CN112816088A - Self-adaptive range switching temperature sensor - Google Patents

Self-adaptive range switching temperature sensor Download PDF

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CN112816088A
CN112816088A CN202110036726.0A CN202110036726A CN112816088A CN 112816088 A CN112816088 A CN 112816088A CN 202110036726 A CN202110036726 A CN 202110036726A CN 112816088 A CN112816088 A CN 112816088A
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CN112816088B (en
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毕见鹏
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Beijing Microchip Blockchain And Edge Computing Research Institute
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Beijing Microchip Blockchain And Edge Computing Research Institute
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01K—MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
    • G01K7/00—Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements
    • G01K7/01—Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements using semiconducting elements having PN junctions
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02D—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE
    • Y02D10/00—Energy efficient computing, e.g. low power processors, power management or thermal management

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Abstract

The invention provides a self-adaptive range switching temperature sensor, which comprises: the current generating circuit is used for generating a measuring current according to the temperature to be measured; the range switching circuit is used for converting the measurement current according to the bit flow control signal and the range control vector signal to generate a conversion current; the modulator circuit is used for carrying out analog-to-digital modulation on the conversion current to generate a bit stream signal; the counter circuit is used for receiving the bit stream signal, generating a binary signal according to the duty ratio information of the bit stream signal, and outputting a measurement result of the temperature to be measured according to the binary signal; the range control circuit is used for generating a range control vector signal according to the binary signal. According to the invention, by carrying out refinement and splitting on a large temperature measurement range interval and matching with a corresponding modulator circuit and a range control circuit, the range of the temperature sensor has the function of automatic refinement and switching, a high-precision range matched with the current measured temperature is automatically searched, and high-precision measurement is realized.

Description

Self-adaptive range switching temperature sensor
Technical Field
The invention relates to the technical field of electronic circuits, in particular to a self-adaptive range switching temperature sensor.
Background
The temperature sensor, especially the on-chip temperature sensor, is widely applied to various chip internal designs because of its high integration level, and its basic working principle is: the current inversely proportional to absolute temperature and the current proportional to absolute temperature are generated through a triode and an operational amplifier, the two currents are combined and operated, then the charge and discharge of a capacitor are realized through an integrator, the charge and discharge voltage passes through a comparator, a bit stream signal containing temperature information is generated, the duty ratio of the bit stream signal is proportional to the temperature, and then the bit stream signal which can be sampled and quantized by a digital signal is output after the clock synchronization of a digital domain.
The conventional temperature sensor combines the proportional current and the inverse current according to the following principle: the temperature variation range (temperature measurement range) is corresponding to the whole duty ratio range as much as possible, if the temperature variation range (temperature measurement range) is not full of the temperature variation range, the duty ratio range is low in utilization rate, the quantization digit is fixed, the accuracy required by unit stepping is high, and the design requirement of minimum accuracy cannot be finally realized due to mismatch. In addition, in practical design, in order to avoid process deviation and sampling errors, certain margins are reserved at the positions with the maximum duty ratio and the minimum duty ratio, and only the middle duty ratio range of 80% -90% is used, so that the precision requirement becomes higher, and the realization is more difficult.
Case 1: the traditional temperature sensor with fixed range, for example, the range is-40 to 125 ℃, during actual design, the temperature range is mapped to the whole duty ratio range, and a temperature precision (called precision 1) is correspondingly obtained, if the temperature sensor with fixed range is applied to a scene with a small temperature range, for example, 20 to 50 ℃, because the actual duty ratio change range only occupies about one fifth of the design range, about four fifth of the range is wasted, and only the measurement precision of precision 1 can be realized, so the measurement precision often cannot meet the actual requirement.
Case 2: if the design range of the temperature sensor with the same voltage and the same number of bits is changed to 20-50 ℃, the relatively small temperature range can be mapped to the whole duty ratio range during design, and because the duty ratio range is fixed, a relatively higher and more easily realized measurement accuracy (called accuracy 2) can be obtained in the small temperature range, but the temperature sensor is limited to measure a larger temperature range.
In the two cases, different designs need to be made for different measuring objects and different applications, and different batches of tape-out are performed, so that the manpower resource of the design is wasted, and the tape-out cost is increased.
Disclosure of Invention
Aiming at the problems in the prior art, the embodiment of the invention provides the self-adaptive range switching temperature sensor, which improves the automation and the self-adaptive degree of temperature measurement of the temperature sensor, reduces the operation complexity and can effectively improve the measurement precision.
The invention provides a self-adaptive range switching temperature sensor, which comprises: the device comprises a current generating circuit, a range switching circuit, a modulator circuit, a counter circuit and a range control circuit; the current generating circuit is used for generating measuring current according to the temperature to be measured; the range switching circuit is used for converting the measurement current according to the bit flow control signal and the range control vector signal to generate a conversion current; the modulator circuit is used for carrying out analog-to-digital modulation on the conversion current to generate a bit stream signal; the counter circuit is used for receiving the bit stream signal, generating a binary signal according to the duty ratio information of the bit stream signal and outputting a measurement result of the temperature to be measured according to the binary signal; and the range control circuit is used for generating the range control vector signal according to the binary signal.
According to the adaptive span switching temperature sensor provided by the present invention, in a case where the measurement current includes a first current and a second current different from the first current, the span switching circuit includes:
the current mirror circuit comprises a first current mirror group consisting of m parallel current mirrors and a second current mirror group consisting of n parallel current mirrors, wherein each current mirror is connected with a summing node through an independent switch; the first current is connected to the parallel intersection point of the first current mirror group, and the second current is connected to the parallel intersection point of the second current mirror group; the summing node is connected to an input of the modulator circuit.
According to the self-adaptive range switching temperature sensor provided by the invention, the range control circuit at least comprises a range control scheme storage module so as to store a plurality of range control schemes in advance; each measuring range control scheme is a scheme for controlling the switching state of each current mirror according to different measuring ranges; and on the basis of the temperature measurement sequence corresponding to the range of each range control scheme, each range control scheme corresponds to different range control gears in sequence.
The adaptive range switching temperature sensor provided by the invention is characterized in that the range control circuit generates the range control vector signal according to the binary signal, and the adaptive range switching temperature sensor specifically comprises: the measuring range control circuit acquires binary data in the binary signal; under the condition that all the binary data are determined to be 0, generating a range downshift control vector signal; under the condition that all the binary data are determined to be 1, generating a range upshift control vector signal; the range downshift control vector signal is a signal related to a range control scheme corresponding to the next range control gear, which is called from the range control scheme storage module; the range upshift control vector signal is a signal related to the range control scheme corresponding to the previous range control gear, which is called from the range control scheme storage module.
According to the adaptive range switching temperature sensor provided by the invention, the range control circuit generates the range control vector signal according to the binary signal, and the adaptive range switching temperature sensor further comprises: the range control circuit judges whether the temperature corresponding to the binary signal is within a preset range of the current range under the condition that the binary data are not all 0 and not all 1; and if the current range is not within the preset range, generating a range downshift control vector signal.
