Temperature sampling circuit

Abstract

The utility model provides a temperature sampling circuit, and relates to the technical field of temperature sampling. As the temperature sampling resistor is connected in series with the first resistor, one end of the formed series branch is connected with the first power supply, and the other end is grounded, and the second resistor is connected in series with the third resistor, one end of the formed series branch is connected with the first power supply, and the other end is grounded. The temperature sampling circuit, the first resistor, the second resistor and the third resistor form a bridge voltage division circuit, so that the formed bridge voltage division circuit provides differential voltage for the differential amplification circuit, and the differential amplification circuit can be used for differential amplification. Therefore, the same parts in the two output signals forming the bridge voltage division circuit can be counteracted to a certain extent, namely, a part of errors can be counteracted, and the sampling precision of the temperature sampling circuit is further improved. Therefore, if the temperature sampling circuit is used as a temperature monitoring device of the motor, namely temperature sampling is carried out on the motor, the sampling precision of the temperature of the motor is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to temperature sampling technical field especially relates to a temperature sampling circuit. BACKGROUND

[0002] With the high -speed development of new energy automobile, more and more host factory to motor performance requirement is higher and higher. In order to improve the operating efficiency of motor, must effectively monitor motor temperature, specifically, in high speed low current, low speed large current, need more accurate detection motor temperature.

[0003] After detecting motor temperature, can judge the state of motor in the process of vehicle driving according to motor temperature, so as to effectively protect motor in the case of abnormal motor temperature. However, at present, the sampling precision of motor temperature is low, thereby leading to the easy occurrence of false protection of motor, and further causing the influence on the normal driving of vehicle.

[0004] Therefore, how to improve the sampling precision of motor temperature is a technical problem to be solved. UTILITY MODEL CONTENT

[0005] Therefore, the utility model provides a temperature sampling circuit to improve the sampling precision of motor temperature.

[0006] To achieve the above object, the utility model embodiment provides the following technical scheme:

[0007] The application provides a temperature sampling circuit, comprising: a temperature sampling resistor, a differential amplification circuit, a first resistor, a second resistor and a third resistor, wherein:

[0008] The temperature sampling resistor and the first resistor are connected in series, one end of the series branch formed by the temperature sampling resistor and the first resistor is connected with a first power supply, and the other end is grounded.

[0009] The connection point of the temperature sampling resistor and the first resistor is connected with the non-inverting input terminal of the differential amplification circuit.

[0010] The second resistor and the third resistor are connected in series, one end of the series branch formed by the second resistor and the third resistor is connected with the first power supply, and the other end is grounded.

[0011] The connection point of the second resistor and the third resistor is connected with the inverting input terminal of the differential amplification circuit.

[0012] The output terminal of the differential amplification circuit serves as the output terminal of the temperature sampling circuit.

[0013] Optionally, the differential amplification circuit comprises an operational amplifier, a fourth resistor, a fifth resistor, a sixth resistor and a seventh resistor, wherein:

[0014] One end of the fourth resistor is connected to the non-inverting input terminal of the differential amplifier circuit, and the other end of the fourth resistor is connected to the non-inverting input terminal of the operational amplifier;

[0015] One end of the fifth resistor is connected to the inverting input terminal of the differential amplifier circuit, and the other end of the fifth resistor is connected to the inverting input terminal of the operational amplifier;

[0016] One end of the sixth resistor is connected to the non-inverting input terminal of the operational amplifier;

[0017] The other end of the sixth resistor is connected to the ground, or the other end of the sixth resistor is connected to the output terminal of the bias power supply;

[0018] One end of the seventh resistor is connected to the inverting input terminal of the operational amplifier, and the other end of the seventh resistor is connected to the output terminal of the operational amplifier;

[0019] The output terminal of the operational amplifier is connected to the output terminal of the differential amplifier circuit.

