1235231 玖、發明說明： 【發明所屬之技術領域】 本發明係關於一種電流模式溫度偵測電路及方法 、 指一種適用於計算電流流量以進行溫度偵 法，尤 法。 又1貝甽之電路及方 【先前技術】 10 15 ::裝置運作時’因消耗能量而.產生熱能，如果敎能 未月匕及日守排除，則電子裝置可能因為過熱而產生益 ^錯誤，故使用溫度細路並配合熱敏電阻之運作，、以 監視電子裝置之表面、、4里 古 在置之表面/皿度，如果電子裝置之表面溫度過 則溫度谓測電路將驅動風扇或散熱器之運作 電子裝置之表面溫度。由於習知 電阻因溫度變化而造成„:心度蝴路係細敏 面溫度，然而此方法=:::判斷電子裝置之表 使用者對溫度偵測之需:出之溫度較不精準，無法滿足 晶體之射極與基極之間係為_pN介面，因此， ::=山與基射電厂堅Vbe(基極與射極之電麼差)之間 /、有下列方程式之關係： vRf, IE=Isxe^ 其中’ VT又可以表示成下列方程式：1235231 发明 Description of the invention: [Technical field to which the invention belongs] The present invention relates to a current mode temperature detection circuit and method, and refers to a method, especially method, suitable for calculating current flow for temperature detection. Another circuit and method of Beckham [Previous Technology] 10 15 :: When the device is operating, 'due to energy consumption. Thermal energy is generated. If the energy is not removed and the day guard is eliminated, the electronic device may generate benefits due to overheating ^ Error Therefore, the use of a temperature shunt and the operation of a thermistor to monitor the surface of the electronic device, and the surface / plate degree of the 4 Liguo, if the surface temperature of the electronic device is too high, the temperature measuring circuit will drive the fan or The surface temperature of the electronic device in which the heat sink operates. Because the conventional resistance is caused by temperature changes, „: heart rate butterfly system is the sensitive surface temperature, but this method = ::: to determine the needs of users of electronic devices for temperature detection: the temperature is less accurate and cannot be It is satisfied that the emitter and base of the crystal is a _pN interface. Therefore, :: = Mountain and the base Vbe (the difference between the base and the emitter) has the following equation: vRf , IE = Isxe ^ where 'VT can be expressed as the following equation:
vT^EL ，T q (2； 當中’丁為待測物表面 對，皿度（早位為0K )，如果以 20 1235231 攝氏溫度表示時’則將絕對溫度加上273 &vT ^ EL, T q (2; where ′ is the surface pair of the object to be measured, the degree of the dish (the early position is 0K), if expressed in 20 1235231 Celsius temperature, ”the absolute temperature is added 273 &
測物表面之攝氏溫度（單位為。c)。為了消除不必2 = 數，故量測二個具有倍數差之射極電流Ie，故能取得 之值，再依據下列方程式計算： BE 5The temperature in Celsius on the surface of the object (unit: c). In order to eliminate the need of 2 = number, so measure two emitter currents Ie with multiple difference, so the value can be obtained, and then calculate according to the following equation: BE 5
^VBE =77X KT I --χ In— q I ei^ VBE = 77X KT I --χ In-- q I ei
由於方程式（3)中、“理想參數）、“單位 ，子之電量Ί (波次曼常數）、及射極電流Iei與射極電 机Ια之比例為已知，故能得知待測物表面之絕對溫度。 10 15 由方私式（1 )、⑺、及（3 )中可得知，如果能量測 基射電壓ΔνΒΕ之值時，即能間接得知待測物之溫度。習 头1度偵/則電路中亦有利用電流流量，流經電晶體後以取 ^待測物之溫度，如美國專利第5,982,221號，專利名稱 Switched current temperature sensor circuit with ⑶mP〇unded ΛνΒΕ」，如圖i所示，其使用一放大器以放 大正/負輸入端之電壓差，而輸出放大之AVbe，再藉由方 程j (3)即能得知待測物之溫度。由於習知係間接藉由放 大裔（類比）2倍壓，以取得2,倍的AVbe，但因切換式電 路的開關雜戒會造成2〃x △ Vbe有所偏差而較不精綠，這將 無法滿足使用者對溫度精確控制上之需求。 【發明内容】 20 1235231 本發明之主要目的係在提供一種電流模式溫度偵測 電路，俾能藉由量測電流之變化而有效地取得待測物之溫 度0 為達成上述目的，本發明揭露一種電流模式溫度偵測 5電路，其包括··第一電流源，係用以提供倍數電流；第二 電流源，係用以提供單位電流，倍數電流之大小係為單位 電μ之倍數，多工器，係依據第一切換訊號而輸出倍數電 二，單位龟々IL，感應态，係用以輸入倍數電流以提供第一 10 電壓或輸入單位電流以提供第二電壓；高精準切換放大 用以依據第一切換訊號而放大第一電壓及基礎電壓 之：壓差：放大基礎電壓及第二電壓之電壓差，並輸出： 出電壓，第一取樣電路，係用以調整基礎電壓之電壓準位， 使輸出電壓之電壓準位能近似參考電壓；以及第二取樣電 路，係用以依據第二切換訊號以量化 15儲存至記憶體。 