A power-down control method and device, a storage medium and an image signal generator

Abstract

The application discloses a power-off control method and device, a storage medium and an image signal generator, and applies to the technical field of circuits. The method comprises the following steps: when a power-off operation is performed, first, discharging is performed through a preset discharging circuit, and based on a power-off time, the output voltage of an adjustable power supply is gradually reduced. When the output voltage value of the adjustable power supply is a preset voltage value, the adjustable power supply is turned off, and discharging is continuously performed through the preset discharging circuit, so that the final power-off of the output end of the adjustable power supply is realized. In this way, the stored charges on the parallel capacitor are released through a secondary power-off process control when the power supply is powered off. Since the preset discharging circuit discharges quickly, the capacitor can be completely flashed in 1 ms. Therefore, the power-off of the power supply can be accurately controlled based on the power-off time.

Description

Technical Field

[0001] This application relates to the field of circuit technology, and in particular to a power-down control method, device, storage medium, and image signal generator. Background Technology

[0002] The output of the DC-DC converter (DCDC) power supply of the image signal generator (PG) is connected to the external terminals of the PG via a switching module. The external terminals of the PG are connected to the screen under test (SUT) to provide a power signal to the SUT. Furthermore, multiple capacitors are typically connected in parallel at the output of the DCDC power supply for signal denoising and filtering, and multiple capacitors are also connected in parallel at the external terminals of the PG for similar purposes. When the PG is powered off, residual capacitance remains on the multiple parallel capacitors; therefore, it is necessary to discharge the remaining charge on these capacitors.

[0003] In existing technologies, when the DC-DC power supply is controlled to stop outputting voltage, multiple parallel capacitors at the DC-DC power supply output terminal and the external terminal of the PG simultaneously release their remaining charge until the remaining charge is completely released. However, this discharge method does not allow users to precisely control the power-off time, which is insufficient for many applications requiring precise power-off time control.

[0004] Therefore, how to accurately control the power-off time has become an urgent technical problem to be solved. Summary of the Invention

[0005] In view of this, this application provides a power-down control method. 、 The device, storage medium, and image signal generator are designed to precisely control the power-off time by discharging using a first discharge circuit.

[0006] In a first aspect, this application provides a power-down control method, the method comprising:

[0007] In response to the power-down operation, the preset discharge circuit is controlled to discharge, and the output voltage of the adjustable power supply is gradually reduced based on the power-down time.

[0008] When the output voltage of the adjustable power supply is a preset voltage value, the adjustable power supply is controlled to be turned off, and the preset discharge circuit is controlled to continue discharging, so as to complete the final power-off of the output terminal of the adjustable power supply.

[0009] Optionally, the preset voltage value is the minimum voltage value that the adjustable power supply outputs through the digital-to-analog converter module, which is used to control the output voltage value of the adjustable power supply.

[0010] Optionally, controlling the output voltage of the adjustable power supply to gradually decrease based on the power-down time includes:

[0011] Based on the power-down time, the output voltage of the adjustable power supply is gradually reduced in a stepwise manner.

[0012] Optionally, controlling the output voltage of the adjustable power supply to gradually decrease in a stepwise manner based on the power-down time includes:

[0013] The number of steps is determined based on the power-down time and the preset step time;

[0014] The output voltage of the adjustable power supply is controlled according to the number of steps.

[0015] Optionally, the preset discharge circuit includes a first discharge circuit and a second discharge circuit;

[0016] The response to the power-down operation, discharging by controlling a preset discharge circuit, includes:

[0017] Based on the response to the power-down operation, the first discharge circuit is controlled to discharge;

[0018] The step of controlling the preset discharge circuit to continue discharging in order to finally power off the adjustable power supply includes:

[0019] By controlling the first discharge circuit to continue discharging, and simultaneously controlling the second discharge circuit to discharge, the final power-off of the adjustable power supply's output terminal is completed.

[0020] Optionally, the output terminal of the adjustable power supply is connected to the switching module, and the first discharge circuit and the second discharge circuit are correspondingly connected to the connection lines at both ends of the switching module. The method further includes:

[0021] When the output voltage of the adjustable power supply reaches the final power-down voltage, the switch module is triggered to turn off; the final power-down voltage is the power-down voltage value when the output terminal of the adjustable power supply is finally powered down.

[0022] Optionally, the output terminal of the adjustable power supply is connected to the switching module, and the first discharge circuit and the second discharge circuit are respectively connected to the connection lines at both ends of the switching module.

[0023] The method further includes:

[0024] When the output voltage of the adjustable power supply reaches the preset voltage value, the switching module is controlled to turn off.

[0025] Secondly, this application provides a power-off control device, the device comprising: a controller connected to the adjustable power supply, wherein the output terminal of the adjustable power supply is connected to the preset discharge circuit;

[0026] The controller is configured to respond to a power-down operation by controlling the preset discharge circuit to discharge, and by controlling the output voltage of the adjustable power supply to gradually decrease based on the power-down time. When the output voltage of the adjustable power supply is a preset voltage value, the controller controls the adjustable power supply to turn off, and controls the preset discharge circuit to continue discharging, thereby completing the final power-down of the output terminal of the adjustable power supply.

[0027] Thirdly, this application provides a computer-readable storage medium including computer-readable instructions that, when executed on a computing device, cause the computing device to perform the method as described in any of the first aspects.

[0028] Fourthly, this application provides an image signal generator, including the power-down control device described in the second aspect.

