[go: up one dir, main page]

CN114679812B - LED driving circuit, driving method thereof and electronic equipment - Google Patents

LED driving circuit, driving method thereof and electronic equipment

Info

Publication number
CN114679812B
CN114679812B CN202210200177.0A CN202210200177A CN114679812B CN 114679812 B CN114679812 B CN 114679812B CN 202210200177 A CN202210200177 A CN 202210200177A CN 114679812 B CN114679812 B CN 114679812B
Authority
CN
China
Prior art keywords
driving
terminal
output
voltage
led
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN202210200177.0A
Other languages
Chinese (zh)
Other versions
CN114679812A (en
Inventor
李育军
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Beijing Eswin Computing Technology Co Ltd
Original Assignee
Beijing Eswin Computing Technology Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Beijing Eswin Computing Technology Co Ltd filed Critical Beijing Eswin Computing Technology Co Ltd
Priority to CN202210200177.0A priority Critical patent/CN114679812B/en
Publication of CN114679812A publication Critical patent/CN114679812A/en
Application granted granted Critical
Publication of CN114679812B publication Critical patent/CN114679812B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • 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
    • 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
    • H05B45/32—Pulse-control circuits
    • H05B45/325—Pulse-width modulation [PWM]
    • 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
    • H05B45/37—Converter 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]
    • H05B45/30—Driver circuits
    • H05B45/37—Converter circuits
    • H05B45/3725—Switched mode power supply [SMPS]

Landscapes

  • Control Of Indicators Other Than Cathode Ray Tubes (AREA)
  • Circuit Arrangement For Electric Light Sources In General (AREA)

Abstract

本申请实施例提供了一种LED驱动电路及其驱动方法、电子设备。该LED驱动电路包括：多路LED灯串、电源转换电路、亮度控制模块和电流源；每一路LED灯串均包括第一端和第二端；亮度控制模块用于输出亮度数据给电源转换电路和电流源；电源转换电路用于根据亮度数据输出参考电压，并实时接收第二端的电压，若多个第二端的电压中最小电压与参考电压相等，提供稳定的工作电压给各个第一端；否则，用于形成一反馈回路，反馈回路用于使得最小电压与参考电压相等；电流源包括若干单路电流源，一路单路电流源与一路LED灯串的第二端一一对应连接，每一路单路电流源用于根据亮度数据，输出不同大小的驱动电流。本申请实施例能够降低LED驱动电路的功耗。

The embodiments of the present application provide an LED driving circuit, a driving method thereof, and an electronic device. The LED driving circuit includes: multiple LED light strings, a power conversion circuit, a brightness control module, and a current source; each LED light string includes a first end and a second end; the brightness control module is used to output brightness data to the power conversion circuit and the current source; the power conversion circuit is used to output a reference voltage based on the brightness data and receive the voltage of the second end in real time. If the minimum voltage among the multiple second end voltages is equal to the reference voltage, a stable operating voltage is provided to each first end; otherwise, a feedback loop is used to form a feedback loop for making the minimum voltage equal to the reference voltage; the current source includes a plurality of single current sources, each single current source is connected to the second end of an LED light string in a one-to-one correspondence, and each single current source is used to output a driving current of different sizes based on the brightness data. The embodiments of the present application can reduce the power consumption of the LED driving circuit.

