Feedback circuit, analog-to-digital conversion circuit, temperature measurement circuit, chip, and electronic device

Abstract

The present application provides a feedback circuit, an analog-to-digital conversion circuit, a temperature measurement circuit, a chip, and an electronic device. The feedback circuit comprises: at least one digital gain modulation module, each digital gain modulation module being used for outputting a second digital signal on the basis of a first digital signal within each measurement period; and at least one charge feedback module, each charge feedback module being used for outputting a charge signal on the basis of at least one second digital signal and at least one preset reference voltage within each measurement period. In the present application, gain calibration of a target circuit can be achieved by adjusting a preset coefficient of a digital gain unit in a feedback loop, thereby ensuring the consistency between an input voltage signal and an output digital signal of the target circuit.

Description

Feedback circuit, analog-to-digital conversion circuit, temperature measurement circuit, chip and electronic device

[0001] The present application claims priority to the Chinese patent application No. 202410849044.5, filed on June 27, 2024, and entitled "Feedback circuit, analog-to-digital conversion circuit, temperature measurement circuit, chip and electronic device", the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0002] The present application relates to, but is not limited to, the technical field of integrated circuits, and in particular to a feedback circuit, an analog-to-digital conversion circuit, a temperature measurement circuit, a chip and an electronic device. BACKGROUND

[0003] At present, a Sigma-Delta modulator (SDM) is a high-precision analog-to-digital converter with oversampling characteristics, which is often used for high-precision measurement of low-frequency voltage signals. In the related art, the Sigma-Delta modulator mainly includes an integrator for integrating input charge signals corresponding to input voltage signals and feedback charge signals corresponding to reference voltage signals, a comparator for comparing a reference voltage with an output result of the integrator, and a feedback circuit for generating the feedback charge signals corresponding to the reference voltage signals.

[0004] During the operation of the Sigma-Delta modulator, the feedback circuit performs negative feedback according to the output result of the comparator, so that the output result of the integrator approaches or equals 0 in multiple cycles. Finally, after the integrator integrates the input charge signals corresponding to the input voltage signals and the feedback charge signals corresponding to the reference voltage signals for multiple times, the size of the input voltage signal is quantized by the difference between the number of feedback positive charge signals and the number of feedback negative charge signals and the size of the reference voltage signal. However, there is usually an error between the digital signal output by the Sigma-Delta modulator and the input voltage signal, so it is necessary to calibrate the gain of the Sigma-Delta modulator to ensure the consistency of the input voltage signal and the output digital signal. TECHNICAL SOLUTION

[0005] In view of the above problems, the present application provides a feedback circuit, an analog-to-digital conversion circuit, a temperature measurement circuit, a chip and an electronic device to solve the above technical problems.

[0006] In a first aspect, the present application provides a feedback circuit, which is configured to feed back charge signals to an input end of a target circuit according to a first digital signal output from an output end of the target circuit in each measurement period. The feedback circuit comprises:

[0007] at least one digital gain modulation module, each digital gain modulation module being configured to output a second digital signal according to the first digital signal in each measurement period.

[0008] at least one charge feedback module, each charge feedback module being configured to output a charge signal according to the at least one second digital signal and at least one preset reference voltage in each measurement period.

[0009] Each digital gain modulation module comprises a digital gain unit configured to amplify / reduce the first digital signal by a preset coefficient.

[0010] In a second aspect, the embodiments of the present application further provide an analog-to-digital conversion circuit comprising the feedback circuit.

[0011] In a third aspect, the embodiments of the present application further provide a temperature measurement circuit comprising the chip or the feedback circuit.

[0012] In a fourth aspect, the embodiments of the present application further provide a chip comprising the analog-to-digital conversion circuit or the temperature measurement circuit.

[0013] In a fifth aspect, the embodiments of the present application further provide an electronic device comprising the chip.

[0014] The feedback circuit feeds back a charge signal to the input end of the target circuit according to the first digital signal output by the output end of the target circuit in each measurement period. Since each digital gain modulation module of the feedback circuit comprises a digital gain unit configured to amplify / reduce the first digital signal by a preset coefficient, the preset coefficient of the digital gain unit can be adjusted in the feedback link, so that the gain calibration of the target circuit can be realized, and the consistency between the input voltage signal and the output digital signal of the target circuit can be ensured.

[0015] These and other aspects of the present application will become more apparent from the following description. BRIEF DESCRIPTION OF DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced. 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.

[0017] FIG. 1 shows a schematic diagram of a Sigma-Delta modulator in the related art.

[0018] FIG. 2 shows a schematic diagram of a feedback circuit and a target circuit in the embodiments of the present application.

[0019] FIG. 3 shows another schematic diagram of a feedback circuit and a target circuit in the embodiments of the present application.

[0020] Figure 4 shows another schematic diagram of the feedback circuit and the target circuit in the embodiment of the present application.

[0021] Figure 5 shows a schematic diagram of the target circuit in the embodiment of the present application.

[0022] Figure 6 shows another schematic diagram of the target circuit in the embodiment of the present application.

[0023] Figure 7 shows another schematic diagram of the feedback circuit and the target circuit in the embodiment of the present application.

[0024] Figure 8 shows another schematic diagram of the feedback circuit and the target circuit in the embodiment of the present application.

[0025] Figure 9 shows another schematic diagram of the feedback circuit and the target circuit in the embodiment of the present application.

[0026] Figure 10 shows another schematic diagram of the feedback circuit and the target circuit in the embodiment of the present application.

[0027] Figure 11 shows another schematic diagram of the feedback circuit and the target circuit in the embodiment of the present application.

[0028] Figure 12 shows another schematic diagram of the feedback circuit and the target circuit in the embodiment of the present application.

[0029] Figure 13 shows another schematic diagram of the feedback circuit and the target circuit in the embodiment of the present application.

[0030] Figure 14 shows another schematic diagram of the charge feedback module in the embodiment of the present application.

[0031] Figure 15 shows another schematic diagram of the feedback circuit and the target circuit in the embodiment of the present application.

[0032] Figure 16 shows another schematic diagram of the feedback circuit and the target circuit in the embodiment of the present application.

[0033] Figure 17 shows another schematic diagram of the feedback circuit and the target circuit in the embodiment of the present application.

[0034] wherein, 100 feedback circuit, 110 digital gain modulation module, 111 digital gain unit, 112 digital integration unit, 113 digital quantization unit, 120 charge feedback module;

[0035] 200 target circuit, 210 input sampling module, 220 analog integration module, 230 analog quantization module;

[0036] first digital signal Dout, second digital signal D1-DN, charge signal Q1-QN, preset reference voltage V1-VN, preset coefficient K1-KN;

[0037] 1101 first digital gain modulation module, 1102 second digital gain modulation module, 1103 third digital gain modulation module, 1201 first charge feedback module, 1202 second charge feedback module, 1203 third charge feedback module; gain digital signal Dgain, integral digital signal Dint, preset digital signal DR.

