Isolation DC-DC power supply for secondary side sampling and control, controller and secondary side fault processing method
By introducing a differential method of isolating channel and pulse width modulation signals into the isolated DC-DC power supply, the problem of erroneous operation in the secondary edge failure is solved, and the dual improvement of the reliability and cost of the power supply is achieved.
Patent Information
- Application Number
- CN202311790028.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-12-22
- Publication Date
- 2025-06-24
AI Technical Summary
When the existing isolated DC-DC power supply fails on the secondary side, the primary side controller is prone to enter the soft start state, resulting in power failure, and the fault treatment solution circuit is complex and costly.
By introducing an isolated channel between the secondary edge controller and the primary edge controller, the pulse width and frequency differences of the pulse width modulated signal are used to distinguish between normal and fault states, avoid misoperation, and simplify the power structure.
It realizes the power supply operation without error-starting when the secondary edge fails, simplifies the power structure, reduces costs, and improves the reliability of the power supply.
Smart Images
Figure CN120200468A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the technical field of isolated DC-DC power supplies, and more particularly to an isolated DC-DC power supply with secondary-side sampling and control, a controller, and a secondary-side fault handling method. Background Art
[0002] An isolated DC-DC (direct current to direct current) power supply is a power module that converts an input voltage into an output voltage. It uses high-frequency switching technology to convert the input voltage into a high-frequency pulse signal, then reduces or increases the voltage through a transformer, and filters out high-frequency noise through a filter circuit, finally outputting a stable DC voltage.
[0003] The power supply architectures of isolated DC-DC can be classified according to the respective functions of the primary side and the secondary side, including the following: (1) Primary-side sampling and primary-side control: Its power main switch is on the primary side, and the output voltage is sampled on the primary side to control the turn-on and turn-off of the primary-side main switch, so as to achieve the purpose of stabilizing the output; (2) Secondary-side sampling and primary-side control: Its power main switch is on the primary side, the output voltage is sampled on the secondary side, and the feedback signal is transmitted to the primary side through an isolation device, so as to control the turn-on and turn-off of the primary-side main switch, thereby achieving the purpose of stabilizing the output; (3) Secondary-side sampling and secondary-side control: Its power main switch is on the primary side, the output voltage is sampled on the secondary side, and at the same time, a control instruction for the primary-side main switch is generated on the secondary side, and the control instruction is transmitted to the primary side through an isolation device, so as to control the turn-on and turn-off of the primary-side main switch, thereby achieving the purpose of stabilizing the output.
[0004] In the above architecture (3), that is, the architecture of secondary-side sampling and secondary-side control, when a fault occurs on the secondary side, the secondary side stops sending the pulse width modulation (PWM) instruction for the primary-side main switch. At this time, the situation is equivalent to the state when the isolated DC-DC power supply is initially powered on, that is, the primary-side controller will enter soft start, which is an unwanted misoperation. In severe cases, it will cause the power supply to fail. To avoid this misoperation, the common approach to handling secondary-side faults is to send the fault signal to the primary side and let the primary side handle the secondary-side fault. Specifically, in an existing solution, the secondary-side controller transmits the instruction signal and the fault signal through different transmitting circuits, and the primary-side controller receives the instruction signal and the fault signal through different receiving circuits respectively, with complex circuits and high costs. In another existing solution, the secondary-side controller transmits the instruction signal and the fault signal through the same transmitting circuit, but the primary-side controller needs to include an identification circuit to identify and distinguish the instruction signal and the fault signal, with complex circuits and high costs. Summary of the Invention
[0005] This application is proposed to solve the above problems. According to one aspect of this application, an isolated DC-DC power supply with secondary-side sampling and control is provided. The power supply includes a primary-side controller and a secondary-side controller, and the primary-side controller and the secondary-side controller are isolated from each other through an isolation channel, where: when there is no fault on the secondary side, the secondary-side controller generates a first pulse-width modulation signal and transmits the first pulse-width modulation signal to the primary-side controller through the isolation channel; when a fault occurs on the secondary side, the secondary-side controller generates a second pulse-width modulation signal and transmits the second pulse-width modulation signal to the primary-side controller through the isolation channel; where the pulse width of the second pulse-width modulation signal is less than the pulse width of the first pulse-width modulation signal, and / or the frequency of the second pulse-width modulation signal is less than the frequency of the first pulse-width modulation signal.
[0006] In an embodiment of this application, the pulse width of the second pulse-width modulation signal is less than a preset pulse width, so that the energy of the second pulse-width modulation signal within a single pulse time is not sufficient to damage the isolated DC-DC power supply.
[0007] In an embodiment of this application, the frequency of the second pulse-width modulation signal is less than a preset frequency, so that the energy of the second pulse-width modulation signal within a continuous cycle time is not sufficient to damage the isolated DC-DC power supply.
[0008] The secondary-side controller includes an instruction signal generation circuit, a fault signal generation circuit, and a transmission circuit, and the primary-side controller includes a reception circuit, where: the instruction signal generation circuit is used to generate the first pulse-width modulation signal; the fault signal generation circuit is used to generate the second pulse-width modulation signal; the transmission circuit is used to transmit the first pulse-width modulation signal or the second pulse-width modulation signal to the reception circuit through the isolation channel.
[0009] In an embodiment of this application, after receiving the first pulse-width modulation signal, the primary-side controller drives the switching device of the primary-side controller to turn on or off based on the first pulse-width modulation signal; after receiving the second pulse-width modulation signal, the primary-side controller drives the switching device of the primary-side controller to turn on or off based on the second pulse-width modulation signal.
[0010] In an embodiment of this application, the fault includes all secondary-side faults.
