CN206136406U - LED drive arrangement and protection circuit thereof - Google Patents
LED drive arrangement and protection circuit thereof Download PDFInfo
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- CN206136406U CN206136406U CN201621195789.1U CN201621195789U CN206136406U CN 206136406 U CN206136406 U CN 206136406U CN 201621195789 U CN201621195789 U CN 201621195789U CN 206136406 U CN206136406 U CN 206136406U
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B20/00—Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps
- Y02B20/30—Semiconductor lamps, e.g. solid state lamps [SSL] light emitting diodes [LED] or organic LED [OLED]
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Abstract
The utility model discloses a LED drive arrangement and protection circuit thereof. Wherein, this LED drive arrangement's protection circuit includes: LED drive circuit is including output circuit for signal driver LED lamp pearl according to output circuit output, current sampling circuit connects in LED drive circuit's check point for acquire the measuring current of check point, output control circuit links to each other with electric current acquisition circuit, is greater than at measuring current that control output circuit stops output under the condition of first reference current. The utility model provides a because the resistance short circuit in the chip causes chip output heavy current among the prior art, technical problem that the lamp pearl that leads to the chip to correspond burnt out.
Description
Technical field
This utility model is related to LED and shows and circuit field, in particular to a kind of LED drive device and its protection
Circuit.
Background technology
In the prior art, LED display generally drives multigroup LED lamp bead default to reach by LED drive chip
Display effect, if any one the LED lamp bead brightness in LED viewing areas is too high, or causes to extinguish due to burning out, all can shadow
Ring the display effect to LED display.
But often can there are some shorted devices due to a variety of causes in the device in for driving the LED chip of LED lamp bead
Phenomenon, the short circuit of device may cause the electric current for flowing through LED lamp bead excessive, brightness occur so as to cause LED viewing areas
High phenomenon, affects the life-span of lamp bead, if lamp bead long-time can also directly be burnt out with higher Brightness Duty.
For, because the resistive short in chip causes chip output to export high current, causing chip pair in prior art
The problem that the lamp bead answered burns out, not yet proposes at present effective solution.
Utility model content
This utility model embodiment provides a kind of LED drive device and its protection circuit, at least to solve prior art
In due to the resistive short in chip cause chip output export high current, cause the technology that the corresponding lamp bead of chip burns out to be asked
Topic.
According to the one side of this utility model embodiment, there is provided a kind of protection circuit of LED drive device, including：
LED drive circuit, including output circuit, the signal for being exported according to output circuit drives LED；Current sampling circuit, connection
In the test point of LED drive circuit, for obtaining the detection electric current of test point；Output control circuit, with current collection circuit phase
Even, in the case where detection electric current is more than the first reference current, control output circuit stops output.
According to the another aspect of this utility model embodiment, a kind of LED drive device is additionally provided, including it is above-mentioned any one
Plant the protection circuit of LED matrix.
In this utility model embodiment, LED is driven according to the signal that output circuit is exported by LED drive circuit
Pearl, by be connected to LED drive circuit test point current sampling circuit obtain test point detection electric current, by with electric current
The connected output control circuit of Acquisition Circuit determines test point short circuit in the case where detection electric current is more than the first reference current, and
Control output circuit stops output.Such scheme is by the electric current of acquisition testing point and by the electric current of test point and default first
Reference current compares, so that it is determined that whether test point is short-circuit, and it is defeated to stop LED drive circuit in the case of test point short circuit
Go out the output of circuit, so that the LED lamp bead for being connected to output circuit is extinguished, and then solve in prior art due to chip
In resistive short cause chip output to export high current, the technical problem for causing the corresponding lamp bead of chip to burn out reaches
The technique effect of protection lamp bead.
