CN112816088B

CN112816088B - Self-adaptive range switching temperature sensor

Info

Publication number: CN112816088B
Application number: CN202110036726.0A
Authority: CN
Inventors: 毕见鹏
Original assignee: Beijing Microchip Blockchain And Edge Computing Research Institute
Current assignee: Beijing Microchip Blockchain And Edge Computing Research Institute
Priority date: 2021-01-12
Filing date: 2021-01-12
Publication date: 2023-06-06
Anticipated expiration: 2041-01-12
Also published as: CN112816088A

Abstract

The invention provides a self-adaptive range switching temperature sensor, which comprises: the current generation circuit is used for generating a measurement current according to the temperature to be measured; the range switching circuit is used for converting the measured current according to the bit stream control signal and the range control vector signal to generate a converted current; the modulator circuit is used for carrying out analog-digital modulation on the converted 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, the large temperature measurement range is subjected to refinement and split, and the corresponding modulator circuit and range control circuit are matched, so that the range of the temperature sensor has the function of automatic refinement and switching, and a high-precision range matched with the current measured temperature is automatically searched, thereby realizing high-precision measurement.

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

Temperature sensors, especially on-chip temperature sensors, are widely used in various chip internal designs due to their high integration, and their basic working principle is: the method comprises the steps of generating a current sum which is inversely proportional to absolute temperature and a current which is directly proportional to absolute temperature through a triode and an operational amplifier, carrying out combined operation on the two currents, then realizing charge and discharge of a capacitor through an integrator, generating a bit stream signal containing temperature information through a comparator by charge and discharge voltage, wherein the duty ratio of the bit stream signal is directly proportional to the temperature, and outputting a bit stream signal which can be sampled and quantized by a digital signal after digital domain clock synchronization.

The principle of the conventional temperature sensor when combining the proportional current and the inverse current is that: the temperature change range (temperature measurement range) is corresponding to the whole duty ratio range as much as possible, if the corresponding is not full, the duty ratio range is smaller in utilization ratio, and the quantization bit number is fixed, so that the precision required by unit stepping is high, and the design requirement of minimum precision cannot be finally realized due to mismatch reasons. In addition, in the actual design, in order to avoid process deviation and sampling error, certain margin is reserved at the position with the maximum duty ratio and the minimum duty ratio, and only the middle 80% -90% duty ratio range is used, so that the precision requirement is higher and the implementation is more difficult.

Case 1: in a conventional fixed-range temperature sensor, for example, the range is-40-125 ℃, the temperature range is mapped to the whole duty ratio range in actual design, and a temperature precision (called precision 1) is correspondingly obtained, if the fixed-range temperature sensor is applied to a scene with a small temperature range, for example, 20-50 ℃, the actual duty ratio change range occupies only about one fifth of the designed range, so that the range of about four fifths of the range is wasted, and only the measurement precision of precision 1 can be realized, so that the measurement precision often cannot meet the actual requirement.

Case 2: if the same voltage and number of temperature sensors are designed with a range of 20-50 degrees celsius, the design will map this relatively small temperature range to the entire duty cycle range, since the duty cycle range is fixed, while a relatively higher and more easily achievable measurement accuracy (referred to as accuracy 2) is obtained in the small temperature range, this temperature sensor is also limited to measuring a larger temperature range.

The two conditions need to be designed differently according to different measuring objects and different applications, and flow sheets of different batches are carried out, so that the manpower resources of the design are wasted, and the flow sheet cost is increased.

Disclosure of Invention

Aiming at the problems existing in the prior art, the embodiment of the invention provides the self-adaptive range switching temperature sensor, which improves the automation and self-adaptive degree of temperature measurement of the temperature sensor, reduces the operation complexity and can effectively improve the measurement accuracy.

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 generation circuit is used for generating a measuring current according to the temperature to be measured; the measuring range switching circuit is used for converting the measured current according to the bit stream control signal and the measuring range control vector signal to generate a converted current; a modulator circuit for performing analog-to-digital modulation on the converted 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 range switching temperature sensor provided by the invention, in the case that the measured current includes a first current and a second current different from the first current, the range switching circuit includes:

A first current mirror group formed by m parallel current mirrors and a second current mirror group formed by n parallel current mirrors, wherein each current mirror is connected with a summation 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 for storing 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; based on the temperature measuring sequence corresponding to the measuring range of each measuring range control scheme, each measuring range control scheme sequentially corresponds to different measuring range control gears.

