An overcurrent protection method and a digital light source controller

Abstract

The present application relates to an overcurrent protection method and a digital light source controller, which can solve the problem of large overcurrent protection range of existing digital light source controllers to a certain extent. The digital light source controller includes a main control module, a PWM driving module, a switching module, a power supply module, a current detection module, and an N-channel light source interface. The overcurrent protection method includes determining the luminous current and average current according to the sampling resistance value, sampling voltage value, and duty cycle of the PWM for each light source interface; when the luminous current is greater than k times the maximum continuous operating current of the MOS transistor, or when the average current is greater than 1.1 times the rated current of the digital light source controller, the corresponding light source interface channel starts overcurrent protection; the present application reduces the influence of interference and noise on the signal through the combined conditions of the luminous current and average current and the corrected duty cycle of the PWM, provides precise overcurrent protection, and ensures the reliability of the digital light source controller.

Description

Technical Field

[0001] The present application relates to the field of overcurrent protection of a light source controller, and particularly to an overcurrent protection method and a digital light source controller. Background Art

[0002] With the increasing maturity of machine vision automatic detection technology, light source controllers are widely used in machine vision systems to control light sources during the appearance inspection of various products.

[0003] Digital light source controllers mainly adopt Pulse Width Modulation (PWM for short) control mode to achieve high-efficiency electro-optical conversion. In related technologies, through the overcurrent protection function inherent in the power supply module of the digital light source controller, overcurrent protection of the digital light source controller in PWM control is achieved, and the overcurrent protection point is set to 110% - 160% of the rated value, or even a larger range.

[0004] However, the range of the overcurrent protection function inherent in the power supply module is too large, which aims at the protection of the power supply module and does not match the PWM control application of the digital light source controller, and cannot adapt to the overcurrent protection of the digital light source controller. Summary of the Invention

[0005] To solve the problem of the large overcurrent protection range of the existing digital light source controller, the present application provides an overcurrent protection method and a digital light source controller.

[0006] The embodiments of the present application adopt the following technical solutions:

[0007] In a first aspect, the present application provides a digital light source controller, including: a main control module, a PWM driving module, a switching module, a power supply module, a current detection module, and an N-channel light source interface.

[0008] The power supply module is connected to the first interface of the light source interface; the switching module includes an MOS transistor, the switching module is connected to the second interface of the light source interface, and the switching module is used to control the on-off of the second interface; the current detection module includes a sampling resistor, the current detection module is electrically connected to the switching module and the main control module, and the current detection module is used to convert the current signal passing through the switching module to obtain a sampling voltage, and send the sampling voltage to the main control module.

[0009] The main control module, the PWM driving module, and the switching module are electrically connected in sequence; the main control module is configured to:

[0010] Obtain the sampling resistance value, sampling voltage value, and PWM duty cycle of each light source interface channel. The sampling resistance value is the resistance value of the sampling resistance in the current detection module, and the sampling voltage value is the voltage value of the sampling voltage sent by the current detection module;

[0011] Determine the luminous current and average current of the corresponding light source interface channel according to the sampling resistance value, sampling voltage value, and PWM duty cycle;

[0012] When the luminous current is greater than k times the maximum continuous operating current of the MOS transistor, the corresponding light source interface channel starts overcurrent protection, where k is determined according to the MOS transistor;

[0013] Alternatively, when the average current is greater than 1.1 times the rated current of the digital light source controller, the corresponding light source interface channel starts overcurrent protection.

[0014] Combined with the first aspect, in an implementable manner, the PWM driving module further includes a MOS driving chip, and the MOS driving chip is electrically connected to the MOS transistor; the MOS driving chip is used to perform level conversion on the PWM control signal and provide a large-current drive, and the large-current drive is used to meet the drive requirements of the PWM control signal when the MOS transistor switches quickly.

[0015] Combined with the first aspect, in an implementable manner, the current detection module further includes a second-order RC filter rectifier circuit; the second-order RC filter rectifier circuit is used to obtain a sampling voltage, and the sampling voltage is obtained by passing the voltage of the PWM control signal on the sampling resistance through the second-order RC filter rectifier circuit.

[0016] Combined with the first aspect, in an implementable manner, the current detection module is further configured to correct the duty cycle of the PWM non-linearly.