I肝…果 H弛万式】 審查委Μ能更瞭解本發明之技術内容，牟 牛 乂 4土八月豆貫施例說明如下。 上述方程式⑴、⑺、及（3)， 電流模式溫度偵測電路2〇可用以旦、ρ丨丨+日 ^不 △vBE，如此_來，^^用以里測電晶體10之基射電！ 兩曰遍 卩犯侍知待測物之溫度。者缺，卜μ μ 龟日日體10需放置於待 田…、此日1 ,^ ^之表面、底面、或内涂私佐、日丨w 中，較佳係内建於待測物巾。U · Μ建於待測物 ’電晶體10亦可被二桮 20 1235231 體（thermal diode)所取代，此時，方程式（ι )與（2 中之基射電壓VBE需以二極體之壓降（ν〇)取代。 本發明電流模式溫度偵測電路2〇包括下列元件：一第 一電流源22、一第二電流源24、一多工哭％ 丄μ σσ 夕丄态26、一切換放大 ίο 15 器（switch amplifier) 28、一 第一取樣電路3〇 (包括·一 比較器32、一控制器34、及一數位_類比轉換器36)、第二 取樣電路40 (包括：一比較器42、一控制器44、及一數位_ 類比轉換器46)、及一記憶體50。其中，第一電流源^與 第二電流源24所提供之電流量係相差n倍，例如：第一電 流源22提供ΙΟΟμΑ ( 1〇*〇之電流量，第二電流源24提供 1〇μΑ (I)之電流量。切換放大器28之放大倍數為Α。數位 -類比轉換器36及數位-類比轉換器46較佳係為逐次漸近型 暫存器（Successive Approximation Register，SAR)之類 比轉換器，假設其工作電壓係為1 ·6伏特，如此一來，其預 設輸出電壓可為0_8伏特，即基礎電壓Vbase之初始值可為 0.8伏特。如圖3所示，切換放大器28 (或切換放大器36) 内部組設有一多工器281及一放大器282，如此一來，即能 依切換訊號之電壓準位而改變輸入訊號之輸入路徑。例 如，當切換訊號為低電壓準位時，多工器281係為去能，正 輸入端所輸入之訊號係輸出之放大器282之正輸入端，負輸 入端所輸入之訊號係輸出之放大器282之負輸入端；當切換 訊號為高電壓準位時，多工器2 81係為致能，正輸入端所輸 入之訊號係輸出之放大器282之負輸入端，負輸入端所輸入 之訊號係輸出之放大器282之正輸入端。 20 1235231 、，首先，令參考電壓vREF為一固定值，假設為16伏特， 亚令第一切換訊號ISW為低電壓準位，使第一電流源22所 提供之電流量1〇〇μΑ可流入電晶體10，使電晶體1〇之基極 與射極間產生第一基射電壓VBE1，並提供第一基射電壓 5 Vbe丨至切換放大器28之正輪入端。假設基射電壓VBE丨為 0.625伏特，因為基礎電壓乂^5£為〇8伏特，所以切換放大 器28之輸出電壓乂01為_5伏特（極值），並將輸出電壓ν〇ι 輸出至第一取樣電路30,再由第一取樣電路3〇調整基礎電 壓Vbase之電壓準位，使輸出電壓v〇1之電壓準位能逼近參 10 考電壓VREF之電壓準位。 / 第一取樣電路30之運作如下所述。由於基射電壓 之電壓低於基礎電壓Vbase，所以比較器32輸出低準位之2 較輸出訊號CMP1至控制器34,控制器34依據比較輸出訊號 CMP1之準位而控制數位_類比轉換器36之運作，使其輸出 15不同電壓準位之基礎電壓VBASE。數位-類比轉換器36•，其 可為逐次漸近暫存器（Successive Approximati〇nSince the "ideal parameters", "units", "units", and the ratio of the emitter current Iei to the emitter motor Iα in equation (3) are known, the object to be measured can be known The absolute temperature of the surface. 10 15 It can be known from the square private formulas (1), ⑺, and (3) that if the energy measures the value of the fundamental emission voltage ΔνΒΕ, the temperature of the object to be measured can be indirectly known. Xitou ’s 1-degree detection circuit also uses current flow to pass through the transistor to obtain the temperature of the test object, such as US Patent No. 5,982,221, patent name Switched current temperature sensor circuit with ⑶mP〇unded ΛνΒΕ ", As shown in Fig. I, it uses an amplifier to amplify the voltage difference between the positive and negative input terminals, and outputs the amplified AVbe, and then the temperature of the object to be measured can be obtained by the equation j (3). As the conventional system indirectly gains 2 times the AVbe by amplifying the 2 times the voltage (analog), but the switching ring of the switching circuit will cause 2〃x △ Vbe to be biased and less refined. This will Can not meet the user's needs for precise temperature control. [Summary of the invention] 20 1235231 The main purpose of the present invention is to provide a current mode temperature detection circuit, which can effectively obtain the temperature of the object to be measured by measuring the change in current. To achieve the above purpose, the present invention discloses a Current mode temperature detection 5 circuit, which includes a first current source to provide multiple currents; a second current