Description

LED driving circuit, driving method thereof and electronic equipment
Technical Field
The application relates to the technical field of integrated circuits, in particular to an LED driving circuit, a driving method thereof and electronic equipment.
Background
Conventional LED (LIGHT EMITTING Diode) driving circuits generally use basic current control circuits as main components, and part of the driving circuits may integrate a power conversion (DC-DC) circuit for supplying power to the LED strings. The current of the LED driving circuit needs to be adjustable, whether it is a separate current control circuit or an LED driving circuit integrated with a power conversion circuit, and this adjustment usually consists of a maximum current adjustment and a brightness adjustment, and there are various ways of brightness adjustment, in which PWM (Pulse Width Modulation ) dimming is commonly used, that is, the switching of the LED is controlled by a PWM square wave signal, for example, the LED is turned on when the PWM square wave signal is at a high level, and the LED is turned off when the PWM square wave signal is at a low level, so as to realize that the brightness of the lamp changes along with the change of the duty ratio of the PWM signal.
The dimming contrast ratio refers to the ratio of the period of the PWM square wave signal to the high level time of the PWM square wave signal, and under the requirement of higher and higher dimming contrast ratio, a large driving stage is required for realizing dimming with a smaller duty ratio, which requires a larger driving current, and in a battery powered system such as a notebook computer and a tablet personal computer, it is very important to reduce the power consumption of the whole system and improve the power supply efficiency.
Disclosure of Invention
The application provides an LED driving circuit, a driving method thereof and electronic equipment, which are used for solving the technical problem that the power consumption is high when the dimming contrast ratio is high in the driving circuit design in the prior art.
In a first aspect, an embodiment of the present application provides an LED driving circuit, including a plurality of LED strings, a power conversion circuit, a brightness control module, and a current source;
Each path of LED lamp string comprises a first end and a second end;
the brightness control module is used for outputting brightness data to the power supply conversion circuit and the current source;
The power supply conversion circuit is used for outputting reference voltage according to the brightness data, receiving the voltage of the second end in real time, and providing stable working voltage for each first end if the minimum voltage in the voltages of the second ends is equal to the reference voltage;
The current sources comprise a plurality of single-path current sources, one path of the single-path current sources is connected with the second ends of one path of the LED lamp strings in a one-to-one correspondence mode, and each path of the single-path current sources is used for outputting driving currents with different magnitudes according to the brightness data.
Optionally, the power conversion circuit comprises a feedback receiving circuit and a power module;
the feedback receiving circuit is respectively connected with the brightness control module and the second end of each LED lamp string, and is used for receiving the voltage of the second end in real time, selecting a minimum voltage from the voltages of a plurality of second ends, outputting a reference voltage according to brightness data output by the brightness control module, comparing the minimum voltage with the reference voltage, and outputting a comparison result to the power supply module;
The power module is respectively connected with the voltage input end, the feedback receiving circuit and the first ends of each LED lamp string, and is used for providing stable working voltage for each first end when the comparison result is that the minimum voltage is equal to the reference voltage, and forming a feedback loop when the comparison result is that the minimum voltage is unequal to the reference voltage.
Optionally, the feedback receiving circuit comprises an output feedback network, a first digital-to-analog conversion circuit and an error amplifier;
the input end of the output feedback network is respectively connected with each second end, the output end of the output feedback network is connected with the inverting input end of the error amplifier, and the output end of the output feedback network is used for selecting a minimum voltage from the voltages of a plurality of second ends and inputting the minimum voltage into the inverting input end;
the input end of the first digital-to-analog conversion circuit is connected with the brightness control module, the output end of the first digital-to-analog conversion circuit is connected with the non-inverting input end of the error amplifier, and the first digital-to-analog conversion circuit is used for receiving the brightness data output by the brightness control module, converting the brightness data into corresponding brightness and outputting a reference voltage according to the brightness;
the output end of the error amplifier is connected with the power supply module and is used for receiving the reference voltage and the minimum voltage, comparing the minimum voltage with the reference voltage and outputting a comparison result to the power supply module.
Optionally, the power module comprises a switch tube, an inductor and a freewheeling diode;
the control end of the switching tube is connected with the output end of the error amplifier, the first pole is connected with the first end of the inductor, and the second pole is grounded;
the second end of the inductor is connected with the voltage input end;
The positive pole of the freewheel diode is connected with the first end of inductance, and the negative pole is connected with the first end.
Optionally, the current source includes a second digital-to-analog conversion circuit, and each single-path current source includes an operational amplifier and a multi-stage driving module;
the second digital-to-analog conversion circuit is respectively connected with the brightness control module, the non-inverting input end of each operational amplifier and the driving modules of other stages except the first-stage driving module in each single-circuit current source, and is used for receiving the brightness data output by the brightness control module, converting the brightness data into corresponding brightness and inputting the corresponding brightness into the non-inverting input end of the operational amplifier, controlling whether the driving module connected with the second digital-to-analog conversion circuit is conducted with the inverting input end of the operational amplifier or not according to the brightness data, and controlling whether the driving module connected with the second digital-to-analog conversion circuit is conducted with the output end of the operational amplifier or not;
The control end of a first-stage driving module in each single-path current source is connected with the output end of the operational amplifier, the first end of the first-stage driving module is connected with the second end of the LED lamp string, the second end of the first-stage driving module is connected with the inverting input end of the operational amplifier, and the third end of the first-stage driving module is grounded;
The control end of the rest stage driving modules in each single-path current source is connected with the output end of the operational amplifier through a first switch unit, the first end is connected with the second end of the LED lamp string, the second end is connected with the inverting input end of the operational amplifier through a second switch unit, and the third end is grounded, wherein:
The first and second switching units are configured to be turned on or off according to the luminance data.
Optionally, the first stage driving module in each one-way current source comprises a first driving transistor and a first resistor;
The control end of the first driving transistor is connected with the output end of the operational amplifier, the first pole is connected with the second end of the LED lamp string, and the second pole is connected with the inverting input end of the operational amplifier;
The first end of the first resistor is connected with the second pole of the first driving transistor, and the second end of the first resistor is grounded;
In the rest stage driving modules in each single-path current source, each stage driving module comprises a second driving transistor and a second resistor;
The control end of the second driving transistor is connected with the output end of the operational amplifier through the first switching unit, the first pole is connected with the second end of the LED lamp string, and the second pole is connected with the inverting input end of the operational amplifier through the second switching unit;
the first end of the second resistor is connected with the second pole of the second driving transistor, and the second end is grounded.
Optionally, the first stage driving module in each one-way current source further comprises a first high-voltage driving tube and a first driver;
the control end of the first high-voltage driving tube is connected with a power supply, the first pole is connected with the second end of the LED lamp string, and the second pole is connected with the first pole of the first driving transistor;
the first end of the first driver is connected with the output end of the operational amplifier, and the second end of the first driver is connected with the control end of the first driving transistor;
in the rest stage driving modules in each single-path current source, each stage driving module further comprises a second high-voltage driving tube and a second driver;
The control end of the second high-voltage driving tube is connected with a power supply, the first pole is connected with the second end of the LED lamp string, and the second pole is connected with the first pole of the second driving transistor;
The first end of the second driver is connected with the output end of the operational amplifier through the first switch unit, and the second end of the second driver is connected with the control end of the second driving transistor.
Optionally, each of the single-path current sources further includes a third switching unit;
the first end of the third switch unit is respectively connected with the control end of the first driving transistor and the control end of the second driving transistor, the second end of the third switch unit is grounded, and the control end of the third switch unit is connected with the output end of the pulse adjusting signal and used for being conducted or disconnected under the control of the pulse adjusting signal.
