CN210016452U

CN210016452U - Control circuit of voltage digital converter and resistance sensor reading circuit

Info

Publication number: CN210016452U
Application number: CN201920243169.8U
Authority: CN
Inventors: 黎冰; 林尔城
Original assignee: Shenzhen University
Current assignee: Shenzhen University
Priority date: 2019-02-26
Filing date: 2019-02-26
Publication date: 2020-02-04
Anticipated expiration: 2029-02-26

Abstract

A control circuit of a voltage-to-digital converter and a resistance sensor readout circuit, the control circuit of the voltage-to-digital converter comprises: a switching module configured to switch in or switch off the reference voltage and/or the common mode voltage according to a first control signal; the energy storage module is connected with the switch module and is configured to be charged or discharged according to the reference voltage and the common-mode voltage; the modulation module is connected with the energy storage module and is configured to output an integral voltage after delta sigma modulation feedback is carried out on the charge output by the energy storage module; the quantizer is connected with the modulation module and is configured to quantize the integrated voltage according to the second control signal to obtain a digital coding signal; the embodiment of the utility model provides an in the modulation module can realize electric energy multiplex, has reduced voltage digital converter's control circuit's total consumption to can filter the interference component among the voltage conversion process through delta sigma modulation feedback, be favorable to having improved the digital coding signal's of quantizer output precision and resolution ratio.

Description

Control circuit of voltage digital converter and resistance sensor reading circuit

Technical Field

The utility model belongs to the technical field of electronic circuit, especially, relate to a voltage digital converter's control circuit and resistance sensor read-out circuit.

Background

With the rapid development of electronic technology, voltage detection technology has been rapidly developed; in the practical application process, a technician directly obtains related performance parameters of the measured object, and particularly when the performance parameters of the measured object are presented in the form of non-electric quantity (such as pressure, stress, displacement, micro deformation and the like), the non-electric quantity performance parameters can only be converted into voltage and the like; when the voltage value of the object to be measured is obtained, the working state of the object to be measured can be obtained through detection and analysis of the voltage value, for example, a series of data such as temperature, pressure, humidity and deformation of the object to be measured can be obtained through the voltage value variation of the object to be measured; however, in the process of processing and analyzing the voltage value of the object to be measured, the voltage value of the object to be measured detected by the detection circuit is only an analog quantity, and a technician cannot directly perform operation processing on the analog quantity, and the analog quantity needs to be converted into a digital signal, for example, the amplitude value of the voltage analog quantity is expressed by a binary coding signal; therefore, the voltage detection method in the conventional technology must use a digital converter to convert the continuous voltage analog quantity into a digital signal recognizable by an external computer device, and implement a real-time processing function for the voltage value through the digital signal.

In the digital converter in the conventional technology, the analog-to-digital conversion device needs a stable current source bias, and the current source is used for driving the digital converter to realize the analog-to-digital conversion function; if the technician wants to obtain a higher signal-to-noise ratio, the digitizer must use a bias current with a larger power, which results in a larger power consumption of the digitizer; if a technician uses some methods to reduce the power consumption of the digitizer, the operating state of the electronic components in the digitizer is greatly affected, the precision and resolution of the digital signal output by the digitizer cannot be guaranteed, the corresponding voltage value cannot be accurately obtained through the digital signal, the control precision and control response speed of the digitizer are reduced, and the user experience is poor.

SUMMERY OF THE UTILITY MODEL

In view of this, the embodiment of the present invention provides a control circuit of a voltage-to-digital converter and a resistance sensor readout circuit, which aim to solve the problems that the voltage-to-digital converter in the conventional technical solution has large power consumption, the stability of signal conversion is poor, and the precision and resolution of the digital signal obtained by the voltage-to-digital converter are low.

The utility model discloses a first aspect of the embodiment provides a voltage digital converter's control circuit, include:

a switching module configured to switch in or switch off the reference voltage and/or the common mode voltage according to a first control signal;

the energy storage module is connected with the switch module and is configured to be charged or discharged according to the reference voltage and the common-mode voltage;

the modulation module is connected with the energy storage module and is configured to output an integral voltage after modulating and feeding back the charge output by the energy storage module; and

and the quantizer is connected with the modulation module and is configured to quantize the integrated voltage according to a second control signal to obtain a digital coding signal.

In one embodiment thereof, the switch module comprises: the first switch tube and the second switch tube; the first control signal includes: a first drive signal and a second drive signal;

the first conducting end of the first switching tube is connected to the reference voltage, the first conducting end of the second switching tube is connected to the common-mode voltage, and the second conducting end of the first switching tube and the second conducting end of the second switching tube are connected to the energy storage module in common;

the control end of the first switch tube is connected with the first driving signal, and the first switch tube is switched on or off according to the level state of the first driving signal;

the control end of the second switch tube is connected to the second driving signal, and the second switch tube is switched on or off according to the level state of the second driving signal.

In one embodiment, the level state of the first driving signal and the level state of the second driving signal satisfy the following condition:

in the above equation, "+" represents a logical and operation of signals, N1 is a level state of a first driving signal, N2 is a level state of a second driving signal, Y is 0 or 1, and

is the inverse value of said Y, said phi_1dIs a first level signal, said phi_2dIs a second level signal, and the phases of the first level signal and the second level signal are staggered.

In one embodiment thereof, the energy storage module comprises: a first capacitor;

the first end of the first capacitor is connected with the switch module, and the second end of the first capacitor is connected with the modulation module.

In one embodiment thereof, the modulation module comprises:

the switching unit is connected with the energy storage module and is configured to be switched on or switched off according to a switching signal, and the switching unit transfers and regulates the electric charge output by the energy storage module; and

the zero crossing unit is connected between the switching unit and the quantizer and is configured to integrate and compare and amplify the charges output by the energy storage module to output the integrated voltage.

In one embodiment, the switching signal comprises a first switching signal and a second switching signal;

the switching unit includes: the variable resistor, the third switching tube and the fourth switching tube;

the first conducting end of the third switching tube is connected to the common-mode voltage, the second conducting end of the third switching tube and the first end of the variable resistor are connected to the energy storage module in a shared mode, the second end of the variable resistor is connected to the first conducting end of the fourth switching tube, and the second conducting end of the fourth switching tube is connected to the zero-crossing unit;

the control end of the third switching tube is connected with the first switching signal, and the third switching tube is switched on or off according to the level state of the first switching signal;

and the control end of the fourth switching tube is connected with the second switching signal, and the fourth switching tube is switched on or off according to the level state of the second switching signal.

In one embodiment, the phases of the first and second switching signals are interleaved.

In one embodiment thereof, the quantizer comprises: the circuit comprises a first voltage input end, a second voltage input end, a control end and a digital signal output end;

a first voltage input end of the quantizer is connected with the zero-crossing unit, a second voltage input end of the quantizer is connected with the common-mode voltage, a control end of the quantizer is connected with the second control signal, and the quantizer works or stops according to the level state of the second control signal;

when the quantizer works, the quantizer performs a differential operation on the integrated voltage and the common-mode voltage to generate the digital coding signal, and a digital signal output end of the quantizer outputs the digital coding signal;

the phase of the second control signal is the same as the phase of the second switching signal.

