TWI258008B - Temperature measurement circuit calibrated through shifting a conversion reference level - Google Patents

Abstract

A temperature measurement circuit has a current excitation circuit, a temperature calculation circuit, a calibration factor generator, and an analog-to-digital conversion circuit. The current excitation circuit supplies in sequence at least two currents to a thermal sensor from which are correspondingly generated at least two output signals. In response to the at least two output signals, the temperature calculation circuit calculates an analog temperature signal representative of a temperature detected by the thermal sensor. The analog-to-digital conversion circuit converts the analog temperature signal into a digital signal based on a conversion reference level. The conversion reference level is shifted in accordance with a calibration value generated from the calibration factor generator.

Description

1258008 IX. INSTRUCTIONS: [Technical field of invention] The present invention relates to a temperature production Jingping r喈屮5 slave / ',] circuit', especially regarding a positive function of a digital conversion ratio to a digital conversion circuit Measuring circuit. Replacing the rigid bit to achieve error correction [Prior Art] Due to the semiconductor between the semiconductor pole and the emitter of the diode element, the current between the two body elements is associated with each other and is a warm-production 'bit bang and flow through These semi-conductors are widely used in the field of road technology: a schematic diagram of the circuit configuration of the temperature measuring circuit 1 in the integrated body. The typical temperature 1 measuring circuit 10 is set to monitor the temperature of the external system. In the case of cattle, the external system and system 20 are - computers, electronic devices, or specific circuit areas, in which there is a thermal sensor 2 that can provide a semi-conductive surface to detect the degree of dislocation. As shown, the thermal sensor 21 is applied by a carrier transistor, and the semiconductor junction between the base and the emitter is used to detect temperature. In the temperature measuring circuit 1 ,, the switches & and S2 of the current source circuit u are controlled by the control circuit 12 to be turned on and off so as to allow different currents I and I2 to be applied to the thermal sensor 2 i, respectively. Assuming that the potential difference between the base and the emitter caused by the application of the current L to the thermal sensor 21 is Vbei and the potential difference between the base and the emitter caused by the current I2 applied to the thermal sensor 21 is calculated, the calculation circuit 13 After the potential difference Vbei and Vbe2 are subtracted from each other by 12580008, the following equation (1) can be obtained: ΔΥΒΕ = VBE1 - VBE2 = ^lniilL ^ .j/Re+^ (1)

