Power supply device

Abstract

A power supply device is provided. The power supply device includes a power converter and a controller. The controller controls the power converter to generate an output power. The controller includes a first detection circuit and a second detection circuit. The first detection circuit detects the output power to obtain a first detection result. The first detection result is a variation of an output current value of the output power. The second detection circuit detects an electrical characteristic other than the output current value to obtain a second detection result. The controller determines whether to limit an output of the output power in accordance with a relationship between the first detection result and the second detection result.

Description

Technical Field

[0001] This invention relates to the field of power supply, and more particularly to a power supply device. Background Technology

[0002] Current power supply devices have a precise power detection method. Through the aforementioned precise power detection method, the controller of the power supply device can obtain at least the output current value of the output power supply, and control the operation of the power supply device based on the output current value, thereby complying with current safety standards (such as safety standards IEC 60950-1, IEC 62368-1, IEC 60065).

[0003] However, when the aforementioned precise power detection method fails, the controller cannot control the operation of the power supply device. Therefore, the power supply device may fail to meet safety standards, or even malfunction or cause safety hazards. Summary of the Invention

[0004] The present invention provides a power supply device that can determine whether a precise power detection method has failed, and provide a power supply method corresponding to whether the precise power detection method has failed.

[0005] The power supply device of the present invention includes a power converter and a controller. The controller is coupled to the power converter. The controller controls the power converter to generate an output power supply. The controller includes a first detection circuit and a second detection circuit. The first detection circuit detects the output power supply to obtain a first detection result. The first detection result is a change in the output current value of the output power supply. The second detection circuit detects electrical characteristics other than the output current value to obtain a second detection result. The controller limits the output of the output power supply based on the relationship between the first detection result and the second detection result.

[0006] Based on the above, the first detection circuit detects the output power supply to obtain a first detection result. The first detection result is the change in the output current value of the output power supply. The second detection circuit detects electrical characteristics other than the output current value to obtain a second detection result. The controller determines whether to limit the output power supply based on the relationship between the first and second detection results. Therefore, the controller can determine whether the detection of the first detection circuit has failed based on the second detection result. When the detection of the first detection circuit is determined to have failed, the controller causes the power supply device to limit the output power supply. In this way, the power supply device can avoid possible misoperation and / or safety hazards when the first detection result fails.

[0007] To make the above features and advantages of the present invention more apparent and understandable, specific embodiments are described below in conjunction with the accompanying drawings. Attached Figure Description

[0008] Figure 1 This is a schematic diagram of a power supply device according to the first embodiment of the present invention;

[0009] Figure 2 This is a schematic diagram of a power supply device according to a second embodiment of the present invention;

[0010] Figure 3 This is a schematic diagram of a power supply device according to a third embodiment of the present invention;

[0011] Figure 4 This is a schematic diagram of a power supply device according to the fourth embodiment of the present invention;

[0012] Figure 5 This is a schematic diagram of a power supply device according to the first embodiment supplying power to a load via a Type-C communication cable.

[0013] Explanation of reference numerals in the attached figures

[0014] 100, 200, 300, 400: Power supply devices

[0015] 110, 210, 310, 410: Power converters

[0016] 120, 220, 320, 420: Controller

[0017] 121, 221, 321, 421: First detection circuit

[0018] 122, 222, 322, 422: Second detection circuit

[0019] 211: Optical Coupler

[0020] 323: Driver

[0021] BSW: Blocking switch

[0022] CB: Communication cable

[0023] CC: Configuration Channel

[0024] CGND: Grounding path

[0025] CO: Output capacitor

[0026] CP: Current path inside the load

[0027] D: Light Emitting Diode

[0028] DO: Output diode

[0029] DR1: First test result

[0030] DR2: Second test result

[0031] GB, GD, GSR: Control signals

[0032] GND1, GND2: Grounding terminals

[0033] Ip: Current source

[0034] Iout: Output current

[0035] LD: Load

[0036] P1: Configuration channel pin for power supply device

[0037] P2: Grounding pin of the power supply unit

[0038] P3: Power pin of the power supply unit

[0039] P4: Load configuration channel pin

[0040] P5: Grounding pin of the load

[0041] P6: Power supply pin for the load

[0042] R1, R2: Resistors

[0043] Rc: Equivalent path resistance

[0044] Rd: Pull-down resistor

[0045] RS: Sensing resistor

[0046] SRSW: Synchronous Rectifier Switch

[0047] T: Phototransistor

[0048] VD, VR: Voltage difference

[0049] VB: Voltage Source

[0050] Vbus: Power Channel

[0051] VO: Output power Detailed Implementation

[0052] Reference will now be made in detail to exemplary embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same component reference numerals are used in the drawings and description to denote the same or similar parts.

