Analog-to-digital conversion circuit of a temperature sensor
By combining coarse and fine quantization adjustment modules with the principle of charge conservation, the analog-to-digital conversion circuit of the temperature sensor is simplified, resolving the contradiction between conversion time and accuracy, and achieving efficient and low-cost temperature detection.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- SMARTSENS TECH (SHANGHAI) CO LTD
- Filing Date
- 2022-06-09
- Publication Date
- 2026-06-05
AI Technical Summary
Existing analog-to-digital conversion circuits increase conversion time when improving resolution and accuracy, leading to a decrease in the conversion efficiency of temperature sensors.
By employing coarse and fine quantization adjustment modules, multiple temperature adjustments are achieved through negative correlation voltage and positive correlation current. The coarse and fine quantization values of temperature are determined by combining the principle of charge conservation, simplifying the circuit structure and reducing the number of electronic components.
While improving conversion efficiency, it maintains high-precision quantization, with simple circuitry, small footprint, and low cost.
Smart Images
Figure CN117254815B_ABST
Abstract
Description
Technical Field
[0001] This application belongs to the field of temperature sensor technology, and particularly relates to an analog-to-digital conversion circuit for a temperature sensor. Background Technology
[0002] A temperature sensor is a sensor that can detect ambient temperature and convert it into a usable signal output. A temperature sensor generally includes a front-end detection circuit and an analog-to-digital converter circuit. The front-end detection circuit detects the ambient temperature and generates an analog temperature signal, while the analog-to-digital converter circuit converts the analog temperature signal into a digital temperature signal for output.
[0003] Existing analog-to-digital converter circuits generally use Sigma-delta (ΣΔ) analog-to-digital converters to quantize temperature gain, which can achieve high resolution and accuracy, but also increases the quantization time accordingly, which is detrimental to the conversion efficiency of temperature sensors. Summary of the Invention
[0004] The purpose of this application is to provide an analog-to-digital conversion circuit for a temperature sensor, which aims to solve the problem of traditional analog-to-digital conversion circuits trading conversion time for resolution and accuracy.
[0005] To achieve the above objectives, in a first aspect, embodiments of this application provide an analog-to-digital conversion circuit for a temperature sensor, including a coarse quantization adjustment module, a fine quantization adjustment module, a comparison module, and a control module;
[0006] The temperature sensor is configured to determine, based on a bipolar transistor, a negatively correlated voltage and a negatively correlated current that are negatively correlated with temperature, and a positively correlated current that is positively correlated with temperature.
[0007] The coarse quantization adjustment module is configured to output a current that is a multiple of the positively correlated current according to an initial coarse quantization control signal, and adjust the multiple relationship according to an intermediate coarse quantization control signal to finally obtain a coarse quantization current, so as to obtain a coarse quantization voltage based on the coarse quantization current.
[0008] The fine-tuning module is configured to obtain a fine-tuning current based on the fine-tuning control signal and the positively correlated current;
[0009] The comparison module is configured to convert the output current of the coarse quantization adjustment module into the output voltage of the coarse quantization adjustment module, and compare the output voltage of the coarse quantization adjustment module with the negative correlation voltage to obtain a comparison signal;
[0010] The control module is configured to output a preset initial coarse quantization control signal and determine the intermediate coarse quantization control signal based on the comparison signal, so as to determine the coarse quantization value of the temperature based on the coarse quantization voltage.
[0011] It is also configured to generate the fine quantization control signal based on the coarse quantization value of the temperature; and to determine the fine quantization value of the temperature based on the fine quantization current and charge conservation principle.
[0012] The beneficial effects of this application embodiment compared with the prior art are as follows: The analog-to-digital conversion circuit of the temperature sensor above determines the coarse quantization voltage by adjusting the coarse quantization control signal of the coarse quantization adjustment module multiple times, so as to determine the coarse quantization value of the temperature based on the coarse quantization voltage, and determines the fine quantization current by the fine quantization adjustment module, so as to determine the fine quantization value of the temperature based on the fine quantization current and the principle of charge conservation. The circuit is simple, occupies a small area, and has low cost, and maintains high quantization accuracy while improving conversion efficiency. Attached Figure Description
[0013] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0014] Figure 1 This is a schematic diagram of the analog-to-digital conversion circuit of the temperature sensor provided in an embodiment of this application;
[0015] Figure 2 A circuit diagram of the analog-to-digital conversion circuit of the temperature sensor provided in an embodiment of this application;
[0016] Figure 3 A coarse-quantization flowchart of the analog-to-digital conversion circuit of the temperature sensor provided in the embodiments of this application;
[0017] Figure 4 A first circuit diagram of a fine-grained control unit for the analog-to-digital conversion circuit of a temperature sensor provided in an embodiment of this application;
[0018] Figure 5 A second circuit diagram of a fine-tuning control unit for the analog-to-digital conversion circuit of a temperature sensor provided in an embodiment of this application.
[0019] Explanation of reference numerals in the attached figures:
[0020] 1-Coarse quantization adjustment module, 2-Fine quantization adjustment module, 3-Quantization module, 4-Control module, 41-Coarse quantization control unit, 42-Fine quantization control unit. Detailed Implementation
[0021] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.
[0022] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.
[0023] The front-end detection circuit typically detects the negative correlation voltage V between two bipolar transistors that is negatively correlated with temperature. BE1 With V BE2 The positively correlated voltage ΔV with temperature was obtained. BE =V BE1 -V BE2 The negative correlation voltage V BE1 Positively correlated voltage ΔV BE The weighted sums yield a temperature-independent reference voltage V. REF =V BE1 +α·ΔV BE According to α·ΔV BE With reference voltage V REF The ratio of the two values yields the temperature gain. That is, μV BE1 = (1-μ)α·ΔV BE According to the law of conservation of charge, V BE1 ·T2=α·△V BE ·T1, and substitute it into get Where μ can be regarded as a digital quantity positively correlated with temperature, then 1-μ can be regarded as a digital quantity negatively correlated with temperature.
[0024] A linear transformation is performed on the temperature gain μ to fit a straight line T = A·μ + B, where A and B are fixed constants, typically A ≈ 620 and B ≈ -280. In practical applications, only the value of μ is needed to determine the current temperature. However, existing analog-to-digital converters involve a large amount of quantization work during the analog-to-digital conversion process, resulting in low quantization efficiency.
[0025] This application provides an analog-to-digital conversion circuit for a temperature sensor. It achieves coarse and fine quantization processes by using a negatively correlated voltage and current that are negatively correlated with temperature, and a positively correlated current that is positively correlated with temperature. This reduces the number of electronic components such as capacitors and resistors, resulting in a simple circuit with a small footprint and low cost. Furthermore, it maintains high quantization accuracy while improving conversion efficiency.