[0038] Embodiments of the present application

[0039] Embodiments of the present application are described below in detail, examples of which are shown in the accompanying drawings, wherein the same or similar notations represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below are exemplary only, and are used only for explanation of the present application, and cannot be understood as a limitation of the present application.

[0040] In order to make the personnel in the technical field better understand the scheme of the present application, the technical scheme in the embodiments of the present application will be described clearly and completely below in combination with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0041] In the embodiments of the present application, it should be noted that, in this document, relationship terms such as first and second are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations.

[0042] Moreover, the term "include", "contain" or any other variant thereof is intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or equipment. Without more limitation, the element defined by the sentence "including a…" does not exclude the existence of other identical elements in the process, method, article or equipment including the element.

[0043] In the description of the embodiments of the present application, the words "example" or "for example" are used to mean example, illustration or description. Any embodiment or design scheme described as "example" or "for example" in the embodiments of the present application is not interpreted as more preferred or having more advantages than another embodiment or design scheme. The use of the words "example" or "for example" is intended to present the relative concept in a clear manner.

[0044] In addition, "multiple" in the embodiments of the present application refers to two or more, and therefore, "multiple" in the embodiments of the present application can also be understood as "at least two". "At least one" can be understood as one or more, for example, understood as one, two or more. For example, "including at least one" means including one, two or more, and does not limit which ones are included, for example, including at least one of A, B and C, and then the included can be A, B, C, A and B, A and C, B and C, or A and B and C.

[0045] It should be noted that "connection" in the embodiments of the present application can be understood as electrical connection, and the connection between two electrical elements can be direct or indirect connection between the two electrical elements. For example, A and B are connected, which can be direct connection between A and B, or indirect connection between A and B through one or more other electrical elements.

[0046] In the circuit structure provided by the embodiments of the present application, the nodes such as the first node and the second node are not actual components, but are convergence points of relevant couplings in a circuit diagram, that is, these nodes are nodes equivalent to convergence points of relevant couplings in a circuit diagram.

[0047] At present, the Sigma-Delta modulator is a high-precision analog-to-digital converter with oversampling characteristics, and is commonly used for high-precision measurement of low-frequency voltage signals. Referring to FIG. 1, FIG. 1 shows a schematic diagram of a Sigma-Delta modulator in the related art, wherein the Sigma-Delta modulator includes a sampling circuit that samples an input voltage signal Vin and outputs an input charge signal Vin×C, a feedback circuit that generates a feedback charge signal ±Vdac×C corresponding to a reference voltage signal Vdac, an integrator that integrates the input charge signal Vin×C and the feedback charge signal ±Vdac×C, and a comparator that compares a reference voltage VR with an output result of the integrator.

[0048] In each measurement period of the Sigma-Delta modulator, the output result of the comparator controls the positive and negative of the feedback charge signal Vdac×C, so that the output result of the integrator is always near the reference voltage VR in multiple measurement periods. For example, in a measurement period, when the output voltage of the integrator is greater than the reference voltage VR, the comparator controls the feedback circuit to output a feedback positive charge signal +Vdac×C in the next measurement period, so that the output voltage of the integrator decreases; on the contrary, in a measurement period, when the output voltage of the integrator is less than the reference voltage VR, the comparator controls the feedback circuit to output a feedback negative charge signal -Vdac×C in the next measurement period, so that the output voltage of the integrator increases.

[0049] Since the output result of the integrator is negligible near the reference voltage VR in multiple measurement periods, the input voltage signal Vin, the reference voltage signal Vdac, the number of times of the feedback positive charge signal +VdacxC, and the number of times of the feedback negative charge signal -VdacxC satisfy the following relationship: VinxCX1+X2)=(VdacxCX1)-(VdacxCX2)

[0050] where C is a unit capacitance, X1 is the number of times of the feedback positive charge signal +VdacxC, and X2 is the number of times of the feedback negative charge signal -VdacxC.

[0051] Therefore, the input voltage signal Vin can be calculated according to the following formula:

[0052] It can be seen that the code value (for example, 011100..1100) output by the comparator in multiple measurement periods represents the number of times of the feedback positive charge signal +VdacxC and the number of times of the feedback negative charge signal -VdacxC, and therefore, the digital signal corresponding to the input voltage signal Vin can be obtained according to the signal output by the comparator.

[0053] However, there is usually an error between the digital signal output by the Sigma-Delta modulator and the input voltage signal, for example, when the input voltage signal is 1V, the voltage value corresponding to the digital signal output by the Sigma-Delta modulator after conversion according to the above formula can be 0.9V, which leads to the problem that the input voltage signal does not correspond to the converted digital signal.

[0054] Therefore, the present application provides a feedback circuit 100, an analog-to-digital conversion circuit, a temperature measurement circuit, a chip, and an electronic device, which are described in detail below.

[0055] First, refer to FIG. 2, which shows a schematic diagram of the feedback circuit 100 and the target circuit 200 in an embodiment of the present application. The feedback circuit 100 includes at least one digital gain modulation module 110 and at least one charge feedback module 120. The feedback circuit 100 of the present application is used to feed back a charge signal to the input end of the target circuit 200 according to the first digital signal Dout output from the output end of the target circuit 200 in each measurement period, so as to facilitate the normal operation of the target circuit 200.

[0056] In some embodiments of the present application, the target circuit 200 can perform analog-to-digital conversion according to the feedback charge signal. For example, referring to FIG. 3, which shows another schematic diagram of the feedback circuit 100 and the target circuit 200 in an embodiment of the present application, the target circuit 200 includes an input sampling module 210, an analog integration module 220, and an analog quantization module 230. The input sampling module 210 can output an input charge signal VinxC according to an input voltage signal Vin, the analog integration module 220 can integrate the input charge signal VinxC and a feedback charge signal Q1 output by the feedback circuit 100, and the analog quantization module 230 can perform digital quantization on a voltage signal output by the analog integration module 220 and output a first digital signal Dout.

[0057] After the target circuit 200 goes through a plurality of measurement periods, the charge integration result of the analog integration module 220 approaches or equals to 0, and it can be known that the input charge signal VinxC and the feedback charge signal Q1 satisfy the following relationship: VinxCxN=Q0 Q0=D11xV1xC+D12xV1xC+D1nxV1xC

[0058] wherein D11, D12,..., and D1n are respectively the second digital signal D1 of the first measurement period, the second measurement period, and the Nth measurement period, Q0 is the total amount of the feedback charge signal Q1 output by the feedback circuit 100, N is the number of the plurality of measurement periods, and C is a unit capacitance.

[0059] According to the above formula, since the feedback charge signal Q1 is output by the feedback circuit 100 according to the first digital signal Dout output by the target circuit 200, all the first digital signals Dout output by the analog quantization module 230 in the plurality of measurement periods correspond to the input voltage Vin, and thus the conversion code value corresponding to the input voltage Vin can be obtained at the output end of the analog quantization module 230.