The self-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 specifically comprises the following steps: the range control circuit acquires binary data in the binary signal; generating a range down shift control vector signal if it is determined that all of the binary data are 0; generating a span upshift control vector signal in the event that it is determined that all of the binary data are 1; the range down shift 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 a range control scheme corresponding to a last 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 measuring range control circuit judges whether the temperature corresponding to the binary signal is in a preset range of the current measuring range or not under the condition that the binary data are not all 0 and not all 1; and if the range is not within the preset range, generating a range down shift 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 the mirror image proportion size of 1, the second current mirror group at least comprises a second current mirror with the mirror image proportion size of 1, and the 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 proportion size of 1, and the second current mirror group at least comprises a fourth current mirror with the mirror proportion size of 1; the bit flow control signal is used for controlling the switches corresponding to the third current mirror and the fourth current mirror; the range control vector signal is used for controlling the switches corresponding to the 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 PMOS transistors; n parallel current mirrors forming the second current mirror group are NMOS transistors; the grid electrode of each PMOS transistor is connected in parallel, and the mirror voltage of the current mirror corresponding to the first current is connected in; the source electrode of each PMOS transistor is connected in parallel and grounded; the drain electrode 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 connected with the summing node; correspondingly, the grid electrode of each NMOS transistor is connected in parallel, and the mirror voltage of the current mirror corresponding to the second current is accessed; the source electrode of each NMOS transistor is connected in parallel and grounded; the drain electrode of each NMOS transistor is connected with one end of a switch respectively, and the other end of each switch is connected in parallel and connected with the summing node.

According to the present invention, there is provided an adaptive range switching temperature sensor, the current generating circuit comprising: the first PNP triode, the second PNP transistor, the first resistor, the second resistor, the third resistor and the fourth resistor, the first operational amplifier, the second capacitor and the fourth PMOS transistor, the fifth PMOS transistor, the sixth PMOS transistor, the fourth NMOS transistor, the fifth NMOS transistor and the sixth NMOS transistor, wherein: the base electrode of the first PNP triode is connected with the collector electrode of the first PNP triode, the base electrode 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 grounded; the emitter of the first PNP triode is connected with 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 electrode 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 electrode of the fourth NMOS transistor is connected with the drain electrode of the fourth PMOS transistor, the grid electrode of the fourth PMOS transistor and the grid electrode of the fifth PMOS transistor; the source electrode of the fourth NMOS transistor is connected with the source electrode of the fifth PMOS transistor and the source electrode of the sixth PMOS transistor and is connected with a power supply; the drain electrode of the fifth PMOS transistor is connected with the drain electrode of the fifth NMOS transistor and the grid electrode 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 electrode 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 present invention, there is provided an adaptive range switching temperature sensor, the counter circuit comprising: the counting module, the timing module and the output indication module; the counting module is used for receiving the bit stream signal and quantizing the duty ratio information in the bit stream signal 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 measured 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 measurement result is output.

According to the self-adaptive range switching temperature sensor provided by the invention, the range of the temperature sensor can be automatically refined and switched by refining and splitting the large temperature measurement range interval and matching with the corresponding modulator circuit and the range control circuit, so that 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 invention or the technical solutions of the prior art, the following description will briefly explain the drawings used in the embodiments or the description of the prior art, and it is obvious that the drawings in the following description are some embodiments of the invention, and other drawings can be obtained according to the drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic diagram of a self-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 diagram of a manual range switching temperature sensor according to 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 of the principle of range refinement in the adaptive range switching temperature sensor provided by the invention;

FIG. 6 is a schematic flow chart of the detection and control function implemented by the range control circuit in the adaptive range switching temperature sensor provided by the invention;

FIG. 7 is a schematic diagram of a current generating 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 as follows:

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 synchronizing circuit; 401: a counting module; 402: a timing module;

403: and outputting an indication module.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings, and it is apparent that the described embodiments are some embodiments of the present invention, not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

The adaptive span switching temperature sensor provided by the embodiments of the present invention is described below with reference to fig. 1-9.

FIG. 1 is a schematic diagram of a self-adaptive range-switching temperature sensor according to the present invention, as shown in FIG. 1, including but not limited to: current generation circuit 100, span switching circuit 200, modulator circuit 300, counter circuit 400, and span control circuit 500.

The current generating 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 converted 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 prior art temperature sensor, as shown in fig. 2, which includes: a current generation 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 fixed-range temperature sensor, and the duty ratio of the generated bit stream signal corresponds to the temperature one by one. 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 needed to be made corresponding to different applications, different batches of flow sheets are carried out, the designed manpower resources are wasted, and the flow sheet cost is increased.

Fig. 3 is a schematic structural view of a manual range switching temperature sensor according to the present invention, and as shown in fig. 3, the present invention provides a temperature sensor capable of manually implementing range switching based on the prior art. The working principle comprises the following steps: by performing a combined operation on the measurement current generated by the temperature generating circuit 100, the measurement range switching circuit 200 is used to perform a conversion of the measurement range on the measurement current, so as to generate a conversion current corresponding to the measurement range, thereby changing the magnitude of the current flowing into the modulator circuit 300, and realizing the switching of the measurement range.

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 of an analog circuit by adopting the oversampling, noise shaping and digital filtering technology, and realizes high precision and low power consumption which cannot be achieved by other types of ADCs.

The range switching circuit 200 converts the detected temperature to be measured into a corresponding measurement current through the temperature sensing element.

