LED driving circuit and luminaire

Abstract

The application provides an LED driving circuit and a lamp. The circuit comprises a rectifying module, a constant current driving module, a triac signal extraction module and a wireless communication module; the output ends of the rectifying module are connected with the input ends of the constant current driving module and the input end of the triac signal extraction module; the first signal input end of the wireless communication module is connected with the output end of the triac signal extraction module, the second signal input end is used for receiving the wireless dimming signal input by an external device, and the output end is connected with the control end of the constant current driving module; the wireless communication module is used for generating a target dimming signal based on the wireless dimming signal and the triac signal and sending the target dimming signal to the constant current driving module; the target dimming signal is obtained by the wireless communication module for compatible processing of the phase-cut dimming and the intelligent dimming, and then is sent to the constant current driving module for current control; the phase-cut dimmer and the wireless communication module exist simultaneously, and problems such as flashing light do not occur, the wireless communication module can be directly installed in the power path with the phase-cut dimmer, and the compatibility is good.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of LED, in particular to an LED driving circuit and a lamp. BACKGROUND

[0002] Triac dimming is a method of controlling LED brightness by adjusting the conduction phase of current, which is simple to realize and low in cost, and has been applied to incandescent lamp and energy-saving lamp dimming mode for a long time, and is also the most widely used dimming mode for LED dimming at present. With the development of LED technology, intelligent dimming products using wireless control are applied more and more widely.

[0003] In the prior art, since some users have installed triac dimmers in power lines, the wireless intelligent dimming product is directly installed in the original power line, and when the user adjusts the triac dimmer to a small angle, it will cause problems such as flashing light and non-lighting, and the wireless intelligent dimming product cannot be compatible with the triac dimmer. Therefore, when the wireless intelligent dimming product is installed, the existing power line needs to be modified, and the original triac dimmer needs to be removed, which is high in modification cost and is not conducive to the application and promotion of the wireless intelligent lighting product. SUMMARY

[0004] The embodiments of the present application provide an LED driving circuit and a lamp to solve the problem that the wireless control intelligent lighting product in the prior art cannot be compatible with the triac dimmer, and the original triac dimmer in the power line needs to be removed.

[0005] In a first aspect, the embodiments of the present application provide an LED driving circuit, comprising: an input end of the LED driving circuit is connected with an AC power supply through a triac dimmer, and an output end of the LED driving circuit is used to drive an LED load; the LED driving circuit comprises: a rectification module, a constant current driving module, a triac signal extraction module and a wireless communication module;

[0006] The input end of the rectification module is connected with the input end of the LED driving circuit, and the output end of the rectification module is connected with the input end of the constant current driving module and the input end of the triac signal extraction module respectively;

[0007] The first signal input end of the wireless communication module is connected with the output end of the triac signal extraction module, the second signal input end of the wireless communication module is used to receive a wireless dimming signal input by an external device, the output end of the wireless communication module is connected with the control end of the constant current driving module; the wireless communication module is used to acquire the wireless dimming signal and the triac signal sent by the triac signal extraction module, generate a target dimming signal based on the wireless dimming signal and the triac signal, and send the target dimming signal to the constant current driving module;

[0008] The output end of the constant current driving module is connected with the output end of the LED driving circuit, and is used for controlling the output current of the constant current driving module according to the target dimming signal.

[0009] Optionally, the target dimming signal is generated based on the wireless dimming signal and the switching signal, and is sent to the constant current driving module, and the method comprises:

[0010] The constant current reference current signal is generated according to the switching signal, the constant current reference current signal is multiplied by the wireless dimming signal to obtain the target dimming signal, and the target dimming signal is sent to the constant current driving module.

[0011] Optionally, the LED load comprises at least one LED lamp string; the constant current driving module comprises a positive driving end and at least one negative driving end, the number of the negative driving ends is the same as the number of the LED lamp strings; the positive driving end is connected with the positive poles of the LED lamp strings, and each negative driving end is connected with the negative pole of the corresponding LED lamp string one by one.

[0012] The constant current driving module comprises a first diode, a first resistor and a constant current driving chip.

