A chip temperature sensor circuit and an audio power amplifier

Abstract

This application provides a chip temperature sensor circuit and an audio power amplifier. The digital logic control unit in the circuit is used to output a first control signal; the first control signal is used to control the on / off state of the corresponding current source adjustment circuit in the temperature sampling unit; the temperature sampling unit is used to output a first sampling voltage and a second sampling voltage; the buffer comparison amplification unit is used to obtain the temperature sampling voltage based on the first sampling voltage and the second sampling voltage; the digital logic control unit is used to perform differential processing on the digital voltage signals corresponding to the temperature sampling voltage under different states of the temperature sampling unit to eliminate the slope deviation of the chip temperature sensor circuit and obtain the chip temperature; that is, the chip temperature sensor current provided by this application cancels the problem of inaccurate temperature detection caused by process deviation, and can also avoid the problem that the single-point calibration method can only calibrate the DC deviation and cannot calibrate the slope deviation of the temperature sensor itself, resulting in poor calibration accuracy.

Description

Technical Field

[0001] This invention relates to the field of semiconductor integrated circuit technology, specifically to a chip temperature sensor circuit and an audio power amplifier. Background Technology

[0002] The main function of the temperature sensor circuit is to sense changes in the ambient temperature and output a corresponding voltage change, which is then decoded by the digital-to-analog converter at the back end to obtain the temperature reading.

[0003] The curve of the detection voltage of the temperature sensor circuit changing with temperature is shown below. Figure 1 As shown. Ideally, voltage and temperature have a linear relationship, which can be expressed as V = k0T + a0; where V represents the detection voltage, T represents the ambient temperature, and k... O Let a represent the slope and a0 represent the intercept. However, in manufacturing, the curve of the detection voltage of the temperature sensor circuit changing with temperature may deviate, becoming V = k n T+a n ; where a represents the DC deviation of the vertical translation of the two curves. n -a0, slope deviation is k n -k0.

[0004] In mass production testing, chips are typically calibrated based on the temperature of the test environment, i.e., a single-point calibration method is used to calibrate deviations. Although this single-point calibration method is low-cost and widely used, it can only calibrate DC deviations and cannot calibrate the slope deviation of the temperature sensor circuit itself, resulting in poor calibration accuracy. Summary of the Invention

[0005] In response to this, this application provides a chip temperature sensor circuit and an audio power amplifier to solve the problem that existing single-point calibration methods can only calibrate DC deviations and cannot calibrate the slope deviation of the temperature sensor circuit itself, resulting in poor calibration accuracy.

[0006] To achieve the above objectives, the embodiments of the present invention provide the following technical solutions:

[0007] The first aspect of this invention discloses a chip temperature sensor circuit, comprising: a temperature sampling unit, a buffer comparison and amplification unit, and a digital logic control unit; wherein:

[0008] The digital logic control unit is used to output a first control signal; the first control signal is used to control the on / off state of the corresponding current source adjustment circuit in the temperature sampling unit;

[0009] The temperature sampling unit is used to output a first sampling voltage and a second sampling voltage;

[0010] The buffer comparison amplification unit is used to obtain the temperature sampling voltage based on the first sampling voltage and the second sampling voltage;

[0011] The digital logic control unit is used to perform subtraction processing on the digital voltage signals corresponding to the temperature sampling voltage under different states of the temperature sampling unit to eliminate the slope deviation of the chip temperature sensor circuit and obtain the temperature of the chip; wherein, the digital voltage signal is obtained by converting the temperature sampling voltage by a digital-to-analog conversion circuit.

[0012] Optionally, in the above-described chip temperature sensor circuit, the digital logic control unit is further configured to: average the temperatures of the same chip obtained multiple times consecutively, and use the average result as the temperature of the chip.

[0013] Optionally, in the above-described chip temperature sensor circuit, the temperature sampling unit includes: a first current source, a first switching transistor, a second current source, a second switching transistor, and at least one of the current source adjustment circuits;

[0014] In this configuration, one end of the first current source and one end of the second current source both receive the supply voltage;

[0015] The other end of the first current source is connected to the first end of the first switching transistor, and the connection point serves as the first output terminal of the temperature sampling unit, outputting the first sampling voltage; the control terminal of the first switching transistor is connected to the second end of the first switching transistor and grounded.

[0016] The other end of the second current source is connected to the first end of the second switching transistor, and the connection point serves as the second output terminal of the temperature sampling unit, outputting the second sampling voltage.

