CN104362585A - Over-temperature protection circuit - Google Patents
Over-temperature protection circuit Download PDFInfo
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- CN104362585A CN104362585A CN201410606497.1A CN201410606497A CN104362585A CN 104362585 A CN104362585 A CN 104362585A CN 201410606497 A CN201410606497 A CN 201410606497A CN 104362585 A CN104362585 A CN 104362585A
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Abstract
The invention provides an over-temperature protection circuit which comprises an over-temperature detecting circuit and a signal output circuit. The over-temperature detecting circuit generates a first current and a second current, compares the two, and outputs an over-temperature detecting signal indicating whether the temperature exceeds an over-temperature protection threshold or not according to the comparison result of the first current and the second current, wherein the temperature coefficient of the first current is different from the temperature coefficient of the second current. The signal output circuit is driven by the over-temperature detecting signal to output an over-temperature protection signal indicating whether the temperature exceeds an over-temperature protection threshold or not. Compared with the prior art, the improved over-temperature protection circuit has the advantage that the over-temperature protection signal can be output to control a chip to enter a temperature protection state when the temperature of the chip is excessively high.
Description
[technical field]
The present invention relates to circuit design field, particularly a kind of thermal-shutdown circuit be integrated in chip.
[background technology]
In various Circuits System, may there is the situation that temperature is too high in the system that particularly power is larger.In order to improve the reliability of circuit and device; general power circuit is all provided with thermal-shutdown circuit; the function of usual thermal-shutdown circuit is the temperature of testing circuit, and when exceeding preset temperature threshold value, its control circuit quits work or reduces circuit output current.
In integrated circuit (or chip), be integrated with the circuit of power device, such as charger, pressurizer etc. are all integrated with thermal-shutdown circuit on chip.But the existing thermal-shutdown circuit be integrated in chip also exists a lot of not enough on stuctures and properties.
Therefore, the technical scheme of the thermal-shutdown circuit that a kind of improvement is provided is necessary.
[summary of the invention]
The object of the present invention is to provide a kind of thermal-shutdown circuit, it can realize when chip temperature is too high, and export overheat protector signal, control chip enters temperature protection state.
In order to solve the problem, the invention provides a kind of thermal-shutdown circuit, it comprises excess temperature testing circuit and signal output apparatus.Described excess temperature testing circuit generates the first electric current and the second electric current; and compare the first electric current and the second electric current; comparative result output based on the first electric current and the second electric current represents whether temperature exceedes the excess temperature detection signal of temperature protection threshold value; wherein the temperature coefficient of the first electric current is different from the temperature coefficient of the second electric current, and described signal output apparatus exports and represents whether temperature exceedes the overheat protector signal of temperature protection threshold value under the driving of described excess temperature detection signal.
Further; at the overheat protector signal that described signal output apparatus exports by representing that the state transition that temperature does not exceed temperature protection threshold value is when representing that temperature exceedes the state of temperature protection threshold value; the current value of described second electric current is decreased to the second value by the first value; at the overheat protector signal that described signal output apparatus exports by representing that the state transition that temperature exceedes temperature protection threshold value is, when representing that temperature does not exceed the state of temperature protection threshold value, the current value of described second electric current is increased to the first value by the second value.
Further, described excess temperature testing circuit comprises PMOS transistor MP1, MP2, MP3, MP4, nmos pass transistor MN1, MN2, MN3, MN4, bipolar transistor Q1, Q2, resistance R1, R2.PMOS transistor MP1, MP2, MP3 are all connected with power end VIN with the source electrode of MP4, and the grid of PMOS transistor MP1, MP2, MP3 and MP4 is connected to each other, and the grid of PMOS transistor MP1 is connected with its drain electrode; Nmos pass transistor MN1, MN2, MN3 are connected with the drain electrode of MP4 with PMOS transistor MP1, MP2, MP3 respectively with the drain electrode of MN4, the gate interconnection of nmos pass transistor MN2, MN3 and MN4, and the grid of nmos pass transistor MN1 is connected with the drain electrode of nmos pass transistor MN2; The source electrode of nmos pass transistor MN2 is connected with the emitter of bipolar transistor Q1, the collector electrode of bipolar transistor Q1 is connected with ground node GND, the source electrode of nmos pass transistor MN3 is connected with the emitter of bipolar transistor Q2 through resistance R1, the collector electrode of bipolar transistor Q2 and ground node GND, the source electrode of nmos pass transistor MN4 is connected with ground node GND through resistance R2; The base stage of bipolar transistor Q1 is connected to ground node GND after being connected with the base stage of Q2; The source electrode of nmos pass transistor MN1 is connected with the source class of nmos pass transistor MN3.Electric current on PMOS transistor MP4 is the first electric current; Electric current on nmos pass transistor MN4 is the second electric current; Connected node between PMOS transistor MP4 and nmos pass transistor MN4 is the output of described excess temperature testing circuit.