[0017] As can be seen from the above technical solutions, a digital light source controller provided by the present application includes a main control module, a PWM driving module, a switching module, a power supply module, a current detection module, and an N-channel light source interface. The power supply module is connected to the first interface of the light source interface; the switching module includes a MOS transistor, and the switching module is connected to the second interface of the light source interface, and the switching module is used to control the on-off of the second interface; the current detection module includes a sampling resistor, and the current detection module is electrically connected to the switching module and the main control module, and the current detection module is used to convert the current signal passing through the switching module to obtain a sampling voltage, and send the sampling voltage to the main control module. The main control module is configured to: determine the luminous current and the average current according to the sampling resistance value, the sampling voltage value, and the duty cycle of the PWM for each light source interface channel; when the luminous current is greater than k times the maximum continuous operating current of the MOS transistor, or when the average current is greater than 1.1 times the rated current of the digital light source controller, the corresponding light source interface channel starts overcurrent protection, where k is determined according to the MOS transistor; the present application sets conditions by combining the luminous current and the average current, corrects the duty cycle of the PWM, reduces the influence of interference and noise on the signal, provides accurate overcurrent protection, and improves the reliability of the digital light source controller.

[0018] In a second aspect, the present application provides an overcurrent protection method, and the overcurrent protection method includes:

[0019] Obtain the sampling resistance value, the sampling voltage value, and the duty cycle of the PWM for each light source interface channel, where the sampling resistance value is the resistance value of the sampling resistor in the current detection module, and the sampling voltage value is the voltage value of the sampling voltage sent by the current detection module;

[0020] Determine the luminous current and the average current of the corresponding light source interface channel according to the sampling resistance value, the sampling voltage value, and the duty cycle of the PWM;

[0021] When the luminous current is greater than k times the maximum continuous operating current of the MOS transistor, the corresponding light source interface channel starts overcurrent protection, where k is determined according to the MOS transistor;

[0022] Or, when the average current is greater than 1.1 times the rated current of the digital light source controller, the corresponding light source interface channel starts overcurrent protection.

[0023] Combined with the second aspect, in an implementable manner, according to the sampling resistance value, the sampling voltage value, and the duty cycle of the PWM, determine the luminous current, and the luminous current is calculated according to the following formula:

[0024]

[0025] In the formula, I aLet \(I\) be the luminous current, \(R\) be the value of the sampling resistor, \(V\) be the sampling voltage value, and \(D\) be the duty cycle of the PWM.

[0026] In combination with the second aspect, in one implementable manner, the duty cycle of the PWM is obtained through non-linear correction.

[0027] In combination with the second aspect, in one implementable manner, the duty cycle of the PWM is calculated according to the following formula:

[0028]

[0029] In the formula, \(D\) is the duty cycle of the PWM, \(X\) is the brightness level, the brightness level is an integer within 0 to 255, and \([\cdot]\) is the rounding function.

[0030] In combination with the second aspect, in one implementable manner, according to the sampling resistor value and the sampling voltage value, the average current is determined, and the average current is calculated according to the following formula:

[0031] I b = V / R

[0032] In the formula, \(I\) b is the average current, \(R\) is the value of the sampling resistor, and \(V\) is the sampling voltage value.

[0033] In combination with the second aspect, in one implementable manner, the sampling voltage value is the DC average value.

[0034] From the above technical solutions, it can be seen that an overcurrent protection method provided by this application includes obtaining the sampling resistor value, the sampling voltage value, and the duty cycle of the PWM. The sampling resistor value is the resistance value of the sampling resistor in the current detection module, and the sampling voltage value is the voltage value of the sampling voltage sent by the current detection module; according to the sampling resistor value, the sampling voltage value, and the duty cycle of the PWM of each light source interface channel, the luminous current and the average current are determined; when the luminous current is greater than \(k\) times the maximum continuous operating current of the MOS transistor, or when the average current is greater than 1.1 times the rated current of the digital light source controller, the corresponding light source interface channel starts overcurrent protection, where \(k\) is determined according to the MOS transistor; this application sets conditions through the combination of the luminous current and the average current, corrects the duty cycle of the PWM, reduces the influence of interference and noise on the signal, provides accurate overcurrent protection, and improves the reliability of the digital light source controller. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0036] Figure 1 This is a schematic structural diagram of the digital light source controller and the light source in the embodiment of the present application;

[0037] Figure 2 This is a schematic diagram of the MOS transistor drive and current detection in the embodiment of the present application;