Alternatively, the measured current may include 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; alternatively, a part of the current may be a current proportional to the absolute temperature corresponding to the temperature to be measured or a current inversely proportional to the absolute temperature corresponding to the temperature to be measured, and the other part may be a reference current (such as a constant direct current). That is, in the above-mentioned temperature sensor manually implementing range switching, the measurement 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 a current output terminal of the current generating circuit 100, and is configured to receive 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, outputs a corresponding conversion current after performing a combination operation on the received measurement current.

Further, the output of the span switching circuit 200 is connected to the input of the modulator circuit 300. The modulator circuit 300 modulates (mainly includes analog-to-digital conversion) the received converted current, 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 higher the high level duty cycle acquired in one sampling period, the higher the corresponding temperature to be measured.

Further, in order to accurately implement temperature measurement and reading, the adaptive range switching temperature sensor provided by the present invention further includes a counter circuit 400, where an input end of the counter circuit 400 is connected to an output end of the modulator circuit 300, and is used for quantizing an input bit stream signal and outputting a binary signal containing the temperature information. Finally, the binary signal is converted into a corresponding measurement result to be output.

It should be noted that, the current generating circuit 100, the modulator circuit 300 and the counter circuit 400 may be all circuits commonly used in the prior art to perform corresponding functions, which is not described in detail herein.

Compared with the prior art, the self-adaptive range switching temperature sensor provided by the invention is characterized by further comprising a range switching circuit 200, wherein the range switching circuit can correspondingly convert the measured current output by the current generating circuit 100 according to different temperature measuring ranges according to a bit stream control signal and a range control vector signal, and can realize the switching of the temperature measuring ranges by changing the magnitude of the current flowing into a modulator circuit.

Wherein the bit stream control signal is determined by the bit stream signal output by the modulator circuit 300 in the last sampling period to determine that the span switching circuit 200 is in a reset state in the current sampling period based on the last sampling period bit stream signal.

For example, at the end of the previous sampling period, the bit stream signal is at a high level, and the elements for current conversion corresponding to the bit stream signal are the switch SW1 and the switch SW2 respectively; then switch SW1 is first adjusted to open and switch SW2 is closed according to the bit stream control signal in the current sampling period.

The range control vector signal can be provided by an external input, such as a peripheral signal generator, and the working states of all elements in the range switching circuit are changed to realize equal-proportion conversion of the measured current according to different temperature measuring ranges and output corresponding conversion current.

Because of the variable range temperature sensor capable of manually realizing range switching, the principle of switching into a proper range to realize temperature measurement is that the current source is connected into the access combination according to the actual application scene. Under the condition of larger temperature fluctuation range or higher requirement on temperature measurement precision, the whole large measuring range is split by using a plurality of interval measuring ranges to realize measuring range switching measurement, which needs to be manually configured according to the measured environmental temperature change, including manually judging whether the subdivided measuring range switched to currently is the measuring range capable of accurately measuring the temperature or not, and adjusting the configuration of a measuring range switching circuit through step-by-step judgment, so that the measuring time and the complexity degree are increased.

In view of this, the adaptive range switching temperature sensor provided by the present invention adds a range control circuit 500 on the basis of the variable range temperature sensor for manually implementing range switching. The span control circuit 500 has an input connected to the output of the counter circuit 400 to receive the binary signal generated by the counter circuit 400 and record the Nbit binary number within a predetermined sampling period.

Further, the range control circuit 500 determines whether the temperature to be measured can be accurately determined under the current range according to the N bit binary number. If the temperature to be measured cannot be accurately read according to the N bit binary number, outputting a group of measurement 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 range switching circuit is not required to be controlled to perform range switching, and the measurement result of the temperature to be measured is directly output according to the binary signal output by the counter circuit 400.

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 large wide range measurement range and high small range measurement 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; furthermore, 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 refinement switching by refining and splitting a large temperature measurement range interval and matching with a corresponding modulator circuit and a range control circuit, and automatically find a high-precision range matched with the current measured temperature to realize high-precision measurement.

Based on the foregoing embodiments, as an alternative embodiment, in the case where the measured current includes a first current and a second current different from the first current, the span switching circuit 200 includes: a first current mirror group formed by m parallel current mirrors and a second current mirror group formed by n parallel current mirrors, wherein each current mirror is connected with a summation 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 by the present invention, as shown in fig. 4, in the adaptive range switching temperature sensor provided by 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 invention mainly comprises a series of current mirrors and corresponding path switches, wherein the current mirrors mirror currents inversely proportional to absolute temperature and proportional to absolute temperature in the current generating circuit 100, and the mirror proportion size is calculated according to the required range. Assuming that a current inversely proportional to absolute temperature is abbreviated as i_be, a current directly proportional to absolute temperature is abbreviated as i_ptat, in the range switching circuit 200, a current of a multiple of i_ptat flows through the lower half current mirror, and a current of a multiple of i_be flows through the upper half current mirror.