Further, described signal output apparatus comprises PMOS transistor MP5, current source I3 and inverter INV1.The grid of PMOS transistor MP5 is connected with the output of described excess temperature testing circuit, and its source electrode is connected with described power end VIN, and its drain electrode is connected with the input of described current source I3, and the output of current source I3 is connected with ground node GND; The input of inverter INV1 is connected with the connected node between PMOS transistor and current source I3, and its output is connected with the output of described signal output apparatus.
Further, when the first electric current is greater than the second electric current, the output of described excess temperature testing circuit becomes high level signal, and now PMOS transistor MP5 turns off, and inverter INV1 exports high level signal, represents that temperature exceedes temperature protection threshold value.
Further, described excess temperature testing circuit also comprises resistance R3 and the switching device in parallel with described resistance R3.Described resistance R3 and described resistance R2 is series between the source class of nmos pass transistor MN4 and ground node GND; The control end of described switching device is connected with the output of described signal output apparatus; when the overheat protector signal indication temperature that described signal output apparatus exports exceedes temperature protection threshold value; described switching device cut-off; when the non-temperature of overheat protector signal indication that described signal output apparatus exports exceedes temperature protection threshold value, described switch device conductive.
Further; described thermal-shutdown circuit also comprises start-up circuit; the output of described start-up circuit is connected with the grid of the nmos pass transistor MN1 in excess temperature testing circuit, described start-up circuit by the grid Injection Current of nmos pass transistor MN1 to start described excess temperature detection circuit.
Further, described start-up circuit comprises PMOS transistor MP6, MP7 and MP8, and the source electrode of described PMOS transistor MP6 is connected with described power end VIN, and its grid is connected with the grid of PMOS transistor MP1; The source electrode of PMOS transistor MP8 is connected with described power end VIN, and its grid is connected with the drain electrode of PMOS transistor MP6, and its drain electrode is connected with the grid of described nmos pass transistor MN1 as the output of described start-up circuit; The lining body of described PMOS transistor MP7 is connected with the drain electrode of PMOS transistor MP6, and its source electrode, grid and drain electrode are all connected with ground node GND.When described excess temperature testing circuit does not start, the electric current on PMOS transistor MP6 is less than the leakage current of the lining body of PMOS transistor MP7, causes PMOS transistor MP8 conducting, Injection Current to the grid of nmos pass transistor MN1, to start described excess temperature testing circuit; After described excess temperature testing circuit starts, the electric current on described PMOS transistor MP6 is greater than the leakage current of the lining body of PMOS transistor MP7, causes PMOS transistor MP8 to turn off.
Further, the electric current flowing through bipolar transistor Q1 is greater than the electric current flowing through described bipolar transistor Q2; Or the ratio of the emitter area of bipolar transistor Q2 and Q1 is greater than 1, the first electric current is positive temperature coefficient, and the second electric current is negative temperature coefficient, and this thermal-shutdown circuit is integrated in a chip.
Further; described thermal-shutdown circuit also comprises reference current generating circuit; described reference current generating circuit comprises PMOS transistor MP9; the source electrode of described transistor MP9 is connected with described power end VIN; its grid is connected with the grid of described PMOS transistor MP1; its drain electrode is as the output of this reference current generating circuit, and excess temperature testing circuit also comprises four PMOS transistor of connecting with PMOS transistor MP1, MP2, MP3, MP4 respectively, to form cascade current mirror structure.
Compared with prior art; first electric current and second electric current of different temperature coefficients are set in the thermal-shutdown circuit in the present invention; the change of temperature can cause the current value of the current value of the first electric current and the second electric current that different changes occurs; when temperature exceedes temperature protection threshold value; the magnitude relationship of the current value of the first electric current and the second electric current will overturn; whether the temperature carrying out decision circuit based on this exceedes temperature protection threshold value; to realize when chip temperature is too high; export overheat protector signal, control chip enters temperature protection state.
