WO2022206030A1 - Linear led driving circuit, power switch detection method, and dimming control method - Google Patents

Linear led driving circuit, power switch detection method, and dimming control method Download PDF

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WO2022206030A1
WO2022206030A1 PCT/CN2021/138248 CN2021138248W WO2022206030A1 WO 2022206030 A1 WO2022206030 A1 WO 2022206030A1 CN 2021138248 W CN2021138248 W CN 2021138248W WO 2022206030 A1 WO2022206030 A1 WO 2022206030A1
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addition
power switch
module
voltage
subtraction counter
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PCT/CN2021/138248
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French (fr)
Chinese (zh)
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刘军
李国成
吴泉清
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华润微集成电路(无锡)有限公司
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    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
    • H05B45/30—Driver circuits
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
    • H05B45/10—Controlling the intensity of the light
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
    • H05B45/30—Driver circuits
    • H05B45/345—Current stabilisation; Maintaining constant current

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  • the power switch detection module further includes a parameter detection module, a timing module and a mode selection module, wherein:
  • the first input end of the second drive unit is connected to the compensation voltage generating circuit, the second input end of the second drive unit is connected to the output end of the bus voltage detection module, and the output end of the second drive unit connecting the grid of the second power switch tube;
  • the addition and subtraction counter when the addition and subtraction counter performs a subtraction operation, the charging current of the electrolytic capacitor in the linear LED driving circuit is reduced; when the addition and subtraction counter performs an addition operation, the charging current of the electrolytic capacitor is increased. .
  • the driving module 3 includes at least one driving sub-module, and the driving sub-module includes an LED lamp segment, a first power switch tube, a first sampling unit, a reference voltage generating unit and a first driving unit.
  • the positive pole of the segment is connected to the output end of the power input module 1, and the negative pole is connected to the drain of the first power switch tube, and the source of the first power switch tube is grounded via the first sampling unit; the reference voltage
  • the input end of the generating unit is connected to the power switch detection module 4, the output end is connected to the first input end of the first drive unit; the second input end of the first drive unit is connected to the source of the first power switch tube pole, and the output end is connected to the gate of the first power switch tube.
  • the linear LED driving circuit includes a plurality of the driving sub-modules
  • at least two of the driving sub-modules may share the reference voltage generating unit.
  • the forward input terminal of the first driving unit is connected to the reference voltage generating unit, and the reverse input terminal is connected to the source of the first power switch tube.
  • the device realizes the connection interchange between the input signal of the first driving unit and the input terminal, and only needs to be able to realize the corresponding driving function, which is not limited to this embodiment.
  • the charging current of the electrolytic capacitor Co decreases, reducing the loss of the power switch Q3 to improve the efficiency.
  • the electrolytic capacitor Co discharges to maintain the LED current constant current.
  • the addition and subtraction counter By detecting the voltage of the OUTx terminal (such as the OUT1 terminal or OUT2 terminal), the addition and subtraction counter generates a control signal to control the charging and discharging current of the electrolytic capacitor Co, so that the OUTx voltage maintains a suitable low value and maintains the LEDx (such as LED1 or LED2)
  • the loss of the power switch Q1 and the power switch Q2 is minimized, the system efficiency is improved, and the output has no flicker.
  • the power switch detection method of the linear LED drive circuit includes: timing the duration of the addition overflow signal of the addition and subtraction counter, and when the duration of the addition overflow signal of the addition and subtraction counter exceeds a preset value, determine The power switch SW is turned off.
  • the reference voltage provided by the reference voltage generating unit in the linear LED driving circuit is reduced; when the addition and subtraction counter overflows, the reference voltage is increased.
  • the reference voltage provided by the reference voltage generation unit in the linear LED driving circuit is reduced.
  • step (2) If yes, lower the benchmark, if not, then return to above-mentioned step (2);

Abstract

The present invention provides a linear LED driving circuit, a power switch detection method and a dimming control method. The linear LED driving circuit comprises a power input module (1), a power supply module (2), at least one driving module (3) and a power switch detection module (4). According to the present invention, power switch state detection and LED working state switching control are performed by means of an overflow signal of an addition/subtraction counter; when a negative electrode voltage of an LED lamp segment is lower than a certain value, the addition/subtraction counter generates an addition overflow signal, the reference is reduced, and timing is performed on the addition overflow signal to realize the power switch state detection and the LED working state switching control. The present invention is not affected by electric leakage and ignition of a power switch, and can reliably realize detection. By means of the processing of reducing the reference, an output at a low input voltage still has no strobe, and can still achieve the power switch state detection and LED working state switching, thereby avoiding the problem of false triggering by an input occurring when a high voltage is reduced to a low voltage. There is no need to add any element to the outside of a system, such that the system is simplified and system cost is reduced.

Description

一种线性LED驱动电路、电源开关检测方法及调光控制方法A linear LED drive circuit, power switch detection method and dimming control method
相关申请的交叉引用CROSS-REFERENCE TO RELATED APPLICATIONS
本申请要求于2021年4月1日提交中国专利局、申请号为202110353326.2、发明名称为“一种线性LED驱动电路、电源开关检测方法及调光控制方法”的中国专利申请的优先权，其全部内容通过引用结合在本申请中。This application claims the priority of the Chinese patent application filed on April 1, 2021 with the application number of 202110353326.2 and the invention titled "A linear LED drive circuit, power switch detection method and dimming control method". The entire contents of this application are incorporated by reference.
技术领域technical field
本发明属于LED驱动领域，涉及一种线性LED驱动电路、电源开关检测方法及调光控制方法。The invention belongs to the field of LED driving, and relates to a linear LED driving circuit, a power switch detection method and a dimming control method.
背景技术Background technique
在线性发光二极管(LED)驱动开关调光的应用中，通过检测开关SW的动作来做分段式调光的切换，例如第一次开为100％亮度，然后开关一次变为50％亮度，再次开关变为另一个设定的亮度或者循环第一次的亮度(或者控制多路LED驱动就可以实现调色的功能)，其中，图1显示为一种能实现上述调光控制的LED驱动电路。In the application of linear light emitting diode (LED) driving switch dimming, the switching of segmented dimming is performed by detecting the action of the switch SW. Switch again to another set brightness or cycle the brightness for the first time (or control multiple LED drivers to achieve the function of color grading). Among them, Figure 1 shows an LED driver that can realize the above dimming control. circuit.
随着企业资源规划系统(ERP)标准的推行，LED驱动在满足功率因数PF、谐波、效率等要求下还增加了对频闪的要求，对此，线性LED驱动也做了一些优化，如图2所示，显示为另一种LED驱动电路，其增加二极管D1将去频闪电容Co与输入母线电压LN隔离，防止开关关断后Co剩余的电压干扰母线电压的检测，输入母线电压LN经过开关检测模块判断开关SW的开关状态，然后再控制LED驱动模块进行开关调光或调色的处理。With the implementation of the enterprise resource planning system (ERP) standard, the LED driver has also increased the requirements for stroboscopic while meeting the requirements of power factor PF, harmonics, efficiency, etc. In this regard, the linear LED driver has also made some optimizations, such as As shown in Figure 2, it is another LED drive circuit, which adds a diode D1 to isolate the de-stroboscopic capacitor Co from the input bus voltage LN to prevent the remaining voltage of Co from interfering with the detection of the bus voltage after the switch is turned off. The input bus voltage LN The switch detection module judges the switch state of the switch SW, and then controls the LED drive module to perform switch dimming or color tone processing.