[0017] Optionally, in the above-described chip temperature sensor circuit, the number of current source adjustment circuits is 1, and the current source adjustment circuit is connected in parallel with the first current source, including: N current source branches; N is a positive integer;

[0018] Each current source branch includes: a third current source and a first branch switch; the third current source is connected in series with the first branch switch, and the on / off state of the first branch switch is controlled by the first control signal.

[0019] Optionally, in the above-described chip temperature sensor circuit, the number of current source adjustment circuits is 1, and the current source adjustment circuit is connected in parallel with the second current source, including: N current source branches; N is a positive integer;

[0020] Each current source branch includes: a third current source and a first branch switch; the third current source is connected in series with the first branch switch, and the on / off state of the first branch switch is controlled by the first control signal.

[0021] Optionally, in the above-mentioned chip temperature sensor circuit, the number of current source adjustment circuits is 2, one of the current source adjustment circuits is connected in parallel with the first current source, and the other of the current source adjustment circuits is connected in parallel with the second current source;

[0022] The current source adjustment circuit includes: N current source branches; N is a positive integer;

[0023] Each current source branch includes: a third current source and a first branch switch; the third current source is connected in series with the first branch switch, and the on / off state of the first branch switch is controlled by the first control signal.

[0024] Optionally, the above-mentioned chip temperature sensor circuit further includes: a proportional adjustment circuit, wherein the proportional adjustment circuit is connected in parallel with the first switching transistor and / or the second switching transistor, and the proportional adjustment circuit includes: M proportional branches; M is a positive integer;

[0025] Each of the aforementioned proportional branches includes: a third switch and a second branch switch; the third switch and the second branch switch are connected in series;

[0026] The digital logic control unit is also used to output a second control signal, which is used to control the on / off state of the second branch switch in the proportional adjustment circuit.

[0027] Optionally, in the chip temperature sensor circuit described above, the buffer comparison amplification unit includes: a first operational amplifier, a second operational amplifier, a third operational amplifier, a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, and a first capacitor;

[0028] Wherein, the non-inverting input terminal of the first operational amplifier serves as the first input terminal of the buffered comparator amplification unit, receiving the first sampled voltage; the output terminal of the first operational amplifier is connected to the inverting input terminal of the first operational amplifier and one end of the first resistor respectively; the other end of the first resistor is connected to the second resistor and the non-inverting input terminal of the third operational amplifier respectively; the other end of the second resistor is grounded;

[0029] The non-inverting input of the second operational amplifier serves as the second input of the buffered comparator amplification unit, receiving the second sampled voltage; the output of the second operational amplifier is connected to the inverting input of the second operational amplifier and one end of the third resistor; the other end of the third resistor is connected to the inverting input of the third operational amplifier and one end of the fourth resistor.

[0030] The output terminal of the third operational amplifier is connected to the other end of the fourth resistor and one end of the fifth resistor, respectively; the other end of the fifth resistor is connected to one end of the first capacitor, and the connection point serves as the output terminal of the buffer comparison amplification unit, which outputs the temperature sampling voltage.

[0031] A second aspect of the present invention discloses an audio power amplifier, comprising: a chip temperature sensor circuit as described in any of the claims of the first aspect.

[0032] Optionally, the aforementioned audio power amplifier further includes a processor, which is connected to the output of the digital-to-analog conversion circuit in the chip temperature sensor circuit;

[0033] The processor is used to obtain the temperature of the chip based on the digital voltage signal output by the digital-to-analog conversion circuit and the correspondence between the digital voltage signal and the temperature.

[0034] The chip temperature sensor circuit provided by this invention includes: a temperature sampling unit, a buffer comparison and amplification unit, a digital-to-analog conversion circuit, and a digital logic control unit; wherein: the digital logic control unit is used to output a first control signal; the first control signal is used to control the on / off state of the corresponding current source adjustment circuit in the temperature sampling unit; the temperature sampling unit is used to output a first sampling voltage and a second sampling voltage; the buffer comparison and amplification unit is used to obtain a temperature sampling voltage based on the first sampling voltage and the second sampling voltage; the digital logic control unit is used to perform subtraction processing on the digital voltage signals corresponding to the temperature sampling voltage in different states of the temperature sampling unit to eliminate the slope deviation of the chip temperature sensor circuit and obtain the chip temperature; wherein, the digital voltage signal is obtained by converting the temperature sampling voltage by the digital-to-analog conversion circuit; that is, this application uses the digital logic control unit to control the on / off state of the corresponding current source adjustment circuit in the temperature sampling unit to obtain the temperature sampling voltage corresponding to different states, and performs subtraction processing on the digital voltage signals corresponding to the temperature sampling voltage in different states to obtain the chip temperature, thus offsetting the problem of inaccurate temperature detection caused by process deviation, and also avoiding the problem that single-point calibration can only calibrate DC deviation and cannot calibrate the slope deviation of the temperature sensor itself, resulting in poor calibration accuracy. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0036] Figure 1 A graph showing the voltage change with temperature in a temperature sensor circuit provided in this application embodiment;