[0020] Optionally, the bias power supply comprises a linear voltage stabilizer, an eighth resistor and a ninth resistor; wherein:

[0021] The anode of the linear voltage stabilizer is connected to the ground, and the cathode of the linear voltage stabilizer is connected to the second power supply;

[0022] One end of the eighth resistor is connected to the cathode of the linear voltage stabilizer;

[0023] One end of the ninth resistor is connected to the anode of the linear voltage stabilizer;

[0024] The other end of the eighth resistor is connected to the other end of the ninth resistor, and the connection point is connected to the reference electrode of the linear voltage stabilizer;

[0025] The reference electrode of the linear voltage stabilizer is connected to the output terminal of the bias power supply.

[0026] Optionally, the bias power supply further comprises a first capacitor; wherein:

[0027] One end of the first capacitor is connected to the reference electrode of the linear voltage stabilizer, and the other end of the first capacitor is connected to the ground.

[0028] Optionally, the differential amplifier circuit further comprises a second capacitor, a third capacitor and / or a fourth capacitor; wherein:

[0029] One end of the second capacitor is connected to the non-inverting input terminal of the operational amplifier, and the other end of the second capacitor is connected to the ground;

[0030] One end of the third capacitor is connected with the inverting input terminal of the operational amplifier, and the other end of the third capacitor is grounded.

[0031] One end of the fourth capacitor is connected with the non-inverting input terminal of the operational amplifier, and the other end of the fourth capacitor is connected with the inverting input terminal of the operational amplifier.

[0032] Optionally, the differential amplification circuit further comprises a fifth capacitor, wherein:

[0033] The fifth capacitor is connected in parallel with the seventh resistor.

[0034] Optionally, the differential amplification circuit further comprises a low-pass filter circuit, wherein:

[0035] One end of the differential amplification circuit is connected with one end of the low-pass filter circuit, and the other end of the low-pass filter circuit serves as an output terminal of the temperature sampling circuit.

[0036] Optionally, the low-pass filter circuit comprises a tenth resistor and a sixth capacitor, wherein:

[0037] One end of the tenth resistor is connected with one end of the sixth capacitor, and the connection point serves as one end of the low-pass filter circuit.

[0038] The other end of the tenth resistor serves as the other end of the low-pass filter circuit.

[0039] The other end of the sixth capacitor is grounded.

[0040] Optionally, the differential amplification circuit further comprises a first diode and / or a second diode, wherein:

[0041] The cathode of the first diode is connected with the output terminal of the temperature sampling circuit, and the anode of the first diode is grounded.

[0042] The anode of the second diode is connected with the output terminal of the temperature sampling circuit, and the cathode of the second diode is connected with a third power supply.

[0043] Optionally, the temperature sampling resistor serves as a temperature monitoring device of a motor.

[0044] The utility model provides a temperature sampling circuit, which is connected in series with the temperature sampling resistor and the first resistor, with one end of the series branch connected to the first power supply and the other end grounded, and the second resistor and the third resistor connected in series, with one end of the series branch connected to the first power supply and the other end grounded. Therefore, the temperature sampling circuit, the first resistor, the second resistor and the third resistor form a bridge voltage divider circuit, which provides differential voltage for the differential amplifier circuit. Thus, the differential amplifier circuit can be used for differential amplification, which can offset the same part of the two output signals of the bridge voltage divider circuit to some extent, i.e. to offset part of the error, thereby improving the sampling accuracy of the temperature sampling circuit. Therefore, if the temperature sampling circuit is used as a temperature monitoring device for the motor, i.e. to sample the temperature of the motor, the sampling accuracy of the motor temperature can be improved. BRIEF DESCRIPTION OF DRAWINGS

[0045] To more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed in the embodiments or the prior art description will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative effort on the basis of the provided drawings.

[0046] Figure 1 and Figure 2 are structural schematic diagrams of two embodiments of the temperature sampling circuit provided by the embodiments of the present application, respectively;

[0047] Figure 3 and Figure 4 are structural schematic diagrams of two embodiments of the bias power supply 12 provided by the embodiments of the present application, respectively;

[0048] Figures 5-12 are structural schematic diagrams of eight other embodiments of the temperature sampling circuit provided by the embodiments of the present application, respectively. DETAILED DESCRIPTION

[0049] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative effort fall within the scope of the present application.