[0026] The gain adjustment circuit of the temperature sensor provided in this application will be described in illustrative form below with reference to the accompanying drawings.
[0027] Figure 1 This is a schematic diagram of the gain adjustment circuit of the temperature sensor provided in an embodiment of this application. Figure 1 As shown, exemplarily, a gain adjustment circuit 100 for a temperature sensor includes a coarse quantization adjustment module 1, a fine quantization adjustment module 2, a comparison module 3, and a control module 4.
[0028] A temperature sensor is configured to determine, based on a bipolar transistor, a negatively correlated voltage and a negatively correlated current that are negatively correlated with temperature, and a positively correlated current that is positively correlated with temperature.
[0029] The coarse quantization adjustment module 1 is configured to output a current that is a multiple of the positively correlated current according to the initial coarse quantization control signal, and adjust the multiple relationship according to the intermediate coarse quantization control signal to finally obtain the coarse quantization current, so as to obtain the coarse quantization voltage based on the coarse quantization current.
[0030] The fine-tuning module 2 is configured to obtain the fine-tuning current based on the fine-tuning control signal and the positive correlation current.
[0031] Comparison module 3 is configured to convert the output current of the coarse quantization adjustment module into the output voltage of the coarse quantization adjustment module, and compare the output voltage of the coarse quantization adjustment module with the negative correlation voltage to obtain a comparison signal.
[0032] Control module 4 is configured to output a preset initial coarse quantization control signal and determine an intermediate coarse quantization control signal based on a comparison signal, so as to determine the coarse quantization value of temperature based on the coarse quantization voltage.
[0033] It is also configured to generate a fine quantization control signal based on the coarse quantization value of temperature; and to determine the fine quantization value of temperature based on the fine quantization current and charge conservation principle.
[0034] In this embodiment of the application, let Where X is a quantity that varies non-linearly with temperature, and V BE This can include negatively correlated voltage V that is negatively correlated with temperature. BE1 Or V BE2 ΔV BEThe positively correlated voltage is obtained by finding the value of X, which varies non-linearly with temperature.
[0035] The value of temperature gain μ can be obtained by quantizing the value of X using the following formula:
[0036]
[0037] Let X = n + μ′, where n is the coarse quantization part of X and μ′ is the fine quantization part of X.
[0038] In this embodiment, the output voltage of the coarse quantization adjustment module includes the initial voltage, the voltage after adjustment by a factor, and the coarse quantization voltage after the factor adjustment is completed.
[0039] Specifically, firstly, the control module outputs a preset initial coarse quantization control signal. The coarse quantization adjustment module then outputs an initial current that is a multiple of the positively correlated current based on this signal. The comparison module converts the output current of the coarse quantization adjustment module into its output voltage and compares this voltage with the negatively correlated voltage to obtain a comparison signal. The control module then determines an intermediate coarse quantization control signal based on this comparison signal. The intermediate coarse quantization control signal can be issued once or multiple times.
[0040] The coarse quantization adjustment module adjusts the multiplier relationship according to the intermediate coarse quantization control signal until the output voltage of the coarse quantization adjustment module approaches the negative correlation voltage, thereby obtaining the final coarse quantization current. The coarse quantization voltage is obtained based on the coarse quantization current, and the control module determines the coarse quantization value of the temperature based on the coarse quantization voltage.
[0041] When the control module determines the coarse temperature value, it indicates that the coarse temperature quantization process is complete, and the fine temperature quantization process begins. The control module generates a fine quantization control signal. The fine quantization adjustment module obtains the fine quantization current based on the fine quantization control signal and the positively correlated current. The control module then determines the fine temperature value based on the fine quantization current and the principle of charge conservation. The determination of the fine temperature value based on the fine quantization current and the principle of charge conservation can be achieved either by using the charge conservation equation Q = It, where Q is the charge, I is the current value during charging or discharging, and t is the charging time or discharging time within one cycle; or by obtaining the fine quantization voltage based on the fine quantization current and then determining the fine temperature value using Q = CV, where Q is the charge, C is the integrating capacitor, and V is the voltage value during charging or discharging.
[0042] Figure 2 The circuit diagram of the analog-to-digital conversion circuit of the temperature sensor provided in the embodiments of this application is as follows: Figure 2As shown, for example, the coarse quantization adjustment module 1 includes multiple coarse quantization current mirror units, each of which receives a positive correlation current and is electrically connected to the comparison module 3 and the control module 4 respectively.
[0043] Each coarse quantization current mirror unit is configured to be triggered and turned on by the control module, generating currents that are different multiples of the positively correlated current, so as to form the output current of the coarse quantization adjustment module.
[0044] In this embodiment, the number of coarse current mirror units can be selected according to actual needs. Since the temperature detection range of commonly used temperature sensors is generally -40℃ to 125℃, corresponding to a range of X of 7 to 24, a 5-bit (2...) sensor is selected. 5 =32) The coarse quantization current mirror unit can satisfy the variation range of X. In the coarse quantization process of the 5-bit coarse quantization current mirror unit, the current generated by the successive approximation register (SAR logic) is adjusted multiple times to generate a current with different multiples of the positively correlated current until the output voltage of the coarse quantization adjustment module is close to the negatively correlated voltage, thereby quickly determining the coarse quantization voltage.
[0045] For example, the currents generated by each coarse current mirror unit that are multiples of the positively correlated current include 1x positively correlated current, 2x positively correlated current, 4x positively correlated current, 8x positively correlated current, and 16x positively correlated current.
[0046] In this embodiment, the coarse quantization adjustment module includes five parallel branches (i.e., coarse quantization current mirror units). A reference positive correlation current generating device generates a reference positive correlation current. When the size of the coarse quantization current mirror unit is set to be one times the size of the reference positive correlation current generating device, the current generated by the coarse quantization current mirror unit is I. ΔVBE When the size of the coarse current mirror unit is set to twice the size of the reference positive correlation current generating device, the current generated by the coarse current mirror unit is When the size of the coarse current mirror unit is set to four times the size of the reference positive correlation current generating device, the current generated by the coarse current mirror unit is When the size of the coarse current mirror unit is set to 16 times the size of the reference positive correlation current generating device, the current generated by the coarse current mirror unit is During the coarse quantization process, the output current of the coarse quantization adjustment module is changed by turning on one or more coarse quantization current mirror units with different current values through the control module. This causes the output voltage of the coarse quantization adjustment module to gradually approach the negative correlation voltage. Then, based on the multiple relationship between the output voltage of the coarse quantization adjustment module and the positive correlation voltage, the final coarse quantization value of the temperature is obtained.
[0047] For example, the fine-tuning module 2 includes a fine-tuning current mirror unit, which receives a positively correlated current and is electrically connected to the comparison module and the control module.
