CN204142381U - Temperature measuring circuit - Google Patents
Temperature measuring circuit Download PDFInfo
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- CN204142381U CN204142381U CN201420638771.9U CN201420638771U CN204142381U CN 204142381 U CN204142381 U CN 204142381U CN 201420638771 U CN201420638771 U CN 201420638771U CN 204142381 U CN204142381 U CN 204142381U
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- Prior art keywords
- voltage
- oxide
- metal
- temperature
- temperature measuring
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- 239000004065 semiconductor Substances 0.000 claims abstract description 31
- 230000036413 temperature sense Effects 0.000 claims abstract description 15
- 238000006243 chemical reaction Methods 0.000 claims description 17
- 238000000034 method Methods 0.000 claims description 7
- 238000012545 processing Methods 0.000 claims description 7
- 238000001914 filtration Methods 0.000 claims description 5
- 230000010354 integration Effects 0.000 description 4
- 238000005070 sampling Methods 0.000 description 2
- 238000009529 body temperature measurement Methods 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 230000003750 conditioning effect Effects 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 238000000605 extraction Methods 0.000 description 1
- 238000011545 laboratory measurement Methods 0.000 description 1
- 238000013507 mapping Methods 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
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Abstract
The utility model provides a kind of temperature measuring circuit, comprise temperature sense circuit, it exports the first and second voltages characterizing temperature variation, and described temperature sense circuit comprises: bias current sources, and it comprises the first and second output terminals exporting the first and second electric currents respectively; First and second metal-oxide-semiconductors, all be configured to grid be connected and ground connection with drain electrode, the source electrode of described first metal-oxide-semiconductor connects described first output terminal, the source electrode of described second metal-oxide-semiconductor connects described second output terminal, wherein, described first voltage is the difference of the gate source voltage of described first and second metal-oxide-semiconductors, and described second voltage is the gate source voltage of the described first or second metal-oxide-semiconductor.Temperature measuring circuit of the present utility model is applicable on sheet integrated, and has the feature of low power consumption high-precision, can be applicable to the chip circuitry of low supply voltage.
Description
Technical field
The utility model relates to a kind of temperature measuring circuit.
Background technology
At present, the market development of environmental monitoring, medical device and high-precision electronic device, proposes low-power consumption, high precision, requirement easy of integration to temperature measurement schemes.For obtaining accurate temperature value, conventional scheme uses high-accuracy temperature measuring device, but this method is not easy of integration, is only applicable to the occasions such as laboratory measurement, can not be applicable to utilize RFID label tag to gather the emerging fields such as environment temperature.
Prior art, such as, in patent documentation CN102435336A, discloses and is applicable to temperature measuring circuit integrated on sheet, is all to utilize conventional temperature-sensing element triode to carry out temperature survey, but its supply voltage required is higher, does not utilize system power dissipation.In addition, in prior art, the A/D conversion accuracy of temperature measuring circuit is too low, can not meet the demand of existing market.
Utility model content
For this reason, the utility model provides a kind of temperature measuring circuit, comprises temperature sense circuit, and it exports the first and second voltages characterizing temperature variation, described temperature sense circuit comprises: bias current sources, and it comprises the first and second output terminals exporting the first and second electric currents respectively; First and second metal-oxide-semiconductors, all be configured to grid be connected and ground connection with drain electrode, the source electrode of described first metal-oxide-semiconductor connects described first output terminal, the source electrode of described second metal-oxide-semiconductor connects described second output terminal, wherein, described first voltage is the gate source voltage of the described first or second metal-oxide-semiconductor, and described second voltage is the difference of the gate source voltage of described first and second metal-oxide-semiconductors.
Further, described temperature measuring circuit also comprises analog to digital conversion circuit, for the analog quantity of the ratio representing described first voltage and the second voltage is converted into bit stream, analog-digital conversion circuit as described comprises SAR ADC and Sigma-Delta modulator, wherein, described SAR ADC transforms the integral part of described analog quantity, and described Sigma-Delta modulator transforms the fraction part of described analog quantity.
Further, described temperature measuring circuit also comprises digital processing circuit, carries out filtering and extract process to obtain measured temperature value and to store this temperature value to described bit stream.
Preferably, described first and second metal-oxide-semiconductors are PMOS.
Preferably, described first electric current is 5 ~ 10 times of described second electric current.
Preferably, described digital processing circuit comprises sinc
3digital filter is to carry out described filtering and to extract process.