[0050] In this application, the terms such as first and second are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between such entities or operations. Also, the terms "comprises", "comprising", or any other variations thereof are intended to cover non-exclusive inclusions, so that a process, method, article, or apparatus that comprises a list of elements does not only include those elements, but can also include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without more limitations, the element defined by the phrase "comprises a" does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes the element.

[0051] In order to improve the sampling accuracy of the motor temperature, the embodiment of the application provides a temperature sampling circuit, and the specific structure is as shown in Figure 1 or Figure 2 The temperature sampling circuit specifically comprises a temperature sampling resistor RT, a differential amplification circuit 10, a first resistor R1, a second resistor R2, and a third resistor R3. The connection relationship between the devices is specifically described as follows.

[0052] The temperature sampling resistor RT and the first resistor R1 are connected in series, and one end of the series branch is connected with the first power supply 01 and the other end is grounded.

[0053] The connection point of the temperature sampling resistor RT and the first resistor R1 is connected with the non-inverting input end of the differential amplification circuit 10.

[0054] In a specific example, the temperature sampling resistor RT is used as a temperature monitoring device of the motor, that is, the temperature sampling circuit provided by the application samples the temperature of the motor.

[0055] The above example only shows one embodiment of the sampling object of the temperature sampling resistor RT, and in actual application, it includes but is not limited to this, which is not specifically limited here, and can be determined according to the specific situation, all of which are within the protection scope of the application.

[0056] The second resistor R2 and the third resistor R3 are connected in series, and one end of the series branch is connected with the first power supply 01 and the other end is grounded. Usually, the controller corresponding to the temperature sampling circuit has a collection range of 0-5V, so the output voltage of the first power supply 01 is 5V.

[0057] The connection point of the second resistor R2 and the third resistor R3 is connected with the inverting input end of the differential amplification circuit 10.

[0058] The output end of the differential amplification circuit 10 is used as the output end of the temperature sampling circuit.

[0059] As can be known from the connection relationship of the temperature sampling resistor RT, the first resistor R1, the second resistor R2 and the third resistor R3, the temperature sampling resistor RT, the first resistor R1, the second resistor R2 and the third resistor R3 form a bridge voltage dividing circuit.

[0060] Since the connection point of the temperature sampling resistor RT and the first resistor R1 is connected with the non-inverting input terminal of the differential amplification circuit 10, and the connection point of the second resistor R2 and the third resistor R3 is connected with the inverting input terminal of the differential amplification circuit 10, the bridge voltage dividing circuit provides a differential voltage for the differential amplification circuit 10.

[0061] Specifically, as the temperature of the sampling object of the temperature sampling resistor RT changes, the resistance of the temperature sampling resistor RT also changes, and the changed resistance and the first resistor R1 form a voltage dividing circuit to obtain a differential input positive voltage; in addition, the second resistor R2 and the third resistor R3 also form another voltage dividing circuit to obtain a differential input negative voltage. The differential input positive voltage minus the differential input negative voltage obtains the differential voltage of the differential amplification circuit 10. After the differential voltage is amplified by the differential amplification circuit 10, it is input into the corresponding controller of the temperature sampling circuit in the form of a voltage signal. The controller can obtain the corresponding temperature by looking up the table according to the voltage signal received by itself, that is, the temperature of the sampling object of the temperature sampling resistor RT, that is, the temperature sampling of the sampling object of the temperature sampling circuit is realized.

