CMOS temperature sensing front-end circuit with adjustable output voltage range

Abstract

The utility model belongs to the field of temperature sensors, and particularly discloses a CMOS temperature-sensing front-end circuit with an adjustable output voltage range, which comprises a temperature-sensing module, a bias module, an output module and a power supply module, the power supply module is respectively connected with the temperature-sensing module, the bias module and the output module, the temperature-sensing module is respectively connected with the bias module and the output module, and the bias module is connected with the output module. The bias module is connected with the output module; the power module provides voltage for the temperature sensing module, the bias module and the output module, the temperature sensing module detects temperature and outputs current with a positive temperature coefficient and reference voltage irrelevant to the temperature, and the bias module converts the reference voltage into bias current needed by the output module. And the output module converts the current with the positive temperature coefficient into a controllable voltage with a negative temperature coefficient. According to the utility model, the flexible control of the output voltage range is realized, and the precision of the temperature sensor is improved. The utility model is suitable for the temperature sensor system.

Description

Technical Field

[0001] The utility model belongs to the field of temperature sensors, in particular to a CMOS temperature sensing front-end circuit with an adjustable output voltage range. Background Art

[0002] With the continuous development of the semiconductor industry, chip integration continues to increase, leading to increased power consumption. Excessive chip heat generation has become a major factor limiting their performance. To monitor internal chip temperature and improve chip reliability, on-chip integrated temperature sensors are currently widely used. Integrated temperature sensors not only have high integration and a small footprint, but also offer high accuracy, low power consumption, low cost, and direct digital output.

[0003] The temperature sensing front end is a crucial component of a temperature sensor. It is the module within the entire temperature sensor system that converts temperature information into a voltage or time-domain signal. Its performance directly impacts the performance of the temperature sensor system. Representing temperature information using a voltage signal offers higher accuracy and resolution, making it more widely used. However, this method has a limited output range, hindering system accuracy. Improving the output range of the voltage-domain temperature sensing front end, and thereby improving system accuracy, is a pressing issue. Utility Model Content

[0004] The purpose of the utility model is to provide a CMOS temperature sensing front-end circuit with an adjustable output voltage range, so as to achieve flexible control of the output voltage range and improve the accuracy of the temperature sensor.

[0005] In order to achieve the above-mentioned purpose, the technical methods adopted by the present invention are as follows:

[0006] A CMOS temperature-sensing front-end circuit with an adjustable output voltage range includes a temperature-sensing module, a bias module, an output module, and a power module. The power module is connected to the temperature-sensing module, the bias module, and the output module, respectively. The temperature-sensing module is connected to the bias module and the output module, respectively. The bias module is connected to the output module. The power module provides voltage to the temperature-sensing module, the bias module, and the output module. The temperature-sensing module detects temperature and outputs a current with a positive temperature coefficient and a reference voltage that is independent of temperature. The bias module converts the reference voltage into a bias current required by the output module. The output module converts the current with a positive temperature coefficient into a controllable voltage with a negative temperature coefficient.

[0007] As a limitation: the temperature sensing module includes a first diode, N second diodes, a third diode, a first resistor, a second resistor, a first MOS tube, a second MOS tube, a third MOS tube, a fourth MOS tube, a fifth MOS tube, a sixth MOS tube, M seventh MOS tubes, M eighth MOS tubes, a ninth MOS tube and a tenth MOS tube; the sources of the first MOS tube, the third MOS tube, the fifth MOS tube and the M seventh MOS tubes are all connected to the power module, the first MOS tube, the third MOS tube, the fifth MOS tube and the M seventh MOS tubes share a gate, the drain of the first MOS tube is connected to the source of the second MOS tube, the drain of the third MOS tube is respectively connected to the gate of the third MOS tube and the source of the fourth MOS tube, the drain of the fifth MOS tube is connected to the source of the sixth MOS tube, the drain of each seventh MOS tube is connected to the source of the eighth MOS tube, and the M seventh MOS tubes are connected one by one to the M eighth MOS tubes. The second MOS transistor, the fourth MOS transistor, the sixth MOS transistor, and the M eighth MOS transistors share a common gate; the drain of the second MOS transistor is respectively connected to the drain of the ninth MOS transistor and the gate of the ninth MOS transistor; the drain of the fourth MOS transistor is respectively connected to the gate of the fourth MOS transistor and the drain of the tenth MOS transistor; the drain of the sixth MOS transistor is connected to one end of the second resistor; the drains of the M eighth MOS transistors are connected to output a current with a positive temperature coefficient; a reference voltage that is independent of temperature is output between the drain of the sixth MOS transistor and the second resistor; the ninth MOS transistor and the tenth MOS transistor share a common gate; the source of the ninth MOS transistor is connected to the anode of the first diode; the source of the tenth MOS transistor is connected to one end of the first resistor; the other end of the first resistor is respectively connected to the anodes of the N second diodes; the other end of the second resistor is connected to the anode of the third diode; the cathode of the first diode, the cathodes of the N second diodes, and the cathode of the third diode are all grounded.