According to the self-adaptive range switching temperature sensor provided by the invention, the first current mirror group at least comprises a first current mirror with a mirror proportion size of 1, the second current mirror group at least comprises a second current mirror with a mirror proportion size of 1, and switches corresponding to the first current mirror and the second current mirror are normally closed; the first current mirror group at least comprises a third current mirror with the mirror image proportion size of 1, and the second current mirror group at least comprises a fourth current mirror with the mirror image proportion size of 1; the bit stream control signal is used for controlling switches corresponding to the third current mirror and the fourth current mirror; the measuring range control vector signal is used for controlling switches corresponding to other current mirrors except the first current mirror, the second current mirror, the third current mirror and the fourth current mirror.
According to the self-adaptive range switching temperature sensor provided by the invention, m parallel current mirrors forming the first current mirror group are all PMOS transistors; the n parallel current mirrors forming the second current mirror group are all NMOS transistors; the grid electrode of each PMOS transistor is connected in parallel and is connected with the mirror voltage of the ground current mirror corresponding to the first current; the source stage of each PMOS transistor is connected in parallel and grounded; the drain of each PMOS transistor is respectively connected with one end of a switch, and the other end of each switch is connected in parallel and is connected into the summing node; correspondingly, the grid electrode of each NMOS transistor is connected in parallel and is connected with the mirror image voltage of the ground current mirror corresponding to the second current; the source stage of each NMOS transistor is connected in parallel and grounded; and the drain of each NMOS transistor is respectively connected with one end of a switch, and the other end of each switch is connected in parallel and is connected into the summing node.
According to the adaptive range switching temperature sensor provided by the invention, the current generation circuit comprises: first PNP triode, second PNP transistor, first resistance, second resistance, third resistance, fourth resistance, first fortune is put, second electric capacity, fourth PMOS transistor, fifth PMOS transistor, sixth PMOS transistor, fourth NMOS transistor, fifth NMOS transistor, sixth NMOS transistor, wherein: the base stage of the first PNP triode is connected with the collector electrode of the first PNP triode, the base stage of the second PNP triode, the collector electrode of the second PNP triode, one end of the second capacitor, the source electrode of the fifth NMOS transistor and one end of the fourth resistor, and is connected with the ground; an emitter of the first PNP triode is connected to one end of the first resistor and the positive input end of the first operational amplifier; the negative input end of the first operational amplifier is connected with one end of the second resistor and one end of the third resistor; the output end of the first operational amplifier is connected with the grid electrode of the fourth NMOS transistor; the source of the fourth NMOS transistor is connected with the other end of the first resistor, the other end of the second resistor and the other end of the second capacitor; the drain of the fourth NMOS transistor is connected with the drain of the fourth PMOS transistor, the grid of the fourth PMOS transistor and the grid of the fifth PMOS transistor; the source electrode of the fourth NMOS transistor is connected with the source electrode of the fifth PMOS transistor, the source electrode of the sixth PMOS transistor and a power supply; the drain of the fifth PMOS transistor is connected with the drain of the fifth NMOS transistor and the grid of the fifth NMOS transistor and outputs the first current; the grid electrode of the sixth PMOS transistor is connected with the drain electrode of the sixth PMOS transistor and the drain electrode of the sixth NMOS transistor and outputs the second current; the grid electrode of the sixth PMOS transistor is connected with the output end of the second operational amplifier; the source of the sixth PMOS transistor is connected with the other end of the fourth resistor and the negative input end of the second operational amplifier; and the positive input end of the second operational amplifier is connected with the emitter of the second PNP triode and the other end of the third resistor.
According to the present invention, there is provided an adaptive range switching temperature sensor, the modulator circuit comprising: the first capacitor, the third operational amplifier, the comparator and the synchronous circuit; the third operational amplifier and the first capacitor form an integrating circuit, one end of the first capacitor is connected with the negative input end of the third operational amplifier, the other end of the first capacitor is connected with the output end of the third operational amplifier and the negative input end of the comparator, and the positive input end of the third operational amplifier is connected with an integrating reference voltage corresponding to the measuring current; the positive input end of the comparator is connected with the threshold voltage of the comparator; the output end of the comparator is connected with the synchronous circuit, and the synchronous circuit is used for generating the bit stream signal according to the comparison result output by the comparator in the system clock period.
According to the adaptive range switching temperature sensor provided by the invention, the counter circuit comprises: the device comprises a counting module, a timing module and an output indicating module; the counting module is used for receiving the bit stream signal and quantizing the duty ratio information in the bit stream signal so as to output binary data corresponding to the measurement result of the temperature to be measured; the timing module is used for controlling the time period for converting the measuring current and controlling the counting duration of the counting module; the output indication module is used for resetting the counting module and the timing module after the measuring result is output.
The self-adaptive range switching temperature sensor provided by the invention has the advantages that the large temperature measurement range interval is refined and split, and the corresponding modulator circuit and the range control circuit are matched, so that the range of the temperature sensor has the function of automatic refined switching, the high-precision range matched with the current measured temperature is automatically searched, and the high-precision measurement is realized.
Drawings
In order to more clearly illustrate the technical solutions of the present invention or the prior art, the drawings needed for the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and those skilled in the art can also obtain other drawings according to the drawings without creative efforts.
FIG. 1 is a schematic structural diagram of an adaptive range switching temperature sensor according to the present invention;
FIG. 2 is a schematic diagram of a prior art temperature sensor;
FIG. 3 is a schematic structural diagram of a manual range switching temperature sensor provided by the present invention;
FIG. 4 is a schematic diagram of a range switching circuit according to the present invention;
FIG. 5 is a schematic diagram illustrating a principle of range refinement in the adaptive range switching temperature sensor provided by the present invention;
FIG. 6 is a schematic flow chart of the detection and control functions implemented by the measurement control circuit in the adaptive range switching temperature sensor provided by the present invention;
FIG. 7 is a schematic diagram of a current generation circuit according to the present invention;
FIG. 8 is a schematic diagram of a modulator circuit according to the present invention;
FIG. 9 is a schematic diagram of a counter circuit according to the present invention;
wherein the reference numerals are:
100: a current generating circuit; 200: a range switching circuit; 300: a modulator circuit;
400: a counter circuit; 500: range control circuit 101: a first operational amplifier;
102: a second operational amplifier; 301: a third operational amplifier; 302: a comparator;
303: a synchronization circuit; 401: a counting module; 402: a timing module;
403: and outputting an indication module.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings, and it is obvious that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The following describes an adaptive span switching temperature sensor provided by an embodiment of the present invention with reference to fig. 1 to 9.
Fig. 1 is a schematic structural diagram of an adaptive span switching temperature sensor provided by the present invention, as shown in fig. 1, including but not limited to: a current generating circuit 100, a range switching circuit 200, a modulator circuit 300, a counter circuit 400, and a range control circuit 500.
The current generation circuit 100 is mainly used for generating a measurement current according to a temperature to be measured; the range switching circuit 200 is mainly used for converting the measurement current according to the bit stream control signal and the range control vector signal to generate a conversion current; the modulator circuit 300 is mainly configured to perform analog-to-digital modulation on the conversion current to generate a bit stream signal; generating a binary signal according to the duty ratio information of the bit stream signal, and outputting a measurement result of the temperature to be measured according to the binary signal; the range control circuit is mainly used for generating the range control vector signal according to the binary signal.
