CN203588109U - Cascade over-temperature protection circuit for integrated LED drive chips - Google Patents
Cascade over-temperature protection circuit for integrated LED drive chips Download PDFInfo
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- CN203588109U CN203588109U CN201320759124.9U CN201320759124U CN203588109U CN 203588109 U CN203588109 U CN 203588109U CN 201320759124 U CN201320759124 U CN 201320759124U CN 203588109 U CN203588109 U CN 203588109U
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Abstract
The utility model discloses a cascade over-temperature protection circuit for integrated LED drive chips. The cascade over-temperature protection circuit comprises an over-temperature compensation circuit and an over-temperature protection circuit. The over-temperature compensation circuit comprises a current mirror circuit, a fifth resistor, a triode, a differential amplifier, a first comparator and a first either-or data selector. The over-temperature protection circuit comprises a second comparator, a third resistor, a fourth resistor and a second either-or data selector. When temperature exceeds the over-temperature compensation threshold value T1, over-current cooling is started, working current of LED lights can be subjected to drop compensation from fixed constant current according to the set slope continuous-line, so that LED beads are prevented from being aged or damaged due to high temperature on the premise of guaranteeing certain brightness. When the temperature raises continuously until exceeding the protection threshold value T2, micro-current protection is started, the beads are guaranteed to have certain voltage drop on the premise of no lighting and no heating of the beads, so that the LED beads and drive-level NMOS (N-channel metal oxide semiconductor FET) tubes are protected simultaneously.
Description
Technical field
The utility model relates to LED domain of control temperature, relates in particular to the step excess temperature compensation holding circuit that is exclusively used in high pressure line style integrated LED driving chip.
Background technology
LED light fixture can send amount of heat at work, if the heat radiation of light fixture is bad or environment is severe, the temperature of LED light fixture can raise very soon, and the higher meeting of temperature makes the light emission rate of LED lower, and the life-span of LED lamp is shorter.So for LED light fixture, temperature control is most important.Tradition LED drive circuit in the course of the work, adopts the detection mode of external temp sensor or thermistor to carry out detected temperatures conventionally, and then carrys out regulating circuit to reduce temperature by the output duty cycle that internal circuit changes LED drive circuit.
Along with the development of LED Driving technique, state-of-the art high pressure line style integrated LED drives chip to have without stroboscopic, little, the peripheral simple feature of area, the frequent and integrated use of LED lamp pearl.Be widely used.This applied environment has proposed new requirement to the temperature controlled circuit arrangement of light fixture and design: (1) temperature-control circuit must be simple, easy of integration.(2) do not need external temperature sensor.(3) temperature-control circuit overheated shutoff simply, in order to avoid the NMOS of high-voltage breakdown driving stage pipe.This becomes the applicant and is devoted to the problem solving.
Summary of the invention
The purpose of this utility model is to be provided for high pressure line style integrated LED and drives the step excess temperature of chip to compensate holding circuit, be simple and easy to integrated, adopted the excess temperature compensation protection mechanism of two-stage, when the stream of temperature drop excessively of one-level, can in the situation that guaranteeing certain brightness, protect the not Yin Gaowen quick aging damage of inner LED lamp pearl; When the miniflow protection of secondary, can in luminous athermic situation, still guarantee that lamp pearl has certain pressure drop hardly on lamp pearl, to protect the NMOS pipe of driving stage.