[accompanying drawing explanation]
In order to be illustrated more clearly in the technical scheme of the embodiment of the present invention, below the accompanying drawing used required in describing embodiment is briefly described, apparently, accompanying drawing in the following describes is only some embodiments of the present invention, for those of ordinary skill in the art, under the prerequisite not paying creative work, other accompanying drawing can also be obtained according to these accompanying drawings.Wherein:
Fig. 1 is the thermal-shutdown circuit circuit diagram in one embodiment in the present invention;
Fig. 2 is the thermal-shutdown circuit circuit diagram in another embodiment in the present invention.
[embodiment]
In order to be illustrated more clearly in the technical scheme of the embodiment of the present invention, below the accompanying drawing used required in describing embodiment is briefly described, apparently, accompanying drawing in the following describes is only some embodiments of the present invention, for those of ordinary skill in the art, under the prerequisite not paying creative work, other accompanying drawing can also be obtained according to these accompanying drawings.
Please refer to shown in Fig. 1, it is the circuit diagram of the present invention's thermal-shutdown circuit in one embodiment.This thermal-shutdown circuit comprises excess temperature testing circuit 110 and signal output apparatus 120.
Described excess temperature testing circuit 110 generates the first electric current I 1 and the second electric current I 2; and compare the size of current of the first electric current and the second electric current; comparative result output based on the first electric current I 1 and the second electric current I 2 represents whether temperature exceedes the excess temperature detection signal of temperature protection threshold value, and wherein the temperature coefficient of the first electric current is different from the temperature coefficient of the second electric current.Because the first electric current is different with the temperature coefficient of the second electric current; the change of temperature can cause the current value of the current value of the first electric current and the second electric current that different changes occurs; by suitable setting; when temperature exceedes temperature protection threshold value; the magnitude relationship of the current value of the first electric current and the second electric current will overturn, and the comparative result output like this based on the first electric current and the second electric current represents whether temperature exceedes the excess temperature detection signal of temperature protection threshold value.In preferred embodiment, wherein the first electric current is positive temperature coefficient, namely the current value of the first electric current can become large along with increasing of temperature, second electric current is negative temperature coefficient, namely the current value of the second electric current can reduce along with increasing of temperature, can increase the susceptibility of comparative result to variations in temperature of the first electric current and the second electric current like this, precision improves.
Described signal output apparatus 120 exports and represents whether temperature exceedes the overheat protector signal OTP of temperature protection threshold value under the driving of described excess temperature detection signal.
In one embodiment; at the overheat protector signal that described signal output apparatus 120 exports by representing that the state transition that temperature does not exceed temperature protection threshold value is when representing that temperature exceedes the state of temperature protection threshold value; the current value of described second electric current I 2 is decreased to the second value by the first value; at the overheat protector signal that described signal output apparatus 120 exports by representing that the state transition that temperature exceedes temperature protection threshold value is, when representing that temperature does not exceed the state of temperature protection threshold value, the current value of described second electric current I 2 is increased to the first value by the second value.Can avoid like this, when temperature is positioned at described temperature protection Near Threshold, there is vibration in described overheat protector signal, realizes hesitation.
In one embodiment, continue referring to shown in Fig. 1, described excess temperature testing circuit 110 comprises PMOS transistor MP1, MP2, MP3, MP4, nmos pass transistor MN1, MN2, MN3, MN4, bipolar transistor Q1, Q2, resistance R1, R2 and R3, switching device MN5.