[0029] This application provides a power-down control method, apparatus, storage medium, and image signal generator. When executing the method: upon performing a power-down operation, a preset discharge circuit is first used to discharge the power, and the output voltage of an adjustable power supply is gradually reduced based on the power-down time; this process is the first power-down process. When the output voltage of the adjustable power supply drops to a preset voltage value, the adjustable power supply is turned off, and discharge continues through the preset discharge circuit to achieve final power-down of the adjustable power supply output; this process is the second power-down process. Thus, in the first power-down process, the output voltage can be reduced to the preset voltage value within a user-set power-down time, thereby achieving precise user control of the first power-down process. This invention can achieve minimum precise control of the first power-down process within 1ms, resulting in high accuracy. Attached Figure Description

[0030] Figure 1 A schematic diagram of an image signal generator is provided for embodiments of this application;

[0031] Figure 2A A structural block diagram of a preset discharge circuit provided in an embodiment of this application;

[0032] Figure 2B This is a schematic diagram of a preset discharge circuit provided in an embodiment of this application;

[0033] Figure 3 A power-down control method provided in this application embodiment;

[0034] Figure 4 A schematic diagram of a power-down process provided in an embodiment of this application;

[0035] Figure 5A A pre-defined discharge circuit structure framework diagram of a combination of a second discharge circuit and a first discharge circuit provided in an embodiment of this application;

[0036] Figure 5B A circuit diagram of a preset discharge circuit based on the combination of a second discharge circuit and a first discharge circuit, provided for an embodiment of this application;

[0037] Figure 6 A flowchart of another power-down control method provided in this application embodiment;

[0038] Figure 7 This is a schematic diagram of a power-down control device provided in an embodiment of this application. Detailed Implementation

[0039] The term "comprising" and its variations as used herein are open-ended inclusions, meaning "including but not limited to". The term "based on" means "at least partially based on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments". Definitions of other terms will be given in the description below.

[0040] It should be noted that the concepts of "first" and "second" mentioned in this disclosure are used only to distinguish different devices, modules or units, and are not used to limit the order of functions performed by these devices, modules or units or their interdependencies.

[0041] It should be noted that the terms "a" and "a plurality of" used in this disclosure are illustrative rather than restrictive, and those skilled in the art should understand that, unless otherwise expressly indicated in the context, they should be understood as "one or more".

[0042] As mentioned earlier, current PG DC-DC power supplies have multiple capacitors connected in parallel at both the output and external terminals for signal denoising and filtering. However, when the PG is powered off, the DC-DC power supply does not output voltage, and the parallel capacitors across the switching module retain residual charge, requiring a considerable amount of time (greater than 50ms) to fully discharge. This method of directly discharging charge through capacitors cannot meet users' needs for precise power-off control based on preset power-off times.

[0043] To better illustrate the power-down control method provided in this application, we first introduce an image signal generator used in applying the power-down control method. See also... Figure 1 This is an image signal generator provided in an embodiment of this application.

[0044] The image signal generator includes a power-down control device and a power supply module. The power supply module includes: a DC-DC power supply 103 (also known as an adjustable power supply), a sampling module 106, a digital-to-analog converter (DAC) module 102, a switching module 104, and a preset discharge circuit 105. The power-down control device includes a controller 101. The controller includes an FPGA module and a software processor module.

[0045] The specific connection relationships are as follows: the output terminal of controller 101 is connected to the input terminal of DAC module 102; the output terminal of DAC module 102 is connected to the feedback terminal of DC-DC power supply 103; the output terminal of DC-DC power supply 103 is connected to the first terminal of switch module 104; the other terminal of switch module 104 is connected to the input terminal of sampling module; the connection node between switch module 104 and the input terminal of sampling module serves as the output terminal of power supply module to output Vout; and the other terminal of switch module 104 is connected to preset discharge module 105. The other output terminal of controller 101 is connected to preset discharge circuit 105 for controlling the on and off states of preset discharge circuit 105.

[0046] The image signal generator operates as follows: Controller 101 controls the output voltage Vout of the DC-DC power supply via DAC module 102. Preferably, controller 101 controls the DC-DC power supply output in a step-wise manner via DAC module 102. For example, controller 101 sends multiple power-down step code values ​​sequentially to DAC module 102. DAC module 102 converts the power-down step code values ​​into analog signals and sends them to the feedback terminal of DC-DC power supply 103. DC-DC power supply 103 outputs the corresponding output voltage Vout based on the signal input at the feedback terminal, thus ultimately achieving step-wise power-down.

[0047] When the switching module is turned on, the output line of the DC-DC power supply 103 is turned on, and the voltage is output to the external terminal of the DC-DC power supply 103. The sampling module 106 can sample the voltage on the transmission line between the DC-DC power supply 103 and the external terminal and send it to the controller so that the controller can perform subsequent actions based on the sampled voltage, such as transmitting it to the host computer to display the sampled voltage on the host computer.

[0048] When the DC-DC power supply 103 is powered off, the controller responds to the power-off operation by controlling the output voltage of the adjustable power supply based on the power-off time and discharging through the preset discharge circuit. During this process, the output voltage of the adjustable power supply is reduced sequentially to the voltage corresponding to the power-off step code value, so as to achieve a gradual decrease in output voltage. During the gradual decrease, the excess charge generated on the parallel capacitor due to the voltage difference change is rapidly discharged through the preset discharge module 104, which provides support for the power supply voltage to drop rapidly to the voltage corresponding to each power-off step code value. This process belongs to the first discharge process.

[0049] When the output voltage of the adjustable power supply is a preset voltage value, the adjustable power supply is turned off. At this time, there is residual charge on the parallel capacitor. The preset discharge circuit is controlled to continue discharging, and finally the output of the adjustable power supply is powered off. This is the second discharge process.

[0050] In this embodiment, the final power-down voltage is preferably 0V, that is, to achieve complete discharge and ensure circuit safety. Preferably, the preset voltage value mentioned above is the minimum voltage value that the adjustable power supply output is controlled by the digital-to-analog converter module. This means that the power-down voltage is controlled within the maximum range through the first discharge process as much as possible. This allows the user to control the power-down voltage range to the greatest extent possible, and also allows the user to control the power-down process to the greatest extent possible. During the power-down process, discharge is carried out simultaneously, and the power-down time of the DC-DC power supply 103 is precisely controlled.