Description of the drawings
Accompanying drawing described herein is used for providing further understanding to of the present utility model, constitutes the part of the application,
Schematic description and description of the present utility model is used to explain this utility model, does not constitute to of the present utility model improper
Limit.In the accompanying drawings：
Fig. 1 is the schematic diagram of the protection circuit of the LED drive device according to this utility model embodiment；
Fig. 2 is a kind of schematic diagram of the LED drive circuit according to the embodiment of the present application；
Fig. 3 is a kind of schematic diagram of the protection circuit of the LED drive device according to the embodiment of the present application；And
Fig. 4 is the sequential chart according to a kind of REXT of the embodiment of the present application when short-circuit.
Specific embodiment
In order that those skilled in the art more fully understand this utility model scheme, below in conjunction with this utility model reality
The accompanying drawing in example is applied, the technical scheme in this utility model embodiment is clearly and completely described, it is clear that described
Embodiment is only the embodiment of this utility model part, rather than the embodiment of whole.Based on the reality in this utility model
Example is applied, the every other embodiment that those of ordinary skill in the art are obtained under the premise of creative work is not made all should
When the scope for belonging to this utility model protection.
It should be noted that specification and claims of the present utility model and the term " first " in above-mentioned accompanying drawing,
" second " etc. is the object for distinguishing similar, without being used to describe specific order or precedence.It should be appreciated that so
The data for using can be exchanged in the appropriate case, so that embodiment of the present utility model described herein can be with except at this
In diagram or describe those beyond order implement.Additionally, term " comprising " and " having " and their any deformation, meaning
Figure is that covering is non-exclusive to be included, and for example, a series of system, product or the equipment for containing units is not necessarily limited to clearly arrange
Those units for going out, but may include other steps clearly do not list or intrinsic for these products or equipment or list
Unit.
Embodiment 1
According to this utility model embodiment, there is provided a kind of embodiment of the protection circuit of LED drive device, Fig. 1 is root
According to the schematic diagram of the protection circuit of the LED drive device of this utility model embodiment, as shown in figure 1, the guarantor of the LED drive device
Protection circuit includes：
LED drive circuit 10, including output circuit, the signal for being exported according to output circuit drives LED lamp bead.
Current sampling circuit 12, is connected to the test point of LED drive circuit, for obtaining the detection electric current of test point.
Specifically, above-mentioned test point can be susceptible to the devices such as short-circuit resistance.
Output control circuit 14, is connected with current collection circuit, in the case where detection electric current is more than the first reference current
Control output circuit stops output.
Specifically, above-mentioned first reference current can be the electric current of test point when LED drive circuit normally runs, and work as detection
When the electric current of point is more than the first reference current, in order to prevent excessively stream from causing the brightness of lamp bead too high, stop output circuit defeated to LED
Go out.
From the foregoing, it will be observed that the application foregoing circuit drives LED by LED drive circuit according to the signal that output circuit is exported
Pearl, by be connected to LED drive circuit test point current sampling circuit obtain test point detection electric current, by with electric current
The connected output control circuit of Acquisition Circuit determines test point short circuit in the case where detection electric current is more than the first reference current, and
Control output circuit stops output.Such scheme is by the electric current of acquisition testing point and by the electric current of test point and default first
Reference current compares, so that it is determined that whether test point is short-circuit, and it is defeated to stop LED drive circuit in the case of test point short circuit
Go out the output of circuit, so that the LED lamp bead for being connected to output circuit is extinguished, and then solve in prior art due to chip
In resistive short cause chip output to export high current, the technical problem for causing the corresponding lamp bead of chip to burn out reaches
The technique effect of protection lamp bead.
Optionally, according to the above embodiments of the present application, above-mentioned output control circuit includes：
Comparison circuit, is connected between current sampling circuit and power supply, for comparing detection electric current and the first reference current,
Wherein, the first reference current is provided by power supply.
First Schmidt trigger, is connected with comparison circuit, for comparative result to be converted into into level signal.
First phase inverter, is connected with Schmidt trigger, for the corresponding level signal of comparative result to be carried out into anti-phase place
Reason.