Fig. 2 is a schematic structural view of a temperature sensor in the prior art, and as shown in fig. 2, the temperature sensor in the prior art includes: a current generating circuit, a simple current summing circuit, a sigma-delta modulator circuit, and a counter circuit. The working principle is as follows: the current generated by the current generating circuit is simply summed in a certain proportion and matched with a sigma-delta modulator circuit to form a temperature sensor with a fixed measuring range, and the duty ratio of a generated bit stream signal is in one-to-one correspondence with the temperature. Similar to the temperature sensor shown in fig. 2, all the current temperature sensors adopt a temperature sensing mode with a fixed measuring range, so that different designs are required to be made for different applications, different batches of flow sheets are performed, the manpower resource for design is wasted, and the flow sheet cost is increased.
Fig. 3 is a schematic structural diagram of a temperature sensor with manual range switching provided by the present invention, and as shown in fig. 3, the present invention provides a temperature sensor with manual range switching based on the prior art. The working principle comprises: the measurement current is converted into the temperature measurement range by the range switching circuit 200 in a manner of performing combined operation on the measurement current generated by the temperature generation circuit 100, so that the conversion current corresponding to the temperature measurement range is generated, and the switching of the temperature measurement range is realized by changing the magnitude of the current flowing into the modulator circuit 300.
Alternatively, the modulator circuit 300 employed may be a delta-sigma analog-to-digital conversion circuit (sigma-delta modulation circuit). The sigma-delta modulation circuit reduces the design requirement on an analog circuit by adopting oversampling, noise shaping and digital filtering technologies, and realizes high precision and low power consumption which cannot be achieved by other types of ADCs.
The range switching circuit 100 converts the detected temperature to be measured into a corresponding measurement current through the temperature sensing element.
Alternatively, the measurement current may comprise two types of current signals, such as: one part is a current (called I _ ptat) proportional to the absolute temperature corresponding to the temperature to be measured, and the other part is a current (called I _ be) inversely proportional to the absolute temperature corresponding to the temperature to be measured; or one part of the current is the current proportional to the absolute temperature corresponding to the temperature to be measured, or the current inversely proportional to the absolute temperature corresponding to the temperature to be measured, and the other part of the current is a reference current (such as a constant direct current). That is, in the temperature sensor for manually switching the measuring range, the measuring current generated by the current generating circuit 100 includes two different current signals, but the two current signals carry the temperature information of the temperature to be measured.
Further, an input terminal of the range switching circuit 200 is connected to the current output terminal of the current generating circuit 100, and is used for receiving the measurement current generated by the current generating circuit 100.
Specifically, as shown in fig. 3, the range switching circuit 200, which is preset according to the temperature measurement range, performs a combination operation on the received measurement currents, and then outputs corresponding conversion currents.
Further, the output of the range switching circuit 200 is connected to the input of the modulator circuit 300. The modulator circuit 300 modulates the received converted current (mainly including analog-to-digital conversion) and outputs a bit stream signal containing temperature information of the temperature to be measured.
Wherein a high level duty cycle of the bitstream signal contains the temperature information. For example: the larger the high-level duty ratio acquired in one sampling period is, the higher the corresponding temperature to be measured is.
Further, in order to accurately measure and read the temperature, the adaptive span switching temperature sensor provided by the present invention further includes a counter circuit 400, wherein an input terminal of the counter circuit 400 is connected to an output terminal of the modulator circuit 300, and is configured to quantize the input bitstream signal and output a binary signal containing the temperature information. And finally, converting the binary signal into a corresponding measurement result and outputting the measurement result.
It should be noted that the current generating circuit 100, the modulator circuit 300, and the counter circuit 400 of the present invention may all use conventional circuits in the prior art to perform corresponding functions, and are not described in detail herein.
Compared with the prior art, the self-adaptive range switching temperature sensor provided by the invention is mainly characterized by further comprising a range switching circuit 200, wherein the measuring current output by the current generating circuit 100 can be correspondingly converted according to the bit stream control signal and the range control vector signal and the temperature measuring range, and the switching of the temperature measuring range is realized by changing the magnitude of the current flowing into the modulator circuit.
Wherein the bitstream control signal is determined by the bitstream signal outputted from the modulator circuit 300 in the previous sampling period, so as to determine that the span switching circuit 300 is in the reset state in the current sampling period according to the bitstream signal in the previous sampling period.
For example, at the end of the previous sampling period, the bit stream signal is at a high level, and at this time, the two switches of the element for current conversion corresponding to the bit stream control signal are respectively the switch SW1 being closed and the switch SW2 being open; then switch SW1 is first adjusted to be open and switch SW2 is first adjusted to be closed according to the bitstream control signal during the current sampling period.
The range control vector signal can be input from outside, such as provided by an external signal generator, and the working state of each element in the range switching circuit is changed to realize equal proportion conversion of the measurement current according to different temperature measurement ranges and output corresponding conversion current.
Due to the variable range temperature sensor for manually realizing range switching, the principle of switching to a proper range to realize temperature measurement when the current source is switched in and combined is that the temperature is switched to the proper range according to an actual application scene. Under the condition that the temperature fluctuation range is large or the requirement on temperature measurement precision is high, the whole large range is required to be split by using ranges of several intervals to realize range switching measurement, the configuration setting is required to be manually carried out according to the temperature change of the measured environment, the configuration setting comprises the steps of manually judging whether the currently switched subdivided range is the range which can accurately measure the temperature or not, and the configuration of the range switching circuit is adjusted through the step-by-step judgment, so the measurement time and the complexity are increased.
In view of this, the adaptive range switching temperature sensor provided by the invention is additionally provided with a range control circuit 500 on the basis of the variable range temperature sensor for manually switching the range. The input of the range control circuit 500 is connected to the output of the counter circuit 400 to receive the binary signal generated by the counter circuit 400 and record the N-bit binary number in the preset sampling period.
Further, the range control circuit 500 determines whether the temperature to be measured can be accurately measured in the current range according to the N bit binary number. And if the temperature to be measured cannot be accurately read according to the N-bit binary number, outputting a group of range control vectors to the range switching circuit for controlling the range switching circuit to correspondingly switch the range until the temperature to be measured can be accurately read according to the N-bit binary number.
Further, if the temperature to be measured can be accurately read according to the N bit binary number, the measurement result of the temperature to be measured is directly output according to the binary signal output by the counter circuit 400 without controlling the range switching circuit to perform range switching.
The self-adaptive range switching temperature sensor provided by the invention can realize different range switching by changing current combination operation on a chip on the basis of the traditional temperature sensor, has a large measuring range and high small-range measuring precision, expands the application scene of the temperature sensor with extremely low cost, can meet the requirements of small-range high-precision temperature measurement such as body temperature on the basis of conventional temperature measurement, improves the integration level of a chip and reduces the area of the chip; moreover, the self-adaptive range switching temperature sensor provided by the invention can enable the range of the temperature sensor to have the function of automatic detailed switching by performing detailed splitting on a large temperature measurement range interval and matching with a corresponding modulator circuit and a range control circuit, so that a high-precision range matched with the current measured temperature is automatically searched, and high-precision measurement is realized.
Based on the content of the foregoing embodiment, as an alternative embodiment, in the case that the measurement current includes a first current and a second current different from the first current, the range switching circuit 200 includes: the current mirror circuit comprises a first current mirror group consisting of m parallel current mirrors and a second current mirror group consisting of n parallel current mirrors, wherein each current mirror is connected with a summing node through an independent switch; the first current is connected to the parallel intersection point of the first current mirror group, and the second current is connected to the parallel intersection point of the second current mirror group; the summing node is connected to an input of the modulator circuit.