[0062] Since the temperature sampling resistor RT and the first resistor R1 are connected in series, one end of the series branch is connected with the first power supply 01 and the other end is grounded, and the second resistor R2 and the third resistor R3 are connected in series, one end of the series branch is connected with the first power supply 01 and the other end is grounded, so the temperature sampling circuit, the first resistor R1, the second resistor R2 and the third resistor R3 form a bridge voltage dividing circuit, and the bridge voltage dividing circuit provides a differential voltage for the differential amplification circuit 10, so that the differential amplification circuit 10 can be used for differential amplification, so that the same part of the two output signals of the bridge voltage dividing circuit can be offset to a certain extent, that is, a part of the error can be offset, and the sampling accuracy of the temperature sampling circuit is improved. Therefore, if the temperature sampling circuit is used as a temperature monitoring device of the motor, that is, the temperature of the motor is sampled, the sampling accuracy of the motor temperature is improved.

[0063] Another embodiment of the temperature sampling circuit is provided in the present application, which is different from the previous embodiment in that:

[0064] In this embodiment, the temperature sampling resistor RT is PT1000.

[0065] Since the temperature measurement range of PT1000 is generally between -200℃ and 600℃, the temperature measurement range is wide, so if the temperature sampling circuit samples the temperature of the motor, the temperature measurement requirement of the motor can be met.

[0066] In addition, since the linearity of PT1000 is very good, the precision is high, and the response speed is fast, for example, the precision can generally reach 0.1℃, so the temperature sampling resistor RT adopts PT1000, which can further improve the sampling precision of the temperature sampling circuit.

[0067] Another embodiment of the present application provides a specific implementation of the differential amplification circuit 10, which has a specific structure as shown in Figure 1 or Figure 2 The specific implementation of the differential amplification circuit 10 includes an operational amplifier 11, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, and a seventh resistor R7. The connection relationship between the devices is described as follows:

[0068] One end of the fourth resistor R4 is the non-inverting input terminal of the differential amplification circuit 10, and the other end of the fourth resistor R4 is connected to the non-inverting input terminal of the operational amplifier 11. One end of the fifth resistor R5 is the inverting input terminal of the differential amplification circuit 10, and the other end of the fifth resistor R5 is connected to the inverting input terminal of the operational amplifier 11. The fourth resistor R4 and the fifth resistor R5 provide differential input impedance for the input of the operational amplifier 11.

[0069] In a specific example, as shown in Figure 1 the other end of the sixth resistor R6 is grounded.

[0070] In another specific example, as shown in Figure 2 the other end of the sixth resistor R6 is connected to the output terminal of the bias power supply 12. In actual application, the output voltage of the bias power supply 12 can be adjusted according to actual needs. If the output voltage of the first power supply 01 is 5V, the output voltage of the bias power supply 12 is 2.5V.

[0071] It should be noted that if the other end of the sixth resistor R6 is grounded, the differential amplification circuit 10 only amplifies the differential voltage without biasing, and if the other end of the sixth resistor R6 is connected to the output terminal of the bias power supply 12, the differential amplification circuit 10 first amplifies the differential voltage, and then biases the amplified voltage, that is, the amplified voltage is added to the output voltage of the bias power supply 12, such as 2.5V.

[0072] The above two examples show two connection modes of the sixth resistor R6, and in actual application, they include but are not limited to this, which is not limited here, and can be determined according to the specific situation, and all are within the protection scope of the present application.

[0073] One end of the sixth resistor R6 is connected to the non-inverting input terminal of the operational amplifier 11. One end of the seventh resistor R7 is connected to the inverting input terminal of the operational amplifier 11, and the other end of the seventh resistor R7 is connected to the output terminal of the operational amplifier 11. The output terminal of the operational amplifier 11 serves as the output terminal of the differential amplification circuit 10. The sixth resistor R6 and the seventh resistor R7 provide gain amplification for the preamplifier, and specifically, the amplification gain is equal to the seventh resistor R7 divided by the sixth resistor R6.

[0074] The above is only one specific embodiment of the differential amplification circuit 10, and in actual applications, including but not limited to this, this is not specifically limited here, and can be determined according to the specific circumstances, all within the protection scope of the present application.