Optionally, according to the above embodiments of the present application, above-mentioned comparison circuit includes：
First N-channel field effect transistor, the drain electrode of the first N-channel field effect transistor is connected with power supply, the first N-channel field effect transistor
Grid be connected with the drain electrode of the first N-channel field effect transistor, for obtaining the first reference current；
Second N-channel field effect transistor, the grid phase of the grid of the second N-channel field effect transistor and the first N-channel field effect transistor
Even, it is K dimension scale to be constituted with the first N-channel field effect transistor1Current mirror, for obtaining the first reference current；
First P-channel field-effect transistor (PEFT) pipe, the grid of the first P-channel field-effect transistor (PEFT) pipe is connected with test point, and source electrode is connected with power supply,
Drain electrode is connected with the drain electrode of the second N-channel field effect transistor, and the reference voltage for providing with the second N-channel field effect transistor is compared
Compared with.
Optionally, according to the above embodiments of the present application, above-mentioned LED drive circuit includes：
First feedback loop, including the first amplifier and the 3rd N-channel field effect transistor, for making the pressure drop etc. of test point
In reference voltage, wherein, the source electrode of the 3rd N-channel field effect transistor is grounded through first resistor；
Second P-channel field-effect transistor (PEFT) pipe, source electrode is connected with power supply, and grid is connected with drain electrode；
3rd P-channel field-effect transistor (PEFT) pipe, grid is connected through second resistance with the grid of the second P-channel field-effect transistor (PEFT) pipe, source electrode
It is connected with electric current, drain electrode is connected by the 4th P-channel field-effect transistor (PEFT) pipe with the second amplifier；
Output circuit, including the 3rd amplifier, the 3rd amplifier and the second amplifier the second feedback loop of composition, second
It is K that feedback loop is used to make the 4th N-channel field effect transistor and the 5th N-channel field effect transistor constitute dimension scale2Current mirror,
So as to obtain output end current；
First electric capacity, is connected to power supply between the grid of the 3rd P-channel field-effect transistor (PEFT) pipe；
Default control end；Wherein, output end current is equal toREXT is shown first resistor
Resistance, VREXTFor the pressure drop of test point.
Fig. 2 is a kind of schematic diagram of the LED drive circuit according to the embodiment of the present application.In a kind of optional embodiment,
With test point as resistance REXT as an example, VREF1 is used to arrange by the internal reference voltage of LED current, the first amplifier
AMP1 and N3 forms feedback loop so that the current potential VREXT=VREF1 of REXT.P2 (the second P-channel field-effect transistor (PEFT) pipe), P3 (the
Three P-channel field-effect transistor (PEFT) pipes) PMOS current mirrors are constituted, and corresponding transistor size ratio is K1.Resistance R1 and electric capacity C1 is constituted
Low pass filter, for filtering the noise of REXT generations.P4 is PMOS transistor, and for making P2, the drain voltage of P3 is equal, from
And the mismatch current between current mirror P2 and P3 is reduced, Vbias is the gate bias voltage of P4, N4, and N5 is nmos pass transistor, its
In, the grid G ATE current potential of N4 and N5 is equal, because the closed loop that the second amplifier AMP2 and the 3rd amplifier AMP3 is formed is born instead
Feedback loop so that N4, N5 drain D rain voltage is equal, simultaneously because N5, N5 ' corresponding dimension scale is K2, therefore be obtained
Outfan Output Channel electric current IOUT=(VREXT/REXT) the * K1*K2 of output circuit.
In the above-described embodiments, IOUT electric currents are believed also by the default control end that output circuit Output Channel are input into
Number Enable as Enable=0, closes Output Channel internal circuits controlling, i.e. IOUT=0, output circuit stops
Only export；As Enable=1, Output Channel internal circuits, IOUT=(VREXT/REXT) * K1*K2 are opened.In reality
In the circuit application of border, Enable signals and data Data (Data is 0 or 1, and application system can preset Data values) are connected,
That is, working as Date=1, IOUT is not zero；As Data=0, IOUT is zero.