-, 4 \l2 yv PJ where κ is the Bozmann (B〇ltzmann) constant, T is the absolute temperature, q is the basic electrical, Re is the series parasitic resistance of the emitter, and Rb is the series parasitic resistance of the base and β is the gain coefficient of the transistor. Therefore, the potential difference AVbe generated by the calculation of electricity, 3, can represent the analog signal of the temperature as a function of temperature. Subsequently, the analog to digital conversion circuit => nvmer, ADC) 14 converts such a specific temperature signal into a digital temperature equation (1), the series parasitic resistance of the thermal sensor 21 & The irrelevant constant term, that is, (η·#, is: shows the series parasitic resistance Re and ^ caused by ..., or a different kind of current, sequentially exciting the same 'in order to achieve accuracy The temperature measurement results. However, the use of two: = flow of the skill of the art to stimulate not only causes changes. Even in the case of unnecessary energy consumption and temperature 夂7 呆 呆 呆 频率 频率 频率 频率 频率 m m m m m m m m m Under the condition of exciting m ' 'the more different rings required \ : Inevitably extend each temperature measurement cycle: 1! And reduce the temperature measurement circuit 1. The reaction speed. Formed with heat "! The degree actually measured is the temperature of the substrate with the external system I, and the actual representative temperature of the external system 0 is not the same for this measurement. For example, ^20 is a computer. When I am interested, it is usually 12580008 =,] Boundary / System The temperature of the heat sink 22 of 20 is not the temperature of the semiconductor substrate on which the thermal sensor 21 is disposed. In this case, the external system 2 = manufacturer provides the substrate between the heat sink 22 and the thermal sensor 21 The temperature difference data ΔΤ is present so that the conventional temperature measuring circuit 10 stores it in the temporary storage state 15. Subsequently, the adding circuit i 6 compares the digital output of the analog to digital conversion circuit 14 with the register 15 The temperature difference data Δ dings are added to each other to generate a final temperature signal Tmp. SUMMARY OF THE INVENTION In view of the above-mentioned problems, it is an object of the present invention to provide a temperature measuring circuit that converts by shifting analog to digital conversion circuits. The error correction function is achieved by reference to the reference level. According to one of the present invention, a temperature measurement circuit is provided, which has a current excitation circuit, a calculation circuit, a correction value generation circuit, and an analog to digital conversion circuit. And applying at least two electrical signals, L to a thermal sensing, such that the thermal sensor correspondingly generates at least two output signals. In response to the at least two output signals The calculation circuit calculates a temperature signal representative of a temperature detected by the thermal sensor. The correction value generating circuit generates a correction value. The analog to digital conversion circuit compares the analog reference level according to a conversion reference level. The temperature signal is converted into a digital temperature signal. The conversion reference level is adjusted according to the correction value. * The thermal sensor has a semiconductor Pn junction such that the at least two current systems sequentially flow through the semiconductor pn junction And generating at least two potential differences respectively as the at least two output signals. The correction value is determined by 12580008: the stream excitation circuit sequentially applies at least three currents to the thermal sensor to make a difference The correction value is used to correct the constant temperature error of the analog temperature signal. The thermal sensor system is disposed in the substrate of the external system. The positive value of the technique is provided by the money system to correct the temperature detected by the thermal sensing crying and the representative temperature of the external system. A temperature measurement method is provided in accordance with another aspect of the present invention, and has a number of steps. First, at least two currents are sequentially applied to a thermal sensation: so that the thermal sensor correspondingly generates at least two output signals. Response: The two to: = out I signal:: Calculate an analog temperature signal, which represents the thermal sense set m to the temperature. Generate - correction value. The conversion-based analog temperature signal is converted into a digital temperature signal. The conversion multi-test level is adjusted in translation according to the correction value. According to another aspect of the present invention, a current excitation circuit is used for a thermal sensor. The lightning method/;, L> emitting circuit has a measuring current source, a positive current source circuit, a correction control circuit, and a measurement control circuit. Measuring the current source circuit ^ ^ 2 catch 1, the first one to measure the current and one second to measure the electricity k. Correct the current source. The circuit is supplied with a positive current. The correction control circuit allows the generator to measure the current, and the current is applied to the thermal sensor in sequence, and the correction current is sequentially applied to the thermal sensor. One of the detectors is often: = = ! The measurement control circuit allows the first-measurement current and the second amount, w right ^ ^ ..., sensed to measure the k-degree of the thermal sensor. The correction control circuit ^ ^ is activated earlier than the 1 test control circuit to measure the constant term error. 1258008 [Embodiment] The foregoing description of the present invention and other objects, features, and advantages of the present invention will be made more recent. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The preferred embodiments in accordance with the present invention will be described in detail with reference to the drawings. A diagram 2 is not based on the temperature measurement circuit of the present invention. The circuit configuration is shown in the /m degree measurement circuit 30. A current excitation circuit is a measurement current source circuit 3!, _ The current source circuit 3 2, a measurement control circuit 33, and a control circuit 34 are collectively constructed. The measuring current source circuit 31 has first and second measuring currents ... supplied to the emitter of the thermal sensor 21 via switches Si and s2, respectively. Correction current source power: 32 胄 父 父 positive current ", supplied to the thermal sensor two emitters via the switch & the temperature measurement electricity % 3 〇 start measuring the thermal sensor η 卜 degree $ 彳 again The positive clamping circuit 34 must be activated first to control the first and first 1 sense currents 11 and 12 and the correction current "sequentially applied to the thermal sensor 21. When the current is less than 11, and "the potential difference between the _ and the emitter caused by the thermal sensor 21 is VbE1, VBE2, and Vbe3, respectively, the difference circuit 35 can be calculated - the equation (2) Show: △Vbei = VBE1 - Vj κτ βε2 ~ —1ηq Ιι + (I “I2(Re 今κτ △mfln +(vURe +