[0008] As a limitation: the bias module includes a first operational amplifier, an eleventh MOS transistor, a twelfth MOS transistor, a thirteenth MOS transistor, a fourteenth MOS transistor, L fifteenth MOS transistors, L sixteenth MOS transistors, a third resistor, a fourth resistor and a fifth resistor. The reference voltage output by the temperature sensing module is input to the non-inverting input terminal of the first operational amplifier. The output terminal of the first operational amplifier is respectively connected to the gate of the eleventh MOS transistor and the gates of the L fifteenth MOS transistors. The eleventh MOS transistor and the L fifteenth MOS transistors share a common gate. The source of the eleventh MOS transistor, the source of the L fifteenth MOS transistors and the source of the thirteenth MOS transistor are all connected to the power module. The drain of the eleventh MOS transistor is connected to the source of the twelfth MOS transistor. Each fifteenth MOS transistor is connected to the power module. The drains of the OS transistors are all connected to the source of the sixteenth MOS transistor. The L fifteenth MOS transistors correspond to the L sixteenth MOS transistors one-to-one. The drains of the thirteenth MOS transistor are respectively connected to the gate of the thirteenth MOS transistor and the source of the fourteenth MOS transistor. The twelfth MOS transistor, the fourteenth MOS transistor, and the L sixteenth MOS transistors share a gate. The drain of the twelfth MOS transistor is respectively connected to the inverting input terminal of the first operational amplifier and one end of the third resistor. The drain of the fourteenth MOS transistor is respectively connected to the gate of the fourteenth MOS transistor and one end of the fifth resistor. The drains of the L sixteenth MOS transistors are connected to the bias current required by the output module. The other end of the third resistor is connected to one end of the fourth resistor. The other end of the fourth resistor and the other end of the fifth resistor are both grounded.

[0009] As a limitation: the output module includes a second operational amplifier, a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor and a tenth resistor, the power supply module is connected to one end of the ninth resistor, the other end of the ninth resistor is respectively connected to one end of the tenth resistor and the non-inverting input end of the second operational amplifier, the other end of the tenth resistor is grounded, the output voltage of the power supply module generates a bias voltage through resistance voltage division and is input to the non-inverting input end of the second operational amplifier, the bias module provides a bias current for the second operational amplifier, the output end of the second operational amplifier is connected to one end of the sixth resistor, the other end of the sixth resistor is respectively connected to the inverting input end of the second operational amplifier and one end of the seventh resistor, the other end of the seventh resistor is connected to one end of the eighth resistor, the other end of the eighth resistor is grounded, the current with a positive temperature coefficient output by the temperature sensing module is input between the seventh resistor and the eighth resistor, the resistance ratio between the sixth resistor, the seventh resistor and the eighth resistor is adjustable, the resistance ratio between the ninth resistor and the tenth resistor is adjustable, and the output end of the second operational amplifier outputs a controllable voltage with a negative temperature coefficient.

[0010] As a limitation: the power module includes an LDO linear regulator, which converts the input voltage into a stable output voltage.

[0011] Due to the adoption of the above solution, the present invention has the following beneficial effects compared with the prior art:

