CN201967204U

CN201967204U - Multi-output constant-current driving circuit of light-emitting diode

Info

Publication number: CN201967204U
Application number: CN2011200039361U
Authority: CN
Inventors: 葛良安; 姚晓莉; 华桂潮; 柳杨
Original assignee: Inventronics Hangzhou Co Ltd
Current assignee: Led One Hangzhou Co Ltd
Priority date: 2011-01-07
Filing date: 2011-01-07
Publication date: 2011-09-07
Anticipated expiration: 2021-01-07

Abstract

The utility model provides a multi-output constant-current driving circuit of a light-emitting diode. The circuit comprises a constant-current source and at least two load branch circuits, wherein at least one load branch circuit serves as a reference branch circuit and the other load branch circuits or part of the other load branch circuits serve as regulating branch circuits; a current sampling module is arranged for each reference branch circuit; a current regulating module and a current regulating control module are arranged for each regulating branch circuit; and the current regulating control module is used for receiving a current sampling signal of the current sampling module of each reference branch circuit connected with the current regulating control module as a first signal, receiving the current sampling signals of the current regulating modules of the regulating branch circuits as second signals, controlling the impedance of the current regulating module of the regulating branch circuits which are connected with the current regulating control module, and regulating the current of the regulating branch circuits connected with the current regulating control module. The circuit provided by the utility model has the advantages of simple structure and lower cost.

Description

A kind of LED constant current driving circuit of many outputs

Technical field

The utility model relates to circuit of LED, particularly relates to a kind of LED constant current driving circuit of many outputs.

Background technology

In light-emitting diode (LED, the Light Emitting Diode) constant-current drive circuit of multichannel output, the load of every road is made up of one or more LED lamps.

In the prior art, adopt the form of constant voltage module+multichannel DC/DC constant-current circuit to constitute the LED constant current control Driver Circuit that multichannel is exported usually, as shown in Figure 1.

The described drive circuit of Fig. 1 comprises: a constant voltage module and several non-isolation DCs/DC constant-current circuit.Each non-isolation DC/DC constant-current circuit all connects the output of described constant voltage module, is respectively applied for to drive a paths of LEDs load.This DC/DC constant-current circuit can be the high frequency conversion circuit of BUCK one class, also can adjust circuit for linearity.

The output of described constant voltage module is as the input of multiple constant current circuit.Every road constant-current circuit is done constant current control separately, the size of current on every road can independently be set as required, thereby regulate the brightness of each paths of LEDs load, realizes the color of led light source or the adjusting of colour temperature.

But there is following shortcoming in the LED constant current control Driver Circuit of the described multichannel of prior art output: need a DC/DC constant-current circuit all be set for every paths of LEDs load, make circuit complexity, cost higher.

The utility model content

The purpose of this utility model provides a kind of LED constant current driving circuit of many outputs, and it is simple in structure and cost is lower.

For achieving the above object, the utility model provides following scheme: a kind of LED constant current driving circuit of many outputs, and described circuit comprises: a constant-current source; Described constant-current source has two-way load branch at least;

As the reference branch road, all the other all or part of load branch are for regulating branch road with at least one road load branch;

For every road reference arm is provided with a current sample module respectively; The LED load series connection of described current sample module and reference arm is at the output of described constant-current source;

Regulate branch road for every road one current regulating module and current regulation control module are set respectively; Described current regulating module and the output of the LED load series connection of regulating branch road at described constant-current source;

First signal input part of described current regulation control module directly connects or connects at least one road reference arm by resistance, the secondary signal input termination one tunnel of described current regulation control module is regulated branch road, the current regulating module of the adjusting branch road that the output termination of described current regulation control module is attached thereto;

Described current regulation control module, the current sampling signal of current sample module that is used to receive each reference arm that is attached thereto is as first signal, with the current sampling signal of the current regulating module of receive regulating branch road as secondary signal, the impedance of the current regulating module of the adjusting branch road that control is attached thereto, the electric current of the adjusting branch road that adjusting is attached thereto.

Preferably, described first signal and described secondary signal have the common reference end, and described common reference end is the negative output terminal of constant-current source;

Described current regulating module comprises: first operational amplifier, compensating network;

First signal is input to the in-phase input end of described first operational amplifier, and secondary signal is input to the inverting input of described first operational amplifier, and the output of described first operational amplifier is as the output of described current regulation control module;

Described compensating network is connected between the inverting input and output of described operational amplifier.

Described current regulation control module comprises: first operational amplifier, compensating network, the 5th adjustable resistance;

One end of described the 5th adjustable resistance is as first signal input part of described current regulation control module, another termination common reference end of described the 5th adjustable resistance;

The in-phase input end of described first operational amplifier connects the sliding end of described the 5th adjustable resistance, secondary signal is input to the inverting input of described first operational amplifier, and the output of described first operational amplifier is as the output of described current regulation control module;

Described compensating network is connected between the inverting input and output of described first operational amplifier.

Described current regulation control module comprises: first operational amplifier, compensating network, the 6th resistance, filter unit, first metal-oxide-semiconductor;

One end of described the 6th resistance is as first signal input part of described current regulation control module, the drain electrode of described first metal-oxide-semiconductor of another termination of described the 6th resistance; The source electrode of described first metal-oxide-semiconductor connects the common reference end, and the gate pole of described first metal-oxide-semiconductor connects control signal;

The input of described filter unit connects the drain-source utmost point of described first metal-oxide-semiconductor, the in-phase input end of the first output termination, first operational amplifier of described filter unit, the second output termination common reference end of described filter unit;

Secondary signal is input to the inverting input of described first operational amplifier, and the output of described first operational amplifier is as the output of described current regulation control module;

Preferably, described current sample module is a resistance.

