The voltage change is detected by a detection module inside the primary-side controller. For example, an edge detection module is used to detect whether the voltage change is a rising edge or a falling edge. The input of the edge detection module is the voltage at the feedback detection terminal, and the output is a level signal. This level signal is transmitted to the control module inside the primary-side controller so that the control module responds to the level signal to control the duty cycle of the main power switch.

[0072] Further testing is needed to determine if the voltage change meets the wake-up conditions. This voltage change requires analysis of the voltage at the feedback detection terminal during the monitoring period. The voltage at the feedback detection terminal changes with the brightness of the LED, and consequently, it is affected by changes in the current along the feedback path.

[0073] Correspondingly, the wake-up condition may include a falling edge in the voltage at the feedback detection terminal, that is, the voltage at the feedback detection terminal gradually decreases during the monitoring period, forming a negative slope (dV). FB / dt<0); The wake-up condition may also include the voltage at the feedback detection terminal being less than the preset wake-up voltage. That is, once the voltage at the feedback detection terminal drops from a high level and is less than the preset wake-up voltage, the wake-up condition for the primary side controller is met. The wake-up condition may also include the duration for which the voltage at the feedback detection terminal is less than the preset wake-up voltage reaching the preset wake-up duration. That is, when the voltage at the feedback detection terminal drops from a high level and is less than the preset wake-up voltage, wake-up is not triggered directly. Instead, the duration for which the voltage at the feedback detection terminal is less than the preset wake-up voltage is monitored to see if the preset wake-up duration is reached. If it is, the wake-up condition is determined to be met and wake-up is triggered, thereby avoiding false triggering caused by voltage fluctuations at the feedback detection terminal.

[0074] Regarding the three wake-up conditions mentioned above, determining whether a voltage change meets the wake-up condition based on whether a falling edge occurs has a fast response speed but a higher risk of false triggering, offering a high response rate. Determining whether a voltage change meets the wake-up condition based on whether the voltage is below the preset wake-up voltage for a specified duration has a slower response speed but a lower risk of false triggering, offering higher reliability. Determining whether a voltage change meets the wake-up condition based on whether the voltage is below the preset wake-up voltage falls between the two methods in terms of response speed and risk of false triggering. In practical applications, these wake-up conditions can be used individually or in any combination. When used in combination, after detecting a falling edge, it can be further determined whether the voltage at the feedback detection terminal is below the preset wake-up voltage and maintained for a preset wake-up duration, thus balancing response speed and anti-interference capability.

[0075] It should be noted that the preset wake-up voltage can be determined based on the noise interference in the primary-side controller and feedback path, as well as the health status of each device in the feedback path. If the noise interference in the primary-side controller and feedback path is relatively small (e.g., jitter of tens of mV), the preset wake-up voltage should be set to less than or equal to 2.5V to avoid frequent wake-ups of the primary-side controller, thus avoiding wasted power. If the health status of the devices in the feedback path indicates a high degree of aging, the preset wake-up voltage should be set to greater than or equal to 0.2V to avoid failure to wake up due to device aging. Of course, 2.5V and 0.2V are merely examples and are not limited to these values.

[0076] When the voltage change meets the wake-up condition, the primary side controller exits the primary side regulation mode and enters the secondary side regulation mode. In the secondary side regulation mode, the primary side controller controls the switching control parameters of the main power switch of the primary side circuit according to the feedback signal provided by the feedback path.

[0077] Therefore, this embodiment only requires controlling the on / off state of the feedback path (the current value of the feedback path) to wake up the primary-side controller. Compared to traditional technologies that require the secondary-side controller to send multiple pulses or specific coded signals, and the primary-side controller to perform complex decoding to achieve wake-up, this embodiment effectively reduces the complexity of the control logic and the manufacturing cost, while ensuring the reliability of wake-up. Furthermore, this embodiment limits the wake-up of the feedback circuit to be performed first, that is, the feedback path switches from a low-power state to a working state, then the primary-side controller enters the secondary-side adjustment mode, and finally the secondary-side controller increases the output voltage from the first voltage to the second voltage. This effectively avoids excessively high output voltage caused by increasing the output voltage to the second voltage before the feedback circuit switches to the working state and / or before the primary-side controller enters the secondary-side adjustment mode. In other words, this embodiment can ensure that the output voltage is stable during the process of restoring the output voltage to the normal working voltage. In addition, the phased control of each node avoids control conflicts. During the gradual increase of the second voltage, it can also reduce the surge current or voltage change caused by the power-on connection of external electronic devices, making the voltage and current of the entire power adapter relatively stable.