[0051] It is worth noting that the connection position of the aforementioned preset discharge circuit is a schematic representation on the output line of the DC-DC power supply 103. That is, the preset discharge circuit 101 can be placed between the sampling module 106 and the switching module 104. Furthermore, the preset discharge circuit can also be placed between the DC-DC power supply 103 and the switching module 104. The preset discharge circuit may also include a first discharge circuit and a second discharge circuit, wherein the first discharge circuit is placed between the DC-DC power supply 103 and the switching module 104, and the second discharge circuit is placed between the sampling module 106 and the switching module 104.

[0052] See Figure 2A The diagram shown is a structural block diagram of a preset discharge circuit provided in an embodiment of this application.

[0053] In this embodiment, the preset discharge circuit includes a discharge control module 201 and a discharge resistor 202. The input terminal of the discharge control module 201 is connected to the output terminal of the controller 101, and is used to receive the output level signal Chargein from the controller 101. The output terminal of the discharge control module 201 is connected to the discharge resistor 202, and is used to control the discharge of the discharge resistor 202. The discharge resistor 202 of the preset discharge circuit is connected to the output line of the DC-DC power supply 103, and is used to control the discharge of charge on the output line of the DC-DC power supply 103.

[0054] To better illustrate the embodiments of this application, the following description is provided in conjunction with a specific preset discharge circuit. See [link to relevant documentation]. Figure 2B This is a circuit diagram of a preset discharge circuit provided in an embodiment of this application. The discharge resistor is R0, and the discharge control module includes a switch U1, a transistor Q1, resistors R4, R5, and R3, and a breakdown diode D1 to prevent U1 from being damaged. The specific connection relationships are as follows:

[0055] The power supply is connected to the input terminal of the discharge resistor R0 in the preset discharge circuit via Vin. The output terminal of the discharge resistor R0 is connected to the first terminal of the switching transistor U1 (i.e., the drain terminal of the NMOS transistor shown in the diagram). The input terminal of resistor R0 is connected to the power supply output terminal Vout.

[0056] The second terminal of U1 (i.e., the gate terminal of the NMOS transistor shown in the diagram) is connected to the output terminal of resistor R3, the collector of transistor Q1, and the input terminal of breakdown diode D1. The third terminal of U1 (i.e., the source terminal of the NMOS transistor shown in the diagram) is grounded. The output terminal of resistor R3 is connected to VCC voltage and the collector of Q1. The output terminal of D1 is grounded. D1 is used to prevent U1 from being damaged by breakdown.

[0057] The emitter of Q1 is grounded. The base of Q1 is connected to the output of R4. The input of R4 is connected to the output of R5 and the charge control terminal of the parallel capacitor. The input of R5 is connected to a 3.3V voltage.

[0058] During the power-down process, such as switching from 25V to 0V, the voltage change is significant. To achieve rapid discharge and prevent U1 from breaking down, the discharge resistor R0 should be selected with a large resistance value. The resistance value of the discharge resistor R0 is determined based on the initial power-down voltage and the discharge power. The discharge power is determined by the discharge charge and the discharge time.

[0059] Example illustration: Assuming the discharge power is determined to be 10W based on the discharge charge and discharge time, and the initial voltage is 25V, then the parallel resistance obtained by connecting R1 and R2 in parallel is 62.5Ω. Considering line loss, in actual use, the resistance of R0 is less, for example, 61.1Ω.

[0060] In one possible implementation, the discharge resistor R0 can be obtained by connecting two resistors R1 and R2 with the same resistance value in parallel, thereby increasing the discharge power.

[0061] For example, when the resistance of R0 is 61.1Ω, and the resistances of R1 and R2 are the same, then the resistances of R1 and R2 are 122.2Ω respectively.

[0062] In this embodiment, R1 and R2 are merely resistance values. The required resistance values ​​for R1 and R2 can be obtained by connecting multiple resistors in parallel. For example, to obtain a 122.2Ω resistor, two 330Ω resistors and one 470Ω resistor can be connected in parallel. Furthermore, when selecting resistors, the maximum operating power of the resistors must be considered to avoid resistor breakdown.

[0063] It is worth noting that the number of discharge resistors provided in the embodiments of this application is only illustrative. Those skilled in the art can adjust it as needed, for example, three discharge resistors in parallel, four discharge resistors in parallel, etc.

[0064] R3 is a pull-up resistor for VCC, used to provide the required voltage to the gate (G) of U1. The selection of R3 needs to consider both the breakdown voltage of Q1 and the voltage value that the gate (G) of U1 needs to meet when it is operating. R4 is used to prevent signal distortion, and R5 is a 3.3V pull-up resistor; its value should be determined by considering the voltage value when the transistor is operating normally.

[0065] Example explanation: Assuming VCC is +31V, to ensure the required gate voltage of U1 (Vgs = 10V) and to prevent Q1 from breaking down, the resistance of R3 is chosen to be 100KΩ. Considering that Q1 can work normally, R4 is 1KΩ and R5 is 4.7KΩ.

[0066] The operation of the above discharge circuit is explained below: By default, the base of Q1 is at a high level, Q1 is working normally, the collector of Q1 is at a low level, the gate (G) of U1 is at a low level, U1 is off, and the discharge circuit is not working. When the Charge in input is low, Q1 is off, the collector of Q1 is at a high level, the gate (G) of U1 is at a high level, U1 is on, and the discharge circuit discharges normally.

[0067] U1 can be either an NMOS or a PMOS transistor, as those skilled in the art can choose according to their needs. Q1 can be either an NPN or a PNP transistor, as those skilled in the art can determine according to their needs.

[0068] Below, in conjunction with Figure 1 The image signal generator and the first discharge circuit shown in Figure 2 are used to introduce the power-down control method provided in the embodiments of this application.

[0069] See Figure 3 This application provides a power-down control method, which includes:

[0070] S301: Perform power-down operation.

[0071] Among them, performing a power-down operation means that the user performs the power-down operation through a preset method. For example, the user performs the power-down operation on the host computer.

[0072] In addition, while the user performs the power-down operation on the host computer, they also configure the power-down time, step time, initial voltage value, and target power-down voltage value, and send these settings to the controller. The controller receives the configured parameter values.