[0075] Another embodiment of the present application provides a specific embodiment of the bias power supply 12, and the specific structure is as shown in Figure 3 The bias power supply 12 specifically includes a linear voltage regulator power supply 121, an eighth resistor R8, and a ninth resistor R9. The connection relationship between the devices is specifically described as follows:

[0076] The anode of the linear voltage regulator power supply 121 is grounded, and the cathode of the linear voltage regulator power supply 121 is connected to the second power supply 02. If the output voltage of the bias power supply 12 is 2.5V, then the output voltage of the second power supply 02 is usually 5V.

[0077] One end of the eighth resistor R8 is connected to the cathode of the linear voltage regulator power supply 121.

[0078] One end of the ninth resistor R9 is connected to the anode of the linear voltage regulator power supply 121.

[0079] The other end of the eighth resistor R8, the other end of the ninth resistor R9, and the reference terminal of the linear voltage regulator power supply 121 are all connected, and the connection point serves as the output terminal of the bias power supply 12.

[0080] The eighth resistor R8 and the ninth resistor R9 constitute a voltage divider circuit, and the voltage division of the ninth resistor R9 adjusts the output of the linear voltage regulator power supply 121, that is, adjusts the cathode potential of the linear voltage regulator power supply 121, thereby changing the voltage division of the eighth resistor R8 and the ninth resistor R9, and further changing the output voltage of the bias power supply 12, that is, adjusting the output voltage of the bias power supply 12.

[0081] The above is only one specific embodiment of the bias power supply 12, and in actual applications, including but not limited to this, this is not specifically limited here, and can be determined according to the specific circumstances, all within the protection scope of the present application.

[0082] Another embodiment of the present application provides another embodiment of the bias power supply 12, and the specific structure is as shown in Figure 4As shown in the figure, this embodiment is based on the previous embodiment, and further includes a first capacitor C1. The connection relationship between the devices is described as follows:

[0083] One end of the first capacitor C1 is connected to the reference pole of the linear voltage regulator 121, and the other end of the first capacitor C1 is grounded. Specifically, the first capacitor C1 functions as a filter.

[0084] In this embodiment, since the first capacitor C1 can filter, the quality of its own output and the stability of its own output are improved.

[0085] The above is only another specific embodiment of the bias power supply 12. In actual applications, including but not limited to this, this is not specifically limited here, and can be determined according to the specific circumstances, all within the protection scope of the present application.

[0086] Another embodiment of the present application provides another embodiment of the differential amplification circuit 10, and the specific structure is as shown in the figure Figure 5 or Figure 6 As shown in the figure, this embodiment is based on any one of the above embodiments, and further includes a second capacitor C2 and a third capacitor C3. The connection relationship between the devices is described as follows:

[0087] One end of the second capacitor C2 is connected to the non-inverting input terminal of the operational amplifier 11, and the other end of the second capacitor C2 is grounded.

[0088] One end of the third capacitor C3 is connected to the inverting input terminal of the operational amplifier 11, and the other end of the third capacitor C3 is grounded.

[0089] Since one end of the second capacitor C2 is connected to the non-inverting input terminal of the operational amplifier 11, and the other end of the second capacitor C2 is grounded, one end of the third capacitor C3 is connected to the inverting input terminal of the operational amplifier 11, and the other end of the third capacitor C3 is grounded, the second capacitor C2 and the third capacitor C3 can suppress the common-mode interference of the operational amplifier 11, thereby improving the output accuracy of the differential sampling circuit, and further improving the sampling accuracy of the temperature sampling circuit. Therefore, if the temperature sampling circuit is used as a temperature monitoring device of the motor, that is, the motor is temperature sampled, the sampling accuracy of the motor temperature is further improved.

[0090] The above is only another specific embodiment of the differential amplification circuit 10. In actual applications, including but not limited to this, this is not specifically limited here, and can be determined according to the specific circumstances, all within the protection scope of the present application.