Optionally, according to the above embodiments of the present application, above-mentioned LED drive circuit also includes：
5th P-channel field-effect transistor (PEFT) pipe, grid is connected to the outfan of the first phase inverter, in test point electric current more than the
In the case of one reference current, control the 3rd P-channel field-effect transistor (PEFT) pipe cut-off is less than the feelings of the first reference current in test point electric current
Under condition, control the 3rd P-channel field-effect transistor (PEFT) pipe conducting.
Above-mentioned 5th P-channel field-effect transistor (PEFT) pipe is used to be pulled up in the case where test point electric current is more than the first reference current and starts
Work, ends the 3rd P-channel field-effect transistor (PEFT) pipe, so as to reduce device power consumption.
Fig. 3 is a kind of schematic diagram of the protection circuit of the LED drive device according to the embodiment of the present application, and phase inverter INV2 is defeated
The Reset signals for going out end are electronegative potential, and in the case where the electric current of test point is more than the first reference current, pull-up PMOS P5 are opened
Beginning work, PMOS P3 grid potentials will be pulled to power supply potential (now Switch is off), P3 shut-offs, so as to reach
Having arrived reduces the purpose of device power consumption.
In the above-described embodiments, because protection circuit is detecting always whether REXT resistance is short-circuited.If being short-circuited,
LED lamp bead is also not in of short duration high current, therefore the protection circuit can protect lamp bead not affected by REXT short circuits.
Optionally, according to the above embodiments of the present application, foregoing circuit also includes：
6th N-channel field effect transistor and the 6th P-channel field-effect transistor (PEFT) pipe, the grid and the 6th P ditches of the 6th N-channel field effect transistor
The grid of road field effect transistor is connected to the outfan of the first phase inverter, the drain electrode of the 6th N-channel field effect transistor and the 6th P-channel field
The drain electrode of effect pipe is connected with the second Schmidt trigger, and the source electrode of P-channel field-effect transistor (PEFT) pipe is connected to power supply, the 6th N-channel field
The source electrode of effect pipe is grounded by the second reference current source, in the case of being less than the first reference current in test point electric current,
Electronegative potential is exported to shown second Schmidt trigger, in the case where test point electric current is more than the first reference current, to shown
Second Schmidt trigger exports high potential；
Second Schmidt trigger, the drain electrode phase of the input of the second Schmidt trigger and the 6th N-channel field effect transistor
Even, the outfan of the second Schmidt trigger is connected with the second phase inverter；
Second electric capacity, is connected between the input of the second Schmidt trigger and ground, in the 6th N-channel field effect
Pipe is released in the case of turning on according to the second reference current；
Second phase inverter, input is connected with the second Schmidt trigger, and outfan is connected with gate, for second
The result of Schmidt trigger output carries out anti-phase process；
Wherein, gate includes NAND gate and is connected to the 3rd phase inverter of the NAND gate outfan, gate it is defeated
Enter outfan and default control end of the end for the second phase inverter.
In a kind of optional embodiment, as shown in figure 3, still so that test point is for resistance REXT as an example, the second Schmidt touches
Send out device Schmitt2 inputs Vcap and connect electric capacity C2, the 6th N-channel field effect transistor N6 source class and ground series connection reference current over the ground
Source IREF2, enables the second electric capacity to release with the second reference current.During normal work, because the electric current for flowing through sampling P1 is less than
The grid Vc for flowing through the electric current of N2, N6 and P6 is electronegative potential, and the second Schmidt trigger Schmitt2 inputs Vcap is high electricity
Position；When noise occurs, if flowing through sampling P1 electric currents more than the electric current for flowing through N2, N6 and P6 grids become high potential, now N6
Conducting, P6 shut-offs, electric capacity C2 electric charges are released by reference current IREF2, when Vcap is less than Schmitt2 turnover voltages,
Reset just changes to electronegative potential by high potential, and whole device just enters real REXT resistive short guard modes, the guard mode
As control output circuit stops the state of output.