[0013] The power supply end of the constant current driving chip is connected with the cathode of the first diode and the positive driving end through the first resistor, the control signal input end of the constant current driving chip is connected with the control end of the constant current driving module, and each drain driving end of the constant current driving chip is connected with each negative driving end one by one.

[0014] The anode of the first diode is connected with the input end of the constant current driving module.

[0015] The constant current driving chip is used for controlling the current of each drain driving end according to the target dimming signal.

[0016] Optionally, the constant current driving chip comprises a signal conditioning unit, at least one dimming control unit, at least one switch driving unit and at least one switch unit; each dimming control unit, each switch driving unit and each switch unit correspond one by one.

[0017] The input end of the signal conditioning unit is connected with the control signal input end of the constant current driving chip, and each output end of the signal conditioning unit is connected with the input end of each dimming control unit one by one; the signal conditioning unit is used for generating the secondary dimming signal corresponding to each dimming control unit according to the target dimming signal; wherein, the secondary dimming signal is a PWM signal.

[0018] The output end of any one dimming control unit is connected with the input end of the switch driving unit corresponding to the dimming control unit; the output end of the switch driving unit is connected with the control end of the corresponding switch unit; the first end of the switch unit is connected with the drain driving end corresponding to the dimming control unit, and the second end of the switch unit is grounded; the dimming control unit is used for generating the corresponding reference voltage according to the corresponding secondary dimming signal; the switch driving unit generates the corresponding switch control signal according to the reference voltage corresponding to the dimming control unit, and controls the switch unit to be turned on to realize the current control of the drain driving end corresponding to the dimming control unit through the switch control signal.

[0019] Optionally, the switch unit comprises a first switch tube and a second resistor.

[0020] The first end of the first switch tube is connected with the first end of the switch unit, the control end of the first switch tube is connected with the control end of the switch unit, and the second end of the first switch tube is connected with the second end of the switch unit through the second resistor.

[0021] Optionally, the switch driving unit comprises an error amplifier and a driving signal conditioning subunit.

[0022] The positive input end of the error amplifier is connected with the input end of the switch driving unit, the negative input end of the error amplifier is connected with the second end of the first switch tube and the second resistor respectively, and the output end of the error amplifier is connected with the input end of the driving signal conditioning subunit.

[0023] The output end of the driving signal conditioning subunit is connected with the output end of the switch driving unit.

[0024] Optionally, the number of the LED lamp string is one, and the target dimming signal is a PWM signal; the signal conditioning unit comprises a buffer and a third resistor.

[0025] The input end of the buffer is connected with the input end of the signal conditioning unit, and the output end of the buffer is connected with the output end of the signal conditioning unit through the third resistor.

[0026] Optionally, the cut-off signal extraction module comprises a fourth resistor.

[0027] The first end of the fourth resistor is connected with the input end of the cut-off signal extraction module, and the second end of the fourth resistor is connected with the output end of the cut-off signal extraction module.

[0028] Optionally, the LED driving circuit further comprises a constant voltage module.

[0029] The input end of the constant voltage module is connected with the output end of the rectifier module and the input end of the cut-off signal extraction module respectively, and the output end of the constant voltage module is connected with the input end of the constant current driving module.

[0030] The voltage at the output end of the constant voltage module is constant.

[0031] In a second aspect, the embodiment of the present application provides a lamp, which comprises the LED driving circuit provided in the first aspect of the above embodiment.