The technical scheme that realizes above-mentioned purpose is:
A step excess temperature compensation holding circuit that drives chip for integrated LED, described integrated LED drives chip to comprise the first amplifier, NMOS pipe and integrated LED lamp pearl; The drain electrode of described NMOS pipe connects described integrated LED lamp pearl, and source electrode connects the inverting input of described the first amplifier, and grid connects the output terminal of described the first amplifier;
Described step excess temperature compensation holding circuit comprises excess temperature compensating circuit and thermal-shutdown circuit, wherein: excess temperature compensating circuit comprises current mirror circuit, the 5th resistance, triode, differential amplifier, the first comparer and the first alternative data selector; Thermal-shutdown circuit comprises the second comparer, the 3rd resistance, the 4th resistance and the second alternative data selector; Wherein:
The input end of described current mirror circuit receives the electric current I PATA being directly proportional to temperature, current mirror circuit mirror image goes out electric current I PATA and exports at two output terminals, one of them output terminal is by the 5th resistance eutral grounding, the emitter of another output terminal connecting triode, the equal ground connection of the base stage of triode and collector;
Described current mirror circuit is connected the inverting input of described differential amplifier with the end that joins of the 5th resistance;
Described current mirror circuit is connected the in-phase input end of described differential amplifier with the end that joins of triode;
The output terminal of described differential amplifier connects respectively first input end, the inverting input of the first comparer and the inverting input of the second comparer of described the first alternative data selector;
The second input end of described the first alternative data selector and described the first comparer in-phase input end all receive the first reference voltage V R1;
Described the second comparer in-phase input end receives the second reference voltage V R2;
The output terminal of described the first comparer connects the control end of described the first alternative data selector; The output terminal of described the first alternative data selector connects the in-phase input end of described the first amplifier;
The output terminal of described the second comparer connects the control end of described the second alternative data selector;
The first input end of described the second alternative data selector is by described the 3rd resistance eutral grounding, and the second input end is by described the 4th resistance eutral grounding, and output terminal connects the source electrode of described NMOS pipe.
Above-mentioned drives the step excess temperature of chip to compensate holding circuit for integrated LED, and wherein, described current mirror circuit comprises the first metal-oxide-semiconductor, the second metal-oxide-semiconductor and the 3rd metal-oxide-semiconductor, wherein:
The source electrode of described the first metal-oxide-semiconductor connects internal electric source, and drain and gate all connects the input end of described current mirror circuit;
The source electrode of described the second metal-oxide-semiconductor connects internal electric source, and grid connects the input end of described current mirror circuit, and drain electrode connects described the 5th resistance;
The source electrode of described the 3rd metal-oxide-semiconductor connects internal electric source, and grid connects the input end of described current mirror circuit, and drain electrode connects the emitter of described triode.
Above-mentioned drives the step excess temperature of chip to compensate holding circuit for integrated LED, and wherein, described differential amplifier comprises the 6th resistance, the 7th resistance, the 8th resistance and the 3rd amplifier, wherein:
The in-phase input end of described the 3rd amplifier connects the end that joins of described current mirror circuit and triode by described the 8th resistance;
The inverting input of described the 3rd amplifier connects the end that joins of described current mirror circuit and the 5th resistance by described the 6th resistance;
The output terminal of described the 3rd amplifier is as the output terminal of described differential amplifier;
Described the 7th resistance one end connects the inverting input of described the 3rd amplifier, and the other end connects the output terminal of described the 3rd amplifier.
Above-mentioned drives the step excess temperature of chip to compensate holding circuit for integrated LED, and wherein, described step excess temperature compensation holding circuit also comprises reference source circuit, and reference source circuit comprises band gap reference, the second amplifier and variable resistor, wherein:
Described band gap reference is exported described electric current I PATA on the one hand, and output reference voltage signal VBG0 gives the in-phase input end of described the second amplifier on the other hand;
After joining, the inverting input of described the second amplifier and output terminal pass through described variable resistor ground connection;
The described first reference voltage V R1 of end output that joins of described variable resistor and the second amplifier;
Described variable-resistance sliding end is exported described the second reference voltage V R2.
Above-mentioned drives the step excess temperature of chip to compensate holding circuit for integrated LED, and wherein, described the first comparer and the second comparer are the comparer with hysteresis.
Above-mentioned drives the step excess temperature of chip to compensate holding circuit for integrated LED, and wherein, the output terminal of described differential amplifier is exported with slope K
tCwith temperature, raise and the linear excess temperature compensating signal VTC declining; Described the first reference voltage V R1 equates when excess temperature compensates threshold value T1 with excess temperature compensating signal VTC; Described the second reference voltage V R2 and excess temperature compensating signal VTC equate when overheat protector threshold value T2.