The concrete sequential of above-described embodiment as shown in figure 4, with reference to shown in Fig. 3 and Fig. 4, when normally running, the first phase inverter
The outfan Vc of INV1 is electronegative potential, and Vcap is high potential, when noise occurs, flows through N2's if flowing through sampling P1 electric currents and being more than
Electric current, Vc is high potential, and N6 conductings, P6 shut-offs, electric capacity C2 electric charges are released by reference current IREF2, electric capacity C2 voltage Vcap
From power supply be released to Schmitt2 turnover voltages used by the time be time for shielding noise misoperation, equal to for determining that REXT is electric
The minimum time of resistance short circuit, i.e., do not overturn yet, it is determined that REXT resistive shorts more than time Schmitt2.If noise temporal is little
In REXT resistive short minimum times, before Reset signals are turned to electronegative potential from high potential, Vsample can become low electricity
Position, Vcap quickly becomes high potential, and Reset will be always maintained at high potential, not have any impact to device normal work.In Fig. 4,
Vsample rising edges are the minimum time for determining REXT resistive shorts to the time of Reset trailing edges, by being used to determine REXT
The minimum time of resistive short, can effectively evade because extraordinary noise or emergency case cause defencive function false triggering.
Below, with reference to Fig. 4 to above-described embodiment in the implementation of circuit of noise that prevents be described further, tie
The sequential chart shown in Fig. 4 is closed, when the electric current of test point is more than the first reference current, Vsample is high electricity by electronegative potential saltus step
Position, the outfan of the first phase inverter INV1 also by electronegative potential saltus step to high potential, due to the second electric capacity C2's released by Vcap ends, by
High potential drops to electronegative potential, because the decline of Vcap terminal potentials causes because the second electric capacity C2 releases, therefore is one
The process for progressively declining, if the electric current more than the first reference current because noise causes, in a short period of time,
Vsample can be by high potential again saltus step to electronegative potential, and now the current potential at Vcap ends does not also drop to the second schmidt trigger
The turnover voltage of device Schmitt2, therefore the second Schmidt trigger Schmitt2 will not overturn in these cases, output electricity
Normally run on road；If the electric current due to resistive short during the first reference current more than being caused, under the Vcap terminal potentials
When being down to the turnover voltage of the second Schmidt trigger Schmitt2 turnover voltages, Reset by high potential saltus step to electronegative potential, from
And causing output circuit to stop output, LED lamp bead is extinguished.
Optionally, according to the above embodiments of the present application, foregoing circuit also includes：
Switch, is connected between the grid of the second P-channel field-effect transistor (PEFT) pipe and second resistance, for anti-phase according to described first
The control closure or openness of device, specifically, disconnect in the case where the first phase inverter is high potential by electronegative potential saltus step.
Due to there is the minimum time for determining REXT resistive shorts, if test point is short-circuit, in the Minimal Protective time
Interior protection circuit does not also work, then LED lamp bead can be caused the of short duration high current i.e. too high phenomenon of brightness occur, above-mentioned in order to evade
Due to being used for determining that the brightness of the LED lamp bead caused by the minimum time of REXT resistive shorts is too high, above-mentioned protection circuit disconnects
The switch being connected between the grid of the second P-channel field-effect transistor (PEFT) pipe and second resistance.
In a kind of optional embodiment, with reference to shown in Fig. 3, still with test point as REXT as an example, in this example,
The switch is Switch, and Switch is controlled by the outfan control Vc of the first phase inverter, Vc=0's (i.e. Vc is in electronegative potential)
In the case of, Switch closures；In the case of Vc=H (i.e. Vc is in high potential), Switch disconnects, that is to say, that once
There is short circuit in REXT resistance, and Vsample becomes high potential by electronegative potential, and phase inverter INV1 output current potential Vc are uprised by low, will
So that Switch disconnects so that the 5th P-channel field-effect transistor (PEFT) pipe P3 grid potentials will be kept, LED display still according to
Normal condition shows that lamp bead is not in the too high phenomenon of brightness, when the short circuit event of REXT exceedes for determining that REXT resistance is short
During the minimum time on road, Reset signal step-downs, device enters real guard mode, and P3 grids are pulled to power supply, and data are clear
Zero, LED lamp bead shut-off.As REXT resistance recovers to normal condition from short circuit, then Vsample, Vc are by high potential saltus step to low
Current potential, Switch closures, now P5 grid potentials be reduced to and the electricity such as P2 grids from power supply potential through low pass filter R1, C1
Position, LED lamp bead is also not in the too high phenomenon of high current i.e. brightness, wherein, R2 and C3 can be used to shield high-frequency noise.