In one embodiment thereof, the zero crossing unit comprises: the comparator, the integrating capacitor, the fifth switching tube and the constant current source;

the first input end of the comparator is connected to the common-mode voltage, the second input end of the comparator and the first end of the integrating capacitor are connected to the switch unit in common, the second end of the integrating capacitor, the first conducting end of the fifth switch tube, the output end of the comparator and the first end of the constant current source are connected to the quantizer in common, and the second end of the constant current source is grounded;

the second end of the fifth switching tube is connected with a first direct current power supply;

and the control end of the fifth switching tube is connected with a third driving signal, and the fifth switching tube is switched on or switched off according to the level state of the third driving signal.

A second aspect of the embodiments provides a resistance sensor readout circuit, include:

a current source configured to output a drive current;

a resistance sensor connected to the current source and configured to change its resistance value according to an external disturbance amount;

the voltage converter is connected with the resistance sensor and is configured to collect the variation of the operating current of the resistance sensor and convert the variation of the operating current into reference voltage; and

as mentioned above, the control circuit of the voltage-to-digital converter is connected to the voltage converter, and the control circuit of the voltage-to-digital converter is connected to the reference voltage and converts the reference voltage into a digital code signal.

The control circuit of the voltage digital converter can continuously realize the function of analog-digital conversion so as to stably output digital coding signals and improve the practical value of the control circuit of the voltage digital converter; simultaneously the embodiment of the utility model provides an in the modulation module adopts delta sigma modulation method to the electric charge, in time filters the noise component in the reference voltage, has avoided signal distortion problem in the voltage signal conversion process, the utility model provides an in the embodiment quantizer can obtain more real voltage value, digital code signal can change according to the change of reference voltage, analog-to-digital conversion's precision is higher, and response speed is faster, can obtain higher resolution ratio; therefore, the control circuit of the voltage digital converter in the embodiment of the utility model can greatly improve the voltage sampling precision, and bring better use experience to users; the problems that in the prior art, the power consumption of a control circuit of the voltage digital converter is overlarge and the precision and the resolution of a digital signal are low are solved.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the embodiments or the prior art descriptions will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without inventive labor.

Fig. 1 is a schematic structural diagram of a control circuit of a voltage-to-digital converter according to an embodiment of the present invention;

fig. 2 is a schematic structural diagram of a modulation module according to an embodiment of the present invention;

fig. 3 is a specific circuit structure of a control circuit of a voltage-to-digital converter according to an embodiment of the present invention;

fig. 4 is a comparative reference circuit structure of the control circuit of the voltage-to-digital converter in fig. 3 according to an embodiment of the present invention;

fig. 5 is a waveform graph of each control signal according to an embodiment of the present invention;

fig. 6 is an equivalent circuit analysis diagram of the control circuit of the voltage-to-digital converter in fig. 3 according to an embodiment of the present invention;

fig. 7 is a waveform diagram of each control signal and each node voltage according to an embodiment of the present invention;

fig. 8 is a structural diagram of an equivalent circuit of the control circuit of the voltage-to-digital converter in fig. 6 according to an embodiment of the present invention;

fig. 9 is a diagram of another equivalent circuit structure of the control circuit of the voltage-to-digital converter in fig. 6 according to an embodiment of the present invention;

fig. 10 is a waveform diagram of an integrated voltage output by the integrator according to an embodiment of the present invention;

fig. 11 is a schematic structural diagram of a resistance sensor readout circuit according to an embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Referring to fig. 1, a schematic structural diagram of a control circuit 10 of a voltage-to-digital converter according to an embodiment of the present invention is provided, where the control circuit 10 of the voltage-to-digital converter can implement a precise analog-to-digital conversion function of voltage, for convenience of description, only the parts related to this embodiment are shown, and detailed descriptions are as follows:

as shown in fig. 1, the control circuit 10 of the voltage-to-digital converter includes: a switching module 101, a storage module 102, a modulation module 103, and a quantizer 104.

The switch module 101 switches on or off the reference voltage Vref and/or the common mode voltage Vcom according to the first control signal.

Optionally, the switch module 101 is turned on or off according to a level state of the first control signal C1; illustratively, when the first control signal C1 is in a first level state, the switch module 101 is turned on, and when the first control signal C1 is in a second level state, the switch module 101 is turned off, wherein the first control signal includes circuit on-off control information, and the on-state or off-state of the switch module 101 can be changed in time by the level state of the first control signal; the switch module 101 can implement a voltage transmission function, and therefore the switch module 101 in this embodiment has a high control response speed.

It should be noted that the first level state is a high level state or a low level state, and the phases of the first level state and the second level state are staggered; illustratively, the first level state is a high level state, and the second level state is a low level state.

In this embodiment, when the switch module 101 is connected to the reference voltage Vref and/or the common mode voltage Vcom; the reference voltage Vref and the common mode voltage Vcom include corresponding voltage information, and when the voltage information changes, the electric energy accessed by the control circuit 10 of the voltage-to-digital converter also changes correspondingly; the original driving power can be provided to the control circuit 10 of the voltage digital converter by the reference voltage Vref, and the control circuit 10 of the voltage digital converter can be in a stable working state by the reference voltage Vref and the common mode voltage Vcom; the electric energy input state of the control circuit 10 of the voltage digital converter has a circuit structure with good controllability and flexibility, the control circuit 10 of the voltage digital converter can perform analog-to-digital conversion according to an operation instruction of a technician, and the control circuit 10 of the voltage digital converter has higher practical value.

The energy storage module 102 is connected to the switching module 101 and configured to be charged or discharged according to the reference voltage Vref and the common mode voltage Vcom.

In the present embodiment, the energy storage module 102 has a function of storing electric energy, and the energy storage module 102 has a corresponding amount of electric charge; when the switch module 101 outputs different voltages to the energy storage module 102, the energy storage module 102 may charge or discharge according to the voltage output by the switch module 101, so as to realize the function of converting electric energy; furthermore, the control circuit 10 of the voltage-to-digital converter in this embodiment can change the amplitude of the electric energy, can more accurately obtain the fluctuation amount of the reference voltage according to the electric energy variation amount in the energy storage module 102, can realize a more accurate analog-to-digital conversion function through the electric charge amount on the energy storage module 102, and accelerates the analog-to-digital conversion efficiency of the control circuit 10 of the voltage-to-digital converter.

The modulation module 103 is connected to the energy storage module 102, and configured to perform Δ Σ modulation feedback on the charge output by the energy storage module 102 and output an integrated voltage.