[0012] The utility model provides a CMOS temperature sensing front-end circuit with an adjustable output voltage range. A temperature sensing module, a bias module, an output module, and a power supply module are provided, which cooperate with each other to convert temperature information into a voltage signal. By adjusting the resistance ratio between resistors in the output module, flexible control of the output voltage range is achieved, thereby improving the accuracy of the temperature sensor. The temperature sensing module utilizes the characteristic that the voltage across a diode changes with temperature to detect temperature. By providing two sets of current mirrors and two resistors, the circuit generates and outputs a current with a positive temperature coefficient, as well as a reference voltage that is independent of temperature. The bias circuit converts the reference voltage into a bias current by providing a first operational amplifier and three resistors, and provides a stable bias current to the output module through a set of current mirrors. The output module converts the current with a positive temperature coefficient into a voltage with a negative temperature coefficient by providing a second operational amplifier circuit and two sets of resistors. By adjusting the resistance ratios between the sixth resistor, the seventh resistor, and the eighth resistor, as well as the resistance ratio between the ninth resistor and the tenth resistor, the circuit achieves flexible control of the output voltage range, thereby improving the accuracy of the temperature sensor. An LDO linear regulator is provided to provide a stable voltage for the temperature sensing module, the bias module, and the output module.

[0013] The utility model is suitable for a temperature sensor system. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments.

[0015] Figure 1 This is a structural block diagram of a CMOS temperature sensing front-end circuit with adjustable output voltage range according to an embodiment of the present invention;

[0016] Figure 2 This is a circuit diagram of the temperature sensing module according to an embodiment of the present utility model;

[0017] Figure 3 This is a circuit diagram of a bias module according to an embodiment of the present utility model;

[0018] Figure 4 This is a circuit diagram of the output module of an embodiment of the utility model;

[0019] Figure 5 This is a simulation result of the output voltage of the output module when the resistance ratios of the resistors in the output module are different according to an embodiment of the present invention. DETAILED DESCRIPTION

[0020] The present invention will be further described below with reference to the following embodiments. However, those skilled in the art should understand that the present invention is not limited to the following embodiments, and any improvements and equivalent changes made based on the specific embodiments of the present invention are within the scope of protection of the claims of the present invention.

[0021] A CMOS temperature sensing front-end circuit with adjustable output voltage range

[0022] A CMOS temperature sensing front-end circuit with adjustable output voltage range, such as Figure 1 As shown, it includes a temperature sensing module, a bias module, an output module and a power module. The power module is connected to the temperature sensing module, the bias module and the output module respectively. The temperature sensing module is connected to the bias module and the output module respectively. The bias module is connected to the output module. The power module provides voltage V for the temperature sensing module, the bias module and the output module. LDO The temperature sensing module detects the temperature and outputs a current with a positive temperature coefficient I temp and a temperature-independent reference voltage V REF , the bias module sets the reference voltage V REF Converted into the bias current I required by the output module bias , the output module will be the positive temperature coefficient of the current I temp Converted into a controllable voltage V with a negative temperature coefficient temp .

[0023] The power module includes an LDO linear regulator, which converts the input voltage into a stable output voltage V LDO .

[0024] like Figure 2 As shown, the temperature sensing module includes a first diode D1, N second diodes D2, a third diode D3, a first resistor R1, a second resistor R2, a first MOS transistor M1, a second MOS transistor M2, a third MOS transistor M3, a fourth MOS transistor M4, a fifth MOS transistor M5, a sixth MOS transistor M6, M seventh MOS transistors M7, M eighth MOS transistors M8, a ninth MOS transistor M9 and a tenth MOS transistor M 10 The source electrodes of the first MOS tube M1, the third MOS tube M3, the fifth MOS tube M5 and the M seventh MOS tubes M7 are all input with the voltage V provided by the LDO linear regulator. LDOThe first MOS transistor M1, the third MOS transistor M3, the fifth MOS transistor M5 and the M seventh MOS transistors M7 share a common gate, the drain of the first MOS transistor M1 is connected to the source of the second MOS transistor M2, the drain of the third MOS transistor M3 is respectively connected to the gate of the third MOS transistor M3 and the source of the fourth MOS transistor M4, the drain of the fifth MOS transistor M5 is connected to the source of the sixth MOS transistor M6, the drain of each seventh MOS transistor M7 is connected to the source of the eighth MOS transistor M8, and the M seventh MOS transistors M7 correspond to the M eighth MOS transistors M8; the second MOS transistor M2, the fourth MOS transistor M4, the sixth MOS transistor M6 and the M eighth MOS transistors M8 share a common gate, the drain of the second MOS transistor M2 is respectively connected to the drain of the ninth MOS transistor M9 and the gate of the ninth MOS transistor M9, the drain of the fourth MOS transistor M4 is respectively connected to the gate of the fourth MOS transistor M4 and the gate of the tenth MOS transistor M 10 The drain of the sixth MOS tube M6 is connected to one end of the second resistor R2, and the drains of the M eighth MOS tubes M8 are connected to output a current I with a positive temperature coefficient. temp A reference voltage V that is independent of temperature is output between the drain of the sixth MOS tube M6 and the second resistor R2. REF ; The ninth MOS tube M9 and the tenth MOS tube M 10 The source of the ninth MOS tube M9 is connected to the anode of the first diode D1, and the tenth MOS tube M 10 The source is connected to one end of the first resistor R1, the other end of the first resistor R1 is connected to the anodes of the N second diodes D2, the other end of the second resistor R2 is connected to the anode of the third diode D3, and the cathode of the first diode D1, the cathodes of the N second diodes D2 and the cathode of the third diode D3 are all grounded.

