CN114374390A - Temperature sensor circuit and chip - Google Patents

Abstract

The invention discloses a temperature sensor circuit and a chip, wherein the temperature sensor circuit comprises a coarse conversion ADC module, a bias current adjusting module, a fine conversion ADC module and an output module. The temperature signal detected by the temperature measuring device is subjected to analog-to-digital conversion by using the coarse conversion ADC module to obtain a first digital signal and an analog quantity residual signal, then the first digital signal is adjusted by the bias current adjusting module to output bias current to the fine conversion ADC module, the analog quantity residual signal is subjected to analog-to-digital conversion by the fine conversion ADC module according to the bias current to obtain a second digital signal, and finally the digital temperature signal is output by the output module according to the first digital signal and the second digital signal. Therefore, the temperature sensor circuit provided by the embodiment of the invention can ensure that the temperature sensor circuit can normally work in a temperature range, and meanwhile, the power consumption of the circuit is reduced, and the working performance of the circuit is improved.

Description

Temperature sensor circuit and chip

technical field

The invention relates to the technical field of integrated circuits, in particular to a temperature sensor circuit and a chip.

Background technique

At present, more and more chips need to monitor the temperature on the chip during operation. By monitoring the temperature, it can be determined whether a specific operation needs to be performed on the chip according to the collected ambient temperature or chip temperature data. For example, when it is detected that the ambient temperature is too high, the user is prompted to take protective actions on the chip, reduce the operating frequency of the chip or suspend the operation of the chip, thereby improving the functional safety level of the chip.

In order to quantify the results of the temperature sensor, it is necessary to use an analog to digital converter (ADC) to convert the temperature-sensitive physical quantity (voltage/current) on the chip into a digital quantity, and then obtain the temperature data on the chip. A more common choice is to quantify the base-emitter voltage of the transistor (V _BE ) and the difference ΔV _BE between the base-emitter voltage of the transistor operating at different current densities. In order to obtain higher temperature measurement accuracy, the ADC circuit used by the temperature sensor generally requires high resolution. The traditional technical solution is to use an oversampling sigma-delta ADC to trade time for accuracy. sigma-deltaADC utilizes oversampling technology and noise shaping technology to obtain high resolution and precision, but while obtaining high precision, the conversion time consumed will be correspondingly longer.

The sigma-delta ADC is a switched capacitor circuit. During the operation of the circuit, the amplifier will continuously charge and discharge the capacitor, and the comparator circuit in the sigma-delta ADC also needs to constantly judge the voltage of the comparator. , and zoomed to a digital level. Therefore, both the operational amplifier and the comparator in the sigma-delta ADC need to have sufficient power consumption to ensure sufficient bandwidth. Since the bandwidth changes with temperature, the speed of the amplifier changes at high and low temperature.

In related designs, generally the higher the temperature, the slower the amplifier will be. To meet the accuracy at high temperature, the amplifier needs to be designed to have a higher speed at high temperature than the lowest target speed of the amplifier. But this results in a large excess of amplifier speed at low temperatures, where the temperature sensor consumes significantly more power than is actually required.

SUMMARY OF THE INVENTION

The present invention aims to solve one of the technical problems in the related art at least to a certain extent. Therefore, an object of the present invention is to provide a temperature sensor circuit, which can ensure that the temperature sensor circuit can work normally within the temperature range, while reducing the power consumption of the circuit and improving the working performance of the circuit.

The second object of the present invention is to provide a chip.

In order to achieve the above purpose, the embodiment of the first aspect of the present invention provides a temperature sensor circuit, which includes a rough conversion ADC module, which is used to perform analog-to-digital conversion on an input analog temperature signal to obtain a first digital signal and an analog residual. difference signal; a bias current adjustment module for outputting a bias current according to the first digital signal; a fine conversion ADC module for performing analog-to-digital conversion on the analog residual signal according to the bias current to obtain a second digital signal; an output module for outputting a digital temperature signal according to the first digital signal and the second digital signal.

The temperature sensor circuit of the embodiment of the present invention includes a coarse conversion ADC module, a bias current adjustment module, a fine conversion ADC module and an output module. Wherein, first use the rough conversion ADC module to perform analog-to-digital conversion on the temperature signal detected by the temperature measurement device to obtain the first digital signal and the analog residual signal, and then the bias current adjustment module adjusts the first digital signal to Output the bias current to the fine conversion ADC module, the fine conversion ADC module performs analog-to-digital conversion on the analog residual signal according to the bias current to obtain the second digital signal, and finally uses the output module according to the first digital signal and the second digital signal. Output digital temperature signal. Therefore, the temperature sensor circuit of the embodiment of the present invention can ensure that the temperature sensor circuit can work normally within the temperature range, while reducing the power consumption of the circuit and improving the working performance of the circuit.

