CN105318984A - Over-temperature detection circuit - Google Patents
Over-temperature detection circuit Download PDFInfo
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- CN105318984A CN105318984A CN201410344109.7A CN201410344109A CN105318984A CN 105318984 A CN105318984 A CN 105318984A CN 201410344109 A CN201410344109 A CN 201410344109A CN 105318984 A CN105318984 A CN 105318984A
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- voltage
- detection circuit
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- resistance
- temperature
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- 238000001514 detection method Methods 0.000 title claims abstract description 42
- 238000004519 manufacturing process Methods 0.000 abstract description 7
- 238000010586 diagram Methods 0.000 description 9
- 230000007704 transition Effects 0.000 description 3
- 230000000007 visual effect Effects 0.000 description 3
- 230000007423 decrease Effects 0.000 description 2
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 1
- 230000002159 abnormal effect Effects 0.000 description 1
- 230000003139 buffering effect Effects 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000002950 deficient Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000005669 field effect Effects 0.000 description 1
- 230000000630 rising effect Effects 0.000 description 1
Abstract
The invention provides an over-temperature detection circuit, which comprises a first voltage division circuit, a second voltage division circuit and a comparator. The first voltage division circuit comprises a plurality of resistors and a first voltage divider, wherein one of the plurality of resistors is a thermistor; the second voltage division circuit comprises a plurality of resistors and is used for outputting a second voltage; the comparator includes a first input terminal, a second input terminal and an output terminal. The first input end is used for receiving the first voltage; the second input terminal is used for receiving the second voltage. The comparator generates an output signal to the output terminal according to the first voltage and the second voltage. The over-temperature detection circuit can detect whether the ambient temperature of the specific element exceeds the normal range or not, and avoid the specific element from being burnt due to the over-temperature phenomenon caused by poor manufacturing process factors.
Description
Technical field
The invention relates to a kind of excess temperature detection circuit, espespecially a kind of excess temperature detection circuit detecting particular element excess temperature phenomenon.
Background technology
In existing power supply administrative skill, the mechanism of overcurrent protection and short-circuit protection is all present in power management chip.But; Individual elements is as mos field effect transistor (MetalOxideSemiconductorFieldEffectTransistor; MOSFET) undesirable element; as bad in manufacture craft, deficient purchase or to eat tin bad etc., is not contained in the desired extent of existing over current protection protection mechanism.Specifically, as elements such as MOSFET, because manufacture craft is bad etc., factor can cause this element and printed circuit board (PCB) (PrintedCircuitBoard, PCB) there is high impedance between, and can abnormal temperature be caused when making normal current flow through this element.In other words, when the electric current flowing through this element is not yet enough to start the over current protection protection mechanism of power management chip, that causes because of factors such as manufacture craft are bad crosses high impedance the temperature of this element may be made still constantly to raise.In the course of time, this element when normal current operates, still may Yin Wendu too high and burn.This phenomenon not only makes associated circuitry cannot normal operation, even causes the damage that printed circuit board (PCB) is more serious.
In view of this, provide a kind of excess temperature detection circuit for particular element, to detect the environment temperature whether overrun of this particular element, become one of target that industry makes great efforts.
Summary of the invention
Therefore, the invention provides a kind of excess temperature detection circuit, to detect the environment temperature whether overrun of this particular element for particular element.
The present invention discloses a kind of excess temperature detection circuit, includes one first bleeder circuit, one second bleeder circuit and a comparer.This first bleeder circuit includes multiple resistance, is used for output one first voltage, and a resistance in the plurality of resistance is thermistor; This second bleeder circuit includes multiple resistance, is used for output one second voltage; This comparer includes a first input end, one second input end and an output terminal.This first input end is coupled to the first bleeder circuit, is used for receiving this first voltage; This second input end is coupled to the second bleeder circuit, is used for receiving this second voltage.This comparer produces one according to this first voltage and this second voltage and outputs signal to this output terminal.Wherein, when an environment temperature of this excess temperature detection circuit is higher than first temperature, this output signal that this comparer transition makes this comparer export is transformed into one second current potential by one first current potential.