[0060] In some embodiments of the present application, the target circuit 200 can perform temperature measurement according to the feedback charge signal. For example, referring to FIG. 4, which shows another schematic diagram of the feedback circuit 100 and the target circuit 200 in an embodiment of the present application, the target circuit 200 includes an analog integration module 220 and an analog quantization module 230. The analog integration module 220 can integrate the feedback charge signal Q1 output by the feedback circuit 100 and a charge signal Qx having a temperature coefficient, and the analog quantization module 230 can perform digital quantization on a voltage signal Vout output by the analog integration module 220 and output a first digital signal Dout.

[0061] Similar to the process of analog-digital conversion of the voltage signal, the function of the target circuit 200 is actually to quantize the charge signal Qx with temperature coefficient by the feedback charge signal Q1. After a plurality of measurement periods, the charge integration result of the analog integration module 220 approaches or equals to 0, which indicates that the feedback charge signal Q1 and the charge signal Qx satisfy the following relationship: Qx x N = Q0

[0062] Similarly, since the feedback charge signal Q1 is output by the feedback circuit 100 according to the first digital signal Dout output by the target circuit 200, all the first digital signals Dout output by the analog quantization module 230 in a plurality of measurement periods correspond to the charge signal Qx, so that the conversion code value corresponding to the charge signal Qx can be obtained in the analog quantization module 230, and the ambient temperature value can be finally obtained according to the conversion code value.

[0063] For example, the charge signal Qx with temperature coefficient is generated by the voltage Vt with temperature coefficient, and the mapping relationship between the voltage Vt and the temperature is known, for example, when the temperature is 25℃, the voltage Vt is 2.5V, when the temperature is 26℃, the voltage Vt is 2.52V, and when the temperature is 27℃, the voltage Vt is 2.55V. If the voltage value corresponding to the conversion code value of the analog quantization module 230 is 2.55V, it indicates that the measured ambient temperature is 27℃.

[0064] As an exemplary embodiment of the target circuit, referring to FIG. 5, FIG. 5 shows a schematic diagram of the target circuit 200 in the embodiment of the present application. The input sampling module 210 includes switches S1, S2 and a capacitor C, the integration module includes switches S3, S4, an integration capacitor CH1 and an operational amplifier OP, and the analog quantization module 230 includes a comparator COMP.

[0065] In a measurement period, when the switches S1 and S3 are closed and the switches S2 and S4 are opened, the charge amount of the integration capacitor CH1 remains unchanged, the capacitor C is charged based on the input voltage signal Vin, and the charge amount charged by the capacitor C is Vin x C. When the switches S1 and S3 are opened and the switches S2 and S4 are closed, since one plate of the capacitor C is grounded, the capacitor C will release the charge, charge the input charge signal with the charge amount of Vin x C to the integration capacitor CH1, and make the integration module complete the integration of the charge signal, so as to change the voltage at the output end of the operational amplifier OP. After the comparator COMP compares the operational amplifier OP with the reference voltage Vref, the first digital signal Dout of the period can be finally obtained at the output end of the comparator COMP.

[0066] It can be understood that the above embodiment is exemplarily described by taking the single-bit first digital signal Dout output by the analog quantization module 230 as an example, but is not limited thereto. For example, referring to FIG. 6, which shows another schematic diagram of the target circuit 200 in the embodiment of the present application, the analog quantization module 230 includes a plurality of comparators COMP, and the inverting input terminals of each comparator are connected to reference voltages Vref1, Vref2,..., Vrefn of different sizes, so that the analog quantization module 230 outputs a multi-bit first digital signal Dout.

[0067] The digital gain modulation module 110 of the feedback circuit 100 is configured to output a second digital signal according to the first digital signal Dout in each measurement period. In some embodiments of the present application, the first digital signal Dout and the second digital signal can have the same number of bits, for example, the first digital signal Dout and the second digital signal are both N-bit digital signals, and N is an integer greater than or equal to 1. In some embodiments of the present application, the first digital signal Dout and the second digital signal can have different numbers of bits, for example, the first digital signal Dout is an N-bit digital signal, and the second digital signal is an M-bit digital signal, and M and N are different integers.

[0068] Each digital gain modulation module 110 includes a digital gain unit 111 configured to amplify / reduce the first digital signal Dout by a preset coefficient. For example, the first digital signal Dout is 01010 (corresponding to the decimal number 10), and the preset coefficient is 1.1, so that the digital gain unit 111 outputs the amplified digital signal 01011 (corresponding to the decimal number 11). For another example, the first digital signal Dout is 0100 (corresponding to the decimal number 4), and the preset coefficient is 0.75, so that the digital gain unit 111 outputs the amplified digital signal 00011 (corresponding to the decimal number 3).

[0069] In some embodiments of the present application, for example, for the embodiment in which the feedback circuit 100 includes a plurality of digital gain modulation modules 110, the digital gain units 111 of the digital gain modulation modules 110 correspond to different preset coefficients. For example, the digital gain unit 111 of one digital gain modulation module 110 corresponds to a preset coefficient of 1.1, and the digital gain unit 111 of another digital gain modulation module 110 corresponds to a preset coefficient of 0.75. In some embodiments of the present application, the digital gain units 111 of the plurality of digital gain modulation modules 110 can correspond to the same preset coefficient partially or entirely. For example, the digital gain units 111 of two digital gain modulation modules 110 correspond to a preset coefficient of 1.1, and the digital gain unit 111 of another digital gain modulation module 110 corresponds to a preset coefficient of 1.2.

[0070] In some embodiments of the present application, the second digital signal can refer to the digital signal output by the digital gain unit 111, for example, in the embodiment where the first digital signal Dout is 01010, the preset coefficient is 1.1, and the digital signal output by the digital gain unit 111 is the amplified 01011, the digital signal 01011 output by the digital gain unit 111 is the second digital signal output by the digital gain modulation module 110 in the current measurement period. In some embodiments of the present application, the second digital signal can also refer to the digital signal obtained by the digital gain modulation module 110 through further modulation processing based on the digital signal output by the digital gain unit 111.

[0071] The charge feedback module 120 is configured to output a charge signal based on at least one second digital signal and at least one preset reference voltage in each measurement period, so that the target circuit 200 integrates the feedback charge signal to realize the analog-to-digital conversion or temperature measurement function.

[0072] As an exemplary, referring to FIG. 7, which shows another schematic diagram of the feedback circuit 100 and the target circuit 200 in the embodiments of the present application, the charge feedback module 120 includes a plurality of fifth switches S5, sixth switches S6 and capacitors CR. The second digital signal D1 is used to control the opening or closing of the plurality of fifth switches S5 and sixth switches S6. The fifth switch S5 controls whether the capacitor CR is connected to the preset reference voltage V1, and the sixth switch S6 controls whether the capacitor CR is grounded. Taking the fifth switch S5 as an NMOS tube and the sixth switch as a PMOS tube as an example, when a certain bit of the second digital signal is “1” (representing high level), the fifth switch S5 is closed and the sixth switch S6 is opened, the capacitor CR is charged, and the charge amount of the capacitor CR is CRxV1. After the certain bit of the second digital signal is converted from “1” (representing high level) to “0” (representing low level), the fifth switch S5 is opened and the sixth switch S6 is closed, then the capacitor CR is discharged and outputs a charge signal with a charge amount of -CRxV1. Conversely, when a certain bit of the second digital signal D1 is “0”, the capacitor CR outputs a charge signal with a charge amount of +CRxV1.