[0032] The embodiment of the present application provides an LED driving circuit and a lamp. The LED driving circuit comprises: an input end of the LED driving circuit is connected with an alternating current power supply through a silicon controlled dimmer, and an output end of the LED driving circuit is used for driving an LED load; the LED driving circuit comprises: a rectifying module, a constant current driving module, a triac signal extraction module and a wireless communication module; an input end of the rectifying module is connected with the input end of the LED driving circuit, and output ends of the rectifying module are connected with an input end of the constant current driving module and an input end of the triac signal extraction module respectively; a first signal input end of the wireless communication module is connected with an output end of the triac signal extraction module, a second signal input end of the wireless communication module is used for receiving a wireless dimming signal input by an external device, and an output end of the wireless communication module is connected with a control end of the constant current driving module; the wireless communication module is used for acquiring the wireless dimming signal and a triac signal sent by the triac signal extraction module, generating a target dimming signal based on the wireless dimming signal and the triac signal, and sending the target dimming signal to the constant current driving module; an output end of the constant current driving module is connected with the output end of the LED driving circuit, and is used for controlling an output current of the constant current driving module according to the target dimming signal. In the embodiment of the present application, the wireless communication module receives the wireless dimming signal sent by the external device, simultaneously acquires the triac signal through the triac signal extraction module, sends the triac signal and the dimming signal to the constant current driving module for dimming control after compatible processing, so that the user can adjust through the silicon controlled dimmer or intelligent dimming (mobile phone APP or remote controller), and the problem of flashing light does not occur, so that the LED driving circuit can be compatible with the silicon controlled dimmer, can be directly installed in a power line with the silicon controlled dimmer, does not need to be reformed on the original power line, and the adaptability and compatibility of the circuit are improved. BRIEF DESCRIPTION OF DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor.

[0034] Figure 1 is a circuit structure schematic diagram of an LED driving circuit provided by the embodiment of the present application;

[0035] Figure 2 is a circuit structure schematic diagram of another LED driving circuit provided by the embodiment of the present application;

[0036] Figure 3 is a circuit schematic diagram of an LED driving circuit provided by an embodiment of the present application;

[0037] Figure 4 is an internal structure block diagram of a constant current driving chip provided by an embodiment of the present application;

[0038] Figure 5 is an internal principle schematic diagram of a three-way output constant current driving chip provided by an embodiment of the present application;

[0039] Figure 6 is an internal principle schematic diagram of a one-way output constant current driving chip provided by an embodiment of the present application;

[0040] Figure 7 is a circuit structure schematic diagram of another LED driving circuit provided by an embodiment of the present application;

[0041] Figure 8 is a circuit principle diagram of a constant voltage module provided by an embodiment of the present application. DETAILED DESCRIPTION

[0042] In order to make the personnel in the technical field better understand the present application, the technical solutions in the embodiments of the present application will be clearly described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work should fall within the protection scope of the present application.

[0043] The terms “include” and other any variants thereof in the specification and claims of the present application and the above-described drawings mean “include but not limited to”, and are intended to cover non-exclusive inclusion, and are not limited to the examples listed in the text. In addition, the terms “first” and “second” and the like are used to distinguish different objects, rather than to describe a specific order.

[0044] The implementation of the present application will be described in detail below with reference to the specific drawings:

[0045] Figure 1 is a structure schematic diagram of an LED driving circuit provided by an embodiment of the present application. The input end of the LED driving circuit is connected with an AC power source through a thyristor dimmer, and the output end of the LED driving circuit is used to drive an LED load;

[0046] Referring to Figure 1 , the LED driving circuit comprises a rectification module 11, a constant current driving module 12, a phase-cut signal extraction module 13 and a wireless communication module 14;

[0047] The input end of the rectifier module 11 is connected with the input end of the LED driving circuit, the output end of the rectifier module 11 is connected with the input end of the constant current driving module 12 and the input end of the triac signal extraction module 13 respectively;

[0048] The first signal input end of the wireless communication module 14 is connected with the output end of the triac signal extraction module 13, the second signal input end of the wireless communication module 14 is used for receiving the wireless dimming signal input by the external device, and the output end of the wireless communication module 14 is connected with the control end of the constant current driving module 12; the wireless communication module 14 is used for acquiring the wireless dimming signal and the triac signal sent by the triac signal extraction module 13, generating the target dimming signal based on the wireless dimming signal and the triac signal, and sending the target dimming signal to the constant current driving module 12.

[0049] The output end of the constant current driving module 12 is connected with the output end of the LED driving circuit, and is used for controlling the output current of the constant current driving module 12 according to the target dimming signal.

[0050] The triac signal represents the angle of the triac dimmer, and the reference current is adjusted. If the compatibility of the dimming signal is not processed, when the user adjusts the triac dimmer, the reference current changes, and the constant current driving module 12 still processes according to the initial reference current, which will cause abnormal dimming and cause flash light and the like.