在图2的应用中，如果开关SW有漏电，开关检测电压LN可能会无法下降到检测值，导致开关检测失效。其次开关SW在接通和关断瞬间会有一些打火现象，导致母线电压有比较大的抖动，也会导致开关检测的误动作，在多灯一起工作时就会出现工作模式不一致的问题。此外还需要一个额外的二极管D1做隔离，增加了系统成本。In the application of FIG. 2 , if the switch SW has leakage, the switch detection voltage LN may not be able to drop to the detection value, resulting in failure of the switch detection. Secondly, the switch SW will have some sparks at the moment of turning on and off, which will cause the bus voltage to have a relatively large jitter, and will also cause the malfunction of the switch detection. When multiple lights work together, there will be a problem of inconsistent working modes. In addition, an additional diode D1 is required for isolation, which increases the system cost.
因此，如何可靠地检测电源开关的开关状态并降低系统成本，成为本领域技术人员亟待解决的一个重要技术问题。Therefore, how to reliably detect the switching state of the power switch and reduce the system cost has become an important technical problem to be solved urgently by those skilled in the art.
发明内容SUMMARY OF THE INVENTION
鉴于以上所述现有技术的缺点，本发明的目的在于提供一种线性LED驱动电路、电源 开关检测方法及调光控制方法，用于解决现有技术中电源开关检测失败、误动作及系统成本较高的问题。In view of the above-mentioned shortcomings of the prior art, the purpose of the present invention is to provide a linear LED driving circuit, a power switch detection method and a dimming control method, which are used to solve the power switch detection failure, malfunction and system cost in the prior art higher problem.
为实现上述目的及其他相关目的，本发明提供一种线性LED驱动电路，包括：In order to achieve the above purpose and other related purposes, the present invention provides a linear LED drive circuit, comprising:
电源输入模块，输入端串联一电源开关，用于提供直流母线电压；Power input module, the input terminal is connected in series with a power switch to provide DC bus voltage;
供电模块，连接所述电源输入模块的输出端，用于提供工作电压；a power supply module, connected to the output end of the power supply input module, and used for providing a working voltage;
至少一驱动模块，连接于所述电源输入模块的输出端，用于驱动LED发光；at least one driving module, connected to the output end of the power input module, for driving the LED to emit light;
电源开关检测模块，连接所述驱动模块并包括加减法计数器，基于所述加减法计数器的加法溢出信号的持续时间判断所述电源开关的导通或关断情况以进行调光控制。The power switch detection module is connected to the driving module and includes an addition and subtraction counter, and judges the on or off condition of the power switch based on the duration of the addition overflow signal of the addition and subtraction counter to perform dimming control.
可选地，所述驱动模块包括至少一驱动子模块，所述驱动子模块包括LED灯段、第一功率开关管、第一采样单元、参考电压产生单元及第一驱动单元，其中：Optionally, the driving module includes at least one driving sub-module, and the driving sub-module includes an LED lamp segment, a first power switch tube, a first sampling unit, a reference voltage generating unit and a first driving unit, wherein:
所述LED灯段的正极连接所述电源输入模块的输出端，负极连接所述第一功率开关管的漏极，所述第一功率开关管的源极经由所述第一采样单元接地；The positive pole of the LED lamp segment is connected to the output end of the power input module, the negative pole is connected to the drain of the first power switch tube, and the source of the first power switch tube is grounded via the first sampling unit;
所述参考电压产生单元的输入端连接所述电源开关检测模块，输出端连接所述第一驱动单元的第一输入端；The input end of the reference voltage generating unit is connected to the power switch detection module, and the output end is connected to the first input end of the first driving unit;
所述第一驱动单元的第二输入端连接所述第一功率开关管的源极，输出端连接所述第一功率开关管的栅极。The second input end of the first driving unit is connected to the source of the first power switch tube, and the output end is connected to the gate of the first power switch tube.
可选地，所述驱动模块包括多个所述驱动子模块，至少两个所述驱动子模块共用一所述参考电压产生单元。Optionally, the driving module includes a plurality of the driving sub-modules, and at least two of the driving sub-modules share the reference voltage generating unit.
可选地，所述电源开关检测模块还包括参数检测模块、计时模块及模式选择模块，其中：Optionally, the power switch detection module further includes a parameter detection module, a timing module and a mode selection module, wherein:
所述参数检测模块连接所述驱动模块及所述加减法计数器，用于检测所述驱动模块的预设参数并控制所述加减法计数器进行加法或减法运算；The parameter detection module is connected to the drive module and the addition/subtraction counter, and is used for detecting preset parameters of the drive module and controlling the addition/subtraction counter to perform addition or subtraction operations;
所述计时模块连接所述加减法计数器的计数溢出端以对所述加减法计数器的加法溢出信号的持续时间进行计时；The timing module is connected to the counting overflow terminal of the addition and subtraction counter to time the duration of the addition overflow signal of the addition and subtraction counter;
所述模式选择模块连接所述计时模块及所述参考电压产生单元，用于当加法溢出信号持续计时超过预设值时产生开关状态切换信号。The mode selection module is connected to the timing module and the reference voltage generating unit, and is used for generating a switch state switching signal when the addition overflow signal continues to clock over a preset value.
可选地，所述加减法计数器的计数溢出端还连接所述参考电压产生单元以根据溢出信号控制所述参考电压产生单元调整参考电压的值。Optionally, the counting overflow terminal of the addition and subtraction counter is further connected to the reference voltage generating unit to control the reference voltage generating unit to adjust the value of the reference voltage according to the overflow signal.
可选地，所述参数检测模块包括电压检测模块，所述电压检测模块连接所述LED灯段的负极及所述加减法计数器，以基于所述LED灯段的负极电压控制所述加减法计数器进行加法或减法运算。Optionally, the parameter detection module includes a voltage detection module, the voltage detection module is connected to the negative electrode of the LED lamp segment and the addition and subtraction counter, so as to control the addition and subtraction based on the negative electrode voltage of the LED lamp segment. The addition or subtraction operation is performed on the addition or subtraction counter.
可选地，所述电压检测模块还连接所述第一功率开关管的栅极及所述模式选择模块。Optionally, the voltage detection module is further connected to the gate of the first power switch tube and the mode selection module.
可选地，所述参数检测模块包括源极电流检测模块，所述源极电流检测模块连接所述第一功率开关管的源极及所述加减法计数器，以基于所述第一功率开关管的源极电流控制所述加减法计数器进行加法或减法运算。Optionally, the parameter detection module includes a source current detection module, the source current detection module is connected to the source of the first power switch tube and the addition and subtraction counter, so as to be based on the first power switch. The source current of the tube controls the addition and subtraction counter to perform addition or subtraction operations.
可选地，所述线性LED驱动电路还包括电解电容及充电电流控制模块，其中：Optionally, the linear LED drive circuit further includes an electrolytic capacitor and a charging current control module, wherein:
所述电解电容的上极板连接LED灯段的正极，用于在所述母线电压小于所述电解电容上的电压时向所述LED灯段放电；The upper plate of the electrolytic capacitor is connected to the positive electrode of the LED lamp segment, and is used for discharging to the LED lamp segment when the busbar voltage is lower than the voltage on the electrolytic capacitor;
所述充电电流控制模块连接所述加减法计数器、所述电源输入模块的输出端及所述电解电容的下极板，基于所述加减法计数器的控制信号及所述电源输入模块的输出电压调整所述电解电容的充放电电流。The charging current control module is connected to the addition and subtraction counter, the output end of the power input module and the lower plate of the electrolytic capacitor, based on the control signal of the addition and subtraction counter and the output of the power input module The voltage adjusts the charging and discharging current of the electrolytic capacitor.