PMOS transistor MP1, MP2, MP3 are all connected with power end VIN with the source electrode of MP4, and the grid of PMOS transistor MP1, MP2, MP3 and MP4 is connected to each other, and the grid of PMOS transistor MP1 is connected with its drain electrode; Nmos pass transistor MN1, MN2, MN3 are connected with the drain electrode of MP4 with PMOS transistor MP1, MP2, MP3 respectively with the drain electrode of MN4, the gate interconnection of nmos pass transistor MN2, MN3 and MN4, and the grid of nmos pass transistor MN1 is connected with the drain electrode of nmos pass transistor MN2; The source electrode of nmos pass transistor MN2 is connected with the emitter of bipolar transistor Q1, the collector electrode of bipolar transistor Q1 is connected with ground node GND, the source electrode of nmos pass transistor MN3 is connected with the emitter of bipolar transistor Q2 through resistance R1, the collector electrode of bipolar transistor Q2 and ground node GND, the source electrode of nmos pass transistor MN4 is connected with ground node GND with resistance R3 through resistance R2; The base stage of bipolar transistor Q1 is connected to ground node GND after being connected with the base stage of Q2; The source electrode of nmos pass transistor MN1 is connected with the source class of nmos pass transistor MN3.The lining body of nmos pass transistor MN1, MN2, MN3, MN4 is connected with ground node GND.The electric current flowing through PMOS transistor MP4 is the first electric current, and the electric current flow through on nmos pass transistor MN4 is the second electric current; Connected node between PMOS transistor MP4 and nmos pass transistor MN4 is the output of described excess temperature testing circuit 110.
Switching device MN5 is in parallel with resistance R3, and the output of signal output apparatus 120 is connected with the control end of switching device MN5 through inverter INV2.In this embodiment, described switching device MN5 is nmos pass transistor, and control end is its grid.When the overheat protector signal OTP that described signal output apparatus 120 exports represents that temperature exceedes temperature protection threshold value; described switching device MN5 ends; when the overheat protector signal OTP that described signal output apparatus 120 exports represents that non-temperature exceedes temperature protection threshold value, described switching device MN5 conducting.
Described signal output apparatus 120 comprises PMOS transistor MP5, current source I3 and inverter INV1.The grid of PMOS transistor MP5 is connected with the output of described excess temperature testing circuit 110, and its source electrode is connected with described power end VIN, and its drain electrode is connected with the input of described current source I3, and the output of current source I3 is connected with ground node GND; The input of inverter INV1 is connected with the connected node between PMOS transistor and current source I3, and its output is connected with the output of described signal output apparatus.
In this embodiment, described bipolar transistor Q1 and Q2 is positive-negative-positive bipolar transistor.
Introduce the operation principle of the described thermal-shutdown circuit in Fig. 1 below.
MP1, MP2, MP3, MP4 form current mirror, and its current ratio can be designed as 1:1:1:1 (conveniently explain understanding, just illustrate like this, actual design is decided to be 1:1:1:1:1 without the need to).It (is the gate source voltage of MN1 that MN1 helps the drain-source voltage of MN2 to be adjusted to Vgs1, close to Vthn, Vthn is the threshold voltage of NMOS tube), and the drain-source voltage of MN3 equals Vgs3 (is the gate source voltage of MN3, close to Vthn, Vthn is the threshold voltage of NMOS tube), the drain-source voltage of such MN2 is close to the drain-source voltage equaling MN3.MN2 and MN3 adjustment makes both source voltages equal,
Then Vbe1=Vbe2+VR1=Vbe2+IQ2.R1=Vbe2+Ip3.R1, (1)
Wherein Vbe1 is the base emitter voltage of bipolar transistor Q1, and Vbe2 is the base emitter voltage of bipolar transistor Q2, and VR1 is the voltage at resistance R1 two ends, and IQ2 is the electric current flowing through Q2, and Ip3 is the electric current flowing through MP3.According to KCL law: IQ2 equals Ip3.Can be obtained by formula (1): Ip3=(Vbe1-Vbe2)/R1=Δ Vbe/R1.Like this, MN1, MN2, MN3, MP1, MP2, MP3, resistance R1, PNP pipe Q1 and Q2 produce the electric current of Δ Vbe/R1.So, the electric current flowing through MP4 also just equals Δ Vbe/R1.
In addition; MN4 and MN2 adopts matched design; make its source voltage equal; voltage on such R2 and R3 equals the base emitter voltage Vbe1 of transistor Q1; when excess temperature guard signal OTP is low level, MN5 is in conducting state, and the electric current of MN4 equals Vbe1/R2; wherein Vbe1 is the base emitter voltage of Q1, and R2 is the resistance value of resistance R2.The electric current of MP4 and the electric current of MN4 are competed, and produce temperature comparative result.The current replication of MP4, in the electric current of MP1 and MP3, equals (Vbe1-Vbe2)/R1.According to PNP transistor characteristic, (Vbe1-Vbe2) is positive temperature coefficient voltage, is proportional to temperature.And Vbe1 is negative temperature coefficient voltage, the temperature coefficient of negligible resistance, then MP4 and MN4 represents the electric current competition of different temperature coefficients.Along with temperature raises, the electric current of MP4 increases, and the electric current of MN4 reduces simultaneously, and when MP4 electric current is greater than MN4 electric current, MP5 grid voltage raises, and cause MP5 to turn off, the input of inverter INV1 becomes low level, and OTP becomes high level.MP5 and current source I3 forms common source amplifying stage.