The current mirror is also called mirror constant current source, and is used to generate bias current and as active load, and is a common standard component in analog integrated circuit.

Specifically, in the adaptive range switching temperature sensor provided by the present invention, a first current mirror group is formed by connecting m current mirrors in parallel, as shown in I in fig. 4 ₁ 、I ₃ 、I ₅ 、I ₇ …I _n The method comprises the steps of carrying out a first treatment on the surface of the Simultaneously connecting n current mirrors in parallel to form a second current mirror group, such as I in FIG. 4 ₂ 、I ₄ 、I ₆ 、I ₈ …I _m . Each current mirror can be regarded as a current source proportional to the input current (i.e. current transfer ratio), and therefore, each current mirror is 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 according to the reference numerals of fig. 4. Wherein each current source is connected via a switch to a summing node, which is connected to an input of the modulator circuit 300.

Further, the parallel intersection of all current sources in the first current mirror group is connected to the first current (i_ptat) in the measurement current, and the parallel intersection of all current sources in the second current mirror group is connected to the first current (i_be) in the measurement current. On this basis, all current sources of the first current mirror group are used to charge the summing node according to the input i_ptat; all current sources of the second current mirror group are used to discharge to the summing node according to the input i_be.

Finally, the modulator circuit outputs a corresponding bit stream signal from the received measurement current (the measurement current may be determined by combining i_ptat and i_be generated by the current generating circuit).

The range switching circuit provided by the invention can realize the conversion of the measured current, and is mainly characterized in that: the on-off control of each switch can be realized according to the bit stream control signal and the range control vector signal, so as to control the on-off between each current source and the summing node, further control the magnitude of the conversion current input to the modulator circuit 300, and realize the switching of the range.

The self-adaptive range switching temperature sensor provided by the invention utilizes a plurality of current mirrors to form a current mirror group, and realizes the adjustment of the input measured current by controlling the output of each current mirror current to the modulator circuit or not.

Based on the foregoing embodiments, as an optional embodiment, the first current mirror group includes at least one first current mirror with a mirror ratio size of 1, the second current mirror group includes at least one second current mirror with a mirror ratio size of 1, and the 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 proportion size of 1, the second current mirror group at least comprises a fourth current mirror with the mirror proportion size of 1, and the bit stream control signal is used for controlling the switches corresponding to the third current mirror and the fourth current mirror; the range control vector signal is used for controlling the switches corresponding to the current mirrors except the first current mirror, the second current mirror, the third current mirror and the fourth current mirror.

Based on the above embodiments, as an alternative embodiment, a first current mirror I with a mirror ratio size of 1 may be selected ₁ Second current mirror I ₂ Third current mirror I ₃ And a fourth current mirror I ₄ Wherein the first current mirror I ₁ And a second current mirror I ₃ Is the same as the current direction of the second current mirror I ₂ And a fourth current mirror I ₄ The current direction of (2) is opposite.

Wherein, the first current mirror I ₁ Second current mirror I ₂ The corresponding switch is in a normally-closed state, and the third current mirror I ₃ Fourth current mirror I ₄ The corresponding switch states are opposite, i.e. in the fourth current mirror I ₄ When the corresponding switch is closed, the third current mirror I ₃ The corresponding switch is opened; at the fourth current mirror I ₄ When the corresponding switch is opened, the third current mirror I ₃ The corresponding switch is closed.

Specifically, the switches corresponding to the third current mirror and the fourth current mirror are controlled by two opposite signals, and the signals are the output bit_stream of the sigma-delta modulator circuit; the switches corresponding to the first current mirror and the second current mirror are normally closed in the invention. The switches corresponding to the first current mirror, the second current mirror, the m current mirror and the n current mirror are controlled by a control vector, the control vector is a range switching control signal, and when the switches corresponding to the fifth current mirror, the sixth current mirror, the m current mirror and the n current mirror are connected into a current summation node after the switches corresponding to the fifth current mirror, the sixth current mirror, the m current mirror and the n current mirror are controlled to be closed according to vector combination, the number of the third current mirror, the fourth current mirror and the current combination operation formula is equivalently changed, so that the switching of the range is realized. The range control vector of the embodiment realizes different range control by controlling the switch corresponding to the fifth current mirror to the switch corresponding to the mth current mirror and the nth current mirror.

In the case where i_ptat charges the summing node and i_be discharges the summing node, the duty cycle of the bitstream signal is calculated as:

wherein k is ₁ Is the sum of the mirror scale dimensions of all current mirrors charging the summing node, k ₂ Is the sum of the mirror scale dimensions of all current mirrors discharging to the summing node.

Therefore, the self-adaptive range switching temperature sensor provided by the invention is realized through the first current mirror I ₁ Second current mirror I ₂ Third current mirror I ₃ And a fourth current mirror I ₄ The corresponding switch can acquire the reference duty ratio by adopting the setting, so that the calibration operation of the whole self-adaptive range switching temperature sensor can be conveniently realized according to the reference duty ratio in the later period.