[0011] According to another aspect of the present application, a controller is provided, which is applied as a secondary-side controller to an isolated DC-DC power supply for secondary-side sampling and control. The secondary-side controller includes an instruction signal generation circuit, a fault signal generation circuit, and a transmission circuit, where: when there is no fault on the secondary side, the instruction signal generation circuit generates a first pulse-width modulation signal, and the transmission circuit transmits the first pulse-width modulation signal to the primary-side controller of the power supply through an isolation channel; when a fault occurs on the secondary side, the fault signal generation circuit generates a second pulse-width modulation signal, and the transmission circuit transmits the second pulse-width modulation signal to the primary-side controller through the isolation channel; wherein, the pulse width of the second pulse-width modulation signal is less than the pulse width of the first pulse-width modulation signal, and / or, the frequency of the second pulse-width modulation signal is less than the frequency of the first pulse-width modulation signal.
[0012] In an embodiment of the present application, the pulse width of the second pulse-width modulation signal is less than a preset pulse width, so that the energy of the second pulse-width modulation signal within a single pulse time is not sufficient to damage the isolated DC-DC power supply.
[0013] In an embodiment of the present application, the frequency of the second pulse-width modulation signal is less than a preset frequency, so that the energy of the second pulse-width modulation signal within a continuous cycle time is not sufficient to damage the isolated DC-DC power supply.
[0014] In an embodiment of the present application, the fault includes all secondary-side faults.
[0015] According to still another aspect of the present application, a controller is provided, which is applied as a primary-side controller to an isolated DC-DC power supply for secondary-side sampling and control. The primary-side controller includes a receiving circuit, where: when there is no fault on the secondary side of the power supply, the receiving circuit receives a first pulse-width modulation signal from the secondary-side controller through an isolation channel, and drives the switching device of the primary-side controller to turn on or off based on the first pulse-width modulation signal; when a fault occurs on the secondary side of the power supply, the receiving circuit receives a second pulse-width modulation signal from the secondary-side controller through the isolation channel, and drives the switching device of the primary-side controller to turn on or off based on the second pulse-width modulation signal; wherein, the pulse width of the second pulse-width modulation signal is less than the pulse width of the first pulse-width modulation signal, and / or, the frequency of the second pulse-width modulation signal is less than the frequency of the first pulse-width modulation signal.
[0016] In an embodiment of the present application, the pulse width of the second pulse-width modulation signal is less than a preset pulse width, so that the energy of the second pulse-width modulation signal within a single pulse time is not sufficient to damage the isolated DC-DC power supply.
[0017] In one embodiment of the present application, the frequency of the second pulse width modulation signal is less than a preset frequency, so that the energy of the second pulse width modulation signal within a continuous cycle time is not sufficient to damage the isolated DC-DC power supply.
[0018] In one embodiment of the present application, the fault includes all secondary side faults.
[0019] According to another aspect of the present application, a fault handling method is provided, which is applied to an isolated DC-DC power supply with secondary side sampling and control. The power supply includes a primary side controller and a secondary side controller, and the primary side controller and the secondary side controller are isolated from each other through an isolation channel. The method includes: when no fault occurs on the secondary side, the secondary side controller generates a first pulse width modulation signal and transmits the first pulse width modulation signal to the primary side controller through the isolation channel; when a fault occurs on the secondary side, the secondary side controller generates a second pulse width modulation signal and transmits the second pulse width modulation signal to the primary side controller through the isolation channel; wherein, the pulse width of the second pulse width modulation signal is less than the pulse width of the first pulse width modulation signal, and / or, the frequency of the second pulse width modulation signal is less than the frequency of the first pulse width modulation signal.
[0020] In one embodiment of the present application, the pulse width of the second pulse width modulation signal is less than a preset pulse width, so that the energy of the second pulse width modulation signal within a single pulse time is not sufficient to damage the isolated DC-DC power supply.
[0021] In one embodiment of the present application, the frequency of the second pulse width modulation signal is less than a preset frequency, so that the energy of the second pulse width modulation signal within a continuous cycle time is not sufficient to damage the isolated DC-DC power supply.
[0022] In one embodiment of the present application, after receiving the first pulse width modulation signal, the primary side controller drives the switching device of the primary side controller to turn on or off based on the first pulse width modulation signal; after receiving the second pulse width modulation signal, the primary side controller drives the switching device of the primary side controller to turn on or off based on the second pulse width modulation signal.
[0023] For the isolated DC-DC power supply with secondary side sampling and control of the present application, regardless of whether a fault occurs on the secondary side, the secondary side controller transmits a pulse width modulation signal to the primary side controller. Only the second pulse width modulation signal in the fault state is a safe and special pulse width modulation signal. This enables the secondary side controller to not require multiple transmitting circuits to distinguish and transmit command signals and fault signals, and the primary side controller to not require multiple receiving circuits to distinguish and receive command signals and fault signals, nor to require an identification circuit to distinguish command signals and fault signals. Thus, the overall structure of the isolated DC-DC power supply with secondary side sampling and control is simplified, and the cost is reduced. Description of the Drawings
[0024] The above and other objects, features, and advantages of the present application will become more apparent by describing the embodiments of the present application in more detail in conjunction with the accompanying drawings. The accompanying drawings are used to provide a further understanding of the embodiments of the present application and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the present application and do not constitute a limitation to the present application. In the accompanying drawings, the same reference numerals generally represent the same components or steps.
[0025] Figure 1 FIG. shows a schematic architecture diagram of an example of a secondary-side sampling and control isolated DC-DC power supply with an existing solution.
[0026] Figure 2 FIG. shows a schematic architecture diagram of an example of a secondary-side sampling and control isolated DC-DC power supply with an existing solution.
[0027] Figure 3 FIG. shows a schematic architecture diagram of a secondary-side sampling and control isolated DC-DC power supply according to an embodiment of the present application.
[0028] Figure 4 FIG. shows a more specific schematic architecture diagram of a secondary-side sampling and control isolated DC-DC power supply according to an embodiment of the present application.
[0029] Figure 5 FIG. shows a schematic flowchart of a fault handling method according to an embodiment of the present application.
[0030] Figure 6 FIG. shows a schematic structural block diagram of a secondary-side controller according to an embodiment of the present application.