可选地，所述充电电流控制模块包括母线电压检测模块、补偿电压产生电路、数模转换单元、第二驱动单元、第二功率开关管、第二采样单元及第三采样单元，其中：Optionally, the charging current control module includes a bus voltage detection module, a compensation voltage generating circuit, a digital-to-analog conversion unit, a second driving unit, a second power switch tube, a second sampling unit and a third sampling unit, wherein:
所述母线电压检测模块连接所述电源输入模块的输出端以对所述母线电压进行检测；The busbar voltage detection module is connected to the output end of the power input module to detect the busbar voltage;
所述第二驱动单元的第一输入端连接所述补偿电压产生电路，所述第二驱动单元的第二输入端连接所述母线电压检测模块的输出端，所述第二驱动单元的输出端连接所述第二功率开关管的栅极；The first input end of the second drive unit is connected to the compensation voltage generating circuit, the second input end of the second drive unit is connected to the output end of the bus voltage detection module, and the output end of the second drive unit connecting the grid of the second power switch tube;
所述数模转换单元连接于所述补偿电压产生电路与所述加减法计数器之间；The digital-to-analog conversion unit is connected between the compensation voltage generating circuit and the addition and subtraction counter;
所述第二功率开关管的漏极连接所述电解电容的下极板，源极经由所述第二采样单元与所述第二驱动单元的第二输入端连接，并经由所述第三采样单元接地。The drain of the second power switch tube is connected to the lower plate of the electrolytic capacitor, the source is connected to the second input end of the second driving unit via the second sampling unit, and is connected to the second input end of the second driving unit via the third sampling unit Unit is grounded.
本发明还提供一种线性LED驱动电路的电源开关检测方法，包括：对加减法计数器的加法溢出信号的持续时间进行计时，当加减法计数器的加法溢出信号的持续时间超过预设值时，判定电源开关关断。The present invention also provides a power switch detection method for a linear LED drive circuit, comprising: timing the duration of the addition overflow signal of the addition and subtraction counter, and when the duration of the addition overflow signal of the addition and subtraction counter exceeds a preset value , it is determined that the power switch is turned off.
可选地，检测所述线性LED驱动电路中LED灯段的负极电压，当所述LED灯段的负极电压高于预设值时，所述加减法计数器进行减法运算；当所述LED灯段的负极电压低于预设值时，所述加减法计数器进行加法运算。Optionally, detect the negative voltage of the LED lamp segment in the linear LED drive circuit, and when the negative voltage of the LED lamp segment is higher than a preset value, the addition and subtraction counter performs a subtraction operation; when the LED lamp When the negative voltage of the segment is lower than the preset value, the addition and subtraction counter performs addition operation.
可选地，当所述加减法计数器进行减法运算时，降低所述线性LED驱动电路中电解电容的充电电流；当所述加减法计数器进行加法运算时，增加所述电解电容的充电电流。Optionally, when the addition and subtraction counter performs a subtraction operation, the charging current of the electrolytic capacitor in the linear LED driving circuit is reduced; when the addition and subtraction counter performs an addition operation, the charging current of the electrolytic capacitor is increased. .
可选地，当所述加减法计数器产生加法计数溢出时，减小所述线性LED驱动电路中参考电压产生单元提供的参考电压；当所述加减法计数器产生减法计数溢出时，提高所述线性LED驱动电路中参考电压产生单元提供的参考电压。Optionally, when the addition and subtraction counter overflows, the reference voltage provided by the reference voltage generating unit in the linear LED driving circuit is reduced; when the addition and subtraction counter overflows, the reference voltage is increased. The reference voltage provided by the reference voltage generating unit in the linear LED driving circuit.
本发明还提供一种线性LED驱动电路的调光控制方法，采用如上任意一项所述的线性 LED驱动电路的电源开关检测方法检测电源开关的状态，当检测到电源开关关断时，产生开关状态切换信号，并记忆当前工作状态。The present invention also provides a dimming control method for a linear LED drive circuit. The power switch detection method for a linear LED drive circuit described in any one of the above is used to detect the state of the power switch, and when it is detected that the power switch is turned off, a switch is generated. State switching signal, and memorize the current working state.
可选的，当所述线性LED驱动电路中电解电容完全放电之前，若所述电源开关打开，电源接通后所述线性LED驱动电路中LED灯段切换进入下个工作状态；当所述电解电容完全放电后，对内部工作状态清零，再次上电时所述LED灯段进入默认工作状态。Optionally, before the electrolytic capacitor in the linear LED driving circuit is completely discharged, if the power switch is turned on, the LED lamp segment in the linear LED driving circuit switches to the next working state after the power is turned on; After the capacitor is completely discharged, the internal working state is cleared, and the LED light segment enters the default working state when the power is turned on again.
可选地，根据相应工作状态输出对应的参考电压以实现调光操作。Optionally, the corresponding reference voltage is output according to the corresponding working state to realize the dimming operation.
如上所述，本发明的线性LED驱动电路、电源开关检测方法及调光控制方法通过加减法计数器溢出信号来做电源开关状态检测及LED工作状态切换控制，当LED灯段的负极电压低于一定值时加减法计数器产生加法溢出信号，降低基准，并对加法溢出信号进行计时来实现电源开关状态检测及LED工作状态切换控制。本发明不受电源开关漏电及打火的影响，可以可靠的实现检测。经过降基准的处理，低输入电压时输出仍然无频闪，并仍能实现电源开关状态的检测和LED工作状态的切换，避免了输入从高电压降低到低电压时会误触发的问题。系统外部无需增加任何元件，使系统最简化并降低系统成本。As mentioned above, the linear LED drive circuit, power switch detection method and dimming control method of the present invention perform power switch state detection and LED working state switching control by adding and subtracting counter overflow signals. When the negative voltage of the LED lamp segment is lower than At a certain value, the addition and subtraction counter generates an addition overflow signal, lowers the reference, and time the addition overflow signal to realize the power switch state detection and LED working state switching control. The present invention is not affected by leakage and ignition of the power switch, and can reliably realize detection. After the process of lowering the reference, the output still has no flicker when the input voltage is low, and the detection of the power switch state and the switching of the LED working state can still be realized, avoiding the problem of false triggering when the input is reduced from high voltage to low voltage. There is no need to add any components outside the system, which simplifies the system and reduces the system cost.
附图说明Description of drawings
图1显示为一种能实现分段式调光切换的LED驱动电路的示意图。FIG. 1 is a schematic diagram of an LED driving circuit capable of realizing segmented dimming switching.
图2显示为一种能够防止电容剩余电压干扰母线电压检测的LED驱动电路的示意图。FIG. 2 is a schematic diagram of an LED driving circuit that can prevent the residual voltage of the capacitor from interfering with the detection of the bus voltage.
图3显示为一种不含隔离二极管的LED驱动电路的示意图。FIG. 3 shows a schematic diagram of an LED driving circuit without an isolation diode.
图4显示为本发明的线性LED驱动电路的示意图。FIG. 4 is a schematic diagram of the linear LED driving circuit of the present invention.
图5显示为通过环路加减法计数器溢出信号来做电源开关检测及切换控制的一种工作流程图。Fig. 5 shows a working flow chart of the power switch detection and switching control through the loop addition and subtraction counter overflow signal.
元件标号说明Component label description
1                      电源输入模块1 Power input module
2                      供电模块2 Power supply module
3                      驱动模块3 Drive module
4                      电源开关检测模块4 Power switch detection module
5                      充电电流控制模块5 Charge current control module
具体实施方式Detailed ways
以下通过特定的具体实例说明本发明的实施方式，本领域技术人员可由本说明书所揭 露的内容轻易地了解本发明的其他优点与功效。本发明还可以通过另外不同的具体实施方式加以实施或应用，本说明书中的各项细节也可以基于不同观点与应用，在没有背离本发明的精神下进行各种修饰或改变。The embodiments of the present invention are described below through specific specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.