Optionally, the LED driving circuit further includes a filter capacitor, where a first end of the filter capacitor is connected to an output end of the power conversion circuit, and a second end of the filter capacitor is grounded and used for performing filtering processing on a voltage output by the power conversion circuit.
In a second aspect, an embodiment of the present application provides an electronic device, where the electronic device includes the LED driving circuit provided by the embodiment of the present application.
In a third aspect, an embodiment of the present application provides a driving method of the above LED driving circuit, including:
the power supply conversion circuit receives the brightness data output by the brightness control module and provides working voltage for each first end according to the brightness data;
And the current source receives the brightness data output by the brightness control module and outputs driving currents with different magnitudes to the LED lamp string according to the brightness data.
The technical scheme provided by the embodiment of the application at least has the following beneficial effects:
In the LED driving circuit provided by the embodiment of the application, when the minimum voltage in the voltages of the second ends is equal to the reference voltage, the power supply conversion circuit provides the working voltage for each first end, namely the LED lamp string, and the value of the reference voltage is output according to the brightness data, so that the power consumption of the power supply conversion circuit can be reduced and the power consumption of the LED driving circuit can be further reduced because the value of the reference voltage can be smaller when the brightness is lower.
Additional aspects and advantages of the application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the application.
Drawings
The foregoing and/or additional aspects and advantages of the application will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings, in which:
Fig. 1 is a schematic structural diagram of an LED driving circuit according to an embodiment of the present application;
fig. 2 is a schematic structural diagram of another LED driving circuit according to an embodiment of the present application;
fig. 3 is a schematic structural diagram of another LED driving circuit according to an embodiment of the present application;
Fig. 4 is a schematic structural diagram of a first digital-to-analog conversion circuit and a single-path current source according to an embodiment of the present application;
Fig. 5 is a schematic diagram of a first digital-to-analog conversion circuit and a single-channel current source according to an embodiment of the present application;
fig. 6 is a schematic diagram of a structure of a first digital-to-analog conversion circuit and a single-channel current source according to an embodiment of the present application;
fig. 7 is a schematic diagram of a structure of a first digital-to-analog conversion circuit and a single-channel current source according to an embodiment of the present application;
fig. 8 is a flowchart of a driving method of an LED driving circuit according to an embodiment of the present application.
Reference numerals illustrate:
the LED lamp comprises a 1-LED lamp string, a 2-power supply conversion circuit, a 3-brightness control module, a 4-current source and a 5-filter capacitor;
41-a single-path current source, 21-a feedback receiving circuit, 22-a power module, 211-an output feedback network, 212-a first digital-to-analog conversion circuit, 213-an error amplifier, 221-a switch tube, 222-an inductor and 223-a freewheeling diode;
411-second digital-to-analog conversion circuit, 412-operational amplifier, 413-driving module, 414-first switch unit, 415-second switch unit, 416-first high voltage driving tube, 417-first driver, 418-power supply, 419-second high voltage driving tube, 420-second driver, 421-third switch unit.
Detailed Description
The present application is described in detail below, examples of embodiments of the application are illustrated in the accompanying drawings, wherein the same or similar reference numerals refer to the same or similar components or components having the same or similar functions throughout. Further, if detailed description of the known technology is not necessary for the illustrated features of the present application, it will be omitted. The embodiments described below by referring to the drawings are illustrative only and are not to be construed as limiting the application.
It will be understood by those skilled in the art that all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs unless defined otherwise. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the prior art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
As used herein, the singular forms "a", "an", "the" and "the" are intended to include the plural forms as well, unless expressly stated otherwise, as understood by those skilled in the art. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. It will be understood that when an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. Further, "connected" as used herein may include wireless connections. The term "and/or" as used herein includes all or any element and all combination of one or more of the associated listed items.
In the related art, in order to reduce power consumption, an LED driving circuit of an integrated power conversion circuit may reduce power consumption by some low-power design methods, for example, reducing power consumption during light load and standby of a notebook computer, a tablet computer. The number of LED channels in these hardware systems increases with the increase of the screen size, and the current magnitude variation range is very large with the increase of the screen contrast, which puts higher demands on the LED driving efficiency. For LED driving, the driving capability of a corresponding driving circuit can be adjusted in real time according to the current or brightness, so that the system efficiency can be remarkably improved.
The application provides a novel LED driving circuit and a driving method thereof, which can improve the contrast ratio of PWM dimming driven by LEDs and reduce power consumption.
As shown in fig. 1, the embodiment of the application provides an LED driving circuit, which comprises multiple paths of LED strings 1 (a first path of LED string, a second path of LED string and an nth path of LED string in the N paths of LED strings 1 are shown in the figure), a power conversion circuit 2, a brightness control module 3 and a current source 4, wherein each path of LED string 1 comprises a first end (one end connected with VOUT in the figure) and a second end (one end corresponding to VLED1, VLED2 and VLEDN in the figure), the brightness control module 3 is used for outputting brightness data to the power conversion circuit 2 and the current source 4, the power conversion circuit 2 is used for outputting a reference voltage Vref according to the brightness data and receiving the voltage of the second end in real time, and providing a stable working voltage VOUT to each first end if the minimum voltage in the voltages of the second ends is equal to the reference voltage Vref, otherwise, the feedback circuit is used for forming a feedback loop so that the minimum voltage is equal to the reference voltage Vref, the current source 4 comprises a plurality of single current sources 41, and each single current source 41 is correspondingly connected with the second ends of the LED string 1, and each single current source 41 is used for driving different brightness data according to the brightness data.
In the embodiment of the application, when the minimum voltage in the voltages of the second ends is equal to the reference voltage Vref, the power conversion circuit 2 provides the working voltage VOUT for each first end, namely the LED lamp string 1, and because the value of the reference voltage Vref is output according to the brightness data, when the brightness is lower, the value of the reference voltage Vref can also be output smaller, so that the power consumption of the power conversion circuit 2 can be reduced, and the power consumption of the LED driving circuit can be further reduced.
In the embodiment of the present application, the luminance control module 3 is a digital part, that is, the luminance data output by the luminance control module 3 is a digital signal, and the power conversion circuit 2 and the current source 4 are analog parts, that is, the power conversion circuit 2 and the current source 4 need to process the analog signal. Thus, the power conversion circuit 2 and the current source 4 each include a digital-to-analog converter (DAC) to convert received luminance data into luminance values.
It should be noted that, because the performances of the LEDs are not completely the same, the voltage at the second end of each LED light string 1 is not completely the same, but the voltage at the first end of each LED light string 1 is the same, so that in order to ensure that each LED light string 1 can work normally, it is necessary to ensure that one LED light string 1 with the minimum voltage at the second end can work normally, so that in the embodiment of the present application, when the minimum voltage in the voltages at the second ends is equal to the reference voltage Vref, the power conversion circuit 2 provides the working voltage VOUT for each first end.
In a specific embodiment, as shown in fig. 2, the power conversion circuit 2 in the embodiment of the present application includes a feedback receiving circuit 21 and a power module 22, where the feedback receiving circuit 21 is respectively connected to the brightness control module 3 and the second end of each LED string 1, and is configured to receive the voltage of the second end of each LED string 1 in real time, select a minimum voltage among the voltages of the second ends, output a reference voltage Vref according to brightness data output by the brightness control module 3, and compare the minimum voltage of the voltages of the second ends with the reference voltage Vref, and output the comparison result to the power module 22, and the power module 22 is respectively connected to the voltage input end (the port of the input voltage VIN in the figure), the feedback receiving circuit 21, and the first end of each LED string 1, and is configured to provide a stable operating voltage to each first end when the comparison result is that the minimum voltage is equal to the reference voltage Vref, and form a feedback loop when the comparison result is that the minimum voltage is unequal to the reference voltage Vref.