[0053] Please refer to Figure 1 , Figure 1This is a schematic diagram of a power supply device according to a first embodiment of the present invention. In this embodiment, the power supply device 100 includes a power converter 110 and a controller 120. The controller 120 is coupled to the power converter 110. The controller 120 controls the power converter 110 to generate an output power supply VO. The controller 120 provides a control signal GD. The power converter 110 responds to the control signal GD to generate the output power supply VO. Furthermore, based on the control of the controller 120, the power supply device 100 outputs the output power supply VO to the load LD.

[0054] In this embodiment, the controller 120 includes a first detection circuit 121 and a second detection circuit 122. The first detection circuit 121 detects the output power supply VO to obtain a first detection result DR1. The first detection result DR1 is the change in the output current value of the output power supply VO.

[0055] In this embodiment, the power supply device 100 further includes a sensing resistor RS. The sensing resistor RS is coupled between the output terminal of the power converter 110 and the load LD. The output current Iout of the output power supply VO flows through the sensing resistor RS. Therefore, a voltage difference corresponding to the output current Iout will be generated across the sensing resistor RS. The first detection circuit 121 detects the voltage difference across the sensing resistor RS and obtains a first detection result DR1 corresponding to the output current value based on the voltage difference across the sensing resistor.

[0056] It should be noted that the first detection circuit 121 provides a precise detection method. The first detection result DR1 is equal to the change in the output current value. Therefore, the controller 120 responds to the first detection result DR1 to control the power converter 110, thereby ensuring that the power supply device 100 complies with safety standards (e.g., safety standard IEC 60950). For example, the controller 120 responds to the first detection result DR1 to control the power converter 110, thereby ensuring that the power supply device 100 complies with the limited power source (LPS) requirements of safety standard IEC 60950. With LPS compliance, based on safety standard IEC 60950, the power supply device 100 does not need to provide a fire enclosure and can use a less expensive HB flammability rating enclosure material. Therefore, with LPS compliance, the cost of the power supply device 100 is reduced.

[0057] In this embodiment, the second detection circuit 122 detects electrical characteristics other than the output current value to obtain a second detection result DR2. The controller 120 determines whether to limit the output power supply VO based on the relationship between the first detection result DR1 and the second detection result DR2. Taking this embodiment as an example, the controller 120 determines whether to stop the power supply device 100 from providing the output power supply VO to the load LD based on the relationship between the first detection result DR1 and the second detection result DR2.

[0058] In some embodiments, the controller 120 determines whether to reduce the output power supply voltage or current VO based on the relationship between the first detection result DR1 and the second detection result DR2.

[0059] In this embodiment, the second detection result DR2 is a change in electrical characteristics other than the output current value. However, the trend of the change in the second detection result DR2 is still positively or negatively correlated with the change in the output current value. The controller 120 determines whether to limit the output power supply VO based on the correlation between the first detection result DR1 and the second detection result DR2. For example, when the detection resistor RS is short-circuited, the first detection result DR1 will not change. However, the second detection result DR2 will change. That is, the second detection result DR2 is unrelated to the first detection result DR1. Therefore, if the load LD can continuously receive the output power supply VO, the controller 120 will determine that the first detection method has failed. The controller 120 causes the power supply device 100 to limit the output power supply VO.

[0060] It is worth mentioning that the controller 120 determines whether to limit the output power supply VO of the power supply device 100 based on the relationship between the first detection result DR1 and the second detection result DR2, for example, by stopping the power supply device 100 from providing the output power VO to the load LD. The controller 120 can determine whether the detection of the first detection circuit 121 has failed based on the second detection result DR2. When the detection of the first detection circuit 121 is determined to be failed, the power supply device 100 limits the output power VO. In this way, the power supply device 100 can avoid misoperation and / or safety hazards caused by the failure of the first detection circuit 121.