[0031] Figure 7 FIG. shows a schematic structural block diagram of a primary-side controller according to an embodiment of the present application. Detailed Description of the Embodiments
[0032] In order to make the objectives, technical solutions, and advantages of the present application more apparent, the exemplary embodiments according to the present application will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments of the present application. It should be understood that the present application is not limited by the exemplary embodiments described herein. Based on the embodiments of the present application described in the present application, all other embodiments obtained by those skilled in the art without creative efforts shall fall within the protection scope of the present application.
[0033] Figure 1 FIG. shows a schematic architecture diagram of an example of a secondary-side sampling and control isolated DC-DC power supply 100 with an existing solution. As Figure 1As shown in the figure, the secondary-side sampling and control (i.e., secondary-side sampling and secondary-side control) isolated DC-DC power supply 100 includes a primary-side controller and a secondary-side controller. Among them, the secondary-side controller includes an instruction signal generation circuit, a fault signal generation circuit, transmission circuit 1, and transmission circuit 2; the primary-side controller includes reception circuit 1 and reception circuit 2. Among them, when there is no fault on the secondary side, the instruction signal generation circuit generates a pulse width modulation signal. This pulse width modulation signal obtains signal S1 through transmission circuit 1, and then obtains signal S1' through isolation channel 1 and transmits it to reception circuit 1. Reception circuit 1 controls the switching device of the primary-side controller to turn on or off according to this instruction signal. When a fault occurs on the secondary side, the fault signal generation circuit generates a fault signal (usually an amplitude modulation signal or a frequency modulation signal). This fault signal obtains signal S2 through transmission circuit 2, and then obtains signal S2' through isolation channel 2 and transmits it to reception circuit 2. Reception circuit 2 controls the switching device of the primary-side controller to turn off according to this fault signal. The secondary-side controller of this power supply includes two transmission circuits, and the primary-side controller includes two reception circuits, with complex circuitry and high costs.
[0034] Figure 2 The architecture diagram of another example of the secondary-side sampling and control isolated DC-DC power supply 200 of the existing solution is shown. As Figure 2 shown, the secondary-side sampling and control (i.e., secondary-side sampling and secondary-side control) isolated DC-DC power supply 200 includes a primary-side controller and a secondary-side controller. Among them, the secondary-side controller includes an instruction signal generation circuit, a fault signal generation circuit, and a transmission circuit; the primary-side controller includes a reception circuit and an identification circuit. Among them, when there is no fault on the secondary side, the instruction signal generation circuit generates a pulse width modulation signal. This pulse width modulation signal obtains signal S1 through the transmission circuit, and then obtains signal S1' through the isolation channel and transmits it to the reception circuit. The reception circuit then transmits it to the identification circuit. The identification circuit identifies that this signal is an instruction signal rather than a fault signal, and controls the switching device of the primary-side controller to turn on or off according to this instruction signal. When a fault occurs on the secondary side, the fault signal generation circuit generates a fault signal (usually an amplitude modulation signal or a frequency modulation signal, such as a fault request pulse of 110 kHz (lasting for 82 ms)). This fault signal obtains signal S1 through the transmission circuit, and then obtains signal S1' through the isolation channel and transmits it to the reception circuit. The reception circuit then transmits it to the identification circuit. The identification circuit identifies that this signal is a fault signal rather than an instruction signal. The reception circuit controls the switching device of the primary-side controller to turn off according to this fault signal. The primary-side controller of this power supply includes a reception circuit and an identification circuit, and the identification circuit also requires a timer, with complex circuitry.
[0035] Based on the above problems, the present application provides a new solution that can achieve a simpler and lower-cost processing solution. The following will be described in conjunction with Figures 3 to 7 this.
[0036] Figure 3 The figure shows a schematic architecture diagram of a secondary-side sampling and control isolated DC-DC power supply 300 according to an embodiment of the present application. As Figure 3 shown, the secondary-side sampling and control isolated DC-DC power supply 300 includes a primary controller 310 and a secondary controller 320, and the primary controller 310 and the secondary controller 320 are isolated from each other through an isolation channel, where: when there is no fault on the secondary side, the secondary controller 320 generates a first pulse width modulation signal and transmits the first pulse width modulation signal to the primary controller 310 through the isolation channel; when a fault occurs on the secondary side, the secondary controller 320 generates a second pulse width modulation signal and transmits the second pulse width modulation signal to the primary controller 310 through the isolation channel; wherein, the pulse width of the second pulse width modulation signal is less than the pulse width of the first pulse width modulation signal, and / or, the frequency of the second pulse width modulation signal is less than the frequency of the first pulse width modulation signal.
[0037] In an embodiment of the present application, regardless of whether a fault occurs on the secondary side, the signal transmitted by the secondary controller 320 to the primary controller 310 is a pulse width modulation signal. Only the second pulse width modulation signal in the fault state is usually narrower in pulse width and lower in frequency than the first pulse width modulation signal in the normal state. After receiving the second pulse width modulation signal, the primary controller 310 has no difference from receiving the first pulse width modulation signal, and both are used as switch drive signals. Specifically, after receiving the second pulse width modulation signal, the primary controller 310 can control its switching device to turn on or off. After the fault of the secondary controller 320 is eliminated, it can continue to operate normally (transmit the first pulse width modulation signal). Since the second pulse width modulation signal is usually narrower in pulse width and / or lower in frequency than the first pulse width modulation signal, it can avoid the pulse energy from causing the entire structural system to be in an over-stress state and ensure the reliability of the entire power supply system.
[0038] In one example, the pulse width of the second pulse width modulation signal is less than a preset pulse width, so that the energy of the second pulse width modulation signal within a single pulse time is not sufficient to damage the power supply. In this example, the pulse width of the second pulse width modulation signal can be specified to be less than a preset threshold to ensure that the energy within a single pulse time will not damage the power supply, and this preset threshold can be set according to the specific situation of the device.
[0039] In one example, the frequency of the second pulse width modulation signal is less than a preset frequency, so that the energy of the second pulse width modulation signal within a continuous cycle time is not sufficient to damage the power supply. In this example, the frequency of the second pulse width modulation signal can be specified to be less than a preset threshold to ensure that the energy of the pulse signal within several continuous cycle times will not damage the power supply, and this preset threshold can be set according to the specific situation of the device.