如图3所示，显示为一种LED驱动电路，其改变检测方式，不再检测母线电压，而是通过开关管的漏极电压或电流来判断开关SW的动作方式来去掉隔离二极管，降低系统成本。在图3的应用中，开关SW关断后，母线HV电压会下降，导致OUTx电压也会下降，LED无法恒流后CSx电流也会同时减小，因此可以通过OUTx电压或CSx电流来判断SW的开关状态。但是由于OUTx和CSx必须设置一个阈值来判定，因此当输入电压比较低时，例如，正好维持在OUTx或CSx的阈值附近时，就会导致误动作，如果低于阈值就会无法实现开关状态的切换，无法达到理想的工作状态，这种情况经常出现在较高的输入电压降到较低的输入电压时。如果OUTx电压或CSx电流高于阈值时，此时就会切换进入下个工作状态，即使开关SW并没有被关断。本发明通过新的系统设计，基于所述加减法计数器的加法溢出信号的持续时间判断所述电源开关的导通或关断情况以进行调光控制，可以可靠地检测电源开关的开关状态并降低系统成本。下面通过具体的实施例来详述本发明的技术方案。As shown in Figure 3, it is shown as an LED drive circuit, which changes the detection method, no longer detects the bus voltage, but judges the action mode of the switch SW through the drain voltage or current of the switch tube to remove the isolation diode and reduce the system. cost. In the application of Figure 3, after the switch SW is turned off, the bus HV voltage will drop, resulting in a drop in the OUTx voltage, and the CSx current will also decrease after the LED cannot be constant current. Therefore, the SW can be judged by the OUTx voltage or CSx current. switch status. However, since OUTx and CSx must set a threshold to determine, when the input voltage is relatively low, for example, when it is maintained near the threshold of OUTx or CSx, it will cause malfunction, and if it is lower than the threshold, the switching state will not be realized. switching, the ideal operating state cannot be achieved, which often occurs when a higher input voltage drops to a lower input voltage. If the OUTx voltage or CSx current is higher than the threshold, it will switch to the next operating state at this time, even if the switch SW is not turned off. Through a new system design, the present invention judges the on or off condition of the power switch based on the duration of the addition overflow signal of the addition and subtraction counter to perform dimming control, and can reliably detect the switch state of the power switch and Reduce system costs. The technical solutions of the present invention will be described in detail below through specific embodiments.
实施例一Example 1
请参阅图4，本实施例提供一种线性LED驱动电路，包括电源输入模块1、供电模块2、至少一驱动模块3及电源开关检测模块4。Referring to FIG. 4 , this embodiment provides a linear LED driving circuit, including a power input module 1 , a power supply module 2 , at least one driving module 3 and a power switch detection module 4 .
具体的，所述电源输入模块1接收输入电源(AC输入)，将所述输入电源(AC输入)转化为直流母线电压HV，所述电源输入模块1的输入端串联一电源开关SW。Specifically, the power input module 1 receives input power (AC input), converts the input power (AC input) into a DC bus voltage HV, and an input terminal of the power input module 1 is connected in series with a power switch SW.
作为示例，所述电源输入模块1的第一交流输入端连接零线，第二交流输入端经由所述电源开关SW连接相线。As an example, the first AC input end of the power input module 1 is connected to the neutral line, and the second AC input end is connected to the phase line via the power switch SW.
作为示例，所述电源输入模块1包括整流桥结构BD1及保险丝F1，所述整流桥结构BD1包括并联的两组二极管组，各二极管组包括串联的两个二极管，所述输入电源(AC输入)经所述保险丝F1后连接于各二极管组的两个二极管之间。所述母线电压HV为正弦电压整流后的整流电压。As an example, the power input module 1 includes a rectifier bridge structure BD1 and a fuse F1, the rectifier bridge structure BD1 includes two groups of diode groups connected in parallel, each diode group includes two diodes connected in series, and the input power supply (AC input) After passing through the fuse F1, it is connected between the two diodes of each diode group. The bus voltage HV is a rectified voltage after sinusoidal voltage rectification.
具体的，供电模块2连接所述电源输入模块1的输出端，基于所述母线电压HV为所述线性LED驱动电路提供工作电压VDD。Specifically, the power supply module 2 is connected to the output end of the power supply input module 1, and provides the linear LED driving circuit with an operating voltage VDD based on the bus voltage HV.
具体的，所述驱动模块3连接于所述电源输入模块1的输出端，用于驱动LED发光。Specifically, the driving module 3 is connected to the output end of the power input module 1 for driving the LED to emit light.
作为示例，所述驱动模块3包括至少一驱动子模块，所述驱动子模块包括LED灯段、 第一功率开关管、第一采样单元、参考电压产生单元及第一驱动单元，所述LED灯段的正极连接所述电源输入模块1的输出端，负极连接所述第一功率开关管的漏极，所述第一功率开关管的源极经由所述第一采样单元接地；所述参考电压产生单元的输入端连接所述电源开关检测模块4，输出端连接所述第一驱动单元的第一输入端；所述第一驱动单元的第二输入端连接所述第一功率开关管的源极，输出端连接所述第一功率开关管的栅极。As an example, the driving module 3 includes at least one driving sub-module, and the driving sub-module includes an LED lamp segment, a first power switch tube, a first sampling unit, a reference voltage generating unit and a first driving unit. The positive pole of the segment is connected to the output end of the power input module 1, and the negative pole is connected to the drain of the first power switch tube, and the source of the first power switch tube is grounded via the first sampling unit; the reference voltage The input end of the generating unit is connected to the power switch detection module 4, the output end is connected to the first input end of the first drive unit; the second input end of the first drive unit is connected to the source of the first power switch tube pole, and the output end is connected to the gate of the first power switch tube.
作为示例，所述第一采样单元包括但不限于采样电阻Rcs，所述第一驱动单元包括但不限于运算放大器OP。As an example, the first sampling unit includes but is not limited to a sampling resistor Rcs, and the first driving unit includes but is not limited to an operational amplifier OP.
作为示例，当所述线性LED驱动电路包括多个所述驱动子模块时，可至少有两个所述驱动子模块共用一所述参考电压产生单元。As an example, when the linear LED driving circuit includes a plurality of the driving sub-modules, at least two of the driving sub-modules may share the reference voltage generating unit.
如图4所示，本实施例中，所述驱动模块3包括第一驱动子模块与第二驱动子模块，所述第一驱动子模块包括LED灯段LED1、功率开关管Q1、采样单元Rcs1、参考电压产生单元及驱动单元OP1，其中，LED灯段LED1的正极连接所述电源输入模块1的输出端，负极连接功率开关管Q1的漏极，功率开关管Q1的源极经由采样单元Rcs1接地；所述第二驱动子模块包括LED灯段LED2、功率开关管Q2、采样单元Rcs2、参考电压产生单元及驱动单元OP2，其中，LED灯段LED2的正极连接所述电源输入模块1的输出端，负极连接功率开关管Q2的漏极，功率开关管Q2的源极经由采样单元Rcs2接地。As shown in FIG. 4 , in this embodiment, the driving module 3 includes a first driving sub-module and a second driving sub-module, and the first driving sub-module includes an LED lamp segment LED1 , a power switch tube Q1 , and a sampling unit Rcs1 , a reference voltage generating unit and a driving unit OP1, wherein the positive pole of the LED lamp segment LED1 is connected to the output end of the power input module 1, the negative pole is connected to the drain of the power switch tube Q1, and the source of the power switch tube Q1 is connected via the sampling unit Rcs1 Ground; the second driving sub-module includes LED lamp segment LED2, power switch tube Q2, sampling unit Rcs2, reference voltage generating unit and driving unit OP2, wherein the positive pole of LED lamp segment LED2 is connected to the output of the power input module 1 terminal, the negative pole is connected to the drain of the power switch tube Q2, and the source of the power switch tube Q2 is grounded via the sampling unit Rcs2.