[0051] In the embodiment of the application, the reference Figure 1 The wireless communication module 14 acquires the wireless dimming signal sent by the external device (for example, a mobile phone APP or a remote controller), and acquires the triac signal through the triac signal extraction module 13, and the compatibility of the two is processed to obtain the target dimming signal to control the constant current driving module 12 to perform constant current driving, so that the triac dimmer can accurately perform constant current control whether it is in a large angle or a small angle, and the problem of flash light in a small angle does not occur, and the compatibility of the driving circuit is effectively improved. At the same time, the user can use the triac dimmer and the wireless intelligent dimming at the same time to adjust, so as to meet different dimming needs of the user. The driving circuit can also be directly installed on the power line installed with the triac dimmer, without the need to remove the original triac dimmer, and the installation is simple, and the adaptability of the driving circuit is improved.

[0052] In a possible implementation, the target dimming signal is generated based on the wireless dimming signal and the triac signal, and is sent to the constant current driving module 12, which can include:

[0053] The constant current reference current signal is generated according to the triac signal, the constant current reference current signal is multiplied by the wireless dimming signal to obtain the target dimming signal, and the target dimming signal is sent to the constant current driving module 12.

[0054] In the embodiment of the present application, the angle of the triac of the triac dimmer is controlled, and the angle of the triac determines the size of the reference current. In the existing constant current driving architecture, the default reference current is constant. When the angle of the triac changes, the size of the reference current changes. The reference current is not compatible with the original parameters in the constant current driving module 12, and therefore problems such as small-angle flashing may occur. Based on this, in the embodiment of the present application, the constant current reference current signal and the wireless dimming signal are multiplied to dynamically adjust the size of the reference current, so that the parameters of the constant current driving architecture are compatible with the actual size of the reference current, and the compatibility of the LED driving circuit is improved.

[0055] In a possible implementation, the reference Figure 2 The LED load can include at least one LED light string, and the constant current driving module 12 can include a positive driving end and at least one negative driving end, the number of negative driving ends being the same as the number of LED light strings. The positive driving end is connected to the positive poles of the LED light strings, and each negative driving end is connected to the negative pole of the corresponding LED light string.

[0056] The reference Figure 3 The constant current driving module 12 can include a first diode D1, a first resistor R1, and a constant current driving chip U1.

[0057] The power supply end of the constant current driving chip U1 is connected to the cathode and the positive driving end of the first diode D1 through the first resistor R1. The control signal input end of the constant current driving chip U1 is connected to the control end of the constant current driving module 12. Each drain driving end of the constant current driving chip U1 is connected to each negative driving end in one-to-one correspondence.

[0058] The anode of the first diode D1 is connected to the input end of the constant current driving module 12.

[0059] The constant current driving chip U1 is configured to control the current of each drain driving end according to the target dimming signal.

[0060] To achieve dimming and color adjustment, multiple LED light strings are usually provided. For example, the reference Figure 3 The LED light string is three-way, and is an RGB light source. The three-way LED light string is mixed to achieve dimming and color adjustment. In the embodiment of the present application, the constant current driving chip U1 allocates the current of each LED light string, that is, the current of each drain driving end, according to the target dimming signal, to achieve precise dimming.

[0061] The first diode D1 is configured to be unidirectionally conductive, to avoid affecting the front end by the rear end signal, thereby affecting the accuracy of the triac signal extraction. The first resistor R1 is configured to supply power for the constant current driving chip U1.

[0062] Other peripheral devices are described with reference toFigure 3 , which will not be described in detail here, is a conventional setting in the art.

[0063] In a possible implementation, the rectifier module 11 can include a rectifier bridge BD1, which will be described in detail with reference to Figure 3 .

[0064] With reference to Figure 3 , a fuse FR1 can also be arranged between the rectifier module 11 and the triac for overcurrent protection.