[0025] The voltage difference between the first diode D1 and the second diode D2 in the temperature sensing module acts on the first resistor R1 to generate a current I with a positive temperature coefficient. ptat , I ptat The calculation formula is:

[0026]

[0027] Where k is the Boltzmann constant, q is the electron charge, and T is the absolute temperature;

[0028] Output current I with positive temperature coefficient through current mirror temp :

[0029]

[0030] Current I in the temperature sensing module ptat The current is mirrored to the branch where the second resistor R2 is located, generating a reference voltage V that is independent of temperature.REF , V REF The calculation formula is:

[0031]

[0032] Where V D3 is the voltage difference across the third diode D3.

[0033] like Figure 3 As shown, the bias module includes a first operational amplifier OP1, an eleventh MOS transistor M 11 , 12th MOS tube M 12 、Thirteenth MOS tube M 13 、Fourteenth MOS tube M 14 、L fifteenth MOS tubes M 15 、L sixteenth MOS tubes M 16 , the third resistor R3, the fourth resistor R4 and the fifth resistor R5, the reference voltage V output by the temperature sensing module REF The first operational amplifier OP1 is input to the non-inverting input terminal, and the output terminal of the first operational amplifier OP1 is connected to the eleventh MOS transistor M 11 The gate and L fifteenth MOS tube M 15 The gate connection of the eleventh MOS tube M 11 and L fifteenth MOS tubes M 15 Common gate, eleventh MOS tube M 11 The source of L fifteenth MOS tubes M 15 The source and the thirteenth MOS tube M 13 The source of the input LDO linear regulator provides a voltage V LDO , the eleventh MOS tube M 11 The drain of the twelfth MOS tube M 12 The source of each fifteenth MOS tube M 15 The drain of the sixteenth MOS tube M 16 The source of L fifteenth MOS tubes M 15 and L sixteenth MOS tubes M 16 One to one correspondence, the thirteenth MOS tube M 13 The drain of the thirteenth MOS tube M 13 The gate and the fourteenth MOS tube M 14 The source of the twelfth MOS tube M 12 、Fourteenth MOS tube M 14 and L sixteenth MOS tubes M 16 Common gate, twelfth MOS tube M 12 The drain of the fourteenth MOS tube M is connected to the inverting input terminal of the first operational amplifier OP1 and one end of the third resistor R3 respectively.14 The drain of the fourteenth MOS tube M 14 The gate of the L sixteenth MOS tube M is connected to one end of the fifth resistor R5. 16 The output module's required bias current I is connected to the drain of the output bias The other end of the third resistor R3 is connected to one end of the fourth resistor R4, and the other end of the fourth resistor R4 and the other end of the fifth resistor R5 are both grounded.

[0034] The reference voltage V is input to the non-inverting input terminal of the first operational amplifier OP1 in the bias module. REF , using the virtual short characteristic of the operational amplifier and the resistor to generate a current, and then output the bias current I through the current mirror bias The third resistor R3 and the fourth resistor R4 can be selected from resistor types with different temperature coefficients to obtain a bias current I that is independent of temperature. bias , I bias The calculation formula is:

[0035]