[0048] The fine-quantization current mirror unit is configured to be triggered and turned on by the controlled module to generate a fine-quantization current that is a multiple of the positively correlated current, where m≤3.
[0049] In this embodiment, the fine-tuning module 2 includes a fine-tuning current mirror unit. A reference positive correlation current generating device generates a reference positive correlation current. When the size of the fine-tuning current mirror unit is set to 1 times the size of the reference positive correlation current generating device, the current generated by the fine-tuning current mirror unit is I. ΔVBE During the refinement process, the refinement current is determined by turning the refinement current mirror unit on or off through the control module, and then the refinement value of temperature is determined based on the refinement current and the principle of charge conservation.
[0050] like Figure 2 As shown, by way of example, both the coarse current mirror unit and the fine current mirror unit include a first PMOS transistor, a second PMOS transistor, and a third PMOS transistor.
[0051] The source of the first PMOS transistor is energized, the drain of the first PMOS transistor is electrically connected to the source of the second PMOS transistor, the drain of the second PMOS transistor is electrically connected to the source of the third PMOS transistor, the drain of the third PMOS transistor is electrically connected to the comparator module, the gates of the first PMOS transistor and the gates of the second PMOS transistor are both connected to a bias voltage with a positive correlation current, and the gate of the third PMOS transistor is electrically connected to the control module.
[0052] In the embodiments of this application, such as Figure 2 As shown, the first coarse current mirror unit can be composed of a first PMOS transistor P1, a second PMOS transistor P2, and a third PMOS transistor P3, generating a current I. ΔVBE The second coarse-quantization current mirror unit can be composed of the eleventh PMOS transistor P11, the twelfth PMOS transistor P12, and the thirteenth PMOS transistor P13, generating a current of The third coarse-quantization current mirror unit can be composed of the twenty-first PMOS transistor P21, the twenty-second PMOS transistor P22, and the twenty-third PMOS transistor P23, generating a current of... The fourth coarse current mirror unit can be composed of the thirty-first PMOS transistor P31, the thirty-second PMOS transistor P32, and the thirty-third PMOS transistor P33, generating a current of The fifth coarse current mirror unit can be composed of the forty-first PMOS transistor P41, the forty-second PMOS transistor P42, and the forty-third PMOS transistor P43, generating a current of Meanwhile, the fine-tuning current mirror unit can be composed of the 51st PMOS transistor P51, the 52nd PMOS transistor P52, and the 53rd PMOS transistor P53, generating a current of I. ΔVBE .
[0053] In this embodiment, the temperature-dependent current is the current generated by a current mirror composed of two transistors:
[0054]
[0055] Among them, V C V is the voltage at the emitter of the first transistor. A The adjusting resistor R is connected in series with the emitter of the second transistor. trim The voltage after that. By selecting appropriate dimensions, the current obtained by the coarse and fine current mirror units can be α times the temperature-dependent current. Therefore, the temperature-dependent current flowing through the coarse and fine current mirror units can be...
[0056] In this embodiment, each coarse quantization current mirror unit has a different size, and the current flowing through it is a different multiple of the current positively correlated with temperature. Depending on the actual temperature detection process, one or more coarse quantization current mirror units with different multiples can be turned on, thereby gradually approximating the output voltage of the coarse quantization adjustment module to a negatively correlated voltage, thus obtaining the final coarse quantization value of the temperature. In this embodiment, during the fine quantization process, the fine quantization current is determined by turning the fine quantization current mirror unit on or off, and then the fine quantization value of the temperature is determined by combining the principle of charge conservation.
[0057] like Figure 2 As shown, exemplarily, the comparison module 3 includes a first resistor R1 and a first comparator A1.
[0058] One end of the first resistor R1 is electrically connected to the positive input terminal of the coarse quantization adjustment module 1, the fine quantization adjustment module 2 and the first comparator A1, and the other end of the first resistor R1 is grounded; the negative input terminal of the first comparator A1 is connected to the negative correlation voltage, and the output terminal of the first comparator A1 is electrically connected to the control module 4.
[0059] The first resistor R1 is configured to convert the output current of the coarse quantization adjustment module 1 into the output voltage of the coarse quantization adjustment module 1.
[0060] The first comparator A1 is configured to output a continuous high-level signal when the output voltage of the coarse quantization adjustment module 1 is greater than the negative correlation voltage, and to output a continuous low-level signal when the output voltage of the coarse quantization adjustment module 1 is less than the negative correlation voltage.
[0061] In this embodiment, the output current of the coarse quantization adjustment module flows through the first resistor to obtain the output voltage of the coarse quantization adjustment module. Therefore, the voltage V connected to the positive input terminal of the first comparator is... inp for
[0062]
[0063] Among them, x·I ΔVBE This is the output voltage of the coarse quantization adjustment module. The voltage V connected to the negative input terminal of the first comparator is... inn The output voltage of the coarse quantization adjustment module is compared with the negative correlation voltage using a first comparator. When the output voltage of the coarse quantization adjustment module is greater than the negative correlation voltage, the first comparator outputs 1, i.e., a continuous high-level signal. Conversely, when the output voltage of the coarse quantization adjustment module is less than the negative correlation voltage, the first comparator outputs 0, i.e., a continuous low-level signal.
[0064] For example, combined Figure 2 and Figure 4 The control module 4 includes a coarse quantization control unit 41 and a fine quantization control unit 42.
[0065] The coarse quantization control unit 41 is configured to output a preset initial coarse quantization control signal, and to output an intermediate coarse quantization control signal that reduces the output voltage of the coarse quantization adjustment module based on a continuous high-level signal from the first comparator; and to output an intermediate coarse quantization control signal that increases the output voltage of the coarse quantization adjustment module based on a continuous low-level signal from the first comparator, so as to obtain a coarse quantization voltage and determine a coarse quantization value of temperature based on the coarse quantization voltage.
[0066] The fine quantization control unit 42 is configured to generate a fine quantization control signal based on a coarse quantization value of temperature, wherein the fine quantization signal includes a charging signal and a discharging signal; and to determine the fine quantization value of temperature based on the fact that the total charge obtained from the charging signal and the discharging signal are equal.
[0067] In this embodiment, the coarse quantization control unit first outputs a preset initial coarse quantization control signal, causing the coarse quantization adjustment module to output a current that is a multiple of the positively correlated current. A first comparator converts the output current of the coarse quantization adjustment module into an output voltage, which is then compared with a negatively correlated voltage. When the first comparator outputs a continuous high-level signal, the coarse quantization control unit outputs an intermediate coarse quantization control signal that decreases the output voltage of the coarse quantization adjustment module. When the first comparator outputs a continuous low-level signal, the coarse quantization control unit outputs an intermediate coarse quantization control signal that increases the output voltage of the coarse quantization adjustment module. The coarse quantization adjustment module adjusts the multiple relationship according to the intermediate coarse quantization control signal, thereby ultimately obtaining the coarse quantization current, coarse quantization voltage, and coarse quantization value.