[0065] In a possible implementation, with reference to Figure 4 , the constant current drive chip U1 can include a signal conditioning unit 121, at least one dimming control unit 122 (DIM Control), at least one switch drive unit 123, and at least one switch unit 124; each dimming control unit 122, each switch drive unit 123, and each switch unit 124 correspond one-to-one;

[0066] The input end of the signal conditioning unit 121 is connected to the control signal input end of the constant current drive chip U1, and each output end of the signal conditioning unit 121 is connected to the input end of each dimming control unit 122 one-to-one; the signal conditioning unit 121 is configured to generate a secondary dimming signal corresponding to each dimming control unit 122 according to a target dimming signal; wherein the secondary dimming signal is a PWM signal;

[0067] For any one dimming control unit 122, the output end of the dimming control unit 122 is connected to the input end of the switch drive unit 123 corresponding to the dimming control unit 122; the output end of the switch drive unit 123 is connected to the control end of the corresponding switch unit 124; the first end of the switch unit 124 is connected to the drain driving end corresponding to the dimming control unit 122, and the second end of the switch unit 124 is grounded; the dimming control unit 122 is configured to generate a corresponding reference voltage according to the corresponding secondary dimming signal; the switch drive unit 123 generates a corresponding switch control signal according to the reference voltage corresponding to the dimming control unit 122, and controls the switch unit 124 to be turned on through the switch control signal to realize the control of the current of the drain driving end corresponding to the dimming control unit 122.

[0068] For the constant current drive chip U1, the signal conditioning unit 121 is configured to adjust the target dimming signal, for example, when the LED lamp string is two or more than two, the target dimming signal is an I 2 C signal, and the signal conditioning unit 121 adjusts the I 2The C signal is converted into a second-stage dimming signal (PWM signal) corresponding to each LED lamp string. The dimming control unit 122 generates a reference voltage (VRef1, VRef2, VRef3) according to the second-stage dimming signal, and the reference voltage reflects the size of the current at the drain driving end; the switch driving unit 123 controls the switch unit 124 to be turned on according to the reference voltage, and controls the size of the current at the drain driving end.

[0069] In a possible implementation, the switch unit 124 can include a first switch tube Q1 and a second resistor R2. Figure 5 Figure 6 The first end of the first switch tube Q1 is connected with the first end of the switch unit 124, the control end of the first switch tube Q1 is connected with the control end of the switch unit 124, and the second end of the first switch tube Q1 is connected with the second end of the switch unit 124 through the second resistor R2.

[0070] The first switch tube Q1 is used to form the switch unit 124 in the constant-current driving chip U1, and the chip process is good.

[0071] It should be noted that the above embodiment is only one implementation, and the first switch tube Q1 and the second resistor R2 can also not be integrated in the constant-current driving chip U1, but be realized by an external connection, which is not limited in detail.

[0072] In a possible implementation, the switch driving unit 123 can include an error amplifier EA and a driving signal conditioning subunit Control.

[0073] The positive input end of the error amplifier EA is connected with the input end of the switch driving unit 123, the negative input end of the error amplifier EA is connected with the second end of the first switch tube Q1 and the second resistor R2 respectively, and the output end of the error amplifier EA is connected with the input end of the driving signal conditioning subunit Control. Figure 5 Figure 6 The output end of the driving signal conditioning subunit Control is connected with the output end of the switch driving unit 123.

[0074] The output end of the driving signal conditioning subunit Control is connected with the output end of the switch driving unit 123.

[0075] The output end of the driving signal conditioning subunit Control is connected with the output end of the switch driving unit 123.

[0076] ​​In the embodiment of the present application, the current of the drain driving end is controlled by the reference voltage (VRef1, VRef2, VRef3), and the current of the drain driving end is proportional to the reference voltage. When the current of the drain driving end does not reach the preset current, the error amplifier EA amplifies the error and outputs a high level to increase the on-duty ratio of the first switch tube Q1 and increase the current of the drain driving end. Conversely, when the current of the drain driving end does not reach the preset current, the error amplifier EA also amplifies the error but outputs a low level to reduce the on-duty ratio of the first switch tube Q1 and reduce the current of the drain driving end, thereby realizing the adjustment of the current of each drain driving end.

[0077] In a possible implementation, the reference Figure 6 , the number of LED lamp strings is one, and the target dimming signal is a PWM signal; the signal conditioning unit 121 includes a buffer Buffer and a third resistor R3.

[0078] The input end of the buffer Buffer is connected with the input end of the signal conditioning unit 121, and the output end of the buffer Buffer is connected with the output end of the signal conditioning unit 121 through the third resistor R3.