[0036] like Figure 4 As shown, the output module includes a second operational amplifier OP2, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a ninth resistor R9 and a tenth resistor R 10 The power module is connected to one end of the ninth resistor R9, and the other end of the ninth resistor R9 is connected to the tenth resistor R 10 One end is connected to the non-inverting input terminal of the second operational amplifier OP2, and the tenth resistor R 10 The other end is grounded, and the voltage V LDO Generate bias voltage V through resistor divider bias Input to the non-inverting input terminal of the second operational amplifier OP2, the bias module provides a bias current I for the second operational amplifier OP2 bias The output end of the second operational amplifier OP2 is connected to one end of the sixth resistor R6, the other end of the sixth resistor R6 is respectively connected to the inverting input end of the second operational amplifier OP2 and one end of the seventh resistor R7, the other end of the seventh resistor R7 is connected to one end of the eighth resistor R8, the other end of the eighth resistor R8 is grounded, and the positive temperature coefficient current I output by the temperature sensing module is input between the seventh resistor R7 and the eighth resistor R8. temp The resistance ratio between the sixth resistor R6, the seventh resistor R7 and the eighth resistor R8 is adjustable, and the ninth resistor R9 and the tenth resistor R 10 The resistance ratio between them is adjustable, and the output end of the second operational amplifier OP2 outputs a controllable voltage V with a negative temperature coefficient. temp .

[0037] The output voltage V of the LDO linear regulator in the output module LDO The ninth resistor R9 and the tenth resistor R 10 The bias voltage V is generated by voltage division bias , bias voltage V bias Input to the non-inverting input terminal of the second operational amplifier OP2, the bias module provides a bias current I for the second operational amplifier OP2 bias , the current I output by the temperature sensing module temp The voltage V with a negative temperature coefficient and adjustable voltage range is obtained by the calculation of the second operational amplifier OP2. temp ,V temp The calculation formula is:

[0038]

[0039] Where, Then I temp Substitute the calculation formula into the above formula and get:

[0040]

[0041] From the above formula, we can see that the output voltage V temp Inversely proportional to the absolute temperature T, so V temp The change of the current temperature can be used to indicate the change of the current temperature, and the resistance ratio of the sixth resistor R6, the seventh resistor R7 and the eighth resistor R8 is adjusted, and the ninth resistor R9 and the tenth resistor R 10 The resistance ratio between them is used to achieve the output voltage V temp Range control.

[0042] like Figure 5 As shown in (a), when R6:R7:R8=a:b:c, R6:R7:R8=2a:b:c, and R6:R7:R8=a:2b:c, the output voltage of the output module is V temp The simulation results from Figure 5 As can be seen from (a), when the resistance ratio of the sixth resistor R6 increases, the output voltage V temp The range becomes larger, when the resistance ratio of the seventh resistor R7 increases, the output voltage V temp The range becomes smaller. Figure 5 (b) shows different V bias When the ninth resistor R9 and the tenth resistor R 10 When the resistance ratio is different, the output module output voltage V temp The simulation results from Figure 5 As can be seen from (b), the output voltage V temp The range will vary with V biasAs V bias becomes smaller and moves downward.

Claims

1. A CMOS temperature sensing front-end circuit with adjustable output voltage range, characterized in that: It includes a temperature sensing module, a bias module, an output module and a power module. The power module is connected to the temperature sensing module, the bias module and the output module respectively. The temperature sensing module is connected to the bias module and the output module respectively. The bias module is connected to the output module. The power module provides voltage to the temperature sensing module, bias module and output module. The temperature sensing module detects temperature and outputs a current with a positive temperature coefficient and a reference voltage that is independent of temperature. The bias module converts the reference voltage into the bias current required by the output module. The output module converts the current with a positive temperature coefficient into a controllable voltage with a negative temperature coefficient.

2. The CMOS temperature sensing front-end circuit with adjustable output voltage range according to claim 1, characterized in that: The temperature sensing module includes a first diode, N second diodes, a third diode, a first resistor, a second resistor, a first MOS tube, a second MOS tube, a third MOS tube, a fourth MOS tube, a fifth MOS tube, a sixth MOS tube, M seventh MOS tubes, M eighth MOS tubes, a ninth MOS tube and a tenth MOS tube; the sources of the first MOS tube, the third MOS tube, the fifth MOS tube and the M seventh MOS tubes are all connected to the power module, the first MOS tube, the third MOS tube, the fifth MOS tube and the M seventh MOS tubes share a gate, the drain of the first MOS tube is connected to the source of the second MOS tube, the drain of the third MOS tube is respectively connected to the gate of the third MOS tube and the source of the fourth MOS tube, the drain of the fifth MOS tube is connected to the source of the sixth MOS tube, the drain of each seventh MOS tube is connected to the source of the eighth MOS tube, and the M seventh MOS tubes correspond one to one to the M eighth MOS tubes; The second MOS transistor, the fourth MOS transistor, the sixth MOS transistor, and the M eighth MOS transistors share a common gate; the drain of the second MOS transistor is respectively connected to the drain of the ninth MOS transistor and the gate of the ninth MOS transistor; the drain of the fourth MOS transistor is respectively connected to the gate of the fourth MOS transistor and the drain of the tenth MOS transistor; the drain of the sixth MOS transistor is connected to one end of the second resistor; the drains of the M eighth MOS transistors are connected to output a current with a positive temperature coefficient; a reference voltage independent of temperature is output between the drain of the sixth MOS transistor and the second resistor; the ninth MOS transistor and the tenth MOS transistor share a common gate; the source of the ninth MOS transistor is connected to the anode of the first diode; the source of the tenth MOS transistor is connected to one end of the first resistor; the other end of the first resistor is respectively connected to the anodes of the N second diodes; the other end of the second resistor is connected to the anode of the third diode; the cathode of the first diode, the cathodes of the N second diodes, and the cathode of the third diode are all grounded.