[0073] S302: Discharge by controlling the preset discharge circuit, and gradually reduce the output voltage of the adjustable power supply based on the power-down time until the preset voltage value is reached.

[0074] The controller 101 controls the output voltage of the adjustable power supply to gradually decrease based on the power-down time. In one possible implementation, the output voltage of the adjustable power supply can be controlled in a step-by-step manner to a preset voltage value. That is, the output voltage of the adjustable power supply is controlled in multiple steps. The embodiments of this application adopt a step-by-step method, which can precisely control the voltage value of the output voltage of the adjustable power supply at each step as needed.

[0075] In one possible implementation, the controller 101 determines the number of steps based on the power-down time and the step time; and determines the power-down code value corresponding to the output voltage of the adjustable power supply for each step based on the number of steps, so as to control the output voltage of the adjustable power supply for each step.

[0076] The controller 101 inputs the power-down code value of the adjustable power supply output voltage for each step to the DAC module 102, which converts it into the analog output voltage of the adjustable power supply for each step, thereby controlling the output voltage of the adjustable power supply.

[0077] Thus, the controller has a preset method for obtaining the number of steps and a method for obtaining the power-down code value of the adjustable power supply output voltage for each control step. By simply configuring the power-down time, step time, initial voltage value and target power-down voltage value, the output voltage of the DC-DC power supply 103 can be automatically controlled in a step-by-step manner.

[0078] Specifically, the controller uses the following formula to obtain the number of steps:

[0079] Power-down time / step time = number of steps; where the step time can be preset inside the controller.

[0080] Based on the number of steps, the initial voltage, and the target voltage, determine the adjustable power supply output voltage for each step, i.e.:

[0081] (Initial voltage - target power-down voltage) / number of steps = power-down step change code value, where the target power-down voltage is a preset voltage value in the first power-down process;

[0082] Initial voltage - current step count × power-down step change code value = power-down code value of the adjustable power supply output voltage for each step.

[0083] The controller 101 sends the power-down code value of the adjustable power supply's output voltage for each step to the DAC module 102, which performs digital-to-analog conversion. The controller calculates the generated power-down code value of the adjustable power supply's output voltage for each step as a digital voltage, which needs to be converted from digital to analog voltage and sent to the DC-DC power supply 103 to control the output voltage of the DC-DC power supply 103.

[0084] Example Explanation: Assume the initial power-down voltage is 25V, the target power-down voltage is 1V, the power-down time is 4ms, and the step time is 0.1ms. Then the number of steps N is 40 (total number of steps), the voltage corresponding to the power-down step change code value is 0.6V, and the output voltage of the adjustable power supply for each step is 25 - 0.6*n (in V), where n is the current step count (current cumulative count). Controller 101 inputs the power-down code value corresponding to 25 - 0.6*n to DAC module 102, converting it into an analog voltage 25 - 0.6*n, controlling the output voltage of the DC-DC power supply to be 25 - 0.6*n (in V).

[0085] Furthermore, embodiments of this application can also be implemented by setting a fixed output voltage for an adjustable power supply for each step number. For example, the fixed output voltage for the adjustable power supply can be set according to an arithmetic sequence.

[0086] Example description: According to the above embodiment, the number of steps is 40. A fixed adjustable power supply output voltage can be set for each step, which is: 24.98, 24.96, ..., 1.02V. The controller 101 inputs the downcode value of the adjustable power supply output voltage corresponding to the current step number to the DAC module 102, converts it into an analog voltage, and then controls the output voltage of the DC-DC power supply.

[0087] In addition, embodiments of this application can also determine the output voltage of the adjustable power supply at each step based on the number of steps in other ways.

[0088] Meanwhile, the controller 101 controls the preset discharge circuit to perform a discharge operation based on the power-down time. The preset discharge circuit is shown in Figure 2, and will not be described in detail here.

[0089] Thus, by simultaneously discharging during the first power-down process, excess charge due to voltage changes can be completely released from both the capacitors connected in parallel at the external terminals and the capacitors connected in parallel at the DC-DC output terminals. Due to the presence of the preset discharge circuit, the charge stored on the parallel capacitors can be completely released within 1ms, thereby achieving precise control of the power-down time to the preset voltage value.

[0090] S303: When the output voltage of the adjustable power supply is the preset voltage value, control the adjustable power supply to turn off and control the preset discharge circuit to continue discharging, thus completing the final power-off of the adjustable power supply output terminal.

[0091] During the second power-down process, when the output voltage of the adjustable power supply is a preset voltage value, the adjustable power supply is controlled to shut down.

[0092] In one possible implementation, preferably, the controller 10 can be used to turn off the enable switch of the DC-DC power supply 103, thus disabling the DC-DC power supply 103. This application does not limit the method of turning off the adjustable power supply.

[0093] The preset voltage value is preferably the minimum voltage value that the DAC module 102 controls the adjustable power supply output. When the voltage output of the adjustable power supply reaches the preset voltage value, the controller 101 stops controlling the output voltage of the adjustable power supply in a stepping or other manner.

[0094] At this point, the adjustable power supply is turned off, and the preset discharge circuit continues to discharge until the adjustable power supply output reaches the final power-off state.

[0095] Example description: Assume that the minimum voltage value of the adjustable power supply output controlled by DAC module 102 is 1V. When the voltage output of the adjustable power supply reaches 1V, and then continues to power down, the adjustable power supply is turned off and the preset discharge circuit continues to discharge until the output of the adjustable power supply reaches the final power-down value, that is, the output voltage value reaches the final power-down voltage value, such as the output voltage is 0V, and finally the power-down is completely achieved.

[0096] The final power-off voltage value is the power-off voltage value at the final power-off point of the adjustable power supply output terminal. It can be 0V or other values, such as 1V.

[0097] In one possible implementation, the output of the adjustable power supply is connected to the switching module, such as... Figure 1 As shown, when the output voltage of the adjustable power supply reaches the final power-down voltage, the trigger switch module 104 is disconnected. At this time, the preset discharge circuit continues to discharge the residual charge at the external terminal. In this way, the residual charge is completely released while controlling the power-down time.