[0037] Figure 2 This application provides an example of a conventional chip temperature sensor circuit.

[0038] Figure 3 This is a schematic diagram of the structure of a chip temperature sensor circuit provided in an embodiment of this application;

[0039] Figures 4 to 7 Circuit diagrams of the four chip temperature sensor circuits provided in this application;

[0040] Figure 8 The MC curve of a conventional chip temperature sensor circuit provided in this application;

[0041] Figure 9 A schematic diagram of the deviation simulation of an existing chip temperature sensor circuit provided in this application;

[0042] Figure 10 This is a schematic diagram of the deviation simulation of a chip temperature sensor circuit provided in this application. Detailed Implementation

[0043] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0044] First, it needs to be stated that, Figure 2 The existing scheme shown assumes all op-amp offsets, such as the offset V of operational amplifier A1 in the figure. OS1 Offset V of operational amplifier A2 OS2 Offset V of operational amplifier in I5 OS3 All of them are temperature-independent DC current, meaning they can be calibrated at a single point. The inventors discovered that as technology advances, the operational amplifier's offset will become linearly related to temperature and cannot be ignored.

[0045] Assumption Figure 2 If the ratio between resistors R1 and R4 is 12, then considering the imbalance, we have: V OUT =12×(V) BE2 -V BE1 -13V OS3 +12V OS2 -12V OS1 Let the temperature coefficient of the misalignment be K. O Then -13V OS3 +12V OS2 -12V OS1 =K O T, therefore V OUT = (23.2+K) O V T It can be seen that the slope has deviated, and this deviation can no longer be eliminated by single-point calibration.

[0046] Based on the above, this application provides a chip temperature sensor circuit to solve the problem that the existing single-point calibration method can only calibrate DC deviation and cannot calibrate the slope deviation of the temperature sensor circuit itself, resulting in poor calibration accuracy.

[0047] Please see Figure 3 The temperature sensor current of this chip may include: a temperature sampling unit 101, a buffer comparison and amplification unit 102, a digital-to-analog conversion circuit 104, and a digital logic control unit 103. Wherein:

[0048] The digital logic control unit 103 is used to output a first control signal; the first control signal is used to control the on / off state of the corresponding current source adjustment circuit 1011 in the temperature sampling unit 101.

[0049] The temperature sampling unit 101 is used to output the first sampling voltage VBE1 and the second sampling voltage VBE2.

[0050] In practical applications, such as Figure 4 As shown, the temperature sampling unit 101 may include: a first current source cI, a first switching transistor BJT1, a second current source bI, a second switching transistor BJT2, and at least one current source adjustment circuit 1011.

[0051] In this system, one end of the first current source cI and one end of the second current source bI both receive the supply voltage.

[0052] In practical applications, the specific type of power supply voltage can be determined according to the specific application environment and user needs. This application does not make specific limitations, and all such voltages fall within the protection scope of this application.

[0053] The other end of the first current source cI is connected to the first end of the first switching transistor BJT1, and the connection point serves as the first output terminal of the temperature sampling unit 101, outputting the first sampling voltage VBE1; the control terminal of the first switching transistor BJT1 is connected to the second end of the first switching transistor BJT1 and grounded.

[0054] The other end of the second current source bI is connected to the first end of the second switching transistor BJT2. The connection point serves as the second output terminal of the temperature sampling unit 101, outputting the second sampling voltage VBE2.

[0055] Specifically, such as Figure 5 As shown, if the number of current source adjustment circuits 1011 is 1, the current source adjustment circuit 1011 can be connected in parallel with the first current source cI, including: N current source branches ( Figure 5 (Taking only one current source branch as an example); N is a positive integer.