Specifically, as shown in fig. 2, in the embodiment of the present application, the feedback receiving circuit 21 includes an output feedback network 211, a first digital-to-analog conversion circuit 212 and an error amplifier 213, wherein an input end of the output feedback network 211 is respectively connected to the second ends of the LED strings 1, an output end of the output feedback network 211 is connected to an inverting input end of the error amplifier 213, and is used for selecting a minimum voltage from the voltages of the second ends of the LED strings 1, inputting the minimum voltage to the inverting input end of the error amplifier 213, an input end of the first digital-to-analog conversion circuit 212 is connected to the luminance control module 3, an output end of the first digital-to-analog conversion circuit 212 is connected to an non-inverting input end of the error amplifier 213, and is used for receiving luminance data outputted from the luminance control module 3, converting luminance data into corresponding luminance, and outputting a reference voltage Vref according to luminance, an output end of the error amplifier 213 is connected to the power module 22, and is used for receiving the reference voltage Vref and the voltage outputted from the output feedback network 211 (i.e. receiving the minimum voltage from the voltages of the second ends of the LED strings 1), and comparing the minimum voltage with the reference voltage Vref, and outputting the comparison result to the power module 22.
In the embodiment of the present application, the power module 22 may be a voltage boosting circuit or a voltage dropping circuit, and the embodiment of the present application does not limit the type of the power module 22. In one embodiment, as shown in fig. 2, the power module 22 includes a switching tube 221, an inductor 222 and a freewheeling diode 223, where a control terminal of the switching tube 22 is connected to an output terminal of the error amplifier 213, a first terminal of the switching tube is connected to a first terminal of the inductor 222, a second terminal of the switching tube is grounded, a second terminal of the switching tube 222 is connected to a voltage input terminal (a port of the input voltage VIN in the drawing), and an anode of the freewheeling diode 223 is connected to the first terminal of the switching tube and a cathode of the freewheeling diode 223 is connected to the first terminal.
It should be noted that, as shown in fig. 2, the control end of the switch tube 22 and the output end of the error amplifier 213 may not be directly connected, but a logic control circuit is disposed between the control end of the switch tube 22 and the output end of the error amplifier 213, and the switch tube 22 is controlled by the logic control circuit, so that a specific implementation manner of the logic control circuit is similar to that of the prior art, and since the part does not relate to the application point of the present application, the description is omitted here.
It should be noted that, in the embodiment of the present application, the switching transistor 221 may be a transistor, specifically, a thin film transistor, or a Metal-Oxide-semiconductor field effect transistor (MOSFET), the first electrode of the transistor may be a source electrode, the second electrode may be a drain electrode, the first electrode may be a drain electrode, and the second electrode may be a source electrode, and the transistor may be an N-type transistor, or a P-type transistor.
It should be noted that, the specific method for selecting a minimum voltage in the voltages of the second ends of the LED strings 1 by the output feedback network 211 is similar to the prior art, and will not be repeated here. In addition, the specific manner in which the first digital-to-analog conversion circuit 212 outputs the reference voltage Vref according to the brightness in the embodiment of the present application will be described below, which is not described here.
Further, as shown in fig. 3, the LED driving circuit in the embodiment of the present application further includes a filter capacitor 5, where a first end of the filter capacitor 5 is connected to an output end of the power conversion circuit 2, and a second end of the filter capacitor is grounded and is used for performing filtering processing on a voltage output by the power conversion circuit 2, and the setting of the filter capacitor 5 can remove noise interference, so that the voltage input to the first end of the LED string 1 is more stable, and the filter capacitor 5 can specifically select a filter capacitor commonly used in the prior art, which is not described herein again.
It should be noted that, as shown in fig. 3, since the current source 4 is an analog part and the luminance control module 3 is a digital part, the current source 4 also includes a digital-to-analog converter (DAC), and specifically, in order to save circuit wiring and reduce circuit power consumption, each of the single-path current sources 41 shares one digital-to-analog converter. Switches S1, S2 and SN in fig. 3 are all controlled by PWM square wave signals, and at high levels of the PWM square wave signals, switches S1, S2 and SN are closed, and at low levels of the PWM square wave signals, switches S1, S2 and SN are open. In addition, the DRV in fig. 3 includes an operational amplifier and other devices, and the arrangement of the single-path current sources 41 in the embodiment of the present application is the same, and the specific arrangement of one single-path current source 41 will be described in detail below.
In a specific embodiment, as shown in fig. 4, the current source 4 in the embodiment of the present application includes a second digital-to-analog conversion circuit 411, each single-channel current source 41 (only one single-channel current source 41 is shown in the figure) includes an operational amplifier 412 and a multi-stage driving module 413, the second digital-to-analog conversion circuit 411 is respectively connected to the brightness control module 3, the non-inverting input terminal of each operational amplifier 412, and the remaining driving modules 413 except the first driving module 413 (the driving module 413 directly connected to the output terminal of the operational amplifier 412) in each single-channel current source 41, and is configured to receive the brightness data outputted by the brightness control module 3, convert the brightness data into the non-inverting input terminal of the corresponding brightness input operational amplifier 412, and control, according to the brightness data, whether the driving module 413 connected to the second digital-to-analog conversion circuit 411 is in conduction with the inverting input terminal of the operational amplifier 412, and control whether the driving module 413 connected to the second digital-to-analog conversion circuit 411 is in conduction with the output terminal of the operational amplifier 412.
Specifically, as shown in fig. 4, a control end of a first stage driving module 413 in each single-path current source 41 is connected to an output end of an operational amplifier 412, a first end is connected to a second end of the LED string 1, a second end is connected to an inverting input end of the operational amplifier 412, and a third end is grounded, a control end of the remaining stage driving modules 413 in each single-path current source 41 is connected to an output end of the operational amplifier 412 through a first switching unit 414, a first end is connected to the second end of the LED string 1, a second end is connected to an inverting input end of the operational amplifier 412 through a second switching unit 415, and a third end is grounded, wherein the first switching unit 414 and the second switching unit 415 are configured to be turned on or off according to luminance data.
It should be noted that, the voltage difference between the second end and the third end of the first stage driving module 413, that is, the voltage difference between the second end and the third end is different, and the two are not the same, and the implementation manner of the voltage difference between the second end and the third end will be described below, where, among the wires connected to the first stage driving module 413 and the ground point, the position where the wires connected to the inverting input end of the operational amplifier 412 intersect may be the second end of the first stage driving module 413, and the end connected to the ground point may be the third end of the first stage driving module 413, and similarly, the second ends and the third ends of the remaining stage driving modules 413 are arranged in the same manner as the first stage driving module 413.
In particular, the first switch unit 414 and the second switch unit 415 in the embodiment of the present application may be transistors or logic gates, and the embodiment of the present application does not limit the specific types of the first switch unit 414 and the second switch unit 415, and when the first switch unit 414 and the second switch unit 415 are transistors, the first switch unit 414 and the second switch unit 415 may select the same transistor in order to save production cost.
In particular, when the value of the luminance data is high, the first switch unit 414 and the second switch unit 415 in the embodiment of the application are all turned on, and when the value of the luminance data is low, under the control of the luminance data, part of the first switch unit 414 and the second switch unit 415 are turned off, for example, when the luminance data is 1111, the luminance is highest, and when the luminance data is 0001, all of the first switch unit 414 and the second switch unit 415 are turned on, and when the luminance data is 0001, the luminance is low, and only the first stage driving module 413 is in an operating state, and when the luminance data is 0011 or 0101, the luminance is between the highest luminance and the lowest luminance, and at this time, part of the first switch unit 414 and the second switch unit 415 can be turned off through the control of the luminance data, and part of the first switch unit 414 and the second switch unit 415 can be turned on, and the power consumption of the LED driving circuit can be reduced.
In an alternative embodiment, as shown in fig. 5, in the embodiment of the present application, the first stage driving module 413 in each single-path current source 41 includes a first driving transistor T1 and a first resistor R1, the control end of the first driving transistor T1 is connected to the output end of the operational amplifier 412, the first pole is connected to the second end of the LED string 1, the second pole is connected to the inverting input end of the operational amplifier 412, the first end of the first resistor R1 is connected to the second pole of the first driving transistor T1, the second end is grounded, the remaining stage driving modules 413 in each single-path current source 41 include a second driving transistor T2 and a second resistor R2, the control end of the second driving transistor T2 is connected to the output end of the operational amplifier 412 through the first switching unit 414, the first pole is connected to the second end of the LED string 1, the second pole is connected to the inverting input end of the operational amplifier 412 through the second switching unit 415, and the first end of the second resistor R2 is connected to the second end of the second driving transistor T2.