Fig. 4 is a schematic structural diagram of a range switching circuit provided in the present invention, and as shown in fig. 4, in the adaptive range switching temperature sensor provided in the present invention, a current mirror is mainly used to implement a current conversion function of the range switching circuit 200.
Specifically, the range switching circuit 200 in the adaptive range switching temperature sensor provided by the present invention mainly comprises a series of current mirrors and corresponding pass switches, the current mirrors mirror the current inversely proportional to the absolute temperature and the current directly proportional to the absolute temperature in the current generating circuit 100, and the mirror scale size is calculated according to the required range. Assuming that a current I _ be inversely proportional to the absolute temperature and a current I _ ptat proportional to the absolute temperature are abbreviated, in the span switching circuit 200, the lower half current mirror passes a current that is a multiple of I _ ptat, and the upper half current mirror passes a current that is a multiple of I _ be.
The current mirror, also called as a mirror constant current source, is used for generating a bias current and is used as an active load, and is a standard component commonly existing in an analog integrated circuit.
Specifically, in the adaptive range switching temperature sensor provided by the present invention, m current mirrors are connected in parallel to form a first current mirror group, such as I in fig. 41、I3、I5、I7…In(ii) a At the same time, n current mirrors are connected in parallel to form a second current mirror group, as shown as I in FIG. 42、I4、I6、I8…Im. Each current mirror can be regarded as a current source having a certain proportion (i.e. current transfer ratio) to the input current, and therefore, the current mirrors are referred to as a first current source, a second current source, a third current source, a fourth current source, a fifth current source, a sixth current source, a seventh current source, an eighth current source, … …, an mth current source, and an nth current source, respectively, according to the reference numerals of each current mirror in fig. 4. Where each current source is connected through a switch to a summing node connected to the input of the modulator circuit 300.
Further, the parallel intersection of all current sources in the first current mirror group is connected to a first current (e.g. I _ ptat) in said measurement current, and the parallel intersection of all current sources in the second current mirror group is connected to a first current (e.g. I _ be) in said measurement current. On the basis, all current sources of the first current mirror group are used for charging the summing node according to the input I _ ptat; all current sources of the second current mirror group are used for discharging to the summing node according to the input I _ be.
Finally, the modulator circuit outputs a corresponding bit stream signal to the received measuring current (the measuring current can be determined by the combination operation of the I _ ptat and the I _ be generated by the current generation circuit).
The range switching circuit provided by the invention can realize the conversion of the measuring current, and is mainly represented by the following steps: the on-off of each switch can be controlled according to the bit stream control signal and the range control vector signal to control the on-off between each current source and the summing node, so that the magnitude of the conversion current input to the modulator circuit 300 is controlled, and the range switching is realized.
The self-adaptive range switching temperature sensor provided by the invention utilizes a plurality of current mirrors to form a current mirror group, realizes the adjustment of the input measuring current by controlling whether the current of each current mirror is output to a modulator circuit or not, and provides a method for scientifically and accurately converting the current containing temperature information by changing the input combination of current sources according to a range control vector signal, and the self-adaptive range switching temperature sensor has strong controllability, is simple to operate, and expands the application scene of the temperature sensor with extremely low cost.
Based on the content of the foregoing embodiment, as an optional embodiment, the first current mirror group at least includes a first current mirror with a mirror ratio size of 1, the second current mirror group at least includes a second current mirror with a mirror ratio size of 1, and switches corresponding to the first current mirror and the second current mirror are normally closed; the first current mirror group at least further comprises a third current mirror with a mirror ratio size of 1, the second current mirror group at least further comprises a fourth current mirror with a mirror ratio size of 1, and the bit stream control signal is used for controlling switches corresponding to the third current mirror and the fourth current mirror; the measuring range control vector signal is used for controlling switches corresponding to other current mirrors except the first current mirror, the second current mirror, the third current mirror and the fourth current mirror.
Based on the content of the foregoing embodiments, as an alternative embodiment, the first current mirror I with the mirror scale size of 1 may be selected1A second current mirror I2A third current mirror I3And a fourth current mirror I4Wherein the first current mirror I1And a second current mirror I3Is identical to the second current mirror I2And a fourth current mirror I4The current direction of (2) is opposite.
Wherein, the first current mirror I1A second current mirror I2The corresponding switch is in a normally-closed state, and the third current mirror I3The fourth current mirror I4The corresponding switch states are opposite, i.e. in the fourth current mirror I4When the corresponding switch is closed, the third current mirror I3The corresponding switch is disconnected; at the fourth current mirror I4When the corresponding switch is turned off, the third current mirror I3The corresponding switch is closed.
Specifically, switches corresponding to the third current mirror and the fourth current mirror are controlled by two opposite signals, and the signal is the output Bit _ Stream of the sigma-delta modulator circuit; the switches corresponding to the first current mirror and the second current mirror are in a normally-off state in the invention. The switches corresponding to the first current mirror and the second current mirror to the switches corresponding to the mth current mirror and the nth current mirror are controlled by a control vector, the control vector is a range switching control signal, and after the switches corresponding to the fifth current mirror and the sixth current mirror to the switches corresponding to the mth current mirror and the nth current mirror are controlled to be closed according to vector combination, the fifth current mirror and the sixth current mirror to the mth current mirror and the nth current mirror are connected to a current summation node, so that the number of the third current mirror and the fourth current mirror can be equivalently changed, the current combination operation formula is equivalently changed, and the switching of the range is realized. The range control vector of this embodiment controls the switch corresponding to the fifth current mirror to the switches corresponding to the mth current mirror and the nth current mirror, thereby realizing different range controls.
In the case where I _ ptat is all charged to the summing node and I _ be is all discharged to the summing node, the calculation formula of the duty ratio of the bit stream signal is:
Figure BDA0002894632440000141
wherein k is1Is the sum of the mirror scale dimensions, k, of all the current mirrors charging the summing node2Is the sum of the mirror scale sizes of all the current mirrors discharging to the summing node.
Therefore, the self-adaptive range switching temperature sensor provided by the invention is realized by the first current mirror I1A second current mirror I2A third current mirror I3And a fourth current mirror I4The corresponding switch is arranged as above, so that the reference duty ratio can be obtained, and the calibration operation of the whole self-adaptive range switching temperature sensor can be realized according to the reference duty ratio at the later stage.
Fig. 5 is a schematic diagram illustrating a range refining principle in the adaptive range switching temperature sensor provided by the present invention, and as shown in fig. 5, a waveform in a left side diagram is a wide-range temperature duty ratio corresponding curve (a horizontal axis represents temperature, and a vertical axis represents duty ratio), and when a temperature range of-40 to 125 ℃ corresponds to a duty ratio change of 10% to 90%, a duty ratio change of 1% corresponds to a temperature change of about 2 ℃. The waveform in the right graph is a temperature duty ratio corresponding curve after the range is thinned, the whole wide range is divided into about 5 thinned sub-ranges, each sub-range can quantize the temperature in the range by using 10% -90% duty ratio, and therefore, the accuracy of the wide range is improved by about 5 times compared with that of the wide range shown in the graph. The adaptive range switching temperature sensor provided by the embodiment of the invention can automatically generate a range control vector signal based on the binary signal output by the counter circuit 400 through the range control circuit 500 so as to carry out combined control on the switches of all the current mirrors and realize automatic detailed switching of the range.