The energy storage module 102 can be charged or discharged according to the on-state or off-state of the switch module 101, and the electric charge output by the energy storage module 102 can provide power supply energy for the modulation module 103, so that the modulation module 103 is in a stable working state; the charge output by the energy storage module 102 can provide bias electric energy for the modulation module 103, the charge accumulated in the modulation module 103 is changed through delta sigma modulation feedback, and the integration voltages output by the modulation module 103 are different when the switch module 101 is in different on or off time according to the first control signal; the modulation module 103 can perform noise removal processing on the charges output by the energy storage module 102 and reduce the fluctuation amount in the charges; the modulation module 103 can adaptively adjust the amplitude of the integrated voltage, so that the integrated voltage can change along with the input voltage of the switch module 101 in real time, which is beneficial to ensuring the conversion accuracy and conversion efficiency of the control circuit 10 of the voltage-to-digital converter in this embodiment for the voltage analog, and the control circuit 10 of the voltage-to-digital converter has higher dynamic modulation performance.

The quantizer 104 is connected to the modulation module 103 and configured to perform quantization processing on the integrated voltage according to a second control signal to obtain a digital coded signal.

The modulation module 105 outputs the integrated voltage to the quantizer 104, the quantizer 104 can obtain relevant voltage information, and the integrated voltage is classified according to the amplitude of the integrated voltage, where the integrated voltage represents the charge amplitude of each interval; the quantizer 104 is capable of converting analog quantity into digital mode, and the digital code signal belongs to discrete digital signal; wherein the second control signal can change the working state of the quantizer 104, so that the quantizer 104 can continuously and stably output the digital coding signal; illustratively, the level state of the second control signal can change the digital signal conversion function of the quantizer 104 in real time, and the control circuit 10 of the voltage-to-digital converter can output a corresponding digital coding signal only when the quantizer 104 is in a normal and stable working state; therefore, in the embodiment, the quantizer 104 can ensure the stability and reliability of the digital conversion function of the control circuit 10 of the voltage-to-digital converter, and the control circuit 10 of the voltage-to-digital converter can output corresponding digital signals in real time according to the variation of the voltage analog quantity, so that the practical value is extremely high; illustratively, the quantizer 104 is connected to an external mobile terminal, the quantizer 104 may directly output the digital code signal to the external mobile terminal, the digital code signal can be accurately identified and analyzed by the mobile terminal, and the external mobile terminal displays the specific amplitude of the voltage in real time, so as to bring better user experience to the user; the control circuit 10 of the voltage-to-digital converter in the present embodiment can be applied to various different technical fields, and has a very wide application range.

In the control circuit 10 of the voltage-to-digital converter shown in fig. 1, the switch module 101 can access voltage information, and the operating state of the switch module 101 can be changed according to the level state of the first control signal, so that the control circuit 10 of the voltage-to-digital converter can perform analog-to-digital conversion of voltage according to the actual requirement of a technician, and the controllability of the control circuit 10 of the voltage-to-digital converter is improved; the transmission form of the electric energy can be changed through the charging and discharging operations of the energy storage module 102, the electric energy multiplexing function can be provided for the modulation module 103 through the electric charge output by the energy storage module 102, the electric energy utilization rate output by the energy storage module 102 and the analog-to-digital conversion efficiency of the control circuit 10 of the voltage digital converter are ensured, the control circuit 10 of the voltage digital converter in the embodiment does not need to set a bias current specially provided for the modulation module 103, the power consumption of the control circuit 10 of the voltage digital converter is effectively reduced, and the space volume of the control circuit 10 of the voltage digital converter is saved; the amplitude of the charge output by the energy storage module 102 can be changed by a delta sigma modulation feedback method, adaptive adjustment of electric energy is realized, the integral voltage can be changed according to the change of the reference voltage Vref, the control circuit 10 of the voltage digital converter has higher signal-to-noise ratio, the accuracy and the resolution of the digital coding signal output by the quantizer 104 are improved, and higher analog-to-digital conversion performance can be realized by the control circuit 10 of the voltage digital converter; when the control circuit 10 of the voltage-to-digital converter outputs the voltage signal in the digital mode, the external circuit can realize intelligent analysis and processing on the voltage signal, so that good use experience is brought to a user, and the control circuit 10 of the voltage-to-digital converter has a very wide application range; the problems that in the prior art, the voltage analog quantity has larger power consumption in the process of carrying out analog-to-digital conversion, the voltage analog quantity is interfered by noise in the process of modulation conversion, the resolution of a digital signal converted by a control circuit of a traditional voltage digital converter is lower, the conversion rate of the signal is slower, and the universal application is difficult are effectively solved.

As an optional implementation, fig. 2 shows a schematic structure of the modulation module 103 provided in this embodiment, and compared with the control circuit 10 of the voltage-to-digital converter in fig. 1, the modulation module 103 in fig. 2 specifically includes: a switching unit 1031 and a zero-crossing unit 1032.

The switching unit 1031 is connected to the energy storage module 102, and configured to turn on or off according to a switching signal, transfer and adjust the electric charge output by the energy storage module 102.

Optionally, the switching unit 1031 is turned on or off according to a level state of the switching signal; for example, if the switching signal is in the first level state, the switching unit 1031 is turned on; when the switching signal is in the second level state, the switching unit 1031 is turned off; therefore, the switch unit 1031 in this embodiment has a more flexible control manner.

In the embodiment of the present invention, the signal modulation function of the modulation module 103 can be changed in time by the switch signal, so that the control circuit 10 of the voltage-to-digital converter can output the corresponding digital coding signal according to the actual requirement of the technician, thereby ensuring the practical value of the control circuit 10 of the voltage-to-digital converter; the integrity and stability of the electric charge output by the energy storage module 102 in the transmission process can be guaranteed through the switching unit 1031, and the amplitude and the transmission rate of the electric charge can be changed by the switching unit 1031, so that the electric charge amount in the control circuit 10 of the voltage-to-digital converter is always in a safe working state, and a normal mode conversion function can be realized according to the electric charge output by the switching unit 1031, and the digital coding signal output by the control circuit 10 of the voltage-to-digital converter can be adaptively changed according to the input voltage value.

The zero crossing unit 1032 is connected between the switching unit 1031 and the quantizer 104, and configured to integrate and compare and amplify the charges output by the energy storage module 102 to output the integrated voltage.

When the switching unit 1031 outputs the charges to the zero-crossing unit 1032, the errors in the charges can be eliminated by performing the integration operation on the charges, so that the interference of external interference quantity on the analog-to-digital conversion process of the charges is avoided, the change condition of the voltage analog quantity input by the control circuit 10 of the voltage-to-digital converter can be accurately mapped through the integrated charges, and the voltage-to-digital conversion precision can be ensured by performing the integration operation on the charges, so that the digital coding signals have higher steady-state values; meanwhile, after the amplitude of the electric charge is compared and amplified, the modulation precision of the modulation module 103 on the electric charge can be improved, and the zero-crossing unit 1032 can realize more accurate function on the electric charge according to an operation instruction; therefore, after the zero-crossing unit 1032 performs adaptive dynamic Δ Σ modulation feedback control through charges, the voltage information output by the zero-crossing unit 1032 can keep synchronous change with the voltage input by the control circuit 10 of the voltage-to-digital converter, and the digital conversion step for the analog voltage signal is optimized, so that the control circuit 10 of the voltage-to-digital converter can output an accurate digital signal according to the actual requirement of a technician, the application range of the control circuit 10 of the voltage-to-digital converter is improved, and the user experience is better.