Rb β β) (2) dAVBE = ΔνΒΕΙ - AVBE2 == in h_h. +(^-2I2-I3)iRe

^ V *-^2 JVRI It is assumed that the following ratio conditions (3) are satisfied between the currents Ii, and i3: 8 (3) 1258008 I] . I2 · I3 = A2 : A : 1 is the first measurement current Ii4 The second quantity measuring electric quantity two measuring current l2 is the correction current l3...: A times, and the equation (7) can be further advanced and simplified into the following;::: formula: zero, then (4) β dAVBE= (Al)2

Therefore, by correcting the current 1 gang 3 < special help, the difference circuit measures the constant term error dAVBE formed by the series parasitic resistance and also detects HAV &> /, b & Subsequently, the constant term difference (4) term M dAVBE is sent to the correction value generating circuit 36 for generating a positive value CF. In a preferred embodiment, the correction value CF is pre-determined before any temperature (4) cycle (4) to provide an error correction for the subsequent measurement cycle of the temperature measurement cycle. 3(A) to 3(C) show operational state diagrams of the calculation circuit 35 according to the present invention when detecting the constant term error dAVBE. In Figure 3 (A), the switch

Sa is turned on, switch Sb is turned on, switch Se is coupled to capacitor Cc to the non-inverting input terminal (+) of the differential amplifier AM, and the switch core couples capacitor Q to the inverting input terminal (-) of the differential amplifier AM. Furthermore, the switch s is turned on and the switches S2 and S3 are not turned on, so that only the first measurement current l is allowed to be applied to the thermal sensor 21 to generate a first potential difference vBE2 between the base and the emitter. In this first phase, since the voltages at the non-inverting input terminal (+) and the inverting input terminal (-) of the differential amplifier AM are both zero, the output voltage Vout(1) of the differential amplifier am is zero. In Fig. 3(B), both switches sa and Sb become non-conductive. In addition, the switch S2 is turned on and the switches S! and S3 are not turned on, so that the current difference I is applied to the first potential difference VBE2 between the emitters of the thermal sensing cry 2 1 . In this second phase... ° The non-inverting input (+) and the inverting input and the moving amplifier of the AM are both (VBE1-VBE2)/2, so the differential amplifier AM Take out the tailu soil, (Vbe〗-VBE2). In Fig. 3(C), the switch becomes such that the capacitance θ c DUi = is the inverting input terminal of the differential amplification l § AM, and to the old man, the name l, the factory section 1 ~ accepts the capacitor d light a to 1 non-inverting input terminal (+) of the mobile amplifier AM. S3 is turned off and M Sl# 82 is not turned on, so only correction power is allowed: "Apply to the thermal sensor 21 to generate the base The second between the pole and the emitter + 2 ^ : two In this third phase, the differential amplifier ΑΜ < output power;;,) again ... (vbe1-vBE2) - (VbE2_VbE3), that is, the desired detection The constant term error dAVBE of the equation and (4). Please note that the correction current source circuit U 盥 in accordance with the present invention corrects 杵 = path 34 after the completion of the aforementioned constant term error (4) program ^ turns out to the correction value generating circuit 36, i.e., stops the operation. In other words, during the temperature measurement cycle, the temperature measurement circuit 3 〇 only uses the measurement control 33 to measure the current source circuit 31 to sequentially apply the first and second measurements, then y 1 /, 12 to heat Sensor 2 1. Therefore, the operational state of the calculation circuit 35 in the temperature amount cycle is limited to Figs. 3(A) and 3(B). In the case where the ratio j d is satisfied and the constant term error dAVBE of the equation (4) is obtained, the potential difference Δν 间 between the base and the emitter obtained by the leaf circuit 35 can be expressed as follows: ΔΥ, be