Optionally, during the range subdivision, an overlap of a preset proportion (e.g. 10%) may be set between every two adjacent sub-ranges, so as to avoid an increase in sampling error of a subsequent circuit at a low duty ratio.
Further, in order to realize automatic range setting, in the adaptive range switching temperature sensor provided by the present invention, the range control circuit 500 at least includes a range control scheme storage module to store a plurality of range control schemes in advance; each range control scheme is a scheme for controlling the switching state of each current mirror according to different ranges; and each range control scheme corresponds to different range control gears in sequence based on the temperature measurement sequence corresponding to the range of each range control scheme.
As shown in fig. 5, a control scheme for dividing the wide-range into 5 sub-ranges can be pre-calculated, and it is assumed that, in combination with fig. 4, the original wide-range switches correspond to the states of switch SW1 closed, SW2 closed, SW3 open, SW4 closed, and all other switches SW5-SWn are open. When the wide range is divided into sub-ranges corresponding to the curve C, the corresponding switch states are as follows: switch SW1 is closed, SW2 is closed, SW3 is open, SW4 is closed, SW5 and SW6 are closed, and all other switches SW7-SWn are open. When the wide range is divided into sub-ranges corresponding to the curve E, the corresponding switch states are as follows: switch SW1 is closed, SW2 is closed, SW3 is open, SW4 is closed, SW5-SW8 are closed, all other switches SW9-SWn are open. When the wide range is divided into sub-ranges corresponding to the curve G, the corresponding switch states are: switch SW1 is closed, SW2 is closed, SW3 is open, SW4 is closed, SW5-SW10 are closed, all other switches SW11-SWn are open. When the wide range is divided into sub-ranges corresponding to the curve J, the corresponding switch states are: switch SW1 is closed, SW2 is closed, SW3 is open, SW4 is closed, SW5-SW12 are closed, all other switches SW13-SWn are open. When the wide range is divided into sub-ranges corresponding to the curve L, the corresponding switch states are as follows: switch SW1 is closed, SW2 is closed, SW3 is open, SW4 is closed, SW5-SW14 are closed, all other switches SW15-SWn are open. When the wide range is divided into sub-ranges corresponding to the curve B, the corresponding switch states are as follows: switch SW1 is closed, SW2 is closed, SW3 is open, SW4 is closed, SW5-SW16 are closed, all other switches SW17-SWn are open. When the wide range is divided into sub-ranges corresponding to the curve N, the corresponding switch states are as follows: switch SW1 is closed, SW2 is closed, SW3 is open, SW4 is closed, SW5-SW18 are closed, all other switches SW19-SWn are open.
Then the scheme of controlling the switching state of each of the current mirrors according to each of the different measurement ranges (each sub-range corresponding to curve E-curve N) is used as a measurement range control scheme. Optionally, the numbers may be numbered according to a temperature measurement sequence corresponding to the measurement range, such as: the range control schemes corresponding to the curves E-N are numbered as control schemes 1-6 in sequence, and each sub-range is used as a range control gear according to the numbering sequence, so that the corresponding range control gear can be selected according to different range control vector signals.
The self-adaptive range switching temperature sensor provided by the invention has the advantages that a plurality of different range control gears are preset, the range control scheme corresponding to each range control gear is stored in the range control circuit, after the range control circuit acquires the binary signal of the counter circuit, whether the temperature to be measured can be accurately read in the current range can be judged according to the analysis result of the binary signal, the corresponding range control vector signal can be automatically generated under the condition of large reading error judgment, the corresponding range control scheme is called through the range control vector signal, the range switching circuit is controlled to realize range switching, the range switching can be effectively and autonomously realized, and the measurement precision is improved.
Fig. 6 is a schematic flow chart of a process control circuit for implementing detection and control functions in the adaptive range switching temperature sensor provided in the present invention, and as shown in fig. 6, the process control circuit generates the range control vector signal according to the binary signal, and specifically includes:
the measuring range control circuit acquires binary data in the binary signal; under the condition that all binary data are determined to be 0, generating a range downshift control vector signal; under the condition that all binary data are determined to be 1, generating a range upshift control vector signal; the range downshift control vector signal is a signal related to a range control scheme corresponding to the next range control gear, which is called from the range control scheme storage module; the range upshift control vector signal is a signal related to the range control scheme corresponding to the previous range control gear, which is called from the range control scheme storage module.
Specifically, the range control circuit 500 provided by the present invention collects and analyzes the N-bit binary number output by the counter circuit 400 to realize the range switching through the range switching circuit 200. Taking the wide-range subdivision diagram shown in fig. 5 as an example, the following description is made:
assuming that the current range is the sub-range corresponding to the curve G, under the condition that the obtained N bit binary numbers are all 0, it indicates that the current range is higher, and the actual temperature value is lower than the current range, the control range is changed to a lower level and then measured again, and then a downshift control vector signal is generated and sent to the range switching circuit 200. The range switching circuit 200 turns off the switch SW9 and the switch SW10 according to the downshift control vector signal to switch the range to the sub-range corresponding to the curve E and continue normal temperature measurement.
Further, if the N bit binary number obtained after the switching is still 0, the current measurement range is continuously switched from the sub-measurement range corresponding to the curve E to the sub-measurement range corresponding to the curve C until the obtained N bit binary numbers are not all 0, which proves that the measurement range switching is completed, and normal temperature measurement is started.
Assuming that the current measurement range is the sub-measurement range corresponding to the curve G, if the acquired N bit binary numbers are not all 0, it is determined whether all 1 are available. If the number of the binary numbers of the acquired N bits is not all 0, the switching of the measuring range is proved to be finished, and normal temperature measurement is started.
Further, the range control circuit generates the range control vector signal according to the binary signal, and further includes:
the range control circuit judges whether the temperature corresponding to the binary signal is within a preset range of the current range under the condition that the binary data are not all 0 and not all 1; and if the current range is not within the preset range, generating a range downshift control vector signal.
For example, assuming that the current range is a sub-range corresponding to the curve G, and when the obtained N bit binary numbers are not all 1 (nor all 0), it is determined whether the temperature duty ratio corresponding to the binary number value is within the preset interval of the current range.
The preset interval is a duty cycle interval (generally set to be 20% -90%) capable of accurately measuring temperature; correspondingly, the duty cycle interval of 10% -20% is the interval with the risk of increasing the sampling error.
If not, that is, if the value is in the interval with the risk of increasing the sampling error, there is a risk of increasing the sampling error, and the first-gear range needs to be reduced. According to the invention, by arranging the overlapping region (about 10%) between different ranges, after the ranges are reduced, the actual temperature is in the large duty ratio region of the low range, which is beneficial to improving the sampling precision. If the numerical value is in the preset interval, the interval at the moment is the proper range interval, the temperature sensor normally measures and normally outputs data.
It should be noted that the control flow given here is a priority control flow, and other control flows of the same algorithm may also be sampled in practice, for example, whether N-bit binary data is all 1 is determined first, and then whether N-bit binary data is all 0 is determined.