Technical scheme in sum, whether excess temperature detection circuit of the present invention can detect the environment temperature overrun of particular element, and factor causes excess temperature phenomenon and burns because manufacture craft is bad etc. to avoid particular element.
Accompanying drawing explanation
Fig. 1 is the schematic diagram of the embodiment of the present invention one excess temperature detection circuit.
Fig. 2 is the schematic diagram of another excess temperature detection circuit of the embodiment of the present invention.
Fig. 3 is the schematic diagram of an equivalent electrical circuit of the excess temperature detection circuit of Fig. 2.
Fig. 4 A is the schematic diagram of the mode of operation of the excess temperature detection circuit of Fig. 2.
Fig. 4 B be the excess temperature detection circuit of Fig. 2 one output signal and an environment temperature to the schematic diagram of time variations.
Symbol description in figure:
10,20 excess temperature detection circuits
100 first bleeder circuits
102 second bleeder circuits
200 hysteresis circuitry
R1 ~ R4, R41, R5 resistance
RT thermistor
R2_eq, R4_eq equivalent electrical circuit
D diode
V1 first voltage
V2 second voltage
Vcc system voltage
Vout outputs signal
COMP comparer
GND earth terminal
N1, N2 node
V_H noble potential
V_L electronegative potential
T environment temperature
T1 first temperature
T2 second temperature
P1, p2 path
C1, c2 curve
T time variable
T1, t2 time
Embodiment
Please refer to Fig. 1, Fig. 1 is the schematic diagram of the embodiment of the present invention one excess temperature detection circuit 10.Excess temperature detection circuit 10 can detect the temperature whether overrun of a particular element 104, and it includes one first bleeder circuit 100,1 second bleeder circuit 102 and a comparer COMP.First bleeder circuit 100 comprises a resistance R1 ~ R2 and thermistor RT, and it can receive a system voltage Vcc, after the dividing potential drop by resistance R1 ~ R2 and thermistor RT, exports one first voltage V1 to comparer COMP via a node N1.Wherein, the resistance of thermistor RT changes according to temperature, and whether it is arranged at particular element 104 side, to detect the environment temperature T overrun of particular element 104.Second bleeder circuit 102 comprises resistance R3 ~ R4, R41, its acceptable system voltage vcc, after the dividing potential drop by resistance R3 ~ R4, R41, exports one second voltage V2 to comparer COMP via a node N2.After comparer COMP receives the first voltage V1 of the first bleeder circuit 100 output and the second voltage V2 of the second bleeder circuit 102 output by two (positive and negative) input end, first voltage V1 and the second voltage V2 is compared, and produces an output signal Vout.Specifically, when the first voltage V1 is greater than the second voltage V2, comparer COMP produces the output signal Vout with a noble potential V_H; Otherwise when the first voltage V1 is less than the second voltage V2, comparer COMP produces the output signal Vout with an electronegative potential V_L.Wherein, electronegative potential V_L can be the current potential of an earth terminal GND, but is not limited thereto, also visual actual design demand and changing according to this.
For ease of illustrating, in the present embodiment, the resistance of resistance R1 is identical with the resistance of resistance R3, and the resistance of resistance R2 is identical with the resistance of resistance R4, and the resistance of the resistance of resistance R1 ~ R4 much larger than thermistor RT and the resistance of resistance R41.In this case, the relative size of the first voltage V1 and the second voltage V2 can be considered the relative size of the resistance roughly depending on thermistor RT and resistance R41, namely, when the resistance of thermistor RT is less than the resistance of resistance R41, the first voltage V1 is less than the second voltage V2; When the resistance of thermistor RT is greater than the resistance of resistance R41, the first voltage V1 is greater than the second voltage V2.And in the present embodiment, the resistance of thermistor RT under room temperature environment is greater than the resistance of resistance R41, and thermistor RT is for having the thermistor of negative temperature coefficient (NegativeTemperatureCoefficient), namely the resistance of thermistor RT rises with temperature and reduces, but do not limit therewith, visual actual design demand and use the thermistor of positive temperature coefficient (PTC) yet.