[0073] That is, the more bits of “1” in the second digital signal, the fewer bits of “0” in the second digital signal, and the more negative charges are fed back by the feedback circuit 100. Conversely, the more bits of “0” in the second digital signal, the fewer bits of “1” in the second digital signal, and the more positive charges are fed back by the feedback circuit 100.

[0074] It can be understood that, Fig. 7 is exemplarily illustrated by taking the example that the charge feedback module 120 outputs a charge signal according to a second digital signal and a preset reference voltage, but is not limited thereto. For example, referring to Fig. 8, Fig. 8 shows another schematic diagram of the feedback circuit 100 and the target circuit 200 in the embodiment of the present application, and different from Fig. 7, the same charge feedback module 120 is connected with a preset reference voltage V1 and a preset reference voltage V2, and the charge feedback module 120 outputs a charge signal according to a second digital signal and the two preset reference voltages V1 and V2; for another example, referring to Fig. 9, Fig. 9 shows another schematic diagram of the feedback circuit 100 and the target circuit 200 in the embodiment of the present application, and different from Fig. 7, the same charge feedback module 120 is connected with two second digital signals D1 and D2 output by the two digital gain modulation modules 110, and the charge feedback module 120 outputs a charge signal according to the two second digital signals D1 and D2 and the two preset reference voltages V1.

[0075] It should be noted that, the preset reference voltages shown in Figs. 7 to 9 are single-ended voltage signals, but are not limited thereto, and the preset reference voltages can also be differential voltage signals, which are not limited in the present application. Meanwhile, the input voltage signals shown in Figs. 5 to 9 are also single-ended voltage signals, and the corresponding circuit forms are also ordinary differential circuit forms. Those skilled in the art can modify the input voltage signals to differential voltage signals and modify the circuit to a full differential circuit form according to Figs. 5 to 9, which is also included in the technical solutions protected by the claims of the present application.

[0076] In some embodiments of the present application, for example, for the embodiment in which the target circuit 200 can perform analog-to-digital conversion according to the charge signal fed back by the feedback circuit, when the target circuit 200 performs analog-to-digital conversion according to the charge signal fed back by the feedback circuit, the first ratio between the average value of the second digital signal output by each digital gain modulation module 110 and the average value of the first digital signal Dout is equal to a preset coefficient, that is, the average value of the second digital signal corresponding to a digital gain modulation module 110, the average value of the first digital signal, and the preset coefficient satisfy the following relationship:

[0077] Wherein, K is the preset coefficient, D1_AV is the average value of the first digital signal, and D2_AV is the average value of the second digital signal.

[0078] For example, for the embodiment in which the second digital signal refers to the digital signal output by the digital gain unit 111, since the second digital signal is the first digital signal Dout amplified by a preset coefficient, after a plurality of measurement periods, the first ratio between the average value of the second digital signal output by each digital gain modulation module 110 and the average value of the first digital signal Dout is equal to the preset coefficient, and thus, when the target circuit 200 needs to be calibrated, the preset coefficient of the digital gain modulation module 110 can be adjusted to achieve gain calibration.

[0079] For example, the input voltage signal input into the target circuit 200 has a voltage value of 2.2V, and the analog-to-digital conversion result output by the target circuit 200 is 01010 (corresponding to the decimal number 10, and corresponding to a voltage value of 2V), and thus the target gain calibration coefficient of the target circuit 200 is 2.2V / 2V = 1.1. After the preset coefficient K1 of the digital gain unit 111 is set to 1.1, the digital gain unit 111 scales the proportion by 10 times to 11 times, and when the first digital signal Dout output by the target circuit 200 in a measurement period is "1", the second digital signal obtained by the digital gain unit 111 scaling by 11 times is 01011 (corresponding to the decimal number 11), and the charge amount of the charge feedback signal fed back by the charge feedback module 120 under the control of the second digital signal is changed. After a plurality of measurement periods, the input charge signal output by the input sampling module 210 and the feedback charge signal of the feedback circuit 100 satisfy: Vin x C x N = Q0 x K1

[0080] wherein K1 is the gain coefficient of the digital gain unit 111.

[0081] It can be seen that, by the above formula combined with the first digital signal Dout output by the target circuit 200 in a plurality of measurement periods, the actual voltage value of the input voltage signal can be calculated, and thus, by changing the preset coefficient of the digital gain unit 111, the charge amount of the charge signal output by the charge feedback module 120 is actually changed, which is equivalent to achieving gain calibration of the target circuit 200 in the feedback link, and thus is conducive to ensuring the consistency between the input voltage signal and the output digital signal of the target circuit 200.

[0082] It should be noted that the "equal" in the present application does not mean absolute equal, but approximately equal. For example, for the embodiment that the first ratio between the average value of the second digital signal and the average value of the first digital signal Dout is equal to the preset coefficient, when the first ratio is within the range of the preset coefficient ± 2%, the first ratio can be considered equal to the preset coefficient. It can be understood that the ± 2% range is only exemplary, and those skilled in the art can reasonably set the fluctuation range in which the first ratio is considered equal to the preset coefficient according to actual needs (for example, the accuracy requirement of the analog-to-digital converter), and the present application does not make specific limitation.

[0083] Meanwhile, it should be pointed out that the average value of the digital signal (for example, the average value of the first digital signal, the average value of the second digital signal, the average value of the third digital signal) in the present application can be the average value calculated after the digital signals of each measurement period are summed, or can refer to the amplitude in the frequency domain obtained after the digital signal is processed by filtering (for example, first-order low-pass filtering or second-order low-pass filtering).

[0084] In some embodiments of the present application, referring to FIG. 10, FIG. 10 shows another schematic diagram of the feedback circuit 100 and the target circuit 200 in the embodiments of the present application, wherein the feedback circuit 100 includes a plurality of digital gain modulation modules 110 and a plurality of charge feedback modules 120, and the charge feedback modules 120 correspond to the digital gain modulation modules 110 one by one; each charge feedback module 120 accesses a preset reference voltage, and the second digital signal output by each digital gain modulation module 110 is used to control the corresponding charge feedback module 120 to output a charge signal based on the accessed preset reference voltage. That is, the preset coefficients K1, K2...Kn of the plurality of digital gain feedback modules can also be adjusted in the present application, so that the charge amount of the charge signals Q1, Q2...Qn output by the plurality of charge feedback modules can be changed, and the gain calibration of the target circuit 200 in the feedback link can also be performed.