source to provide unit current, the size of the multiple current is a multiple of the unit electricity μ, multiplexing The device is based on the first switching signal and outputs multiples of electric two, unit IL, inductive state, and is used to input multiple currents to provide the first 10 voltage or input unit current to provide the second voltage; high-precision switching amplification is used to Amplify the first voltage and the base voltage according to the first switching signal: Voltage difference: Amplify the voltage difference between the base voltage and the second voltage and output: Output voltage, the first sampling circuit is used to adjust the voltage level of the base voltage , So that the voltage level of the output voltage can be approximated to the reference voltage; and a second sampling circuit is used to quantify 15 stored in the memory according to the second switching signalLiver I ... Fruits Hundreds] The review committee can understand the technical content of the present invention better. The example of Mou Niu Dai 4 Tu August Dou Guan is described below. In the above equations ⑴, ⑺, and (3), the current-mode temperature detection circuit 20 can be used for denier, ρ 丨 丨 + day ^ no △ vBE, so _ come, ^^ is used to measure the base 10 of the transistor 10 radio! Two times, the offender knows the temperature of the object to be measured. However, the μ μ turtle sun body 10 needs to be placed on the field ..., the surface, bottom surface, or inner coating of the day, ^ ^ on this day, preferably built in the towel to be measured . U · M built on the object to be measured. The transistor 10 can also be replaced by a two-cup 20 1235231 body (thermal diode). At this time, the base emission voltage VBE in equations (ι) and (2 needs to be the voltage of the diode. The current-mode temperature detection circuit 20 of the present invention includes the following components: a first current source 22, a second current source 24, a multiplexing crying state 丄 μ σσ evening state 26, a switch Amplifier ο 15 switch amplifier 28, a first sampling circuit 30 (including a comparator 32, a controller 34, and a digital-to-analog converter 36), a second sampling circuit 40 (including: a comparison Device 42, a controller 44, and a digital-to-analog converter 46), and a memory 50. Among them, the amount of current provided by the first current source ^ and the second current source 24 is n times different, for example: the first One current source 22 provides a current amount of 100 μA (10 * 〇), and the second current source 24 provides a current amount of 10 μA (I). The amplification factor of the switching amplifier 28 is A. Digital-to-analog converter 36 and digital-to-analog The converter 46 is preferably a Successive Approximation Register (SAR) The analog converter assumes that its operating voltage is 1.6 volts. In this way, its preset output voltage can be 0-8 volts, that is, the initial value of the base voltage Vbase can be 0.8 volts. As shown in Figure 3, the switching amplifier 28 (Or switching amplifier 36) The internal group is provided with a multiplexer 281 and an amplifier 282. In this way, the input signal input path can be changed according to the