[0098] This application provides a power-down control method. When a power-down operation is performed, the output voltage of an adjustable power supply is first gradually reduced to a preset voltage value based on the power-down time, and then discharged through a preset discharge circuit. This process is the first power-down process. When the output voltage of the adjustable power supply drops to the preset voltage value, the adjustable power supply is turned off, and the discharge continues through the preset discharge circuit to achieve the final power-down of the adjustable power supply output. This process is the second power-down process. Thus, in the first power-down process, the output voltage can be reduced to the preset voltage value through a power-down time set by the user, thereby achieving precise control of the first power-down process by the user. This invention can achieve minimum precise control of the first power-down process within 1ms, thus providing high control accuracy for the power-down process.

[0099] See Figure 4 The diagram illustrates a power-down process according to an embodiment of this application. For an adjustable power supply, upon receiving a power-down command, a power-down delay is first performed at the initial voltage value (3V as shown in the diagram). When the power-down delay duration meets the delay threshold, the power-down operation is executed. When the output voltage of the adjustable power supply drops from the initial voltage value to a preset voltage value (3V to 1V as shown in the diagram), the first power-down process described above can achieve precise control. When the output voltage of the adjustable power supply drops from the preset voltage value to the final power-down voltage value (1V to 0V as shown in the diagram), this second power-down process, through a preset discharge circuit, also strives to achieve rapid power-down as much as possible.

[0100] In order to achieve rapid discharge during the first and second power-off processes, the preset discharge circuit includes a first discharge circuit and a second discharge circuit, wherein the power of the first discharge circuit is less than that of the second discharge circuit.

[0101] See Figure 5A This application provides a schematic diagram of a pre-defined discharge circuit structure combining a second discharge circuit and a first discharge circuit, as part of an embodiment of the present application. Specifically, it includes:

[0102] The second discharge circuit includes a second discharge control module 501 and a second discharge resistor 502. The input terminal of the second discharge control module 501 is connected to the output terminal of the controller 101 to receive the output level signal "Charge in" from the controller 101. The output terminal of the second discharge control module 501 is connected to the second discharge resistor 502 to control the discharge of the second discharge resistor 502. The second discharge resistor 502 is connected to the output line of the DC-DC power supply 103 and to the first terminal of the switching module S1. It is used for discharging and controlling the charge on the output line of the DC-DC power supply 103.

[0103] The first discharge circuit includes a first discharge control module 503 and a first discharge resistor 504. The input terminal of the first discharge control module 503 is connected to the output terminal of the controller 101 to receive the output level signal "Charge in" from the controller 101. The output terminal of the first discharge control module 503 is connected to the first discharge resistor 504 to control the discharge of the first discharge resistor 504. The other end of the switching module is connected to the first discharge resistor 504 and is also used for discharging and controlling the charge on the output line of the DC-DC power supply 103.

[0104] In this embodiment, the discharge resistance of the second discharge circuit is smaller than that of the first discharge circuit. That is, the second discharge circuit is a low-power discharge circuit, and the first discharge circuit is a high-power discharge circuit. Compared to the high-power discharge circuit, the low-power discharge circuit discharges faster.

[0105] To better illustrate the embodiments of this application, the following description is provided in conjunction with a specific preset discharge circuit. See [link to relevant documentation]. Figure 5B This is a circuit diagram of a preset discharge circuit based on the combination of a second discharge circuit and a first discharge circuit, provided in an embodiment of this application.

[0106] The first discharge resistor 504 of the first discharge circuit is R12 and R11. The first discharge control module 503 includes a switching transistor U11, a transistor Q11, resistors R14, R15 and R13, and a breakdown diode D11 to prevent U11 from being broken down.

[0107] The second discharge resistor 502 of the second discharge circuit is R16. The second discharge control module 501 includes a switching transistor U12, a transistor Q12, resistors R19, R18 and R17, and a breakdown diode D12 to prevent U12 from being broken down.

[0108] The specific connection relationships are as follows:

[0109] The first discharge circuit is connected to the second terminal of the switch module S1, and the second discharge circuit is connected to the first terminal of the switch module S1.

[0110] The specific circuit structure of the first discharge circuit is as follows: The power supply is connected to the input terminals of the discharge resistors R11 and R12 of the first discharge circuit through Vin. The output terminals of the discharge resistors R11 and R12 are connected to the drain (D) terminal of the NMOS transistor U11. Furthermore, the input terminals of resistors R11 and R12 are connected to the power supply output terminal Vout.

[0111] The gate (G) terminal of U11 is connected to the output terminal of resistor R13, the collector of transistor Q11, and the input terminal of breakdown diode D11. The source (S) terminal of U11 is grounded. The output terminal of resistor R13 is connected to VCC voltage and the collector of Q11. The output terminal of D11 is grounded. D11 is used to prevent U11 from being damaged by breakdown.

[0112] The emitter of Q11 is grounded. The base of Q11 is connected to the output of R14. The input of R14 is connected to the output of R15 and the charge control terminal of the parallel capacitor. The input of R15 is connected to a 3.3V voltage.

[0113] During the power-down process, such as from 25V to 0V, the voltage change is large. To achieve rapid discharge and prevent U11 from breaking down, discharge resistors R11 and R12 should be selected with relatively large resistance values. The parallel resistance value obtained by connecting discharge resistors R11 and R12 in parallel is determined based on the initial power-down voltage and the discharge power. Among them, the discharge power is determined by the discharge charge and the discharge time.

[0114] Example illustration: Assuming the discharge power is determined to be 10W based on the discharge charge and discharge time, and the initial voltage is 25V, then the parallel resistance obtained by connecting R1 and R2 in parallel is 62.5Ω. Considering line loss, in actual use, the parallel resistance value is smaller, for example, 61.1Ω.

[0115] In one possible implementation, R11 and R12 have the same resistance value, and the discharge power is increased by connecting R11 and R12 in parallel.

[0116] For example, when the parallel resistance of R11 and R12 is 61.1Ω, and when the resistances of R11 and R12 are the same, the resistances of R11 and R12 are 122.2Ω respectively.