[0085] In some embodiments of the present application, for example, for the embodiment that the target circuit 200 can perform analog-to-digital conversion based on the feedback charge signal, referring to FIG. 11, FIG. 11 shows another schematic diagram of the feedback circuit 100 and the target circuit 200 in the embodiments of the present application, and the target circuit 200 performs analog-to-digital conversion gain calibration based on the target gain calibration coefficient K0; the second ratio of the sum of the products of the mutually corresponding preset coefficients and the preset reference voltages to the sum of the preset reference voltages is equal to the target gain calibration coefficient K0.

[0086] It should be noted that, since the first ratio between the average value of the second digital signal output by each digital gain modulation module 110 and the average value of the first digital signal Dout is equal to the preset coefficient after a plurality of measurement periods, the average charge amount output by each digital gain modulation module 110 in the plurality of measurement periods is: D1_AV×V1×C=Dout_AV×K1×V1×C D2_AV×V2×C=Dout_AV×K2×V2×C... Dn_AV×Vn×C=Dout_AV×Kn×Vn×C

[0087] wherein D1_AV, D2_AV...Dn_AV are the average values of the second digital signals, Dout_AV is the average value of the first digital signal Dout, K1, K2...Kn are the preset coefficients of the digital gain units 111 in the plurality of digital gain modulation modules 110, and V1, V2...Vn are the preset reference voltages accessed by the plurality of charge feedback modules 120.

[0088] The principle of the analog-to-digital conversion performed by the target circuit 200 is that the total amount (or average amount) of charges of the charge signal output by the feedback circuit 100 is equal to the total amount (or average amount) of charges of the input charge signal after a plurality of measurement periods, and it can be known that: Vin×C×N=(K1×V1+K2×V2+...+Kn×Vn)×Dout_AV×C×N

[0089] Therefore, the actual gain calibration coefficient of the target circuit 200 is: K=Vin / (Dout_AV)=(K1×V1+K2×V2+...+Kn×Vn) / (V1+V2+...+Vn)

[0090] wherein K is the actual gain calibration coefficient of the target circuit 200.

[0091] Since the second ratio of the sum of the products of the mutually corresponding preset coefficients and preset reference voltages to the sum of the preset reference voltages is equal to the target gain calibration coefficient in the above embodiment, i.e., the preset coefficients, preset reference voltages, and target gain coefficients satisfy the following formula: K0=(K1×V1+K2×V2+...+Kn×Vn) / (V1+V2+...+Vn)

[0092] Therefore, when the preset coefficients, preset reference voltages, and target gain coefficients satisfy the above formula, the actual gain calibration process of the target circuit 200 is completed, and thus when the feedback circuit 100 includes a plurality of digital gain modulation modules 110, the gain calibration of the target circuit can be completed by adjusting the preset coefficients K1, K2...Kn of the digital gain units 111 in the plurality of digital gain modulation modules 110 to satisfy the above formula.

[0093] It should be noted that the preset coefficient and the preset reference voltage corresponding to each other in the present application refer to the preset coefficient of the digital gain unit 111 in the digital gain modulation module 110 and the preset reference voltage corresponding to the second digital signal output by the digital gain modulation module 110 and outputting the charge signal. For example, in FIG. 11, V1 and K1 are the preset coefficient and the preset reference voltage corresponding to each other, V2 and K2 are the preset coefficient and the preset reference voltage corresponding to each other, and Vn and Kn are the preset coefficient and the preset reference voltage corresponding to each other.

[0094] In some embodiments of the present application, for example, for the embodiment in which the target circuit 200 can perform analog-to-digital conversion according to the feedback charge signal, after a plurality of measurement periods, the average charge amount of the charge signal output by the feedback circuit 100 does not change with the change of the ambient temperature.

[0095] It should be noted that, according to the foregoing, the principle of analog-to-digital conversion of the target circuit 200 is that after a plurality of measurement periods, the average charge amount of the charge signal output by the feedback circuit 100 is equal to the charge amount of the input charge signal, i.e., Vin×C=QR_AV

[0096] Wherein QR_AV is the average charge amount output by the feedback circuit 100 after a plurality of measurement periods.

[0097] Since in the above embodiment, the average charge amount of the charge signal output by the feedback circuit 100 does not change with the change of the ambient temperature, for the analog-to-digital conversion of the same input voltage signal, the phenomenon that the analog-to-digital conversion accuracy of the input voltage signal decreases due to the change of the ambient temperature will not occur.

[0098] In some embodiments of the present application, the preset reference voltage accessed by the at least one charge feedback module 120 has a positive temperature coefficient, and the preset reference voltage accessed by the at least one charge feedback module 120 has a negative temperature coefficient; after a plurality of measurement periods, the sum of the products of the preset coefficient and the preset reference voltage corresponding to each other does not change with the change of the ambient temperature.

[0099] For example, refer to FIG. 12, which shows another schematic diagram of the feedback circuit 100 and the target circuit 200 in the embodiments of the present application, where the feedback circuit 100 includes two digital gain modulation modules 110 and two charge feedback modules 120, one of which accesses a preset reference voltage V1 with a positive temperature coefficient, and the other of which accesses a preset reference voltage V2 with a negative temperature coefficient. As described above, after a plurality of measurement periods, the average charge quantity output by the feedback circuit 100 over the plurality of measurement periods is: QR_AV=D1_AV×V1×C+D2_AV×V2×C=Dout_AV(K1×V1+K2×V2)×C

[0100] In the above embodiments, the sum of the products of the corresponding preset coefficients and preset reference voltages (i.e., K1×V1+K2×V2) does not change with the change in ambient temperature, and the capacitance value of the capacitor does not substantially change with temperature, so the average charge quantity output by the feedback circuit 100 over a plurality of measurement periods does not change with temperature, thereby avoiding the influence of ambient temperature on the analog-to-digital conversion accuracy of the target circuit 200.

[0101] Taking a first-order temperature coefficient voltage as the preset reference voltage, the preset reference voltages V1 and V2 accessed by the two charge feedback modules 120 satisfy the following formula: V1=V01+kx×△T V2=V02+ky×△T

[0102] where kx is a first-order positive temperature coefficient, ky is a first-order negative temperature coefficient, △T is the difference between the ambient temperature and a set temperature (e.g., 25°C), and V01 and V02 are the voltage values of the preset reference voltages V1 and V2 at the set temperature (e.g., 25°C).

[0103] If the first-order positive temperature coefficient kx is 0.5 and the first-order negative temperature coefficient ky is -0.6, and the preset coefficients K1 and K2 are 1.2 and 1, respectively, then the sum of the products of the corresponding preset coefficients and preset reference voltages is: 1.2×V01+V02. As can be seen, this formula does not contain any temperature coefficient, so the preset coefficients K1, K2,..., Kn of the digital gain units 111 in the plurality of digital gain modulation modules 110 can be changed, so that the sum of the products of the corresponding preset coefficients and preset reference voltages does not change with the change in ambient temperature, and ultimately the influence of temperature on the analog-to-digital conversion of the target circuit is avoided.