voltage level of the switching signal. For example, when the switching signal is a low voltage level When the bit is set, the multiplexer 281 is disabled, the signal input from the positive input terminal is the positive input terminal of the output amplifier 282, and the signal input from the negative input terminal is the negative input terminal of the output amplifier 282. When the switching signal is At the high voltage level, the multiplexer 2 81 is enabled. The signal input from the positive input terminal is the negative input terminal of the output amplifier 282, and the signal input from the negative input terminal is the positive input terminal of the output amplifier 282. 20 1235231 First, let the reference voltage vREF be a fixed value, assuming 16 volts, and let the first switching signal ISW be a low voltage level, so that the amount of current provided by the first current source 22 can be 100 μA. The crystal 10 causes a first base-emitter voltage VBE1 to be generated between the base and the emitter of the transistor 10, and provides a first base-emitter voltage 5 Vbe 丨 to the input of the positive wheel of the switching amplifier 28. Assume that the base-emitter voltage VBE 丨 is 0.625 volts, because the base voltage 乂 ^ 5 £ is 〇8 volts, so the output voltage 乂 01 of the switching amplifier 28 is _5 volts (extreme value), and the output voltage ν〇ι is output to the first sampling circuit 30, and then by The first sampling circuit 30 adjusts the voltage level of the base voltage Vbase so that the voltage level of the output voltage v01 can approach the voltage level of the reference voltage VREF. / The operation of the first sampling circuit 30 is as follows. Since the voltage of the base emission voltage is lower than the base voltage Vbase, the comparator 32 outputs a lower level of 2 than the output signal CMP1 to the controller 34. The controller 34 controls the digital according to the level of the comparison output signal CMP1_analog converter 36 Its operation makes it output the base voltage VBASE of 15 different voltage levels. Digital-to-Analog Converter 36 •, which can be a Successive Asymptotic Register (Successive Approximati〇n
Register，SAR)型或其他類型之類比轉換器，並配合比較 器32及控制器34之運作而具有二元搜索樹（binary search tree)之功能，並經過數次迴圈（較佳為1〇次）比較後， 20即能得到適當之基礎電壓VBASE，並使下列方程式成立： BEX ^〇Sl ) _ ^BASE ] X ^ = V( 4 ) 偏移電壓V〇S1為切換放大器28所具有之偏移電壓。此 10次迴圈之結果如下表所示： I23523lRegister (SAR) or other types of analog converters, with the function of the comparator 32 and the controller 34, has a binary search tree function, and has gone through several loops (preferably 10). After the comparison, the appropriate base voltage VBASE can be obtained at 20, and the following equation can be established: BEX ^ 〇Sl) _ BASE] X ^ = V (4) The offset voltage V0S1 is what the switching amplifier 28 has. Offset voltage. The results of these 10 cycles are shown in the following table: I23523l