Fig. 5 is a schematic diagram of a range refinement principle in the adaptive range switching temperature sensor provided by the invention, as shown in fig. 5, a waveform in a left graph is a temperature duty ratio corresponding curve (a horizontal axis is temperature and a vertical axis is duty ratio) with a wide range, a temperature range of-40-125 ℃ corresponds to 10% -90% of duty ratio change, and a 1% of duty ratio change corresponds to about 2 ℃ of temperature change. The waveforms in the right graph are temperature duty cycle correspondence curves after refining the span, dividing the entire wide span into about 5 refined sub-spans, each sub-span being able to quantify the temperature within the span with a 10% -90% duty cycle, thus improving the accuracy of the wide span by about 5 times compared to that shown in the graph. According to the self-adaptive range switching temperature sensor provided by the embodiment of the invention, the range control vector signal can be automatically generated by the range control circuit 500 based on the binary signal output by the counter circuit 400, so that the switch of each current mirror is controlled in a combined way, and the automatic refined switching of the range is realized.

Optionally, during the process of performing range subdivision, a preset proportion (for example, 10%) of overlap may be set between every two adjacent sub-ranges, so as to avoid the increase of sampling errors of the subsequent circuits during the low duty cycle.

Further, in order to enable 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 measuring range control scheme is a scheme for controlling the switching state of each current mirror according to different measuring ranges; based on the temperature measuring sequence corresponding to the measuring range of each measuring range control scheme, each measuring range control scheme sequentially corresponds to different measuring range control gears.

As shown in fig. 5, a control scheme for dividing the wide range into 5 sub-ranges can be calculated in advance, and as shown in fig. 4, it is assumed that the switch states corresponding to the original wide range are switch SW1 closed, switch SW2 closed, switch SW3 open, switch SW4 closed, and all other switches SW5-SWn open. When the wide range is divided into sub-ranges corresponding to the curve C, the corresponding switch states are as follows: the switches SW1 are closed, SW2 are closed, SW3 are open, SW4 are 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: the switches SW1 are closed, SW2 are closed, SW3 are open, SW4 are closed, SW5-SW8 are closed, and 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 as follows: the switches SW1 are closed, SW2 are closed, SW3 are open, SW4 are closed, SW5-SW10 are closed, and 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 as follows: the switches SW1 are closed, SW2 are closed, SW3 are open, SW4 are closed, SW5-SW12 are closed, and 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: the switches SW1 are closed, SW2 are closed, SW3 are open, SW4 are closed, SW5-SW14 are closed, and 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: the switches SW1 are closed, SW2 are closed, SW3 are open, SW4 are closed, SW5-SW16 are closed, and 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: the switches SW1 are closed, SW2 are closed, SW3 are open, SW4 are closed, SW5-SW18 are closed, and all other switches SW19-SWn are open.

Then the scheme of controlling the switching state of each current mirror according to each different measuring range (each sub-measuring range corresponding to the curve E-curve N) is used as a measuring range control scheme. Optionally, the number may be given according to the temperature measurement sequence corresponding to the measuring range, for example: and sequentially numbering the range control schemes corresponding to the curves E-N as a control scheme 1-6, and further taking each sub-range as one range control gear according to the sequence of the numbers, so that the corresponding range control gears can be selected according to different range control vector signals.

According to the self-adaptive range switching temperature sensor provided by the invention, 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 under the current range can be judged according to the analysis result, and under the condition that the reading error is large, the corresponding range control vector signal can be automatically generated, and the corresponding range control scheme is called through the range control vector signal, so that the range switching is realized by the range switching circuit, the range switching can be effectively and autonomously realized, and the measurement accuracy is improved.

FIG. 6 is a schematic flow chart of the invention for implementing detection and control functions by the range control circuit in the adaptive range switching temperature sensor, as shown in FIG. 6, the range control circuit generates the range control vector signal according to the binary signal, and specifically includes:

the range control circuit acquires binary data in the binary signal; generating a range down shift control vector signal in case it is determined that the binary data are all 0; generating a range upshift control vector signal in the case where it is determined that the binary data are all 1; the range down shift control vector signal is a signal related to a range control scheme corresponding to the next range control gear which is called from a range control scheme storage module; the range upshift control vector signal is a signal related to a range control scheme corresponding to a last range control gear which is called from a range control scheme storage module.

Specifically, the range control circuit 500 provided by the present invention is configured to collect and analyze the N bit binary number output by the counter circuit 400, so as to implement switching of the range through the range switching circuit 200. Taking the wide-range subdivision scheme shown in fig. 5 as an example, the following description will be given:

Assuming that the current range is a sub-range corresponding to the curve G, when the obtained N bit binary numbers are all 0, it is indicated that the current range is higher, the actual temperature value is lower than the current range, the control range is measured again after being lowered by one step, 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 continues the normal temperature measurement.