[0040] In the embodiments of the present application, regardless of whether a fault occurs on the secondary side, the secondary side controller 320 transmits a pulse width modulation signal to the primary side controller 310. The primary side controller 310 does not need multiple receiving circuits to separately receive the first pulse width modulation signal and the second pulse width modulation signal, nor does it need to distinguish the first pulse width modulation signal and the second pulse width modulation signal through an identification circuit. Instead, it can drive the switch based on the pulse width modulation signal of the same type as the instruction signal, which can simplify the structure of the primary side controller 310. On the other hand, the secondary side controller 320 also does not need multiple transmitting circuits to separately transmit the first pulse width modulation signal and the second pulse width modulation signal, thereby making the overall structure of the secondary side sampling and controlled isolated DC-DC power supply 300 simpler and the cost lower. The following will be described in conjunction with Figure 4 for description.
[0041] Figure 4 FIG. shows a more specific architecture schematic diagram of the secondary side sampling and controlled isolated DC-DC power supply 300 according to an embodiment of the present application. As Figure 4 shown, the secondary side sampling and controlled isolated DC-DC power supply 300 includes a primary side controller 310 and a secondary side controller 320, and the primary side controller 310 and the secondary side controller 320 are isolated from each other through an isolation channel. Among them, the secondary side controller 320 includes an instruction signal generation circuit, a fault signal generation circuit, and a transmitting circuit, and the primary side controller 310 includes a receiving circuit, where: the instruction signal generation circuit is used to generate a first pulse width modulation signal; the fault signal generation circuit is used to generate a second pulse width modulation signal. The transmitting circuit is used to transmit the first pulse width modulation signal or the second pulse width modulation signal to the receiving circuit through the isolation channel.
[0042] In this embodiment, when no fault occurs on the secondary side, the instruction signal generation circuit of the secondary side controller 320 generates a first pulse width modulation signal, and the transmitting circuit of the secondary side controller 320 transmits the first pulse width modulation signal to the receiving circuit of the primary side controller 310 through the isolation channel; when a fault occurs on the secondary side, the fault signal generation circuit of the secondary side controller 320 generates a second pulse width modulation signal, and the transmitting circuit transmits the second pulse width modulation signal to the receiving circuit of the primary side controller 310 through the isolation channel; where the pulse width of the second pulse width modulation signal is less than the pulse width of the first pulse width modulation signal, and / or the frequency of the second pulse width modulation signal is less than the frequency of the first pulse width modulation signal.
[0043] Generally, both the command signal and the fault signal are a series of undifferentiated pulse width modulation signals. When processing the secondary fault signal, essentially the fault signal is converted into a safe pulse width modulation command signal, and then through the transmission circuit of the secondary controller 320, the isolation communication channel, and the receiving circuit of the primary controller 310, the fault signal generated by the secondary controller 320 is transmitted to the primary controller 310. After being processed by the receiving circuit in the primary controller 310, it serves as the drive command signal for the main switch of the primary controller 310 to drive the switch to turn on or off to cope with the secondary fault. This solution does not require, like other solutions, either a dedicated transmission circuit and receiving circuit for the secondary fault signal; or a distinguishing circuit needs to be set on the primary side to distinguish and identify the command signal and the fault signal and then make corresponding processing. In addition, because the secondary controller 320 is in a fault state, it is necessary to limit the pulse signal width and frequency (as described above, the second pulse width modulation signal is generally narrower in pulse width and lower in frequency than the first pulse width modulation signal, less than a preset threshold, etc.), which can ensure that the pulse energy output by the primary controller 310 does not cause the system to be in an over-stress state and ensure the reliability of the power supply.
[0044] Compare Figure 4 with Figure 1 it can be seen that in the solution of this application, the primary controller 310 does not require two receiving circuits, the secondary controller 320 does not require two transmission circuits, nor two isolation channels, which simplifies the architecture of the entire power supply 300 and reduces the cost. Compare Figure 4 with Figure 2 it can be seen that in the solution of this application, the primary controller 310 does not require an identification circuit to identify the command signal and the fault signal, and thus the timer for the identification circuit is also omitted, which greatly simplifies the primary controller 310, simplifies the circuit, and reduces the cost.
[0045] It should be noted that in the embodiments of this application, the faults occurring on the secondary side described above mainly refer to faults such as overvoltage, undervoltage of the output voltage, overcurrent of the current, short circuit, open circuit of the output, etc., which mainly refer to energy-related faults. The aforementioned faults may also include over-temperature faults, etc. The over-temperature protection (OTP) for them may also be the OTP of the output power transistor or the OTP of the output controller. Generally, it is defaulted that the logic circuit of the fault management unit (not shown in the figure) of the secondary controller 320 is still normally powered, otherwise the secondary controller 320 will not be able to send any signal to the primary controller 310. At that time, the primary controller 310 determines that the power supply of the secondary controller is abnormal by not receiving the feedback signal from the secondary controller 320 for a period of time, and thus takes over the control and starts soft start.
[0046] The isolated DC-DC power supply 300 with secondary side sampling and control according to an embodiment of the present application is exemplarily shown above. Based on the above description, for the isolated DC-DC power supply 300 with secondary side sampling and control according to an embodiment of the present application, regardless of whether a fault occurs on the secondary side, the pulse width modulation signal transmitted by the secondary side controller to the primary side controller is a pulse width modulation signal. Only the pulse width modulation signal in the case of a secondary side fault is a safe and special pulse width modulation signal. This enables the secondary side controller to eliminate the need for multiple transmitting circuits to distinguish between transmitting the first pulse width modulation signal and the second pulse width modulation signal, and the primary side controller to eliminate the need for multiple receiving circuits to distinguish between receiving the command signal and the fault signal, and also eliminates the need for an identification circuit to distinguish between the command signal and the fault signal, thereby simplifying the overall structure of the isolated DC-DC power supply with secondary side sampling and control and reducing costs.