[0068] When the coarse temperature quantization process ends, the fine quantization control unit generates a fine quantization control signal based on the coarse temperature quantization value, causing the fine quantization adjustment module to generate a first charge based on the charging signal and a second charge based on the discharging signal. Then, the fine temperature quantization value is determined based on the charge conservation principle of the first and second charges.
[0069] like Figure 2 As shown, exemplarily, the coarse quantization control unit 41 includes a successive approximation controller U1.
[0070] The input terminal of the successive approximation controller U1 is electrically connected to the output terminal of the first comparator A1. The control signal output terminal of the successive approximation controller U1 is electrically connected to the coarse quantization adjustment module 1 and selectively outputs control signals S0-S4. The quantization output terminal D of the successive approximation controller U1... out Output coarse quantization values.
[0071] In this embodiment, the successive approximation controller generates control signals S0-S4 based on the output of the first comparator, and selectively outputs control signals S0-S4 based on the comparison signal output by the first comparator, so as to control whether each coarse quantization current mirror unit in the coarse quantization adjustment module is selected or not, thereby adjusting the output current of the coarse quantization adjustment module.
[0072] Figure 3 A coarse-quantization flowchart of the analog-to-digital conversion circuit of the temperature sensor provided in the embodiments of this application is shown below. Figure 3 As shown, the coarse quantization process of the successive approximation controller specifically includes the following steps:
[0073] S1: The initial control signal of the successive approximation controller is S4S3S2S1S0=01111, indicating that only the fifth coarse quantization current mirror unit is selected at this time, so the output voltage V of the coarse quantization adjustment module is... inp =16ΔV BE Negative correlation voltage V inn =V BE1 After the voltage stabilizes, the voltage V applied to the positive input terminal is compared through the first comparator. inp and the negative input terminal connected to voltage V inn The size, i.e., comparing 16ΔV BE and V BE1 Size.
[0074] S21: When V inp =16ΔV BE >V inn At this time, the successive approximation controller adjusts the control signal to S4S3S2S1S0 = 10111, indicating that only the fourth coarse quantization current mirror unit is selected. Therefore, the output voltage V of the coarse quantization adjustment module is... inp =8ΔVEE Negative correlation voltage V inn =V BE1 After the voltage stabilizes, the voltage V applied to the positive input terminal is compared through the first comparator. inp and the negative input terminal connected to voltage V inn The size, i.e., comparing 8ΔV BE and V BE1 Size.
[0075] S211: When V inp =8ΔV BE >V inn At this time, the successive approximation controller adjusts the control signal to S4S3S2S1S0=11011, indicating that only the third coarse quantization current mirror unit is selected. Therefore, the output voltage V of the coarse quantization adjustment module is... inp =4ΔV BE Negative correlation voltage V inn =V BE1 After the voltage stabilizes, the voltage V applied to the positive input terminal is compared through the first comparator. inp and the negative input terminal connected to voltage V inn The size, i.e., comparing 4ΔV BE and V BE1 Size.
[0076] S2111: When V inp =4ΔV BE >V inn At this time, the successive approximation controller adjusts the control signal to S4S3S2S1S0=11101, indicating that only the second coarse quantization current mirror unit is selected. Therefore, the output voltage V of the coarse quantization adjustment module is... inp =2ΔV EE Negative correlation voltage V inn =V BE1 After the voltage stabilizes, the voltage V applied to the positive input terminal is compared through the first comparator. inp and the negative input terminal connected to voltage V inn The size, i.e., comparing 2ΔV BE and V BE1 Size.
[0077] S21111: When V inp =2ΔV BE >V inn At this time, the successive approximation controller adjusts the control signal to S4S3S2S1S0=11110, indicating that only the first coarse quantization current mirror unit is selected, and the output voltage V of the coarse quantization adjustment module is determined. inp =ΔV BE .
[0078] S21112: When V inp=2ΔV BE <V inn At this time, the successive approximation controller adjusts the control signal to S4S3S2S1S0 = 11100, indicating that the second coarse quantization current mirror unit and the first coarse quantization current mirror unit are selected, and the output voltage V of the coarse quantization adjustment module is determined. inp =2ΔV BE +ΔV BE =3ΔV BE .
[0079] S2112: When V inp =4ΔV BE <V inn At this time, the successive approximation controller adjusts the control signal to S4S3S2S1S0 = 11001, indicating that the third and second coarse quantization current mirror units are selected. Therefore, the output voltage V of the coarse quantization adjustment module... inp =4ΔV BE +2ΔV BE =6ΔV BE Negative correlation voltage V inn =V BE1 After the voltage stabilizes, the voltage V applied to the positive input terminal is compared through the first comparator. inp and the negative input terminal connected to voltage V inn The size, i.e., comparing 6ΔV BE and V BE1 Size.
[0080] S21121: When V inp =6ΔV BE >V inn At this time, the successive approximation controller adjusts the control signal to S4S3S2S1S0 = 11010, indicating that the third coarse quantization current mirror unit and the first coarse quantization current mirror unit are selected, and the output voltage V of the coarse quantization adjustment module is determined. inp =4ΔV BE +ΔV BE =5ΔV BE .
[0081] S21122: When V inp =6ΔV BE <V inn At this time, the successive approximation controller adjusts the control signal to S4S3S2S1S0 = 11000, indicating that the third coarse quantization current mirror unit, the second coarse quantization current mirror unit, and the first coarse quantization current mirror unit are selected, and the output voltage V of the coarse quantization adjustment module is determined. inp =4ΔV BE +2ΔV BE +ΔV BE =7ΔV BE .
[0082] S212: When V inp =8ΔV BE <V inn At this time, the successive approximation controller adjusts the control signal to S4S3S2S1S0 = 10011, indicating that the fourth coarse quantization current mirror unit and the third coarse quantization current mirror unit are selected. Therefore, the output voltage V of the coarse quantization adjustment module... inp =8ΔV BE +4ΔV BE =12ΔV BE Negative correlation voltage V inn =V BE1 After the voltage stabilizes, the voltage V applied to the positive input terminal is compared through the first comparator. inp and the negative input terminal connected to voltage V inn The size, i.e., comparing 12ΔV BE and V BE1 Size.