[0079] When the target dimming signal is a PWM signal, the signal does not need to be converted, so only the third resistor R3 and the buffer Buffer are needed to perform signal buffering, thereby improving the stability and reliability of the signal.

[0080] When the LED lamp string is multiple, for example, the reference Figure 5 , the number of LED lamp strings is three, and the target dimming signal can be an I 2 C signal, a special chip needs to be arranged to process the I 2 C signal, and the specific circuit of the signal conditioning unit 121 can refer to Figure 5 , which is a conventional technical means and will not be described in detail here.

[0081] It should be noted that the number of drain driving ends of the constant current driving chip can be adjusted according to actual application requirements; for example, Figure 5 shows the internal block diagram of a chip with three drain driving ends, Figure 6 shows the internal block diagram of a chip with one drain driving end.

[0082] Meanwhile, the internal power supply and ground of the chip are all conventional technical means, and will not be described in detail here.

[0083] In a possible implementation, the reference Figure 3 , the chopping signal extraction module 13 can include a fourth resistor R4.

[0084] A first end of the fourth resistor R4 is connected with an input end of the phase-cut signal extraction module 13, and a second end of the fourth resistor R4 is connected with an output end of the phase-cut signal extraction module 13.

[0085] In a possible implementation, referring to Figure 7 , the LED driving circuit can further include a constant voltage module 15.

[0086] An input end of the constant voltage module 15 is connected with an output end of the rectifier module 11 and an input end of the phase-cut signal extraction module 13 respectively, and an output end of the constant voltage module 15 is connected with an input end of the constant current driving module 12.

[0087] The voltage of the output end of the constant voltage module 15 is constant.

[0088] The constant voltage module 15 is arranged in the embodiment of the present application to control the power supply voltage of the LED, and the stability of the LED driving circuit is improved. The specific circuit principle diagram of the constant voltage module 15 is referred to Figure 8 , and will not be described here in detail.

[0089] In a possible implementation, referring to Figure 7 , the LED driving circuit can further include an auxiliary power supply module 16.

[0090] An input end of the auxiliary power supply module 16 is connected with an output end of the rectifier module 11, and is used to supply power for the wireless communication module 14.

[0091] Corresponding to the above-mentioned embodiments, the embodiment of the present application provides a lamp, which includes the LED driving circuit provided by any one of the above-mentioned embodiments, and has the advantages of the LED driving circuit, and will not be described here in detail.

[0092] The above-mentioned embodiments are only used to illustrate the technical solutions of the present application, and not to limit the same; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: the technical solutions recorded in the foregoing embodiments can still be modified, or some technical features can be replaced equivalently; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. An LED driving circuit, characterized in that, include: The input terminal of the LED driver circuit is connected to the AC power supply through a silicon controlled rectifier (SCR) dimmer, and the output terminal of the LED driver circuit is used to drive the LED load. The LED driving circuit includes: a rectifier module, a constant current driving module, a phase-cutting signal extraction module, and a wireless communication module; The input terminal of the rectifier module is connected to the input terminal of the LED driver circuit, and the output terminal of the rectifier module is connected to the input terminal of the constant current driver module and the input terminal of the phase-cut signal extraction module, respectively. The first signal input terminal of the wireless communication module is connected to the output terminal of the phase-cut signal extraction module, the second signal input terminal of the wireless communication module is used to receive the wireless dimming signal input from the external device, and the output terminal of the wireless communication module is connected to the control terminal of the constant current drive module; the wireless communication module is used to acquire the wireless dimming signal and the phase-cut signal sent by the phase-cut signal extraction module, generate a target dimming signal based on the wireless dimming signal and the phase-cut signal, and send it to the constant current drive module; The output terminal of the constant current driving module is connected to the output terminal of the LED driving circuit, and is used to control the output current of the constant current driving module according to the target dimming signal. The step of generating a target dimming signal based on the wireless dimming signal and the phase-cutting signal, and sending it to the constant current drive module, includes: A constant current reference current signal is generated based on the phase-cutting signal. The constant current reference current signal is multiplied by the wireless dimming signal to obtain the target dimming signal, which is then sent to the constant current drive module.