[0056] Each current source branch includes: a third current source aI and a first branch switch K1; the third current source aI is connected in series with the first branch switch K1, and the opening and closing of the first branch switch K1 is controlled by a first control signal.

[0057] Of course, it can also be like Figure 4 As shown, if the number of current source adjustment circuits 1011 is 1, the current source adjustment circuit 1011 can also be connected in parallel with the second current source bI, including: N current source branches ( Figure 4 (Taking only one current source branch as an example); N is a positive integer.

[0058] Each current source branch includes: a third current source aI and a first branch switch K1; the third current source aI is connected in series with the first branch switch K1, and the opening and closing of the first branch switch K1 is controlled by a first control signal.

[0059] In practical applications, such as Figure 6 As shown, if the number of current source adjustment circuits 1011 is 2, one current source adjustment circuit 1011 is connected in parallel with the first current source cI, and the other current source adjustment circuit 1011 is connected in parallel with the second current source bI.

[0060] The current source adjustment circuit 1011 includes: N current source branches ( Figure 6 (Taking only one current source branch as an example); N is a positive integer.

[0061] Each current source branch includes: a third current source aI and a first branch switch K1; the third current source aI is connected in series with the first branch switch K1, and the opening and closing of the first branch switch K1 is controlled by a first control signal.

[0062] It is understood that the number and location of the current source adjustment circuit 1011 can be set according to the specific application environment and user needs. Regardless of which current source adjustment circuit 1011 is set on any current source in the temperature sampling circuit, it will not affect the implementation of this application.

[0063] In practical applications, the first current source cI, the second current source bI, and the third current source aI are generally selected from the same type of current source. For example, they can all be digitally controlled current sources. Of course, they can also be determined according to the specific application environment and user needs. This application does not make specific limitations, and all of them fall within the protection scope of this application.

[0064] The buffer comparison amplification unit 102 is used to obtain the temperature sampling voltage based on the first sampling voltage VBE1 and the second sampling voltage VBE2.

[0065] In practical applications, such as Figures 4 to 7 As shown, the buffer comparison amplification unit 102 may include: a first operational amplifier A1, a second operational amplifier A2, a third operational amplifier A3, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, and a first capacitor C1.

[0066] In this configuration, the non-inverting input of the first operational amplifier A1 serves as the first input of the buffered comparator amplification unit 102, receiving the first sampling voltage VBE1; the output of the first operational amplifier A1 is connected to the inverting input of the first operational amplifier A1 and one end of the first resistor R1; the other end of the first resistor R1 is connected to the second resistor R2 and the non-inverting input of the third operational amplifier A3; and the other end of the second resistor R2 is grounded.

[0067] The non-inverting input of the second operational amplifier A2 serves as the second input of the buffered comparator amplifier unit 102, receiving the second sampling voltage VBE2; the output of the second operational amplifier A2 is connected to the inverting input of the second operational amplifier A2 and one end of the third resistor R3; the other end of the third resistor R3 is connected to the inverting input of the third operational amplifier A3 and one end of the fourth resistor R4.

[0068] The output of the third operational amplifier A3 is connected to the other end of the fourth resistor R4 and one end of the fifth resistor R5, respectively; the other end of the fifth resistor R5 is connected to one end of the first capacitor C1, and the connection point serves as the output of the buffered comparison amplification unit 102, which outputs the temperature sampling voltage.

[0069] The digital logic control unit 103 is used to perform subtraction processing on the digital voltage signals corresponding to the temperature sampling voltage of the temperature sampling unit 101 under different states to eliminate the slope deviation of the chip temperature sensor circuit and obtain the chip temperature.

[0070] The digital voltage signal is obtained by converting the temperature sampling voltage into a digital-to-analog converter circuit 104. In other words, the digital-to-analog converter circuit 104 can be set in the front stage of the digital logic control unit 103 to convert the temperature sampling voltage from an analog voltage signal into a digital voltage signal.

[0071] In practical applications, the digital logic control unit 103 can perform subtraction processing on the digital voltage signal corresponding to the temperature sampling voltage when the current source adjustment circuit 1011 in the temperature sampling unit 101 is in the on state and the digital voltage signal corresponding to the temperature sampling voltage when the current adjustment circuit is in the short-circuit state to eliminate the slope deviation of the chip temperature sensor circuit and obtain the chip temperature.

[0072] It should be noted that by converting the temperature sampling voltage from an analog voltage signal to a digital voltage through the digital-to-analog converter circuit 104, the computational complexity of the digital logic control unit 103 can be reduced.