作为示例，所述第一驱动单元的正向输入端连接所述参考电压产生单元，反向输入端连接所述第一功率开关管的源极，在实际使用中，可通过增加反相器等器件实现所述第一驱动单元的输入信号与输入端的连接互换，能实现相应的驱动功能即可，不以本实施例为限。As an example, the forward input terminal of the first driving unit is connected to the reference voltage generating unit, and the reverse input terminal is connected to the source of the first power switch tube. The device realizes the connection interchange between the input signal of the first driving unit and the input terminal, and only needs to be able to realize the corresponding driving function, which is not limited to this embodiment.
需要说明的是，所述驱动模块3的具体结构可根据需要进行设定，不限于本实施例所列举的架构。It should be noted that, the specific structure of the driving module 3 can be set as required, and is not limited to the structure listed in this embodiment.
具体的，所述电源开关检测模块4连接所述驱动模块3并包括加减法计数器，基于所述加减法计数器的加法溢出信号的持续时间判断所述电源开关SW的导通或关断情况以进行调光控制。Specifically, the power switch detection module 4 is connected to the drive module 3 and includes an addition and subtraction counter, and judges whether the power switch SW is turned on or off based on the duration of the addition overflow signal of the addition and subtraction counter. for dimming control.
作为示例，所述电源开关检测模块4还包括参数检测模块、计时模块及模式选择模块，其中：所述参数检测模块连接所述驱动模块3及所述加减法计数器，用于检测所述驱动模块3的预设参数并控制所述加减法计数器进行加法或减法运算；所述计时模块连接所述加减法计数器的计数溢出端以对所述加减法计数器的加法溢出信号的持续时间进行计时；所述模式选择模块连接所述计时模块及所述参考电压产生模块，用于当加法溢出信号持续计时超过预设值时产生开关状态切换信号。As an example, the power switch detection module 4 further includes a parameter detection module, a timing module and a mode selection module, wherein: the parameter detection module is connected to the driving module 3 and the addition and subtraction counter for detecting the driving The preset parameters of module 3 and control the addition and subtraction counters to perform addition or subtraction operations; the timing module is connected to the counting overflow end of the addition and subtraction counters to measure the duration of the addition overflow signal of the addition and subtraction counters timing; the mode selection module is connected to the timing module and the reference voltage generating module, and is used for generating a switch state switching signal when the addition overflow signal continues to time a preset value.
如图4所示，本实施例中，所述参数检测模块采用电压检测模块，所述电压检测模块连接所述LED灯段的负极及所述加减法计数器，以基于所述LED灯段的负极电压控制所述加减法计数器进行加法或减法运算。本实施例中，所述电压检测模块还连接所述第一功率开关管的栅极及所述模式选择模块。As shown in FIG. 4 , in this embodiment, the parameter detection module adopts a voltage detection module, and the voltage detection module is connected to the negative pole of the LED lamp segment and the addition and subtraction counter, so as to be based on the The negative electrode voltage controls the addition and subtraction counter to perform addition or subtraction operations. In this embodiment, the voltage detection module is further connected to the gate of the first power switch tube and the mode selection module.
在另一实施例中，所述参数检测模块也可采用源极电流检测模块，所述源极电流检测模块连接所述第一功率开关管的源极及所述加减法计数器，以基于所述第一功率开关管的源极电流控制所述加减法计数器进行加法或减法运算。In another embodiment, the parameter detection module may also use a source current detection module, the source current detection module is connected to the source of the first power switch tube and the addition and subtraction counter, so as to be based on the The source current of the first power switch tube controls the addition and subtraction counter to perform addition or subtraction operations.
作为示例，所述加减法计数器的计数溢出端还连接所述参考电压产生单元以根据溢出信号控制所述参考电压产生单元调整参考电压的值。As an example, the counting overflow terminal of the up-subtraction counter is further connected to the reference voltage generating unit to control the reference voltage generating unit to adjust the value of the reference voltage according to the overflow signal.
作为示例，所述线性LED驱动电路还包括电解电容Co及充电电流控制模块5，其中：所述电解电容Co的上极板连接LED灯段的正极，用于在所述母线电压HV小于所述电解电容Co上的电压时向所述LED灯段放电；所述充电电流控制模块5连接所述加减法计数器、所述电源输入模块1的输出端及所述电解电容的下极板，基于所述加减法计数器的控制信号及所述电源输入模块1的输出电压调整所述电解电容Co的充放电电流。As an example, the linear LED driving circuit further includes an electrolytic capacitor Co and a charging current control module 5, wherein: the upper plate of the electrolytic capacitor Co is connected to the anode of the LED lamp segment, for when the bus voltage HV is lower than the The voltage on the electrolytic capacitor Co is discharged to the LED lamp segment; the charging current control module 5 is connected to the addition and subtraction counter, the output end of the power input module 1 and the lower plate of the electrolytic capacitor, based on The control signal of the addition and subtraction counter and the output voltage of the power input module 1 adjust the charging and discharging current of the electrolytic capacitor Co.
作为示例，所述充电电流控制模块5包括母线电压检测模块、补偿电压产生电路、数模转换单元、第二驱动单元、第二功率开关管Q3、第二采样单元及第三采样单元。本实施例中，所述第二驱动单元采用运算放大器OP3，所述第二采样单元采用采样电阻Rs1，所述第三采样单元采用采样电阻Rs2。As an example, the charging current control module 5 includes a bus voltage detection module, a compensation voltage generating circuit, a digital-to-analog conversion unit, a second driving unit, a second power switch Q3, a second sampling unit and a third sampling unit. In this embodiment, the second driving unit adopts an operational amplifier OP3, the second sampling unit adopts a sampling resistor Rs1, and the third sampling unit adopts a sampling resistor Rs2.
具体的，如图4所示，所述母线电压检测模块连接所述电源输入模块1的输出端以对所述母线电压HV进行检测；所述运算放大器OP3的正向输入端连接所述补偿电压产生电路，所述运算放大器OP3的负向输入端连接所述母线电压检测模块的输出端，所述运算放大器OP3的输出端连接所述第二功率开关管Q3的栅极；所述数模转换单元连接于所述补偿电压产生电路与所述加减法计数器之间；所述第二功率开关管Q3的漏极连接所述电解电容Co的下极板，源极经由所述采样电阻Rs1与所述运算放大器OP3的第二输入端连接，并经由所述采样电阻Rs2接地。Specifically, as shown in FIG. 4 , the bus voltage detection module is connected to the output terminal of the power input module 1 to detect the bus voltage HV; the positive input terminal of the operational amplifier OP3 is connected to the compensation voltage generating circuit, the negative input terminal of the operational amplifier OP3 is connected to the output terminal of the bus voltage detection module, and the output terminal of the operational amplifier OP3 is connected to the gate of the second power switch tube Q3; the digital-to-analog conversion The unit is connected between the compensation voltage generating circuit and the addition and subtraction counter; the drain of the second power switch Q3 is connected to the lower plate of the electrolytic capacitor Co, and the source is connected to the sampling resistor Rs1 through the sampling resistor Rs1. The second input terminal of the operational amplifier OP3 is connected to the ground via the sampling resistor Rs2.
需要指出的是，在实际使用中，可通过增加反相器等器件实现所述第二驱动单元的输入信号与输入端的连接互换，能实现相应的驱动功能即可，不以本实施例为限。It should be pointed out that, in actual use, the connection between the input signal of the second driving unit and the input terminal can be realized by adding devices such as inverters, and the corresponding driving function can be realized. limit.