0.59375 次迴圈“，基礎ΐ壓 此時方程式（4)之計算結果為1.6171875伏特，接近參考 電壓Vref。經10次迴圈後，控制器34棒止對數位_類比轉換 器36之控制，使基礎電壓Vbase之電壓準位保持不變，使輸 出電壓V01之電壓準位亦保持不變。由上述中可知，第一 取樣電路30可使輸出電壓V〇1之電壓準位能逼近參考電壓 vref之電壓準位。 10 當輸出電壓V01之電壓準位保持不變後，再由第二取 樣電路40量化（數位化）輸出電壓v〇1之電壓準位。其中， 第二取樣電路40之運作與第一取樣電路3〇之運作相似，第 一比較态42、第一控制器44、及第二數位_類比轉換器牝 之組合亦具有：元搜索樹（binaryse㈣心〇之功能，故 能量化輸出電壓V01所對應之電壓值。首先，+第二切換 訊號CSW為低電塵準&，朗數次迴圈比較| ,第二控制 器44依據第二比較器42之比較輸出訊號cMp2而控制第二 數位-類比轉換器46之運作，使第二數位·類比轉換器46之 輸出電壓V02的電壓準p_ • 电土 +位將可逐漸逼近輸出電壓V01的電 Μ準位’即能得到輸出雷屨v 、 ® ^&V〇1所對應之第一電壓值DV01 (假设為1 ·60伏特），並將第一帝 昂 电壓值储存至記憶體50 〇 15 1235231 由於第二比較器42具有偏移電壓v〇S2，所以第一電壓值 DV01可由下列方程式表示： DVOl = [(VBEl ~ v〇S{) ^ VmE ]χΑ_^ ( 5) 之後，令第二切換訊號CSW為高電壓準位，經過數次 5迴圈比較後，即能得到輸出電壓V01所對應之第二電壓值 DV02(假設為1.62伏特），並將第二電壓值儲存至記憶體 50。第二電壓值DV02可由下列方程式表示： DV02 = [(VBE{ - V0SI) ~ vbase ]xA + V0S2 · ( 6) 當完成第一基射電壓Vbei之量測後，令第一切換訊號 0 10 ISW為高電壓準位，使第二電流源24所提供之電流量ι〇μΑ 可流入電晶體10，以使電晶體10產生第二基射電壓; 並致能多工器281，以改變輸入訊號之輸入路徑，以進行第 二基射電壓VBE2之量測。假設基射電壓¥邮2為〇57伏特， 並輸入至放大器282之負輸入端，而基礎電壓Vbase為 15 〇·5890625伏特（保持不變），並輸入至放大器282之正輸 入端，故切換放大器28之輸出電壓¥〇1經a倍放大後假設 為0.8578125伏特，接著，由第二取樣電路4〇進行上述量化 鲁 處理後。首先，令第一切換訊號csw為低電壓準位，經過 數次迴圈比較後，即能得到輸出電壓v〇丨所對應之第三電 20壓值0¥03 (假設為〇·8伏特），並儲存至記憶體5〇。第三 電壓值DV03可由下列方程式表示： DV03 = [iyBASE + V0Sl) - VBE2 ] X ^ - y〇s2 ( 7 ) 然後，令第一切換訊號CSW為高電壓準位，經過數次 迴圈比較後，即能得到輸出電壓V01所對應之第四電壓值 11 1235231 DV04 (假設為0.9伏特），並儲存至記憶體％。第四電壓 值DV04可由下列方程式表示： DV〇4 = [(VBASE + V0Sl)-VBE2]x^ + ( 8) 最後，將方程式（5)、⑷、⑺、及⑴相加， 5即可得到2*Α*ΔνΒΕ之結果，再將此結果除以2八，故能得 知ΔνΒΕ之值’再藉由方程式⑴即能得知待測物之絕對 而舉例而已，本發明所 圍所述為準，而非僅限0.59375 cycles ", the calculation result of equation (4) at this moment is 1.6171875 volts, which is close to the reference voltage Vref. After 10 cycles, the controller 34 stops the logarithmic _ analog converter 36 to control The voltage level of the base voltage Vbase remains unchanged, so that the voltage level of the output voltage V01 also remains unchanged. As can be seen from the above, the first sampling circuit 30 can make the voltage level of the output voltage V〇1 approach the reference voltage vref 10 After the voltage level of the output voltage V01 remains unchanged, the second sampling circuit 40 quantizes (digitizes) the voltage level of the output voltage v〇1. Among them, the operation of the second sampling circuit 40 Similar to the operation of the first sampling circuit 30, the combination of the first comparison state 42, the first controller 44, and the second digital_analog converter 牝 also has the function of a binary search tree (binaryse ㈣ heart 〇, so energy The voltage value corresponding to the output voltage V01. First, the + second switching signal CSW is a low electric dust level & a few times of loop comparison |, the second controller 44 is based on the comparison output signal cMp2 of the second comparator 42 and Controlling the second digit -The operation of the analog converter 46 makes the voltage level p_ of the output voltage V02 of the second digital analog converter 46 • The electric earth + bit will gradually approach the electric level V of the output voltage V01, and the output voltage 屦 v can be obtained. , ® ^ & V〇1 corresponds to the first voltage value DV01 (assuming 1.60 volts), and stores the first Diang voltage value in the memory 50 〇15 1235231 because the second comparator 42 has an offset The voltage v0S2, so the first voltage value DV01 can be represented by the following equation: DVOl = [(VBEl ~ v〇S {) ^ VmE] χΑ_ ^ (5) After the second switching signal CSW is set to a high voltage level, After 5 times of comparison, the second voltage value DV02 (assuming 1.62 volts) corresponding to the output voltage V01 can