2. The LED driving circuit as described in claim 1, characterized in that, The LED load includes at least one LED string; the constant current driving module includes a positive driving terminal and at least one negative driving terminal, the number of negative driving terminals being the same as the number of LED strings; the positive driving terminal is connected to the positive terminal of each LED string, and each negative driving terminal is connected to the negative terminal of each LED string in turn. The constant current driving module includes: a first diode, a first resistor, and a constant current driving chip; The power supply terminal of the constant current driving chip is connected to the cathode of the first diode and the positive driving terminal of the first diode through the first resistor. The control signal input terminal of the constant current driving chip is connected to the control terminal of the constant current driving module. Each drain driving terminal of the constant current driving chip is connected to each negative driving terminal in a corresponding manner. The anode of the first diode is connected to the input terminal of the constant current drive module; The constant current driver chip is used to control the current at each drain drive terminal according to the target dimming signal.

3. The LED driving circuit as described in claim 2, characterized in that, The constant current driving chip includes: a signal conditioning unit, at least one dimming control unit, at least one switch driving unit, and at least one switch unit; each dimming control unit, each switch driving unit, and each switch unit corresponds to one other; The input terminal of the signal conditioning unit is connected to the control signal input terminal of the constant current drive chip, and each output terminal of the signal conditioning unit is connected to the input terminal of each dimming control unit respectively; the signal conditioning unit is used to generate secondary dimming signals corresponding to each dimming control unit according to the target dimming signal; wherein, the secondary dimming signal is a PWM signal; For any dimming control unit, the output terminal of the dimming control unit is connected to the input terminal of the corresponding switch driver unit; the output terminal of the switch driver unit is connected to the control terminal of the corresponding switch unit; the first terminal of the switch unit is connected to the drain driver terminal of the dimming control unit, and the second terminal of the switch unit is grounded; the dimming control unit is used to generate a corresponding reference voltage according to the corresponding secondary dimming signal; the switch driver unit generates a corresponding switch control signal according to the reference voltage of the dimming control unit, and controls the switch unit to conduct through the switch control signal to control the current of the drain driver terminal of the dimming control unit.

4. The LED driving circuit as described in claim 3, characterized in that, The switching unit includes: a first switching transistor and a second resistor; The first terminal of the first switching transistor is connected to the first terminal of the switching unit, the control terminal of the first switching transistor is connected to the control terminal of the switching unit, and the second terminal of the first switching transistor is connected to the second terminal of the switching unit through the second resistor.

5. The LED driving circuit as described in claim 4, characterized in that, The switch driving unit includes: an error amplifier and a driving signal conditioning subunit; The positive input terminal of the error amplifier is connected to the input terminal of the switch driving unit, the negative input terminal of the error amplifier is connected to the second terminal of the first switch and the second resistor respectively, and the output terminal of the error amplifier is connected to the input terminal of the drive signal conditioning subunit. The output terminal of the drive signal conditioning subunit is connected to the output terminal of the switch drive unit.

6. The LED driving circuit as described in claim 3, characterized in that, The LED string is a single channel, and the target dimming signal is a PWM signal; the signal conditioning unit includes a buffer and a third resistor. The input terminal of the buffer is connected to the input terminal of the signal conditioning unit, and the output terminal of the buffer is connected to the output terminal of the signal conditioning unit through the third resistor.

7. The LED driving circuit as described in claim 1, characterized in that, The phase-cut signal extraction module includes: a fourth resistor; The first end of the fourth resistor is connected to the input end of the phase-cut signal extraction module, and the second end of the fourth resistor is connected to the output end of the phase-cut signal extraction module.

8. The LED driving circuit as described in claim 1, characterized in that, The LED driving circuit also includes: a constant voltage module; The input terminal of the constant voltage module is connected to the output terminal of the rectifier module and the input terminal of the phase-cut signal extraction module, respectively, and the output terminal of the constant voltage module is connected to the input terminal of the constant current drive module. The voltage at the output terminal of the constant voltage module is constant.

9. A lamp, characterized in that, Includes the LED driving circuit as described in any one of claims 1 to 8.

Images