Preferably, described current regulating module is that a resistance and one is adjusted pipe; Described resistance and the series connection of described adjustment pipe; Described resistance be used to the to sample electric current of this adjusting branch road.

Preferably, be in series with switching tube on the output bus of described constant-current source.

Preferably, when the first input end of described current regulation control module is connected to few two-way reference arm, for every road reference arm is provided with a current-sharing unit; The LED load series connection of described current-sharing unit and described current sample module, reference arm is between described constant-current source and ground;

The first input end of described current regulation control module links to each other with each reference arm by a resistance respectively.

The utility model also provides a kind of LED constant current driving circuit of many outputs, and described circuit comprises: a constant-current source; Described constant-current source has two-way load branch at least; Wherein at least one load branch is for regulating branch road;

Regulate branch road for each one current regulating module and current regulation control module are set respectively; Described current regulating module is connected with the LED load of regulating branch road, and one of described series arm terminates at an output of described constant-current source, and the other end connects another output of constant-current source by the total current sample circuit;

Described total current sample circuit output total current sampled signal;

First signal input part of described current regulation control module connects described total current sample circuit, the secondary signal input termination one tunnel of described current regulation control module is regulated branch road, the current regulating module of the adjusting branch road that the output termination of described current regulation control module is attached thereto;

Described current regulating module, the current sampling signal of the current regulating module of the adjusting branch road that is used to receive the total load current sampled signal of described constant-current source output and is attached thereto, the impedance of the current regulating module of the adjusting branch road that control is attached thereto, the electric current of the adjusting branch road that adjusting is attached thereto.

Preferably, described total current sample circuit comprises the 12 resistance, and the described the 12 ohmically voltage is the total current sampled signal;

Described current regulation control module comprises:

The inverting input of four-operational amplifier connects an end of described the 12 resistance through the 15 resistance, the normal phase input end of described four-operational amplifier connects the other end of described the 12 resistance, the normal phase input end of output termination the 3rd operational amplifier of described four-operational amplifier through the 14 resistance;

The 16 resistance string is connected between the inverting input and output of described four-operational amplifier; The 13 resistance string is connected between the reference ground of the normal phase input end of described four-operational amplifier and described four-operational amplifier;

The inverting input of described the 3rd operational amplifier connects described adjusting branch road, the control end of the current regulating module of the described adjusting branch road of output termination of described the 3rd operational amplifier;

Compensating network is connected between the inverting input and output of described the 3rd operational amplifier.

Described current regulation control module comprises:

Two stiff ends of the 17 adjustable resistance are connected on the 12 resistance two ends respectively;

The inverting input of four-operational amplifier connects the adjustable end of described the 17 adjustable resistance through the 15 resistance, the normal phase input end of described four-operational amplifier connects a stiff end of the 17 resistance, the normal phase input end of output termination the 3rd operational amplifier of described four-operational amplifier through the 14 resistance;

Described current regulation control module comprises:

The hot end of described the 12 resistance of one termination of the 18 resistance, the drain electrode of another termination second metal-oxide-semiconductor of described the 18 resistance, the source electrode of described second metal-oxide-semiconductor connects the cold end of described the 12 resistance, and the gate pole of described second metal-oxide-semiconductor connects control signal;

Two inputs of filter unit connect the drain-source utmost point of described second metal-oxide-semiconductor respectively, an output of described filter unit connects the reversed-phase output of four-operational amplifier through the 15 resistance, and another output of described filter unit connects the normal phase input end of four-operational amplifier through the 14 resistance;

The normal phase input end of output termination the 3rd operational amplifier of described four-operational amplifier;

The inverting input of described the 3rd operational amplifier connects described adjustable branch road, the control end of the current regulating module of the described adjustable branch road of output termination of described the 3rd operational amplifier;

Described compensating network is connected between the inverting input and output of described the 3rd operational amplifier.

According to the specific embodiment that the utility model provides, the utility model discloses following technique effect:

The LED constant current driving circuit of the described many outputs of the utility model embodiment, with the sampled signal of the current sampling signal of at least one paths of LEDs load branch or total load current as the reference signal, with the current sampling signal of described reference signal and the load branch that is conditioned input signal as the current regulation control module, utilize the size of the impedance of the load branch that the output signal control of described current regulation control module is conditioned, thus the size of current of regulating this road load branch.Need compare for every paths of LEDs load all is provided with a DC/DC constant-current circuit with prior art, the described circuit of the utility model embodiment only need be provided with the current regulation control module for the load branch that is conditioned, and makes that circuit structure is simple and cost is lower.

Description of drawings

In order to be illustrated more clearly in the utility model embodiment or technical scheme of the prior art, to do to introduce simply to the accompanying drawing of required use among the embodiment below, apparently, accompanying drawing in describing below only is embodiment more of the present utility model, for those of ordinary skills, under the prerequisite of not paying creative work, can also obtain other accompanying drawing according to these accompanying drawings.

Fig. 1 is the LED constant current control Driver Circuit figure of the multichannel output of prior art;

Fig. 2 is the LED constant current driving circuit figure of many outputs of the utility model embodiment one;

Fig. 3 is the LED constant current driving circuit figure of many outputs of the utility model embodiment two;

Fig. 4 is the LED constant current driving circuit figure of many outputs of the utility model embodiment three;

Fig. 5 is the LED constant current driving circuit figure of many outputs of the utility model embodiment four;

Fig. 6 is the LED constant current driving circuit figure of many outputs of the utility model embodiment five;

Fig. 7 is the LED constant current driving circuit figure of many outputs of the utility model embodiment six;

Fig. 8 is the LED constant current driving circuit figure of many outputs of the utility model embodiment seven;

Fig. 9 is the LED constant current driving circuit figure of many outputs of the utility model embodiment eight;

Figure 10 is the LED constant current driving circuit figure of many outputs of the utility model embodiment nine;

Figure 11 is the LED constant current driving circuit figure of many outputs of the utility model embodiment ten;

Figure 12 is the LED constant current driving circuit figure of many outputs of the utility model embodiment 11;

Figure 13 is the LED constant current driving circuit figure of many outputs of the utility model embodiment 12;

Figure 14 is the LED constant current driving circuit figure of many outputs of the utility model embodiment 13;

Figure 15 is the LED constant current driving circuit figure of many outputs of the utility model embodiment 14;

Figure 16 is the LED constant current driving circuit figure of many outputs of the utility model embodiment 15.