[0083] S2121: When V inp =12ΔV BE >V inn At this time, the successive approximation controller adjusts the control signal to S4S3S2S1S0 = 10101, indicating that the fourth coarse quantization current mirror unit and the second coarse quantization current mirror unit are selected. Therefore, the output voltage V of the coarse quantization adjustment module... inp =8ΔV BE +2ΔV BE =10ΔV BE Negative correlation voltage V inn =V BE1 After the voltage stabilizes, the voltage V applied to the positive input terminal is compared through the first comparator. inp and the negative input terminal connected to voltage V inn The size, i.e., comparing 10ΔV BE and V BE1 Size.
[0084] S21211: When V inp =10ΔV BE >V inn At this time, the successive approximation controller adjusts the control signal to S4S3S2S1S0 = 10110, indicating that the fourth coarse quantization current mirror unit and the first coarse quantization current mirror unit are selected, and the output voltage V of the coarse quantization adjustment module is determined. inp =8ΔV BE +ΔV BE =9ΔV BE .
[0085] S21212: When V inp =10ΔVBE <V inn At this time, the successive approximation controller adjusts the control signal to S4S3S2S1S0 = 10100, indicating that the fourth coarse quantization current mirror unit, the second coarse quantization current mirror unit, and the first coarse quantization current mirror unit are selected, and the output voltage Vinp of the coarse quantization adjustment module is determined to be 8ΔV. BE +2ΔV BE +ΔV BE =11ΔV BE .
[0086] S2122: When V inp =12ΔV BE <V inn At this time, the successive approximation controller adjusts the control signal to S4S3S2S1S0 = 10001, indicating that the fourth coarse quantization current mirror unit, the third coarse quantization current mirror unit, and the second coarse quantization current mirror unit are selected. Therefore, the output voltage Vinp of the coarse quantization adjustment module is 8ΔV. BE +4ΔV BE +2ΔV BE =14ΔV BE Negative correlation voltage V inn =V BE1 After the voltage stabilizes, the voltage V applied to the positive input terminal is compared through the first comparator. inp and the negative input terminal connected to voltage V inn The size, i.e., comparing 14ΔV BE and V BE1 Size.
[0087] S21221: When V inp =14ΔV BE >V inn At this time, the successive approximation controller adjusts the control signal to S4S3S2S1S0 = 10010, indicating that the fourth coarse quantization current mirror unit, the third coarse quantization current mirror unit, and the first coarse quantization current mirror unit are selected, and the output voltage V of the coarse quantization adjustment module is determined. inp =8ΔV BE +4ΔV BE +ΔV BE =13ΔV BE .
[0088] S21222: When V inp =14ΔV BE <V inn At this time, the successive approximation controller adjusts the control signal to S4S3S2S1S0 = 10000, indicating that the fourth, third, second, and first coarse quantization current mirror units are selected, and the output voltage V of the coarse quantization adjustment module is determined.inp =8ΔV BE +4ΔV BE +2ΔV BE +ΔV BE =15ΔV BE .
[0089] S22: When V inp =16ΔV BE <V inn At this time, the successive approximation controller adjusts the control signal to S4S3S2S1S0 = 00111, indicating that the fifth coarse quantization current mirror unit and the fourth coarse quantization current mirror unit are selected. Therefore, the output voltage V of the coarse quantization adjustment module... inp =16ΔV BE +8ΔV BE =24ΔV BE Negative correlation voltage V inn =V BE1 After the voltage stabilizes, the voltage V applied to the positive input terminal is compared through the first comparator. inp and the negative input terminal connected to voltage V inn The size, i.e., comparing 24ΔV BE and V BE1 Size.
[0090] S221: When V inp =24ΔV BE When the value is greater than Vinn, the successive approximation controller adjusts the control signal to S4S3S2S1S0 = 01011, indicating that the fifth coarse quantization current mirror unit and the third coarse quantization current mirror unit are selected at this time. Therefore, the output voltage V of the coarse quantization adjustment module is... inp =16ΔV BE +4ΔV BE =20ΔV BE Negative correlation voltage V inn =V BE1 After the voltage stabilizes, the voltage V applied to the positive input terminal is compared through the first comparator. inp and the negative input terminal connected to voltage V inn The size, i.e., comparing 20ΔV BE and V BE1 Size.
[0091] S2211: When V inp =20ΔV BE >V inn At this time, the successive approximation controller adjusts the control signal to S4S3S2S1S0=01101, indicating that the fifth coarse quantization current mirror unit and the second coarse quantization current mirror unit are selected. Therefore, the output voltage V of the coarse quantization adjustment module... inp =16ΔV BE +2ΔVBE =18ΔV BE Negative correlation voltage V inn =V BE1 After the voltage stabilizes, the voltage V applied to the positive input terminal is compared through the first comparator. inp and the negative input terminal connected to voltage V inn The size, i.e., comparing 18ΔV BE and V BE1 Size.
[0092] S22111: When V inp =18ΔV BE >V inn At this time, the successive approximation controller adjusts the control signal to S4S3S2S1S0=01110, indicating that the fifth coarse quantization current mirror unit and the first coarse quantization current mirror unit are selected, and the output voltage V of the coarse quantization adjustment module is determined. inp =16ΔV BE +ΔV BE =17ΔV BE .
[0093] S22112: When V inp =18ΔV BE <V inn At this time, the successive approximation controller adjusts the control signal to S4S3S2S1S0=01100, indicating that the fifth coarse quantization current mirror unit, the second coarse quantization current mirror unit, and the first coarse quantization current mirror unit are selected, and the output voltage V of the coarse quantization adjustment module is determined. inp =16ΔV BE +2ΔV BE +ΔV BE =19ΔV BE .
[0094] S2212: When V inp =20ΔV BE <V inn At this time, the successive approximation controller adjusts the control signal to S4S3S2S1S0 = 01001, indicating that the fifth coarse quantization current mirror unit, the third coarse quantization current mirror unit, and the second coarse quantization current mirror unit are selected. Therefore, the output voltage V of the coarse quantization adjustment module... inp =16ΔV BE +4ΔV BE +2ΔV BE =22ΔV BE Negative correlation voltage V inn =V BE1 After the voltage stabilizes, the voltage V applied to the positive input terminal is compared through the first comparator. inp and the negative input terminal connected to voltage V innThe size, i.e., comparing 22ΔV BE and V BE1 Size.
[0095] S22121: When V inp =22ΔV BE >V inn At this time, the successive approximation controller adjusts the control signal to S4S3S2S1S0 = 01010, indicating that the fifth coarse quantization current mirror unit, the third coarse quantization current mirror unit, and the first coarse quantization current mirror unit are selected, and the output voltage V of the coarse quantization adjustment module is determined. inp =16ΔV BE +4ΔV BE +ΔV BE =21ΔV BE .