In some embodiments of the present invention, the bias current adjustment module includes: a current adjustment signal generation unit for generating a current adjustment signal according to the first digital signal; and a bias current generation unit for generating a current adjustment signal according to the current A conditioning signal produces the bias current.

In some embodiments of the present invention, the current adjustment signal generating unit obtains a switch control signal corresponding to the bias current by using a look-up table, so as to control the bias current generating unit to generate the bias current.

In some embodiments of the present invention, the bias current generating unit includes: a current source; a first transistor, the drain of the first transistor is connected to the gate and then connected to the current source; N second transistors , the drains of each of the second transistors are connected together as an output terminal of the bias current generating unit, and the gate of each of the second transistors is connected to the drain of the first transistor through a first switch and connected to the source of the first transistor through a second switch, the sources of each of the second transistors are connected together and then connected to the source of the first transistor and connected to ground, wherein , where N is a positive integer.

In some embodiments of the present invention, both the first transistor and the second transistor are MOS transistors.

In some embodiments of the present invention, the switch control signal corresponding to the first switch is opposite to the switch control signal corresponding to the second switch.

In some embodiments of the present invention, the output module includes a register for shifting the first digital signal to the left to the same number of bits as the resolution of the fine-conversion ADC module, and then converting the first digital signal to the same number as the second digital signal. Superposition is performed to obtain the digital temperature signal.

In some embodiments of the present invention, the coarse conversion ADC module is one of a successive approximation analog-to-digital converter, a pipeline converter, and a flash converter.

In some embodiments of the present invention, the fine-conversion ADC module is a sigma-delta analog-to-digital converter.

In some embodiments of the present invention, the analog temperature signal is obtained by a temperature measuring device, wherein the temperature measuring device is a triode or a temperature sensing resistor.

In order to achieve the above object, an embodiment of the second aspect of the present invention provides a chip including the temperature sensor circuit according to the above embodiment.

The chip of the embodiment of the present invention can ensure that the temperature sensor circuit can work normally within the temperature range through the sensor circuit in the above-mentioned embodiment, while reducing the power consumption of the circuit and improving the working performance of the circuit.

Additional aspects and advantages of the present invention will be set forth, in part, from the following description, and in part will be apparent from the following description, or may be learned by practice of the invention.

Description of drawings

1 is a structural block diagram of a temperature sensor circuit according to an embodiment of the present invention;

2 is a schematic diagram of coarse conversion and fine conversion according to a specific embodiment of the present invention;

3 is a schematic diagram of signal and conversion mode switching according to a specific embodiment of the present invention;

4 is a structural block diagram of a temperature sensor circuit according to a specific embodiment of the present invention;

5 is a schematic diagram of a bias current adjustment module according to an embodiment of the present invention;

6 is a schematic diagram of the relationship between the transconductance of the input pair of tubes and the temperature according to a specific embodiment of the present invention;

FIG. 7 is a block diagram of a chip structure according to an embodiment of the present invention.

Detailed ways

The following describes in detail the embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals refer to the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary, and are intended to explain the present invention and should not be construed as limiting the present invention.

The temperature sensor circuit and chip according to the embodiments of the present invention are described below with reference to the accompanying drawings.

FIG. 1 is a structural block diagram of a temperature sensor circuit according to an embodiment of the present invention.

As shown in FIG. 1 , the present invention proposes a two-step temperature sensor circuit 10 , the two-step temperature sensor circuit 10 includes a coarse conversion ADC module 11 , a bias current adjustment module 12 , a fine conversion ADC module 13 and an output module 14.

The rough conversion ADC module 11 is used to perform analog-to-digital conversion on the input analog temperature signal to obtain the first digital signal and the analog residual signal; the bias current adjustment module 12 is used to output the bias current according to the first digital signal; The fine conversion ADC module 13 is used for performing analog-to-digital conversion on the analog residual signal according to the bias current to obtain the second digital signal; the output module 14 is used for outputting the digital temperature signal according to the first digital signal and the second digital signal.