The invention provides a self-adaptive range switching temperature sensor, which correspondingly generates a corresponding range control vector signal according to binary data output by a counter circuit, so as to automatically realize range matching according to the current temperature measurement requirement, refine and split a large temperature measurement range interval, and match a corresponding sigma-delta modulator circuit and a range detection and automatic switching circuit designed by the invention, so that the range of the temperature sensor has the function of automatic refined switching, and a high-precision range matched with the currently measured temperature is automatically searched, thereby realizing high-precision measurement.
Meanwhile, the adaptive range switching temperature sensor provided by the invention has the advantages that the increase of the chip area is very small by arranging the range switching circuit and the range control circuit, the application scene of the temperature sensor chip is expanded at very low cost, the automation and the adaptive degree of the temperature measurement chip are improved, and the time cost during temperature measurement is also saved.
Based on the content of the foregoing embodiment, as an optional embodiment, all of the m parallel current mirrors forming the first current mirror group are PMOS transistors; the n parallel current mirrors forming the second current mirror group are all NMOS transistors;
the grid electrode of each PMOS transistor is connected in parallel and is connected with the mirror voltage of the ground current mirror corresponding to the first current; the source stage of each PMOS transistor is connected in parallel and grounded; the drain of each PMOS transistor is respectively connected with one end of a switch, and the other end of each switch is connected in parallel and is connected into the summing node;
correspondingly, the grid electrode of each NMOS transistor is connected in parallel and is connected with the mirror image voltage of the ground current mirror corresponding to the second current; the source stage of each NMOS transistor is connected in parallel and grounded; and the drain of each NMOS transistor is respectively connected with one end of a switch, and the other end of each switch is connected in parallel and is connected into the summing node.
In the adaptive range switching temperature sensor provided by the invention, the range switching circuit 200 mainly comprises a series of PMOS and NMOS transistors and corresponding switches, the transistors are current mirrors, the current I _ ptat inversely proportional to absolute temperature and the current I _ be directly proportional to absolute temperature in the mirror current generation circuit 100 are mirrored, and the mirror scale size is calculated according to the required range. In the scale switching circuit 200, the NMOS transistor flows a current that is a multiple of I _ ptat, and the PMOS transistor flows a current that is a multiple of I _ be.
Based on the above circuit, the first switch SW1 and the second switch SW2 are controlled by two signals opposite to each other, which are the output bitstream signal Bit _ Stream of the sigma-delta modulator circuit 200. The third switch SW3 and the fourth switch SW4 are normally on states in the present invention; the fifth switch SW5, the sixth switch SW6, the mth switch SWm and the nth switch SWn are controlled by a range control vector signal, the range control vector signal is a range switching control signal, after the fifth switch, the sixth switch, the mth switch and the nth switch are controlled and closed according to vector combination, the fifth current mirror PMOS3, the sixth current mirror NMOS3, the mth current mirror and the nth current mirror are connected to a current summing node, the number of the third current mirror PMOS2 and the number of the fourth current mirror NMOS2 can be equivalently changed, equivalent is a current combination operation formula change, and therefore range switching is achieved.
As a specific embodiment, in the range switching circuit, a mirror ratio size of the first PMOS transistor is 1, a mirror ratio size of the second PMOS transistor is 1, a mirror ratio size of the third PMOS transistor is 5, a mirror ratio size of the first NMOS transistor is 1, a mirror ratio size of the second NMOS transistor is 1, a mirror ratio size of the third NMOS transistor is 6, the mirror ratio sizes are calculated according to a range of-40 to 125 ℃ and a range of 20 to 50 ℃, and a duty ratio formula corresponding to the two temperature measurement ranges is as follows:
Figure BDA0002894632440000201
Figure BDA0002894632440000202
it can be seen that the denominator I _ ptat + I _ be is a temperature-independent current, the numerator combination is a temperature-dependent value, and the duty ratios obtained by different combination operations are different, thereby realizing different application ranges.
Based on the above principle analysis, those skilled in the art should understand that different design ranges may correspond to different combination operation forms, and in the embodiment, only the switching of two specific ranges is illustrated, and in practical application, many different range switching may be designed according to the situation.
It should be noted that, in the specific application of the present invention, the mirror scale sizes of the m + n current mirrors are respectively fixed, but in other range applications, different current mirror scales may be adopted to implement different combination operations according to actual calculation requirements, and various current mirror scales are included in the protection scope of the present invention, that is, the present invention does not specifically limit the mirror scale size of each current mirror.
Fig. 7 is a schematic structural diagram of a current generating circuit according to the present invention, and as shown in fig. 7, the current generating circuit 100 mainly includes: the first PNP triode PNP1, the second PNP transistor PNP2, the first resistor R1, the second resistor R2, the third resistor R3, the fourth resistor R4, the first operational amplifier 101, the second operational amplifier 102, the second capacitor C2, the fourth PMOS transistor PMOS4, the fifth PMOS transistor PMOS5, the sixth PMOS transistor PMOS6, the fourth NMOS transistor NMOS4, the fifth NMOS transistor NMOS5, and the sixth NMOS transistor NMOS 6.
Wherein the base of the first PNP transistor PNP1 is connected to the collector of the first PNP transistor PNP1, the base of the second PNP transistor PNP2, the collector of the second PNP transistor PNP2, one end of the second capacitor C2, the source of the fifth NMOS transistor NMOS5, and one end of the fourth resistor R4, and is connected to ground;
an emitter of the first PNP transistor PNP1 is connected to one end of the first resistor R1 and the positive input end of the first operational amplifier 101;
the negative input end of the first operational amplifier 101 is connected with one end of the second resistor R2 and one end of the third resistor R3;
the output end of the first operational amplifier 101 is connected with the gate NMOS4 of the fourth NMOS transistor;
the source of the fourth NMOS transistor NMOS4 is connected with the other end of the first resistor R1, the other end of the second resistor R2 and the other end of the second capacitor C2;
a drain of the fourth NMOS transistor NMOS4 is connected to a drain of the fourth PMOS transistor PMOS4, a gate of the fourth PMOS transistor PMOS4, and a gate of the fifth PMOS transistor PMOS 5;
the source of the fourth NMOS transistor NMOS4 is connected with the source of the fifth PMOS transistor PMOS5, the source of the sixth PMOS transistor PMOS6 and is connected with a power supply;
the drain of the fifth PMOS transistor PMOS5 is connected to the drain of the fifth NMOS transistor NMOS5 and the gate of the fifth NMOS transistor NMOS5, and outputs the first current I _ ptat;
the gate of the sixth PMOS transistor PMOS6 is connected to the drain of the sixth PMOS transistor PMOS6 and the drain of the sixth NMOS transistor NMOS6, and outputs the second current I _ be;
the gate of the sixth PMOS transistor PMOS6 is connected to the output terminal of the second operational amplifier 102;
the source of the sixth PMOS transistor PMOS6 is connected to the other end of the fourth resistor R4 and the negative input end of the second operational amplifier 102;
the positive input terminal of the second operational amplifier 102 is connected to the emitter of the second PNP transistor PNP2 and the other terminal of the third resistor R3.
It should be noted that the current generating circuit 100 provided in the present invention is a specific embodiment, and other current generating circuits may be adopted, which essentially need to generate a current proportional to absolute temperature and a current inversely proportional to absolute temperature, or a current combining the two currents for the subsequent range switching circuit to perform the combination operation.