Above-mentioned drives the step excess temperature of chip to compensate holding circuit for integrated LED, wherein,
When having served as warm compensating signal VTC and being greater than the first reference voltage V R1, the first alternative data selector is selected its second input end and output terminal connection described in the signal controlling of described the first comparer output; When having served as warm compensating signal VTC and being less than the first reference voltage V R1, the first alternative data selector is selected its first input end and output terminal connection described in the signal controlling of described the first comparer output;
When having served as warm compensating signal VTC and being greater than the second reference voltage V R2, the second alternative data selector is selected its first input end and output terminal connection described in the signal controlling of described the second comparer output; When having served as warm compensating signal VTC and being less than the second reference voltage V R2, the second alternative data selector is selected its second input end and output terminal connection described in the signal controlling of described the second comparer output.
Above-mentioned drives the step excess temperature of chip to compensate holding circuit for integrated LED, wherein,
The value of excess temperature compensating signal VTC is:
V
TC=(1+R6/R5)*V
BE-(R6/R5)*R4*IPTAT
The slope K of excess temperature compensating signal VTC
tCfor compensation slope, as follows:
K
TC=（1+R6/R5）*K
VBE-（R6/R5）*R4*K
IPTAT
Wherein, R6/R5 represents the ratio of the 7th resistance (R6) and the 6th resistance (R5); V
bErepresent emitter and the base voltage across poles of triode (Q1); R4 represents the value of the 5th resistance (R4); IPTAT represents the current value of the positive temperature coefficient (PTC) of reference circuit generation; K
iPTATrepresent the temperature coefficient constant of the electric current I PTAT of positive temperature coefficient (PTC); K
vBErepresent the voltage V of negative temperature coefficient
bEtemperature coefficient constant.
The beneficial effects of the utility model are: the utility model is simple and easy to integrated; adopted the mode of first crossing the rear miniflow protection of temperature drop stream; when the temperature of integrated lamp bulb exceedes excess temperature compensation threshold value T1; start overcurrent cooling; the working current of LED lamp can compensate with the linear decline of slope rate continuity of setting from fixing constant current; to reach the thermal equilibrium of certain point, thereby in the situation that guaranteeing certain brightness, protect the not Yin Gaowen quick aging damage of inner LED lamp pearl.If while causing the lasting rising of temperature of integrated lamp bulb to exceed overheat protector threshold value T2 due to certain fault, start miniflow protection, on lamp pearl, in luminous athermic situation, still guarantee that lamp pearl has certain pressure drop hardly, to protect the NMOS pipe of driving stage.And, no matter which kind of excess temperature, fault get rid of or working environment normal after, system finally all can be got back to normal constant current mode automatically.
Accompanying drawing explanation
Fig. 1 is the circuit diagram of step excess temperature compensation holding circuit of the present utility model;
Fig. 2 is concrete implementation result figure of the present utility model.
Embodiment
Below in conjunction with accompanying drawing, the utility model is described in further detail.
Integrated LED drives chip to comprise the first amplifier 2, NMOS pipe 3 and integrated LED lamp pearl 5; The drain electrode of NMOS pipe 3 connects described integrated LED lamp pearl 5, and source electrode connects the inverting input of the first amplifier 2, and grid connects the output terminal of the first amplifier 2.