[0104] In some embodiments of the present application, for example, for embodiments in which the target circuit 200 measures the temperature based on the charge signal input by the feedback circuit 100, after a plurality of measurement periods, the average charge quantity of the charge signal output by the feedback circuit 100 changes with the change in ambient temperature, so as to facilitate the target circuit 200 to measure the ambient temperature.

[0105] In some embodiments of the present application, the preset reference voltages accessed by the at least one charge feedback module 120 have positive temperature coefficients, and the preset reference voltages accessed by the at least one charge feedback module 120 have negative temperature coefficients; after a plurality of measurement periods, the sum of the products of the corresponding preset coefficients and preset reference voltages does not change with the change of the ambient temperature, and the at least one charge feedback module 120 accesses the third digital signal Din and outputs a charge signal based on the third digital signal Din and the preset reference voltage with the temperature coefficient.

[0106] For example, referring to FIG. 13, FIG. 13 shows another schematic diagram of the feedback circuit 100 and the target circuit 200 in embodiments of the present application, in which one charge feedback module 120 accesses a preset reference voltage V1 with a positive temperature coefficient, and another charge feedback module 120 accesses a preset reference voltage V2 with a negative temperature coefficient. The charge feedback module 120 accessing the preset reference voltage V2 outputs a charge signal according to the third digital signal Din in each measurement period, and then the average charge quantity of the charge signal output by the feedback circuit 100 in a plurality of measurement periods satisfies the following formula: QR_AV = Dout_AV(K1 x V1 + K2 x V2) x C + Din x V2 x C = 0 Dout_AV(K1 x V1 + K2 x V2) x C = -Din x V2 x C

[0107] It can be seen that, since in the above embodiments, the sum of the products of the corresponding preset coefficients and preset reference voltages does not change with the change of the ambient temperature, and the at least one charge feedback module 120 accesses the third digital signal Din and outputs a charge signal based on the third digital signal Din and the preset reference voltage with the temperature coefficient, the average charge quantity of the charge signal output by the feedback circuit 100 will change with the change of the ambient temperature, and at this time the function of the target circuit 200 is actually relative to quantizing the charge signal corresponding to the third digital signal Din by the charge signal corresponding to the second digital signal, so that the conversion code value of the charge signal corresponding to the third digital signal Din can be obtained at the output end of the analog quantization module 230, and finally the ambient temperature value can be obtained according to the conversion code value.

[0108] As an exemplary example, referring to FIG. 14, FIG. 14 shows a schematic diagram of a charge feedback module 120 in embodiments of the present application, in which one group of switches S5, S6 is controlled by the third digital signal Din, and the remaining group of switches S5, S6 is controlled by the second digital signal, so that the charge feedback module 120 accesses the third digital signal Din and outputs a charge signal based on the third digital signal Din and the preset reference voltage V2 with the temperature coefficient.

[0109] In some embodiments of the present application, for example, for embodiments in which the target circuit 200 can be subjected to analog-to-digital conversion or temperature measurement, the preset reference voltage to which the at least one charge feedback module 120 is connected has a first-order negative temperature coefficient and a second-order negative temperature coefficient; the preset reference voltage to which the at least one charge feedback module 120 is connected has a first-order positive temperature coefficient, and the preset reference voltage to which the at least one charge feedback module 120 is connected has a second-order positive temperature coefficient. That is, by controlling the preset coefficients of the digital gain units 111 in the plurality of digital gain modulation modules 110, the influence of the first-order temperature coefficient and the second-order temperature coefficient can also be eliminated, thereby further improving the accuracy of analog-to-digital conversion and temperature measurement.

[0110] For example, referring to FIG. 15, FIG. 15 shows another schematic diagram of the feedback circuit 100 and the target circuit 200 in an embodiment of the present application. The plurality of digital gain modulation modules 110 includes a first digital gain modulation module 1101, a second digital gain modulation module 1102, and a third digital gain modulation module 1103, and the plurality of charge feedback modules 120 includes a first charge feedback module 1201, a second charge feedback module 1202, and a third charge feedback module 1203. The first charge feedback module 1201 is connected to a first preset reference voltage V1 having a first-order negative temperature coefficient and a second-order negative temperature coefficient and a second digital signal output by the first digital gain modulation module 1101. The second charge feedback module 1202 is connected to a second preset reference voltage V2 having a first-order positive temperature coefficient and a second digital signal output by the second digital gain modulation module 1102. The third charge feedback module 1203 is connected to a third preset reference voltage V3 having a second-order positive temperature coefficient and a second digital signal output by the third digital gain modulation module 1103.

[0111] For example, the first preset reference voltage V1, the second preset reference voltage V2, and the third preset reference voltage V3 satisfy the following formulae: 2 V2 = V02 + ky1 x AT V3 = V03 + kz2 x AT 2

[0112] wherein kx1 and ky1 are first-order temperature coefficients, kx2 and kz2 are second-order temperature coefficients, AT is the difference between the ambient temperature and a set temperature (for example, 25°C), and V01, V02, and V03 are the voltage values of the preset reference voltages V1, V2, and V3 at the set temperature (for example, 25°C).

[0113] To meet the target gain calibration coefficient K0 requirement and eliminate the influence of the first order temperature coefficient and the second order temperature coefficient, the following formulas need to be met: K1×kx1=K2×ky1 K1×kx2=K3×kz2 K0=(K1×V01+K2×V02+K3×V03) / (V01+V02+V03)

[0114] It can be seen that in the above formulas kx1, ky1, kx2, kz2, V01, V02, V03, K0 are known numbers, and K1, K2, K3 are unknown numbers. In this case, the above three formulas can be solved to obtain a unique solution of K1, K2, K3, which ultimately ensures that the target circuit 200 achieves the target gain calibration coefficient and eliminates the influence of the first order temperature coefficient and the second order temperature coefficient.

[0115] In some embodiments of the present application, for example, for the embodiment in which the second digital signal refers to the digital signal obtained by further modulation processing of the digital signal output by the digital gain unit 111, referring to FIG. 16, FIG. 16 shows another schematic diagram of the feedback circuit 100 and the target circuit 200 in the embodiments of the present application, wherein each digital gain modulation module 110 further comprises a digital integration unit 112 and a digital quantization unit 113; the digital gain unit 111 is configured to output a gain digital signal Dgain according to the first digital signal Dout in each measurement period; the digital integration unit 112 is configured to integrate the gain digital signal Dgain input in the current measurement period and the second digital signal fed back in the last measurement period to output an integrated digital signal Dint corresponding to the current measurement period; and the digital quantization unit 113 is configured to compare the integrated digital signal Dint with a preset digital signal DR in each measurement period and output the second digital signal.