be obtained, and the second voltage value is stored in the memory 50. The second voltage value DV02 can be expressed by the following equation ： DV02 = [(VBE {-V0SI) ~ vbase] xA + V0S2 · (6) After the measurement of the first base shot voltage Vbei is completed, make the first switching signal 0 10 ISW to the high voltage level and make the second The amount of current provided by the current source 24 μA can flow into the transistor 10, so that the transistor 10 generates a second And enable the multiplexer 281 to change the input path of the input signal for the measurement of the second base radio voltage VBE2. Assume that the base radio voltage ¥ 2 is 057 volts and input to the negative of the amplifier 282 Input terminal, and the base voltage Vbase is 15 0.58990625 volts (which remains unchanged), and is input to the positive input terminal of the amplifier 282, so the output voltage of the switching amplifier 28 ¥ 〇1 is amplified by a factor of 0.8578125 volts, then After the above-mentioned quantization processing is performed by the second sampling circuit 40. First, the first switching signal csw is set to a low voltage level. After several rounds of comparison, the third voltage 20 corresponding to the output voltage v〇 丨 can be obtained 0 ¥ 03 (assuming 0.8V). And save it to memory 50. The third voltage value DV03 can be expressed by the following equation: DV03 = [iyBASE + V0Sl)-VBE2] X ^-y〇s2 (7) Then, the first switching signal CSW is set to a high voltage level. After several loop comparisons, That is, the fourth voltage value 11 1235231 DV04 (assuming 0.9 volts) corresponding to the output voltage V01 can be obtained and stored in the memory%. The fourth voltage value DV04 can be expressed by the following equation: DV〇4 = [(VBASE + V0Sl) -VBE2] x ^ + (8) Finally, add equation (5), ⑷, ⑺, and ⑴ to get 5 The result of 2 * Α * ΔνΒΕ, and then divide this result by 2 eight, so we can know the value of ΔνΒΕ 'and then use equation ⑴ to know the absolute value of the object to be tested. For example, what is described in the present invention is Standards, not just
上述實施例僅係為了方便說明 主張之權利範圍自應以申請專利範 10 於上述貫施例。 【圖式簡單說明】 圖1係習知溫度偵測電路之示意圖。 圖2係本發明電流模式溫度偵測電路之示意圖。 圖3係切換放大器之示意圖。 ^The above-mentioned embodiments are merely for the convenience of explanation. The scope of the claimed right should be applied to the above-mentioned embodiments by applying for a patent scope. [Schematic description] Figure 1 is a schematic diagram of a conventional temperature detection circuit. FIG. 2 is a schematic diagram of a current mode temperature detection circuit according to the present invention. Figure 3 is a schematic diagram of a switching amplifier. ^
【圖號說明】 20 電流模式溫度彳貞測電 路 26 多工器 28 切換放大器 32 比較器 34 控制 器 器40 第二取樣電路 42 比較 器 46 數位-類比轉換器 50 記憶 體 282 放大器 22 第一 電流源 10電晶體 24苐一電流源 30第一取樣電路 36數位-類比轉換 44控制器 281多工器 12[Illustration of the drawing number] 20 Current mode temperature measurement circuit 26 Multiplexer 28 Switching amplifier 32 Comparator 34 Controller 40 Second sampling circuit 42 Comparator 46 Digital-to-analog converter 50 Memory 282 Amplifier 22 First current Source 10 transistor 24 current source 30 first sampling circuit 36 digital-analog conversion 44 controller 281 multiplexer 12