Temperature measuring circuit of the present utility model is applicable on sheet integrated, and utilizes the characteristic of diode connecting-type metal-oxide-semiconductor to produce the voltage signal with temperature correlation, and it has the feature of low-power consumption, can be applicable to the chip circuitry of low supply voltage; Utilize SAR ADC to combine with Sigma-Delta modulator and carry out analog to digital conversion, existing market desired level can be reached.
Accompanying drawing explanation
Fig. 1 is the composition frame chart of temperature measuring circuit of the present utility model;
Fig. 2 is the schematic diagram of an embodiment of temperature measuring circuit of the present utility model.
Embodiment
Below in conjunction with the drawings and specific embodiments, temperature measuring circuit of the present utility model is described in further detail, but not as to restriction of the present utility model.
With reference to Fig. 1, it is the composition frame chart of temperature measuring circuit of the present utility model.In the architecture, temperature measuring circuit comprises temperature sense circuit 100, analog to digital conversion circuit 200 and digital processing circuit 300.
Wherein, temperature sense circuit 100 is for exporting the first voltage V characterizing temperature variation
1with the second voltage V
2.This temperature sense circuit 100 comprises bias current sources 110, and it has output first electric current I
1the first output terminal, and output second electric current I
2the second output terminal.Temperature sense circuit 100 also comprises the first metal-oxide-semiconductor M
1with the second metal-oxide-semiconductor M
2, be all configured to diode connecting-type, i.e. two metal-oxide-semiconductor M
1and M
2grid be connected and ground connection with drain electrode, and, the first metal-oxide-semiconductor M
1source electrode connect the first output terminal, namely receive the first electric current I
1, the second metal-oxide-semiconductor M
2source electrode connect the second output terminal, namely receive the second electric current I
2.The first voltage V that temperature sense circuit 100 exports
1be the first metal-oxide-semiconductor M
1gate source voltage V
gS1or the second metal-oxide-semiconductor M
2gate source voltage V
gS2, its second voltage V exported
2for M
1and M
2the difference of gate source voltage, i.e. Δ V as shown in Figure 2
gS.
As shown in Figure 2, the first metal-oxide-semiconductor M
1with the second metal-oxide-semiconductor M
2be preferably PMOS, the first electric current I
1it is the second electric current I
2m doubly, be preferably 5 ~ 10 times.Thus, temperature sense circuit 100 PMOS of the diode connecting-type be biased under different current density, responds to extraneous temperature, can obtain the first voltage V
1, i.e. negative temperature coefficient voltage V
gS(V
gS1or V
gS2), by changing the first electric current I
1with the second electric current I
2electric current ratio, the second voltage V can be regulated
2, i.e. positive temperature coefficient (PTC) voltage Δ V
gS, more just can carry out temperature survey by subsequent conditioning circuit.
Due to the gate source voltage V of metal-oxide-semiconductor under normal temperature
gSapproximate 0.3V, and the base emitter voltage V of the temperature-sensing element triode of routine
bEapproximate 0.7V, visible, the V of metal-oxide-semiconductor
gSthan the V of triode
bEmuch lower, under therefore it can be operated in lower supply voltage.Compared with prior art, this temperature sense circuit 100 utilizes metal-oxide-semiconductor to carry out temperature-sensitive, while simplification circuit design, reduces the power consumption of system.Meanwhile, under it can be operated in lower supply voltage, therefore, its range of application is wider.
The the first voltage V exported by temperature sense circuit 100
1(i.e. negative temperature coefficient voltage V
gS) and the second voltage V
2(i.e. positive temperature coefficient (PTC) voltage Δ V
gS) obtain measured temperature value principles illustrated as follows.By positive temperature coefficient (PTC) voltage Δ V
gSwith negative temperature coefficient voltage V
gS, may be combined with into zero-temperature coefficient voltage V
rEF.And zero-temperature coefficient voltage V
rEF=V
gS+ α Δ V
gS, wherein, α is constant, value 14 ~ 18.
Then, the positively related coefficient r with temperature can be obtained according to following formula (1):
Wherein, α is a constant, and value is 14 ~ 18,
for the first voltage V that temperature sense circuit 100 exports
1(i.e. negative temperature coefficient voltage V
gS) and the second voltage V
2(i.e. positive temperature coefficient (PTC) voltage Δ V
gS) ratio.
Finally, determine the principle of straight line according to two points, the mapping relations of the positively related coefficient r to temperature value Temp with temperature can be obtained, that is:
Temp=A*r-B, formula (2)
Wherein, A=580 ~ 620, B=260 ~ 280.