本实施例的线性LED驱动电路的工作原理如下：The working principle of the linear LED driving circuit of this embodiment is as follows:
当母线电压HV较高时，电解电容Co充电电流减小，减小功率开关管Q3的损耗以提高效率，输入电压低时电解电容Co放电，维持LED电流恒流。通过检测OUTx端(例如OUT1端或OUT2端)的电压，加减法计数器产生一个控制信号去控制电解电容Co的充 放电电流，使得OUTx电压保持合适的低值，维持LEDx(例如LED1或LED2)恒流的同时确保功率开关管Q1与功率开关管Q2的损耗最小，提高系统效率并且输出无频闪。When the bus voltage HV is high, the charging current of the electrolytic capacitor Co decreases, reducing the loss of the power switch Q3 to improve the efficiency. When the input voltage is low, the electrolytic capacitor Co discharges to maintain the LED current constant current. By detecting the voltage of the OUTx terminal (such as the OUT1 terminal or OUT2 terminal), the addition and subtraction counter generates a control signal to control the charging and discharging current of the electrolytic capacitor Co, so that the OUTx voltage maintains a suitable low value and maintains the LEDx (such as LED1 or LED2) At the same time of constant current, the loss of the power switch Q1 and the power switch Q2 is minimized, the system efficiency is improved, and the output has no flicker.
当母线电压HV比较低时，对应的OUTx电压也会比较低，加减法计数器会一直进行加法运算，增加电解电容Co的充电电流来维持LEDx电流恒流。当加减法计数器触发到加法溢出时，一方面加法溢出信号会减小参考电压产生单元产生的参考电压，降低LEDx输出电流来维持计数器的正常工作(如果电解电容Co的充电电流能满足减小的LEDx电流的消耗，此时进入正常工作后加法溢出信号会消失，在工频周期内不会一直做加法而是有加有减)，实现低压输入、而降输出电流并且无频闪的功能。另一方面溢出信号会经过计时模块进行计时，当加法溢出信号持续计时超过设定值时说明输出电流已经小到无法维持的状态，可以判断电源开关SW关断，进入开关切换的下一个工作状态。此时LED虽然无法导通，但是电解电容Co仍然有比较高的电压，可以维持芯片的工作，记忆住当前工作状态。在电解电容Co完全放电完之前如果电源开关SW打开，电源接通后LED就会切换进入下个导通状态，一旦电解电容Co完全放电后内部状态会清零，再次上电时系统会进入默认状态。When the bus voltage HV is relatively low, the corresponding OUTx voltage will also be relatively low, and the addition and subtraction counter will always perform addition operation to increase the charging current of the electrolytic capacitor Co to maintain the constant current of the LEDx current. When the addition and subtraction counter is triggered to the addition overflow, on the one hand, the addition overflow signal will reduce the reference voltage generated by the reference voltage generation unit, and reduce the LEDx output current to maintain the normal operation of the counter (if the charging current of the electrolytic capacitor Co can meet the reduction LEDx current consumption, the addition overflow signal will disappear after entering normal operation at this time, in the power frequency cycle, it will not be added all the time but there will be addition and subtraction), to realize the function of low-voltage input, lower output current and no stroboscopic . On the other hand, the overflow signal will be timed by the timing module. When the addition overflow signal continues to time and exceeds the set value, it means that the output current is too small to be maintained. It can be judged that the power switch SW is turned off and enters the next working state of switch switching. . At this time, although the LED cannot be turned on, the electrolytic capacitor Co still has a relatively high voltage, which can maintain the work of the chip and memorize the current working state. If the power switch SW is turned on before the electrolytic capacitor Co is completely discharged, the LED will switch to the next conduction state after the power is turned on. Once the electrolytic capacitor Co is completely discharged, the internal state will be cleared, and the system will enter the default state when the power is turned on again. state.
另外，只有当OUTx电压持续为低时加减法计数器才会一直产生加法溢出信号，经过持续计时一段设定的时间后才会产生开关状态切换信号，因此只有当电源开关SW完全关断后才会触发开关状态切换的动作，可以有效避免电源开关SW打火或漏电造成的干扰。由于加法溢出信号还有一个降基准的动作，因此即使输入电压低时OUTx电压维持在一个低电平而不是完全掉电的情况下，加法溢出信号不会一直持续，而会不断的触发直到环路进入平衡状态，没有持续计时的信号从而避免开关状态切换的误触发。In addition, the addition and subtraction counter will always generate the addition overflow signal only when the OUTx voltage continues to be low, and the switch state switching signal will be generated only after the continuous timing for a set period of time, so only when the power switch SW is completely turned off. It will trigger the action of switching the state of the switch, which can effectively avoid the interference caused by the ignition or leakage of the power switch SW. Since the addition overflow signal also has an action of lowering the reference, even if the OUTx voltage is maintained at a low level when the input voltage is low rather than completely powered down, the addition overflow signal will not continue, but will continue to trigger until the loop The circuit enters a balanced state, and there is no continuous timing signal to avoid false triggering of switch state switching.
当OUTx电压过高时，加减法计数器会一直进行减法，减小电解电容Co充电电流降低放电电压，从而降低OUTx电压。加减法计数器出现减法溢出时，减法溢出信号会加大参考电压来增加LEDx输出电流并维持计数器的正常工作，直至参考电压恢复至正常值。When the OUTx voltage is too high, the addition and subtraction counter will always perform subtraction, reducing the charging current of the electrolytic capacitor Co and reducing the discharge voltage, thereby reducing the OUTx voltage. When the subtraction overflow occurs in the addition and subtraction counter, the subtraction overflow signal will increase the reference voltage to increase the LEDx output current and maintain the normal operation of the counter until the reference voltage returns to the normal value.
实施例二 Embodiment 2
本实施例中提供一种线性LED驱动电路的电源开关检测方法，该电源开关检测方法可基于实施例一中的线性LED驱动电路实现，也可基于其它任意可检测电源开关导通状态的线性LED驱动电路实现。This embodiment provides a power switch detection method for a linear LED drive circuit. The power switch detection method can be implemented based on the linear LED drive circuit in the first embodiment, or can be based on any other linear LED that can detect the conduction state of the power switch. The drive circuit is implemented.
具体的，所述线性LED驱动电路的电源开关检测方法包括：对加减法计数器的加法溢出信号的持续时间进行计时，当加减法计数器的加法溢出信号的持续时间超过预设值时，判定电源开关SW关断。Specifically, the power switch detection method of the linear LED drive circuit includes: timing the duration of the addition overflow signal of the addition and subtraction counter, and when the duration of the addition overflow signal of the addition and subtraction counter exceeds a preset value, determine The power switch SW is turned off.
作为示例，检测所述线性LED驱动电路中LED灯段的负极电压，当所述LED灯段的负极电压高于预设值时，所述加减法计数器进行减法运算；当所述LED灯段的负极电压低于预设值时，所述加减法计数器进行加法运算。As an example, the negative electrode voltage of the LED lamp segment in the linear LED driving circuit is detected, and when the negative electrode voltage of the LED lamp segment is higher than a preset value, the addition and subtraction counter performs a subtraction operation; When the negative electrode voltage of 1 is lower than the preset value, the addition and subtraction counter performs addition operation.
作为示例，当所述加减法计数器进行减法运算时，降低所述线性LED驱动电路中电解电容的充电电流；当所述加减法计数器进行加法运算时，增加所述电解电容的充电电流。As an example, when the addition and subtraction counter performs a subtraction operation, the charging current of the electrolytic capacitor in the linear LED driving circuit is reduced; when the addition and subtraction counter performs an addition operation, the charging current of the electrolytic capacitor is increased.
作为示例，当所述加减法计数器产生加法计数溢出时，减小所述线性LED驱动电路中参考电压产生单元提供的参考电压；当所述加减法计数器产生减法计数溢出时，提高所述线性LED驱动电路中参考电压产生单元提供的参考电压。As an example, when the addition and subtraction counter overflows, the reference voltage provided by the reference voltage generating unit in the linear LED driving circuit is reduced; when the addition and subtraction counter overflows, the reference voltage is increased. The reference voltage provided by the reference voltage generation unit in the linear LED driving circuit.