Vbei-VBE2 KT q 1η(Α)+ί-~^ΔΥΒΕ (5) 10 l258〇〇8 According to the present invention, the potential difference Λν σ - obtained by the first disk is measured, and the current is measured by the summer. The ratio of 丨 to mvbe disk is adjusted by a constant term error column as long as M is translated: 乘 (A_1) product can generate the correct temperature amount. Since this constant term error ~ has been assisted by the correction of electricity, ώ 3 Detected and stored in the claws per temperature measurement in the loop and then re-detected / path, so it is not necessary to be in addition to the constant term error Μ, the school can receive the external Lee correction and correct the circuit 36 Also, the 22-way, ... is related to the thermal sensor 21 and the heat sink difference: the difference data... Since the constant term error and the temperature "data ΔΤ are all errors that can be translated, the correction value generating circuit 36 It can be integrated into a single correction value CF. Based on the correction value CF, the shift correction analog to digital conversion circuit 37 determines the appropriate conversion reference vertical map. FIG. 4 does not according to the present invention, the translation correction analog to digital conversion The principle of the knowledge of the second road is not intended. In a broad sense, The analog-to-digital conversion circuit 37 converts the received analog signal into a 'according to a predetermined sampling frequency'. The analog result obtained by sampling after P-pass is mathematically regarded as 缍 converted to a digital corresponding to #Dx. The digital signal, wherein the actual value of the digital signal depends on the relative position of the conversion reference level REF. For example, as shown in FIG. 4, the original conversion reference level REF is translated downward by a positive value CF. Forming a translated conversion reference quasi 4 REF — S For the original conversion reference level REF, the analog sample AS is converted into a digital signal DgU. For the translated reference reference level REF_S and s, the analog sample AS is Converted into a digital signal. Therefore, by translationally converting the reference level Ref, the translation correction analog analog 11 1258008 to the digital conversion circuit 37 can effectively perform constant term error and temperature during the analog to digital conversion process. Correction of the difference data AT to obtain a correct temperature measurement result without additional conventional addition procedure. FIG. 5 shows an analog to digital conversion according to the present invention. A detailed circuit diagram of an example of the circuit 37. The sampling/modulation circuit 5 i is based on the clock signal CLK provided by the clock generator 52 for the potential between the base φ and the emitter from the calculation circuit 35. Line sampling, and the sampling result is adjusted into a pulse sequence signal. For example, the sampling/modulation circuit 5 is implemented by a Delta-Sigma analog to digital modulator, and thus the pulse sequence signal is analogous to the sample. The corresponding digital signal is applied to the counter 53 from the sampling/modulation circuit 5. The counter 53 counts the number of pulses in the received pulse sequence signal for a predetermined period. Since the number of (4) 1 53 is counted up from a count reference value, the effect of shifting the count reference value is equivalent to the count result calculated by the flat shift adjustment counter 53, so the inventor will This technique was originally applied to the constant error correction of the 6 temperature measurement results. Specifically, the [counter 53 <counting reference value is determined by the correction value CF supplied from the correction value generating circuit 36 in the correction value generating circuit ^, and the constant term error (10) from the calculating circuit 35 is multiplied by the multiplier 41. The upper scale factor ΜΑ·1) is then summed with the temperature difference data 从 from the external system 20 via the addition H 42 to synthesize the desired single-correction value CF and stored in the correction register 43 . In other words, the embodiment of Fig. 5 does not aim to achieve the translation conversion reference level ref of Fig. 4 by shifting the value of the counter reference 12 1258008 of the counter μ. The other side of the frequency divider 54 divides the clock signal CLK of the clock generator 52 to produce a lower frequency reset signal RST. In one embodiment, the frequency of the weight a and the number RST generated by the frequency band of two kilograms is obtained by dividing the frequency of the clock generator 52 by the frequency of CLK by 1〇24. Therefore, after the clock signal CLK 匕 1024 cycles, the counter 53 is reset to the count reference value and the count is restarted. Similarly, this count reference value is determined by the correction value CF supplied from the correction value generating circuit 36. In addition, the result of the counter 53 counting in the 24 cycles of the clock signal is transmitted to the output temporary memory crying V^θ', the mouth 5, and is taken as the "1" measurement result Tmp. external. This temperature is measured by the frequency of the reset signal RST, and the Tmp is also updated according to the frequency of the reset signal RST. The present invention has been described by way of illustration of the preferred embodiments. It is understood that the invention is not limited to the disclosed embodiments. Rather, the invention is intended to cover various modifications and similarities to the skilled in the art. Therefore, the scope of the scope of the patent application should be based on the interpretation of the above (4) to accommodate all such modifications and similar configurations. [Simple description of the diagram] Figure 1: Schematic diagram of the circuit configuration of the temperature measurement circuit of Baizhi. ^ ',,,, schematic diagram of the circuit configuration of the temperature measuring circuit according to the present invention. 3(A) to 3(c) are diagrams showing the operational state of the calculation circuit in accordance with the present invention. 13 1258008 Figure 4 is a diagram showing the principle of operation of a translation correction type analog to digital conversion circuit in accordance with the present invention. Figure 5 shows a detailed circuit diagram of one of the analog to digital conversion circuits in accordance with the present invention.