Embodiment

Below in conjunction with the accompanying drawing among the utility model embodiment, the technical scheme among the utility model embodiment is clearly and completely described, obviously, described embodiment only is the utility model part embodiment, rather than whole embodiment.Based on the embodiment in the utility model, those of ordinary skills are not making the every other embodiment that is obtained under the creative work prerequisite, all belong to the scope of the utility model protection.

For above-mentioned purpose of the present utility model, feature and advantage can be become apparent more, the utility model is described in further detail below in conjunction with the drawings and specific embodiments.

In the LED constant current driving circuit of the described many outputs of the utility model embodiment, with the sampled signal of the current sampling signal of at least one paths of LEDs load branch or total load current as the reference signal, with the current sampling signal of described reference signal and the load branch that is conditioned input signal as the current regulation control module, utilize the size of the impedance of the load branch that the output signal control of described current regulation control module is conditioned, thus the size of current of regulating this road load branch.

With reference to Fig. 2, be the LED constant current driving circuit figure of many outputs of the utility model embodiment one.In the embodiment one described circuit, as the reference signal, regulate the electric current of other all or part of load branch with the current sampling signal of one road load branch.

Load branch as a reference is referred to as reference arm, and the load branch of being regulated by reference arm is the adjusting branch road.

As shown in Figure 2, the input power supply of this drive circuit is a constant-current source 10, comprises the two paths of LED load branch.As the reference branch road, the electric current of regulating second load branch is that example describes to circuit shown in Figure 2 with first load branch.Described second load branch is the adjusting branch road.

First load branch as the reference branch road comprises: LED load A1 and current sample module 11; Described LED load A1 and 11 series connections of current sample module are at the output of described constant-current source 10.

Comprise as second load branch of regulating branch road: LED load A2 and current regulating module 12; Described LED load A2 and current regulating module 12 series connections are at the output of described constant-current source 10.

Described LED load A1 and A2 all can comprise the led light source of one or more series connection.

For described second load branch is provided with a current regulation control module 13, described current regulation control module 13 is connected between described first load branch and second load branch; Concrete, first signal input part of described current regulation control module 13 connects described first load branch, described second load branch of secondary signal input termination of described current regulation control module 13, the current regulating module 12 of described second load branch of output termination of described current regulation control module 13.

Described current regulation control module 13, the current sampling signal of current sample module 11 that is used to receive first load branch as first signal and the current sampling signal of current regulating module 12 that receives second load branch as secondary signal, control the impedance of the current regulating module 12 of second load branch, regulate the electric current of second load branch.

Need to prove that described first signal and described secondary signal have the common reference end, described common reference end is the negative output terminal of constant-current source 10.

Concrete, described current sample module 11 can be specially a resistance, shown in first resistance R 1 among Fig. 2; Described first resistance R 1 be connected between constant-current source 10 and the ground after LED load 1 is connected.

Described current regulating module 12 can be specially one and adjust pipe and a resistance, and described adjustment pipe is connected with described resistance, as adjusting among Fig. 2 shown in the pipe S1 and second resistance R 2; The described adjustment pipe S1 and second resistance R 2 and the output that is connected on constant-current source 10 after LED load 2 is connected successively; The control end of described adjustment pipe S1 is the control end of described current regulating module 12, connects the output of described current regulation control module 13.

The impedance magnitude that described current regulation control module 13 is passed through the described adjustment pipe S1 of control realizes the adjusting to size of current on second load branch.Need to prove that the ratio k of the electric current of two-way load branch is by the ratio decision of described first resistance R 1 and second resistance R 2.

In the LED constant current driving circuit of the utility model embodiment one described many outputs, with the current sampling signal of a paths of LEDs load branch as the reference signal, with the current sampling signal of described reference signal and the LED load branch that is conditioned input signal as described current regulation control module; The size of the impedance of the current regulating module of the described LED load branch that is conditioned of output signal control of described current regulation control module, thereby the size of current of regulating this paths of LEDs load branch.

Two paths of LED load branch in the described circuit of the utility model embodiment can be the led light source of two kinds of different colours.Suppose, LED load 1 is a White LED light source, LED load 2 is the red LED light source, with the current sampling signal of the described White LED light source reference signal as the restrictor ring of red LED light source, makes the electric current of red LED light source and the electric current of White LED light source keep fixing ratio.Because the proportion relation of the electric current of red LED light source and White LED light source can determine the colour temperature of whole LED circuit output and the state of color rendering index (CRI) CRI.Therefore,, make the electric current of red LED light source and the electric current of White LED light source keep fixing ratio, can make the CRI of White LED light source on the low side, mix the light source that suitable red LED light source can be realized low colour temperature, high CRI again by the utility model embodiment.

The light source that illumination is used for major part, the power of white light LEDs is much larger than the LED (as the red LED light source) of other color, voltage with single channel or multichannel white light LEDs in the light source design is designed to the highest, white light LEDs is as the reference branch road, do not add the electric current regulating circuit, the constant-current source output voltage directly is added on the white light LEDs, the driving efficient height of white light LEDs, because it is great that white light LEDs accounts for the power ratio of light source integral body, so the driving efficient height of light source integral body.