As an alternative implementation, fig. 3 shows a specific circuit structure of the control circuit 10 of the voltage-to-digital converter provided in this embodiment, and as shown in fig. 3, the switch module 101 includes: a first switching tube M1 and a second switching tube M2; the first control signal includes: a first drive signal and a second drive signal;

when the first switch tube M1 and the second switch tube M2 are in different on or off states respectively, the switch module 101 transmits voltages with different amplitudes to the energy storage module 102, so as to realize different electric energy storage functions of the energy storage module 102.

The control end of the first switch tube M1 is connected to the first driving signal, and the first switch tube M1 is turned on or off according to the level state of the first driving signal; for example, when the first driving signal is in the first level state, the first conducting terminal and the second conducting terminal of the first switch transistor M1 are conducted; when the first driving signal is in the second level state, the first switch transistor M1 is turned off between the first conducting terminal and the second conducting terminal.

The control end of the second switch tube M2 is connected to the second driving signal, and the second switch tube M2 is turned on or off according to the level state of the second driving signal; for example, when the second driving signal is in the first level state, the first conducting terminal and the second conducting terminal of the second switch transistor M2 are conducted; when the second driving signal is in the second level state, the first conducting terminal and the second conducting terminal of the second switch tube M2 are turned off.

Illustratively, the first switching tube M1 is a MOS tube or a transistor, and the second switching tube M2 is a MOS tube or a transistor; for example, the first switch transistor M1 and the second switch transistor M2 are MOS transistors, and when the gates of the MOS transistors are connected to control signals in different levels, the drains and the sources of the MOS transistors are turned on or off to achieve different voltage transmission effects.

In the circuit structure of the switching module 101 in fig. 3, by combining the on or off states between the first switching tube M1 and the second switching tube M2, the switching module 101 can output voltages with different magnitudes, by which the charging or discharging operation of the energy storage module 102 can be realized; therefore, in the present embodiment, the charging and discharging control performance of the energy storage module 102 can be realized by utilizing the on-off effect between the first switching tube M1 and the second switching tube M2, the switching module 101 has a higher control response speed, and the energy storage module 102 can be switched in different voltages by combining the first switching tube M1 and the second switching tube M2, so that the controllability of the switching module 101 is improved; furthermore, the control circuit 10 of the voltage-to-digital converter can realize the digital conversion function of the voltage analog quantity according to the application requirements of the circuit, and has higher flexibility and stability.

As an alternative embodiment, the level state of the first driving signal and the level state of the second driving signal satisfy the following condition:

in the above equations (1) and (2), the "+" represents a logical or operation of signals, the N1 is a level state of a first driving signal, the N2 is a level state of a second driving signal, the Y is 0 or 1, and the Y is a logical or operation of signals

If the level states of the first driving signal and the second driving signal generated according to the above equation (1) and the above equation (2) are correlated, the on-off states of the first switching tube M1 and the second switching tube M2 are also correlated; for example, the first switch tube M1 and the second switch tube M2 are both set to be driven by high voltage, and then the first conducting terminal and the second conducting terminal of the switch tube are conducted only when the control signal connected to the control terminal of the switch tube is in a high level state; if the first level signal is in high level state, the second level signal is in low level state, Y＝1,

At this time, the first driving signal is in a high level state, the second driving signal is in a low level state, the first switch tube M1 is turned on, and the second switch tube M2 is turned off; therefore, in the present embodiment, the level state of the control signal of each switching tube can be obtained through the logic operation between the signals, so as to ensure that each switching tube in the switching module 101 is in a safe and stable control state, the on/off of the first switching tube M1 and the second switching tube M2 has a more flexible control mode, the response speed is faster, the voltage output through the switching module 101 can meet the requirement of voltage digital conversion, the digital conversion accuracy of the control circuit 10 of the voltage digital converter in the present embodiment for the voltage analog quantity is ensured, and the control circuit 10 of the voltage digital converter has a higher control performance.

As an alternative embodiment, the energy storage module 102 includes: a first capacitance C1; wherein, a first end of the first capacitor C1 is connected to the switch module 101, and a second end of the first capacitor C1 is connected to the modulation module 103.

The first capacitor C1 has an energy storage function, when the switch module 101 has different on-state or off-state stages, the first capacitor C1 realizes charging operation or discharging operation according to the reference voltage Vref and the common mode voltage Vcom, and the first capacitor C1 can realize storage and release of charges, in the process, the first capacitor C1 performs charge conversion through a charging and discharging mode, a one-to-one correspondence relationship exists between the voltage accessed by the control circuit 10 of the voltage-to-digital converter and the charge variation of the first capacitor C1, so that the specific amplitude of the reference voltage Vref can be accurately obtained according to the charges output by the first capacitor C1; therefore, the energy storage module 102 in this embodiment has a relatively simplified circuit structure, and the accuracy of the charge in the transmission process can be changed by using the first capacitor C1, thereby avoiding a relatively large loss of the voltage in the conversion process; the energy storage module 102 can perform a voltage conversion function on the reference voltage Vref and the common mode voltage Vcom, so that the analog-to-digital conversion efficiency of the control circuit 10 of the voltage-to-digital converter is improved, the internal circuit structure of the control circuit 10 of the voltage-to-digital converter is simplified, and the conversion precision of the digital signal is higher.

As an alternative embodiment, referring to fig. 3, the switching signal includes a first switching signal and a second switching signal; the first switch signal and the second switch signal respectively contain corresponding circuit on-off control information, and in this embodiment, different circuits are respectively in corresponding on-off states through the first switch signal and the second switch signal, which is beneficial to improving the control precision and accuracy of the modulation module 103.

The switching unit 1031 includes: a variable resistor Rs, a third switching tube M3 and a fourth switching tube M4; a first conducting terminal of the third switching tube M3 is connected to the common mode voltage Vcom, a second conducting terminal of the third switching tube M3 and a first terminal of the variable resistor Rs are connected to the energy storage module 102 in common, a second terminal of the variable resistor Rs is connected to a first conducting terminal of the fourth switching tube M4, and a second conducting terminal of the fourth switching tube M4 is connected to the zero-crossing unit 1032.