In order to improve the first voltage V
1with the second voltage V
2the digitized precision of ratio, temperature measuring circuit of the present utility model also comprises analog to digital conversion circuit 200, for the analog quantity of the voltage signal comprising temperature information is converted into the bit stream that data bit width is 1 bit.Wherein, the analog quantity comprising the voltage signal of temperature information is the first voltage V
1with the second voltage V
2ratio, i.e. negative temperature coefficient voltage V
gSwith positive temperature coefficient (PTC) voltage Δ V
gSratio
To analog quantity
when carrying out digitizing, integral part and fraction part are changed respectively.Analog quantity can be decomposed, that is:
Wherein n is integral part, and μ is fraction part.
Analog to digital conversion circuit 200 comprises SAR (successive approximation register type) ADC (analog-digital converter) 210 and Sigma-Delta modulator 220, wherein, the integral part n of described SAR ADC 210 converts analog amount, described Sigma-Delta modulator 220 transforms the fraction part μ of described analog quantity.
With reference to Fig. 2, the analog-digital conversion process of analog to digital conversion circuit 200 is described.
First, thick conversion is completed, by V with SAR ADC (being preferably the SAR ADC of 5 bits) 210
gSwith the Δ V of integral multiple
gSmake comparisons, thus obtain integral part n, and store in a register.
Then, Sigma-Delta modulator 220 completes essence conversion, namely when comparer exports the first state (such as exporting is 1), and Sigma-Delta modulator 220 integration V
gS-(n+1) Δ V
gS, when comparer exports the second state (such as exporting is 0), integration V
gS-n Δ V
gS.After work a period of time, according to principle of charge conservation, that is:
(1-μ) (V
gS-n Δ V
gS)+u (V
gS-(n+1) Δ V
gS)=0, formula (4)
The value of fraction part can be obtained according to following formula (5):
Wherein, integral part n is converted to by SAR ADC 210.
Thus, analog to digital conversion circuit 200 obtains
integral part n and the digitized value of fraction part μ, namely obtain
outputted to digital processing circuit 300.Digital processing circuit 300 comprises sinc
3digital filter, the bit stream for 1 bit exported by analog to digital conversion circuit 200 carries out extraction and filtering process, becomes digital signal, and the bit wide of this digital signal can need to select according to precision, and such as, selecting data bit wide is 12 bits.Namely the data of this 12 bit can to obtain in formula (1) and (2) the positively related coefficient r with temperature divided by 4096, thus obtain the temperature value Temp that will measure.This temperature value Temp obtained can store in memory, and directly can be read by digital communication interface by external entity.
The analog to digital conversion circuit 200 of temperature measuring circuit of the present utility model, adopts the framework that SAR ADC210 combines with Sigma-Delta modulator 220, forms at a high speed and high-precision analog to digital converter.Due to integer and fraction part are quantized respectively, ensureing to quantize high-precision while, the accuracy requirement of Sigma-Delta modulator 220 is reduced (such as, do not need to adopt the double precision Sigma-Delta modulator disclosed in patent documentation CN102435336A, can reach the precise digitization higher than the document yet).Owing to reducing the accuracy requirement of Sigma-Delta modulator 220, namely its over-sampling rate does not need too high, and therefore its working time shortens greatly, thus reduces the average power consumption of system; The demand of amplifier output voltage swing and sampling capacitance is also reduced simultaneously, system power dissipation can be reduced further.
Temperature measuring circuit of the present utility model is applicable on sheet integrated, and utilizes the characteristic of diode connecting-type metal-oxide-semiconductor to produce the voltage signal with temperature correlation, and it has the feature of low-power consumption, can be applicable to the chip circuitry of low supply voltage; Utilize SAR ADC to combine with Sigma-Delta modulator and carry out analog to digital conversion, existing market desired level can be reached.
Above embodiment is only illustrative embodiments of the present utility model, can not be used for limiting the utility model, and protection domain of the present utility model is defined by the claims.Those skilled in the art can in essence of the present utility model and protection domain, and make various amendment or equivalent replacement to the utility model, these are revised or be equal to replacement and also should be considered as dropping in protection domain of the present utility model.