[0116] For example, in the first measurement period, the first digital signal Dout output by the target circuit 200 is 1, the gain digital signal Dgain output by the digital gain unit 111 in a certain digital gain modulation module 110 is 1.2, and the integral digital signal Dint output by the digital integral unit 112 is recorded as 1.2. Since the integral digital signal Dint is greater than the preset digital signal DR (for example, the preset digital signal DR is equal to 0), the digital quantization unit 113 outputs the second digital signal as 1. In the second measurement period, the first digital signal Dout output by the target circuit 200 is 0, the gain digital signal Dgain output by the digital gain unit 111 in a certain digital gain modulation module 110 is 0, the digital integral unit 112 integrates the second digital signal fed back from the last measurement period, and the integral digital signal Dint output by the digital integral unit 112 is recorded as 0.2. Since the integral digital signal Dint is still greater than the preset digital signal DR, the digital quantization unit 113 still outputs the second digital signal as 1. In the third measurement period, the first digital signal Dout output by the target circuit 200 is 0, the gain digital signal Dgain output by the digital gain unit 111 in a certain digital gain modulation module 110 is 0, the digital integral unit 112 integrates the second digital signal fed back from the last measurement period, and the integral digital signal Dint output by the digital integral unit 112 is recorded as -0.8. Since the integral digital signal Dint is less than the preset digital signal DR, the digital quantization unit 113 outputs the second digital signal as 0 and controls the feedback circuit 100 corresponding to the output charge signal, and so on.

[0117] As can be seen in the above exemplary process, the integral digital signal Dint output by the digital integral unit 112 approaches the preset digital signal DR (or approaches 0) after a plurality of measurement periods. Therefore, after a plurality of measurement periods, the first digital signal Dout and the second digital signal satisfy the following relationship: Dout1xK1+Dout2xK1+...+DoutnxK1=D11+D12+...+D1n

[0118] wherein D11, D12,..., D1n are respectively the second digital signals output by the same digital gain modulation module 110 in the first measurement period, the second measurement period,..., the Nth measurement period, and Dout1, Dout2,..., Doutn are respectively the first digital signals Dout output by the target circuit 200 in the first measurement period, the second measurement period,..., the Nth measurement period.

[0119] Meanwhile, the average value of the first digital signal Dout and the average value of the second digital signal can be calculated as follows: Dout_AV=(Dout1+Dout2+...+Doutn) / N D1_AV=(D11+D12+...+D1n) / N

[0120] According to the above formula, it can be known that: Dout_AV×K1=D1_AV

[0121] It can be seen that, although the second digital signal is not output by the digital gain unit 111, the digital gain modulation module 110 using the above embodiment also includes the digital integration unit 112 and the digital quantization unit 113, and the first ratio between the average value of the second digital signal output by each digital gain modulation module 110 and the average value of the first digital signal Dout after a plurality of measurement periods is equal to the preset coefficient. Finally, when the target circuit 200 needs to be calibrated, the gain calibration can be realized by adjusting the preset coefficient of the digital gain modulation module 110.

[0122] It can be understood that the digital gain unit 111, the digital integration unit 112 and the digital quantization unit 113 in the above embodiment can be realized by a digital circuit, which includes but is not limited to a digital logic circuit such as a gate circuit, a counter, a timer, a numerical comparator, etc.

[0123] In some embodiments of the present application, for example, for embodiments in which the target circuit 200 can measure temperature, when the target circuit 200 measures temperature based on the charge signal input by the feedback circuit 100, at least one digital gain modulation module 110 serves as a temperature digital gain modulation module, the digital integration unit 112 of the temperature digital gain modulation module further integrates the third digital signal Din in each measurement period, and the charge feedback module 120 outputs a charge signal according to the second digital signal D1 output by the temperature digital gain modulation module and the preset reference voltage with a temperature coefficient.

[0124] For example, referring to FIG. 17, FIG. 17 shows another schematic diagram of the feedback circuit 100 and the target circuit 200 in embodiments of the present application. In FIG. 17, the first preset reference voltage V1 has a first-order negative temperature coefficient and a second-order negative temperature coefficient, the second preset reference voltage V2 has a first-order positive temperature coefficient, and the third preset reference voltage V3 has a second-order positive temperature coefficient. The sum of the product of the corresponding preset coefficient and the preset reference voltage does not change with the change of the ambient temperature, i.e., the total feedback voltage V=V1×k1+V2×k2+V3×k3 zero temperature coefficient voltage.

[0125] The digital gain modulation module 110 corresponding to the preset reference voltage V2 is a temperature digital gain modulation module, and the digital integration unit 112 of the digital gain modulation module 110 is connected to the third digital signal Din. Since the digital integration unit 112 of the digital gain modulation module 110 integrates the third digital signal Din in each measurement period, the average value of the second digital signal D1 output by the digital gain unit 111 and the average value of the first digital signal Dout have a third ratio, the average value of the third digital signal Din and the average value of the first digital signal Dout have a fourth ratio, and the difference between the third ratio and the preset coefficient is equal to the fourth ratio, that is, the following relationship is satisfied:

[0126] It can be seen that the establishment of the above relationship makes the first ratio between the average value of the second digital signal output by the digital gain modulation module 110 and the average value of the first digital signal not equal to the preset coefficient. After a plurality of measurement periods, the charge feedback module 120 additionally increases the charge corresponding to the third digital signal Din based on the charge signal output by the second digital signal D1. Since the second preset reference voltage V2 has a first-order positive temperature coefficient, the charge corresponding to the third digital signal Din has a temperature coefficient and can be used for temperature measurement. Compared with the embodiment of FIG. 14, in which the third digital signal Din used for temperature measurement is directly input to the charge feedback module 120 for temperature measurement, the above embodiment can reuse all switches and capacitors of the charge feedback module 120 during analog-to-digital conversion and temperature measurement, so that switches and capacitors do not need to be set for temperature measurement, which is finally conducive to further reducing the circuit area.

[0127] It should be noted that the third digital signal Din can be a fixed digital signal input to the digital integration unit 112 in each measurement period, for example, the third digital signal Din is 0010, and the digital integration unit 112 integrates the third digital signal Din in each measurement period. The average value of the third digital signal Din in the above formula is 0010; or the third digital signal Din can also be a variable digital signal input to the digital integration unit 112 in each measurement period, for example, the third digital signal Din is 0011 in the first measurement period, the third digital signal Din is 0010 in the second measurement period, and the third digital signal Din is 0001 in the third measurement period. Taking the three measurement periods as an example, the average value of the third digital signal Din in the above formula is also 0010.

[0128] It should be noted that the above description of the feedback circuit 100 is intended to clearly illustrate the implementation of the verification process of the present application, and those skilled in the art can make equivalent modifications and designs under the guidance of the present application, for example, by generating a voltage with a temperature coefficient through an external circuit (resistor), and by inputting the voltage with a temperature coefficient into the sampling module 210 for analog-to-digital conversion to achieve temperature measurement; for another example, the above description of the digital integration unit 112 and the digital quantization unit 113 is actually a digital Sigma-Delta analog-to-digital converter, and those skilled in the art can also use similar digital analog-to-digital converters to achieve, for example, by using a digital successive approximation register (SAR) analog-to-digital converter or a digital flash analog-to-digital converter (Flash ADC) to output the second digital signal; for example, the digital flash analog-to-digital converter (Flash ADC) can include one or more value comparators to compare the gain digital signal Dgain output by the digital gain unit 111 to output the second digital signal.