[0038] Figure 3 This is a flowchart of an overcurrent protection method in the embodiment of the present application. Detailed implementation manners

[0039] In order to enable those skilled in the art to better understand the solution of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0040] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and do not necessarily need to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of the present application described here can be implemented in an order other than those illustrated or described here. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device including a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0041] The digital light source controller mainly adopts the PWM control method to achieve high-efficiency electro-optical conversion and avoid the color deviation phenomenon of analog dimming of the light source. In the related art, the digital light source controller does not have an overcurrent protection function, or the overcurrent protection function inherent in the power supply module in the digital light source controller is used to achieve the overcurrent protection of the digital light source controller under PWM control, and the overcurrent protection point is set to 110% - 160% of the rated value, or even a larger range.

[0042] To improve the overcurrent protection performance of the digital light source controller, the embodiment of the present application provides a digital light source controller, which provides precise overcurrent protection based on the PWM control method of the digital light source controller. As Figure 1As shown, the digital light source controller includes a main control module 10, a PWM driving module 20, a switching module 30, a power supply module 50, a current detection module 40, and an N-channel light source interface.

[0043] The main control module 10 may include a control unit, an ADC sampling unit, and a PWM output unit. Among them, the control unit, the ADC sampling unit, and the PWM output unit can be implemented by a micro control unit (Micro Control Unit, abbreviated as: MCU), or can be implemented by a combination of functional chips such as an MCU and an AD chip. The main control module 10 provides an ADC sampling function and a PWM output function.

[0044] The main control module 10 is electrically connected to the negative electrode of the light source through the PWM driving module 20, the switching module 30, and each light source interface channel, and the power supply module 50 is electrically connected to the positive electrode of the light source through each light source interface channel; in the digital light source controller, the main control module 10 outputs a PWM control signal, which is driven by the PWM driving module 20 to drive and control the metal-oxide-semiconductor field effect transistor (metal oxide semiconductor, abbreviated as: MOS) in the switching module 30, and is electrically connected to the light source through the positive and negative electrodes of each light source interface channel to achieve the brightness control of the light source.

[0045] The PWM driving module includes a MOS driving chip, and the MOS driving chip is electrically connected to the MOS tube; the MOS driving chip is used for level conversion of the PWM control signal and providing a large current drive; among them, the large current drive is used to meet the drive requirements of the MOS tube for the PWM control signal during fast switching.

[0046] The MOS tube in the switching module 30 serves as a switch, is connected to the ground plane, and controls the on and off of the MOS tube through the high and low levels of the PWM control signal (that is, controls the on and off of the negative electrode of the light source by the on and off of the PWM control signal passing through the MOS tube).

[0047] As Figure 2 shown, it is a schematic diagram of MOS tube driving and current detection, involving the switching module 30, the current detection module 40, and the light source interface. The switching module 30 includes a MOS tube Q1.

[0048] The current detection module 40 includes a sampling resistor and a second-order RC filter rectifier circuit. Among them, the sampling resistor may include a first resistor R1 and a second resistor R2 connected in parallel, and the resistance value of the sampling resistor is small; the second-order RC filter rectifier circuit may include a third resistor R3, a fourth resistor R4, a first capacitor C1, and a second capacitor C2.

[0049] The voltage of PWM on the sampling resistor is rectified by a second-order RC filter rectification circuit to obtain a sampling voltage, and the sampling voltage is a DC average value.

[0050] The positive pole of the light source is connected to the power supply module 50 through the light source interface, and the negative pole of the light source is connected to the MOS tube of the switch module 30 through the light source interface, and is used to receive the PWM pulse signal to supply power to the light source.

[0051] In some embodiments, when the output specification of the power adapter is 0-2.5A, the sampling resistor can select a resistance value of 0.1Ω.

[0052] As Figure 2 shown, PWM1 is the PWM control signal output from the main control chip. Since the PWM signal has a high frequency (from dozens of kHz to hundreds of kHz), the rising and falling edges of the PWM signal are short, and the charging and discharging current of the gate capacitance of the MOS tube is large, a large-current PWM control signal is provided through the MOS drive chip;

[0053] The main control module 10 is electrically connected to the switch module 30 through the current detection module 40. Among them, the current detection module 40 detects the current signal passing through the MOS tube in the switch module 30. The current signal is converted into a voltage signal through the current detection module 40. The ADC sampling unit of the main control module 10 samples the voltage signal, determines the luminous current and the average current according to the voltage signal, and controls whether to start overcurrent protection through the determination conditions combined with the luminous current and the average current, so as to achieve precise overcurrent protection of the digital light source controller and improve the reliable performance of the digital light source controller.