MN5 is that high level (represents that temperature exceedes temperature protection threshold value at overheat protector signal OTP, enter overheat protector state) time cut-off (its grid is low level), overheat protector signal OTP be low level (represent temperature do not exceed temperature protection threshold value, enter non-overheat protector state) time conducting (its grid is high level), its effect is the sluggishness producing temperature protection, when never overheat protector state enters overheat protector state, turn threshold is higher, such as temperature protection threshold value is 150 DEG C, when being withdrawn into non-excess temperature guard mode (normal operating conditions) from overheat protector state, turn threshold is lower, such as temperature threshold is 130 DEG C.When never overheat protector state enters overheat protector state, realization be the comparison of (Vbe1-Vbe2)/R1 and Vbe1/R2 (it can be called as the first value of the first electric current); When being withdrawn into nonprotected state from overheat protector state, realization be the comparison of (Vbe1-Vbe2)/R1 and Vbe1/ (R2+R3) (it can be called as the second value of the first electric current, and two value ratio first is worth little obviously).Two the temperature protection threshold values solved like this there are differences, and design is called as hesitation, in order to prevent frequently vibrating near temperature protection point like this.
In an embodiment that can substitute, resistance R3, switching device MN5 also can not be set, resistance R2 can be made to be directly connected between the source class of MN4 and ground node.In this embodiment, without hesitation, but described thermal-shutdown circuit still can realize basic overheat protector function.
In one embodiment, current source I3 can copy generation by current mirror from MP1.In order to improve the precision of temperature protection threshold value, in an advantageous embodiment, the electric current (equaling the electric current of Q1) of design MP2 is greater than the electric current sum (i.e. the electric current of Q2) of MP3 and MP1, and such as its ratio is 4:1.The ratio of the emitter area of bipolar transistor Q2 and Q1 is larger, also contributes to the precision improving temperature protection threshold value.Its reason is the ratio that Δ Vbe=Vbe1-Vbe2 depends on the current density of Q1 and Q2, and the ratio of its current density is larger, and the value of Δ Vbe is larger, and the misalignment voltage of opposing MN2 and MN3 is stronger.Suppose that the misalignment voltage of MN2 and MN3 is Vos, then Δ Vbe/Vos is larger, and the error that Vos introduces is less.In integrated circuit high volume production process, can there is mismatch in the parameters such as the threshold voltage of MOS, causes error like this.
For excess temperature testing circuit 110, need start-up circuit to start, avoid zero current condition.As shown in Figure 1, described thermal-shutdown circuit also includes start-up circuit 130.The output of described start-up circuit 130 is connected with the grid of the nmos pass transistor MN1 in excess temperature testing circuit, described start-up circuit 130 by the grid Injection Current to nmos pass transistor MN1 to start described excess temperature detection circuit 110.
Fig. 2 is the thermal-shutdown circuit circuit diagram in another embodiment in the present invention.In this embodiment, the excess temperature testing circuit 210 that the described thermal-shutdown circuit in Fig. 2 comprises is identical with Fig. 1 with signal output apparatus 220 structure.
Fig. 2 illustrates an embodiment of start-up circuit 230.Described start-up circuit 230 comprises PMOS transistor MP6, MP7 and MP8, and the source electrode of described PMOS transistor MP6 is connected with described power end VIN, and its grid is connected with the grid of PMOS transistor MP1; The source electrode of PMOS transistor MP8 is connected with described power end VIN, and its grid is connected with the drain electrode of PMOS transistor MP6, and its drain electrode is connected with the grid of described nmos pass transistor MN1 as the output of described start-up circuit 230; The lining body of described PMOS transistor MP7 is connected with the drain electrode of PMOS transistor MP6, and its source electrode, grid and drain electrode are all connected with ground node GND.When described excess temperature testing circuit 210 does not start, electric current on PMOS transistor MP6 is less than the leakage current of the lining body of PMOS transistor MP7, cause PMOS transistor MP8 conducting, Injection Current to the grid of nmos pass transistor MN1, to start described excess temperature testing circuit 210.After described excess temperature testing circuit 210 starts, the electric current on described PMOS transistor MP6 is greater than the leakage current of the lining body of PMOS transistor MP7, causes PMOS transistor MP8 to turn off.