[0061] In this embodiment, the power supply device 100 further includes a blocking switch BSW. A first terminal of the blocking switch BSW is coupled to the output terminal of the power converter 110. A second terminal of the blocking switch BSW is coupled to the load LD. A control terminal of the blocking switch BSW is coupled to a controller 120. The controller 120 turns on the blocking switch BSW to cause the power supply device 100 to provide output power VO to the load LD. The controller 120 turns off the blocking switch BSW to cause the power supply device 100 to stop providing output power VO to the load LD. In this embodiment, when the detection of the first detection circuit 121 is determined to be normal, the controller 120 provides a control signal GB with a first voltage level (e.g., a high voltage level) to turn on the blocking switch BSW. Therefore, the power supply device 100 provides output power VO to the load LD. On the other hand, when the detection of the first detection circuit 121 is determined to be faulty, the controller 120 provides a control signal GB with a second voltage level (e.g., a low voltage level) to turn off the blocking switch BSW. Therefore, the power supply device 100 will not provide the output power VO to the load LD.

[0062] In this embodiment, the power converter 110 can be implemented by one or any combination of a flyback power converter, a boost converter, a buck converter, an LLC resonant power converter, an asymmetrical half-bridge (AHB) power converter, or other types of converters. In this embodiment, the load LD can be an electronic device or an electrical appliance.

[0063] In this embodiment, the second detection circuit 122 can obtain at least one second detection result DR2 through at least one detection method. Several embodiments will be used to illustrate possible ways of obtaining the second detection result DR2 below.

[0064] Please refer to Figure 2 , Figure 2This is a schematic diagram of a power supply device according to a second embodiment of the present invention. In this embodiment, the power supply device 200 includes a power converter 210, a controller 220, a blocking switch BSW, and a sensing resistor RS. The power converter 210 includes a primary and a secondary device. The power converter 210 includes an optocoupler 211. The optocoupler 211 includes a light-emitting diode D and a phototransistor T. For example, the anode of the light-emitting diode D is coupled to the output terminal of the power converter 210. The cathode of the light-emitting diode D is coupled to the controller 220. The present invention is not limited thereto. The secondary device of the power converter 210 includes an output diode DO and an output capacitor CO. The cathode of the output diode DO is used as the output terminal of the power converter 210. The first terminal of the output capacitor CO is coupled to the cathode of the output diode DO. The second terminal of the output capacitor CO is coupled to the ground terminal GND1. The first terminal of the blocking switch BSW is coupled to the cathode of the diode. The sensing resistor RS is coupled between the second terminal of the output capacitor CO and the load LD.

[0065] In this embodiment, the first terminal of the phototransistor T is coupled to a voltage source VB. The second terminal of the phototransistor T is coupled to a ground terminal GND2. In one embodiment, the voltage source VB may be provided by a primary control unit (not shown) on the same side as the phototransistor T. The first terminal of the phototransistor T is coupled to a connection node FB. Depending on the type of power converter 210, the ground terminal GND2 is different from the ground terminal GND1. In this embodiment, the controller 220 may, for example, receive an output power supply VO and adjust the voltage value at the cathode of the light-emitting diode D based on changes in the output power supply VO. Assuming the voltage value of the output power supply VO is approximately constant, the output current value of the output power supply VO is related to the current value flowing through the light-emitting diode D. Therefore, a change in the output current value of the output power supply VO will change the conduction current of the phototransistor T, thereby affecting the voltage level or charging / discharging state at the connection node FB. The controller 220 then stabilizes the output power supply VO based on the voltage level or charging / discharging state of the connection node FB. For example, the power converter 210 includes a power switch. The power switch performs switching operations based on control signals provided by the controller 220. The controller 220 adjusts the frequency or duty cycle of the control signal based on the voltage level or charging / discharging status of the connection node FB, thereby stabilizing the output power supply VO.