With reference to Fig. 3, be the LED constant current driving circuit figure of many outputs of the utility model embodiment two.Fig. 3 is a kind of embodiment of current regulation control module shown in Figure 2.Described current regulation control module 13 comprises: the first operational amplifier IC1, the 4th resistance R 4, first capacitor C 1.

Wherein, the in-phase input end of the described first operational amplifier IC1 receives described first signal as first signal input part of described current regulation control module 13; The inverting input of the described first operational amplifier IC1 receives described secondary signal as the secondary signal input of described current regulation control module 13; The output of the described first operational amplifier IC1 is as the output of described current regulation control module 13.

Described the 4th resistance R 4 and first capacitor C, 1 series connection back constitute compensating network, are connected between the inverting input and output of described operational amplifier IC1.

Wherein, the current sampling signal of described first load branch (first signal is the voltage on first resistance R 1) is input to the in-phase input end of the described first operational amplifier IC1; The current sampling signal of described second load branch (secondary signal is the voltage on second resistance R 2) is input to the inverting input of the described first operational amplifier IC1; The described first operational amplifier IC1 with the current sampling signal of the current sampling signal of described first load branch and described second load branch relatively after, output drive signal is to the control end of described adjustment pipe S1, control the impedance magnitude of described adjustment pipe S1, and then regulate electric current on second load branch.After circuit reaches stable state, make that the ratio of electric current I o2 and the electric current I o1 of first load branch of described second load branch is predefined ratio k; Wherein, described ratio k is by the ratio decision of described first resistance R 1 and second resistance R 2.

Be: Io2/Io1=R1/R2=k.

Certainly, in actual applications, described compensating network can be not limited to way of realization shown in Figure 3, can be any loop compensation network, and following examples together.This part is the known technology of this area, does not repeat them here.

With reference to Fig. 4, be the LED constant current driving circuit figure of many outputs of the utility model embodiment three.Fig. 4 is the another kind of embodiment of current regulation control module shown in Figure 2.

Described current regulation control module 13 comprises: the first operational amplifier IC1, the 4th resistance R 4, first capacitor C, 1, the five adjustable resistance R5.

Wherein, the end of described the 5th adjustable resistance R5 is as first signal input part of described current regulation control module 13, another termination common reference end of described the 5th adjustable resistance R5;

The in-phase input end of the described first operational amplifier IC1 connects the sliding end of described the 5th adjustable resistance R5; The inverting input of the described first operational amplifier IC1 receives described secondary signal as the secondary signal input of described current regulation control module 13; The output of the described first operational amplifier IC1 is as the output of described current regulation control module 13.

Described the 4th resistance R 4 and first capacitor C, 1 series connection back constitute compensating network, are connected between the inverting input and output of the described first operational amplifier IC1.

The utility model embodiment three described circuit are identical with embodiment two to the Principles of Regulation of the electric current of second load branch.The ratio that is electric current I o2 and the electric current I o1 of first load branch of described second load branch no longer is fixing predefined ratio k (ratio of first resistance R 1 and second resistance R 2), but a variable value.Be, can be according to actual needs, by regulating the sliding end of described the 5th adjustable resistance R5, regulate the ratio of the electric current I o1 of the electric current I o2 of described second load branch and first load branch.

Need to prove that described the 5th adjustable resistance R5 can pass through manual adjustments.

With reference to Fig. 5, be the LED constant current driving circuit figure of many outputs of the utility model embodiment four.Fig. 5 is the third embodiment of current regulation control module shown in Figure 2.

Described current regulation control module 13 comprises: the first operational amplifier IC1, the 4th resistance R 4, first capacitor C, 1, the six resistance R 6, filter unit 130, the first metal-oxide-semiconductor S2.

Wherein, an end of described the 6th resistance R 6 is as first signal input part of described current regulation control module 13, the drain electrode of the described first metal-oxide-semiconductor S2 of another termination of described the 6th resistance R 6;

The source electrode of the described first metal-oxide-semiconductor S2 connects the common reference end, and the gate pole of the described first metal-oxide-semiconductor S2 meets control signal V1;

The input of described filter unit 130 connects drain electrode and the source electrode of the described first metal-oxide-semiconductor S2 respectively, the in-phase input end of an output termination first operational amplifier IC1 of described filter unit 130, another output termination common reference end of described filter unit 130;

The inverting input of the described first operational amplifier IC1 receives described secondary signal as the secondary signal input of described current regulation control module 13; The output of the described first operational amplifier IC1 is as the output of described current regulation control module 13.

The utility model embodiment four described circuit are identical with embodiment two to the Principles of Regulation of the electric current of second load branch.The ratio that is electric current I o2 and the electric current I o1 of first load branch of described second load branch no longer is fixing predefined ratio k (ratio of first resistance R 1 and second resistance R 2), but a variable value.The first metal-oxide-semiconductor S2 is operated on off state described in Fig. 5, by regulating the conducting duty ratio of the described first metal-oxide-semiconductor S2, the electric current I o1 that can change described first load branch is through the mean value behind the described filter unit 130, thereby the ratio of electric current I o1 of realizing the electric current I o2 of described second load branch and first load branch is adjustable.

Need to prove that the gate pole control signal V1 of the described first metal-oxide-semiconductor S2 can be the control signal of analog circuit or digital circuit output.Wherein, if be digital circuit, described digital circuit can be accepted user interface control.

Three kinds of embodiments of described current regulation control module have more than been provided.Certainly, the realization of described current regulation control module is not limited to above-mentioned three kinds of modes.In other embodiment of the utility model, described current regulation control module can also realize by other modes.

With reference to Fig. 6, be the LED constant current driving circuit figure of many outputs of the utility model embodiment five.Embodiment illustrated in fig. 6 five and embodiment illustrated in fig. 2 one difference is: be in series with switching tube S3 on the output bus of described constant-current source 10.