[0117] In this embodiment, R11 and R12 are merely resistance values. The required resistance values ​​for R11 and R12 can be obtained by connecting multiple resistors in parallel. For example, to obtain a 122.2Ω resistor, two 330Ω resistors and one 470Ω resistor can be connected in parallel. Furthermore, when selecting resistors, the maximum operating power of the resistors must be considered to prevent resistor breakdown.

[0118] It is worth noting that the number of discharge resistors provided in the embodiments of this application is only illustrative. Those skilled in the art can adjust it as needed, for example, three discharge resistors in parallel, four discharge resistors in parallel, etc.

[0119] R13 is a pull-up resistor for VCC, used to provide the required voltage to the gate (G) of U11. The selection of R13 needs to consider both the breakdown voltage of Q11 and the voltage value that the gate (G) of U11 needs to meet when it is operating. R14 is used to prevent signal distortion, and R15 is a 3.3V pull-up resistor; its value should be determined by considering the voltage value when the transistor is operating normally.

[0120] Example explanation: Assuming VCC is +31V, to ensure the required gate voltage of U11 (Vgs = 10V) and to prevent Q11 from breaking down, the resistance of R13 is chosen to be 100KΩ. Considering that Q11 can work normally, R14 is 1KΩ and R15 is 4.7KΩ.

[0121] The operation of the above discharge circuit is explained below: By default, the base of Q11 is at a high level, Q11 is working normally, the collector of Q11 is at a low level, the gate (G) of U11 is at a low level, U11 is off, and the discharge circuit is not working. When Chargein input is low, Q11 is off, and the collector of Q11 is at a high level. The gate (G) of U11 is high, U11 is on, and the discharge circuit discharges normally.

[0122] U11 can be either an NMOS or a PMOS transistor, as those skilled in the art can choose according to their needs. Q11 can be either an NPN or a PNP transistor, as those skilled in the art can determine according to their needs.

[0123] The input terminal of the second discharge circuit is connected to the other end of the switching module S1, and the input terminal of the second discharge resistor is connected to the output terminal Vin of the DC-DC power supply. The discharge resistor of the second discharge circuit is smaller than that of the first discharge circuit. That is, the second discharge circuit is a low-power discharge circuit, while the first discharge circuit is a high-power discharge circuit. Compared to the high-power discharge circuit, the low-power discharge circuit discharges faster.

[0124] Example illustration: The resistance of R16 is 10Ω, the resistance of R11 is 122.2Ω, and the resistance of R12 is 122.2Ω. The parallel resistance of R11 and R12 is 61.1Ω. At this time, the resistance of R16 is less than the parallel resistance of R11 and R12. Assuming the initial power-down voltage is 25V, and the preset voltage is 2V, the power of the second discharge circuit is 0.4W, and the power of the first discharge circuit is 5.115W. The power of the second discharge circuit is less than the power of the first discharge circuit.

[0125] The connection of the second discharge circuit is as follows: The second terminal of the switch module S1 is connected to the input terminal of the discharge resistor R16 in the second discharge circuit. The output terminal of the discharge resistor R16 is connected to the drain (D) terminal of the NMOS transistor U12. Furthermore, the input terminal of resistor R16 is connected to one end of the interface of the switch module S1.

[0126] The gate (G) terminal of U12 is connected to the output terminal of resistor R17, the collector of transistor Q12, and the input terminal of breakdown diode D12. The source (S) terminal of U12 is grounded. The output terminal of resistor R17 is connected to VCC voltage and the collector of Q12. The output terminal of D12 is grounded. D12 is used to prevent U12 from being damaged by breakdown.

[0127] The emitter of Q12 is grounded. The base of Q12 is connected to the output of R18. The input of R18 is connected to the output of R19 and the charge control terminal of the parallel capacitor. The input of R19 is connected to a 3.3V voltage.

[0128] During the power-down process, the voltage change is small from the preset voltage value to the final power-down, requiring rapid discharge. Therefore, the resistance of the discharge resistor R16 should be small during this time. The specific resistance value of R16 is determined based on the initial power-down voltage and the discharge power. The discharge power is determined by the discharge charge and the discharge time.

[0129] Example illustration: Assuming the discharge power is determined to be 0.4W based on the discharge charge and discharge time, and the preset voltage is 2V, then the resistance of R16 is 10Ω.

[0130] R17 is a pull-up resistor for VCC, used to provide the required voltage for the gate (G) of U12. The selection of R17 needs to consider both the breakdown voltage of Q12 and the voltage value that the gate (G) of U12 needs to meet when it is operating. R18 is used to prevent signal distortion, and R19 is a 3.3V pull-up resistor; its value should be determined by considering the voltage value when the transistor is operating normally.

[0131] Example explanation: Assuming VCC is +31V, to ensure the required voltage for U12G stage (Vgs = 10V) and to prevent Q12 from breaking down, the resistance of R17 is chosen to be 100KΩ. Considering that Q12 can work normally, R18 is 1KΩ and R19 is 4.7KΩ.

[0132] The operation of the discharge circuit described above is explained below: By default, the base of Q12 is at a high level, Q12 operates normally, and the collector of Q12 is at a low level. The gate (G) of U12 is also at a low level, and U12 is off, meaning the discharge circuit is not working. When the Chargein input is low, Q12 is off, and its collector is at a high level. The gate (G) of U12 is high, and U12 is on, meaning the discharge circuit discharges normally.

[0133] U12 can be either an NMOS or a PMOS transistor, as those skilled in the art can choose according to their needs. Q12 can be either an NPN or a PNP transistor, as those skilled in the art can determine according to their needs.

[0134] In one possible implementation, R17 has the same resistance value as R13, R18 has the same resistance value as R14, and R19 has the same resistance value as R15; all resistors can be of the same type. U11 and U12 can be MOSFETs of the same type. Q11 and Q12 can be MOSFETs of the same type. D12 and D11 can be MOSFETs of the same type.