[0066] In this embodiment, resistor R1 can be provided to limit the current flowing through the light-emitting diode D. Resistor R2 can be provided to limit the current flowing through the phototransistor T.

[0067] The controller 220 includes a first detection circuit 221 and a second detection circuit 222. The detection operation of the first detection circuit 221 is generally similar to the detection operation of the first detection circuit 121 in the first embodiment, and therefore will not be described again.

[0068] In this embodiment, the output current value of the output power supply VO is related to the current value flowing through the light-emitting diode D. For example, the larger the output current value of the output power supply VO, the larger the voltage value at the cathode of the light-emitting diode D. The smaller the current value flowing through the light-emitting diode D. Therefore, the second detection circuit 222 detects the current value flowing through the light-emitting diode. The second detection result DR2 is the change in the current value flowing through the light-emitting diode D. When the second detection result DR2 is positively correlated with the first detection result DR1, it means that the second detection result DR2 and the first detection result DR1 are contradictory. If the load LD continuously receives the output power supply VO, the first detection result DR1 is determined to be invalid. The invalidation of the first detection result DR1 may cause the power supply device 200 to fail to meet the LPS requirements. Therefore, the controller 220 controls the power supply device 200 to limit the output of the output power supply VO. In this embodiment, a first threshold and a second threshold are provided, and the second threshold is greater than the first threshold. When the change in the first detection result DR1 is less than the first threshold and the change in the current flowing through the light-emitting diode D is greater than the second threshold, this indicates that the second detection result DR2 has a significant change, while the first detection result DR1 has a very small change (or no change). Therefore, the trends of the second detection result DR and the first detection result DR1 are not consistent. If the load LD continuously receives the output power VO, the first detection result DR1 is determined to be faulty. Therefore, the controller 220 controls the power supply device 200 to limit the output of the output power VO. Furthermore, when the second detection result DR2 is negatively correlated with the first detection result DR1, this indicates that the trends of the second detection result DR2 and the first detection result DR1 are consistent. The first detection result DR1 is determined to be normal. Therefore, the controller 220 causes the power supply device 200 to provide the output power VO to the load LD.

[0069] Please refer to Figure 3 , Figure 3This is a schematic diagram of a power supply device according to a third embodiment of the present invention. In this embodiment, the power supply device 300 includes a power converter 310, a controller 320, a blocking switch BSW, and a sensing resistor RS. The power converter 310 includes a synchronous rectifier switch SRSW and an output capacitor CO. Taking this embodiment as an example, one end of the synchronous rectifier switch SRSW is coupled to the first end of the output capacitor CO as an output terminal (the present invention is not limited thereto). In this embodiment, the synchronous rectifier switch SRSW performs synchronous rectification operation in response to the control signal GSR.

[0070] The controller 320 includes a first detection circuit 321 and a second detection circuit 322. The detection operation of the first detection circuit 321 is generally similar to the detection operation of the first detection circuit 121 in the first embodiment, and therefore will not be described again.

[0071] The second detection circuit 322 detects the on-time of the synchronous rectifier switch SRSW. Therefore, the second detection result DR2 is the change in the on-time of the synchronous rectifier switch SRSW. Further, the controller 320 also includes a driver 323. The driver 323 provides a control signal GSR with a duty cycle. The second detection circuit 322 receives the detection control signal GSR and determines the on-time of the synchronous rectifier switch SRSW based on the duty cycle of the control signal GSR. The on-time of the synchronous rectifier switch SRSW is directly related to the output current value.

[0072] In this embodiment, a first threshold and a second threshold are provided, with the second threshold being greater than the first threshold. When the change in the first detection result DR1 is less than the first threshold and the change in the on-time of the synchronous rectifier switch SRSW is greater than the second threshold, this indicates that the second detection result DR2 has a significant change, while the first detection result DR1 has a very small change (or no change). The trends of the second detection result DR and the first detection result DR1 are inconsistent. For example, when the detection resistor RS is short-circuited or open-circuited, the first detection result DR1 will indicate that the output current value is equal to 0 amperes. However, the second detection result DR indicates that the duty cycle of the control signal GSR is greater than a threshold (e.g., 10% or 20%, which is not limited to this invention). When the load LD continuously receives the output power supply VO, the first detection result DR1 is determined to be faulty. Therefore, the controller 320 controls the power supply device 300 to limit the output of the output power supply VO. When the second detection result DR2 is negatively correlated with the first detection result DR1, this indicates that the second detection result DR2 and the first detection result DR1 are contradictory. If the load LD continuously receives the output power VO, the first detection result DR1 is determined to be faulty. Therefore, the controller 320 controls the power supply device 300 to limit the output of the output power VO.