实施例三Embodiment 3
本实施例中提供一种线性LED驱动电路的调光控制方法，可基于实施例二中所述的线性LED驱动电路的电源开关检测方法检测电源开关SW的状态，当检测到电源开关SW关断时，产生开关状态切换信号，并记忆当前工作状态。This embodiment provides a dimming control method for a linear LED drive circuit, which can detect the state of the power switch SW based on the power switch detection method for the linear LED drive circuit described in the second embodiment, and when it is detected that the power switch SW is turned off When the switch state switching signal is generated, and the current working state is memorized.
作为示例，当所述线性LED驱动电路中电解电容完全放电之前，若所述电源开关SW打开，电源接通后所述线性LED驱动电路中LED灯段切换进入下个工作状态；当所述电解电容完全放电后，对内部工作状态清零，再次上电时所述LED灯段进入默认工作状态。As an example, before the electrolytic capacitor in the linear LED driving circuit is completely discharged, if the power switch SW is turned on, the LED lamp segment in the linear LED driving circuit switches to the next working state after the power is turned on; After the capacitor is completely discharged, the internal working state is cleared, and the LED light segment enters the default working state when the power is turned on again.
作为示例，根据相应工作状态输出对应的参考电压以实现调光操作。As an example, the corresponding reference voltage is output according to the corresponding working state to realize the dimming operation.
请参阅图5，显示为通过环路加减法计数器溢出信号来做电源开关检测及切换控制的一种工作流程图，包括以下步骤：Please refer to Fig. 5, which shows a working flow chart of power switch detection and switching control through loop addition and subtraction counter overflow signal, including the following steps:
(1)开始检测电源开关导通状态；(1) Start to detect the conduction state of the power switch;
(2)加减法计数器工作；(2) The addition and subtraction counters work;
(3)判断加减法计数器状态是否加法溢出；(3) Judging whether the addition and subtraction counter status is addition overflow;
(4)若是，降低基准，若否，则返回上述步骤(2)；(4) If yes, lower the benchmark, if not, then return to above-mentioned step (2);
(5)判断溢出计时是否大于设定值；(5) Judge whether the overflow timing is greater than the set value;
(6)若是，则判断电源开关关断，进入下一状态，若否，则返回上述步骤(2)。(6) If yes, judge that the power switch is turned off and enter the next state; if not, return to the above step (2).
上述实施例仅例示性说明本发明的原理及其功效，而非用于限制本发明。任何熟悉此技术的人士皆可在不违背本发明的精神及范畴下，对上述实施例进行修饰或改变。因此，举凡所属技术领域中具有通常知识者在未脱离本发明所揭示的精神与技术思想下所完成的一切等效修饰或改变，仍应由本发明的权利要求所涵盖。The above-mentioned embodiments merely illustrate the principles and effects of the present invention, but are not intended to limit the present invention. Anyone skilled in the art can modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the technical field without departing from the spirit and technical idea disclosed in the present invention should still be covered by the claims of the present invention.

Claims (15)

  1. 一种线性LED驱动电路，其特征在于，包括：A linear LED drive circuit, characterized in that it includes:
    电源输入模块，输入端串联一电源开关，用于提供直流母线电压；Power input module, the input terminal is connected in series with a power switch to provide DC bus voltage;
    供电模块，连接所述电源输入模块的输出端，用于提供工作电压；a power supply module, connected to the output end of the power supply input module, and used for providing a working voltage;
    至少一驱动模块，连接于所述电源输入模块的输出端，用于驱动LED发光；at least one driving module, connected to the output end of the power input module, for driving the LED to emit light;
    电源开关检测模块，连接所述驱动模块并包括加减法计数器，基于所述加减法计数器的加法溢出信号的持续时间判断所述电源开关的导通或关断情况以进行调光控制。The power switch detection module is connected to the driving module and includes an addition and subtraction counter, and judges the on or off condition of the power switch based on the duration of the addition overflow signal of the addition and subtraction counter to perform dimming control.
  2. 根据权利要求1所述的线性LED驱动电路，其特征在于，所述驱动模块包括至少一驱动子模块，所述驱动子模块包括LED灯段、第一功率开关管、第一采样单元、参考电压产生单元及第一驱动单元，其中：The linear LED driving circuit according to claim 1, wherein the driving module comprises at least one driving sub-module, and the driving sub-module comprises an LED lamp segment, a first power switch tube, a first sampling unit, and a reference voltage A generating unit and a first driving unit, wherein:
    所述LED灯段的正极连接所述电源输入模块的输出端，负极连接所述第一功率开关管的漏极，所述第一功率开关管的源极经由所述第一采样单元接地；The positive pole of the LED lamp segment is connected to the output end of the power input module, the negative pole is connected to the drain of the first power switch tube, and the source of the first power switch tube is grounded via the first sampling unit;
    所述参考电压产生单元的输入端连接所述电源开关检测模块，输出端连接所述第一驱动单元的第一输入端；The input end of the reference voltage generating unit is connected to the power switch detection module, and the output end is connected to the first input end of the first driving unit;
    所述第一驱动单元的第二输入端连接所述第一功率开关管的源极，输出端连接所述第一功率开关管的栅极。The second input end of the first driving unit is connected to the source of the first power switch tube, and the output end is connected to the gate of the first power switch tube.
  3. 根据权利要求2所述的线性LED驱动电路，其特征在于：所述驱动模块包括多个所述驱动子模块，至少两个所述驱动子模块共用一所述参考电压产生单元。The linear LED driving circuit according to claim 2, wherein the driving module includes a plurality of the driving sub-modules, and at least two of the driving sub-modules share the reference voltage generating unit.
  4. 根据权利要求2所述的线性LED驱动电路，其特征在于：所述电源开关检测模块还包括参数检测模块、计时模块及模式选择模块，其中：The linear LED driving circuit according to claim 2, wherein the power switch detection module further comprises a parameter detection module, a timing module and a mode selection module, wherein:
    所述参数检测模块连接所述驱动模块及所述加减法计数器，用于检测所述驱动模块的预设参数并控制所述加减法计数器进行加法或减法运算；The parameter detection module is connected to the drive module and the addition/subtraction counter, and is used for detecting preset parameters of the drive module and controlling the addition/subtraction counter to perform addition or subtraction operations;
    所述计时模块连接所述加减法计数器的计数溢出端以对所述加减法计数器的加法溢出信号的持续时间进行计时；The timing module is connected to the counting overflow terminal of the addition and subtraction counter to time the duration of the addition overflow signal of the addition and subtraction counter;
    所述模式选择模块连接所述计时模块及所述参考电压产生单元，用于当加法溢出信号持续计时超过预设值时产生开关状态切换信号。The mode selection module is connected to the timing module and the reference voltage generating unit, and is used for generating a switch state switching signal when the addition overflow signal continues to clock over a preset value.
  5. 根据权利要求4所述的线性LED驱动电路，其特征在于：所述加减法计数器的计数溢出端还连接所述参考电压产生单元以根据溢出信号控制所述参考电压产生单元调整参 考电压的值。The linear LED driving circuit according to claim 4, wherein the counting overflow terminal of the addition and subtraction counter is further connected to the reference voltage generating unit to control the reference voltage generating unit to adjust the value of the reference voltage according to the overflow signal .