Claims (6)
1. a temperature measuring circuit, comprises temperature sense circuit, and it exports the first and second voltages characterizing temperature variation, and described temperature sense circuit comprises:
Bias current sources, it comprises the first and second output terminals exporting the first and second electric currents respectively;
First and second metal-oxide-semiconductors, are all configured to grid and are connected and ground connection with drain electrode, and the source electrode of described first metal-oxide-semiconductor connects described first output terminal, and the source electrode of described second metal-oxide-semiconductor connects described second output terminal, wherein,
Described first voltage is the gate source voltage of the described first or second metal-oxide-semiconductor, and described second voltage is the difference of the gate source voltage of described first and second metal-oxide-semiconductors.
2. temperature measuring circuit according to claim 1, it is characterized in that, described temperature measuring circuit also comprises analog to digital conversion circuit, for the analog quantity of the ratio representing described first voltage and the second voltage is converted into bit stream, analog-digital conversion circuit as described comprises SAR ADC and Sigma-Delta modulator, wherein, described SAR ADC transforms the integral part of described analog quantity, and described Sigma-Delta modulator transforms the fraction part of described analog quantity.
3. temperature measuring circuit according to claim 2, is characterized in that, described temperature measuring circuit also comprises digital processing circuit, carries out filtering and extract process to obtain measured temperature value and to store this temperature value to described bit stream.
4. temperature measuring circuit according to claim 1, is characterized in that, described first and second metal-oxide-semiconductors are PMOS.
5. temperature measuring circuit according to claim 1, is characterized in that, described first electric current is 5 ~ 10 times of described second electric current.
6. temperature measuring circuit according to claim 3, is characterized in that, described digital processing circuit comprises sin c
3digital filter is to carry out described filtering and to extract process.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420638771.9U CN204142381U (en) | 2014-10-29 | 2014-10-29 | Temperature measuring circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420638771.9U CN204142381U (en) | 2014-10-29 | 2014-10-29 | Temperature measuring circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN204142381U true CN204142381U (en) | 2015-02-04 |
Family
ID=52419061
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201420638771.9U Expired - Lifetime CN204142381U (en) | 2014-10-29 | 2014-10-29 | Temperature measuring circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN204142381U (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104639168A (en) * | 2015-02-15 | 2015-05-20 | 芯原微电子(上海)有限公司 | Sigma-Delta type analog-to-digital converter analog front end circuit |
| CN105606239A (en) * | 2014-10-29 | 2016-05-25 | 上海贝岭股份有限公司 | Temperature measurement circuit |
| CN107923800A (en) * | 2015-09-25 | 2018-04-17 | 英特尔公司 | Heat sensor including non-inverting input |
| CN108981940A (en) * | 2018-10-08 | 2018-12-11 | 长江存储科技有限责任公司 | A kind of temperature sensor |
| CN109459156A (en) * | 2018-09-13 | 2019-03-12 | 中国地震局地壳应力研究所 | Ultradeep well High Precision Temperature Measuring Instruments |
| CN110307912A (en) * | 2018-03-20 | 2019-10-08 | 合肥格易集成电路有限公司 | A kind of temperature sensing circuit and method |
-
2014
- 2014-10-29 CN CN201420638771.9U patent/CN204142381U/en not_active Expired - Lifetime
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105606239A (en) * | 2014-10-29 | 2016-05-25 | 上海贝岭股份有限公司 | Temperature measurement circuit |
| CN104639168A (en) * | 2015-02-15 | 2015-05-20 | 芯原微电子(上海)有限公司 | Sigma-Delta type analog-to-digital converter analog front end circuit |
| CN104639168B (en) * | 2015-02-15 | 2017-11-10 | 芯原微电子(上海)有限公司 | Sigma Delta type analog-to-digital converter analog front circuits |
| CN107923800A (en) * | 2015-09-25 | 2018-04-17 | 英特尔公司 | Heat sensor including non-inverting input |
| US10866145B2 (en) | 2015-09-25 | 2020-12-15 | Intel IP Corporation | Thermal sensor including pulse-width modulation output |
| CN110307912A (en) * | 2018-03-20 | 2019-10-08 | 合肥格易集成电路有限公司 | A kind of temperature sensing circuit and method |
| CN109459156A (en) * | 2018-09-13 | 2019-03-12 | 中国地震局地壳应力研究所 | Ultradeep well High Precision Temperature Measuring Instruments |
| CN108981940A (en) * | 2018-10-08 | 2018-12-11 | 长江存储科技有限责任公司 | A kind of temperature sensor |
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Legal Events
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|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CX01 | Expiry of patent term |
Granted publication date: 20150204 |