Fig. 8 is a schematic structural diagram of a modulator circuit provided in the present invention, and as shown in fig. 8, the modulator circuit 300 mainly includes: a first capacitor C1, a third operational amplifier 301, a comparator 302 and a synchronization circuit 303.
The third operational amplifier 301 and the first capacitor C1 form an integrated circuit, one end of the first capacitor C1 is connected to the negative input terminal of the third operational amplifier 301, the other end of the first capacitor C1 is connected to the output terminal of the third operational amplifier 301 and the negative input terminal of the comparator 302, and the positive input terminal of the third operational amplifier 301 is connected to an integrated reference voltage REF corresponding to the measurement current;
the positive input end of the comparator 302 is connected to a comparator threshold voltage VTH;
the output terminal of the comparator 302 is connected to the synchronization circuit 303, and the synchronization circuit 303 is configured to generate the bitstream signal Bit _ Stream according to the comparison result output by the comparator 302 in a system clock cycle.
It should be noted that, the present invention provides a sigma-delta modulator circuit, and optionally, other modulator circuits may also be used, and the other modulator circuits may make appropriate changes in structure according to actual use situations, and essentially need to integrate the currents after the combined operation by an integrator, and then compare the integrated currents by a comparator, and output a bitstream signal Bit _ Stream whose duty cycle includes temperature information, and the synchronization circuit 303 is configured to synchronously generate the bitstream signal Bit _ Stream by using a system clock, so as to facilitate the subsequent quantization by using the counter circuit 400, so as to reduce the sampling error.
Fig. 9 is a schematic structural diagram of a counter circuit provided in the present invention, and as shown in fig. 9, the counter circuit 400 mainly includes: a counting module 401, a timing module 402 and an output indication module 403;
the counting module 401 is mainly configured to receive the bitstream signal and quantize the duty ratio information in the bitstream signal to output binary data corresponding to the measurement result of the temperature to be measured; the timing module 402 is mainly used for controlling a time period for converting the measurement current and controlling a counting duration of the counting module; the output indication module 403 is mainly configured to reset the counting module 401 and the timing module 402 after outputting the measurement result.
Specifically, the counting module 401 is configured to quantize bitstream information output by the pre-stage sigma-delta modulator circuit 300, and extract temperature information.
The timing module 402 is used to control the setup time of the sigma-delta modulator circuit 300 and the counting duration of the counting module 401.
The output indication module 403 is used to inform the next stage that the output is ready after the counting is completed, and reset the timing module 402 and the counting module 401 after a certain period of time, so as to start a new round of detection.
It should be noted that the counter circuit 400 provided by the present invention is the most specific embodiment, and other counter circuits may also be adopted, and the structures of the other counter circuits may be changed according to the actual use situation, for example, on the basis of the circuit structure shown in fig. 9, if the output bit number needs to be changed, the timing duration may be changed accordingly, and the like.
Based on the content of the foregoing embodiment, as an optional embodiment, the first current is proportional to an absolute temperature corresponding to the temperature to be measured; the second current is inversely proportional to the absolute temperature corresponding to the temperature to be measured.
The self-adaptive range switching temperature sensor provided by the invention directly generates I _ ptat which is in direct proportion to the absolute temperature corresponding to the temperature to be measured and I _ be which is in inverse proportion to the absolute temperature corresponding to the temperature to be measured by using the current generating circuit 100, so that a range control vector signal can be reasonably configured by using the range switching circuit 200 according to the temperature measuring range at a later stage, the input current is modulated to generate the measuring current, and the accuracy of range switching is effectively improved.
Based on the content of the foregoing embodiment, as an alternative embodiment, the bitstream control signal is determined according to the high-low state of the bitstream signal; the bit stream control signal is used for controlling switches corresponding to the third current mirror and the fourth current mirror, and specifically includes: under the condition that the bit stream signal acquired at the end of the last sampling period is at a high level, the corresponding bit stream control signal controls the switch corresponding to the third current mirror to be switched off and controls the switch corresponding to the fourth current mirror to be switched on; correspondingly, when the bit stream signal obtained at the end of the last sampling period is at a low level, the corresponding bit stream control signal controls the switch corresponding to the third current mirror to be closed, and controls the switch corresponding to the fourth current mirror to be opened.
According to the self-adaptive range switching temperature sensor, on the basis of realizing the configuration of the range switching circuit by using the quantity control vector signal, the bit stream control signal is generated according to the high and low level states of the bit stream signal, so that the generated test quantity current is rectangular wave current, a foundation is provided for quantifying the duty ratio of the bit stream signal by a later counter circuit, and the measurement precision is effectively improved.
In summary, the adaptive range switching temperature sensor provided by the invention creatively provides a range switching circuit to match with a corresponding sigma-delta modulator circuit, so that the range of the temperature sensor has a hot switching function, and can be freely switched in one or more temperature measurement ranges under the condition of no power failure. The design mode has the advantages that the increase of the area of the chip is very small, the application scene of the temperature sensor chip is expanded at very low cost, the integration level of the chip is improved, and the cost increased by multi-version differentiation is saved.
The above-described embodiments of the apparatus are merely illustrative, and the units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of the present embodiment. One of ordinary skill in the art can understand and implement it without inventive effort.
Through the above description of the embodiments, those skilled in the art will clearly understand that each embodiment can be implemented by software plus a necessary general hardware platform, and certainly can also be implemented by hardware. With this understanding in mind, the above-described technical solutions may be embodied in the form of a software product, which can be stored in a computer-readable storage medium such as ROM/RAM, magnetic disk, optical disk, etc., and includes instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute various embodiments or some portions of embodiments described above.
Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.

Claims (10)

1. An adaptive range switching temperature sensor, comprising at least:
the device comprises a current generating circuit, a range switching circuit, a modulator circuit, a counter circuit and a range control circuit;
the current generating circuit is used for generating a measuring current according to the temperature to be measured;
the range switching circuit is used for converting the measuring current according to a bit stream control signal and a range control vector signal to generate a conversion current;
the modulator circuit is used for carrying out analog-to-digital modulation on the conversion current to generate a bit stream signal;
the counter circuit is used for receiving the bit stream signal, generating a binary signal according to the duty ratio information of the bit stream signal, and outputting the measurement result of the temperature to be measured according to the binary signal;
the range control circuit is used for generating the range control vector signal according to the binary signal.
2. The adaptive range switching temperature sensor of claim 1 wherein, where the measurement current comprises a second current distinct from the first current and from the first current, the range switching circuit comprises:
the current mirror circuit comprises a first current mirror group consisting of m parallel current mirrors and a second current mirror group consisting of n parallel current mirrors, wherein each current mirror is connected with a summing node through an independent switch;
the first current is connected to the parallel intersection point of the first current mirror group, and the second current is connected to the parallel intersection point of the second current mirror group;
the summing node is connected to an input of the modulator circuit.
3. The adaptive span switching temperature sensor of claim 2 wherein the span control circuit includes at least a span control scheme storage module to pre-store a plurality of span control schemes;
each measuring range control scheme is a scheme for controlling the switching state of each current mirror according to different measuring ranges;
and on the basis of the temperature measurement sequence corresponding to the range of each range control scheme, each range control scheme corresponds to different range control gears in sequence.