It should be noted that, in the embodiment of the present application, the first driving transistor T1 and the second driving transistor T2 are the same driving transistor, and the first pole and the second pole of the first driving transistor T1 may be interchanged, specifically, in one embodiment, the first pole and the second pole of the first driving transistor T1 may be the source electrode, the second pole may be the drain electrode, and in another embodiment, the first pole and the second pole of the first driving transistor T1 may be the drain electrode, the second pole may be the source electrode, and similarly, the first pole and the second pole of the second driving transistor T2 may be interchanged.
It should be noted that, in the embodiment of the present application, the first resistor R1 and the second resistor R2 may be selected to have the same resistance, specifically, the resistance values of the first resistor R1 and the second resistor R2 are equal, and the specific setting manner of the first resistor R1 and the second resistor R2 is set according to actual needs, which is not limited herein.
In another alternative embodiment, as shown in fig. 6, the first stage driving module 413 in each single-path current source 41 further includes a first high-voltage driving tube 416 and a first driver 417, the control end of the first high-voltage driving tube 416 is connected to the power supply 418, the first pole is connected to the second end of the LED string 1, the second pole is connected to the first pole of the first driving transistor T1, the first end of the first driver 417 is connected to the output end of the operational amplifier 412, the second end is connected to the control end of the first driving transistor T1, in the remaining stage driving modules 413 in each single-path current source 41, each stage driving module 413 further includes a second high-voltage driving tube 419 and a second driver 420, the control end of the second high-voltage driving tube 419 is connected to the power supply 418, the first pole is connected to the second end of the LED string 1, the second pole is connected to the first pole of the second driving transistor T2, and the first end of the second driver 420 is connected to the output end of the operational amplifier 412 through the first switch unit 414.
It should be noted that, in the embodiment of the present application, the voltage output by the power supply 418 is a high level voltage, and the specific voltage value is set according to the actual requirement.
It should be noted that, in the embodiment of the present application, the first high-voltage driving transistor 416 and the second high-voltage driving transistor 419 are the same high-voltage driving transistor, the first pole and the second pole of the first high-voltage driving transistor 416 may be interchanged, the first pole and the second pole of the second high-voltage driving transistor 419 may also be interchanged, and the first high-voltage driving transistor 416 and the second high-voltage driving transistor 419 are used to buffer the voltage output from the second end of the LED light string 1 to the first driving transistor T1 and the second driving transistor T2, so that the voltage received by the first driving transistor T1 and the second driving transistor T2 is smaller than the highest withstand voltage thereof.
It should be noted that, in the embodiment of the present application, the first driver 417 and the second driver 420 may be the same driver, and the first driver 417 and the second driver 420 have no gain, which may play a role in driving enhancement.
Further, as shown in fig. 7, each one-way current source 41 in the embodiment of the present application further includes a third switch unit 421, wherein a first end of the third switch unit 421 is connected to a control end of the first driving transistor T1 and a control end of the second driving transistor T2, respectively, and a second end of the third switch unit is grounded, and the control end of the third switch unit is connected to an output end of a pulse adjustment signal (PWM) for being turned on or off under the control of the pulse adjustment signal (PWM). Specifically, the third switch unit 421 in the embodiment of the present application may be a transistor, and the embodiment of the present application does not limit the specific type of the third switch unit 421, and when the PWM square wave signal is high, the third switch unit 421 is turned off, and when the PWM square wave signal is low, the third switch unit 421 is turned on.
As shown in fig. 3 and 7, in the embodiment of the present application, the reference voltage Vref is generated by the first digital-to-analog conversion circuit 212, and finally, the minimum voltage at the second end of the LED string light 1 is equal to the reference voltage Vref through the feedback loop.
Specifically, as shown in fig. 7, the first digital-to-analog conversion circuit 212 in fig. 7 provides a way of adjusting the reference voltage Vref by means of current adjustment, and the reference voltage Vref can be adjusted by adjusting the value of the resistor in the first digital-to-analog conversion circuit 212.
As shown in fig. 3 and 7, the first and second driving transistors T1 and T2 generally require relatively large power consumption for driving, especially when the high-frequency small duty PWM driving adjusts the brightness, and thus the portion consumes a large amount of power consumption, in the embodiment of the application, the first switch unit 414 and the second switch unit 415 are controlled to be turned on or off by the brightness data, and under the condition of low brightness, the driving modules of all stages are not required to be in the working state, so that whether the driving modules work can be flexibly selected, and the power consumption of the LED driving circuit can be reduced.
In addition, in the LED driving circuit, the voltage value of the second end of the LED string light 1 determines the amount of the current source 4 loss in addition to the loss of the first driving transistor T1 and the second driving transistor T2, and since the minimum voltage of the second end of the LED string light 1 is equal to the reference voltage Vref, the reference voltage Vref in the embodiment of the application can be set according to the brightness, that is, when the brightness is low, the value of the reference voltage Vref can be made smaller, and correspondingly, the voltage of the second end of the LED string light 1 is made smaller, so that the power consumption of the LED driving circuit can be further reduced.
As shown in fig. 3 and fig. 7, in the embodiment of the present application, each single-path current source 41 can select drivers and driving tubes with different driving capabilities according to brightness data, and when a driving tube with smaller driving capability is selected, the duty ratio of PWM can be made lower, so that the dimming contrast of the PWM driven by the LED can be improved.
Based on the same inventive concept, the embodiment of the application also provides electronic equipment, which comprises the LED driving circuit provided by the embodiment of the application. Because the electronic device includes the LED driving circuit provided by the embodiment of the present application, the electronic device has the same beneficial effects as the LED driving circuit, and will not be described herein.
Specifically, the electronic device in the embodiment of the application can be electronic devices such as a notebook computer, a liquid crystal television, a liquid crystal display, an organic electronic display and the like.
Based on the same inventive concept, the embodiment of the application also provides a driving method of the above LED driving circuit, as shown in fig. 8, the method includes:
S101, a power supply conversion circuit receives brightness data output by a brightness control module and provides working voltages for all first ends according to the brightness data;
S102, the current source receives the brightness data output by the brightness control module, and outputs driving currents with different magnitudes to the LED lamp strings according to the brightness data.
In the embodiment of the application, when the minimum voltage in the voltages of the second ends is equal to the reference voltage Vref, the power conversion circuit 2 provides the working voltage VOUT for each first end, namely the LED lamp string 1, and because the value of the reference voltage Vref is output according to the brightness data, when the brightness is lower, the value of the reference voltage Vref can also be output smaller, so that the power consumption of the power conversion circuit 2 can be reduced, and the power consumption of the LED driving circuit can be further reduced.
The specific driving method of the LED driving circuit in the embodiment of the present application has been described above in the related manner, and will not be described here again.
In summary, by applying the embodiment of the application, at least the following beneficial effects can be achieved:
In the first embodiment of the present application, when the minimum voltage of the voltages at the plurality of second ends is equal to the reference voltage Vref, the power conversion circuit 2 provides the working voltage VOUT for each first end, that is, provides the working voltage for the LED string 1, and since the value of the reference voltage Vref is output according to the luminance data, when the luminance is lower, the value of the reference voltage Vref can also be output smaller, so that the power consumption of the power conversion circuit 2 can be reduced, and the power consumption of the LED driving circuit can be further reduced.
In the second embodiment of the present application, the first switch unit 414 and the second switch unit 415 are controlled to be turned on or off by the luminance data, so that the driving modules of all stages are not required to be in a working state under the condition of low luminance, and whether the driving modules work can be flexibly selected, thereby reducing the power consumption of the LED driving circuit.
In the third embodiment of the present application, since the minimum voltage at the second end of the LED string light 1 is equal to the reference voltage Vref, the reference voltage Vref in the embodiment of the present application can be set according to brightness, that is, when the brightness is low, the value of the reference voltage Vref can be made smaller, so that the power consumption of the LED driving circuit can be further reduced.
The terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present application, unless otherwise indicated, the meaning of "a plurality" is two or more.
The foregoing is only a partial embodiment of the present application, and it should be noted that it will be apparent to those skilled in the art that modifications and adaptations can be made without departing from the principles of the present application, and such modifications and adaptations are intended to be comprehended within the scope of the present application.