[Main component symbol description] 10 Temperature measurement circuit 11 Current source circuit 12 Control circuit 13 Calculation circuit 14 Analog to digital conversion circuit (ADC) 15 Register 16 Addition circuit 20 External system 21 Thermal sensor 22 Heat sink 30 Temperature Measurement circuit 31 Measurement current source circuit 32 Correction current source circuit 33 Measurement control circuit 34 Correction control circuit 35 Calculation circuit 36 Correction value generation circuit 37 Translation correction analog to digital conversion circuit (ADC) 14 1258008 41 Multiplier 42 addition 43 Correction register 5 1 Sampling/modulation circuit 52 Clock generator 53 Counter 54 Frequency divider

55 Output Register AM Differential Amplifier

Ca~Cd Capacitor CF Correction Value CLK Clock Signal I 1, I 2 Measurement Current 13 Correction Current

Rb, Re series parasitic resistance RST reset signal

Sl5 S2, S3, Sa ~Sd switch

Tmp temperature measurement result V b E Potential difference between base and emitter dAVBE constant term error ΔΤ temperature difference data 15

Claims (1)

1258008 X. Patent Application Range·· 1 · A temperature measurement circuit, including ··································································· Correspondingly generating at least two output signals; a calculation circuit for calculating a ratio /jel degree 彳1 2 in response to the at least two output signals, which represents a temperature detected by the thermal sensor a correction value generating circuit 'for generating a correction value; and a turn ratio to digital conversion circuit for converting the analog value to a digital temperature signal according to a conversion reference level, wherein the conversion reference level The adjustment is shifted according to the correction value. 2. The temperature measuring circuit of claim 1, wherein: the thermal sensor has a semiconductor pn junction, such that the at least two current systems sequentially flow through the semiconductor pn junction and are respectively generated thereon At least two potential differences are used as the at least two output signals. 3. The temperature measuring circuit of claim 1, wherein: the correction value is calculated by sequentially applying at least three motors to the thermal sensor by the current excitation circuit, so that the correction value is obtained. Used to correct the constant term error of one of the analog temperature signals. 16 1 · The temperature measurement circuit of item 3 of the patent scope of the application, wherein: 2 the error of the 4 items is caused by the resistance of at least one series parasitic electric energy of the thermal sensor of 125808, such as the patent application scope ^. Staff's dish measurement circuit, a &amp; μ thermal sensor system is set in one, ^ Bu 'I system one of the substrates, Gan, chaotic edge correction value is defeated by the outside world π π 予 , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , Λ 之一 之一 之一 之一 之一 之一 之一 之一 之一 之一 之一 之一 之一 之一 之一 之一 之一 之一 之一 之一 之一 之一 之一 之一 之一 之一 之一 之一 之一 之一 之一 之一 之一 之一 之一 之一 之一 之一 之一 之一 之一 之一 之一 如 之一 如 如 如The first quantity, the Ρ丨丨雷, the six ife, the second measurement current; The circuit is configured to allow the first measurement current and the thermal sensor to be slightly earlier than the measurement control circuit, as part of the correction value or a full correction current source, a circuit-correction control circuit The second measuring current, the correcting electric quantity and the measuring quantity control electric brother, a measuring current is sequentially applied to the correction control electric motor to calculate a constant item error part. </ RTI> to provide a correction current; to allow the first measurement current, the flow is sequentially applied to the thermal sensor; For example, in the patent application scope, the first measurement current is the second measurement current of the tributary temperature measurement circuit, which is t A times, and the first measurement current of 17 1258008 is one times the correction current, wherein A is greater than zero. 8. The temperature measuring