By the thermistor RT of negative temperature coefficient; when the environment temperature T of excess temperature detection circuit 10 is higher than a first temperature T1; the resistance of thermistor RT declines and is less than the resistance of resistance R41; the first voltage V1 is made to be less than the second voltage V2; it is electronegative potential V_L that comparer COMP produces output signal Vout, starts over-temperature protection relevant action to indicate back-end circuit.
Be normal at the electric current flowing through particular element 104, when namely not starting over current protection protection mechanism, if the manufacture craft of particular element 104 is bad or because of other non-ideal factor, particular element 104 will be caused to produce high impedance and make its temperature still constantly raise.In this case, by excess temperature detection circuit 10, the present invention can detect environment temperature in advance, to indicate back-end circuit to start over-temperature protection action, as shutdown or the action such as to stop power supply.
It is noted that in this embodiment, if environment temperature T is by when changing into a little less than the first temperature T1 higher than the first temperature T1, the output signal Vout that excess temperature detection circuit 10 exports reverts to noble potential V_H at once.But, when environment temperature T is a little less than the first temperature T1, now environment temperature T is still close to fence coverage, if recovering output signal Vout is noble potential V_H, it is normal for showing now temperature, and user may start shooting once again at once, and at short notice environment temperature T likely once again more than the first temperature T1, therefore may cause start and close continually, be unfavorable for integrated circuit System Operation.In this case, buffering can be added further.
Please further refer to the schematic diagram that Fig. 2, Fig. 2 are the embodiment of the present invention one excess temperature detection circuit 20.Excess temperature detection circuit 20 and excess temperature detection circuit 10 similar, therefore similar elements is continued to use same-sign and is represented, compared to excess temperature detection circuit 10, excess temperature detection circuit 20 adds a hysteresis circuitry 200, between the positive input terminal being coupled to comparer COMP and output terminal, and include the resistance R5 and a diode D that are serially connected with a sequence.Running about hysteresis circuitry 200 can with further reference to Fig. 3, Fig. 3 for when outputing signal Vout and exporting as electronegative potential V_L, the schematic diagram of the equivalent electrical circuit between node N1, N2 of excess temperature detection circuit 20 and earth terminal GND.First, the output signal Vout produced as comparer COMP to drag down because temperature is too high and becomes electronegative potential V_L, and electronegative potential V_L is when being the current potential of earth terminal GND, can be considered and diode D is connected to earth terminal GND and conducting, now can be considered an equivalent electrical circuit R2_eq between node N1 and earth terminal GND, as shown in Figure 3.Equivalent electrical circuit R2_eq be resistance R2 be connected in series thermistor RT between node N1 and earth terminal GND after, then hysteresis circuitry in parallel 200 is between node N1 and earth terminal GND.Similarly, can be considered an equivalent electrical circuit R4_eq between node N2 and earth terminal GND.Because including the structure of hysteresis circuitry 200 in parallel in equivalent electrical circuit R2_eq, therefore thermistor RT need be greater than the specific resistance of resistance R41 mono-that the first voltage V1 just can be made to be greater than the second voltage V2.In other words, when environment temperature T drops to a second temperature T2 (the second temperature T2 is lower than the first temperature T1), make the first voltage V1 be greater than the second voltage V2, now comparer COMP produces output signal Vout and just reverts to noble potential V_H.