[0096] S22122: When V inp =22ΔV BE <V inn At this time, the successive approximation controller adjusts the control signal to S4S3S2S1S0 = 01000, indicating that the fifth coarse quantization current mirror unit, the third coarse quantization current mirror unit, the second coarse quantization current mirror unit, and the first coarse quantization current mirror unit are selected, and the output voltage V of the coarse quantization adjustment module is determined. inp =16ΔV BE +4ΔV BE +2ΔV BE +ΔV BE =23ΔV BE .
[0097] S222: When V inp =24ΔV BE When <Vinn, the successive approximation controller adjusts the control signal to S4S3S2S1S0 = 00011, indicating that the fifth, fourth, and third coarse quantization current mirror units are selected at this time. Therefore, the output voltage V of the coarse quantization adjustment module is... inp =16ΔV BE +8ΔV BE +4ΔV BE =28ΔV BE Negative correlation voltage V inn =V BE1 After the voltage stabilizes, the voltage V applied to the positive input terminal is compared through the first comparator. inp and the negative input terminal connected to voltage V inn The size, i.e., comparing 28ΔV BE and V BE1 Size.
[0098] S2221: When V inp=28ΔV BE >V inn At this time, the successive approximation controller adjusts the control signal to S4S3S2S1S0 = 00101, indicating that the fifth coarse quantization current mirror unit, the fourth coarse quantization current mirror unit, and the second coarse quantization current mirror unit are selected. Therefore, the output voltage V of the coarse quantization adjustment module... inp =16ΔV BE +8ΔV BE +2ΔV BE =26ΔV BE Negative correlation voltage V inn =V BE1 After the voltage stabilizes, the voltage V applied to the positive input terminal is compared through the first comparator. inp and the negative input terminal connected to voltage V inn The size, i.e., comparing 26ΔV BE and V BE1 Size.
[0099] S22211: When V inp =26ΔV BE >V inn At this time, the successive approximation controller adjusts the control signal to S4S3S2S1S0 = 00110, indicating that the fifth coarse quantization current mirror unit, the fourth coarse quantization current mirror unit, and the first coarse quantization current mirror unit are selected, and the output voltage V of the coarse quantization adjustment module is determined. inp =16ΔV BE +8ΔV BE +ΔV BE =25ΔV BE .
[0100] S22212: When V inp =26ΔV BE <V inn At this time, the successive approximation controller adjusts the control signal to S4S3S2S1S0 = 00100, indicating that the fifth coarse quantization current mirror unit, the fourth coarse quantization current mirror unit, the second coarse quantization current mirror unit, and the first coarse quantization current mirror unit are selected, and the output voltage V of the coarse quantization adjustment module is determined. inp =16ΔV BE +8ΔV BE +2ΔV BE +ΔV BE =27ΔV BE .
[0101] S2222: When V inp =28ΔV BE <V innAt this time, the successive approximation controller adjusts the control signal to S4S3S2S1S0 = 00001, indicating that the fifth, fourth, third, and second coarse quantization current mirror units are selected. Therefore, the output voltage V of the coarse quantization adjustment module... inp =16ΔV BE +8ΔV BE +4ΔV BE +2ΔV BE =30ΔV BE Negative correlation voltage V inn =V BE1 After the voltage stabilizes, the voltage V applied to the positive input terminal is compared through the first comparator. inp and the negative input terminal connected to voltage V inn The size, i.e., comparing 30ΔV BE and V BE1 Size.
[0102] S22221: When V inp =30ΔV BE >V inn At this time, the successive approximation controller adjusts the control signal to S4S3S2S1S0 = 00010, indicating that the fifth, fourth, third, and first coarse quantization current mirror units are selected, and the output voltage V of the coarse quantization adjustment module is determined. inp =16ΔV BE +8ΔV BE +4ΔV BE +ΔV BE =29ΔV BE .
[0103] S22222: When V inp =30ΔV BE <V inn At this time, the successive approximation controller adjusts the control signal to S4S3S2S1S0 = 00000, indicating that the fifth, fourth, third, second, and first coarse quantization current mirror units are selected, and the output voltage V of the coarse quantization adjustment module is determined. inp =16ΔV BE +8ΔV BE +4ΔV BE +2ΔV BE +ΔV BE =31ΔV BE .
[0104] Based on the various scenarios described above, the output voltage of the coarse quantization adjustment module can be made to successively approach the negative correlation voltage V. BE1Thus, a coarse value of temperature can be determined based on the magnification factor.
[0105] Figure 4 This is a first circuit diagram of a fine-tuning control unit for the analog-to-digital conversion circuit of a temperature sensor provided in an embodiment of this application. (See diagram below.) Figure 4 As shown, exemplarily, the fine-tuning control unit 42 includes a negative correlation current source B1 and an integrating capacitor C. int The second comparator A2 and the flip-flop D1.
[0106] One end of the negative correlation current source B1 is connected to the coarse quantization adjustment module 1, the fine quantization adjustment module 2, and the integrating capacitor C, respectively. int One end of the first comparator is electrically connected to the positive input terminal of the second comparator A2, and the negative input terminal of the second comparator A2 is connected to the reference voltage V. REF1 The other end of the negatively correlated current source B1 and the integrating capacitor C int The other end of each is grounded. The output of the second comparator A2 is electrically connected to the data terminal of the flip-flop D1, and the output of the flip-flop D1 is electrically connected to the fine-tuning module 2.
[0107] Negative correlation current source B1 is configured to output a negative correlation current I that is negatively correlated with temperature. ctat .
[0108] Integrating capacitor C int It is configured to convert the current at the input of the second comparator A2 into an integrated voltage.
[0109] The second comparator A2 is configured to operate when the integrated voltage is greater than the reference voltage V. REF1 The system outputs a continuous high-level signal when the integrated voltage is less than the reference voltage V. REF1 It outputs a continuous low-level signal.
[0110] Trigger D1 is configured to convert a continuous high-level signal of the second comparator into a discrete high-level signal as a discharge signal to discharge the fine-quantization adjustment module 2, and to convert a continuous low-level signal of the second comparator into a discrete low-level signal as a charging signal to charge the fine-quantization adjustment module 2, so as to determine the fine-quantization value of the temperature based on the fact that the charging charge of the fine-quantization adjustment module 2 is equal to the discharging charge.
[0111] It should be noted that a first switch S1 is provided between the first resistor R1 and the coarse quantization adjustment module 1 and the fine quantization adjustment module 2, in conjunction with... Figure 2 , 4 As shown, the first switch S1 is closed during the coarse quantization process, causing the first resistor R1 to convert the output current of the coarse quantization adjustment module into the output voltage of the coarse quantization adjustment module. However, during the fine quantization process in this embodiment, the first switch S1 is in the off state because the charge conservation principle is achieved by using current.