[0073] It should also be noted that the specific structure of the digital-to-analog conversion circuit 104 can be found in the prior art, and will not be repeated here, as they all fall within the protection scope of this application.

[0074] It should be noted that the digital logic control unit 103 can be a DSP (Digital Signal Processing); of course, it is not limited to this, and can also be other devices with logic control. This application does not specifically limit them, and they all fall within the protection scope of this application.

[0075] Based on the above, this embodiment provides a chip temperature sensor circuit. The digital logic control unit 103 controls the on / off state of the corresponding current source adjustment circuit 1011 in the temperature sampling unit 101 to obtain the temperature sampling voltage corresponding to different states. The circuit performs subtraction processing on the digital voltage signals corresponding to the temperature sampling voltages under different states to eliminate the slope deviation of the chip temperature sensor circuit and obtain the chip temperature. This offsets the problem of inaccurate temperature detection caused by process deviations and avoids the problem that single-point calibration can only calibrate DC deviations and cannot calibrate the slope deviation of the temperature sensor itself, resulting in poor calibration accuracy.

[0076] It is worth noting that, Figure 2 The existing solution shown also obtains a voltage that changes linearly with temperature by subtracting the first sampling voltage VBE1 and the second sampling voltage VBE2. Then, an ADC converts the analog voltage signal into a digital voltage signal to obtain the temperature value. However, while existing technology eliminates the offset of A2 and A3 by controlling the switching of K1-K8, it cannot eliminate the offset of the op-amp in I5. This op-amp offset introduces K... OThe slope deviation is eliminated because the present application can control the on / off state of the corresponding current source adjustment circuit 1011 in the temperature sampling unit 101 through the digital logic control unit 103 to obtain the temperature sampling voltage corresponding to different states, and perform subtraction processing on the digital voltage signal corresponding to the temperature sampling voltage in different states to obtain the chip temperature. Furthermore, the prior art also introduces 8 switches, which increases the complexity of analog circuit design. In addition, the switching will also introduce additional deviations such as charge injection and coupling. The present application only needs to set the current source adjustment circuit 1011 and control the on / off state of the current source adjustment current through the digital logic control unit 103, which reduces the complexity of analog circuit design and reduces the additional deviations caused by charge injection and coupling.

[0077] It is also worth noting that although existing methods can provide chip temperature detection accuracy through two-point calibration, that is, in addition to room temperature testing on the production line, a high temperature test is performed again, and the slope of the detected temperature change with room temperature is fitted by sampling two points, thereby calibrating both the slope and DC deviation, this calibration method is difficult to implement and costly, and is not suitable for mass-produced industrial chips. The method provided in this application can also achieve high-precision temperature detection through single-point calibration, which is more suitable for application in mass-produced industrial chips.

[0078] Optionally, in another embodiment provided in this application, the digital logic control unit 103 is further configured to: average the temperature of the same chip obtained multiple times consecutively, and use the average result as the temperature of the chip.

[0079] In practical applications, to improve the accuracy of the final obtained chip temperature, the temperature of the same chip can be averaged by taking multiple measurements consecutively, and then the average result can be used as the chip temperature.

[0080] Of course, other data processing methods can also be used to process the temperature of the same chip obtained multiple times in succession to improve the accuracy of the final obtained chip temperature. This application does not specifically limit the data processing methods, and all of them are within the protection scope of this application.

[0081] Alternatively, in another embodiment provided in this application, please refer to Figure 7 (exist Figure 6 Based on the above, the chip temperature sensor current also includes: a proportional adjustment circuit 1012, which is connected in parallel with the first switching transistor BJT1 and / or the second switching transistor BJT2. The proportional adjustment circuit 1012 includes: M proportional branches ( Figure 7 (Taking only one proportional branch as an example); M is a positive integer.

[0082] Each proportional branch includes: a third switch BJT3 and a second branch switch K2; the third switch BJT3 and the second branch switch K2 are connected in series.

[0083] The digital logic control unit 103 is also used to output a second control signal, which is used to control the on / off state of the second branch switch K2 in the proportional adjustment circuit 1012.

[0084] In practical applications, the ratio of the current can be adjusted to regulate the ratio of the corresponding switching transistors in the chip temperature sensor circuit, thereby achieving the purpose of secondary calibration.