Refer to Fig. 1, the step excess temperature compensation holding circuit that drives chip for integrated LED of the present utility model, comprises reference source circuit 101, excess temperature compensating circuit 106 and thermal-shutdown circuit 107; Reference source circuit 101 comprises band gap reference I0, the second amplifier I1 and variable resistor R3; Excess temperature compensating circuit 106 comprises current mirror circuit 103, the 5th resistance R 4, triode Q1, differential amplifier 104, the first comparer I3 and the first alternative data selector S1; Thermal-shutdown circuit 107 comprises the second comparer I4, the 3rd resistance R 1, the 4th resistance R 2 and the second alternative data selector S2, wherein:
The band gap reference I0 electric current I PATA that output is directly proportional to temperature is on the one hand to the input end of current mirror circuit 103, and output reference voltage signal VBG0 gives the in-phase input end of the second amplifier I1 on the other hand; After joining, the inverting input of the second amplifier I1 and output terminal pass through variable resistor R3 ground connection; The end that joins of variable resistor R3 and the second amplifier I1 is connected respectively and exports second input end D1 and the first comparer I3 in-phase input end of the first reference voltage V R1 to the first alternative data selector S1; The sliding end of variable resistor R3 connects and exports the second reference voltage V R2 to the second comparer I4 in-phase input end; The first reference voltage V R1 is corresponding to excess temperature compensation threshold value T1, and the second reference voltage V R2 is corresponding to overheat protector threshold value T2;
The output terminal of differential amplifier 104 connects respectively the inverting input of first input end D0, the first comparer I3 and the inverting input of the second comparer I4 of the first alternative data selector S1;
The output terminal of the first comparer I3 connects the control end S of the first alternative data selector S1; The output terminal COM of the first alternative data selector S1 connects the in-phase input end of the first amplifier 2;
The output terminal of the second comparer I4 connects the control end S of the second alternative data selector S2; In the present embodiment, the first comparer I3 and the second comparer I4 are the comparer with hysteresis;
The first input end D0 of the second alternative data selector S2 is by the 3rd resistance R 1 ground connection, and the second input end D1 is by the 4th resistance R 2 ground connection, and output terminal COM connects the source electrode of NMOS pipe 3.
In the present embodiment, current mirror circuit 103 comprises the first metal-oxide-semiconductor MP1, the second metal-oxide-semiconductor MP2 and the 3rd metal-oxide-semiconductor MP3, wherein:
The source electrode of the first metal-oxide-semiconductor MP1 connects internal electric source (not shown), and drain and gate all connects the input end of current mirror circuit 103;
The source electrode of the second metal-oxide-semiconductor MP2 connects internal electric source, and grid connects the input end of current mirror circuit 103, and drain electrode connects the 5th resistance R 4;
The source electrode of the 3rd metal-oxide-semiconductor MP3 connects internal electric source, and grid connects the input end of current mirror circuit 103, the emitter of drain electrode connecting triode Q1.
In the present embodiment, differential amplifier 104 comprises the 6th resistance R 5, the 7th resistance R 6, the 8th resistance R 7 and the 3rd amplifier I2, wherein:
The in-phase input end of the 3rd amplifier I2 connects the end that joins of current mirror circuit 103 and triode Q1 by the 8th resistance R 7;
The inverting input of the 3rd amplifier I2 connects the end that joins of current mirror circuit 103 and the 5th resistance R 4 by the 6th resistance R 5;
The output terminal of the 3rd amplifier I2 is as the output terminal of differential amplifier 104; The 7th resistance R 6 one end connect the inverting input of the 3rd amplifier I2, and the other end connects the output terminal of the 3rd amplifier I2.
The principle of step excess temperature compensation holding circuit:
Electric current I PATA produces positive temperature coefficient (PTC) voltage VPTAT in the 5th resistance R 4, produces negative temperature coefficient voltage VNTAT on triode Q1, and positive temperature coefficient (PTC) voltage VPTAT and negative temperature coefficient voltage VNTAT obtain with slope K by differential amplifier 104
tCwith temperature, raise and the linear excess temperature compensating signal VTC declining, by the output terminal of differential amplifier 104, exported;
The value of excess temperature compensating signal VTC is:
V
TC=(1+R6/R5)*V
BE-(R6/R5)*R4*IPTAT
The slope K of excess temperature compensating signal VTC
tCfor compensation slope, as follows:
K
TC=（1+R6/R5）*K
VBE-（R6/R5）*R4*K
IPTAT
Wherein, R6/R5 represents the ratio of the 7th resistance R 6 and the 6th resistance R 5; V
bErepresent emitter and the base voltage across poles of triode Q1; R4 represents the value of the 5th resistance R 4; IPTAT represents the current value of the positive temperature coefficient (PTC) of reference circuit generation; K
iPTATrepresent the temperature coefficient constant of the electric current I PTAT of positive temperature coefficient (PTC); K
vBErepresent the voltage V of negative temperature coefficient
bEtemperature coefficient constant.