[0047] The following Figure 5 describes a schematic flowchart of a fault handling method 500 according to an embodiment of the present application. It is a secondary side fault handling method and can be executed by the isolated DC-DC power supply 300 with secondary side sampling and control according to an embodiment of the present application described above. Since the structure and specific operations of the isolated DC-DC power supply 300 with secondary side sampling and control according to an embodiment of the present application have been described in detail above, for the sake of brevity, only a brief description of the fault handling method 500 executed by it will be given here.
[0048] As Figure 5 shown, the fault handling method 500 according to an embodiment of the present application may include the following steps:
[0049] In step S510, when no fault occurs on the secondary side, the secondary side controller generates a first pulse width modulation signal and transmits the first pulse width modulation signal to the primary side controller through an isolation channel.
[0050] In step S520, when a fault occurs on the secondary side, the secondary side controller generates a second pulse width modulation signal and transmits the second pulse width modulation signal to the primary side controller through an isolation channel; wherein, the pulse width of the second pulse width modulation signal is generally less than the pulse width of the first pulse width modulation signal, and / or the frequency of the second pulse width modulation signal is generally less than the frequency of the first pulse width modulation signal.
[0051] In an embodiment of the present application, in the fault handling method 500 for secondary side faults, regardless of whether a fault occurs on the secondary side, the signal transmitted by the secondary side controller to the primary side controller is a pulse width modulation signal. Only the second pulse width modulation signal in the fault state is generally narrower in pulse width and lower in frequency than the first pulse width modulation signal in the normal state. After receiving the second pulse width modulation signal, the primary side controller has no difference from receiving the first pulse width modulation signal, and both are used as switch drive signals. Specifically, after receiving the second pulse width modulation signal, the primary side controller can control its switching device to turn on or off. After the fault of the secondary side controller is eliminated, it can continue to operate normally (transmitting the first pulse width modulation signal). Since the second pulse width modulation signal is generally narrower in pulse width and / or lower in frequency than the first pulse width modulation signal, it can avoid the pulse energy from causing the entire structural system to be in an over-stress state and ensure the reliability of the entire power supply system.
[0052] In one example, the pulse width of the second pulse width modulation signal is less than a preset pulse width, so that the energy of the second pulse width modulation signal within a single pulse time is not sufficient to damage the power supply. In this example, the pulse width of the second pulse width modulation signal can be specified to be less than a preset threshold to ensure that the energy within a single pulse time will not damage the power supply, and this preset threshold can be set according to the specific situation of the device.
[0053] In one example, the frequency of the second pulse width modulation signal is less than a preset frequency, so that the energy of the second pulse width modulation signal within a continuous cycle time is not sufficient to damage the power supply. In this example, the frequency of the second pulse width modulation signal can be specified to be less than a preset threshold to ensure that the energy of the pulse signal within several continuous cycle times will not damage the power supply, and this preset threshold can be set according to the specific situation of the device.
[0054] In an embodiment of the present application, regardless of whether a fault occurs on the secondary side, the signal transmitted by the secondary side controller to the primary side controller is a pulse width modulation signal. The primary side controller does not need multiple receiving circuits to distinguish and receive the first pulse width modulation signal and the second pulse width modulation signal, nor does it need to distinguish the first pulse width modulation signal and the second pulse width modulation signal through an identification circuit. Instead, it can drive the switch based on a pulse width modulation signal of the same type as the command signal, which can simplify the structure of the primary side controller. On the other hand, the secondary side controller also does not need multiple transmitting circuits to distinguish and transmit the first pulse width modulation signal and the second pulse width modulation signal, thus making the overall structure of the secondary side sampling and controlled isolated DC-DC power supply simpler and lower in cost.
[0055] In the embodiments of the present application, the faults occurring on the secondary side described above mainly refer to faults such as overvoltage, undervoltage of the output voltage, overcurrent of the current, short circuit, output open circuit, etc. These mainly refer to faults in terms of energy. The aforementioned faults may also include over-temperature faults, etc. The over-temperature protection (OTP) faults for them can also be the OTP of the output power transistor or the OTP of the output controller. Generally, it is default that the logic circuit of the fault management unit (not shown in the figure) of the secondary side controller is still normally powered. Otherwise, the secondary side controller will not be able to send any signal to the primary side controller. At that time, the primary side controller determines that the power supply of the secondary side controller is abnormal by not receiving the feedback signal from the secondary side controller within a period of time, and thus takes over the control to start soft start.
[0056] The fault handling method 500 according to the embodiments of the present application is exemplarily shown above. Based on the above description, in the fault handling method 500 according to the embodiments of the present application, regardless of whether a fault occurs on the secondary side, the pulse width modulation signal transmitted by the secondary side controller to the primary side controller is a pulse width modulation signal. Only the pulse width modulation signal in the case of a secondary side fault is a safe and special pulse width modulation signal. This enables the secondary side controller to not require multiple transmitting circuits to distinguish and transmit the first pulse width modulation signal and the second pulse width modulation signal, and the primary side controller to not require multiple receiving circuits to distinguish and receive the instruction signal and the fault signal, nor to distinguish the instruction signal and the fault signal through an identification circuit, thereby simplifying the overall structure of the secondary side sampling and control isolated DC-DC power supply and reducing costs.
[0057] The following combines Figure 6 Describe the controller 600 according to the embodiments of the present application. This controller 600 is applied as the secondary side controller to the isolated DC-DC power supply 300 for secondary side sampling and control, and has the same structure as the secondary side controller 320 in the isolated DC-DC power supply 300 for secondary side sampling and control according to the embodiments of the present application. Since the structure and specific operations of the secondary side controller 320 in the isolated DC-DC power supply 300 for secondary side sampling and control according to the embodiments of the present application have been described in detail above, for the sake of brevity, only a brief description is given here for the secondary side controller 600.