Described switching tube S3 is operated in the copped wave state, makes that the electric current of constant-current source 10 outputs is a dc pulse current.By changing the copped wave duty ratio of described switching tube S3, can change the size of constant-current source 10 output current mean values, thereby realize the variation of the brightness of LED load in each load branch.

Circuit shown in Figure 6 can realize that current sampling signal with one road load branch as the reference signal, regulates the electric current of other road load branch.Simultaneously, the module of current regulation control shown in Fig. 6 13 can adopt foregoing any one embodiment of the utility model embodiment to realize.

Previous embodiment all is to be that example describes with the two-way load branch.When load branch was multichannel, current sampling signal that can be by any one road load branch was regulated the electric current of other all or part of load branch as all same reference signals of regulating branch roads.

With reference to Fig. 7, be the LED constant current driving circuit figure of many outputs of the utility model embodiment six.Embodiment illustrated in fig. 7 five and embodiment illustrated in fig. 2 one difference is: described circuit comprises 3 road load branch.Regulate the electric current of other 2 road load branch as the same reference signal of all adjusting branch roads with first load branch.

As shown in Figure 7, for as with reference to first load branch of the branch road current sample module 11 of connecting; Described current sample module 11 can be a resistance.

Be connect respectively as second load branch of regulating branch road and the 3rd load branch a current regulating module 121 and 122.Wherein, described

current regulating module

121 and 122 can be an adjustment pipe and a resistance; Described resistance and the series connection of described adjustment pipe; Described resistance be used to the to sample electric current of this adjusting branch road.

Be respectively described second load branch and the 3rd load branch one current regulation control module is set respectively.Concrete, circuit shown in Figure 7 comprises: the first current regulation control module 131 and the second current regulation control module 132.

The described first current regulation control module 131 is connected between described first load branch and second load branch; First signal input part of the described first current regulation control module 131 connects first load branch, secondary signal input termination second load branch of the described first current regulation control module 131, the current regulating module 121 of output termination second load branch of the described first current regulation control module 131.The described first current regulation control module 131, the current sampling signal of current sample module that is used to receive first load branch is as first signal, with the current sampling signal of the current regulating module that receives second load branch as secondary signal, control the impedance of the current regulating module 121 of second load branch, regulate the electric current of second load branch.

The described second current regulation control module 132 is connected between described first load branch and the 3rd load branch; First signal input part of the described second current regulation control module 132 connects first load branch, secondary signal input termination the 3rd load branch of the described second current regulation control module 132, the current regulating module 122 of output termination the 3rd load branch of the described second current regulation control module 132.The described second current regulation control module 132, the current sampling signal of current sample module that is used to receive first load branch is as first signal, with the current sampling signal of the current regulating module that receives the 3rd load branch as secondary signal, control the impedance of the current regulating module 122 of the 3rd load branch, regulate the electric current of the 3rd load branch.

Each described current regulation control module can adopt foregoing any one embodiment of the utility model embodiment to realize.

When circuit comprises many load branch, can regulate the electric current of other part or all of load branch as a reference with the electric current of any load branch wherein.

The load branch that only is required to be as a reference is provided with a current sample module; The load branch that is conditioned for needs is provided with a current regulating module and current regulation control module respectively.Wherein, described current sample module can be a resistance; Described current regulating module can be an adjustment pipe and a resistance.

Described current regulation control module is corresponding one by one with the load branch that need be conditioned; In other words, what current regulation control modules the load branch that has how many roads to be conditioned just needs.

Each described current regulation control module be connected to load branch as a reference and the adjusting branch road that is attached thereto between, be used for regulating the electric current of the adjusting branch road that is attached thereto with the current sampling signal of as a reference load branch.Described current regulation control module can adopt foregoing any one embodiment of the utility model embodiment to realize.

Previous embodiment all be the current sampling signal of one road load branch as the reference signal, regulate the electric current of other each road load branch.In actual applications, can also regulate the electric current of other load branch with the current signal of multichannel loading branch road as the reference signal.The mean value of current sampling signal that can be by the multichannel loading branch road is regulated the electric current of other all or part of load branch as all same reference signals of regulating branch roads; Perhaps, the current sampling signal that can pass through the multichannel loading branch road is regulated the electric current of other all or part of load branch respectively respectively as a plurality of reference signals; Perhaps aforementioned dual mode is used in combination.

With reference to Fig. 8, be the LED constant current driving circuit figure of many outputs of the utility model embodiment seven.Circuit shown in Figure 8 is that example describes with three tunnel loads.As the reference signal, regulate the electric current of the 3rd load branch with the mean value of the current sampling signal of first load branch and second load branch.Be, described first load branch and second load branch are reference arm, and described the 3rd load branch is for regulating branch road.

Be described first load branch and second load branch current sample module 11 of connecting respectively.Described current sample module can be a resistance.

Be described the 3rd load branch current regulating module 12 of connecting.Described current regulating module 12 can be an adjustment pipe and a resistance.

For described the 3rd load branch is provided with a current regulation control module 13, first signal input part of described current regulation control module 13 connects described first load branch and second load branch, secondary signal input termination the 3rd load branch of described current regulation control module 13, the current regulating module 12 of the adjusting branch road that the output termination of described current regulation control module 13 is attached thereto.

Described current regulation control module 13, be used to receive the current sampling signal of current sample module of first load branch and second load branch the current sampling signal of current sample module as first signal, with the current sampling signal of the current regulating module that receives the 3rd load branch as secondary signal, control the impedance of the current regulating module 12 of the 3rd load branch, regulate the electric current of the 3rd load branch.