The first comparer I3 is excess temperature compensating signal VTC and the first reference voltage V R1 relatively, thereby produce excess temperature compensation start signal OT1, by appropriate R6/R5 and two parameters of R4*IPTAT of arranging, excess temperature compensating signal VTC is equated when excess temperature compensates threshold value T1 with the first reference voltage V R1, and the hysteresis of the first comparer I3 can prevent false triggering or switch continuously.When temperature compensates threshold value T1 lower than excess temperature (that is: when excess temperature compensating signal VTC is greater than the first reference voltage V R1), OT1=0, now, the first alternative data selector S1 selects the second input end D1 to connect output terminal COM, exports to the in-phase input end of the first amplifier 2 using the first reference voltage V R1 in normal temperature situation as final reference signal VREF that is:; When temperature exceedes temperature compensation and repays threshold value T1 (; When excess temperature compensating signal VTC is less than the first reference voltage V R1, OT1=1, now, the first alternative data selector S1 selects first input end D0 to connect output terminal COM, that is: using excess temperature compensating signal VTC as final reference signal VREF, export to the in-phase input end of the first amplifier 2, now, adjustable R6/R5 setting compensation slope K
tC, K
tCvalue generally depend on heat dissipation design and the working environment of light fixture, appropriate selection K
tCcan make temperature temporarily be stabilized in a certain equilibrium point; worked in temperature drop stream mode; that is: make the working current of integrated LED lamp pearl 5 can be from the continuous linear decline of constant current of setting to reach the thermal equilibrium of certain point, thereby guaranteeing to protect the not Yin Gaowen quick aging damage of inner LED lamp pearl certain brightness in the situation that.After the temperature rise that external environment condition causes is removed, system is got back to normal constant current mode automatically.
The second comparer I4 is excess temperature compensating signal VTC and the second reference voltage V R2 relatively; thereby produce overheat protector start signal OT2; by the value of the second reference voltage V R2 is appropriately set; excess temperature compensating signal VTC and the second reference voltage V R2 are equated when overheat protector threshold value T2, and the hysteresis of the second comparer I4 can prevent false triggering or switch continuously.When temperature lower than overheat protector threshold value T2(: excess temperature compensating signal VTC is greater than the second reference voltage V R2) time, OT2=0, now, the second alternative data selector S2 selects first input end D0 to connect output terminal COM, the 3rd resistance R 1 is accessed to the source electrode of NMOS pipe 3 that is:; When temperature higher than overheat protector threshold value T2(: excess temperature compensating signal VTC is less than the second reference voltage V R2) time, OT2=1, now, the second alternative data selector S2 selects the second input end D1 to connect output terminal COM, the 4th resistance R 2 is accessed to the source electrode of NMOS pipe 3 that is:; Now, the electric current of integrated LED lamp pearl 5 is protection miniflow: I
oTP=VREF/R2, wherein, VREF is the value of final reference signal VREF, R2 is the resistance of the 4th resistance R 2.Select rightly the value of R2, the Current Limits of integrated LED lamp pearl 5 can be fixed on to very little current value, to guarantee the cooling of lamp pearl; Also guarantee that each LED lamp pearl has suitable pressure drop simultaneously, less to guarantee the drain terminal voltage of high pressure NMOS driving tube 3, to prevent from switching NMOS that rear moment improves, manage 3 drain terminal voltages and punctured.Enter miniflow protected mode, after temperature declines, can first get back to temperature drop stream mode, as normally continued cooling, finally automatically get back to normal constant current mode.
In Fig. 1, HV represents external high pressure power supply.