Specifically, the hysteresis effect that hysteresis circuitry 200 is reached can be the schematic diagram that embodiment of the present invention output signal Vout changes environment temperature T with reference to figure 4A, Fig. 4 A.In Figure 4 A, path p1 is environment temperature when increasing progressively, and the correspondence change path of output signal Vout, represents with solid line; Path p2 is environment temperature when successively decreasing, and the correspondence change path of output signal Vout, is represented by dotted lines.Under room temperature environment, the output signal Vout that comparer COMP produces is noble potential V_H.During when environment temperature T rising higher than the first temperature T1, comparer COMP transition is to export the output signal Vout of electronegative potential V_L, and variation pattern of its output signal Vout is as shown in the p1 of path.During until environment temperature T decline lower than the second temperature T2, comparer COM exports the output signal Vout of noble potential V_H, and variation pattern of its output signal Vout is as shown in the p2 of path.And output signal Vout and environment temperature T can with further reference to Fig. 4 B to the relation curve of time t.In figure 4b, curve c1 represents the relation curve of environment temperature T to time t, curve c2 represents that output signal Vout is to the relation curve of time t, as shown in curve c1, c2 in Fig. 4 B, same, when environment temperature T rises as during higher than the first temperature T1, the output signal Vout that comparer COMP exports becomes electronegative potential V_L by noble potential V_H transition, during until environment temperature T decline lower than the second temperature T2, the output signal Vout that comparer COMP exports just is able to be restored to noble potential V_H by electronegative potential V_L.The object of hysteresis circuitry 200 is to confirm that the temperature of particular element is with after being down to normal range, and just recovering to output signal Vout is noble potential V_H.
Therefore, except output signal Vout being dragged down as except electronegative potential V_L when temperature T is greater than the first temperature T1 around, excess temperature detection circuit 20 more utilizes hysteresis circuitry 200, after treating that environment temperature T is down to normal range (lower than the second temperature T2), just recovering output signal Vout is noble potential V_H.So can avoid switching on and shutting down continually, so as not to causing the more loss of circuit system.In addition, in hysteresis circuitry 200, diode D as switch element, but is not limited thereto, all can conducting when to output signal Vout be electronegative potential V_L, and the electronic component of closing all can be used for hysteresis circuitry 200 when to output signal Vout be noble potential V_H.In addition, the resistance of resistance R1 ~ R4, R41 is not limited to the above embodiments, and visual actual conditions change according to this or modify.
In sum, excess temperature detection circuit of the present invention is arranged near particular element, and whether to detect the environment temperature overrun of particular element, factor causes excess temperature phenomenon and burns because manufacture craft is bad etc. to avoid particular element.
The foregoing is only preferred embodiment of the present invention, all equalizations done according to the present patent application the scope of the claims change and modify, and all should belong to covering scope of the present invention.
Claims (7)
1. an excess temperature detection circuit, is characterized in that, this excess temperature detection circuit includes:
One first bleeder circuit, includes multiple resistance, is used for output one first voltage, and a resistance in described multiple resistance is thermistor;
One second bleeder circuit, includes multiple resistance, is used for output one second voltage; And
One comparer, includes:
One first input end, is coupled to the first bleeder circuit, is used for receiving this first voltage;
One second input end, is coupled to the second bleeder circuit, is used for receiving this second voltage; And
One output terminal, this comparer exports one according to this first voltage and this second voltage by this output terminal and outputs signal;
Wherein, when an environment temperature of this excess temperature detection circuit is higher than first temperature, this output signal that this comparer exports is transformed into one second current potential by one first current potential.
2. excess temperature detection circuit as claimed in claim 1, it is characterized in that, this excess temperature detection circuit also comprises a hysteresis circuitry, this hysteresis circuitry includes a first end and one second end, this first end of this hysteresis circuitry is coupled to this first input end of this comparer, and this second end of this hysteresis circuitry is coupled to this output terminal of this comparer.
3. excess temperature detection circuit as claimed in claim 2, it is characterized in that, this hysteresis circuitry includes a sluggish resistance and a switch element, and this sluggish resistance and this switch element are serially connected with a sequence.
4. excess temperature detection circuit as claimed in claim 3, it is characterized in that, when this environment temperature of this excess temperature detection circuit is higher than this first temperature, this first voltage is less than this second voltage, when this output signal of this comparer is this second current potential, this switching means conductive.
5. excess temperature detection circuit as claimed in claim 3, it is characterized in that, when this environment temperature of this excess temperature detection circuit is lower than second temperature, this first voltage is greater than this second voltage, this output signal of this comparer is this first current potential, and this switch element is closed.
6. excess temperature detection circuit as claimed in claim 5, it is characterized in that, this second temperature is lower than this first temperature.