Claims (11)

1.一种LED驱动电路，其特征在于，包括：多路LED灯串、电源转换电路、亮度控制模块和电流源；1. An LED driving circuit, comprising: a multi-channel LED light string, a power conversion circuit, a brightness control module, and a current source; 每一路所述LED灯串均包括第一端和第二端；Each of the LED light strings includes a first end and a second end; 所述亮度控制模块，用于输出亮度数据给所述电源转换电路和所述电流源；亮度数据为数字信号；The brightness control module is used to output brightness data to the power conversion circuit and the current source; the brightness data is a digital signal; 电源转换电路，用于根据所述亮度数据输出参考电压，并实时接收所述第二端的电压，若多个所述第二端的电压中最小电压与所述参考电压相等，提供稳定的工作电压给各个所述第一端；否则，用于形成一反馈回路，所述反馈回路用于使得所述最小电压与所述参考电压相等；a power conversion circuit, configured to output a reference voltage based on the brightness data and receive the voltage of the second terminal in real time, and to provide a stable operating voltage to each of the first terminals if a minimum voltage among the plurality of voltages of the second terminals is equal to the reference voltage; otherwise, to form a feedback loop for ensuring that the minimum voltage is equal to the reference voltage; 所述电流源，包括若干单路电流源，一路所述单路电流源与一路所述LED灯串的第二端一一对应连接，每一路所述单路电流源用于根据所述亮度数据，输出不同大小的驱动电流；The current source includes a plurality of single-channel current sources, each of the single-channel current sources being connected to the second end of one of the LED light strings in a one-to-one correspondence, and each of the single-channel current sources being configured to output a driving current of different magnitudes according to the brightness data; 所述电流源包括第二数模转换电路，每一所述单路电流源包括一运算放大器和多级驱动模块；The current source includes a second digital-to-analog conversion circuit, and each of the single current sources includes an operational amplifier and a multi-stage driving module; 所述第二数模转换电路分别与所述亮度控制模块、各个所述运算放大器的同相输入端，以及除了每一所述单路电流源中的第一级驱动模块外的其余级驱动模块连接，用于接收所述亮度控制模块输出的亮度数据，将所述亮度数据转换为对应的亮度输入所述运算放大器的同相输入端，以及根据所述亮度数据，控制与该第二数模转换电路连接的所述驱动模块是否与所述运算放大器的反相输入端导通，以及控制与该第二数模转换电路连接的所述驱动模块是否与所述运算放大器的输出端导通；The second digital-to-analog conversion circuit is respectively connected to the brightness control module, the non-inverting input terminal of each of the operational amplifiers, and the remaining stage driving modules except the first stage driving module in each of the single current sources, and is used to receive brightness data output by the brightness control module, convert the brightness data into corresponding brightness data and input it into the non-inverting input terminal of the operational amplifier, and control whether the driving module connected to the second digital-to-analog conversion circuit is connected to the inverting input terminal of the operational amplifier, and control whether the driving module connected to the second digital-to-analog conversion circuit is connected to the output terminal of the operational amplifier according to the brightness data; 每一所述单路电流源中的其余级驱动模块的控制端通过第一开关单元与所述运算放大器的输出端连接，第一端与所述LED灯串的第二端连接，第二端通过第二开关单元与所述运算放大器的反相输入端连接，第三端接地；其中：The control end of the remaining stage driving modules in each of the single current sources is connected to the output end of the operational amplifier through a first switch unit, the first end is connected to the second end of the LED light string, the second end is connected to the inverting input end of the operational amplifier through a second switch unit, and the third end is grounded; wherein: 所述第一开关单元和所述第二开关单元，被配置为根据所述亮度数据导通或断开。The first switch unit and the second switch unit are configured to be turned on or off according to the brightness data. 2.根据权利要求1所述的LED驱动电路，其特征在于，所述电源转换电路包括：反馈接收电路和电源模块；2. The LED driving circuit according to claim 1, wherein the power conversion circuit comprises: a feedback receiving circuit and a power module; 所述反馈接收电路分别与所述亮度控制模块和每一路所述LED灯串的第二端连接，用于实时接收所述第二端的电压，在多个所述第二端的电压中选定一最小电压，并根据所述亮度控制模块输出的亮度数据输出参考电压，以及用于比较所述最小电压和所述参考电压，将比较结果输出给所述电源模块；The feedback receiving circuit is connected to the brightness control module and the second end of each LED light string, respectively, and is used to receive the voltage of the second end in real time, select a minimum voltage from a plurality of voltages of the second end, output a reference voltage according to the brightness data output by the brightness control module, and compare the minimum voltage with the reference voltage, and output the comparison result to the power supply module; 所述电源模块分别与电压输入端、所述反馈接收电路和每一路所述LED灯串的第一端连接，用于当比较结果为所述最小电压和所述参考电压相等时，提供稳定的工作电压给各个所述第一端；以及当比较结果为所述最小电压和所述参考电压不相等时，形成一反馈回路。The power supply module is respectively connected to the voltage input end, the feedback receiving circuit and the first end of each LED light string, and is used to provide a stable operating voltage to each first end when the comparison result shows that the minimum voltage and the reference voltage are equal; and to form a feedback loop when the comparison result shows that the minimum voltage and the reference voltage are not equal. 3.根据权利要求2所述的LED驱动电路，其特征在于，所述反馈接收电路包括：输出反馈网络、第一数模转换电路和误差放大器；3. The LED driving circuit according to claim 2, wherein the feedback receiving circuit comprises: an output feedback network, a first digital-to-analog conversion circuit, and an error amplifier; 所述输出反馈网络的输入端分别与各个所述第二端连接，输出端与所述误差放大器的反相输入端连接，用于在多个所述第二端的电压中选定一最小电压，将所述最小电压输入所述反相输入端；The input end of the output feedback network is connected to each of the second ends respectively, and the output end is connected to the inverting input end of the error amplifier, for selecting a minimum voltage among the voltages of the plurality of second ends and inputting the minimum voltage into the inverting input end; 所述第一数模转换电路的输入端与所述亮度控制模块连接，输出端与所述误差放大器的同相输入端连接，用于接收所述亮度控制模块输出的亮度数据，将所述亮度数据转换为对应的亮度，并根据所述亮度输出参考电压；The input end of the first digital-to-analog conversion circuit is connected to the brightness control module, and the output end is connected to the non-inverting input end of the error amplifier, and is used to receive the brightness data output by the brightness control module, convert the brightness data into corresponding brightness, and output a reference voltage according to the brightness; 所述误差放大器的输出端与所述电源模块连接，用于接收所述参考电压和所述最小电压，并比较所述最小电压和所述参考电压，将比较结果输出给所述电源模块。The output end of the error amplifier is connected to the power module, and is used for receiving the reference voltage and the minimum voltage, comparing the minimum voltage with the reference voltage, and outputting the comparison result to the power module. 4.