[0078] For example, after the primary side controller enters the secondary side adjustment mode, the output voltage is adjusted from the first voltage to the second voltage by the secondary side controller. The second voltage is the output voltage of the power adapter in normal power supply mode, and the second voltage is greater than the first voltage, such as 5V.

[0079] When the power adapter is in normal power supply mode, that is, out of low standby mode, the primary side controller responds to the feedback signal provided by the feedback path and controls the switching control parameters of the main power switch according to the auxiliary winding voltage of the second voltage, so as to stabilize the output voltage within the voltage range corresponding to the second voltage, thereby achieving the purpose of powering external electronic devices.

[0080] On the other hand, embodiments of this application also provide a power adapter, for example, Figure 1 A circuit diagram of the power adapter is shown. (Refer to...) Figure 1 It can be seen that the power adapter includes a primary side circuit, a secondary side circuit, and a feedback path disposed between the primary side circuit and the secondary side circuit. The primary side circuit includes a primary side controller (1). st The secondary-side circuit includes a secondary-side controller (2). nd The feedback path is used to transmit the feedback signal provided by the secondary controller to the primary controller. For example, the feedback path includes light-emitting diodes and phototransistors. The secondary-side controller is used to adjust the output voltage to a first voltage in response to the fulfillment of a first trigger condition, wherein the first voltage is a target low voltage that can maintain the operation of the secondary-side controller; The primary-side controller is used to generate a reference voltage based on the primary-side voltage corresponding to the first voltage, and to enter the primary-side regulation mode based on the reference voltage; The secondary-side controller is also used to control the feedback path to enter a low-power state after the primary-side controller enters the primary-side adjustment mode.

[0081] Continue to refer to Figure 1 The power adapter also includes a transformer, a main power switch for the primary circuit, a blocking switch for the secondary circuit, an AC-DC converter, a rectifier, and several resistors. The primary circuit is connected to the primary winding of the transformer, and the secondary circuit is connected to the secondary winding of the transformer.

[0082] by Figure 1 The circuit diagram of the power adapter shown is based on this. Figure 5 A flowchart illustrating an example of a power adapter entering a low standby mode is shown. Figure 6 A flowchart illustrating an example of a power adapter exiting low standby mode is shown.

[0083] Reference Figure 5 Secondary controller 2 nd After receiving a command instructing the power adapter to switch to low standby mode, the controller opens the blocking switch on the secondary side circuit and controls the output voltage V. o (e.g., 5V) drops to the first voltage V 2nd_ZSM (e.g., 3V), then the primary-side controller samples the auxiliary winding voltage and compares it with the auxiliary winding voltage V. aux If the voltage is less than the threshold voltage (e.g., 10V), and the auxiliary winding voltage V aux The voltage is less than the threshold voltage and remains below it for a first duration Y. Primary side controller 1 st The controller then generates a reference voltage. After obtaining the reference voltage, the primary-side controller 1... st The controller then enters a side adjustment mode.

[0084] Furthermore, the secondary controller 2 nd Controller monitors output voltage V o Drop to the first voltage V 2nd_ZSMAnd the duration of the duration, if the duration reaches the second duration X, the secondary controller 2 nd The controller then controls the current I in the feedback path. cathode When the value is 0, it means that current is no longer transmitted to the feedback path, causing the feedback path to enter a low-power state, and the power adapter switches to low standby mode and stops supplying power to external electronic devices. At this time, the primary side controller 1... st The pull-up resistor of the controller makes the voltage at the feedback pin (i.e., the voltage at the feedback detection terminal mentioned above) V FB It presents a high level of accuracy.

[0085] When the power adapter enters low standby mode, the output voltage in the secondary circuit is reduced to a first voltage, and the reference voltage is calculated using the auxiliary winding voltage sampled in real time by the primary controller. This process is a reverse calculation, incorporating losses from components such as the transformer winding and main power switch, effectively compensating for errors caused by these components. Furthermore, the secondary controller is directly connected to the feedback path, directly controlling the feedback path circuitry and avoiding power consumption and control delays caused by indirect connections.