When reference arm is two-way, the first input end of described current regulation control module 13 need be linked to each other with each reference arm by a resistance respectively.Concrete, as shown in Figure 8, the first input end of described current regulation control module 13 (being the normal phase input end of the described first operational amplifier IC1 among Fig. 8) links to each other with first load branch by a resistance R 21; The first input end of described current regulation control module 13 links to each other with second load branch by a resistance R 22.

Wherein, described current regulation control module 13 can adopt foregoing any one embodiment of the utility model embodiment to realize.

Preferably, in the circuit, can also increase by a current-sharing unit for each load branch as a reference respectively shown in the embodiment seven, as shown in Figure 8, described current-sharing units in series is connected in each reference arm, is used to strengthen the current-sharing effect of described many output led circuits.

Circuit shown in Figure 8 is that example describes with three tunnel loads.Wherein, as the reference signal, regulate the electric current of Third Road load branch with the mean value of the electric current of two-way load branch.

With reference to Fig. 9, be the LED constant current driving circuit figure of many outputs of the utility model embodiment eight.The difference of circuit shown in Figure 9 and circuit shown in Figure 8 is: comprise four road load branch.As the reference signal, regulate the electric current of other two-way load branch with the mean value of the electric current of two-way load branch wherein.

Concrete, as the reference branch road, then be described first load branch and second load branch current sample module of connecting respectively with first load branch and second load branch.

The 3rd load branch and the 4th load branch be for regulating branch road, is described the 3rd load branch and the 4th load branch current regulating module of connecting respectively.

Be respectively the 3rd load branch and the 4th load branch one current regulation control module is set.As shown in Figure 9, comprise the first current regulation control module 131 and the second current regulation control module 132 respectively.

Need to prove that the first input end of the first current regulation control module 131 links to each other with first load branch, links to each other with second load branch by a resistance R 22 by a resistance R 21.

Equally, the first input end of the second current regulation control module 131 links to each other with first load branch, links to each other with second load branch by a resistance R 22 by a resistance R 21.

The specific implementation form of the described first current regulation control module and second current regulating module is identical with embodiment seven, no longer sets forth at this.

Preferably, in the circuit, can also increase by a current-sharing unit respectively shown in the embodiment eight, as shown in Figure 9, strengthen the current-sharing effect of described many output led circuits for each load branch as a reference.

With reference to Figure 10, be the LED constant current driving circuit figure of many outputs of the utility model embodiment nine.The difference of circuit shown in Figure 10 and circuit shown in Figure 9 is: as the reference signal, regulate the electric current of remaining one road load branch with the mean value of the electric current of two-way load branch; As the reference signal, regulate the electric current of the load branch on remaining another road with the electric current of one road load branch wherein.

The connected mode of its circuit is similar to previous embodiment with principle, no longer sets forth at this.

In the utility model previous embodiment, all be current sampling signal with a certain road or a few roads load branch as the reference signal, regulate the electric current of other all or part of load branch.In actual applications, can also regulate the electric current of other all or part of load branch with the total current signal of all road load branch as the reference signal.

With reference to Figure 11, be the LED constant current driving circuit figure of many outputs of the utility model embodiment ten.Circuit shown in Figure 11 as the reference signal, is regulated the electric current of one road load branch with the sampled signal of total load current.

As shown in figure 11, circuit shown in comprises the two-way load branch.Wherein, the electric current of first load branch is Io1, and the electric current of second load branch is Io2, and then the total load current Io of this circuit is: Io=Io1+Io2.

Among the embodiment ten, the electric current of regulating first load branch with the sampled signal of the total load current of this circuit is that example describes.Be described first load branch current regulating module 101 of connecting.Described current regulating module 101 is connected with the LED load A1 of described first load branch, and one of described series arm terminates at an output of described constant-current source 10, and the other end connects another output of constant-current source 10 by the total current sample circuit.

Described total current sample circuit (not shown among Figure 11) is connected on an output of described constant-current source 10, is used to export total current sampled signal Io.Described total current sample circuit can be a sampling resistor, current transformer or Hall element etc.

Described current regulating module 101 can be an adjustment pipe and a resistance; Can be as adjusting shown in the pipe S1 and first resistance R 1 among Figure 11.Described resistance R 1 and described adjustment pipe S1 series connection; Described resistance R 1 be used to the to sample electric current of described first load branch.

For described first load branch is provided with a current regulation control module 102.Described current regulation control module 102 is connected between the output and first load branch of described constant-current source 10; First signal input part of described current regulation control module 102 connects described total current sample circuit, secondary signal input termination first load branch of described current regulation control module 102, the current regulating module 101 of described first load branch of output termination of described current regulation control module 102.

Described current regulating module 102, be used to receive the current sampling signal of the current regulating module 101 of the total load current sampled signal of described constant-current source 10 outputs and first load branch, control the impedance of the current regulating module 101 of first load branch, regulate the electric current of first load branch.

Among the embodiment ten, as the reference signal, regulate the electric current of each load branch with the sampled signal of total load current, can be proportional so that be conditioned the electric current and the described total load current of load branch.

With reference to Figure 12, be the LED constant current driving circuit figure of many outputs of the utility model embodiment 11.Circuit shown in Figure 12 as the reference signal, is regulated the electric current of two-way load branch with the current sampling signal of total current.

As shown in figure 12, circuit shown in comprises the two-way load branch.Wherein, the electric current of first load branch is Io1, and the electric current of second load branch is Io2, and then the total current Io of this circuit is: Io=Io1+Io2.

Among the embodiment 11, the electric current of regulating first load branch and second load branch with the sampled signal of the total load current of this circuit is that example describes.Be described first load branch and second load branch current regulating module 101 of connecting respectively.Described current regulating module 101 can be an adjustment pipe and a resistance.

Be respectively described first load branch and second load branch one current regulation control module 102 is set.Each current regulation control module 102 is connected on respectively between the output and each load branch of described constant-current source 10, is used for regulating the electric current of first load branch and second load branch respectively with the total load current of described constant-current source output as a reference.