7. excess temperature detection circuit as claimed in claim 3, it is characterized in that, this switch element is a diode.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| TW103122901 | 2014-07-02 | ||
| TW103122901A TWI511399B (en) | 2014-07-02 | 2014-07-02 | Over-temperature detection circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN105318984A true CN105318984A (en) | 2016-02-10 |
Family
ID=55246865
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201410344109.7A Pending CN105318984A (en) | 2014-07-02 | 2014-07-18 | Over-temperature detection circuit |
Country Status (2)
| Country | Link |
|---|---|
| CN (1) | CN105318984A (en) |
| TW (1) | TWI511399B (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107394746A (en) * | 2017-09-13 | 2017-11-24 | 广东美的暖通设备有限公司 | A kind of protection circuit with return difference |
| CN113884208A (en) * | 2021-09-09 | 2022-01-04 | 芯原微电子（成都）有限公司 | High-precision over-temperature detection circuit |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR3083307B1 (en) * | 2018-06-29 | 2021-09-24 | Sc2N Sa | TEMPERATURE SENSOR |
| CN111509961B (en) * | 2020-05-18 | 2022-08-30 | 广东美的暖通设备有限公司 | Over-temperature protection device, variable frequency driver, electrical appliance, method, device and storage medium |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH04132967A (en) * | 1990-09-25 | 1992-05-07 | Murata Mfg Co Ltd | Overheat protecting circuit |
| US20040042136A1 (en) * | 2002-09-04 | 2004-03-04 | Kuo Kuei Wei | Motor control device having temperature protection function |
| CN101165984A (en) * | 2006-10-20 | 2008-04-23 | 深圳安凯微电子技术有限公司 | Circuit for producing retarding window |
| CN201656433U (en) * | 2010-02-05 | 2010-11-24 | 国基电子（上海）有限公司 | Overheat protection circuit and electronic equipment using overheat protection circuit |
| CN103840434A (en) * | 2012-11-22 | 2014-06-04 | 广东美的制冷设备有限公司 | Over-temperature protection circuit used for power module |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| TWM391791U (en) * | 2010-04-01 | 2010-11-01 | Hon Hai Prec Ind Co Ltd | Overheating protection circuit and electronic device using the same |
| CN202167829U (en) * | 2011-08-18 | 2012-03-14 | 上海晨兴希姆通电子科技有限公司 | Over-temperature protection terminal controlled by hardware |
-
2014
- 2014-07-02 TW TW103122901A patent/TWI511399B/en active
- 2014-07-18 CN CN201410344109.7A patent/CN105318984A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH04132967A (en) * | 1990-09-25 | 1992-05-07 | Murata Mfg Co Ltd | Overheat protecting circuit |
| US20040042136A1 (en) * | 2002-09-04 | 2004-03-04 | Kuo Kuei Wei | Motor control device having temperature protection function |
| CN101165984A (en) * | 2006-10-20 | 2008-04-23 | 深圳安凯微电子技术有限公司 | Circuit for producing retarding window |
| CN201656433U (en) * | 2010-02-05 | 2010-11-24 | 国基电子（上海）有限公司 | Overheat protection circuit and electronic equipment using overheat protection circuit |
| CN103840434A (en) * | 2012-11-22 | 2014-06-04 | 广东美的制冷设备有限公司 | Over-temperature protection circuit used for power module |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107394746A (en) * | 2017-09-13 | 2017-11-24 | 广东美的暖通设备有限公司 | A kind of protection circuit with return difference |
| CN113884208A (en) * | 2021-09-09 | 2022-01-04 | 芯原微电子（成都）有限公司 | High-precision over-temperature detection circuit |
| CN113884208B (en) * | 2021-09-09 | 2023-10-10 | 芯原微电子（成都）有限公司 | High-precision over-temperature detection circuit |
Also Published As
| Publication number | Publication date |
|---|---|
| TWI511399B (en) | 2015-12-01 |
| TW201603427A (en) | 2016-01-16 |
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Application publication date: 20160210 |