[0086] Reference Figure 6 Secondary controller 2 nd After the controller receives a command instructing the power adapter to exit low standby mode, the current I in its control feedback path... cathode Greater than 0. Correspondingly, primary side controller 1 st Controller feedback pin voltage V FB Will follow I cathode The change in voltage V of the feedback pin will produce a corresponding change. FB This is indicated by a falling edge forming from the high level downwards, or by the feedback pin voltage V. FB Less than the preset wake-up voltage V FB_ZSM_DIS (Low level), or, feedback pin voltage V FB Less than the preset wake-up voltage V FB_ZSM_DIS The duration of the wake-up time reaches the preset wake-up time t. FB_ZSM_DIS Then, it represents the primary side controller 1. st The controller received a feedback signal. Primary controller 1 st The controller responds to the feedback signal, exits the primary-side adjustment mode, and enters the secondary-side adjustment mode.

[0087] Furthermore, the secondary controller 2 nd Controller controls I cathode Once the value is greater than 0, it establishes feedback control through the feedback path and sets the output voltage V. oFrom the first voltage V 2nd_ZSM Adjust to the second voltage (e.g., 5V), and simultaneously close the blocking switch of the secondary circuit. At this time, the power adapter exits the low standby mode and begins to supply power to external electronic devices.

[0088] In a complete combined embodiment, the secondary-side controller determines a first voltage based on the upper limit of its undervoltage lockout threshold range and a preset voltage margin. After detecting a disconnection between an external electronic device and the output of the power adapter via a configuration channel, the output voltage is reduced to the first voltage. The primary-side controller samples the auxiliary winding voltage. After the auxiliary winding voltage meets a preset stability condition and remains stable for a first duration, it generates a reference voltage based on multiple auxiliary winding voltage sampling values ​​collected within the first duration and enters a primary-side regulation mode based on the reference voltage. After the output voltage remains within the voltage range corresponding to the first voltage for a second duration, the secondary-side controller stops supplying current to the optocoupler in the feedback path, causing the feedback path to enter a low-power state. When an external electronic device is detected, the secondary-side controller resumes supplying current to the optocoupler; the primary-side controller first detects the feedback detection terminal voltage V. FB Upon the falling edge of the signal, the feedback detection terminal voltage is confirmed to be lower than the preset wake-up voltage and maintained for a preset wake-up duration to jointly confirm that the wake-up condition is met. After the primary-side controller exits the primary-side adjustment mode and enters the secondary-side adjustment mode, the secondary-side controller restores the output voltage from the first voltage to the second voltage.

[0089] Furthermore, the complete logic control described above, which uses voltage and current changes to switch modes throughout the entire process, eliminates the need for coded signal transmission, and consequently eliminates the need for encoding and decoding devices. This not only simplifies the control logic but also simplifies the overall architecture and reduces hardware costs.

[0090] Furthermore, Figure 7 This illustrates the auxiliary winding voltage V during different time periods as the power adapter switches from normal power supply mode to low standby mode and back to normal power supply mode. aux The current I in the feedback path cathode , voltage V at the feedback detection terminal FB and output voltage V o The timing diagram.

[0091] Figure 7 During the period from 0 to t0, the power adapter is in normal power supply mode, supplying power to external electronic devices. During this period, the control output voltage V is... o The output voltage V in normal power supply mode nor and the current I in the control feedback path cathodeThis is the current value under normal power supply mode; correspondingly, the voltage V at the feedback detection terminal. FB This is the voltage value under normal power supply mode, and the output voltage V o The current I in the feedback path cathode and the voltage V at the feedback detection terminal FB All remain unchanged. Due to deviations in the transformer windings and other components, the auxiliary winding voltage V... aux There is a certain range of fluctuation.

[0092] During the time period t0-t1, if the first trigger condition is determined to be met at time t0, the secondary controller 2... nd Controller controls the output voltage V o Decrease to V 2nd_ZSM Due to the secondary controller 2 nd The controller will control the current I in the feedback path. cathode Size, to the primary side controller 1 st The controller sends a feedback signal to enable the primary controller 1. st The controller adjusts the switching control parameters of the main power switch to ensure the output voltage V. o The magnitude of the voltage, at this time, corresponds to the output voltage V. o Decrease to V 2nd_ZSM Secondary controller 2 nd The controller controls the current I in the feedback path. cathode Increase, so that the primary side controller 1 st The controller controls the main converter switch to increase the energy transferred from the transformer to the secondary side; correspondingly, the voltage V at the feedback detection terminal... FB With the current I of the feedback path cathode Increase and decrease, auxiliary winding voltage V aux The state is the same as the state during the time period 0-t0.