根据权利要求3所述的LED驱动电路，其特征在于，所述电源模块包括：开关管、电感和续流二极管；4. The LED driving circuit according to claim 3, wherein the power supply module comprises: a switch tube, an inductor and a freewheeling diode; 所述开关管的控制端与所述误差放大器的输出端连接，第一极与所述电感的第一端连接，第二极接地设置；The control terminal of the switch tube is connected to the output terminal of the error amplifier, the first terminal is connected to the first terminal of the inductor, and the second terminal is grounded; 所述电感的第二端与所述电压输入端连接；The second end of the inductor is connected to the voltage input end; 所述续流二极管的正极与所述电感的第一端连接，负极与所述第一端连接。The anode of the freewheeling diode is connected to the first end of the inductor, and the cathode is connected to the first end. 5.根据权利要求1所述的LED驱动电路，其特征在于，每一所述单路电流源中的第一级驱动模块的控制端与所述运算放大器的输出端连接，第一端与所述LED灯串的第二端连接，第二端与所述运算放大器的反相输入端连接，第三端接地。5. The LED driving circuit according to claim 1, wherein the control terminal of the first-stage driving module in each of the single-channel current sources is connected to the output terminal of the operational amplifier, the first terminal is connected to the second terminal of the LED light string, the second terminal is connected to the inverting input terminal of the operational amplifier, and the third terminal is grounded. 6.根据权利要求5所述的LED驱动电路，其特征在于，每一所述单路电流源中的第一级驱动模块包括第一驱动晶体管和第一电阻；6. The LED driving circuit according to claim 5, wherein the first-stage driving module in each of the single-channel current sources comprises a first driving transistor and a first resistor; 所述第一驱动晶体管的控制端与所述运算放大器的输出端连接，第一极与所述LED灯串的第二端连接，第二极与所述运算放大器的反相输入端连接；The control terminal of the first driving transistor is connected to the output terminal of the operational amplifier, the first terminal is connected to the second terminal of the LED light string, and the second terminal is connected to the inverting input terminal of the operational amplifier; 所述第一电阻的第一端与所述第一驱动晶体管的第二极连接，第二端接地；A first end of the first resistor is connected to the second electrode of the first driving transistor, and a second end thereof is grounded; 每一所述单路电流源中的其余级驱动模块中，每一级驱动模块均包括第二驱动晶体管和第二电阻；In the remaining driving modules of each of the single current sources, each driving module includes a second driving transistor and a second resistor; 所述第二驱动晶体管的控制端通过所述第一开关单元与所述运算放大器的输出端连接，第一极与所述LED灯串的第二端连接，第二极通过所述第二开关单元与所述运算放大器的反相输入端连接；The control terminal of the second driving transistor is connected to the output terminal of the operational amplifier through the first switching unit, the first terminal is connected to the second terminal of the LED light string, and the second terminal is connected to the inverting input terminal of the operational amplifier through the second switching unit; 所述第二电阻的第一端与所述第二驱动晶体管的第二极连接，第二端接地。A first end of the second resistor is connected to the second electrode of the second driving transistor, and a second end of the second resistor is grounded. 7.根据权利要求6所述的LED驱动电路，其特征在于，每一所述单路电流源中的第一级驱动模块还包括第一高压驱动管和第一驱动器；7. The LED driving circuit according to claim 6, wherein the first-stage driving module in each single current source further comprises a first high-voltage driving tube and a first driver; 所述第一高压驱动管的控制端与电源连接，第一极与所述LED灯串的第二端连接，第二极与所述第一驱动晶体管的第一极连接；The control end of the first high-voltage driving tube is connected to the power supply, the first electrode is connected to the second end of the LED light string, and the second electrode is connected to the first electrode of the first driving transistor; 所述第一驱动器的第一端与所述运算放大器的输出端连接，第二端与所述第一驱动晶体管的控制端连接；A first terminal of the first driver is connected to the output terminal of the operational amplifier, and a second terminal of the first driver is connected to the control terminal of the first driving transistor; 每一所述单路电流源中的其余级驱动模块中，每一级驱动模块还包括第二高压驱动管和第二驱动器；In the remaining stage driving modules of each of the single current sources, each stage driving module further includes a second high-voltage driving tube and a second driver; 所述第二高压驱动管的控制端与电源连接，第一极与所述LED灯串的第二端连接，第二极与所述第二驱动晶体管的第一极连接；The control end of the second high-voltage driving tube is connected to the power supply, the first electrode is connected to the second end of the LED light string, and the second electrode is connected to the first electrode of the second driving transistor; 所述第二驱动器的第一端通过所述第一开关单元与所述运算放大器的输出端连接，第二端与所述第二驱动晶体管的控制端连接。A first end of the second driver is connected to the output end of the operational amplifier through the first switch unit, and a second end of the second driver is connected to the control end of the second driving transistor. 8.根据权利要求6或7所述的LED驱动电路，其特征在于，每一所述单路电流源还包括第三开关单元；8. The LED driving circuit according to claim 6 or 7, wherein each of the single current sources further comprises a third switch unit; 所述第三开关单元的第一端分别与所述第一驱动晶体管的控制端和所述第二驱动晶体管的控制端连接，第二端接地，控制端与脉冲调整信号的输出端连接，用于在脉冲调整信号的控制下导通或断开。The first end of the third switch unit is respectively connected to the control end of the first driving transistor and the control end of the second driving transistor, the second end is grounded, and the control end is connected to the output end of the pulse adjustment signal, and is used to be turned on or off under the control of the pulse adjustment signal. 9.根据权利要求1所述的LED驱动电路，其特征在于，还包括滤波电容，所述滤波电容的第一端与所述电源转换电路的输出端连接，第二端接地，用于对所述电源转换电路输出的电压进行滤波处理。9. The LED driving circuit according to claim 1, further comprising a filter capacitor, wherein a first end of the filter capacitor is connected to the output end of the power conversion circuit and a second end is grounded, and is used to filter the voltage output by the power conversion circuit. 10.一种电子设备，其特征在于，包括如权利要求1-9任一项所述的LED驱动电路。10. An electronic device, comprising the LED driving circuit according to any one of claims 1 to 9. 11.一种如权利要求1-9任一项所述的LED驱动电路的驱动方法，其特征在于，包括：11. A driving method of the LED driving circuit according to any one of claims 1 to 9, characterized by comprising: 所述电源转换电路接收所述亮度控制模块输出的亮度数据，根据所述亮度数据为各个所述第一端提供工作电压；The power conversion circuit receives the brightness data output by the brightness control module and provides a working voltage to each of the first terminals according to the brightness data; 所述电流源接收所述亮度控制模块输出的亮度数据，根据所述亮度数据，输出不同大小的驱动电流给所述LED灯串。The current source receives the brightness data output by the brightness control module, and outputs driving currents of different magnitudes to the LED light string according to the brightness data.
CN202210200177.0A 2022-03-02 2022-03-02 LED driving circuit, driving method thereof and electronic equipment Active CN114679812B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202210200177.0A CN114679812B (en) 2022-03-02 2022-03-02 LED driving circuit, driving method thereof and electronic equipment