When circuit comprises N road load branch, can come the electric current of regulating load branch road as a reference with the total load current of this circuit.Wherein, can regulate the electric current of all load branch, also can only regulate the electric current of part load branch with total load current.

Concrete, the load branch that is conditioned for the needs current regulating module of connecting.Wherein, described current regulating module can be an adjustment pipe and a resistance.

For each load branch that need be conditioned is provided with a current regulation control module respectively; Each current regulation control module is connected between the load branch that the output of constant-current source and needs correspondingly are conditioned.

With reference to Figure 13, be the LED constant current driving circuit figure of many outputs of the utility model embodiment 12.Figure 13 is a kind of embodiment of current regulation control module shown in Figure 11.

Described total current sample circuit comprises: the 12 resistance R 12; Voltage on described the 12 resistance R 12 is total current sampled signal Io.

Described current regulation control module comprises: the 3rd operational amplifier IC3, the 11 resistance R 11, second capacitor C 2, four-operational amplifier IC4, the 13 resistance R the 13, the 14 resistance R the 14, the 15 resistance R the 15, the 16 resistance R 16.

Wherein, the inverting input of described four-operational amplifier IC4 connects an end of the 12 resistance R 12 through the 15 resistance R 15, the normal phase input end of described four-operational amplifier IC4 connects the other end of described the 12 resistance R 12, the normal phase input end of described the 3rd operational amplifier IC3 of output termination of described four-operational amplifier IC4 through the 14 resistance R 14.

16 series connections of the 16 resistance R are between the inverting input and output of described four-operational amplifier IC4; 13 series connections of the 13 resistance R are between the reference ground of the normal phase input end of described four-operational amplifier IC4 and described four-operational amplifier IC4.

The inverting input of described the 3rd operational amplifier IC3 connects described first load branch, the control end of the current regulating module of described first load branch of output termination of described the 3rd operational amplifier IC3.

Described the 11 resistance R 11 and second capacitor C, 2 series connection backs constitute compensating network, are connected between the inverting input and output of described the 3rd operational amplifier IC3.

Wherein, described four-operational amplifier IC4, the 13 resistance R the 13, the 14 resistance R the 14, the 15 resistance R the 15, the 16 resistance R 16 are formed differential amplifier circuit, and its output is received the normal phase input end of described the 3rd operational amplifier IC3 as current reference signal.Described four-operational amplifier IC4 with the current signal of described first load branch and described current reference signal relatively after, output drive signal is to the control end of described adjustment pipe S1, control the impedance magnitude of described adjustment pipe S1, and then regulate electric current on first load branch.After circuit reaches stable state, make that the ratio of electric current I o1 and total load current Io of described first load branch is predefined ratio k; Described ratio k is determined jointly by the resistance of the 11 resistance R the 11, the 12 resistance R the 12, the 13 resistance R the 13, the 14 resistance R the 14, the 15 resistance R 15, the 16 resistance R 16.

When satisfying: when R15=R14, R13=R16, the electric current I o1 of first load branch with the ratio of total load current Io is:

k＝Io1/Io＝(R13/R14)*(R12/R1)。

Certainly, in actual applications, described compensating network can be not limited to way of realization shown in Figure 13, can be any loop compensation network.This part is the known technology of this area, does not repeat them here.

With reference to Figure 14, be the LED constant current driving circuit figure of many outputs of the utility model embodiment 13.Figure 14 is the another kind of embodiment of current regulation control module shown in Figure 11.

The difference of current regulating module shown in Figure 14 and Figure 13 is: also comprise the 17 adjustable resistance R17.

Described current regulation control module comprises: the 3rd operational amplifier IC3, the 11 resistance R 11, second capacitor C 2, four-operational amplifier IC4, the 13 resistance R the 13, the 14 resistance R the 14, the 15 resistance R the 15, the 16 resistance R the 16, the 17 adjustable resistance R17.

Wherein, two stiff ends of described the 17 adjustable resistance R17 are connected on described the 12 resistance R 12 two ends respectively.

The inverting input of described four-operational amplifier IC4 connects the adjustable end of described the 17 adjustable resistance R17 through the 15 resistance R 15, the normal phase input end of described four-operational amplifier IC4 connects a stiff end of the 17 resistance, the normal phase input end of described the 3rd operational amplifier IC3 of output termination of described four-operational amplifier IC4 through the 14 resistance R 14.

16 series connections of described the 16 resistance R are between the inverting input and output of described four-operational amplifier IC4; 13 series connections of described the 13 resistance R are between the reference ground of the normal phase input end of described four-operational amplifier IC4 and described four-operational amplifier.

The utility model embodiment 13 described circuit are identical with embodiment 12 to the Principles of Regulation of the electric current of first load branch.The ratio that is electric current I o1 and the total load current Io of described first load branch no longer is fixing predefined ratio k, but a variable value.Be, can by regulating the sliding end of described the 17 adjustable resistance R17, regulate the electric current I o1 of described first load branch and the ratio of total load current Io according to actual needs.

Need to prove that described the 17 adjustable resistance R17 can pass through manual adjustments.

With reference to Figure 15, be the LED constant current driving circuit figure of many outputs of the utility model embodiment 14.Figure 15 is the third embodiment of current regulation control module shown in Figure 11.

Current regulation control module shown in Figure 15 and difference shown in Figure 13 are: also comprise filter unit 130, the second metal-oxide-semiconductor S12, the 18 resistance R 18.

Described current regulation control module comprises: the 3rd operational amplifier IC3, the 11 resistance R 11, second capacitor C 2, four-operational amplifier IC4, the 13 resistance R the 13, the 14 resistance R the 14, the 15 resistance R the 15, the 16 resistance R 16, filter unit, the second metal-oxide-semiconductor S12, the 18 resistance R 18.