A kind of optional embodiment of the application as described in Figure 3 is described further below.
As shown in Figure 3 circuit, in order to evade LED lamp bead is burnt out, or high current affects the LED lamp bead life-span, by P1 grids and
P3 grids connect, and such grid is poor with source voltage equal, once electric on device, P1 will always sample and flow through the electric current of P3, together
When flow through the electric current of P1 and be compared with reference current IREF1*K (K be NMOS N1, the current mirror ratio of N1) always.Work as REXT
When connecting normal, P1 electric currents are flow through less than the electric current for flowing through N2, the input Vsample of Schmidt trigger Schmitt1 is low
Current potential, phase inverter INV2 output Reset signals are high potential, and pull-up P5 is closed, while on data also without any impact.When
When short circuit occurs in REXT, there is high current in NMOS N3 and PMOS P3 branch roads, while P1 will also sample high current, at this moment flow through
More than N2 electric currents are flow through, the input Vsample of Schmidt trigger Schmitt1 becomes high potential, phase inverter to the electric current of P1
INV2 output Reset signals are electronegative potential, and pull-up PMOS P5 start working, and PMOS P3 grid potentials will be pulled to power supply (this
When Switch be off), P3 shut-off, reduce device power consumption.Two inputs of NAND gate Nand2 be respectively Reset and
Data signal, due to Reset=0 so that Data cannot reach Output Channel modules, and phase inverter INV3 be output as it is low
Current potential, i.e. Output Channel circuit modules Enable=0, IOUT=0；The corresponding LED lamp bead region of light-emitting diode display will not
There is the phenomenon that brightness is too high or lamp bead burns out.
Embodiment 2
According to this utility model embodiment, a kind of LED drive device is additionally provided, it is characterised in that including in embodiment 1
Any one LED drive device protection circuit.
Specifically, above-mentioned LED drive device can be that a kind of LED drive chip, or a kind of LED drive module.
The protection circuit of the LED drive device included by LED drive device that above-described embodiment is provided drives electricity by LED
Road drives LED lamp bead according to the signal that output circuit is exported, the current sample electricity of the test point by being connected to LED drive circuit
Road obtains the detection electric current of test point, and first is more than in detection electric current by the output control circuit being connected with current collection circuit
Test point short circuit is determined in the case of reference current, and control output circuit stops output.Such scheme passes through acquisition testing point
Electric current and the electric current of test point is compared with default first reference current, so that it is determined that whether test point short-circuit, and
Stop the output of LED drive circuit output circuit in the case of test point short circuit, so that being connected to the LED of output circuit
Pearl is extinguished, and then is solved in prior art because the resistive short in chip causes chip output to export high current, is caused
The technical problem that the corresponding lamp bead of chip burns out, has reached the technique effect of protection lamp bead.
Above-mentioned this utility model embodiment sequence number is for illustration only, does not represent the quality of embodiment.
In above-described embodiment of the present utility model, the description to each embodiment all emphasizes particularly on different fields, in certain embodiment
Without the part described in detail, the associated description of other embodiment is may refer to.
The above is only preferred implementation of the present utility model, it is noted that for the common skill of the art
For art personnel, on the premise of without departing from this utility model principle, some improvements and modifications can also be made, these improve and
Retouching also should be regarded as protection domain of the present utility model.