[0135] See Figure 6Figure 5 shows another power-down control method flowchart provided in this application embodiment. This method uses the preset discharge circuit shown in Figure 5. The method includes:

[0136] S601: Perform power-down operation.

[0137] The same steps are as in step S301, so they will not be repeated here.

[0138] S602: Controls the first discharge circuit to discharge, and controls the output voltage of the adjustable power supply to gradually decrease based on the power-down time until the preset voltage value is reached.

[0139] The process of gradually reducing the output voltage of the adjustable power supply based on the power-down time is the same as step S302, and will not be repeated here.

[0140] The first discharge circuit is connected on the output line between the sampling module 106 and the switching module 104. It is used to release excess stored charge on the parallel capacitor at the output terminal of the DC-DC power module 103 and the parallel capacitor at the external terminal during the first power-down process.

[0141] The circuit diagram of the first discharge circuit is shown in Figure 5, and will not be repeated here.

[0142] In the embodiments of this application, the first discharge circuit can realize the release of part of the charge stored in the parallel capacitor at the output terminal of the DC-DC power module 103 and the parallel capacitor at the external terminal during the first power-down process.

[0143] Example illustration: The discharge resistors R11 and R12 in the first discharge circuit have resistance values ​​of 122.2Ω, and the initial voltage is 25V, at which point the discharge power is 10.23W. This rapidly releases the residual charge of the parallel capacitors at the output terminals of the DC-DC power module 103 and the parallel capacitors at the external terminals, thereby supporting the step-by-step reduction of the output voltage of the power module 103.

[0144] S603: When the output voltage of the adjustable power supply is a preset voltage value, control the adjustable power supply to turn off, and at the same time control the first discharge circuit and the second discharge circuit to discharge.

[0145] During the second power-down process, when the output voltage of the adjustable power supply drops to the preset voltage value, the adjustable power supply is shut down, and the second discharge circuit is opened, utilizing both the first and second discharge circuits to discharge simultaneously. This process continues until the final power-down of the adjustable power supply output is completed.

[0146] The preset voltage value is the same as the preset voltage value in step S303, so it will not be repeated here.

[0147] The input terminal of the second discharge circuit is connected to the output terminal of the DC-DC power supply, and is used for rapid discharge when the output voltage of the adjustable power supply is a preset voltage value. A circuit diagram of the second discharge circuit is shown in Figure 5 above and will not be described further here. The output terminal of the DC-DC power supply 103 is connected to the switching module 104, and the output terminal of the switching module 104 is connected to the first discharge circuit. The input terminal of the switching module 104 is connected to the second discharge circuit.

[0148] That is, the output terminal of the adjustable power supply is connected to the switching module, and the first discharge circuit and the second discharge circuit are connected to the connection lines at both ends of the switching module 104.

[0149] In one possible implementation, the switch module 104 is triggered to disconnect when the output voltage of the adjustable power supply reaches the final power-down voltage. The final power-down voltage is the power-down voltage value at which the output terminal of the adjustable power supply is finally powered down.

[0150] In this embodiment, to further improve the rapid discharge during the power-down process and further improve the accuracy of controlling the power-down time, any of the following methods can be used:

[0151] When the output voltage of the adjustable power supply is the preset voltage value, the switch module 104 remains on, and discharges simultaneously using the first discharge circuit and the second discharge circuit to increase the discharge speed.

[0152] When the output voltage of the adjustable power supply reaches the preset voltage value, the control switch module 104 is disconnected. Then, the first and second discharge circuits on both sides of the switch module 104 can independently continue discharging the parallel capacitors on both sides of the switch module 104. That is, the parallel capacitors at the DC-DC power supply output end have a larger residual charge, which is discharged using the lower-power second discharge circuit; the parallel capacitors on the sampling module side have a smaller residual charge, which is discharged using the higher-power first discharge circuit.

[0153] In this embodiment, the second discharge circuit has lower power than the first discharge circuit. Because the voltage drop range from the preset value to the final voltage is small, and the user has no control over the power-down process, a faster power-down is needed within this range to achieve precise control of the power-down time. Therefore, the second discharge circuit uses a low-power circuit, i.e., a small discharge resistance and a large discharge current, which allows for faster release of the charge stored in the parallel capacitor compared to the first discharge circuit. In other words, the discharge speed is faster than that of the first discharge circuit.

[0154] Furthermore, embodiments of this application also provide a power-down control device. See also Figure 7 This is a schematic diagram of a power-down control device 700 provided in an embodiment of this application. The device 700 includes:

[0155] The controller 701, connected to the adjustable power supply, is used to respond to a power-down operation by discharging through a preset discharge circuit and gradually reducing the output voltage of the adjustable power supply based on the power-down time; and when the output voltage of the adjustable power supply is a preset voltage value, to control the adjustable power supply to turn off and continue discharging through the preset discharge circuit to complete the final power-down of the output terminal of the adjustable power supply.

[0156] The preset discharge circuit 702 is connected to the output terminal of the adjustable power supply and is used to discharge when the power is off.

[0157] Optionally, the preset voltage value is the minimum voltage value that the adjustable power supply output is controlled by the digital-to-analog converter module, which is used to control the output voltage value of the adjustable power supply.

[0158] Optionally, the controller 701 is configured to control the output voltage of the adjustable power supply to gradually decrease in a stepwise manner based on the power-down time.

[0159] Optionally, the controller 701 is also used to determine the number of steps based on the power-down time and a preset step time, and to control the output voltage of the adjustable power supply during each step based on the number of steps.

[0160] Optionally, the preset discharge circuit includes a first discharge circuit and a second discharge circuit; the controller 701 is specifically used to discharge by controlling the first discharge circuit in response to a power-down operation; and while controlling the first discharge circuit to continue discharging, it also controls the second discharge circuit to discharge, so as to complete the final power-down of the output terminal of the adjustable power supply.