Further, if the obtained N bit binary number after switching is still 0, the current measuring range is continuously switched from the sub-measuring range corresponding to the curve E to the sub-measuring range corresponding to the curve C until the obtained N bit binary number is not all 0, the measuring range switching is proved to be completed, and normal temperature measurement is started.

Assuming that the current range is a sub-range corresponding to the curve G, if the obtained N bit binary number is not all 0, then judging whether all 1. If the current range is 1, the current range is lower, the actual temperature value is higher than the current range, the control range is measured again after being higher by one grade, specifically, the range is switched from the sub-range corresponding to the curve G to the sub-range corresponding to the curve J, the range switching is sequentially carried out by the method until the acquired Nbit binary number is not 0, the range switching is proved to be finished, and the normal temperature measurement is started.

Further, the span control circuit generates the span control vector signal according to the binary signal, and further includes:

the measuring range control circuit judges whether the temperature corresponding to the binary signal is in a preset range of the current measuring range or not under the condition that the binary data are not all 0 and not all 1; and if the range is not within the preset range, generating a range down shift control vector signal.

For example, assuming that the current range is a sub-range corresponding to the curve G, if the obtained N bit binary number is 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 ratio interval (generally set to 20% -90%) capable of accurately measuring temperature; correspondingly, the duty cycle interval of 10% -20% is the interval with the risk of increasing sampling errors.

If not, i.e. the value is in the interval where there is a risk of increased sampling errors, requiring a first gear range reduction. By arranging the overlapping area (about 10%) between different measuring ranges, the invention is beneficial to improving the sampling precision because the actual temperature is in a large duty ratio area of a low measuring range after the measuring range is reduced. If the value is in the preset interval, the interval at the moment is a proper measuring range interval, and 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 be sampled in practice, for example, whether the N bit binary data is all 1 is determined first, and then whether the N bit binary data is all 0 is determined.

The invention provides a self-adaptive range switching temperature sensor, which correspondingly generates corresponding range control vector signals according to binary data output by a counter circuit, so as to automatically realize the matching of ranges according to the current temperature measurement requirement, and can refine and split a large temperature measurement range.

Meanwhile, the self-adaptive range switching temperature sensor provided by the invention has the advantages that the range switching circuit and the range control circuit are arranged, so that the increase of the chip area is extremely small, the application scene of the temperature sensor chip is expanded at extremely low cost, the automation and self-adaptive degree of the temperature measuring chip are improved, and the time cost during temperature measurement is also saved.

Based on the foregoing embodiments, as an alternative embodiment, the m parallel current mirrors that form the first current mirror group are PMOS transistors; n parallel current mirrors forming the second current mirror group are NMOS transistors;

the grid electrode of each PMOS transistor is connected in parallel, and the mirror voltage of the current mirror corresponding to the first current is connected in; the source electrode of each PMOS transistor is connected in parallel and grounded; the drain electrode 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 connected with the summing node;

correspondingly, the grid electrode of each NMOS transistor is connected in parallel, and the mirror voltage of the current mirror corresponding to the second current is accessed; the source electrode of each NMOS transistor is connected in parallel and grounded; the drain electrode of each NMOS transistor is connected with one end of a switch respectively, and the other end of each switch is connected in parallel and connected with the summing node.

In the adaptive range switching temperature sensor provided by the invention, for a range switching circuit 200, the adaptive range switching temperature sensor mainly comprises a series of PMOS and NMOS transistors and corresponding switches, wherein the transistors are current mirrors, the mirror images are obtained by calculating the current I_ptat which is inversely proportional to absolute temperature and the current I_be which is directly proportional to absolute temperature in a current generating circuit 100 according to the required range. In the range switching circuit 200, the NMOS transistor flows a multiple current of i_ptat, and the PMOS transistor flows a multiple current 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 is the output Bit Stream signal bit_stream of the sigma-delta modulator circuit 300. The third switch SW3 and the fourth switch SW4 are in an on state in the present invention; the fifth switch SW5 and the sixth switch SW6 to the m switch SWm and the n switch SWn are controlled by a range control vector signal, which is a range switching control signal, and when the fifth switch and the sixth switch to the m switch and the n switch are closed according to vector combination control, the fifth current mirror PMOS3 and the sixth current mirror NMOS3 to the m current mirror and the n current mirror access to the current summation node, which can be equivalent to changing the number of the third current mirror PMOS2 and the fourth current mirror NMOS2 and equivalent to changing the current combination operation formula, thereby realizing the switching of the range.

As a specific embodiment, in the range switching circuit, the mirror proportion size of the first PMOS transistor is 1, the mirror proportion size of the second PMOS transistor is 1, the mirror proportion size of the third PMOS transistor is 5, the mirror proportion size of the first NMOS transistor is 1, the mirror proportion size of the second NMOS transistor is 1, the mirror proportion size of the third NMOS transistor is 6, the mirror proportion sizes are calculated according to the range of-40 to 125 ℃ and the range of 20 to 50 ℃, and the duty ratio formulas corresponding to the two temperature measurement ranges are as follows:

It can be seen that the denominator i_ptat+i_be is a current independent of temperature, the molecular combination is a value related to temperature, and the duty ratios obtained by different combination operations are different, so that different application ranges are realized.