When the energy storage module 102 outputs the charge to the switch unit 1031, since the resistance of the variable resistor Rs itself may change correspondingly, and the variable resistor Rs may play a role in limiting current and consuming power, the amount of charge transmitted in the control circuit 10 of the voltage-to-digital converter may be changed in time through the variable resistor Rs, so that the zero-crossing unit 1032 may completely receive the rated charge, and the power output by the switch unit 1031 may provide a bias current/voltage for the zero-crossing unit 1032, thereby ensuring the voltage-to-digital conversion stability and safety of the digital converter 10, and the control circuit 10 of the voltage-to-digital converter in this embodiment has a wider application range.

The control end of the third switching tube M3 is connected to the first switching signal, and the third switching tube M3 is turned on or off according to the level state of the first switching signal; for example, when the first switching signal is in the first level state, the third switching tube M3 is turned on, and when the first switching signal is in the second level state, the third switching tube M3 is turned off; the control end of the fourth switching tube M4 is connected to the second switching signal, and the fourth switching tube M4 is turned on or off according to the level state of the second switching signal; for example, when the second switching signal is in the first level state, the fourth switching tube M4 is turned on, and when the second switching signal is in the second level state, the fourth switching tube M4 is turned off; therefore, the third switching tube M3 and the fourth switching tube M4 in this embodiment have a more flexible on-off control manner.

Optionally, the third switching tube M3 is an MOS tube or an audion, and the fourth switching tube M4 is an MOS tube or an audion, and the switching unit 1031 in this embodiment has a relatively compatible circuit structure.

Optionally, the phases of the first switching signal and the second switching signal are staggered; the third switching tube M3 and the fourth switching tube M4 may be in different on or off states, respectively, and the switching unit 1031 may be turned on or off according to the actual requirements of the technician, so that the controllability is very strong; the charge amount can be changed in time through the variable resistor Rs, so that the reference voltage Vref and the common-mode voltage Vcom have higher adjustability, the control circuit 10 of the voltage-to-digital converter can adjust the charge amount in real time, and the running voltage in the control circuit 10 of the voltage-to-digital converter is prevented from exceeding a safe amplitude value; the input voltage variation condition of the control circuit 10 of the voltage digital converter can be obtained more accurately through the electric charges output by the switch unit 1031, the control circuit 10 of the voltage digital converter realizes a more accurate voltage digital conversion function according to the electric charges output by the switch unit 1031, and the digital coding signal has higher resolution; therefore, the switch unit 1031 in this embodiment has a flexible circuit structure, so that the stability and safety of the electric charge transfer in the switch unit 1031 are improved, the control circuit 10 of the voltage digital converter can maintain a stable operating state, and the control circuit 10 of the voltage digital converter has a wider application range.

As an alternative implementation, referring to fig. 3, the quantizer 104 includes: the circuit comprises a first voltage input end, a second voltage input end, a control end and a digital signal output end;

wherein, the first voltage input end of the quantizer 104 is connected to the zero-crossing unit 1032, and the integrated voltage can be output to the quantizer 104 through the zero-crossing unit 1032; a second voltage input terminal of the quantizer 104 is connected to the common mode voltage Vcom, a control terminal of the quantizer 104 is connected to the second control signal C2, and the quantizer 104 operates or stops according to a level state of the second control signal C2; for example, when the second control signal C2 is at the first level, the quantizer 104 is in the on state, and when the second control signal C2 is at the second level, the quantizer 104 is in the off state; therefore, the present embodiment can change the voltage-to-digital conversion function of the quantizer 104 in time by the second control signal C2, so as to improve the voltage-to-digital conversion efficiency and the controllability of the control circuit 103 of the voltage-to-digital converter.

When the quantizer 104 is in operation, the quantizer 104 performs a differential operation on the integrated voltage and the common-mode voltage to generate the digital encoded signal, and a digital signal output terminal of the quantizer outputs the digital encoded signal; when the quantizer 104 is stopped, the quantizer 104 cannot perform a digital conversion function for the voltage, and the control circuit 10 of the voltage-to-digital converter cannot output a digital code signal.

The phase of the second control signal C2 is the same as the phase of the second switching signal.

In this embodiment, the voltage-to-digital conversion function of the quantizer 104 has a correlation with the on-off state of the switch unit 1031, when the switch unit 1031 adjusts the charge amount, the integrated voltage output by the zero-crossing unit 1032 changes correspondingly, and the change condition of the integrated voltage can be completely consistent with the change condition of the reference voltage Vref, and the quantizer 104 can obtain corresponding voltage change information and perform analog-to-digital conversion according to the voltage change information; the common mode voltage Vcom can provide voltage reference information, the fluctuation condition of the integral voltage can be obtained according to the amplitude difference between the integral voltage and the common mode voltage Vcom, after differential operation is carried out on the amplitude difference, the integral voltage is divided into different voltage amplitude intervals, and the integral voltage of each interval corresponds to a specific numerical value so as to output a corresponding digital coding signal; therefore, the quantizer 104 in the present embodiment can distinguish the charge amount into different discrete values in real time according to the actual needs of the technician, so as to realize the voltage-to-digital conversion function of the control circuit 104 of the voltage-to-digital converter; therefore, the control circuit 10 of the voltage-to-digital converter in the embodiment has better overall coordination control performance, reduces the analog-to-digital conversion steps in the embodiment, and has lower generation cost of digital coding signals.

As an alternative embodiment, referring to fig. 3, the zero-crossing unit 1032 includes: the comparator Cmp, the integrating capacitor Cf, the fifth switching tube M5 and the constant current source If.

A first input end of the comparator Cmp is connected to the common-mode voltage Vcom, a second input end of the comparator Cmp and a first end of the integrating capacitor Cf are commonly connected to the switch unit 1031, a second end of the integrating capacitor Cf, a first conducting end of the fifth switching tube M5, an output end of the comparator Cmp and a first end of the constant current source If are commonly connected to the quantizer 104, and a second end of the constant current source If is connected to a ground GND; the constant current source If can output a stable direct current, and the voltage output by the integrating capacitor Cf can be adaptively adjusted by the constant current source If, so that the zero-cross unit 1032 can realize stable and safe feedback and adjustment effects on the charge.

It should be noted that the first input terminal of the comparator Cmp in this embodiment is a positive phase input terminal or an inverted phase input terminal, which is not limited to this; if the first input terminal of the comparator Cmp is a positive-phase input terminal, the second input terminal of the comparator Cmp is an inverted-phase input terminal.

A second end of the fifth switching tube M5 is connected to a first direct current power supply VCC 1; a control end of the fifth switching tube M5 is connected to a third driving signal, and the fifth switching tube M5 is turned on or off according to a level state of the third driving signal; for example, if the third driving signal is in the first level state, the five switching tube M5 is turned on, and if the third driving signal is in the second level state, the five switching tube M5 is turned off; therefore, the fifth switch tube M5 in this embodiment has a more flexible control method.

Optionally, the first dc power supply VCC1 is a +3V to +5V dc power supply, and the dc power supply VCC1 can output the dc power to the integrating capacitor Cf, so that the zero-crossing unit 1032 can be ensured to realize a stable power integration process through the dc power supply, and the modulation module 103 realizes a self-adaptive feedback modulation function for the power.