[0058] As Figure 6As shown, the secondary side controller 600 includes an instruction signal generation circuit 610, a fault signal generation circuit 620, and a transmission circuit 630, where: when there is no fault on the secondary side, the instruction signal generation circuit 610 generates a first pulse width modulation signal, and the transmission circuit 630 transmits the first pulse width modulation signal to the primary side controller of the power supply through an isolation channel; when a fault occurs on the secondary side, the fault signal generation circuit 620 generates a second pulse width modulation signal, and the transmission circuit 630 transmits the second pulse width modulation signal to the primary side controller through an isolation channel; where the pulse width of the second pulse width modulation signal is generally less than the pulse width of the first pulse width modulation signal, and / or the frequency of the second pulse width modulation signal is generally less than the frequency of the first pulse width modulation signal.
[0059] In an embodiment of the present application, whether the instruction signal or the fault signal sent by the secondary side controller 600 to the primary side controller is a series of pulse width modulation signals. In this way, when processing the secondary side fault signal, the secondary side controller 600 only needs to process the fault signal as a special pulse width modulation instruction signal, and such processing will become simple - essentially, the fault signal generation circuit 620 generates the fault signal as a kind of pulse width modulation instruction signal, and then it is transmitted to the primary side controller through the transmission circuit 630 and the isolation communication channel of the secondary side controller 600. After being processed by the receiving circuit in the primary side controller, it is used as the driving instruction signal of the primary side controller main switch to drive the switch to turn on or off to cope with the secondary side fault. In addition, because the secondary side is in a fault state, it is necessary to limit the width and frequency of the fault pulse signal (as described above, the second pulse width modulation signal is generally narrower and lower in frequency than the first pulse width modulation signal, less than a preset threshold, etc.), which can ensure that the pulse energy output by the primary side controller will not cause the system to be in an over-stress state and ensure the reliability of the power supply.
[0060] In one example, the pulse width of the second pulse width modulation signal is less than a preset pulse width, so that the energy of the second pulse width modulation signal within a single pulse time is not sufficient to damage the power supply. In this example, the pulse width of the second pulse width modulation signal can be specified to be less than a preset threshold to ensure that the energy within a single pulse time will not damage the power supply, and this preset threshold can be set according to the specific situation of the device.
[0061] In one example, the frequency of the second pulse width modulation signal is less than a preset frequency, so that the energy of the second pulse width modulation signal within a continuous cycle time is not sufficient to damage the power supply. In this example, the frequency of the second pulse width modulation signal can be specified to be less than a preset threshold to ensure that the energy of the pulse signal within a number of continuous cycle times will not damage the power supply, and this preset threshold can be set according to the specific situation of the device.
[0062] In an embodiment of the present application, the faults that occur in the aforementioned secondary controller 600 mainly refer to faults such as overvoltage, undervoltage of the output voltage, overcurrent of the current, short circuit, open circuit of the output, etc. These mainly refer to faults in terms of energy. The aforementioned faults may also include over-temperature faults, etc. The over-temperature protection (OTP) faults for them can also be the OTP of the output power transistor or the OTP of the output controller. Generally, it is default that the logic circuit of the fault management unit (not shown in the figure) of the secondary controller 600 is still powered normally. Otherwise, the secondary controller 600 will not be able to send any signal to the primary controller. At that time, the primary controller determines that the power supply of the secondary controller is abnormal by not receiving the feedback signal of the secondary controller 600 within a period of time, and thus takes over the control to start soft start.
[0063] Based on the above description, for the secondary controller according to the embodiment of the present application, whether a fault occurs on the secondary side or not, the secondary controller transmits a pulse width modulation signal to the primary controller. It's just that the pulse width modulation signal in the case of a secondary fault is a safe and special pulse width modulation signal. This enables the secondary controller not to require multiple transmitting circuits to distinguish and transmit the first pulse width modulation signal and the second pulse width modulation signal, and the primary controller does not require multiple receiving circuits to distinguish and receive the command signal and the fault signal, nor does it need to distinguish the command signal and the fault signal through an identification circuit, thereby simplifying the overall structure of the secondary sampling and control isolated DC-DC power supply and reducing costs.
[0064] The following combines Figure 7 Describe the controller 700 according to the embodiment of the present application. This controller 700 is applied as the primary controller to the isolated DC-DC power supply 300 for secondary sampling and control, and has the same structure as the primary controller 310 in the isolated DC-DC power supply 300 for secondary sampling and control according to the embodiment of the present application. Since the structure and specific operations of the primary controller 310 in the isolated DC-DC power supply 300 for secondary sampling and control according to the embodiment of the present application have been described in detail above, for the sake of brevity, the primary controller 700 will only be briefly described here.
[0065] As Figure 7 shown, the primary controller 700 includes a receiving circuit 710. When no fault occurs on the secondary side of the power supply, the receiving circuit 710 receives the first pulse width modulation signal from the secondary controller through the isolation channel and drives the switching device of the primary controller 700 to turn on or off based on the first pulse width modulation signal; when a fault occurs on the secondary side of the power supply, the receiving circuit 710 receives the second pulse width modulation signal from the secondary controller through the isolation channel and drives the switching device of the primary controller 700 to turn on or off based on the second pulse width modulation signal; wherein, the pulse width of the second pulse width modulation signal is usually less than the pulse width of the first pulse width modulation signal, and / or, the frequency of the second pulse width modulation signal is usually less than the frequency of the first pulse width modulation signal.
[0066] In an embodiment of the present application, whether the instruction signal or the fault signal received by the primary controller 700 from the secondary controller is a series of pulse width modulation signals. In this way, when receiving a signal from the secondary controller, the processed signal is always a pulse width modulation signal, which simplifies the processing. This is because when the secondary controller is in a fault state, the pulse width and frequency of the pulse width modulation signal received from it are restricted compared to those received in a non-fault state (as described above, the second pulse width modulation signal is usually narrower in pulse width and lower in frequency than the first pulse width modulation signal, and is less than a preset threshold, etc.). After being processed by the receiving circuit 710, the pulse width modulation signal serves as the drive instruction signal for the main switch of the primary controller 700 to drive the switch to turn on or off to cope with the secondary fault. Since there is no need to distinguish between the fault signal and the instruction signal, the structure of the primary controller 700 is simplified, eliminating the need for two receiving circuits 710 and an identification circuit, thus reducing costs.