Claims (10)
1. a kind of protection circuit of LED drive device, it is characterised in that include：
LED drive circuit, including output circuit, the signal for being exported according to the output circuit drives LED lamp bead；
Current sampling circuit, is connected to the test point of the LED drive circuit, for obtaining the detection electric current of the test point；
Output control circuit, is connected with the current collection circuit, and in the detection electric current situation of the first reference current is more than
It is lower to control the output circuit stopping output.
2. circuit according to claim 1, it is characterised in that the output control circuit includes：
Comparison circuit, is connected between the current sampling circuit and power supply, for relatively more described detection electric current and the first benchmark
Electric current, wherein, first reference current is provided by the power supply；
First Schmidt trigger, is connected with the comparison circuit, for comparative result to be converted into into level signal；
First phase inverter, is connected with the Schmidt trigger, for the corresponding level signal of the comparative result to be carried out instead
Phase processor.
3. circuit according to claim 2, it is characterised in that the comparison circuit includes：
First N-channel field effect transistor, the drain electrode of the first N-channel field effect transistor is connected with the power supply, first N-channel
The grid of field effect transistor is connected with the drain electrode of the first N-channel field effect transistor, for obtaining first reference current；
Second N-channel field effect transistor, the grid of the grid of the second N-channel field effect transistor and the first N-channel field effect transistor
Extremely it is connected, it is K to constitute dimension scale with the first N-channel field effect transistor1Current mirror, for obtaining first benchmark electricity
Stream；
First P-channel field-effect transistor (PEFT) pipe, the grid of the first P-channel field-effect transistor (PEFT) pipe is connected with the test point, source electrode with it is described
Power supply is connected, and drain electrode is connected with the drain electrode of the second N-channel field effect transistor, for carrying with the second N-channel field effect transistor
For the reference voltage be compared.
4. circuit according to claim 3, it is characterised in that the LED drive circuit includes：
First feedback loop, including the first amplifier and the 3rd N-channel field effect transistor, the pressure drop for making test point is equal to base
Quasi- voltage, wherein, the source electrode of the 3rd N-channel field effect transistor is grounded through first resistor；
Second P-channel field-effect transistor (PEFT) pipe, source electrode is connected with power supply, and grid is connected with drain electrode；
3rd P-channel field-effect transistor (PEFT) pipe, the grid is connected through second resistance with the grid of the second P-channel field-effect transistor (PEFT) pipe,
The source electrode is connected with electric current, and the drain electrode is connected by the 4th P-channel field-effect transistor (PEFT) pipe with the second amplifier；
The output circuit, including the 3rd amplifier, the 3rd amplifier constitutes the second negative feedback with second amplifier
Loop, second feedback loop is used to make the 4th N-channel field effect transistor and the 5th N-channel field effect transistor constitute dimension scale
For K2Current mirror, so as to obtain output end current；
First electric capacity, is connected to the power supply between the grid of the 3rd P-channel field-effect transistor (PEFT) pipe；
Default control end；
Wherein, the output end current is equal toThe REXT is the resistance of shown first resistor, institute
State VREXTFor the pressure drop of the test point.
5. circuit according to claim 4, it is characterised in that the LED drive circuit also includes：
5th P-channel field-effect transistor (PEFT) pipe, grid is connected to the outfan of first phase inverter, for big in the test point electric current
In the case of first reference current, the 3rd P-channel field-effect transistor (PEFT) pipe cut-off is controlled, be less than in the test point electric current
In the case of first reference current, the 3rd P-channel field-effect transistor (PEFT) pipe conducting is controlled.