Based on the principle analysis described above, it should be understood by those skilled in the art that different design ranges may correspond to different combination operation modes, in the embodiment, only switching between two specific ranges is illustrated, and in practical application, multiple 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 proportion sizes of the m+n current mirrors are fixed, but in other measuring range applications, different current mirror proportions may be adopted to implement different combination operations according to actual calculation requirements, and the various current mirror proportions are included in the protection scope of the present invention, that is, the present invention does not specifically limit the mirror proportion 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 and 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 NMOS6.

The base electrode of the first PNP triode PNP1 is connected to the collector electrode of the first PNP triode PNP1, the base electrode of the second PNP triode PNP2, the collector electrode of the second PNP triode PNP2, one end of the second capacitor C2, the source electrode of the fifth NMOS transistor NMOS5, and one end of the fourth resistor R4, and grounded;

the emitter of the first PNP triode PNP1 is connected with 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 grid NMOS4 of the fourth NMOS transistor;

the source electrode of the fourth NMOS transistor NMOS4 is connected to 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;

the drain electrode of the fourth NMOS transistor NMOS4 is connected to the drain electrode of the fourth PMOS transistor PMOS4, the gate electrode of the fourth PMOS transistor PMOS4, and the gate electrode of the fifth PMOS transistor PMOS 5;

the source electrode of the fourth NMOS transistor NMOS4 is connected with the source electrode of the fifth PMOS transistor PMOS5 and the source electrode of the sixth PMOS transistor PMOS6, and is connected with a power supply;

The drain electrode of the fifth PMOS transistor PMOS5 is connected with the drain electrode of the fifth NMOS transistor NMOS5 and the grid electrode 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 op-amp 102;

the source electrode 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 op-amp 102;

the positive input end of the second operational amplifier 102 is connected to the emitter of the second PNP transistor PNP2 and the other end 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 combined by 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 according to 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 integrating circuit, one end of the first capacitor C1 is connected to the negative input end of the third operational amplifier 301, the other end of the first capacitor C1 is connected to the output end of the third operational amplifier 301 and the negative input end of the comparator 302, and the positive input end 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 the threshold voltage VTH of the comparator;

the output end of the comparator 302 is connected to the synchronization circuit 303, and the synchronization circuit 303 is configured to generate the Bit Stream signal bit_stream according to a comparison result of the comparator 302 output in a system clock period.

It should be noted that, the present invention provides a sigma-delta modulator circuit, alternatively, other modulator circuits may be used, where other modulator circuits may be appropriately changed in structure according to actual usage, essentially, the combined current needs to be integrated by an integrator, and then compared by a comparator, a Bit Stream signal bit_stream with a duty ratio including temperature information is output, and the synchronization circuit 303 is used to generate the Bit Stream signal bit_stream synchronously by using a system clock, so as to facilitate subsequent count quantization by using the counter circuit 400, so as to reduce sampling errors.

Fig. 9 is a schematic structural diagram of a counter circuit according to 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 bit stream signal and quantize the duty ratio information in the bit stream signal to output binary data corresponding to the measurement result of the temperature to be measured; the timing module 402 is mainly configured to control a time period for converting the measured current, and control 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 the bit stream information output by the pre-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 count duration of the counting module 401.

The output indication module 403 is configured to inform the later stage that the output is ready after counting, 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, in the counter circuit 400 provided in the present invention, as a specific embodiment, other counter circuits may be adopted, and the structure of the other counter circuits may be changed according to the actual use situation, for example, if the number of output bits is required to be changed based on the circuit structure shown in fig. 9, the timing duration may be changed accordingly, etc.

Based on the foregoing embodiment, as an alternative 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 the I_ptat which is in direct proportion to the absolute temperature corresponding to the temperature to be detected and the I_be which is in inverse proportion to the absolute temperature corresponding to the temperature to be detected by utilizing the current generating circuit 100, so that the range switching circuit 200 is conveniently utilized in the later stage, the range control vector signal is reasonably configured according to the temperature measuring range, the input current is modulated to generate the measuring current, and the accuracy of range switching is effectively improved.

Based on the foregoing embodiment, as an alternative embodiment, the bit stream control signal is determined according to a high-low level state of the bit stream signal; the bit stream control signal is used for controlling the switches corresponding to the third current mirror and the fourth current mirror, and specifically comprises: 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 opened and controls the switch corresponding to the fourth current mirror to be closed; correspondingly, when the bit stream signal acquired 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 provided by the invention, on the basis of realizing the configuration of a range switching circuit by using a range control vector signal, a bit stream control signal is generated according to the high-low level state of a bit stream signal, so that the generated test quantity current is rectangular wave current, a basis is provided for the post-counter circuit to quantize the duty ratio of the bit stream signal, and the measurement precision is effectively improved.