[0067] In one example, the pulse width of the second pulse width modulation signal is less than a preset pulse width, such that the energy of the second pulse width modulation signal within a single pulse time is not sufficient to damage the power supply. In this example, the pulse width of the second pulse width modulation signal can be specified to be less than a preset threshold to ensure that the energy within a single pulse time will not damage the power supply, and this preset threshold can be set according to the specific situation of the device.
[0068] In one example, the frequency of the second pulse width modulation signal is less than a preset frequency, such that the energy of the second pulse width modulation signal within a continuous cycle time is not sufficient to damage the power supply. In this example, the frequency of the second pulse width modulation signal can be specified to be less than a preset threshold to ensure that the energy of the pulse signal within a number of continuous cycle times will not damage the power supply, and this preset threshold can be set according to the specific situation of the device.
[0069] In an embodiment of the present application, the faults that occur in the aforementioned secondary controller mainly refer to faults such as overvoltage, undervoltage of the output voltage, overcurrent of the current, short circuit, open circuit of the output, etc., which are mainly energy-related faults. The aforementioned faults may also include over-temperature faults, etc. The over-temperature protection (OTP) faults for these can be the OTP of the output power transistor or the OTP of the output controller. Generally, it is defaulted that the logic circuit of the fault management unit (not shown in the figure) of the secondary controller is still normally powered, otherwise the secondary controller will not be able to send any signal to the primary controller 700. At that time, the primary controller 700 determines that the power supply of the secondary controller is abnormal due to not receiving the feedback signal from the secondary controller for a period of time, and thus takes over the control to start soft start.
[0070] Based on the above description, whether the instruction signal or the fault signal received by the primary side controller 700 according to the embodiments of the present application from the secondary side controller is a pulse width modulation signal. Only the pulse width modulation signal as the fault signal is a safe and special pulse width modulation signal. This enables the primary side controller to not require multiple receiving circuits to separately receive the instruction signal and the fault signal, nor to require an identification circuit to distinguish between the instruction signal and the fault signal, thereby simplifying the overall structure of the secondary side sampling and control isolated DC-DC power supply and reducing costs.
[0071] Although example embodiments have been described herein with reference to the accompanying drawings, it should be understood that the above example embodiments are merely exemplary and are not intended to limit the scope of the present application thereto. Those of ordinary skill in the art can make various changes and modifications therein without departing from the scope and spirit of the present application. All such changes and modifications are intended to be included within the scope of the present application as claimed in the appended claims.
[0072] Those of ordinary skill in the art can realize that the units and algorithm steps of the examples described in conjunction with the embodiments disclosed herein can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are executed in a hardware or software manner depends on the specific application and design constraints of the technical solution. Professional technicians can use different methods for each specific application to implement the described functions, but such implementation should not be considered to exceed the scope of the present application.
[0073] In several embodiments provided by the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the units is only a logical function division, and there may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another device, or some features can be ignored or not executed.
[0074] In the specification provided herein, a large number of specific details are set forth. However, it can be understood that the embodiments of the present application can be practiced without these specific details. In some instances, well-known methods, structures, and technologies have not been shown in detail so as not to obscure the understanding of this specification.
[0075] Similarly, it should be understood that, for the purpose of streamlining the present application and facilitating the understanding of one or more of the various inventive aspects, in the description of the exemplary embodiments of the present application, the various features of the present application are sometimes grouped together into a single embodiment, figure, or description thereof. However, the methods of the present application should not be construed as reflecting an intention that the claimed present application requires more features than those expressly recited in each claim. Rather, as reflected by the corresponding claims, the inventive point lies in that the corresponding technical problems can be solved by features less than all the features of a single disclosed embodiment. Therefore, the claims following the detailed description are hereby expressly incorporated into the detailed description, where each claim itself serves as a separate embodiment of the present application.
[0076] Those skilled in the art can understand that, except for features that are mutually exclusive, any combination can be adopted for all the features disclosed in this specification (including the accompanying claims, abstract, and drawings) and all the processes or units of any method or device thus disclosed. Unless otherwise expressly stated, each feature disclosed in this specification (including the accompanying claims, abstract, and drawings) can be replaced by an alternative feature that provides the same, equivalent, or similar purpose.
[0077] In addition, those skilled in the art can understand that, although some of the embodiments described herein include certain features included in other embodiments rather than other features, the combination of the features of different embodiments means that it is within the scope of the present application and forms different embodiments. For example, in the claims, any one of the claimed embodiments can be used in any combination.
[0078] The various component embodiments of the present application can be implemented in hardware, or in software modules running on one or more processors, or in a combination thereof. Those skilled in the art should understand that a microprocessor or a digital signal processor (DSP) can be used in practice to implement some or all of the functions of some of the modules according to the embodiments of the present application. The present application can also be implemented as a plug-in program (for example, a computer program and a computer program product) for executing part or all of the methods described herein. Such a program for implementing the present application can be stored on a computer-readable medium, or can be in the form of one or more signals. Such signals can be downloaded from an Internet website, or provided on a carrier signal, or provided in any other form.
[0079] It should be noted that the above embodiments are illustrative of the present application rather than restrictive of the present application, and those skilled in the art can design alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word "comprising" does not exclude the presence of elements or steps not listed in the claim. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The present application can be implemented by means of hardware including several different elements and by means of a suitably programmed computer. In the unit claims listing several power strips, several of these power strips may be embodied by the same hardware item. The use of the words first, second, and third, etc. does not denote any order. These words may be interpreted as names.
[0080] As described above, the above is only the specific implementation manner or the description of the specific implementation manner of the present application, and the protection scope of the present application is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present application can easily think of changes or substitutions, which should all be covered within the protection scope of the present application. The protection scope of the present application shall be subject to the protection scope of the claims.
Claims
1. An isolated DC-DC power supply with secondary side sampling and control, characterized in that, The power supply includes a primary controller and a secondary controller, which are isolated from each other through an isolation channel, where: When no fault occurs on the secondary side, the secondary controller generates a first pulse width modulation signal and transmits the first pulse width modulation signal to the primary controller through the isolation channel; When a fault occurs on the secondary side, the secondary controller generates a second pulse width modulation signal and transmits the second pulse width modulation signal to the primary controller through the isolation channel; Wherein, the pulse width of the second pulse width modulation signal is less than the pulse width of the first pulse width modulation signal, and / or the frequency of the second pulse width modulation signal is less than the frequency of the first pulse width modulation signal.