Wherein, the hot end of described the 12 resistance R 12 of one end of described the 18 resistance R 18, another termination of described the 18 resistance R 18 connects the drain electrode of the described second metal-oxide-semiconductor S12, the source electrode of the described second metal-oxide-semiconductor S12 connects the cold end of described the 12 resistance R 12, and the gate pole of the described second metal-oxide-semiconductor S12 meets control signal V1.

Two inputs of described filter unit connect the drain-source utmost point and the ground of the described second metal-oxide-semiconductor S12 respectively, an output of described filter unit 130 connects the reversed-phase output of four-operational amplifier IC4 through the 15 resistance R 15, and another output of described filter unit 130 connects the normal phase input end of four-operational amplifier IC4 through the 14 resistance R 14.

The normal phase input end of described the 3rd operational amplifier IC3 of output termination of described four-operational amplifier IC4.

The utility model embodiment 14 described circuit are identical with embodiment 12 to the Principles of Regulation of the electric current of first load branch.The ratio that is electric current I o1 and the total load current Io of described first load branch no longer is fixing predefined ratio k, but a variable value.The S2 of metal-oxide-semiconductor described in Fig. 5 is operated on off state, by regulating the conducting duty ratio of the described second metal-oxide-semiconductor S12, can change described total load current Io through the mean value behind the described filter unit, thereby the ratio of realizing the electric current I o1 of described first load branch and total load current Io is adjustable.

Need to prove that the gate pole control signal V1 of the described second metal-oxide-semiconductor S12 can be the control signal of analog circuit or digital circuit output.Wherein, if be digital circuit, described digital circuit can be accepted user interface control,

With reference to Figure 16, be the LED constant current driving circuit figure of many outputs of the utility model embodiment 15.Embodiment illustrated in fig. 16 15 and embodiment illustrated in fig. 12 11 difference is: be in series with switching tube S11 on the output bus of described constant-current source.

Described switching tube S11 is operated in the copped wave state, makes that the electric current of constant-current source output is a dc pulse current.By changing the copped wave duty ratio of described switching tube S11, can change the size of constant-current source output current mean value, thereby realize the variation of the brightness of LED load in each load branch.

Circuit shown in Figure 16 can realize that also current sampling signal with one road load branch as the reference signal, regulates the electric current of other road load branch.Simultaneously, the module of current regulation control shown in Figure 16 can adopt the foregoing three kinds of embodiments of the utility model embodiment to realize.

More than to the LED constant current driving circuits of a kind of many outputs provided by the utility model, be described in detail, used specific case herein principle of the present utility model and execution mode are set forth, the explanation of above embodiment just is used for helping to understand method of the present utility model and core concept thereof; Simultaneously, for one of ordinary skill in the art, according to thought of the present utility model, part in specific embodiments and applications all can change.In sum, this description should not be construed as restriction of the present utility model.

Claims

1. the LED constant current driving circuit of output more than a kind is characterized in that described circuit comprises: a constant-current source; Described constant-current source has two-way load branch at least;

2. the LED constant current driving circuit of many outputs according to claim 1 is characterized in that described first signal and described secondary signal have the common reference end, and described common reference end is the negative output terminal of constant-current source;

3. the LED constant current driving circuit of many outputs according to claim 1 is characterized in that described first signal and described secondary signal have the common reference end, and described common reference end is the negative output terminal of constant-current source;

4. the LED constant current driving circuit of many outputs according to claim 1 is characterized in that described first signal and described secondary signal have the common reference end, and described common reference end is the negative output terminal of constant-current source;

5. the LED constant current driving circuit of many outputs according to claim 1 is characterized in that described current sample module is a resistance.

6. the LED constant current driving circuit of many outputs according to claim 1 is characterized in that, described current regulating module is that a resistance and one is adjusted pipe; Described resistance and the series connection of described adjustment pipe; Described resistance be used to the to sample electric current of this adjusting branch road.

7. according to the LED constant current driving circuit of each described many outputs of claim 1 to 6, it is characterized in that, be in series with switching tube on the output bus of described constant-current source.

8. according to LED constant current driving circuits of each described many outputs of claim 1 to 6, it is characterized in that, when the first input end of described current regulation control module is connected to few two-way reference arm, for every road reference arm is provided with a current-sharing unit; The LED load series connection of described current-sharing unit and described current sample module, reference arm is between described constant-current source and ground;

9. the LED constant current driving circuit of output more than a kind is characterized in that described circuit comprises: a constant-current source; Described constant-current source has two-way load branch at least; Wherein at least one load branch is for regulating branch road;

Described total current sample circuit output total current sampled signal;

10. the LED constant current driving circuit of many outputs according to claim 9 is characterized in that described total current sample circuit comprises the 12 resistance, and the described the 12 ohmically voltage is the total current sampled signal;

Described current regulation control module comprises:

11. the LED constant current driving circuit of many outputs according to claim 9 is characterized in that described total current sample circuit comprises the 12 resistance, the described the 12 ohmically voltage is the total current sampled signal;

Described current regulation control module comprises:

12. the LED constant current driving circuit of many outputs according to claim 9 is characterized in that described total current sample circuit comprises the 12 resistance, the described the 12 ohmically voltage is the total current sampled signal;

Described current regulation control module comprises:

13. the LED constant current driving circuit of many outputs according to claim 9 is characterized in that, described current regulating module is that a resistance and one is adjusted pipe; Described resistance and the series connection of described adjustment pipe; Described resistance be used to the to sample electric current of this adjusting branch road.

14. the LED constant current driving circuit according to each described many outputs of claim 9 to 13 is characterized in that, is in series with switching tube on the output bus of described constant-current source.