In addition, the thermal-shutdown circuit in Fig. 2 also comprises reference current generating circuit 240.Described reference current generating circuit 240 comprises PMOS transistor MP9, and the source electrode of described transistor MP9 is connected with described power end VIN, and its grid is connected with the grid of described PMOS transistor MP1, and its drain electrode is as the output of this reference current generating circuit.In prior art, general employing two circuit realize excess temperature detection and bias current generating circuit respectively, and implementation of the present invention can make chip area less.
In a preferred embodiment; described excess temperature testing circuit 210 also comprises four PMOS transistor of connecting with PMOS transistor MP1, MP2, MP3, MP4 respectively; to form cascade current mirror structure; the impact of mains voltage variations on current precision and overheat protector threshold value can be reduced, namely improve the precision of output current and overheat protector threshold value.
Thermal-shutdown circuit in the present invention can be integrated in chip piece.
In the present invention, " connection ", be connected, word that " companys ", the expression such as " connecing " are electrical connected, if no special instructions, then represent direct or indirect electric connection.
It is pointed out that the scope be familiar with person skilled in art and any change that the specific embodiment of the present invention is done all do not departed to claims of the present invention.Correspondingly, the scope of claim of the present invention is also not limited only to previous embodiment.
Claims (10)
1. a thermal-shutdown circuit, is characterized in that, it comprises excess temperature testing circuit and signal output apparatus,
Described excess temperature testing circuit generates the first electric current and the second electric current; and compare the first electric current and the second electric current; comparative result output based on the first electric current and the second electric current represents whether temperature exceedes the excess temperature detection signal of temperature protection threshold value; wherein the temperature coefficient of the first electric current is different from the temperature coefficient of the second electric current
Described signal output apparatus exports and represents whether temperature exceedes the overheat protector signal of temperature protection threshold value under the driving of described excess temperature detection signal.
2. thermal-shutdown circuit according to claim 1; it is characterized in that; at the overheat protector signal that described signal output apparatus exports by representing that the state transition that temperature does not exceed temperature protection threshold value is when representing that temperature exceedes the state of temperature protection threshold value; the current value of described second electric current is decreased to the second value by the first value
At the overheat protector signal that described signal output apparatus exports by representing that the state transition that temperature exceedes temperature protection threshold value is, when representing that temperature does not exceed the state of temperature protection threshold value, the current value of described second electric current is increased to the first value by the second value.
3. thermal-shutdown circuit according to claim 1 and 2, is characterized in that, described excess temperature testing circuit comprises PMOS transistor MP1, MP2, MP3, MP4, nmos pass transistor MN1, MN2, MN3, MN4, bipolar transistor Q1, Q2, resistance R1, R2,
PMOS transistor MP1, MP2, MP3 are all connected with power end VIN with the source electrode of MP4, and the grid of PMOS transistor MP1, MP2, MP3 and MP4 is connected to each other, and the grid of PMOS transistor MP1 is connected with its drain electrode; Nmos pass transistor MN1, MN2, MN3 are connected with the drain electrode of MP4 with PMOS transistor MP1, MP2, MP3 respectively with the drain electrode of MN4, the gate interconnection of nmos pass transistor MN2, MN3 and MN4, and the grid of nmos pass transistor MN1 is connected with the drain electrode of nmos pass transistor MN2; The source electrode of nmos pass transistor MN2 is connected with the emitter of bipolar transistor Q1, the collector electrode of bipolar transistor Q1 is connected with ground node GND, the source electrode of nmos pass transistor MN3 is connected with the emitter of bipolar transistor Q2 through resistance R1, the collector electrode of bipolar transistor Q2 and ground node GND, the source electrode of nmos pass transistor MN4 is connected with ground node GND through resistance R2; The base stage of bipolar transistor Q1 is connected to ground node GND after being connected with the base stage of Q2; The source electrode of nmos pass transistor MN1 is connected with the source class of nmos pass transistor MN3,
Electric current on PMOS transistor MP4 is the first electric current; Electric current on nmos pass transistor MN4 is the second electric current; Connected node between PMOS transistor MP4 and nmos pass transistor MN4 is the output of described excess temperature testing circuit.