circuit of claim 1, wherein: the analog to digital conversion circuit comprises: a sampling/modulation circuit that generates a pulse sequence signal in response to the analog temperature signal, and a counter Responding to the pulse sequence signal to generate a count result in a / predetermined period, which represents the number of pulses of the pulse sequence signal, wherein the count result is incremented from a reference value, and the reference value is determined by the The correction value is set. 9) A temperature measurement method, comprising: sequentially applying at least two currents to a thermal sensor, such that the thermal sensor correspondingly generates at least two output signals; Calculating an analog temperature signal in response to the at least two output signals, which represents a temperature detected by the thermal sensor; generating a correction value; and converting the analog temperature signal according to a conversion reference level And forming a digital temperature signal, wherein the conversion reference level is adjusted in translation according to the correction value. The temperature measuring method of claim 9, wherein: the thermal sensor has a semiconductor pn junction such that the at least two 18 1258008 currents sequentially flow through the semiconductor pn junction At least two 甩 差 ' respectively are generated as the at least two rounding signals. η. For the temperature measurement method of the ninth patent range, wherein: &gt; μ edge correction value is calculated by sequentially applying three currents to the thermal sensor, so that the correction value is used for correction This analog is one of the constant errors of the temperature signal. For example, the temperature measurement method of the t/month patent range 帛11 item, wherein: the number of errors is caused by at least one series parasitic resistance of the thermal sensor. 13. If the patent application scope is item 9, the thermal sensor is set in one The positive value of the fork is provided by the external system, and the temperature detected by the device is different from that of the external system. And a temperature measuring method, wherein: a thermal sensor in a substrate of the external system and correcting the thermal sensing between a representative temperature, comprising: a first measuring current and a 14th current exciting circuit For exciting one-way current source circuit for providing one or two measurement currents; - correcting current source circuit for providing a correction current; positive control circuit for allowing the first measurement current, the first Second, the current is measured, and the correction current is sequentially applied to the thermal sensor, and the quantity 19 19258008 is related to the constant term error of the thermal sensor; and the θ "test control circuit is used to allow the current." The first measuring current and the second measuring current are sequentially applied to the thermal sensor, thereby measuring the temperature of one of the thermal sensors, wherein the positive control circuit is more than the measuring control circuit It is activated early to measure the error of the constant term. Such as Shen. The current excitation circuit of item i of the monthly patent range, wherein: _ the thermal detector has a semi-conducting 胄 junction, such that the first measurement package 'the first measurement current, and the correction current Any one of the currents lacks the semiconductor pn junction to create a potential difference thereon. Where: The series parasitic electricity 16 · The current excitation circuit of the 14th patent range of the patent section is caused by at least one resistance of the thermal sensor. 17. The first measurement current is the current excitation circuit of the school, wherein: the first current measurement circuit is A times, and the positive current is A times. Where a is greater than zero Q. For example, the current excitation circuit of the patent ^ 1 - 呗, in the measurement control circuit is activated to perform the temperature, and the correction control circuit stops the operation. After 4, the 20