[0091] Another embodiment of the present application provides another embodiment of the differential amplification circuit 10, and the specific structure is as shown in the figure Figure 5 or Figure 6As shown in the figure, this embodiment is based on any one of the above embodiments, and further includes a fourth capacitor C4. The connection relationship between the devices is described as follows:

[0092] One end of the fourth capacitor C4 is connected to the non-inverting input terminal of the operational amplifier 11, and the other end of the fourth capacitor C4 is connected to the inverting input terminal of the operational amplifier 11.

[0093] Since one end of the fourth capacitor C4 is connected to the non-inverting input terminal of the operational amplifier 11, and the other end of the fourth capacitor C4 is connected to the inverting input terminal of the operational amplifier 11, the fourth capacitor C4 can suppress the differential mode interference of the operational amplifier 11, thereby improving the accuracy of the output of the differential sampling circuit, and further improving the sampling accuracy of the temperature sampling circuit. Therefore, if the temperature sampling circuit is used as a temperature monitoring device of the motor, i.e., the motor is temperature-sampled, the sampling accuracy of the motor temperature can be further improved by this embodiment.

[0094] The above is only another specific embodiment of the differential amplification circuit 10, and in actual application, includes but is not limited to this, which is not specifically limited here, and can be determined according to specific conditions, and is within the protection scope of the present application.

[0095] Another embodiment of the present application provides still another embodiment of the differential amplification circuit 10, and the specific structure is as shown in the figure: Figure 7 or Figure 8 As shown in the figure, this embodiment is based on any one of the above embodiments, and further includes a fifth capacitor C5. The connection relationship between the devices is described as follows:

[0096] The fifth capacitor C5 is connected in parallel with the seventh resistor R7. Specifically, the fifth capacitor C5 is a filter capacitor, which filters the feedback between the output terminal and the inverting input terminal of the operational amplifier 11.

[0097] Since the fifth capacitor C5 can filter the feedback between the output terminal and the inverting input terminal of the operational amplifier 11, the accuracy of the output of the differential sampling circuit can be improved, thereby further improving the sampling accuracy of the temperature sampling circuit. Therefore, if the temperature sampling circuit is used as a temperature monitoring device of the motor, i.e., the motor is temperature-sampled, the sampling accuracy of the motor temperature can be further improved by this embodiment.

[0098] The above is only another specific embodiment of the differential amplification circuit 10, and in actual application, includes but is not limited to this, which is not specifically limited here, and can be determined according to specific conditions, and is within the protection scope of the present application.

[0099] Another embodiment of the present application provides still another embodiment of the differential amplification circuit 10, and the specific structure is as shown in the figure: Figure 9 or Figure 10As shown in the figure, this embodiment is based on any one of the above embodiments, and further includes a low-pass filter circuit 20. The connection relationship between the devices is described as follows:

[0100] The output end of the differential amplification circuit 10 is connected to one end of the low-pass filter circuit 20, and the other end of the low-pass filter circuit 20 serves as the output end of the temperature sampling circuit.

[0101] In this embodiment, by adding the low-pass filter circuit 20, low-pass filtering of the signal output by the differential amplification circuit 10 is realized, so that the accuracy of the output of the differential amplification circuit 10 can be improved, thereby further improving the sampling accuracy of the temperature sampling circuit. Therefore, if the temperature sampling circuit is used as a temperature monitoring device of the motor, i.e., to sample the temperature of the motor, this embodiment can further improve the sampling accuracy of the motor temperature.

[0102] The above is only another specific embodiment of the differential amplification circuit 10, and in actual application, includes but is not limited to this, which is not specifically limited here, and can be determined according to the specific situation, all within the protection scope of the present application.

[0103] Another embodiment of the present application provides a specific embodiment of the low-pass filter circuit 20, and the specific structure is as shown in the figure Figure 9 or Figure 10 As shown in the figure, it specifically includes a tenth resistor R10 and a sixth capacitor C6. The connection relationship between the devices is described as follows:

[0104] One end of the tenth resistor R10 is connected to one end of the sixth capacitor C6, and the connection point serves as one end of the low-pass filter circuit. The other end of the tenth resistor R10 serves as the other end of the low-pass filter circuit 20. The other end of the sixth capacitor C6 is grounded.