3. A CMOS temperature sensing front-end circuit with adjustable output voltage range according to claim 1 or 2, characterized in that: The bias module includes a first operational amplifier, an eleventh MOS tube, a twelfth MOS tube, a thirteenth MOS tube, a fourteenth MOS tube, L fifteenth MOS tubes, L sixteenth MOS tubes, a third resistor, a fourth resistor, and a fifth resistor. The reference voltage output by the temperature sensing module is input to the non-inverting input terminal of the first operational amplifier. The output terminal of the first operational amplifier is respectively connected to the gate of the eleventh MOS tube and the gate of the L fifteenth MOS tubes. The eleventh MOS tube and the L fifteenth MOS tubes share a common gate. The source of the eleventh MOS tube, the source of the L fifteenth MOS tubes, and the source of the thirteenth MOS tube are all connected to the power module. The drain of the eleventh MOS tube is connected to the source of the twelfth MOS tube. The drain of each fifteenth MOS tube is connected to the source of the 12th MOS tube. The drains of the L fifteenth MOS transistors are connected to the source of the sixteenth MOS transistor. The L fifteenth MOS transistors correspond to the L sixteenth MOS transistors one-to-one. The drain of the thirteenth MOS transistor is respectively connected to the gate of the thirteenth MOS transistor and the source of the fourteenth MOS transistor. The twelfth MOS transistor, the fourteenth MOS transistor, and the L sixteenth MOS transistors share a gate. The drain of the twelfth MOS transistor is respectively connected to the inverting input terminal of the first operational amplifier and one end of the third resistor. The drain of the fourteenth MOS transistor is respectively connected to the gate of the fourteenth MOS transistor and one end of the fifth resistor. The drains of the L sixteenth MOS transistors are connected to the bias current required by the output module. The other end of the third resistor is connected to one end of the fourth resistor. The other end of the fourth resistor and the other end of the fifth resistor are both grounded.

4. A CMOS temperature sensing front-end circuit with adjustable output voltage range according to claim 1 or 2, characterized in that: The output module includes a second operational amplifier, a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor and a tenth resistor. The power supply module is connected to one end of the ninth resistor, the other end of the ninth resistor is respectively connected to one end of the tenth resistor and the non-inverting input end of the second operational amplifier, and the other end of the tenth resistor is grounded. The output voltage of the power supply module generates a bias voltage through resistance voltage division and is input to the non-inverting input end of the second operational amplifier. The bias module provides a bias current for the second operational amplifier. The output end of the second operational amplifier is connected to one end of the sixth resistor, the other end of the sixth resistor is respectively connected to the inverting input end of the second operational amplifier and one end of the seventh resistor, the other end of the seventh resistor is connected to one end of the eighth resistor, and the other end of the eighth resistor is grounded. The current with a positive temperature coefficient output by the temperature sensing module is input between the seventh resistor and the eighth resistor. The resistance ratio between the sixth resistor, the seventh resistor and the eighth resistor is adjustable, and the resistance ratio between the ninth resistor and the tenth resistor is adjustable. The output end of the second operational amplifier outputs a controllable voltage with a negative temperature coefficient.

5. A CMOS temperature sensing front-end circuit with adjustable output voltage range according to claim 1 or 2, characterized in that: The power module includes an LDO linear regulator, which converts the input voltage into a stable output voltage.

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