[0073] Furthermore, when the second detection result DR2 is positively correlated with the first detection result DR1, this indicates that the trends of the second detection result DR2 and the first detection result DR1 are consistent. The first detection result DR1 is determined not to have failed. Therefore, the controller 320 causes the power supply device 200 to provide output power VO to the load LD.

[0074] Please refer to Figure 4 , Figure 4 This is a schematic diagram of a power supply device according to a fourth embodiment of the present invention. In this embodiment, the power supply device 400 includes a power converter 410, a controller 420, a blocking switch BSW, and a detection resistor RS. The controller 420 includes a first detection circuit 421 and a second detection circuit 422. The detection operation of the first detection circuit 421 is substantially similar to the detection operation of the first detection circuit 121 in the first embodiment, and therefore will not be repeated.

[0075] In this embodiment, the second detection circuit 422 detects the on-state voltage of the blocking switch BSW. Further, the second detection circuit 422 has prior knowledge of the on-resistance value of the blocking switch BSW when it is in the on state. When the blocking switch BSW is in the on state, the second detection circuit 422 receives the voltage difference between the first and second terminals of the blocking switch BSW and divides this voltage difference by the on-resistance value to obtain the on-state voltage of the blocking switch BSW. The on-state voltage of the blocking switch BSW is directly correlated with the output current value. Therefore, the second detection result DR2 is the change in the on-state voltage value.

[0076] In this embodiment, a first threshold and a second threshold are provided, with the second threshold being greater than the first threshold. When the change in the first detection result DR1 is less than the first threshold and the change in the conduction voltage value is greater than the second threshold, this indicates that the second detection result DR2 has a significant change, while the first detection result DR1 has a very small change (or no change). The trends of the second detection result DR2 and the first detection result DR1 are not consistent. When the load LD continuously receives the output power VO, the first detection result DR1 is determined to be faulty. Therefore, the controller 320 controls the power supply device 300. When the second detection result DR2 is negatively correlated with the first detection result DR1, this indicates that the second detection result DR2 and the first detection result DR1 are contradictory. When the load LD continuously receives the output power VO, the first detection result DR1 is determined to be faulty. Therefore, the controller 320 controls the power supply device 300. Furthermore, when the second detection result DR2 is positively correlated with the first detection result DR1, this indicates that the trends of the second detection result DR2 and the first detection result DR1 are consistent. The first detection result DR1 is determined not to be faulty. Therefore, controller 320 causes power supply device 200 to provide output power VO to load LD.

[0077] Please also refer to Figure 1 as well as Figure 5 , Figure 5 This is a schematic diagram illustrating a power supply device supplying power to a load via a Type-C communication cable, as shown in the first embodiment. In this embodiment, the power supply device 100 also supplies power to the load LD via a Type-C compliant communication cable CB. The communication cable CB includes a power channel Vbus, a configuration channel CC, and a ground channel CGND. The configuration channel CC is coupled between the configuration channel pin P1 of the power supply device 100 and the configuration channel pin P4 of the load LD. The ground channel CGND is coupled between the ground pin P2 of the power supply device 100 and the ground pin P5 of the load LD. The power channel Vbus is coupled between the power pin P3 of the power supply device 100 and the power pin P6 of the load LD. The power supply device 100 also includes a current source Ip or an equivalent circuit. The current source Ip is used to provide a constant current signal to the load LD. The pull-down resistor Rd of the load LD establishes a voltage difference VR across the pull-down resistor Rd according to the constant current signal. The load LD and the power supply device 100 will respond to the voltage difference VR between the two ends of the pull-down resistor Rd to determine whether to communicate or supply the output power VO.