4. The adaptive span switching temperature sensor of claim 3 wherein the span control circuit generates the span control vector signal based on the binary signal, including:
the measuring range control circuit acquires binary data in the binary signal;
under the condition that all the binary data are determined to be 0, generating a range downshift control vector signal;
under the condition that all the binary data are determined to be 1, generating a range upshift control vector signal;
the range downshift control vector signal is a signal related to a range control scheme corresponding to the next range control gear, which is called from the range control scheme storage module;
the range upshift control vector signal is a signal related to the range control scheme corresponding to the previous range control gear, which is called from the range control scheme storage module.
5. The adaptive range switching temperature sensor of claim 4 wherein the range control circuit generates the range control vector signal based on the binary signal, further comprising:
the range control circuit judges whether the temperature corresponding to the binary signal is within a preset range of the current range under the condition that the binary data are not all 0 and not all 1;
and if the current range is not within the preset range, generating a range downshift control vector signal.
6. The adaptive range-switching temperature sensor of claim 2,
the first current mirror group at least comprises a first current mirror with a mirror ratio size of 1, the second current mirror group at least comprises a second current mirror with a mirror ratio size of 1, and switches corresponding to the first current mirror and the second current mirror are normally closed;
the first current mirror group at least comprises a third current mirror with the mirror image proportion size of 1, and the second current mirror group at least comprises a fourth current mirror with the mirror image proportion size of 1;
the bit stream control signal is used for controlling switches corresponding to the third current mirror and the fourth current mirror;
the measuring range control vector signal is used for controlling switches corresponding to other current mirrors except the first current mirror, the second current mirror, the third current mirror and the fourth current mirror.
7. The adaptive range switching temperature sensor of claim 2, wherein the m parallel current mirrors forming the first current mirror group are all PMOS transistors; the n parallel current mirrors forming the second current mirror group are all NMOS transistors;
the grid electrode of each PMOS transistor is connected in parallel and is connected with the mirror voltage of the ground current mirror corresponding to the first current; the source stage of each PMOS transistor is connected in parallel and grounded; the drain of each PMOS transistor is respectively connected with one end of a switch, and the other end of each switch is connected in parallel and is connected into the summing node;
correspondingly, the grid electrode of each NMOS transistor is connected in parallel and is connected with the mirror image voltage of the ground current mirror corresponding to the second current; the source stage of each NMOS transistor is connected in parallel and grounded; and the drain of each NMOS transistor is respectively connected with one end of a switch, and the other end of each switch is connected in parallel and is connected into the summing node.
8. The adaptive range switching temperature sensor of claim 2, wherein the current generating circuit comprises: first PNP triode, second PNP transistor, first resistance, second resistance, third resistance, fourth resistance, first fortune is put, second electric capacity, fourth PMOS transistor, fifth PMOS transistor, sixth PMOS transistor, fourth NMOS transistor, fifth NMOS transistor, sixth NMOS transistor, wherein:
the base stage of the first PNP triode is connected with the collector electrode of the first PNP triode, the base stage of the second PNP triode, the collector electrode of the second PNP triode, one end of the second capacitor, the source electrode of the fifth NMOS transistor and one end of the fourth resistor, and is connected with the ground;
an emitter of the first PNP triode is connected to one end of the first resistor and the positive input end of the first operational amplifier;
the negative input end of the first operational amplifier is connected with one end of the second resistor and one end of the third resistor;
the output end of the first operational amplifier is connected with the grid electrode of the fourth NMOS transistor;
the source of the fourth NMOS transistor is connected with the other end of the first resistor, the other end of the second resistor and the other end of the second capacitor;
the drain of the fourth NMOS transistor is connected with the drain of the fourth PMOS transistor, the grid of the fourth PMOS transistor and the grid of the fifth PMOS transistor;
the source electrode of the fourth NMOS transistor is connected with the source electrode of the fifth PMOS transistor, the source electrode of the sixth PMOS transistor and a power supply;
the drain of the fifth PMOS transistor is connected with the drain of the fifth NMOS transistor and the grid of the fifth NMOS transistor and outputs the first current;
the grid electrode of the sixth PMOS transistor is connected with the drain electrode of the sixth PMOS transistor and the drain electrode of the sixth NMOS transistor and outputs the second current;
the grid electrode of the sixth PMOS transistor is connected with the output end of the second operational amplifier;
the source of the sixth PMOS transistor is connected with the other end of the fourth resistor and the negative input end of the second operational amplifier;
and the positive input end of the second operational amplifier is connected with the emitter of the second PNP triode and the other end of the third resistor.
9. The adaptive range switching temperature sensor of claim 1, wherein the modulator circuit comprises: the first capacitor, the third operational amplifier, the comparator and the synchronous circuit;
the third operational amplifier and the first capacitor form an integrating circuit, one end of the first capacitor is connected with the negative input end of the third operational amplifier, the other end of the first capacitor is connected with the output end of the third operational amplifier and the negative input end of the comparator, and the positive input end of the third operational amplifier is connected with an integrating reference voltage corresponding to the measuring current;
the positive input end of the comparator is connected with the threshold voltage of the comparator;
the output end of the comparator is connected with the synchronous circuit, and the synchronous circuit is used for generating the bit stream signal according to the comparison result output by the comparator in the system clock period.
10. The adaptive range switching temperature sensor of claim 1, wherein the counter circuit comprises: the device comprises a counting module, a timing module and an output indicating module;
the counting module is used for receiving the bit stream signal and quantizing the duty ratio information in the bit stream signal so as to output binary data corresponding to the measurement result of the temperature to be measured;
the timing module is used for controlling the time period for converting the measuring current and controlling the counting duration of the counting module;
the output indication module is used for resetting the counting module and the timing module after the measuring result is output.
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Publication number Priority date Publication date Assignee Title
CN114879808A (en) * 2022-04-08 2022-08-09 北京智芯微电子科技有限公司 Temperature detection chip, PTAT circuit thereof and temperature sensor
CN115060962A (en) * 2022-08-16 2022-09-16 苏州联讯仪器有限公司 Source meter capable of rapidly switching measuring range and temperature compensation method thereof
CN117589704A (en) * 2024-01-18 2024-02-23 上海科泽智慧环境科技有限公司 Range self-switching control method and system for water quality on-line monitoring

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CN114879808A (en) * 2022-04-08 2022-08-09 北京智芯微电子科技有限公司 Temperature detection chip, PTAT circuit thereof and temperature sensor
CN114879808B (en) * 2022-04-08 2024-01-23 北京智芯微电子科技有限公司 Temperature detection chip, PTAT circuit thereof and temperature sensor
CN115060962A (en) * 2022-08-16 2022-09-16 苏州联讯仪器有限公司 Source meter capable of rapidly switching measuring range and temperature compensation method thereof
CN115060962B (en) * 2022-08-16 2022-12-09 苏州联讯仪器有限公司 Source meter capable of rapidly switching measuring range and temperature compensation method thereof
CN117589704A (en) * 2024-01-18 2024-02-23 上海科泽智慧环境科技有限公司 Range self-switching control method and system for water quality on-line monitoring
CN117589704B (en) * 2024-01-18 2024-03-29 上海科泽智慧环境科技有限公司 Range self-switching control method and system for water quality on-line monitoring

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