[0112] In this embodiment of the application, the reference voltage V REF1 The voltage V, which is independent of temperature, in the traditional front-end detection circuit REF =V BE1 +α·ΔV BE The result is that V BE1 The negatively correlated voltage, ΔV, is negatively correlated with temperature. BE This is a positively correlated voltage with temperature. When the coarse quantization control unit completes the coarse quantization process, the coarse quantized value of temperature has been compressed to n·ΔV. BE ~(n+1)ΔV BE At this point, a finer quantization process can be performed, which can greatly shorten the analog-to-digital conversion time.
[0113] The control module generates fine-quantization control signals based on the coarse-quantization temperature value, specifically generating charging and discharging signals. When the trigger outputs a charging signal (i.e., bs = 0), the fine-quantization current mirror unit outputs current I. ΔVBE Because the coarse quantization adjustment module outputs n times I ΔVBE This results in a total charging current of (n+1)I. ptat -I ctat When the trigger outputs a discharge signal (i.e., bs = 1), the fine quantization current mirror unit does not output current because the coarse quantization adjustment module outputs n times I. ΔVBE The resulting discharge current is I. ctat -nI ptat According to the principle of charge conservation, we can obtain (1-η)((n+1)I) ptat -I ctat )=η(I ctat -nI ptat ), where η can be considered as the discharge time within one cycle, and 1- can be considered as the charging time within one cycle, then
[0114]
[0115] Therefore, the refined value of temperature μ′=1-η.
[0116] Therefore, the entire quantization process of temperature is completed, and the temperature X = n + μ can be obtained, where the coarse quantization value n is obtained by the coarse quantization control unit, and the fine quantization value μ′ is obtained by the fine quantization control unit.
[0117] Meanwhile, due to irrational factors such as comparator offset voltage, circuit noise, and current mirror mismatch, the coarse quantization value n may contain errors. Therefore, the input signal range for fine quantization can be appropriately increased from the original range ΔV. BE (n·ΔV BE ~(n+1)ΔVBE Increase to 3ΔV BE ((n-1)·ΔV BE ~(n+2)ΔV BE Thus, at this time The refined value of temperature is μ′=2-3η.
[0118] Figure 5 A second circuit diagram of a fine-tuning control unit for the analog-to-digital conversion circuit of a temperature sensor provided in an embodiment of this application. (See diagram below.) Figure 5 As shown, exemplarily, the fine-tuning control unit 42 includes a second resistor R2, an adder A3, an analog-to-digital converter U2, and an inverter D2.
[0119] One end of the second resistor R2 is electrically connected to the first input terminal of the coarse quantization adjustment module 1, the fine quantization adjustment module 2, and the adder A3, and the other end of the second resistor R2 is grounded; the second input terminal of the adder A3 is connected to a negative correlation voltage, the output terminal of the adder A3 is electrically connected to the input terminal of the analog-to-digital converter U2, the output terminal of the analog-to-digital converter U2 is electrically connected to the input terminal of the inverter D2, and the output terminal of the inverter D2 is electrically connected to the fine quantization adjustment module 42.
[0120] The second resistor R2 is configured to convert fine-quantized current into fine-quantized voltage.
[0121] Adder A3 is configured to add the fine-quantization voltage to the negative correlation voltage to obtain the evaluation voltage.
[0122] The analog-to-digital converter U2 is configured to obtain a discrete high-level signal or a discrete low-level signal based on the evaluation voltage of the adder A3.
[0123] Inverter D2 is configured to generate a charging signal based on discrete high-level signals from analog-to-digital converter U2 to charge fine-tuning module 42, and to generate a discharging signal based on discrete low-level signals from analog-to-digital converter U2 to discharge fine-tuning module 42, so as to determine the fine-tuning value of temperature based on the fact that the charging charge of fine-tuning module 42 is equal to the discharging charge.
[0124] It should be noted that the first resistor R1 can be reused as the second resistor R2, combined with Figure 2 , 5 As shown, the first switch S1 is closed during the coarse quantization process, so that the first resistor R1 converts the output current of the coarse quantization adjustment module into the output voltage of the coarse quantization adjustment module. During the fine quantization process in this embodiment, the first switch S1 is also closed to convert the fine quantization current into the fine quantization voltage.
[0125] When the inverter outputs a charging signal (i.e. When the fine-tuning module discharges according to the discharge signal, the resulting discharge charge is... When the inverter outputs a charging signal (i.e. When the fine-tuning module charges according to the charging signal, the resulting charging charge is Q1 = μ′(V BE -(n+1)ΔV BE )·C int According to the principle of charge conservation, Q0 + Q1 = 0, we can obtain Then the detailed value of temperature
[0126] The charge conservation principle in the fine-tuning module can be achieved either through current or voltage. When achieved through voltage, the coarse-tuning control unit completes the coarse-tuning process, and the coarse-tuned temperature value is compressed to n·ΔV. BE ~(n+1)ΔV BE The control module generates a fine quantization control signal based on the coarse quantization value of the temperature, reducing the charging and discharging time during the fine quantization process, improving quantization efficiency, and maintaining the conversion resolution and accuracy.
[0127] In this embodiment, the coarse quantization voltage is determined by repeatedly adjusting the coarse quantization control signal of the coarse quantization adjustment module, and the coarse quantization value of temperature is determined based on the coarse quantization voltage. The fine quantization current is determined by the fine quantization adjustment module, and the fine quantization value of temperature is determined based on the fine quantization current and the principle of charge conservation. The circuit is simple, occupies a small area, has low cost, maintains the conversion resolution and accuracy, and improves quantization efficiency.
[0128] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.
Claims
1. An analog-to-digital conversion circuit for a temperature sensor, characterized in that, It includes a coarse quantization adjustment module, a fine quantization adjustment module, a comparison module, and a control module; The temperature sensor is configured to determine, based on a bipolar transistor, a negatively correlated voltage and a negatively correlated current that are negatively correlated with temperature, and a positively correlated current that is positively correlated with temperature. The coarse quantization adjustment module is configured to output a current that is a multiple of the positively correlated current according to an initial coarse quantization control signal, and adjust the multiple relationship according to an intermediate coarse quantization control signal to finally obtain a coarse quantization current, so as to obtain a coarse quantization voltage based on the coarse quantization current. The fine-tuning module is configured to obtain a fine-tuning current based on the fine-tuning control signal and the positively correlated current; The comparison module is configured to convert the output current of the coarse quantization adjustment module into the output voltage of the coarse quantization adjustment module, and compare the output voltage of the coarse quantization adjustment module with the negative correlation voltage to obtain a comparison signal; The control module is configured to output a preset initial coarse quantization control signal and determine the intermediate coarse quantization control signal based on the comparison signal, so as to determine the coarse quantization value of the temperature based on the coarse quantization voltage. It is also configured to generate the fine quantization control signal based on the coarse quantization value of the temperature; And the refined value of the temperature is determined based on the refined current and charge conservation principle.