[0078] In this embodiment, the second detection circuit 122 detects the voltage difference VD between the configuration channel pin P1 and the ground channel pin P2 of the power converter 110. Further, the controller 320 can obtain the voltage difference VD between the configuration channel pin P1 and the ground channel pin P2 according to formula (1).

[0079] VD=(i_Iout+i_Ip)×r_Rc+i_Ip×r_Rd………….Formula (1)

[0080] In formula (1), i_Iout represents the current value of the output current Iout, r_Rc represents the resistance value of the equivalent path resistance Rc on the transmission path of the output current Iout, i_Ip represents the current value of the constant current signal, and r_Rd represents the resistance value of the pull-down resistor Rd. In this embodiment, the transmission path includes the power supply channel Vbus, the current path CP inside the load LD, and the configuration channel CC. For ease of explanation, the equivalent path resistance Rc in this embodiment is shown as an example in the configuration channel CC.

[0081] In this embodiment, the current value of the constant current signal is significantly smaller than the current value of the output current Iout. The resistance value of the equivalent path resistance Rc is significantly smaller than the resistance value of the pull-down resistor Rd. Therefore, equation (1) can be simplified to equation (2):

[0082]

[0083] The controller 320 can obtain the voltage difference VR between the two ends of the pull-down resistor Rd according to formula (3).

[0084] VR=i_Ip×r_Rd…………….Formula(3)

[0085] The voltage difference VR between the two ends of the pull-down resistor Rd is equal to the product of the current value of the constant current signal and the resistance value of the pull-down resistor Rd. During power supply, the voltage difference VR is a constant value. Therefore, based on formulas (2) and (3), the voltage difference VD between the configuration channel pin P1 and the ground channel pin P2 is proportional to the current value of the output current Iout. Therefore, the second detection result DR2 of the second detection circuit 122 is the change in voltage difference VD.

[0086] In this embodiment, a first threshold and a second threshold are provided, with the second threshold being greater than the first threshold. When the change in the first detection result DR1 is less than the first threshold and the change in the voltage difference VD is greater than the second threshold, this indicates that the second detection result DR2 has a significant change, while the first detection result DR1 has a very small change (or no change). The trends of the second detection result DR and the first detection result DR1 are not consistent. The first detection result DR1 is determined to be faulty. Therefore, the controller 320 controls the power supply device 300 to limit the output of the output power supply VO. When the second detection result DR2 is negatively correlated with the first detection result DR1, this indicates that the second detection result DR2 and the first detection result DR1 are contradictory. The first detection result DR1 is determined to be faulty. Therefore, the controller 320 controls the power supply device 300 to limit the output of the output power supply VO. Furthermore, when the second detection result DR2 is positively correlated with the first detection result DR1, this indicates that the trend of the second detection result DR2 is consistent with the trend of the first detection result DR1. The first detection result DR1 is determined not to be faulty. Therefore, controller 320 causes power supply device 200 to provide output power VO to load LD.

[0087] Furthermore, when the output current Iout is equal to 0 amperes, the voltage difference VD between the configuration channel pin P1 and the ground channel pin P2 is approximately equal to the voltage difference VR. Therefore, the controller 320 can accurately obtain the output current Iout value according to formula (4).

[0088]

[0089] In summary, the first detection circuit of this invention detects the output power supply to obtain an accurate first detection result. The second detection circuit detects electrical characteristics other than the output current value to obtain a second detection result. The controller can determine whether the detection of the first detection circuit has failed based on the second detection result. When the detection of the first detection circuit is determined to be failed, the controller controls the power supply device to limit the output power supply. The power supply device of this invention can avoid possible misoperation and / or safety hazards when the first detection result fails.

[0090] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A power supply device, characterized in that, The power supply device includes: Power converter; A blocking switch, wherein a first terminal of the blocking switch is coupled to the output terminal of the power converter, and a second terminal of the blocking switch is coupled to the load; and A controller, coupled to the power converter and the stop switch, is configured to control the power converter to provide output power, wherein the controller includes: A first detection circuit is configured to detect the output power supply to obtain a first detection result, wherein the first detection result is a change in the output current value of the output power supply; and A second detection circuit is configured to detect the electrical characteristics of at least one of the power converter and the blocking switch to obtain a second detection result, wherein the electrical characteristics are different from the output current value. The controller determines whether to limit the output of the output power supply based on the relationship between the first detection result and the second detection result.