[0085] Specifically, the control timing of the first control signal and the second control signal output by the digital logic control unit 103 is the same. In other words, when the first control signal controls the first branch switch K1 to open, the second control switch signal also controls the second branch switch K2 to be in the open state; when the first control switch controls the first branch switch K1 to close, the second control signal controls the second branch switch K2 to be in the closed state.

[0086] Of course, the control timing of the first control signal and the second control signal output by the digital logic control unit 103 can also be different, depending on the specific application environment and user needs. This application does not make specific limitations, and all of them fall within the protection scope of this application.

[0087] It should be noted that, Figure 7 Taking the parallel connection of the proportional adjustment circuit 1012 and the second switching transistor BJT2 as an example, in actual applications, the parallel connection of the proportional adjustment circuit 1012 and the first switching transistor BJT1 is the same as described above. They can be referred to each other, so they will not be described in detail again. All of them are within the protection scope of this application.

[0088] It should also be noted that in practical applications, the ratio between the first switching transistor BJT1 and the second switching transistor BJT2 is generally 1:1; of course, it is not limited to this, and can be determined according to the specific application environment and user, all of which are within the scope of protection of this application.

[0089] Based on the chip temperature sensor circuit provided in the above embodiments, corresponding embodiments are provided for the content of the above embodiments. For ease of understanding, it is assumed that the chip temperature sensor circuit structure is as follows. Figure 4 As shown, the ratio between the first current source cI, the second current source bI, and the third current source aI is 1:2:8, and the ratio of the third resistor R3 to the fourth resistor R4 is 12. The specific implementation process of this application is as follows:

[0090] First, close the first branch switch K1 and measure the temperature sampling voltage Vout1 to obtain:

[0091] V OUT1 =12VT log(10)-13V OS2 +12V OS2 -12V OS1 =(23.02+k) o V T ;in, Where is Boltzmann's constant, q is the electron charge, and V is... OS1 V represents the offset voltage of the first operational amplifier A1. OS2 V represents the offset voltage of the second operational amplifier A2. OS3 This represents the offset voltage of the third operational amplifier A3.

[0092] Then, by opening the first branch switch K1 and measuring the temperature sampling voltage Vout1, we can obtain:

[0093] V OUT2 =12V T log(2)-13V OS2 +12V OS2 -12V OS1 = (8.32+k) o V T .

[0094] The digital logic control unit 103 performs a difference operation on the voltage after digital-to-analog conversion to obtain:

[0095] V OUT =V OUT2 -V OUT1 =12V T (log(10)-log(2))=14.7V T .

[0096] From the above formula, it can be seen that subtracting the two outputs yields a result that is not affected by K. O The voltage curve showing the effect of temperature has a fixed slope.

[0097] Furthermore, taking the simulation results of a certain process as an example, the MC curve of its output voltage versus temperature at 100 points after designing with the existing scheme is as follows: Figure 8 The single-point calibration method can simulate the temperature detection deviation of the chip after production line calibration. Existing solutions exhibit deviations such as... Figure 9 As shown. From Figure 9 The simulation results show that within the detection range of -40℃ to 150℃, the existing solution has a detection deviation exceeding 12℃. The deviation simulation results of this invention are as follows: Figure 10 As shown, after MC simulations with the same number of points, the temperature deviation was reduced to within 5℃.

[0098] Optionally, another embodiment of this application also provides an audio power amplifier, including: a chip temperature sensor circuit as described in any of the above embodiments.

[0099] In practical applications, the audio power amplifier may also include a processor, which is connected to the output of the digital-to-analog conversion circuit in the chip temperature sensor circuit.

[0100] The processor is used to obtain the chip temperature based on the digital voltage signal output by the digital-to-analog converter circuit and the correspondence between the digital voltage signal and temperature.

[0101] It should be noted that relevant instructions regarding the chip temperature sensor circuit can be found at [link to relevant documentation]. Figures 3 to 10 The corresponding embodiments will not be described in detail here; relevant descriptions of audio power amplifiers can also be found in the prior art, and will not be described in detail here.

[0102] The features described in the various embodiments of this specification can be substituted for or combined with each other. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, for system or system embodiments, since they are basically similar to method embodiments, the description is relatively simple; relevant parts can be referred to the descriptions in the method embodiments. The systems and system embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without creative effort.