[0093] During the time period t1-t2, the output voltage V o Keep in V 2nd_ZSM The current I in the feedback path cathode and the voltage V at the feedback detection terminal FB All remain unchanged, based on the output voltage V o With auxiliary winding voltage V aux The corresponding relationship, auxiliary winding voltage V aux Reduced to primary side controller 1 st Controller threshold voltage V 1nd_ZSM .

[0094] At time t2, the power adapter switches to low standby mode. At this time, the secondary controller 2... nd The controller controls the current I in the feedback path. cathode The value is 0, correspondingly, the voltage V at the feedback detection terminal is 0. FB Pulled up to high level V DD .

[0095] During the time period t2-t3, the power adapter is in low standby mode, and the auxiliary winding voltage V aux The current I in the feedback path cathode , voltage V at the feedback detection terminal FB and output voltage V o The state remains unchanged, or fluctuates within a certain range.

[0096] During the time period t3-t4, if the second trigger condition is determined to be met at time t3, the secondary controller 2... nd The controller controls the current I in the feedback path. cathode Increasing the value to the value within the time period t1-t2 corresponds to an increase in the voltage V at the feedback detection terminal. FB Pulled down to a low level (less than the preset wake-up voltage V) FB_ZSM_DIS ), until the wake-up condition is determined at time t4, secondary controller 2 nd Controller controls the output voltage V o The output voltage V rises to normal power supply mode. nor Correspondingly, the current I in the feedback path cathode , voltage V at the feedback detection terminal FB and auxiliary winding voltage V aux All values ​​are restored to the values ​​under normal power supply mode, that is, the values ​​within the time period 0-t0. At this time, the power adapter switches to normal power supply mode.

[0097] Furthermore, embodiments of this application also provide an electronic device, for example, Figure 8 A schematic diagram of the electronic device is shown. (Refer to...) Figure 8 It can be seen that electronic devices include: The device body includes a load circuit; A power adapter disposed on or connected to the device body and used to supply power to the load circuit; The power adapter includes a primary side circuit, a secondary side circuit, and a feedback path disposed between the primary side circuit and the secondary side circuit. The primary side circuit includes a primary side controller, the secondary side circuit includes a secondary side controller, and the feedback path is used to transmit the feedback signal provided by the secondary side controller to the primary side controller. The secondary-side controller is used to adjust the output voltage to a first voltage in response to the fulfillment of a first trigger condition, wherein the first voltage is a target low voltage that can maintain the operation of the secondary-side controller; The primary-side controller is used to generate a reference voltage based on the primary-side voltage corresponding to the first voltage, and to enter the primary-side regulation mode based on the reference voltage; The secondary-side controller is also used to control the feedback path to enter a low-power state after the primary-side controller enters the primary-side adjustment mode.

[0098] For example, electronic devices may include laptops, tablets, rollable laptops, laptops that can switch between portrait and landscape modes, etc. Correspondingly, load circuits include display circuits, audio processing circuits, speaker array circuits, motor drive circuits, etc. Furthermore, the load circuits that require power supply may be different for the same electronic device in different operating states.

[0099] Taking a laptop as an example, when a laptop is powered on and has not been used for a long time, the laptop automatically switches to hibernation mode. At this time, the laptop does not need normal power supply; it only needs to remain in hibernation mode. Correspondingly, an indicator signal can be sent to the power adapter to cause the power adapter to enter a low-power mode, thereby reducing the power supplied to the laptop. If the laptop is powered off, another indicator signal can be sent to the power adapter to cause the power adapter to enter a low standby mode, thereby stopping power supply to the laptop and reducing the overall standby power consumption of the electronic device.

[0100] When the device and power adapter are in a movable connection (e.g., plugged in or unplugged), the power adapter can retain the wake-up detection function of the configured channel in low standby mode, allowing for rapid restoration of load power even in low-power conditions. Furthermore, the plugging / unplugging action can indicate whether the power mode is in low standby or normal operating mode.