2. The power supply device according to claim 1, characterized in that, The controller responds to the first detection result to control the power converter, thereby ensuring that the power supply device meets the power-limited power requirements.

3. The power supply device according to claim 1, characterized in that, The power supply device further includes: A sensing resistor is coupled between the output of the power converter and the load. The output current of the output power supply flows through the sensing resistor, and The first detection circuit detects the voltage difference across the detection resistor and obtains the first detection result corresponding to the output current value based on the voltage difference across the detection resistor.

4. The power supply device according to claim 1, characterized in that, The power converter also includes: Optical couplers, including light-emitting diodes, The second detection circuit detects the current flowing through the light-emitting diode. The larger the output current value of the output power supply, the larger the voltage value at the cathode of the light-emitting diode, and the smaller the current value flowing through the light-emitting diode. The second detection result is the change in the current value flowing through the light-emitting diode.

5. The power supply device according to claim 4, characterized in that: When the second detection result is positively correlated with the first detection result, the controller controls the power supply device to limit the output of the output power. When the change in the first detection result is less than a first threshold and the change in the current flowing through the light-emitting diode is greater than a second threshold, the controller controls the power supply device to limit the output of the output power supply, wherein the second threshold is greater than the first threshold, and When the second detection result is negatively correlated with the first detection result, the controller causes the power supply device to provide the output power to the load.

6. The power supply device according to claim 1, characterized in that, The power converter includes: Synchronous rectifier switches perform synchronous rectification operations in response to the duty cycle. The second detection circuit detects the on-time of the synchronous rectifier switch, and The second detection result is the variation in the conduction time.

7. The power supply device according to claim 6, characterized in that: When the change in the first detection result is less than a first threshold and the change in the conduction time is greater than a second threshold, the controller controls the power supply device to limit the output of the output power, wherein the second threshold is greater than the first threshold. When the second detection result is negatively correlated with the first detection result, the controller controls the power supply device to limit the output of the output power, wherein the second threshold is greater than the first threshold, and When the second detection result is positively correlated with the first detection result, the controller causes the power supply device to provide the output power to the load.

8. The power supply device according to claim 1, characterized in that: The control terminal of the blocking switch is coupled to the controller. The controller activates the blocking switch to cause the power supply device to provide the output power to the load, and The controller disconnects the blocking switch to stop supplying the output power to the load.

9. The power supply device according to claim 8, characterized in that: The second detection circuit detects the on-state voltage of the blocking switch. The second detection result is the change in the conduction voltage value. When the change in the first detection result is less than a first threshold and the change in the conduction voltage value is greater than a second threshold, the controller controls the power supply device to limit the output of the output power supply, wherein the second threshold is greater than the first threshold. When the second detection result is negatively correlated with the first detection result, the controller controls the power supply device to limit the output of the output power supply, and When the second detection result is positively correlated with the first detection result, the controller causes the power supply device to provide the output power to the load.

10. The power supply device according to claim 1, characterized in that: The power supply device supplies power to the load via a communication cable conforming to the Type-C protocol. The communication cable includes a power channel, a configuration channel, and a grounding channel. The power supply device provides the output power through the power channel. The configuration channel is coupled between the configuration channel pin of the power supply device and the configuration channel pin of the load. The grounding channel is coupled between the grounding pin of the power supply device and the grounding pin of the load, and The second detection circuit detects the voltage difference between the configuration channel pin and the ground channel pin of the power converter.

11. The power supply device according to claim 10, characterized in that: The second detection result is the change in the voltage difference. When the change in the first detection result is less than a first threshold and the change in the voltage difference is greater than a second threshold, the controller controls the power supply device to limit the output of the output power, wherein the second threshold is greater than the first threshold. When the second detection result is negatively correlated with the first detection result, the controller controls the power supply device to limit the output of the output power supply, and When the second detection result is positively correlated with the first detection result, the controller causes the power supply device to provide the output power to the load.

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