[0129] In order to better implement the feedback circuit 100 in the embodiments of the present application, on the basis of the feedback circuit 100, the present application provides an analog-to-digital conversion circuit, which includes the feedback circuit 100 described in any of the above embodiments. The analog-to-digital conversion circuit can be, but is not limited to, a Sigma-Delta analog-to-digital converter, a hybrid analog-to-digital converter composed of a Sigma-Delta analog-to-digital converter and a successive approximation register analog-to-digital converter. Since the analog-to-digital conversion circuit of the present application includes the above feedback circuit 100, it has all the beneficial effects of the feedback circuit 100, which will not be repeated here.

[0130] In order to better implement the feedback circuit 100 in the embodiments of the present application, on the basis of the feedback circuit 100, the present application provides a temperature measurement circuit, which includes the feedback circuit 100 described in any of the above embodiments. Since the temperature measurement circuit of the present application includes the above feedback circuit 100, it has all the beneficial effects of the feedback circuit 100, which will not be repeated here.

[0131] The embodiments of the present application also provide a chip, which includes the above analog-to-digital conversion circuit or temperature measurement circuit. The chip (Integrated Circuit, IC) is also called a chip, which can be, but is not limited to, a SOC (System on Chip) chip or a SIP (system in package) chip.

[0132] The application further provides an electronic device, which comprises a device main body and the chip as described above arranged in the device main body. The electronic device can be, but is not limited to, a body weight scale, a body fat scale, a nutrition scale, an infrared electronic thermometer, a pulse oximeter, a human body composition analyzer, a mobile power supply, a wireless charger, a fast charger, a vehicle-mounted charger, an adapter, a display, a USB (Universal Serial Bus) docking station, a touch pen, a true wireless earphone, a car central control screen, a car, a smart wearable device, a mobile terminal, a smart home device. The smart wearable device includes, but is not limited to, a smart watch, a smart bracelet, a cervical vertebra massage instrument. The mobile terminal includes, but is not limited to, a smart phone, a notebook computer, a tablet computer, a POS (point of sales terminal) machine. The smart home device includes, but is not limited to, a smart socket, a smart rice cooker, a smart sweeper, a smart lamp.

[0133] The above is only a 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 preferred embodiment, it is not intended to limit the present application. Any person skilled in the art can make some changes or modifications to the equivalent embodiments with the disclosed technical content without departing from the scope of the present application. Any modification, change and modification of the above embodiments according to the technical essence of the present application are still within the scope of the present application.

Claims

1. A feedback circuit, wherein, The feedback circuit is used to feed back a charge signal to the input terminal of the target circuit based on the first digital signal output from the output terminal of the target circuit in each measurement cycle. The feedback circuit includes: At least one digital gain modulation module, each of the digital gain modulation modules being configured to output a second digital signal according to the first digital signal in each measurement cycle; At least one charge feedback module, each of the charge feedback modules being configured to output a charge signal in each measurement cycle based on at least one second digital signal and at least one preset reference voltage; Each of the digital gain modulation modules includes a digital gain unit for amplifying / scaling the first digital signal by a preset coefficient.

2. The feedback circuit as described in claim 1, wherein, When the target circuit performs analog-to-digital conversion based on the charge signal input by the feedback circuit, the first ratio between the average value of the second digital signal output by each of the digital gain modulation modules and the average value of the first digital signal is equal to the preset coefficient.

3. The feedback circuit as described in claim 1, wherein, The feedback circuit includes multiple digital gain modulation modules and multiple charge feedback modules, with each charge feedback module corresponding to a digital gain modulation module. Each of the charge feedback modules is connected to a preset reference voltage, and the second digital signal output by each of the digital gain modulation modules is used to control the corresponding charge feedback module to output a charge signal based on the preset reference voltage.

4. The feedback circuit as described in claim 3, wherein, When the target circuit performs analog-to-digital conversion based on the charge signal input from the feedback circuit, the target circuit performs analog-to-digital conversion gain calibration based on the target gain calibration coefficient; The second ratio of the sum of the products of the corresponding preset coefficients and the preset reference voltages to the sum of the preset reference voltages is equal to the target gain calibration coefficient.

5. The feedback circuit as described in claim 4, wherein, The preset reference voltage connected to at least one of the charge feedback modules has a positive temperature coefficient, and the preset reference voltage connected to at least one of the charge feedback modules has a negative temperature coefficient. The sum of the products of the corresponding preset coefficients and the preset reference voltage does not change with the change of ambient temperature.

6. The feedback circuit as described in claim 3, wherein, The preset reference voltage connected to at least one of the charge feedback modules has a positive temperature coefficient, and the preset reference voltage connected to at least one of the charge feedback modules has a negative temperature coefficient. The sum of the products of the corresponding preset coefficients and the preset reference voltage does not change with the change of ambient temperature, and at least one of the charge feedback modules is connected to a third digital signal and outputs a charge signal based on the third digital signal and the preset reference voltage with a temperature coefficient.

7. The feedback circuit as described in claim 5 or 6, wherein, The preset reference voltage connected to at least one of the charge feedback modules has a first-order negative temperature coefficient and a second-order negative temperature coefficient. The preset reference voltage connected to at least one of the charge feedback modules has a first-order positive temperature coefficient, and the preset reference voltage connected to at least one of the charge feedback modules has a second-order positive temperature coefficient.

8. The feedback circuit as described in claim 1, wherein, Each of the digital gain modulation modules further includes a digital integration unit and a digital quantization unit; The digital gain unit is used to output a gain digital signal based on the first digital signal in each measurement cycle; The digital integration unit is used to integrate the gain digital signal input in the current measurement cycle and the second digital signal fed back in the previous measurement cycle, so as to output the integrated digital signal corresponding to the current measurement cycle. The digital quantization unit is used to compare the integral digital signal with a preset digital signal in each measurement cycle and output the second digital signal.

9. The feedback circuit as described in claim 8, wherein, When the target circuit performs temperature measurement based on the charge signal input from the feedback circuit, at least one of the digital gain modulation modules serves as a temperature digital gain modulation module. In each measurement cycle, the digital integration unit of the temperature digital gain modulation module integrates the third digital signal, and the charge feedback module outputs a charge signal based on the second digital signal output by the temperature digital gain modulation module and the preset reference voltage with a temperature coefficient.

10. An analog-to-digital converter circuit, wherein, Includes the feedback circuit as described in any one of claims 1 to 9.

11. A temperature measuring circuit, wherein, Includes the feedback circuit as described in any one of claims 1 to 9.

12. A chip, wherein, This includes the analog-to-digital conversion circuit as described in claim 10 or the temperature measurement circuit as described in claim 11.

13. An electronic device, wherein, Including the chip as described in claim 12.

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