[0101] When the device and power adapter are integrated, such as when the power adapter is built into the device, the device can actively control the power supply mode based on load status, user operation, or temperature status. Temperature status includes the temperature of both the device itself and the power adapter. For example, if the user instructs the power supply to be paused, the power adapter can be controlled to enter a low standby mode. Similarly, if the temperature of the device itself and / or the power adapter is too high, the power adapter can be controlled to enter a low standby mode. Furthermore, for devices with high power consumption, the power adapter generates a lot of heat when supplying power, and there is also some loss when transferring heat outward. Therefore, for electronic devices where the device body and power adapter are integrated, the standby heat load inside the device can be reduced; for electronic devices where the device body and power adapter are connected, the no-load power consumption can be reduced when the device is disconnected or the logic stops charging, so as to reduce the heat of the power adapter and thus reduce power consumption.

[0102] Since the principle of solving the problem by the electronic device in this application embodiment is similar to that of the power adapter described above, the implementation of the electronic device can refer to the implementation of the power adapter described above, and the repeated parts will not be described again.

[0103] Furthermore, although exemplary embodiments have been described herein, their scope includes any and all embodiments based on this application that have equivalent elements, modifications, omissions, combinations (e.g., schemes involving intersections of various embodiments), adaptations, or alterations. Elements in the claims will be interpreted broadly based on the language used in the claims and are not limited to the examples described in this specification or during the implementation of this application, which will be interpreted as non-exclusive. Therefore, this specification and examples are intended to be considered illustrative only, and the true scope and spirit are indicated by the following claims and the full scope of their equivalents.

[0104] The above description is intended to be illustrative and not restrictive. For example, the above examples (or one or more of them) can be used in combination with each other. Other embodiments may be used by those skilled in the art upon reading the above description. Furthermore, in the above detailed description, various features may be grouped together to simplify the application. This should not be construed as an intention that a disclosed feature not claimed is necessary for any claim. Rather, the subject matter of this application may be less than all the features of a particular disclosed embodiment. Thus, the following claims are incorporated herein by reference as examples or embodiments, wherein each claim is an independent, separate embodiment, and these embodiments are contemplated as being possible in various combinations or arrangements. The scope of this application should be determined by reference to the appended claims and the full scope of their equivalents.

[0105] The foregoing has described in detail several embodiments of this application, but this application is not limited to these specific embodiments. Those skilled in the art can make various variations and modifications based on the concept of this application, and all such variations and modifications should fall within the scope of protection claimed in this application.

Claims

1. A control method for a power adapter, comprising: In response to the fulfillment of a first trigger condition, the output voltage is adjusted to a first voltage via the secondary-side controller of the power adapter. The first voltage is a target low voltage that can sustain the operation of the secondary-side controller. A reference voltage is generated based on the primary-side voltage corresponding to the first voltage through the primary-side controller of the power adapter; After the primary-side controller enters the primary-side regulation mode based on the reference voltage, it enters a low-power state through the feedback path used by the secondary-side controller to provide feedback signals to the primary-side controller.

2. The control method according to claim 1, wherein, The first voltage is determined based on the undervoltage lockout shutdown threshold range of the secondary-side controller; The first voltage is greater than or equal to the upper limit of the undervoltage lockout threshold range, and the voltage difference between the first voltage and the upper limit is less than or equal to a preset voltage margin.

3. The control method according to claim 1 or 2, wherein generating a reference voltage based on the primary side voltage corresponding to the first voltage comprises: The auxiliary winding voltage of the transformer of the power adapter is sampled by the primary side controller to obtain multiple auxiliary winding voltage sample values, and the auxiliary winding voltage has a corresponding relationship with the output voltage. If the auxiliary winding voltage meets the preset stability condition and continues for a first duration, the multiple auxiliary winding voltage sampling values ​​collected within the first duration are processed according to the preset processing method to obtain the reference voltage. The preset processing method includes average value calculation and / or digital filtering.

4. The control method according to claim 3, wherein the primary-side controller enters a primary-side regulation mode based on the reference voltage, comprising: The primary-side controller adjusts the switching control parameters of the main power switch of the primary-side circuit based on the comparison result between the auxiliary winding voltage and the reference voltage, so as to change the energy transmitted to the secondary side via the transformer and maintain the output voltage within the voltage range corresponding to the first voltage. Stop responding to the feedback signals provided by the feedback path; Specifically, when the auxiliary winding voltage is less than the reference voltage, the energy transmitted to the secondary side via the transformer is increased; When the auxiliary winding voltage is greater than the reference voltage, the energy transmitted to the secondary side via the transformer is reduced.