To sum up, the utility model has adopted the mode of first crossing the rear miniflow protection of temperature drop stream, when crossing temperature drop stream, and can be by adjustment excess temperature compensation threshold value T1 and compensation slope K
tCallow at high temperature continuous firing and not closing of chip, by conjunction with LED light fixture and the main appropriate design compensation slope K of applied environment
tCto reach the thermal equilibrium of certain point, thereby can in the situation that guaranteeing certain brightness, protect inner LED lamp pearl.When miniflow is protected, can be by adjusting overheat protector threshold value T2 and protection miniflow I
oTPallow LED light fixture is accurate to be turn-offed, the value of the voltage-current curve capable of regulating R2 by and LED diode withstand voltage in conjunction with power tube is guaranteed that lamp pearl is accurate turn-off cooling and guarantee that high pressure NMOS driving tube is not smashed by high pressure simultaneously.Concrete implementation result figure of the present utility model as shown in Figure 2.
Above embodiment is only for illustration of the utility model, but not to restriction of the present utility model, person skilled in the relevant technique, in the situation that not departing from spirit and scope of the present utility model, can also make various conversion or modification, therefore all technical schemes that are equal to also should belong to category of the present utility model, should be limited by each claim.
Claims (8)
1. a step excess temperature compensation holding circuit that drives chip for integrated LED, described integrated LED drives chip to comprise that the first amplifier (2), NMOS manage (3) and integrated LED lamp pearl (5); The drain electrode of described NMOS pipe (3) connects described integrated LED lamp pearl (5), and source electrode connects the inverting input of described the first amplifier (2), and grid connects the output terminal of described the first amplifier (2);
It is characterized in that, described step excess temperature compensation holding circuit comprises excess temperature compensating circuit (106) and thermal-shutdown circuit (107), wherein: excess temperature compensating circuit (106) comprises current mirror circuit (103), the 5th resistance (R4), triode (Q1), differential amplifier (104), the first comparer (I3) and the first alternative data selector (S1); Thermal-shutdown circuit (107) comprises the second comparer (I4), the 3rd resistance (R1), the 4th resistance (R2) and the second alternative data selector (S2); Wherein:
The input end of described current mirror circuit (103) receives the electric current I PATA being directly proportional to temperature, current mirror circuit (103) mirror image goes out electric current I PATA and exports at two output terminals, one of them output terminal is by the 5th resistance (R4) ground connection, the emitter of another output terminal connecting triode (Q1), the base stage of triode (Q1) and the equal ground connection of collector;
Described current mirror circuit (103) is connected the inverting input of described differential amplifier (104) with the end that joins of the 5th resistance (R4);
Described current mirror circuit (103) is connected the in-phase input end of described differential amplifier (104) with the end that joins of triode (Q1);
The output terminal of described differential amplifier (104) connects respectively first input end, the inverting input of the first comparer (I3) and the inverting input of the second comparer (I4) of described the first alternative data selector (S1);
The second input end of described the first alternative data selector (S1) and described the first comparer (I3) in-phase input end all receive the first reference voltage V R1;
Described the second comparer (I4) in-phase input end receives the second reference voltage V R2;
The output terminal of described the first comparer (I3) connects the control end of described the first alternative data selector (S1); The output terminal of described the first alternative data selector (S1) connects the in-phase input end of described the first amplifier (2);
The output terminal of described the second comparer (I4) connects the control end of described the second alternative data selector (S2);
The first input end of described the second alternative data selector (S2) is by described the 3rd resistance (R1) ground connection, and the second input end is by described the 4th resistance (R2) ground connection, and output terminal connects the source electrode of described NMOS pipe (3).
2. the step excess temperature compensation holding circuit that drives chip for integrated LED according to claim 1; it is characterized in that; described current mirror circuit (103) comprises the first metal-oxide-semiconductor (MP1), the second metal-oxide-semiconductor (MP2) and the 3rd metal-oxide-semiconductor (MP3), wherein:
The source electrode of described the first metal-oxide-semiconductor (MP1) connects internal electric source, and drain and gate all connects the input end of described current mirror circuit (103);
The source electrode of described the second metal-oxide-semiconductor (MP2) connects internal electric source, and grid connects the input end of described current mirror circuit (103), and drain electrode connects described the 5th resistance (R4);
The source electrode of described the 3rd metal-oxide-semiconductor (MP3) connects internal electric source, and grid connects the input end of described current mirror circuit (103), and drain electrode connects the emitter of described triode (Q1).