4. thermal-shutdown circuit according to claim 3, is characterized in that, described signal output apparatus comprises PMOS transistor MP5, current source I3 and inverter INV1,
The grid of PMOS transistor MP5 is connected with the output of described excess temperature testing circuit, and its source electrode is connected with described power end VIN, and its drain electrode is connected with the input of described current source I3, and the output of current source I3 is connected with ground node GND; The input of inverter INV1 is connected with the connected node between PMOS transistor and current source I3, and its output is connected with the output of described signal output apparatus.
5. thermal-shutdown circuit according to claim 4, is characterized in that,
When the first electric current is greater than the second electric current, the output of described excess temperature testing circuit becomes high level signal, and now PMOS transistor MP5 turns off, and inverter INV1 exports high level signal, represents that temperature exceedes temperature protection threshold value.
6. thermal-shutdown circuit according to claim 3, is characterized in that, described excess temperature testing circuit also comprises resistance R3 and the switching device in parallel with described resistance R3,
Described resistance R3 and described resistance R2 is series between the source class of nmos pass transistor MN4 and ground node GND; The control end of described switching device is connected with the output of described signal output apparatus,
When the overheat protector signal indication temperature that described signal output apparatus exports exceedes temperature protection threshold value, described switching device cut-off,
When the non-temperature of overheat protector signal indication that described signal output apparatus exports exceedes temperature protection threshold value, described switch device conductive.
7. thermal-shutdown circuit according to claim 3; it is characterized in that; it also comprises start-up circuit; the output of described start-up circuit is connected with the grid of the nmos pass transistor MN1 in excess temperature testing circuit, described start-up circuit by the grid Injection Current of nmos pass transistor MN1 to start described excess temperature detection circuit.
8. thermal-shutdown circuit according to claim 7, is characterized in that,
Described start-up circuit comprises PMOS transistor MP6, MP7 and MP8, and the source electrode of described PMOS transistor MP6 is connected with described power end VIN, and its grid is connected with the grid of PMOS transistor MP1; The source electrode of PMOS transistor MP8 is connected with described power end VIN, and its grid is connected with the drain electrode of PMOS transistor MP6, and its drain electrode is connected with the grid of described nmos pass transistor MN1 as the output of described start-up circuit; The lining body of described PMOS transistor MP7 is connected with the drain electrode of PMOS transistor MP6, and its source electrode, grid and drain electrode are all connected with ground node GND,
When described excess temperature testing circuit does not start, the electric current on PMOS transistor MP6 is less than the leakage current of the lining body of PMOS transistor MP7, causes PMOS transistor MP8 conducting, Injection Current to the grid of nmos pass transistor MN1, to start described excess temperature testing circuit;
After described excess temperature testing circuit starts, the electric current on described PMOS transistor MP6 is greater than the leakage current of the lining body of PMOS transistor MP7, causes PMOS transistor MP8 to turn off.
9. thermal-shutdown circuit according to claim 3, is characterized in that,
The electric current flowing through bipolar transistor Q1 is greater than the electric current flowing through described bipolar transistor Q2; Or
The ratio of the emitter area of bipolar transistor Q2 and Q1 is greater than 1, and the first electric current is positive temperature coefficient, and the second electric current is negative temperature coefficient, and this thermal-shutdown circuit is integrated in a chip.
10. thermal-shutdown circuit according to claim 3; it is characterized in that; it also comprises reference current generating circuit; described reference current generating circuit comprises PMOS transistor MP9; the source electrode of described transistor MP9 is connected with described power end VIN; its grid is connected with the grid of described PMOS transistor MP1; its drain electrode is as the output of this reference current generating circuit; excess temperature testing circuit also comprises four PMOS transistor of connecting with PMOS transistor MP1, MP2, MP3, MP4 respectively, to form cascade current mirror structure.