First of all, it should be noted that the two-step temperature sensor includes a temperature measuring device and a two-step temperature sensor circuit 10. This embodiment mainly defines the two-step temperature sensor circuit 10. The two-step temperature sensor circuit 10 can measure the temperature. The temperature signal detected by the temperature device is converted into two steps, so the output end of the temperature measurement device can be connected to the input end of the two-step temperature sensor circuit 10. Specifically, the output end of the temperature measurement device is connected to the rough conversion ADC module. 11's input connection. It can be understood that the temperature measuring device may be a device capable of generating a voltage related to temperature, such as a triode or a temperature sensing resistor.

Specifically, the temperature measuring device can detect the temperature and output an analog quantity related to the detected temperature, such as a current signal or a voltage signal, etc. The two-step temperature sensor circuit 10 can convert the analog quantity into a digital quantity and output it. More specifically, the rough conversion ADC module 11 first performs conversion processing on the analog temperature signal, and obtains the first digital signal and a part of the analog residual signal, and the bias current adjustment module 12 takes the first digital signal as the input signal, and The bias current is output according to the input signal, and the fine conversion ADC module 13 takes the analog residual signal as the input signal, and performs analog-to-digital conversion on the analog residual signal according to the bias adjustment current to obtain the second digital signal , the output module of this embodiment takes the first digital signal and the second digital signal as input signals respectively, and calculates and obtains a digital temperature signal according to the first digital signal and the second digital signal, and uses the digital temperature signal as the two-step The output signal of the temperature sensor circuit 10 is output.

It should be noted that, when the fine conversion ADC module 13 of this embodiment performs the analog-to-digital conversion processing on the analog residual signal, it first adjusts the bias current output by the bias current adjustment module 12, so that the The temperature sensor's power consumption and utilization are optimized over the entire temperature range.

In this embodiment, the rough conversion ADC module 11 may be a successive approximation analog-to-digital converter, a pipeline converter or a flash converter. It can be understood that although the precision of the rough conversion ADC module 11 is not high, its conversion speed is very high. Fast, can quickly perform a rough conversion of the analog temperature signal. The fine conversion ADC module 13 in this embodiment is a sigma-delta analog-to-digital converter. It can be understood that, after the fine conversion is performed by the fine conversion ADC module 13, very precise temperature measurement accuracy can be achieved.

More specifically, it is assumed that the analog temperature signal X generated by the temperature measuring device decreases as the temperature increases. As shown in Figure 2, from -40°C to 125°C, the analog temperature signal X changes from 20 to 5. The role of the rough conversion ADC module 11 can locate the analog temperature signal X between n and n+1, but at this time, the width of each grid is still very large, optionally, the temperature corresponding to each grid can be 5 ℃～10℃, the temperature corresponding to each grid in this embodiment is about 10℃. After the position interval where the analog temperature signal is located is determined by the coarse conversion ADC module 11 , the fine conversion ADC module 13 can be used to perform finer conversion on this basis. In this embodiment, the fine conversion ADC module 13 can divide the grid n~n+1 determined by the coarse conversion ADC module 11 into ²⁹ grids, and determine the value of the analog temperature signal X in a small In the grid, the temperature of a small grid at this time is about 0.01°C to 0.02°C, which can achieve very precise temperature measurement accuracy.

It should be noted that the embodiment of the present invention does not limit the temperature size represented by each grid divided by the coarse conversion ADC module 11 and the fine conversion ADC module 13 , and may be divided according to actual requirements.

In one embodiment of the present invention, as shown in FIG. 3 , what are represented in the figure are the enable signal EN, the clock signal CLK, the comparator signal CLK_COMP, the comparator output period and the conversion model, respectively. After the two-step temperature sensor circuit starts to work, the rough conversion ADC module completes the rough conversion of the analog temperature signal after 5 clock cycles; the conversion result at this time represents a relatively rough temperature, but its accuracy is enough to help adjust The power consumption of this sensor circuit. After the rough conversion, the current adjustment can be performed, and then the fine conversion can be performed. It should be noted that the specific number of clock cycles is related to the type of the rough conversion ADC module and the size of the temperature represented by each scale, and is not limited by this embodiment.

In some embodiments of the present invention, the bias current adjustment module includes a current adjustment signal generation unit and a bias current generation unit, wherein the current adjustment signal generation unit is configured to generate a current adjustment signal according to the first digital signal, and the bias current generates The unit is used to generate the bias current according to the current regulation signal.