[0103] Those skilled in the art will further recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0104] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0105] It should also be noted that, in this document, relational 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 these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

Claims

1. A chip temperature sensor circuit, characterized by, The chip temperature sensor circuit comprises a temperature sampling unit, a buffer comparison amplification unit, a digital analog conversion circuit and a digital logic control unit, wherein: The digital logic control unit is configured to output a first control signal, and the first control signal is configured to control the on-off of a corresponding current source adjustment circuit in the temperature sampling unit. The temperature sampling unit is configured to output a first sampling voltage and a second sampling voltage. The buffer comparison amplification unit is configured to obtain a temperature sampling voltage according to the first sampling voltage and the second sampling voltage. The digital logic control unit is configured to perform difference processing on digital voltage signals corresponding to the temperature sampling voltage when the temperature sampling unit is in different states respectively, so as to eliminate the slope deviation of the chip temperature sensor circuit and obtain the temperature of the chip, wherein the digital voltage signals are obtained by converting the temperature sampling voltage by the digital analog conversion circuit. The temperature sampling unit comprises a first current source, a first switch tube, a second current source, a second switch tube and at least one current source adjustment circuit, wherein one end of the first current source and one end of the second current source both receive a supply voltage; the other end of the first current source is connected with the first end of the first switch tube, and the connection point serves as a first output end of the temperature sampling unit and outputs the first sampling voltage; the control end of the first switch tube is connected with the second end of the first switch tube and grounded; the other end of the second current source is connected with the first end of the second switch tube, and the connection point serves as a second output end of the temperature sampling unit and outputs the second sampling voltage. At least one current source adjustment circuit is connected in parallel with the first current source and / or at least one current source adjustment circuit is connected in parallel with the second current source. The digital logic control unit is further configured to average the temperatures of the same chip obtained continuously for multiple times, and take the average result as the temperature of the chip.

2. The chip temperature sensor circuit of claim 1, wherein, The number of current source adjustment circuits is 1, and the current source adjustment circuit is connected in parallel with the first current source.

3. The chip temperature sensor circuit of claim 1, wherein, The number of current source adjustment circuits is 1, and the current source adjustment circuit is connected in parallel with the second current source.

4. The chip temperature sensor circuit of claim 1, wherein, The number of current source adjustment circuits is 2, one current source adjustment circuit is connected in parallel with the first current source, and the other current source adjustment circuit is connected in parallel with the second current source.

5. The chip temperature sensor circuit of claim 1, wherein, Further comprising a proportional adjustment circuit connected in parallel with the first switch tube and / or the second switch tube, and the proportional adjustment circuit comprises M proportional branches, wherein M is a positive integer.

6. The chip temperature sensor circuit of claim 4, wherein, Each proportional branch comprises a third switch tube and a second branch switch, and the third switch tube is connected in series with the second branch switch. The digital logic control unit is further configured to output a second control signal, and the second control signal is configured to control the on-off of the second branch switch in the proportional adjustment circuit. The buffer comparison amplification unit comprises a first operational amplifier, a second operational amplifier, a third operational amplifier, a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor and a first capacitor.

7. The chip temperature sensor circuit of any of claims 1-6, wherein, ​ The noninverting input terminal of the first operational amplifier is connected to the first input terminal of the buffer comparison amplification unit and receives the first sampling voltage; the output terminal of the first operational amplifier is connected to the inverting input terminal of the first operational amplifier and one end of the first resistor; the other end of the first resistor is connected to the second resistor and the noninverting input terminal of the third operational amplifier; the other end of the second resistor is grounded; The noninverting input terminal of the second operational amplifier is connected to the second input terminal of the buffer comparison amplification unit and receives the second sampling voltage; the output terminal of the second operational amplifier is connected to the inverting input terminal of the second operational amplifier and one end of the third resistor; the other end of the third resistor is connected to the inverting input terminal of the third operational amplifier and one end of the fourth resistor; The output terminal of the third operational amplifier is connected to the other end of the fourth resistor and one end of the fifth resistor; the other end of the fifth resistor is connected to one end of the first capacitor, and the connection point is the output terminal of the buffer comparison amplification unit and outputs the temperature sampling voltage.

8. An audio power amplifier characterized by, The chip temperature sensor circuit comprises: The chip temperature sensor circuit according to any one of claims 1-7.

9. The audio power amplifier of claim 8, wherein, Further comprising: A processor connected to the output terminal of the digital-to-analog conversion circuit in the chip temperature sensor circuit; The processor is used to obtain the temperature of the chip according to the digital voltage signal output by the digital-to-analog conversion circuit and the corresponding relationship between the digital voltage signal and the temperature.

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