[0054] The main control module is configured to achieve precise overcurrent protection through the following process. Specifically: obtain the sampling resistor value, sampling voltage value and PWM duty cycle of each light source interface channel. The sampling resistor value is the resistance value of the sampling resistor in the current detection module 40, and the sampling voltage value is the voltage value of the sampling voltage sent by the current detection module 40; determine the luminous current and average current of the corresponding light source interface channel according to the sampling resistor value, sampling voltage value and PWM duty cycle of each light source interface channel; when the luminous current is greater than k times the maximum continuous working current of the MOS tube, the corresponding light source interface channel starts overcurrent protection, where k is determined according to the MOS tube, and the typical value range of k is 0.3-0.6; or when the average current is greater than 1.1 times the rated current of the digital light source controller, the corresponding light source interface channel starts overcurrent protection.

[0055] For the PWM duty cycle of the digital light source controller, a non-linear correction method is provided to improve the accuracy of the luminous current, thereby further improving the accuracy of overcurrent protection.

[0056] The working principle of the digital light source controller is that when the PWM control signal acts on the MOS transistor, a PWM pulse signal close to 24V is provided through the light source interface to supply power to the light source; by adjusting the duty cycle of the PWM control signal, the lighting time of the light source within a PWM cycle can be adjusted, and thus the brightness of the light source can be regulated.

[0057] As can be seen from the above technical solutions, a digital light source controller provided by the present application includes a main control module, a PWM driving module, a switching module, a power supply module, a current detection module, and an N-channel light source interface. The power supply module is connected to the first interface of the light source interface; the switching module includes a MOS transistor, and the switching module is connected to the second interface of the light source interface, and the switching module is used to control the on / off of the second interface; the current detection module includes a sampling resistor, and the current detection module is electrically connected to the switching module and the main control module, and the current detection module is used to convert the current signal passing through the switching module to obtain a sampling voltage, and send the sampling voltage to the main control module. The main control module is configured to: determine the lighting current and average current of the corresponding light source interface channel according to the sampling resistor value, sampling voltage value, and duty cycle of the PWM of each light source interface channel; when the lighting current is greater than k times the maximum continuous operating current of the MOS transistor, or when the average current is greater than 1.1 times the rated current of the digital light source controller, the corresponding light source interface channel starts overcurrent protection, where the typical value range of k is 0.3 to 0.6; the present application corrects the duty cycle of the PWM by combining the settings of the lighting current and average current, reduces the influence of interference and noise on the signal, provides accurate overcurrent protection, and improves the reliability of the digital light source controller.

[0058] Some embodiments of the present application provide an overcurrent protection method, which is applied to the above digital light source controller to provide accurate overcurrent protection; as Figure 3 shown, the overcurrent protection method includes the following steps:

[0059] S101. Obtain the sampling resistor value, sampling voltage value, and duty cycle of the PWM of each light source interface channel.

[0060] The sampling resistor value is the resistance value of the sampling resistor in the current detection module, and the sampling voltage value is the voltage value of the sampling voltage sent by the current detection module; the sampling voltage value is the DC average value.

[0061] S102. Determine the lighting current and average current of the corresponding light source interface channel according to the sampling resistor value, sampling voltage value, and duty cycle of the PWM.

[0062] The sampling resistance value is represented by R, the sampling voltage value obtained after second-order filtering and rectification is represented by V. The sampling voltage is a DC average value. The duty cycle of PWM is represented by D, and the luminous current is represented by Ia (luminous during the time when PWM is at high level). The average current is represented by I b The rated current of the digital light source controller is I o (determined by the rated power of the internal power supply module of the digital light source controller), and the maximum continuous operating current of the MOS transistor is I M . The brightness setting of the digital light source controller is usually 256 levels, and the brightness setting value is X. X takes integer values in the range of 0 to 255.

[0063] Through the formula V = I a *R*D, the calculation formula for the luminous current is obtained. The luminous current is calculated according to the following formula:

[0064]

[0065] In the formula, I a is the luminous current, R is the sampling resistance value, V is the sampling voltage value, and D is the duty cycle of PWM.