[0105] The above is only a specific embodiment of the low-pass filter circuit 20, and in actual application, includes but is not limited to this, which is not specifically limited here, and can be determined according to the specific situation, all within the protection scope of the present application.

[0106] Another embodiment of the present application provides another specific embodiment of the temperature sampling circuit, and the specific structure can be referred to Figure 11 or Figure 12 ( Figure 11 , Figure 12 Only the first diode D1 and the second diode D2 are taken as an example for display). This embodiment is based on any one of the above embodiments, and further includes a first diode D1 and / or a second diode D2. The connection relationship between the devices is described as follows:

[0107] The cathode of the first diode D1 is connected to the output end of the temperature sampling circuit, and the anode of the first diode D1 is grounded.

[0108] The anode of the second diode D2 is connected to the output terminal of the temperature sampling circuit, and the cathode of the second diode D2 is connected to the third power supply 03. If the output voltage of the first power supply 01 is 5V, the output voltage of the third power supply 03 is 5V.

[0109] In the embodiment, as can be known from the connection relationship of the first diode D1, when the output voltage of the temperature sampling circuit is relatively high, the first diode D1 can be reversely broken down to discharge the output of the temperature sampling circuit to the ground. As can be known from the connection relationship of the second diode D2, when the output voltage of the temperature sampling circuit is relatively low, the second diode D2 can be reversely broken down to supplement the output of the temperature sampling circuit. In summary, the first diode D1 and the second diode D2 can improve the stability of the output of the temperature sampling circuit, in other words, can improve the anti-interference ability of the temperature sampling circuit.

[0110] The above is only one specific embodiment of the temperature sampling circuit, and in actual application, includes but is not limited to this, which is not specifically limited here, and can be determined according to the specific situation, and is within the protection scope of the present application.

[0111] The above description of the disclosed embodiments, the features recorded in each embodiment in the description can be replaced or combined with each other, so that the person skilled in the art can realize or use the present application. The above is only the preferred embodiment of the present application, and does not limit the present application in any form. Although the present application has been disclosed as the above preferred embodiment, it is not intended to limit the present application. Any person skilled in the art, without departing from the technical solution of the present application, can make many possible changes and modifications to the technical solution of the present application, or modify the equivalent embodiments of equivalent changes. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present application, all still belong to the protection scope of the technical solution of the present application.

Claims

1. A temperature sampling circuit, characterized by, The temperature sampling resistor, the differential amplification circuit, the first resistor, the second resistor and the third resistor are connected in series, one end of the series branch is connected with the first power supply, and the other end is grounded. The connection point of the temperature sampling resistor and the first resistor is connected with the non-inverting input terminal of the differential amplification circuit. The second resistor and the third resistor are connected in series, one end of the series branch is connected with the first power supply, and the other end is grounded. The connection point of the second resistor and the third resistor is connected with the inverting input terminal of the differential amplification circuit. The output terminal of the differential amplification circuit serves as the output terminal of the temperature sampling circuit. The differential amplification circuit comprises an operational amplifier, a fourth resistor, a fifth resistor, a sixth resistor and a seventh resistor. One end of the fourth resistor serves as the non-inverting input terminal of the differential amplification circuit, and the other end of the fourth resistor is connected with the non-inverting input terminal of the operational amplifier.

2. The temperature sampling circuit of claim 1, wherein, One end of the fifth resistor serves as the inverting input terminal of the differential amplification circuit, and the other end of the fifth resistor is connected with the inverting input terminal of the operational amplifier. One end of the sixth resistor is connected with the non-inverting input terminal of the operational amplifier. The other end of the sixth resistor is grounded, or the other end of the sixth resistor is connected with the output terminal of the bias power supply. One end of the seventh resistor is connected with the inverting input terminal of the operational amplifier, and the other end of the seventh resistor is connected with the output terminal of the operational amplifier. The output terminal of the operational amplifier serves as the output terminal of the differential amplification circuit. The bias power supply comprises a linear voltage stabilizing power supply, an eighth resistor and a ninth resistor. The anode of the linear voltage stabilizing power supply is grounded, and the cathode of the linear voltage stabilizing power supply is connected with the second power supply.