2. The power supply according to claim 1, characterized in that, The pulse width of the second pulse width modulation signal is less than a preset pulse width, so that the energy of the second pulse width modulation signal within a single pulse time is not sufficient to damage the isolated DC-DC power supply.
3. The power supply according to claim 1, wherein The frequency of the second pulse width modulation signal is less than a preset frequency, so that the energy of the second pulse width modulation signal within a continuous cycle time is not sufficient to damage the isolated DC-DC power supply.
4. The power supply according to any one of claims 1 to 3, characterized in that The secondary controller includes an instruction signal generation circuit, a fault signal generation circuit and a transmission circuit, and the primary controller includes a reception circuit, where: The instruction signal generation circuit is used to generate the first pulse width modulation signal; The fault signal generation circuit is used to generate the second pulse width modulation signal; The transmission circuit is used to transmit the first pulse width modulation signal or the second pulse width modulation signal to the reception circuit through the isolation channel.
5. The power supply according to any one of claims 1-3, wherein After receiving the first pulse width modulation signal, the primary controller drives the switching device of the primary controller to turn on or off based on the first pulse width modulation signal; After receiving the second pulse width modulation signal, the primary controller drives the switching device of the primary controller to turn on or off based on the second pulse width modulation signal.
6. The power supply according to any one of claims 1-3, characterized in that, The fault includes all secondary side faults.
7. A controller, which is applied as a secondary side controller to an isolated DC-DC power supply for secondary side sampling and control, is characterized in that The secondary controller includes an instruction signal generation circuit, a fault signal generation circuit and a transmission circuit, where: When no fault occurs on the secondary side, the instruction signal generation circuit generates a first pulse width modulation signal, and the transmission circuit transmits the first pulse width modulation signal to the primary controller of the power supply through the isolation channel; When a fault occurs on the secondary side, the fault signal generation circuit generates a second pulse width modulation signal, and the transmission circuit transmits the second pulse width modulation signal to the primary controller through the isolation channel; Wherein, the pulse width of the second pulse width modulation signal is less than the pulse width of the first pulse width modulation signal, and / or the frequency of the second pulse width modulation signal is less than the frequency of the first pulse width modulation signal.
8. The controller according to claim 7, characterized in that The pulse width of the second pulse width modulation signal is less than a preset pulse width, so that the energy of the second pulse width modulation signal within a single pulse time is not sufficient to damage the isolated DC-DC power supply.
9. The controller according to claim 7, wherein The frequency of the second pulse-width modulation signal is less than a preset frequency, such that the energy of the second pulse-width modulation signal within a continuous cycle time is not sufficient to damage the isolated DC-DC power supply.
10. The controller according to any one of claims 7-9, characterized in that, The faults include all secondary-side faults.
11. A controller, which is applied as a primary-side controller to an isolated DC-DC power supply with secondary-side sampling and control, is characterized in that The primary-side controller includes a receiving circuit, wherein: When no fault occurs on the secondary side of the power supply, the receiving circuit receives a first pulse-width modulation signal from the secondary-side controller through an isolation channel, and drives the switching device of the primary-side controller to turn on or off based on the first pulse-width modulation signal; When a fault occurs on the secondary side of the power supply, the receiving circuit receives a second pulse-width modulation signal from the secondary-side controller through the isolation channel, and drives the switching device of the primary-side controller to turn on or off based on the second pulse-width modulation signal; wherein, the pulse width of the second pulse-width modulation signal is less than the pulse width of the first pulse-width modulation signal, and / or, the frequency of the second pulse-width modulation signal is less than the frequency of the first pulse-width modulation signal.
12. The controller according to claim 11, wherein The pulse width of the second pulse-width modulation signal is less than a preset pulse width, such that the energy of the second pulse-width modulation signal within a single pulse time is not sufficient to damage the isolated DC-DC power supply.
13. The controller according to claim 11, wherein The frequency of the second pulse-width modulation signal is less than a preset frequency, such that the energy of the second pulse-width modulation signal within a continuous cycle time is not sufficient to damage the isolated DC-DC power supply.
14. The controller according to any one of claims 11-13, characterized in that, The faults include all secondary-side faults.
15. A fault handling method, applied to an isolated DC-DC power supply with secondary side sampling and control, the power supply including a primary side controller and a secondary side controller, where the primary side controller and the secondary side controller are isolated from each other through an isolation channel, characterized in that, The method includes: When no fault occurs on the secondary side, the secondary-side controller generates a first pulse-width modulation signal, and transmits the first pulse-width modulation signal to the primary-side controller through the isolation channel; When a fault occurs on the secondary side, the secondary-side controller generates a second pulse-width modulation signal, and transmits the second pulse-width modulation signal to the primary-side controller through the isolation channel; wherein, the pulse width of the second pulse-width modulation signal is less than the pulse width of the first pulse-width modulation signal, and / or, the frequency of the second pulse-width modulation signal is less than the frequency of the first pulse-width modulation signal.
16. The method according to claim 15, characterized in that, The pulse width of the second pulse-width modulation signal is less than a preset pulse width, such that the energy of the second pulse-width modulation signal within a single pulse time is not sufficient to damage the isolated DC-DC power supply.
17. The method according to claim 15, wherein The frequency of the second pulse-width modulation signal is less than a preset frequency, such that the energy of the second pulse-width modulation signal within a continuous cycle time is not sufficient to damage the isolated DC-DC power supply.
18. The method according to any one of claims 15-17, wherein after receiving the first pulse-width modulation signal, the primary-side controller drives the switching device of the primary-side controller to turn on or off based on the first pulse-width modulation signal; after receiving the second pulse-width modulation signal, the primary-side controller drives the switching device of the primary-side controller to turn on or off based on the second pulse-width modulation signal.