Specifically, the bias current adjustment module in this embodiment may include a current adjustment signal generation unit and a bias current generation unit, wherein the current adjustment signal generation unit may be configured to receive the first digital signal sent by the rough conversion ADC module, and then A corresponding current adjustment signal is generated according to the first digital signal, and the current adjustment signal is sent to the bias current generation unit, and the bias current generation unit can generate a bias current according to the signal after receiving the current adjustment signal, The bias current is then sent to the fine conversion ADC module, so that the fine conversion ADC module can process the analog residual signal according to the bias current to output a second digital signal.

In some embodiments of the present invention, as shown in FIG. 4 , the current adjustment signal generation unit may obtain the switch control signal corresponding to the bias adjustment power supply by using the look-up table 121 to control the bias current generation unit 122 to generate the bias current .

Specifically, the rough conversion ADC module 11 in this embodiment may be a SAR ADC (successive approximation register ADC, successive approximation analog-to-digital converter) module, the fine conversion ADC module 13 may be a sigma-delta ADC, and the output module 14 includes a register, offset The bias current adjustment module 12 may include a lookup table 121 and a bias current generation unit 122 .

More specifically, after the analog temperature signal output by the temperature measuring device is input to the SAR ADC 11, the SAR ADC 11 processes the analog temperature signal to generate a first digital signal and an analog residual signal, and the first digital signal can be sent to the look-up table. 121 , so that the lookup table 121 can obtain the switch control signal corresponding to the bias adjustment power supply, and then use the switch control signal to control the bias current generating unit 122 to generate the bias current.

It should be noted that in this embodiment, a look-up table can be preset and then stored in the non-volatile storage device of the chip. The look-up table contains the correspondence between the current temperature value and the optimal bias current of the Σ-Δ ADC of the fine converter relationship, the bias current generating unit can generate different bias currents according to the look-up table.

In this embodiment, as shown in FIG. 5 , the bias current generating unit includes a current source, a first transistor and N second transistors.

Wherein, the drain of the first transistor is connected to the gate and then connected to the current source; the drains of each second transistor are connected together to serve as the output end of the bias current generating unit, and the gate of each second transistor passes through the A switch is connected to the drain of the first transistor and is connected to the source of the first transistor through a second switch, the sources of each second transistor are connected together and then connected to the source of the first transistor and to ground connection, where N is a positive integer.

Specifically, referring to FIG. 1 , FIG. 4 and FIG. 5 , the lookup table 121 changes the switching states of s0 to sn and s0_n to s1_n according to the result of the rough conversion ADC module 11 and the preset corresponding relationship between temperature and current control, and s0 to sn corresponds to the first switch of the bias current generating unit 122 , and s0_n˜s1_n correspond to the second switch of the bias current generating unit 122 . The switch control signal corresponding to the first switch is opposite to the switch control signal corresponding to the second switch, that is, s0_n is the inverted signal of s0, s1_n is the inverted signal of s1, and so on. In the circuit of the bias current generating unit 122, the first transistor and the second transistor are both NMOS transistors. If s0 is 0, the NMOS transistor in the branch is in an off state, and the current in the branch is in an off state. It will not be added to the total current, so that the current provided to the fine converter is reduced; and if it is 1, the NMOS tube in this branch is in an on state, and forms a current mirror with the leftmost NMOS tube, the branch The current is a proportional copy of the leftmost current source, and the current will be added to the total bias current to provide the fine conversion ADC module to adjust the current of the fine conversion ADC module.

It should be noted that, the first transistor and the second transistor in this embodiment may also be PMOS transistors, and the specific working mode can be adjusted by referring to the working mode of the NMOS transistor, which will not be repeated here.

Referring to FIG. 4 , the output module includes a register. The register shifts the first digital signal to the left to the same number of bits as the resolution of the fine conversion ADC module, and superimposes it with the second digital signal to obtain a digital temperature signal.

Specifically, after the fine conversion ADC module completes the processing of the analog residual signal according to the bias current, a second digital signal can be generated and sent to the register 14, and the register 14 can combine the second digital signal with the coarse conversion ADC module. 11. Perform superposition processing on the first digital signal obtained by processing to obtain a digital temperature signal. More specifically, the register 14 can first shift the first digital signal to the left to obtain the specific temperature value corresponding to the lower limit of the interval where the analog temperature signal is located, and then add the lower limit temperature value of the interval to the corresponding temperature value of the second digital signal. temperature value, and then a digital temperature signal can be obtained, and the digital temperature signal is output.