[0066] Among them, the duty cycle of PWM is generally obtained through the formula D = X / 255. However, problems may occur when the brightness setting value is low. For example, when X = 0, there is a problem with the calculation of I a , and when X is an integer within 1 to 10, the calculation of I a is affected by noise. Because when X takes integer values within 1 to 10, the sampling voltage value is only a few mv to more than a dozen mv. Small signals are easily affected by interference and noise. In this application, the duty cycle of PWM is obtained through non-linear correction. The duty cycle of PWM is calculated according to the following formula:

[0067]

[0068] In the formula, D is the duty cycle of PWM, X is the brightness level, the brightness level is an integer within 0 to 255, and [] is the rounding function.

[0069] Through the rounding function and progressive correction, when X = 0, it is equivalent to a correction of X + 10; when X = 255, the correction of X is 0. That is, when the X setting value is the smallest, the maximum correction is performed, and when the X setting value is the largest, no correction is performed, minimizing the influence of interference and noise on the signal, and at the same time minimizing the influence on the calculation of the luminous current I a during normal use.

[0070] In some embodiments, when the digital light source controller is in normal use (i.e., when the brightness level is greater than 50), the calculation deviation of its luminous current I a is small.

[0071] And, the average current is calculated as follows:

[0072] I b =V / R

[0073] In the formula, I b is the average current, R is the sampling resistance value, and V is the sampling voltage value.

[0074] S103. When the light-emitting current is greater than k times the maximum continuous operating current of the MOS tube, or when the average current is greater than 1.1 times the rated current of the digital light source controller, the corresponding light source interface channel starts overcurrent protection, where k is determined according to the MOS tube.

[0075] When I b >1.1I o , or, when I a >kI M When the corresponding light source interface channel starts overcurrent protection, the typical value range of k is 0.3~0.6, and the coefficient k is based on I M Sure.

[0076] In some embodiments, the maximum continuous operating current I M Large margin, I o Several times of.

[0077] When using the PWM control method, the average current of the light source determines the brightness of the light source. Too large a light current will affect the reliability of the digital light source controller. Therefore, setting an overcurrent protection mechanism based on a single light current or average current has low reliability.

[0078] For example, if only the average current is used as the basis, in an application with a small PWM duty cycle and a high-power light source load is connected, even if the average current does not exceed the standard, the light-emitting current is very large and may exceed the tolerance of the MOS tube and damage the MOS tube.

[0079] For example, if only the light-emitting current is used as the basis, it is difficult to set the overcurrent protection condition. When the overcurrent protection condition is set low, the power limit of the connected light source load is low, and the versatility of the digital light source controller is reduced. When the overcurrent protection condition is set high, when a larger power light source load is connected, the average current is likely to exceed the rated power of the digital light source controller, affecting the service life of the digital light source controller.

[0080] Therefore, the present application sets conditions by combining the luminous current and the average current, combined with the duty cycle correction of PWM, to reduce the impact of interference and noise on the signal, provide accurate over-current protection, and improve the reliability of the digital light source controller.

[0081] As can be seen from the above technical solutions, an overcurrent protection method provided by this application includes obtaining the sampling resistance value, sampling voltage value, and PWM duty cycle of each light source interface channel. The sampling resistance value is the resistance value of the sampling resistor in the current detection module, and the sampling voltage value is the voltage value of the sampling voltage sent by the current detection module. Determine the luminous current and average current of the corresponding light source interface channel according to the sampling resistance value, sampling voltage value, and PWM duty cycle. When the luminous current is greater than k times the maximum continuous operating current of the MOS transistor, or when the average current is greater than 1.1 times the rated current of the digital light source controller, the corresponding light source interface channel starts overcurrent protection, where the typical value range of k is 0.3 to 0.6. This application sets conditions through the combination of luminous current and average current, corrects the PWM duty cycle, reduces the influence of interference and noise on the signal, provides accurate overcurrent protection, and improves the reliability of the digital light source controller.

[0082] The above content is only to illustrate the technical idea of this application and cannot be used to limit the protection scope of this application. Any changes made on the basis of the technical solution in accordance with the technical idea proposed in this application fall within the protection scope of the claims of this application.

[0083] In addition, unless clearly stated in the claims, the order of the processing elements and sequences, the use of numbers and letters, or the use of other names in this application are not used to limit the order of the processes and methods of this application. Although some currently considered useful embodiments are discussed through various examples in the above disclosure, it should be understood that such details only serve to illustrate the purpose. The appended claims are not limited to the disclosed embodiments. On the contrary, the claims are intended to cover all modifications and equivalent combinations that conform to the essence and scope of the embodiments of this application. For example, although the system components described above can be implemented by hardware devices, they can also be implemented only through software solutions, such as installing the described system on existing servers or mobile devices.