In the specific circuit structure of the zero-cross unit 1032 shown in fig. 3, by using the power integration function of the integrating capacitor Cf, when the switching unit 1031 outputs the adjusted charges to the zero-cross unit 1032, there is a charge difference between the charges of the first input terminal and the second input terminal of the comparator Cmp, and the comparator Cmp amplifies the charge difference to output a voltage, so as to implement the power digital switching function; in the process that the integral capacitor Cf is connected with the charge, the voltages at two ends of the integral capacitor Cf cannot change suddenly, the integral capacitor Cf has an integral effect on the voltage output by the comparator Cmp, the amplitude of the voltage output by the comparator Cmp can be slowly adjusted through the integral effect, and the voltage output by the comparator Cmp is prevented from having errors; in this embodiment, the amplitude of the voltage at the output end of the comparator Cmp and the amplitude of the reference voltage Vref can be kept completely consistent, the zero-crossing unit 1032 can perform accurate charge transfer, the digital conversion precision of the control circuit 10 of the voltage-to-digital converter on the voltage is guaranteed, the error in the charge conversion process can be adaptively adjusted through the integrating capacitor Cf, and the anti-aliasing performance and the resolution of the modulation module 103 are improved; therefore, the zero-crossing unit 1032 realizes equivalent transfer of charges by using the comparator Cmp, the integrating capacitor Cf and the constant current source If, converts the charges into an integrated voltage which can be directly quantized and calculated, so as to complete delta sigma modulation feedback of the charges, the control circuit 10 of the voltage digital converter performs faster and more accurate conversion modulation on the charges, the signal-to-noise ratio in the voltage digital conversion process is improved, the zero-crossing unit 1032 has higher adjustability on the integrating and amplifying operations of the charges, the control circuit 10 which can drive the voltage digital converter by the integrated voltage can accurately realize the analog-to-digital conversion function, and the power consumption of the digital converter 10 is reduced, so that the digital converter 10 has a wider application range, and the compatibility and the practicability of the digital converter 10 are guaranteed.

To better illustrate the operation principle of the control circuit 10 of the voltage-to-digital converter in the above embodiment, the following description will be made through a series of comparative experiments to illustrate the principle of the control circuit 10 of the voltage-to-digital converter for voltage analog-to-digital conversion, and the excellent performance of the control circuit 10 of the voltage-to-digital converter for voltage-to-digital conversion, specifically as follows:

to better illustrate the performance of the control circuit 10 of the voltage-to-digital converter, fig. 4 shows a comparative experimental reference circuit, in which the control circuit 40 of the voltage-to-digital converter in fig. 4 differs from the control circuit 10 of the voltage-to-digital converter in fig. 3 mainly in that: the zero-crossing unit 4032 in fig. 4 replaces the comparator Cmp in fig. 3 with a transconductance amplifier OTA capable of differentiating the voltage across its input to convert it into an output current, and the control circuit 40 of the voltage-to-digital converter generates a discrete digital code signal according to the current; the differences between the control circuit 10 of the voltage-to-digital converter in fig. 3 and the control circuit 40 of the voltage-to-digital converter in fig. 4 can be summarized as: the control circuit 10 of the voltage digitizer in fig. 3 uses the comparator Cmp + the integrating capacitor Cf to realize the charge conversion, and the control circuit 40 of the voltage digitizer in fig. 4 uses the transconductance amplifier OTA + the integrating capacitor CS2 to realize the charge conversion.

It should be noted that the control circuit 40 of the voltage-to-digital converter in fig. 4 is merely used as a reference for comparison of the control circuit 10 of the voltage-to-digital converter in fig. 3, and is not meant to constitute the conventional technology of the present application.

The charge conversion process of the control circuit 40 of the voltage-to-digital converter in fig. 4 will be analyzed as follows:

the charge quantity on the capacitor CS1 depends on the on or off time of both the switch tube MS1 and the switch tube MS 2; wherein the level state of the control signal of the switch tube MS1 and the level state of the control signal of the switch tube MS2 can refer to the above equation (1) and equation (2), respectively; exemplarily, fig. 5 shows a waveform curve of each signal, wherein in fig. 5, each letter represents a physical meaning:

φ_1d、φ_2dphi corresponds to the first level signal and the second level signal in the above formulas (1) and (2)₁Represents a first switching signal phi₂Represents a second switching signal phi_preRepresents a third drive signal phi_sControl signal, V, representing a constant current source₀Representing the integral voltage, V_zRepresenting the voltage at the first input of the transconductance amplifier OTA (or the voltage at the first input of the comparator Cmp); it should be noted that the control circuit 10 of the voltage-to-digital converter in fig. 3 and the control circuit 40 of the voltage-to-digital converter in fig. 4 have the same control signal timing, so that the waveform curves of the signals in fig. 5 can be applied to both fig. 3 and fig. 4.

During each period of the signal, the charge on the capacitor CS1 is transferred to the capacitor CS2, and when Y is 1 or 0, the amount of transferred charge is as follows according to the above equations (1) and (2): (V)_ref-V_cm)·CS₁Or (V)_cm-V_ref)·CS₁Wherein the CS₁For the capacitance value of capacitor CS1, the transconductance amplifier OTA is positioned in the sampled delta-sigma modulation feedback loop and quantizer 404 is added to update Y to a new value at the falling edge of Φ 2, forcing the average value Q of CS1_zIs close to zero; thus, the following equation exists:

Q_z＝(V_ref-V_cm)·CS₁·N(1)+(V_cm-V_ref)·CS₁·N(0)＝0 (3)；

where N (1) and N (0) respectively count 1 or 0 in the single-bit output stream Y, and the total number N of the single-bit output stream Y is N (1) + N (0). The average value of Y can be given by:

since the virtual ground condition exists between the first input terminal and the second input terminal of the transconductance amplifier OTA when the node voltage of the first input terminal of the transconductance amplifier OTA is obtained, the virtual ground condition exists in the integration stage (phi)₂Is high level),the integration voltage and the node voltage of the first input terminal of the transconductance amplifier OTA are both exponentially changed to a stable value, so that the control circuit 40 driving the voltage digitizer can stably and safely output the digitally encoded signal.

As for the operation principle of the above-described digitizer 40, the operation principle of the digitizer 10 in fig. 3 is analyzed as follows: firstly, V is firstly_zSet to be greater than, then V₀Will be in a short preset time period phi_prePulled up to a first dc power supply VCC1, after which the integrating capacitor Cf and the constant current source If are switched on to build the integrator, as shown in fig. 5, a virtual ground state (V) will exist at the first input terminal and the second input terminal of the comparator Cmp_z＝V_cm) And turning off the constant current source If, where t in fig. 5_dA voltage digital conversion delay time for the digitizer 40; then the same virtual ground condition exists for both the comparator Cmp in fig. 3 and the transconductance amplifier OTA in fig. 4, and all the charge on the first capacitor C1 has been transferred to the integrating capacitor Cf, and hence the Y_aveShould be identical to Y in the control circuit 40 of the voltage-to-digital converter in FIG. 4_aveAre correspondingly the same (i.e. Y)_ave1/2); the digital converter 10 in fig. 3 stably converts the charge variation amount into a discrete digital code signal.