In summary, the self-adaptive range switching temperature sensor provided by the invention creatively provides a range switching circuit to be matched 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 groups of temperature measuring ranges under the condition of no power failure. The design mode has extremely small increase of the chip area, expands the application scene of the temperature sensor chip at extremely low cost, improves the chip integration level and saves the cost of multi-version differentiation increase.

The apparatus embodiments described above are merely illustrative, wherein the elements illustrated as separate elements may or may not be physically separate, and the elements shown as elements may or may not be physical elements, may be located in one place, or may be distributed over a plurality of network elements. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of this embodiment. Those of ordinary skill in the art will understand and implement the present invention without undue burden.

From the above description of the embodiments, it will be apparent to those skilled in the art that the embodiments may be implemented by means of software plus necessary general hardware platforms, or of course may be implemented by means of hardware. Based on this understanding, the foregoing technical solution may be embodied essentially or in a part contributing to the prior art in the form of a software product, which may be stored in a computer readable storage medium, such as ROM/RAM, a magnetic disk, an optical disk, etc., including several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute the various embodiments or some parts of the embodiments.

Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present invention, and are not limiting; although the 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 scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An adaptive span 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 generation circuit is used for generating a measurement current according to the temperature to be measured;

the measuring range switching circuit is used for converting the measuring current according to a bit stream control signal and a measuring range control vector signal to generate a converted current;

the modulator circuit is used for carrying out analog-digital modulation on the converted 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 the range control vector signal according to the binary signal;

in the case where the measured current includes a first current and a second current different from the first current, the range switching circuit includes:

a first current mirror group formed by m parallel current mirrors and a second current mirror group formed by n parallel current mirrors, wherein each current mirror is connected with a summation 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 with the input end of the modulator circuit;

the range control circuit at least comprises a range control scheme storage module for storing 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;

based on the temperature measuring sequence corresponding to the measuring range of each measuring range control scheme, each measuring range control scheme sequentially corresponds to different measuring range control gears;

the range control circuit generates the range control vector signal according to the binary signal, and specifically includes:

the range control circuit acquires binary data in the binary signal;

generating a range down shift control vector signal if it is determined that all of the binary data are 0;

generating a span upshift control vector signal in the case where it is determined that the binary data are all 1;

the range down shift 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 range control scheme-related signal corresponding to the last range control gear which is called from the range control scheme storage module;

the range control circuit generates the range control vector signal according to the binary signal, and further comprises:

the measuring range control circuit judges whether the temperature corresponding to the binary signal is in a preset range of the current measuring range or not under the condition that the binary data are not all 0 and not all 1;

and if the range is not within the preset range, generating a range down shift control vector signal.

2. The adaptive range-switching temperature sensor of claim 1, wherein,

the first current mirror group at least comprises a first current mirror with the mirror proportion size of 1, the second current mirror group at least comprises a second current mirror with the mirror proportion size of 1, and the 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 proportion size of 1, and the second current mirror group at least comprises a fourth current mirror with the mirror proportion size of 1;

The bit flow control signal is used for controlling the switches corresponding to the third current mirror and the fourth current mirror;

the range control vector signal is used for controlling the switches corresponding to the current mirrors except the first current mirror, the second current mirror, the third current mirror and the fourth current mirror.

3. The adaptive range-switching temperature sensor of claim 1, wherein the m parallel current mirrors comprising the first current mirror group are PMOS transistors; n parallel current mirrors forming the second current mirror group are NMOS transistors;

4. The adaptive range-switching temperature sensor of claim 1, wherein the current generation circuit comprises: the first PNP triode, the second PNP transistor, the first resistor, the second resistor, the third resistor and the fourth resistor, the first operational amplifier, the second capacitor and the fourth PMOS transistor, the fifth PMOS transistor, the sixth PMOS transistor, the fourth NMOS transistor, the fifth NMOS transistor and the sixth NMOS transistor, wherein:

the base electrode of the first PNP triode is connected with the collector electrode of the first PNP triode, the base electrode 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 grounded;

the emitter of the first PNP triode is connected with 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 electrode 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 electrode of the fourth NMOS transistor is connected with the drain electrode of the fourth PMOS transistor, the grid electrode of the fourth PMOS transistor and the grid electrode of the fifth PMOS transistor;

the source electrode of the fourth NMOS transistor is connected with the source electrode of the fifth PMOS transistor and the source electrode of the sixth PMOS transistor and is connected with a power supply;

the drain electrode of the fifth PMOS transistor is connected with the drain electrode of the fifth NMOS transistor and the grid electrode 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 electrode 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.

5. 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.

6. The adaptive range-switching temperature sensor of claim 1, wherein the counter circuit comprises: the counting module, the timing module and the output indication module;

the counting module is used for receiving the bit stream signal and quantizing the duty ratio information in the bit stream signal 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 measured 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 measurement result is output.