2. The analog-to-digital conversion circuit for the temperature sensor as described in claim 1, characterized in that, The coarse quantization adjustment module includes multiple coarse quantization current mirror units, each of which receives the positive correlation current and is electrically connected to the comparison module and the control module respectively. Each of the coarse quantization current mirror units is configured to be triggered and turned on by the control module to generate currents that have different multiples of the positively correlated current, so as to form the output current of the coarse quantization adjustment module.
3. The analog-to-digital conversion circuit for the temperature sensor as described in claim 2, characterized in that, The currents generated by each of the coarse current mirror units that are multiples of the positively correlated current include 1x positively correlated current, 2x positively correlated current, 4x positively correlated current, 8x positively correlated current, and 16x positively correlated current.
4. The analog-to-digital conversion circuit for the temperature sensor as described in claim 2, characterized in that, The fine-tuning module includes a fine-tuning current mirror unit, which receives the positive correlation current and is electrically connected to the control module. The refined current mirror unit is configured to be turned on by the control module to generate the refined current that is a multiple of the positively correlated current, where m≤3.
5. The analog-to-digital conversion circuit for the temperature sensor as described in claim 4, characterized in that, Both the coarse current mirror unit and the fine current mirror unit include a first PMOS transistor, a second PMOS transistor, and a third PMOS transistor. The source of the first PMOS transistor is energized, the drain of the first PMOS transistor is electrically connected to the source of the second PMOS transistor, the drain of the second PMOS transistor is electrically connected to the source of the third PMOS transistor, the drain of the third PMOS transistor is electrically connected to the comparator module, the gates of the first PMOS transistor and the second PMOS transistor are both connected to the bias voltage of the positive correlation current, and the gate of the third PMOS transistor is electrically connected to the control module.
6. The analog-to-digital conversion circuit for the temperature sensor as described in any one of claims 1-5, characterized in that, The comparison module includes a first resistor and a first comparator; One end of the first resistor is electrically connected to the coarse quantization adjustment module, the fine quantization adjustment module and the positive input terminal of the first comparator, and the other end of the first resistor is grounded; the negative input terminal of the first comparator is connected to the negative correlation voltage, and the output terminal of the first comparator is electrically connected to the control module. The first resistor is configured to convert the output current of the coarse quantization adjustment module into the output voltage of the coarse quantization adjustment module; The first comparator is configured to output a continuous high-level signal when the output voltage of the coarse quantization adjustment module is greater than the negative correlation voltage, and to output a continuous low-level signal when the output voltage of the coarse quantization adjustment module is less than the negative correlation voltage.
7. The analog-to-digital conversion circuit for the temperature sensor as described in claim 6, characterized in that, The control module includes a coarse quantization control unit and a fine quantization control unit; The coarse quantization control unit is configured to output a preset initial coarse quantization control signal, and to output an intermediate coarse quantization control signal that decreases the output voltage of the coarse quantization adjustment module based on a continuous high-level signal from the first comparator; and to output an intermediate coarse quantization control signal that increases the output voltage of the coarse quantization adjustment module based on a continuous low-level signal from the first comparator, so as to obtain the coarse quantization voltage, and to determine the coarse quantization value of the temperature based on the coarse quantization voltage. The fine quantization control unit is configured to generate the fine quantization control signal based on the coarse quantization value of the temperature, wherein the fine quantization control signal includes a charging signal and a discharging signal; and to determine the fine quantization value of the temperature based on the equality of the total charge obtained from the charging signal and the discharging signal, respectively.
8. The analog-to-digital conversion circuit for the temperature sensor as described in claim 7, characterized in that, The coarse quantization control unit includes a successive approximation controller; The input terminal of the successive approximation controller is electrically connected to the output terminal of the first comparator, the control signal output terminal of the successive approximation controller is electrically connected to the coarse quantization adjustment module, and the quantization output terminal of the successive approximation controller outputs the coarse quantization value.
9. The analog-to-digital conversion circuit for the temperature sensor as described in claim 7, characterized in that, The fine-grained control unit includes a negative correlation current source, an integrating capacitor, a second comparator, and a trigger; One end of the negative correlation current source is electrically connected to the coarse quantization adjustment module, the fine quantization adjustment module, one end of the integrating capacitor, and the positive input terminal of the second comparator. The negative input terminal of the second comparator is connected to a reference voltage. The other end of the negative correlation current source and the other end of the integrating capacitor are both grounded. The output terminal of the second comparator is electrically connected to the data terminal of the trigger. The output terminal of the trigger is electrically connected to the fine quantization adjustment module. The negative correlation current source is configured to output a negative correlation current that is negatively correlated with the temperature; The integrating capacitor is configured to convert the current at the input of the second comparator into an integrated voltage; The second comparator is configured to output a continuous high-level signal when the integrated voltage is greater than the reference voltage, and to output a continuous low-level signal when the integrated voltage is less than the reference voltage. The trigger is configured to convert a continuous high-level signal of the second comparator into a discrete high-level signal as the discharge signal to discharge the fine-tuning module, and to convert a continuous low-level signal of the second comparator into a discrete low-level signal as the charging signal to charge the fine-tuning module, so as to determine the fine-tuning value of the temperature based on the fact that the charging charge of the fine-tuning module is equal to the discharging charge.
10. The analog-to-digital conversion circuit for the temperature sensor as described in claim 7, characterized in that, The fine-tuning control unit includes a second resistor, an adder, an analog-to-digital converter, and an inverter; One end of the second resistor is electrically connected to the coarse quantization adjustment module, the fine quantization adjustment module, and the first input terminal of the adder, and the other end of the second resistor is grounded; the second input terminal of the adder is connected to the negative correlation voltage, the output terminal of the adder is electrically connected to the input terminal of the analog-to-digital converter, the output terminal of the analog-to-digital converter is electrically connected to the input terminal of the inverter, and the output terminal of the inverter is electrically connected to the fine quantization adjustment module; The second resistor is configured to convert the fine-quantized current into a fine-quantized voltage; The adder is configured to add the fine-quantization voltage to the negative correlation voltage to obtain the evaluation voltage; The analog-to-digital converter is configured to obtain a discrete high-level signal or a discrete low-level signal based on the evaluation voltage of the adder; The inverter is configured to generate the charging signal based on discrete high-level signals from the analog-to-digital converter to charge the fine-tuning module, and to generate the discharging signal based on discrete low-level signals from the analog-to-digital converter to discharge the fine-tuning module, for determining a fine-tuning value of the temperature based on the fact that the charging charge of the fine-tuning module equals the discharging charge.