3. the step excess temperature compensation holding circuit that drives chip for integrated LED according to claim 1 and 2; it is characterized in that; described differential amplifier (104) comprises the 6th resistance (R5), the 7th resistance (R6), the 8th resistance (R7) and the 3rd amplifier (I2), wherein:
The in-phase input end of described the 3rd amplifier (I2) connects the end that joins of described current mirror circuit (103) and triode (Q1) by described the 8th resistance (R7);
The inverting input of described the 3rd amplifier (I2) connects the end that joins of described current mirror circuit (103) and the 5th resistance (R4) by described the 6th resistance (R5);
The output terminal of described the 3rd amplifier (I2) is as the output terminal of described differential amplifier (104);
Described the 7th resistance (R6) one end connects the inverting input of described the 3rd amplifier (I2), and the other end connects the output terminal of described the 3rd amplifier (I2).
4. the step excess temperature compensation holding circuit that drives chip for integrated LED according to claim 1; it is characterized in that; described step excess temperature compensation holding circuit also comprises reference source circuit (101); reference source circuit (101) comprises band gap reference (I0), the second amplifier (I1) and variable resistor (R3), wherein:
Described band gap reference (I0) is exported described electric current I PATA on the one hand, and output reference voltage signal VBG0 gives the in-phase input end of described the second amplifier (I1) on the other hand;
After joining, the inverting input of described the second amplifier (I1) and output terminal pass through described variable resistor (R3) ground connection;
Described variable resistor (R3) is exported described the first reference voltage V R1 with the end that joins of the second amplifier (I1);
The sliding end of described variable resistor (R3) is exported described the second reference voltage V R2.
5. the step excess temperature compensation holding circuit that drives chip for integrated LED according to claim 1, is characterized in that, described the first comparer (I3) and the second comparer (I4) are the comparer with hysteresis.
6. the step excess temperature compensation holding circuit that drives chip for integrated LED according to claim 3, is characterized in that, the output terminal of described differential amplifier (104) is exported with slope K
tCwith temperature, raise and the linear excess temperature compensating signal VTC declining; Described the first reference voltage V R1 equates when excess temperature compensates threshold value T1 with excess temperature compensating signal VTC; Described the second reference voltage V R2 and excess temperature compensating signal VTC equate when overheat protector threshold value T2.
7. the step excess temperature compensation holding circuit that drives chip for integrated LED according to claim 6, is characterized in that,
When having served as warm compensating signal VTC and being greater than the first reference voltage V R1, the first alternative data selector (S1) is selected its second input end and output terminal connection described in the signal controlling of described the first comparer (I3) output; When having served as warm compensating signal VTC and being less than the first reference voltage V R1, the first alternative data selector (S1) is selected its first input end and output terminal connection described in the signal controlling of described the first comparer (I3) output;
When having served as warm compensating signal VTC and being greater than the second reference voltage V R2, the second alternative data selector (S2) is selected its first input end and output terminal connection described in the signal controlling of described the second comparer (I4) output; When having served as warm compensating signal VTC and being less than the second reference voltage V R2, the second alternative data selector (S2) is selected its second input end and output terminal connection described in the signal controlling of described the second comparer (I4) output.
8. the step excess temperature compensation holding circuit that drives chip for integrated LED according to claim 6, is characterized in that,
The value of excess temperature compensating signal VTC is:
V
TC=(1+R6/R5)*V
BE-(R6/R5)*R4*IPTAT
The slope K of excess temperature compensating signal VTC
tCfor compensation slope, as follows:
K
TC=（1+R6/R5）*K
VBE-（R6/R5）*R4*K
IPTAT
Wherein, R6/R5 represents the ratio of the 7th resistance (R6) and the 6th resistance (R5); V
bErepresent emitter and the base voltage across poles of triode (Q1); R4 represents the value of the 5th resistance (R4); IPTAT represents the current value of the positive temperature coefficient (PTC) of reference circuit generation; K
iPTATrepresent the temperature coefficient constant of the electric current I PTAT of positive temperature coefficient (PTC); K
vBErepresent the voltage V of negative temperature coefficient
bEtemperature coefficient constant.