[0161] Optionally, the output terminal of the adjustable power supply is connected to the switching module, and the first discharge circuit and the second discharge circuit are respectively connected to the connection lines at both ends of the switching module. With the output terminal of the adjustable power supply connected to the switching module, the controller 701 is also used to trigger the switching module to turn off when the output voltage value of the adjustable power supply reaches the final power-down voltage value; the final power-down voltage is the power-down voltage value at which the output terminal of the adjustable power supply is finally powered down.

[0162] Optionally, the output terminal of the adjustable power supply is connected to the switching module, and the first discharge circuit and the second discharge circuit are correspondingly connected to the connection lines at both ends of the switching module. The controller 701 is also used to control the switching module to turn off when the output voltage value of the adjustable power supply reaches the preset voltage value.

[0163] The specific implementation method is the same as the method implementation example, and will not be repeated here.

[0164] This application provides a power-down control device, including a preset discharge circuit 702 connected to the output terminal of an adjustable power supply for discharging during power-down. The controller 701, when performing a power-down operation, first controls the adjustable power supply to output a gradually decreasing voltage based on the power-down time, while simultaneously discharging through the preset discharge circuit. When the output voltage of the adjustable power supply reaches a preset voltage value, the adjustable power supply is turned off, and discharging continues through the preset discharge circuit to achieve final power-down of the adjustable power supply output terminal. Thus, the stored charge on the parallel capacitor is released through two power-down processes during power-down. Because the preset discharge circuit discharges quickly, within 1ms, the power-down can be precisely controlled based on the power-down time.

[0165] This application also provides corresponding devices and computer-readable storage media for implementing the power-down control method provided in this application.

[0166] The device includes a memory and a processor. The memory is used to store instructions or code, and the processor is used to execute the instructions or code to cause the device to perform a power-down control method according to any embodiment of this application.

[0167] In practical applications, the computer-readable storage medium can be any combination of one or more computer-readable media. The computer-readable medium can be a computer-readable signal medium or a computer-readable storage medium. For example, a computer-readable storage medium can be, but is not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of computer-readable storage media (a non-exhaustive list) include: an electrical connection having one or more wires, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof. In this embodiment, the computer-readable storage medium can be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, apparatus, or device.

[0168] Computer-readable signal media may include data signals propagated in baseband or as part of a carrier wave, carrying computer-readable program code. Such propagated data signals may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. Computer-readable signal media may also be any computer-readable medium other than computer-readable storage media, capable of sending, propagating, or transmitting programs for use by or in connection with an instruction execution system, apparatus, or device.

[0169] Program code contained on a computer-readable medium may be transmitted using any suitable medium, including but not limited to wireless, wire, optical fiber, RF, etc., or any suitable combination thereof.

[0170] Computer program code for performing the operations of this invention can be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages ​​such as Java, Smalltalk, and C++, as well as conventional procedural programming languages ​​such as "C" or similar programming languages. The program code can be executed entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving remote computers, the remote computer can be connected to the user's computer via any type of network—including a local area network (LAN) or a wide area network (WAN)—or can be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0171] It should also be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0172] The above description is merely one specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A power-down control method, characterized in that, The method includes: In response to the power-down operation, the preset discharge circuit is controlled to discharge, and the output voltage of the adjustable power supply is gradually reduced based on the power-down time. When the output voltage of the adjustable power supply is a preset voltage value, the adjustable power supply is controlled to be turned off, and the preset discharge circuit is controlled to continue discharging, so as to complete the final power-off of the output terminal of the adjustable power supply.

2. The method according to claim 1, characterized in that, The preset voltage value is the minimum voltage value that the adjustable power supply outputs through the digital-to-analog converter module, which is used to control the output voltage value of the adjustable power supply.

3. The method according to claim 1, characterized in that, The output voltage of the adjustable power supply based on power-down time control gradually decreases, including: Based on the power-down time, the output voltage of the adjustable power supply is gradually reduced in a stepwise manner.

4. The method according to claim 3, characterized in that, The step-wise control of gradually decreasing the output voltage of the adjustable power supply based on the power-down time includes: The number of steps is determined based on the power-down time and the preset step time; The output voltage of the adjustable power supply is controlled according to the number of steps.

5. The method according to claim 1, characterized in that, The preset discharge circuit includes a first discharge circuit and a second discharge circuit. The response to the power-down operation, discharging by controlling a preset discharge circuit, includes: Based on the response to the power-down operation, the first discharge circuit is controlled to discharge; The step of controlling the preset discharge circuit to continue discharging in order to finally power off the adjustable power supply includes: By controlling the first discharge circuit to continue discharging, and simultaneously controlling the second discharge circuit to discharge, the final power-off of the adjustable power supply's output terminal is completed.

6. The method according to claim 5, characterized in that, The output terminal of the adjustable power supply is connected to the switching module, and the first discharge circuit and the second discharge circuit are respectively connected to the connection lines at both ends of the switching module. The method further includes: When the output voltage of the adjustable power supply reaches the final power-down voltage, the switch module is triggered to turn off; the final power-down voltage is the power-down voltage value when the output terminal of the adjustable power supply is finally powered down.

7. The method according to claim 5, characterized in that, The output terminal of the adjustable power supply is connected to the switching module, and the first discharge circuit and the second discharge circuit are respectively connected to the connection lines at both ends of the switching module. The method further includes: When the output voltage of the adjustable power supply reaches the preset voltage value, the switching module is controlled to turn off.

8. A power-down control device, characterized in that, The device includes: a controller connected to an adjustable power supply, wherein the output terminal of the adjustable power supply is connected to a preset discharge circuit; The controller is configured to respond to a power-down operation by controlling the preset discharge circuit to discharge, and by controlling the output voltage of the adjustable power supply to gradually decrease based on the power-down time. When the output voltage of the adjustable power supply is a preset voltage value, the controller controls the adjustable power supply to turn off, and controls the preset discharge circuit to continue discharging, thereby completing the final power-down of the output terminal of the adjustable power supply.

9. A computer-readable storage medium, characterized in that, Includes computer-readable instructions that, when executed on a computing device, cause the computing device to perform the method of any one of claims 1-7.

10. An image signal generator, characterized in that, Includes the power-down control device as described in claim 8.

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