To better illustrate the transfer and variation of the charge in the control circuit 10 of the voltage-to-digital converter of fig. 3, fig. 6 shows an equivalent circuit analysis diagram of the control circuit 10 of the voltage-to-digital converter of fig. 3, and the circuit diagram of fig. 6 also has 4 parasitic capacitances: c_px、C_pw、C_pz、C_po(ii) a The parasitic capacitance is generated due to mutual capacitance among a plurality of capacitances, and the parasitic capacitance can store part of charges in the working process of the circuit and consume some electric energy, so that charge calculation errors exist in the charge transfer process in the control circuit 10 of the voltage-to-digital converter; therefore, in order to analyze the voltage-to-digital conversion process of the control circuit 10 of the voltage-to-digital converter more accurately, the charge transfer process is analyzed in conjunction with fig. 6 as follows:

in FIG. 6, the results are comparedThe integrator cmp, the integrating capacitor Cf and the constant current source If form an integrator, and in the process of Δ Σ modulation feedback of the charge by the zero-crossing unit 1032, the constant current source If is used for stabilizing the output voltage (integrated voltage) of the integrator and changing the bias current in the integrator, so that the variation of the integrated voltage output by the zero-crossing unit 1032 can be completely consistent with the variation of the output charge amount of the switching unit 1031; wherein fig. 7 shows the waveform curves of the respective control signals and the respective node voltages provided by the present embodiment, in conjunction with fig. 5 and fig. 7; where Vo in FIG. 7 is the voltage at node O, V_zIs the voltage of node Z, V_wIs the voltage of node W, V_XThe specific positions of the node O, the node Z, the node W and the node X are shown in fig. 7, for example, the node X and the node W are located at two ends of the variable resistor Rs; referring to the charge transfer analysis process of FIGS. 3 and 4 above; in FIG. 6, V is when the first and second inputs of the comparator Cmp are virtually grounded_z＝V_cm，V_X＝V_cm+V_Rs(see FIG. 7); the charge output from the first capacitor C1 is: (V)_ref-V_cm+V_Rs)·C₁Or (V)_cm-V_ref+V_Rs)·C₁Wherein said C is₁The capacitance value of the first capacitor C1 is represented by formula (1) or formula (2), where Y is 1 or 0; therefore, according to the charge-discharge balance principle of the first capacitor C1, the following formula can be derived:

Q_z＝(V_ref-V_cm+V_Rs)·C₁·N(1)+(V_cm-V_ref+V_Rs)·C₁·N(0)＝0 (5)

then Y is_aveAccording to the following formula:

comparing equation (5) above with equation (6) above, at addition of Rs, there is:

in the above formula (7), the Δ Y_aveIs Y_aveThen, in combination with the above equations (5), (6) and (7), Y in the control circuit 10 of the voltage-to-digital converter can be used_aveThe amount of change in the variable resistance Rs is observed; when 0 is present<Y_ave<1 andsetting the parameter after voltage digital conversion to be 1, V_refAnd V_cmMust be adjusted by a variable resistor Rs, if the resistance of the variable resistor Rs is regarded as a nominal resistor R_oAnd a variable resistance range Δ R_sA combination of the two, then V_refAnd V_cmThe nominal resistance R must be used_oAnd a variable resistance range Δ R_sIs optimized, wherein R_s＝R_o+ΔR_s。

In order to simplify the process of analyzing the transfer of the charge, fig. 8 shows the equivalent circuit structure of fig. 6 provided in the present embodiment, wherein the process of transferring the charge in the first capacitor C1 is shown in fig. 8; as shown in fig. 8, in an ideal state of the constant current source If (i.e. the constant current source If has no internal resistance), referring to fig. 8, all the current I from the constant current source If will flow through the variable resistor Rs, i.e. I ═ I_RsIn which I_RsTo flow the current of the variable resistor Rs, but due to some part of the current I will be parasitic capacitance C_px、 C_pw、C_pzAnd C_poShunting, i.e. I ≠ I_RsLet I assume_RsBeing constant in the near minute time interval dt, the integrating capacitance Cf has an integrating effect on the charge, and the following equation exists:

dVx＝dVw＝dVz (8)

the conservation of charge law for node X, node W and node Z navigation can be expressed by the following equation:

dVx·(C_s+C_px)+dV_w·C_pw+dV_z·C_pz+(dV_z-dV_o)·C_f＝0 (9)

binding of I and I_RsThe following formula exists:

I·dt＝dV_o·C_po+(dV_o-dV_z)·C_f(10)

I_Rs·dt＝dV_X·(C₁+C_px) (11)

thus, by combining the above formulae (8) to (11), I can be obtained_RsRatio to I:

from the above formula (12), I_RsRegardless of the ratio of I and the variable resistance Rs, C is measured during the charge conversion and measurement by the control circuit 10 of the voltage-to-digital converter₁And C_fAnd these parasitic capacitances C_px、C_pw、C_pzAnd C_poThe capacitance value of (b) is kept constant, so that when the variable resistor Rs changes, the non-linear change of the integral voltage is not caused, and the modulation module 103 can perform stable modulation on the charge so as to improve the precision of charge transfer.

The equivalent circuit structure in fig. 8 is ideal, however, in practical application, the constant current source If has the equivalent internal resistance R_cEquivalent internal resistance R_cMay affect the current biasing process of the zero crossing unit 1032; fig. 9 shows another equivalent circuit structure of the control circuit 10 of the voltage-to-digital converter in fig. 6 provided by the present embodiment, and compared with the equivalent circuit structure in fig. 8, the constant current source If in fig. 9 also has an equivalent internal resistance R_c(ii) a In fig. 9, the current I output by the constant current source If is kept constant in each cycle; however, there is an internal resistance R at the actual constant source If_cThis results in a varying current I [ n ]]：

I[n]＝I_C+I_R[n]＝I_C+V_o[n]/R_C(13)

Wherein, referring to FIG. 9, the equivalent resistance R_cIn parallel with the constant current source If, in the above equation (13),I_Cis the current flowing in an ideal current source, I_R[n]Is flowing into the internal resistance R_cOf the current of (1), the current of (I [ n ]) of (1)]Will change the voltage drop by V_Rs[n]＝I[n]·R_SThen the varying current I [ n ]]Will make the variable resistance R_SThere are some errors in the voltage measurement process that reduce the accuracy of the charge transfer calculation.