带宽GBW和g_m成正比，其中C为放大器输出端的负载电容，因此低温时g_m的增大会使得放大器实际速度超过精度指标所需要的速度，造成功耗的浪费。本发明中偏置电流调整模块根据粗转换ADC模块的输出结果对∑-ΔADC的偏置电流进行调整，又根据公式

可知，在低温时实时降低偏置的大小，可以使温度传感器在整个工作温度范围内，g_m维持在稳定的大小，其中，μ_n/p是运算放大器中NMOS或PMOS输入对管的迁移率，I是输入对管的电流。在本实施例中，常温时偏置电流可以减小约(1.2²-1)/1.2²≈30％，-40℃时偏置电流可以减小约(1.44²-1)/1.44²≈51％。在整个转换的过程中，细转换ADC模块的工作时间占比很高，本实施例中细转换ADC模块∑-ΔADC的工作时间占两步式温度传感器电路总工作时间的95％以上。从而相比于相关技术方案，本实施例使温度传感器整体功耗在常温时减小约为95％×30％＝28.5％，在-40℃功耗减小约95％×51％＝48％。It should be noted that when the bias current adjustment module is not used, that is, when the bias current is a fixed value, the simulation results of the relationship between the transconductance g _m of the amplifier input to the tube and the temperature change are shown in Figure 6, at room temperature (25°C) The _gm in the environment is 1.2 times that at 120°C, and the _gm in the low temperature (-40°C) environment is 1.44 times that at 120°C. The accuracy index of the temperature sensor is determined by the minimum bandwidth of the internal operational amplifier (similar to the comparator), which is calculated by the bandwidth GBW of the amplifier:

The bandwidth GBW is proportional to g _m , where C is the load capacitance of the amplifier output, so the increase of g _m at low temperature will make the actual speed of the amplifier exceed the speed required by the accuracy index, resulting in waste of power consumption. In the present invention, the bias current adjustment module adjusts the bias current of the Σ-Δ ADC according to the output result of the rough conversion ADC module, and according to the formula

It can be known that reducing the size of the bias in real time at low temperature can keep the temperature sensor g _m in a stable size in the entire operating temperature range, where μ _n/p is the mobility of the NMOS or PMOS input to the tube in the operational amplifier , I is the current input to the tube. In this embodiment, the bias current can be reduced by about (1.2 ² -1)/1.2 ² ≈30% at room temperature, and the bias current can be reduced by about (1.44 ² -1)/1.44 ² ≈51 at -40°C %. During the whole conversion process, the working time of the fine-conversion ADC module accounts for a high proportion. In this embodiment, the working time of the fine-conversion ADC module Σ-ΔADC accounts for more than 95% of the total working time of the two-step temperature sensor circuit. Therefore, compared with the related technical solution, this embodiment reduces the overall power consumption of the temperature sensor by about 95%×30%=28.5% at normal temperature, and about 95%×51%=48% at -40°C. .

It should be noted that, in the fine conversion stage of the two-step temperature sensor circuit of the embodiment of the present invention, the bias current adjustment module adjusts the bias current provided to the fine conversion ADC module according to the temperature conversion result of the coarse conversion ADC module to offset the semiconductor The effect of the device changes with temperature, so that the temperature sensor has a better amplifier speed in the whole temperature range, which can greatly reduce the power consumption in the low temperature region compared with the related technology.

To sum up, the two-step temperature sensor circuit of the embodiment of the present invention can ensure that the temperature sensor circuit can work normally within the temperature range, while reducing the power consumption of the circuit and improving the working performance of the circuit.

FIG. 7 is a block diagram of a chip structure according to an embodiment of the present invention.

Further, as shown in FIG. 7 , the present invention provides a chip 100 , and the chip 100 includes the two-step temperature sensor circuit 10 in the above embodiment.

Through the two-step temperature sensor circuit in the above embodiments, the chip of the embodiment of the present invention can ensure that the temperature sensor circuit can work normally within the temperature range, reduce the power consumption of the chip, and improve the working performance of the chip.