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| Application Number | Priority Date | Filing Date | Title |
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| CN201320759124.9U CN203588109U (en) | 2013-11-26 | 2013-11-26 | Cascade over-temperature protection circuit for integrated LED drive chips |
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|---|---|---|---|
| CN201320759124.9U CN203588109U (en) | 2013-11-26 | 2013-11-26 | Cascade over-temperature protection circuit for integrated LED drive chips |
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Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN104679089A (en) * | 2013-11-26 | 2015-06-03 | 上海贝岭股份有限公司 | Cascade over-temperature compensation and protection system and circuit for integrated LED (light emitting diode) driving chip |
| CN105846397A (en) * | 2016-03-25 | 2016-08-10 | 厦门新页微电子技术有限公司 | High-precision overtemperature protecting circuit |
| CN108572687A (en) * | 2017-03-09 | 2018-09-25 | 华润矽威科技（上海）有限公司 | A kind of excess temperature compensation circuit and method |
| CN108594922A (en) * | 2018-04-23 | 2018-09-28 | 电子科技大学 | A kind of thermal-shutdown circuit with temperature hysteresis |
| CN109089345A (en) * | 2018-08-14 | 2018-12-25 | 上海艾为电子技术股份有限公司 | Thermal-shutdown circuit and the electronic equipment for applying it |
| CN109696639A (en) * | 2017-10-20 | 2019-04-30 | 意法半导体(鲁塞)公司 | Electronic circuit with the equipment for monitoring power supply |
| CN112213967A (en) * | 2019-07-11 | 2021-01-12 | 深圳市航顺芯片技术研发有限公司 | Automatic detection system for pins received and sent by serial port of microcontroller |
-
2013
- 2013-11-26 CN CN201320759124.9U patent/CN203588109U/en not_active Withdrawn - After Issue
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104679089A (en) * | 2013-11-26 | 2015-06-03 | 上海贝岭股份有限公司 | Cascade over-temperature compensation and protection system and circuit for integrated LED (light emitting diode) driving chip |
| CN104679089B (en) * | 2013-11-26 | 2016-03-09 | 上海贝岭股份有限公司 | Step excess temperature for integrated LED driving chip compensates protection system and circuit |
| CN105846397A (en) * | 2016-03-25 | 2016-08-10 | 厦门新页微电子技术有限公司 | High-precision overtemperature protecting circuit |
| CN108572687A (en) * | 2017-03-09 | 2018-09-25 | 华润矽威科技（上海）有限公司 | A kind of excess temperature compensation circuit and method |
| CN108572687B (en) * | 2017-03-09 | 2020-04-28 | 华润矽威科技（上海）有限公司 | Over-temperature compensation circuit and method |
| CN109696639A (en) * | 2017-10-20 | 2019-04-30 | 意法半导体(鲁塞)公司 | Electronic circuit with the equipment for monitoring power supply |
| CN109696639B (en) * | 2017-10-20 | 2021-03-26 | 意法半导体(鲁塞)公司 | Electronic circuit with device for monitoring power supply |
| CN108594922A (en) * | 2018-04-23 | 2018-09-28 | 电子科技大学 | A kind of thermal-shutdown circuit with temperature hysteresis |
| CN109089345A (en) * | 2018-08-14 | 2018-12-25 | 上海艾为电子技术股份有限公司 | Thermal-shutdown circuit and the electronic equipment for applying it |
| CN109089345B (en) * | 2018-08-14 | 2024-03-22 | 上海艾为电子技术股份有限公司 | Over-temperature protection circuit and electronic equipment applying same |
| CN112213967A (en) * | 2019-07-11 | 2021-01-12 | 深圳市航顺芯片技术研发有限公司 | Automatic detection system for pins received and sent by serial port of microcontroller |
| CN112213967B (en) * | 2019-07-11 | 2021-07-02 | 深圳市航顺芯片技术研发有限公司 | Automatic detection system for pins received and sent by serial port of microcontroller |
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