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Cited By (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104993454A (en) * | 2015-06-29 | 2015-10-21 | 中国电子科技集团公司第五十八研究所 | Over-temperature protection circuit |
| CN107171291A (en) * | 2017-05-12 | 2017-09-15 | 南京中感微电子有限公司 | A kind of chip protection circuit and system |
| CN107732870A (en) * | 2017-08-31 | 2018-02-23 | 北京时代民芯科技有限公司 | A kind of configurable thermal-shutdown circuit applied to Switching Power Supply |
| CN108446204A (en) * | 2018-03-30 | 2018-08-24 | 联想(北京)有限公司 | A kind of chip and electronic equipment |
| 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 |
| CN109521831A (en) * | 2019-01-09 | 2019-03-26 | 上海奥令科电子科技有限公司 | A kind of temperature protection circuit |
| CN112068631A (en) * | 2020-09-24 | 2020-12-11 | 电子科技大学 | Anti-interference excess temperature protection circuit of low-power consumption |
| CN112165072A (en) * | 2020-09-28 | 2021-01-01 | 上海芯龙半导体技术股份有限公司 | Over-temperature protection circuit and power supply chip |
| CN112362180A (en) * | 2020-10-15 | 2021-02-12 | 国网思极紫光(青岛)微电子科技有限公司 | Temperature difference detection circuit for over-temperature protection |
| CN113114210A (en) * | 2021-04-21 | 2021-07-13 | 电子科技大学 | Self-bias over-temperature protection circuit |
| CN114185387A (en) * | 2021-10-25 | 2022-03-15 | 西安电子科技大学芜湖研究院 | Low-power-consumption over-temperature protection circuit based on current comparator |
| CN115855289A (en) * | 2023-02-14 | 2023-03-28 | 晶艺半导体有限公司 | Temperature detection module and over-temperature protection circuit |
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Cited By (21)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104993454B (en) * | 2015-06-29 | 2018-12-04 | 中国电子科技集团公司第五十八研究所 | Thermal-shutdown circuit |
| CN104993454A (en) * | 2015-06-29 | 2015-10-21 | 中国电子科技集团公司第五十八研究所 | Over-temperature protection circuit |
| CN107171291A (en) * | 2017-05-12 | 2017-09-15 | 南京中感微电子有限公司 | A kind of chip protection circuit and system |
| CN107732870B (en) * | 2017-08-31 | 2019-06-04 | 北京时代民芯科技有限公司 | A kind of configurable thermal-shutdown circuit applied to Switching Power Supply |
| CN107732870A (en) * | 2017-08-31 | 2018-02-23 | 北京时代民芯科技有限公司 | A kind of configurable thermal-shutdown circuit applied to Switching Power Supply |
| CN108446204A (en) * | 2018-03-30 | 2018-08-24 | 联想(北京)有限公司 | A kind of chip and electronic equipment |
| CN108446204B (en) * | 2018-03-30 | 2021-09-14 | 联想(北京)有限公司 | Chip and electronic equipment |
| 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 |
| CN109521831A (en) * | 2019-01-09 | 2019-03-26 | 上海奥令科电子科技有限公司 | A kind of temperature protection circuit |
| CN112068631A (en) * | 2020-09-24 | 2020-12-11 | 电子科技大学 | Anti-interference excess temperature protection circuit of low-power consumption |
| CN112068631B (en) * | 2020-09-24 | 2021-06-08 | 电子科技大学 | Anti-interference excess temperature protection circuit of low-power consumption |
| CN112165072A (en) * | 2020-09-28 | 2021-01-01 | 上海芯龙半导体技术股份有限公司 | Over-temperature protection circuit and power supply chip |
| CN112165072B (en) * | 2020-09-28 | 2023-03-10 | 上海芯龙半导体技术股份有限公司 | Over-temperature protection circuit and power chip |
| CN112362180A (en) * | 2020-10-15 | 2021-02-12 | 国网思极紫光(青岛)微电子科技有限公司 | Temperature difference detection circuit for over-temperature protection |
| CN113114210A (en) * | 2021-04-21 | 2021-07-13 | 电子科技大学 | Self-bias over-temperature protection circuit |
| CN113114210B (en) * | 2021-04-21 | 2022-05-17 | 电子科技大学 | Self-bias over-temperature protection circuit |
| CN114185387A (en) * | 2021-10-25 | 2022-03-15 | 西安电子科技大学芜湖研究院 | Low-power-consumption over-temperature protection circuit based on current comparator |
| CN115855289A (en) * | 2023-02-14 | 2023-03-28 | 晶艺半导体有限公司 | Temperature detection module and over-temperature protection circuit |
| CN115855289B (en) * | 2023-02-14 | 2023-05-02 | 晶艺半导体有限公司 | Temperature detection module and over-temperature protection circuit |
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