In the description of this specification, description with reference to the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples", etc., mean specific features described in connection with the embodiment or example , structure, material or feature is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", " Rear, Left, Right, Vertical, Horizontal, Top, Bottom, Inner, Outer, Clockwise, Counterclockwise, Axial, The orientations or positional relationships indicated by "radial direction", "circumferential direction", etc. are based on the orientations or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying the indicated devices or elements. It must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be construed as a limitation of the present invention.

In addition, terms such as "first" and "second" used in the embodiments of the present invention are only used for the purpose of description, and should not be understood as indicating or implying relative importance, or implicitly indicating the instructions in this embodiment. number of technical features. Therefore, the features defined by terms such as "first" and "second" in the embodiments of the present invention may expressly or implicitly indicate that at least one of the features is included in the embodiment. In the description of the present invention, the word "plurality" means at least two or more than two, such as two, three, four, etc., unless otherwise explicitly and specifically defined in the embodiments.

In the present invention, unless otherwise expressly specified or limited in the embodiments, the terms "installed", "connected", "connected" and "fixed" in the embodiments should be understood in a broad sense. For example, the connection can be It can be a fixed connection, a detachable connection, or an integrated connection. It can be understood that it can also be a mechanical connection, an electrical connection, etc.; of course, it can also be directly connected, or indirectly connected through an intermediate medium, or two The communication within an element, or the interaction between two elements. Those of ordinary skill in the art can understand the specific meanings of the above terms in the present invention according to the specific implementation.

In the present invention, unless otherwise expressly specified and limited, a first feature "on" or "under" a second feature may be in direct contact between the first and second features, or the first and second features indirectly through an intermediary touch. Also, the first feature being "above", "over" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is level higher than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature has a lower level than the second feature.

Although the embodiments of the present invention have been shown and described above, it should be understood that the above-mentioned embodiments are exemplary and should not be construed as limiting the present invention. Embodiments are subject to variations, modifications, substitutions and variations.

Claims (11)

1. a temperature sensor circuit, is characterized in that, comprises: The rough conversion ADC module is used to perform analog-to-digital conversion on the input analog temperature signal to obtain the first digital signal and the analog residual signal; a bias current adjustment module, configured to output a bias current according to the first digital signal; a fine conversion ADC module, configured to perform analog-to-digital conversion on the analog residual signal according to the bias current to obtain a second digital signal; The output module is used for outputting a digital temperature signal according to the first digital signal and the second digital signal. 2. The temperature sensor circuit according to claim 1, wherein the bias current adjustment module comprises: a current adjustment signal generating unit, configured to generate a current adjustment signal according to the first digital signal; A bias current generating unit, configured to generate the bias current according to the current adjustment signal. 3 . The temperature sensor circuit according to claim 2 , wherein the current adjustment signal generating unit obtains the switch control signal corresponding to the bias current by means of a look-up table, so as to control the generation of the bias current. 4 . A cell generates the bias current. 4. The temperature sensor circuit according to claim 3, wherein the bias current generating unit comprises: current source; a first transistor, the drain of the first transistor is connected to the gate and then connected to the current source; N second transistors, the drains of each of the second transistors are connected together as an output terminal of the bias current generating unit, and the gate of each of the second transistors is connected to the The drain of the first transistor is connected to the source of the first transistor through a second switch, the sources of each of the second transistors are connected together and then connected to the source of the first transistor, and Connect to ground, where N is a positive integer. 5 . The temperature sensor circuit according to claim 4 , wherein the first transistor and the second transistor are both MOS transistors. 6 . 6 . The temperature sensor circuit of claim 4 , wherein the switch control signal corresponding to the first switch is opposite to the switch control signal corresponding to the second switch. 7 . 7. The temperature sensor circuit according to any one of claims 1-6, wherein the output module comprises a register for shifting the first digital signal to the left to distinguish it from the fine conversion ADC module After the number of bits with the same rate, it is superimposed with the second digital signal to obtain the digital temperature signal. 8. The temperature sensor circuit according to any one of claims 1-6, wherein the rough conversion ADC module is one of a successive approximation analog-to-digital converter, a pipeline converter and a flash converter kind. 9 . The temperature sensor circuit according to claim 1 , wherein the fine conversion ADC module is a sigma-delta analog-to-digital converter. 10 . 10 . The temperature sensor circuit according to claim 1 , wherein the analog temperature signal is obtained by a temperature measuring device, wherein the temperature measuring device is a triode or a temperature sensing resistor. 11 . 11. A chip, characterized by comprising the temperature sensor circuit according to any one of claims 1-10.

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