3. The temperature sampling circuit of claim 2, wherein, One end of the eighth resistor is connected with the cathode of the linear voltage stabilizing power supply. One end of the ninth resistor is connected with the anode of the linear voltage stabilizing power supply. The other end of the eighth resistor is connected with the other end of the ninth resistor, and the connection point is connected with the reference electrode of the linear voltage stabilizing power supply. The reference electrode of the linear voltage stabilizing power supply serves as the output terminal of the bias power supply. The bias power supply further comprises a first capacitor. One end of the first capacitor is connected with the reference electrode of the linear voltage stabilizing power supply, and the other end of the first capacitor is grounded.

4. The temperature sampling circuit of claim 3, wherein, The differential amplification circuit further comprises a second capacitor, a third capacitor and / or a fourth capacitor. One end of the second capacitor is connected with the non-inverting input terminal of the operational amplifier, and the other end of the second capacitor is grounded.

5. The temperature sampling circuit of claim 2, wherein, One end of the third capacitor is connected with the inverting input terminal of the operational amplifier, and the other end of the third capacitor is grounded. One end of the fourth capacitor is connected with the non-inverting input terminal of the operational amplifier, and the other end of the fourth capacitor is connected with the inverting input terminal of the operational amplifier. The differential amplification circuit further comprises a fifth capacitor. The fifth capacitor is connected in parallel with the seventh resistor.

6. The temperature sampling circuit of claim 2, wherein, The low-pass filter circuit further comprises a tenth resistor and an eleventh resistor. ​ 7. The temperature sampling circuit of any one of claims 1 to 6, wherein, ​ ​ An output end of the differential amplification circuit is connected with one end of the low-pass filter circuit, and the other end of the low-pass filter circuit serves as an output end of the temperature sampling circuit.

8. The temperature sampling circuit of claim 7, wherein, The low-pass filter circuit comprises a tenth resistor and a sixth capacitor. One end of the tenth resistor is connected with one end of the sixth capacitor, and a connection point serves as one end of the low-pass filter circuit. The other end of the tenth resistor serves as the other end of the low-pass filter circuit. The other end of the sixth capacitor is grounded.

9. The temperature sampling circuit of any one of claims 1 to 6, wherein, Further comprising: A first diode and / or a second diode. One end of the tenth resistor is connected with one end of the sixth capacitor, and a connection point serves as one end of the low-pass filter circuit. The other end of the tenth resistor serves as the other end of the low-pass filter circuit.

10. The temperature sampling circuit of any one of claims 1 to 6, wherein, The other end of the sixth capacitor is grounded. Further comprising: A first diode and / or a second diode. One end of the tenth resistor is connected with one end of the sixth capacitor, and a connection point serves as one end of the low-pass filter circuit. The other end of the tenth resistor serves as the other end of the low-pass filter circuit. The other end of the sixth capacitor is grounded. Further comprising: A first diode and / or a second diode. One end of the tenth resistor is connected with one end of the sixth capacitor, and a connection point serves as one end of the low-pass filter circuit. The other end of the tenth resistor serves as the other end of the low-pass filter circuit. The other end of the sixth capacitor is grounded. Further comprising: A first diode and / or a second diode. One end of the tenth resistor is connected with one end of the sixth capacitor, and a connection point serves as one end of the low-pass filter circuit. The other end of the tenth resistor serves as the other end of the low-pass filter circuit. The other end of the sixth capacitor is grounded. Further comprising: A first diode and / or a second diode. One end of the tenth resistor is connected with one end of the sixth capacitor, and a connection point serves as one end of the low-pass filter circuit. The other end of the tenth resistor serves as the other end of the low-pass filter circuit. The other end of the sixth capacitor is grounded. Further comprising: A first diode and / or a second diode. One end of the tenth resistor is connected with one

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