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202210200177.0A CN114679812B (en) 2022-03-02 2022-03-02 LED driving circuit, driving method thereof and electronic equipment

Publications (2)

Publication Number Publication Date
CN114679812A CN114679812A (en) 2022-06-28
CN114679812B true CN114679812B (en) 2025-09-09

Family

ID=82072733

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202210200177.0A Active CN114679812B (en) 2022-03-02 2022-03-02 LED driving circuit, driving method thereof and electronic equipment

Country Status (1)

Country Link
CN (1) CN114679812B (en)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115148162B (en) * 2022-07-26 2023-03-24 北京显芯科技有限公司 Drive circuit, backlight circuit and display panel
CN115985255B (en) * 2022-12-20 2025-08-12 北京奕斯伟计算技术股份有限公司 Current drive device and display device
CN117411489B (en) * 2023-12-15 2024-08-23 深圳市山海半导体科技有限公司 Voltage output type digital-to-analog converter, driver thereof and electronic equipment

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104185350A (en) * 2014-09-12 2014-12-03 南京矽力杰半导体技术有限公司 Multi-way LED constant current driving circuit and control method thereof

Family Cites Families (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2005208241A (en) * 2004-01-21 2005-08-04 Nec Electronics Corp Light emitting element driving circuit
JP2008130295A (en) * 2006-11-17 2008-06-05 Matsushita Electric Works Ltd Led lighting circuit and illumination fixture using it
CN201349353Y (en) * 2009-01-19 2009-11-18 冠捷投资有限公司 Double-dimming backlight source driving device
JP2010218963A (en) * 2009-03-18 2010-09-30 Panasonic Electric Works Co Ltd Low-pressure discharge lamp lighting device and lighting apparatus using the same
US8334662B2 (en) * 2009-09-11 2012-12-18 Iwatt Inc. Adaptive switch mode LED driver
CN102802298B (en) * 2011-05-24 2016-01-20 瑞昱半导体股份有限公司 Be applied to function circuit and the correlation technique thereof of backlight
US20130026933A1 (en) * 2011-07-25 2013-01-31 Shenzhen China Star Optoelectronics Technology Co., Ltd. Led backlight drive circuit
US9030106B2 (en) * 2011-11-23 2015-05-12 Shenzhen China Star Optoelectronics Technology Co., Ltd. Driving circuit and LED backlight module using multiple references voltages
CN203352889U (en) * 2013-06-28 2013-12-18 成都芯源系统有限公司 LED driving device and control circuit thereof
US9084315B2 (en) * 2013-07-10 2015-07-14 Iml International Light-emitting diode lighting device having multiple driving stages
CN103796398B (en) * 2014-02-21 2016-01-06 南京矽力杰半导体技术有限公司 A kind of drive circuit of multi-path parallel LEDs lamp string and driving method
CN204350419U (en) * 2015-02-06 2015-05-20 无锡中星微电子有限公司 Many LED strip drive circuit
CN209643034U (en) * 2018-11-20 2019-11-15 华南理工大学 A four-channel AC drive chip circuit
CN113192457B (en) * 2019-06-10 2022-06-28 酷矽半导体科技(上海)有限公司 Drive circuit, drive chip, display system and display method
CN110831279B (en) * 2019-10-25 2024-12-24 深圳市晟碟半导体有限公司 LED driving device, driving circuit and driving method thereof
CN113727487B (en) * 2020-10-22 2023-06-23 杰华特微电子股份有限公司 Driving method and driving circuit for multi-channel LED lamp string
CN112382243A (en) * 2020-11-16 2021-02-19 成都中电熊猫显示科技有限公司 Driving circuit and method, backlight plate and display device

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104185350A (en) * 2014-09-12 2014-12-03 南京矽力杰半导体技术有限公司 Multi-way LED constant current driving circuit and control method thereof

Also Published As

Publication number Publication date
CN114679812A (en) 2022-06-28

Similar Documents

Publication Publication Date Title
CN114679812B (en) LED driving circuit, driving method thereof and electronic equipment
US8154223B2 (en) Driving apparatus of light emitting diode and driving method thereof
US7710049B2 (en) Driver and method for driving LEDS on multiple branch circuits
CN104883793B (en) A kind of multipath LED constant current drive circuit and driving method
US8018170B2 (en) Light emitting diode driving module
TWI477187B (en) Adaptive switch mode led system
US10140931B2 (en) Shadow mask assemblies and reusing methods of shadow mask assemblies thereof
CN103037597B (en) Multi-channel LED (Light Emitting Diode) constant current control circuit and LED light source control system
US8159148B2 (en) Light emitting diode light source module
CN107493635A (en) A kind of more pixel drive systems of LED
US11723122B2 (en) Dynamic driver voltage headroom adjustment
WO2014028722A1 (en) Led driver with boost converter current control
KR101778898B1 (en) Led backlight driving circuit and liquid crystal display
CN107317481B (en) Multi-stage DC-DC converter, power supply device and display equipment
JP2013109921A (en) Drive circuit for light-emitting element, and light-emitting device and electronic equipment using the same
CN109410848B (en) System and method for cascading dual controllers for LED backlight drive
CN114501699B (en) Dimming circuit, dimmer and LED lighting equipment
US8704457B2 (en) Power conversion circuit for light emitting diode
CN104602396A (en) WLED (White Light Emitting Diode) driver and driving control method thereof
CN113766701B (en) Adaptive linear dimming power supply system
CN111192553B (en) LED display screen driver chip and system
CN102956202A (en) Current control stage, constant current control system, and current control method
TWI407835B (en) Led circuit having led driving circuit and operation method of the same
CN102750907B (en) Image processing circuit and lighting module
TWI441141B (en) Current control stages, constant current control systems, and current control methods

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
CB02 Change of applicant information
CB02 Change of applicant information

Address after: 100176 Room 101, 1f, building 3, yard 18, Kechuang 10th Street, Beijing Economic and Technological Development Zone, Beijing

Applicant after: Beijing ESWIN Computing Technology Co.,Ltd.

Address before: 100176 Room 101, 1f, building 3, yard 18, Kechuang 10th Street, Beijing Economic and Technological Development Zone, Beijing

Applicant before: Beijing yisiwei Computing Technology Co.,Ltd.

GR01 Patent grant
GR01 Patent grant