5. The control method according to claim 3 or 4, wherein entering a low-power state via a feedback path used by the secondary-side controller to provide a feedback signal to the primary-side controller, includes: When the output voltage is maintained within the voltage range corresponding to the first voltage for a duration of a second duration, the system enters a low-power state through the feedback path used by the secondary-side controller to provide a feedback signal to the primary-side controller; wherein the second duration is longer than the first duration. The process of putting the feedback path into a low-power state includes at least one of the following: Disconnect the feedback path; Reduce the current in the feedback path; Stop the feedback path from providing feedback signals for secondary-side adjustment to the primary-side controller; The feedback path is controlled to retain the wake-up detection function or the state retention function; This enables other isolated feedback paths to enter a low-power or non-feedback operating state.

6. The control method according to claim 5 further includes: In response to the fulfillment of the second triggering condition, the secondary-side controller switches the feedback path from the low-power state to the working state, so that the feedback path provides a feedback signal to the primary-side controller. The primary-side controller detects the voltage change at the feedback detection terminal connected to the feedback path due to the state switching of the feedback path; When the voltage change meets the wake-up condition, the primary-side controller exits the primary-side regulation mode and enters the secondary-side regulation mode. The wake-up condition includes one of the following: The voltage at the feedback detection terminal generates a falling edge; The voltage at the feedback detection terminal is less than the preset wake-up voltage; The duration for which the voltage at the feedback detection terminal is less than the preset wake-up voltage reaches the preset wake-up duration.

7. The control method according to claim 6 further includes: After the primary-side controller enters the secondary-side adjustment mode, the secondary-side controller adjusts the output voltage from the first voltage to the second voltage. The second voltage is the output voltage of the power adapter in normal power supply mode, and the second voltage is greater than the first voltage.

8. The control method according to claim 6, The first triggering condition includes one of the following: An external electronic device was detected to be disconnected from the output of the power adapter. The voltage state of the configuration channel of the power adapter is detected to meet the preset low standby conditions; A low standby command is received through the configuration channel of the power adapter; The second triggering condition includes one of the following: An external electronic device was detected connected to the output terminal of the power adapter. The voltage state of the configuration channel of the power adapter is detected to meet the preset wake-up conditions; The wake-up command is received through the configuration channel of the power adapter.

9. A power adapter, comprising a primary side circuit, a secondary side circuit, and a feedback path disposed between the primary side circuit and the secondary side circuit, wherein the primary side circuit includes a primary side controller, the secondary side circuit includes a secondary side controller, and the feedback path is used to transmit a feedback signal provided by the secondary side controller to the primary side controller. The secondary-side controller is used to adjust the output voltage to a first voltage in response to the fulfillment of a first trigger condition, wherein the first voltage is a target low voltage that can maintain the operation of the secondary-side controller; The primary-side controller is used to generate a reference voltage based on the primary-side voltage corresponding to the first voltage, and to enter the primary-side regulation mode based on the reference voltage; The secondary-side controller is also used to control the feedback path to enter a low-power state after the primary-side controller enters the primary-side adjustment mode.

10. An electronic device, comprising: The device body includes a load circuit; A power adapter disposed on or connected to the device body and used to supply power to the load circuit; The power adapter includes a primary side circuit, a secondary side circuit, and a feedback path disposed between the primary side circuit and the secondary side circuit. The primary side circuit includes a primary side controller, the secondary side circuit includes a secondary side controller, and the feedback path is used to transmit the feedback signal provided by the secondary side controller to the primary side controller. The secondary-side controller is used to adjust the output voltage to a first voltage in response to the fulfillment of a first trigger condition, wherein the first voltage is a target low voltage that can maintain the operation of the secondary-side controller; The primary-side controller is used to generate a reference voltage based on the primary-side voltage corresponding to the first voltage, and to enter the primary-side regulation mode based on the reference voltage; The secondary-side controller is also used to control the feedback path to enter a low-power state after the primary-side controller enters the primary-side adjustment mode.

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