  6. 根据权利要求4所述的线性LED驱动电路，其特征在于：所述参数检测模块包括电压检测模块，所述电压检测模块连接所述LED灯段的负极及所述加减法计数器，以基于所述LED灯段的负极电压控制所述加减法计数器进行加法或减法运算。The linear LED driving circuit according to claim 4, wherein the parameter detection module comprises a voltage detection module, and the voltage detection module is connected to the negative electrode of the LED lamp segment and the addition and subtraction counter, so as to be based on the The negative voltage of the LED lamp segment controls the addition and subtraction counter to perform addition or subtraction operations.
  7. 根据权利要求4所述的线性LED驱动电路，其特征在于：所述参数检测模块包括源极电流检测模块，所述源极电流检测模块连接所述第一功率开关管的源极及所述加减法计数器，以基于所述第一功率开关管的源极电流控制所述加减法计数器进行加法或减法运算。The linear LED driving circuit according to claim 4, wherein the parameter detection module comprises a source current detection module, and the source current detection module is connected to the source of the first power switch tube and the voltage regulator. A subtraction counter is used to control the addition and subtraction counter to perform addition or subtraction based on the source current of the first power switch.
  8. 根据权利要求2所述的线性LED驱动电路，其特征在于，所述线性LED驱动电路还包括电解电容及充电电流控制模块，其中：The linear LED driving circuit according to claim 2, wherein the linear LED driving circuit further comprises an electrolytic capacitor and a charging current control module, wherein:
    所述电解电容的上极板连接所述LED灯段的正极，用于在所述母线电压小于所述电解电容上的电压时向所述LED灯段放电；The upper plate of the electrolytic capacitor is connected to the positive electrode of the LED lamp segment, and is used for discharging to the LED lamp segment when the busbar voltage is lower than the voltage on the electrolytic capacitor;
    所述充电电流控制模块连接所述加减法计数器、所述电源输入模块的输出端及所述电解电容的下极板，基于所述加减法计数器的控制信号及所述电源输入模块的输出电压调整所述电解电容的充放电电流。The charging current control module is connected to the addition and subtraction counter, the output end of the power input module and the lower plate of the electrolytic capacitor, based on the control signal of the addition and subtraction counter and the output of the power input module The voltage adjusts the charging and discharging current of the electrolytic capacitor.
  9. 根据权利要求8所述的线性LED驱动电路，其特征在于：所述充电电流控制模块包括母线电压检测模块、补偿电压产生电路、数模转换单元、第二驱动单元、第二功率开关管、第二采样单元及第三采样单元，其中：The linear LED driving circuit according to claim 8, wherein the charging current control module comprises a bus voltage detection module, a compensation voltage generating circuit, a digital-to-analog conversion unit, a second driving unit, a second power switch, a first The second sampling unit and the third sampling unit, wherein:
    所述母线电压检测模块连接所述电源输入模块的输出端以对所述母线电压进行检测；The busbar voltage detection module is connected to the output end of the power input module to detect the busbar voltage;
    所述第二驱动单元的第一输入端连接所述补偿电压产生电路，所述第二驱动单元的第二输入端连接所述母线电压检测模块的输出端，所述第二驱动单元的输出端连接所述第二功率开关管的栅极；The first input end of the second drive unit is connected to the compensation voltage generating circuit, the second input end of the second drive unit is connected to the output end of the bus voltage detection module, and the output end of the second drive unit connecting the grid of the second power switch tube;
    所述数模转换单元连接于所述补偿电压产生电路与所述加减法计数器之间；The digital-to-analog conversion unit is connected between the compensation voltage generating circuit and the addition and subtraction counter;
    所述第二功率开关管的漏极连接所述电解电容的下极板，源极经由所述第二采样单元与所述第二驱动单元的第二输入端连接，并经由所述第三采样单元接地。The drain of the second power switch tube is connected to the lower plate of the electrolytic capacitor, the source is connected to the second input end of the second driving unit via the second sampling unit, and is connected to the second input end of the second driving unit via the third sampling unit Unit is grounded.
  10. 一种线性LED驱动电路的电源开关检测方法，其特征在于，包括：对加减法计数器 的加法溢出信号的持续时间进行计时，当所述加减法计数器的所述加法溢出信号的持续时间超过预设值时，判定所述电源开关关断。A method for detecting a power switch of a linear LED drive circuit, comprising: timing the duration of an addition overflow signal of an addition and subtraction counter, and when the duration of the addition overflow signal of the addition and subtraction counter exceeds When the preset value is set, it is determined that the power switch is turned off.
  11. 根据权利要求10所述的线性LED驱动电路的电源开关检测方法，其特征在于：检测所述线性LED驱动电路中LED灯段的负极电压，当所述LED灯段的负极电压高于预设值时，所述加减法计数器进行减法运算；当所述LED灯段的负极电压低于预设值时，所述加减法计数器进行加法运算。The method for detecting a power switch of a linear LED driving circuit according to claim 10, wherein the negative voltage of the LED lamp segment in the linear LED driving circuit is detected, and when the negative voltage of the LED lamp segment is higher than a preset value When , the addition and subtraction counter performs a subtraction operation; when the negative electrode voltage of the LED lamp segment is lower than a preset value, the addition and subtraction counter performs an addition operation.
  12. 根据权利要求11所述的线性LED驱动电路的电源开关检测方法，其特征在于：当所述加减法计数器进行减法运算时，降低所述线性LED驱动电路中电解电容的充电电流；当所述加减法计数器进行加法运算时，增加所述电解电容的充电电流。The method for detecting a power switch of a linear LED driving circuit according to claim 11, wherein: when the addition and subtraction counter performs a subtraction operation, the charging current of the electrolytic capacitor in the linear LED driving circuit is reduced; When the addition and subtraction counter performs addition operation, the charging current of the electrolytic capacitor is increased.
  13. 根据权利要求11所述的线性LED驱动电路的电源开关检测方法，其特征在于：当所述加减法计数器产生加法计数溢出时，减小所述线性LED驱动电路中参考电压产生单元提供的参考电压；当所述加减法计数器产生减法计数溢出时，提高所述线性LED驱动电路中所述参考电压产生单元提供的参考电压。The method for detecting a power switch of a linear LED driving circuit according to claim 11, wherein when the addition and subtraction counter overflows in an addition count, the reference voltage provided by the reference voltage generating unit in the linear LED driving circuit is reduced. voltage; when the addition and subtraction counter overflows when the subtraction count is generated, the reference voltage provided by the reference voltage generation unit in the linear LED driving circuit is increased.
  14. 一种线性LED驱动电路的调光控制方法，其特征在于：采用如权利要求10所述的线性LED驱动电路的电源开关检测方法检测所述电源开关的状态，当检测到所述电源开关关断时，产生开关状态切换信号，并记忆当前工作状态。A dimming control method for a linear LED drive circuit, characterized in that: the power switch detection method for a linear LED drive circuit according to claim 10 is used to detect the state of the power switch, and when it is detected that the power switch is turned off When the switch state switching signal is generated, and the current working state is memorized.
  15. 根据权利要求14所述的线性LED驱动电路的调光控制方法，其特征在于：当所述线性LED驱动电路中电解电容完全放电之前，若所述电源开关打开，电源接通后所述线性LED驱动电路中LED灯段切换进入下个工作状态；当所述电解电容完全放电后，对内部工作状态清零，再次上电时所述LED灯段进入默认工作状态。The dimming control method for a linear LED driving circuit according to claim 14, wherein: before the electrolytic capacitor in the linear LED driving circuit is completely discharged, if the power switch is turned on, the linear LED is turned on after the power is turned on. The LED lamp segment in the drive circuit switches to enter the next working state; when the electrolytic capacitor is completely discharged, the internal working state is cleared, and the LED lamp segment enters the default working state when powered on again.
PCT/CN2021/138248 2021-04-01 2021-12-15 Linear led driving circuit, power switch detection method, and dimming control method WO2022206030A1 (en)

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