6. circuit according to claim 5, it is characterised in that the circuit also includes：
6th N-channel field effect transistor and the 6th P-channel field-effect transistor (PEFT) pipe, the grid of the 6th N-channel field effect transistor and described
The grid of six P-channel field-effect transistor (PEFT) pipes is connected to the outfan of first phase inverter, the drain electrode of the 6th N-channel field effect transistor
It is connected with the second Schmidt trigger with the drain electrode of the 6th P-channel field-effect transistor (PEFT) pipe, the source electrode of the P-channel field-effect transistor (PEFT) pipe connects
The power supply is connected to, the source electrode of the 6th N-channel field effect transistor is grounded by the second reference current source, in the detection
Point electric current exports electronegative potential, in the inspection less than in the case of first reference current to shown second Schmidt trigger
Measuring point electric current exports high potential more than in the case of first reference current to shown second Schmidt trigger；
Second Schmidt trigger, the input of second Schmidt trigger and the 6th N-channel field effect transistor
Drain electrode be connected, the outfan of second Schmidt trigger is connected with the second phase inverter；
Second electric capacity, is connected between the input of second Schmidt trigger and ground, in the 6th N-channel field
Effect pipe is released in the case of turning on according to the second reference current；
Second phase inverter, input is connected with second Schmidt trigger, and outfan is connected with gate, for right
The result of the second Schmidt trigger output carries out anti-phase process.
7. circuit according to claim 6, it is characterised in that the gate include NAND gate and described in being connected to it is non-
3rd phase inverter of gate output terminal, the input of the gate is the outfan and the default control of second phase inverter
End.
8. circuit according to claim 6, it is characterised in that the circuit also includes：
Switch, is connected between the grid of the second P-channel field-effect transistor (PEFT) pipe and the second resistance, for according to described first
The control closure or openness of phase inverter.
9. circuit according to claim 8, it is characterised in that the switch is used in first phase inverter by electronegative potential
Saltus step is disconnection in the case of high potential.
10. a kind of LED drive device, it is characterised in that including the protection of any one LED drive device in claim 1 to 9
Circuit.
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|---|---|---|---|
| CN201621195789.1U CN206136406U (en) | 2016-10-31 | 2016-10-31 | LED drive arrangement and protection circuit thereof |
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| CN201621195789.1U CN206136406U (en) | 2016-10-31 | 2016-10-31 | LED drive arrangement and protection circuit thereof |
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| CN206136406U true CN206136406U (en) | 2017-04-26 |
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106550508A (en) * | 2016-10-31 | 2017-03-29 | 北京集创北方科技股份有限公司 | LED drive device and control method and its protection circuit and control method |
| CN109859681A (en) * | 2019-03-28 | 2019-06-07 | 北京集创北方科技股份有限公司 | A kind of LED display driver circuit, display, driving method and driving chip |
| CN111083826A (en) * | 2019-12-25 | 2020-04-28 | 深圳市芯飞凌半导体有限公司 | LED drive circuit capable of adjusting brightness and color |
| US10952300B2 (en) | 2018-06-27 | 2021-03-16 | Chipone Technology (Beijing) Co., Ltd. | LED driver and controller thereof, and LED lighting device |
-
2016
- 2016-10-31 CN CN201621195789.1U patent/CN206136406U/en active Active
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106550508A (en) * | 2016-10-31 | 2017-03-29 | 北京集创北方科技股份有限公司 | LED drive device and control method and its protection circuit and control method |
| CN106550508B (en) * | 2016-10-31 | 2019-03-12 | 北京集创北方科技股份有限公司 | LED drive device and control method and its protection circuit and control method |
| US10952300B2 (en) | 2018-06-27 | 2021-03-16 | Chipone Technology (Beijing) Co., Ltd. | LED driver and controller thereof, and LED lighting device |
| CN109859681A (en) * | 2019-03-28 | 2019-06-07 | 北京集创北方科技股份有限公司 | A kind of LED display driver circuit, display, driving method and driving chip |
| CN109859681B (en) * | 2019-03-28 | 2024-06-11 | 北京集创北方科技股份有限公司 | LED display driving circuit, display, driving method and driving chip |
| CN111083826A (en) * | 2019-12-25 | 2020-04-28 | 深圳市芯飞凌半导体有限公司 | LED drive circuit capable of adjusting brightness and color |
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