[0084] Similarly, it should be noted that in order to simplify the expression of the disclosure of this application and thus help the understanding of one or more embodiments, in the previous description of the embodiments of this application, sometimes multiple features are merged into one embodiment, drawing, or description thereof. However, this disclosure method does not mean that the features required by the object of this application are more than the features mentioned in the claims. In fact, the features of the embodiments are less than all the features of the above-disclosed single embodiment.

[0085] For each patent, patent application, patent application publication, and other materials cited in this application, such as articles, books, specifications, publications, documents, etc., their entire contents are hereby incorporated by reference into this application. This does not include application history documents that are inconsistent with or conflict with the content of this application, nor does it include documents that limit the broadest scope of the claims of this application (currently or subsequently appended to this application). It should be noted that if there are any inconsistencies or conflicts between the descriptions, definitions, and / or uses of terms in the supplementary materials of this application and the content described in this application, the descriptions, definitions, and / or uses of terms in this application shall prevail.

Claims

1. A digital light source controller, characterized in that, Including: A main control module, a PWM driving module, a switching module, a power supply module, a current detection module, and an N-channel light source interface; The power supply module is connected to the first interface of the light source interface; The switching module includes an MOS transistor. The switching module is connected to the second interface of the light source interface, and the switching module is used to control the on / off of the second interface; The current detection module includes a sampling resistor. The current detection module is electrically connected to the switching module and the main control module. The current detection module is used to convert the current signal passing through the switching module to obtain a sampling voltage, and send the sampling voltage to the main control module; The main control module, the PWM driving module, and the switching module are electrically connected in sequence; The main control module is configured to: obtain the sampling resistor value, sampling voltage value, and PWM duty cycle of each light source interface channel. The sampling resistor value is the resistance value of the sampling resistor in the current detection module, the sampling voltage value is the voltage value of the sampling voltage sent by the current detection module, and the sampling voltage value is the DC average value; Determine the luminous current and average current of the corresponding light source interface channel according to the sampling resistor value, the sampling voltage value, and the PWM duty cycle; Wherein: The calculation formula of the luminous current is: The calculation formula of the average current is: When the luminous current is greater than k times the maximum continuous operating current of the MOS transistor, or when the average current is greater than 1.1 times the rated current of the digital light source controller, the corresponding light source interface channel starts overcurrent protection; Wherein, k is a constant in the range of 0.3 to 0.6, and the non-linear correction formula of the PWM duty cycle is: where X is the brightness level (an integer from 0 to 255), is the rounding function.

2. A digital light source controller according to claim 1, characterized in that, The PWM driving module includes an MOS driving chip, and the MOS driving chip is electrically connected to the MOS transistor; The MOS driving chip is used to perform level conversion on the PWM control signal and provide a large current drive, and the large current drive is used to meet the drive requirements of the PWM control signal when the MOS transistor switches quickly.

3. A digital light source controller according to claim 1, characterized in that The current detection module further includes a second-order RC filter rectifier circuit; The second-order RC filter rectifier circuit is used to obtain a sampling voltage, and the sampling voltage is obtained by passing the PWM control signal voltage on the sampling resistor through the second-order RC filter rectifier circuit.

4. An overcurrent protection method, characterized in that, The overcurrent protection method includes: Obtain the sampling resistor value, sampling voltage value, and PWM duty cycle of each light source interface channel. The sampling resistor value is the resistance value of the sampling resistor in the current detection module, and the sampling voltage value is the voltage value of the sampling voltage sent by the current detection module; Determine the luminous current and average current of the corresponding light source interface channel according to the sampling resistor value, the sampling voltage value, and the PWM duty cycle; Wherein: The calculation formula of the luminous current is: The calculation formula of the average current is: When the luminous current is greater than k times the maximum continuous operating current of the MOS transistor, or when the average current is greater than 1.1 times the rated current of the digital light source controller, the corresponding light source interface channel starts overcurrent protection; Among them, k is a constant within the range of 0.3 to 0.6, and the non-linear correction formula for the PWM duty cycle is as follows: where X is the brightness level (an integer from 0 to 255), is the rounding function.

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