The output voltage (integration voltage) V of the integrator as a result of the Δ Σ modulation feedback_oShould relate to V_cmIs symmetrical with V_cmWith a corresponding wave curve, then I [ n ]]Is ═ I + DeltaI and V_oKeep consistent, assuming:

ΔI[n]＝(V_o[n]-V_cm)/R_c(15)

in combination with the above equations (5), (14) and (15), the following equations can be obtained:

in the above formula (16), N is an integer greater than 1; if the internal resistance R is_cIs infinite, e.g. in an ideal current source, substituting equation (16) into equation (5) above, then this part of equation (16)

The representation is the input reference noise caused by non-ideal current sources.

In addition, the method can be used for producing a composite material

Can be viewed as a random process with a uniformly modified density function; the input reference noise error power can therefore be calculated by the following equation:

wherein,

as can be seen from equation (17), the internal resistance Rs of the constant current source is negligible and inconsequential for the error caused by the charge transfer process of the integrator, and the control circuit 10 of the voltage digital converter in this embodiment implements the Δ Σ modulation feedback function with high precision for the charge.

Referring to fig. 7, the integral voltage V output by the integrator_oAt phi₂Fig. 10 shows the integrated voltage V provided by the present embodiment at the end of the active level state_oWith reference to fig. 10, for a constant current source If, the additional charge Δ V_o＝I·t_dDischarging to ground to generate an overshoot voltage Δ V_oAnd Δ V_ZOn node O and node Z, respectively; in addition, the error charge Q on the integration node Z due to the delay time of the integration capacitance Cf_err,zdIndependent of the variable resistance Rs; then equation (5) above can be modified to the following form:

Q_z,zd＝(V_ref-V_cm+V_Rs)·C₁·N(1)+(V_cm-V_ref+V_Rs)·C₁·N(0)+N·Q_err,zd＝0 (18)

according to the above equation (18), the charge offset error of the integrator in the control circuit 10 of the voltage-to-digital converter due to the delay time is Y_err,zdThus said Y_err,zdThe following formula may be given:

from the above equation (19), the charge offset error Y in the control circuit 10 of the voltage-to-digital converter_err,zdThe quantizer 104 can perform accurate digital conversion process on the integrated voltage and eliminate the integrated electricity in real time after the integrator integrates the charge, compares and amplifies the charge and outputs the integrated voltage without being interfered by the variable resistor RsCharge offset error in voltage Y_err,zdAnd detection errors caused in the charge transfer process are reduced.

Similar to the above-mentioned situation where the integrating capacitor Cf has a delay time and thus causes a charge offset error, and the like, referring to fig. 9, there is a corresponding voltage overshoot at the node O and the node Z, and therefore the following formula is satisfied:

Q_err,zo＝V_off·(C₁+C_pX+C_pw) (20)

in the above formula (20), said V_offRepresenting a bias voltage, Q, of said integrating capacitor Cf_err,zdRepresents the bias charge of the integrating capacitor Cf, so that the bias charge of the integrating capacitor Cf is independent of the resistance value of the variable resistor Rs; then the charge offset error Y of node Z_ave,zoCan be calculated by the following formula:

in the above equation (21), the delay time of the charge at the node Z only causes the offset error of the charge output by the integrator, and in combination with the above equation (21) and equation (19), the offset error charges at the node O and the node Z in the control circuit 10 of the voltage-to-digital converter in this embodiment are independent of the resistance of the variable resistor Rs, and do not interfere with the voltage-to-digital conversion process of the quantizer 104.

Therefore, according to the above comparative experiment, the working principle of the control circuit 10 of the voltage-to-digital converter in the embodiment of the present invention can realize the automatic adjustment and integration functions for the charges through the comparator Cmp and the integration capacitor Cf, so as to prevent the charges from deviating during the transmission process; when the energy storage module 102 transmits the charges to the modulation module 103, the modulation module 103 performs adaptive transfer and conversion on the charges, a stable integral voltage can be generated after Δ Σ modulation feedback is performed on the charges, and the variation of the integral voltage is completely consistent with that of the charges, so that the accuracy of digital conversion on the voltages is improved; the electric energy output by the energy storage module 102 can provide bias electric energy for the modulation module 103, so that the function of the electric energy is reduced, and the control circuit 10 of the voltage digital converter has higher voltage digital conversion efficiency; therefore, the control circuit 10 of the voltage-to-digital converter in the embodiment can avoid charge interference errors generated in the transmission process of charges, improve the stability and reliability of delta sigma modulation feedback of the voltage, accurately distinguish the control circuit 10 of the voltage-to-digital converter into discrete digital coding signals according to the amplitude of the input voltage, improve the precision and resolution of voltage-to-digital conversion in the control circuit 10 of the voltage-to-digital converter, and have higher compatibility and wider application range; the problems that a control circuit of the voltage digital converter in the traditional technical scheme has larger total power consumption and voltage digital conversion has larger errors are effectively solved.

Fig. 11 shows a module structure of the resistance sensor reading circuit 110 provided in this embodiment, where the resistance sensor reading circuit 110 can acquire a resistance variation amount of the resistance sensor itself, and convert the resistance variation amount into a recognizable digital mode according to the resistance variation amount, so that a technician can directly obtain a resistance variation condition of the resistance sensor through a digital quantity, thereby improving the acquisition precision and sampling accuracy of the resistance value of the resistance sensor itself; as shown in fig. 11, the resistance sensor readout circuit 110 includes: a current source 1101, a resistance sensor 1102, a voltage converter 1103 and a control circuit 10 of a voltage to digital converter as described above.

The current source 1101 outputs a drive current.

Wherein the driving current is capable of providing driving power by which the resistance sensor readout circuit 10 is provided with measurement power; when the resistance sensor reading circuit 10 is connected to the driving current, the resistance sensor reading circuit 10 can be in a stable working state, reliability and stability of resistance of the resistance sensor are guaranteed, and the resistance sensor reading circuit 10 has a higher application range and a higher practical value.

The resistance sensor 1102 is connected to the current source 1101 and configured to change its resistance value according to an external disturbance amount.

Optionally, the external disturbance amount includes: the resistance sensor has higher sensitivity to the change of the external environment parameters, so that the resistance value of the resistance sensor can be correspondingly changed when the external environment parameters are changed; illustratively, when the temperature of the outside rises, the resistance value of the resistance sensor 1102 rises; when the outside temperature decreases, the resistance value of the resistance sensor 1102 decreases; therefore, the resistance variation of the resistance sensor in this embodiment has a one-to-one correspondence relationship with the external disturbance amount.

In this embodiment, the resistance sensor 1102 can sense the change of various non-electrical physical quantities in the external environment, and convert the change of various non-electrical physical quantities into the change of electrical physical quantities, so as to realize accurate measurement of the resistance value of the resistance sensor 1102; the resistance sensor 1102 can accurately detect various external disturbance quantities; the change conditions of various physical quantities in the external environment can be accurately obtained according to the variation of the resistance value of the resistance sensor 1102, and the change conditions of various physical quantities in the external environment can be monitored in real time through the resistance value of the resistance sensor 1102.

The voltage converter 1103 is connected to the resistance sensor 1102, and is configured to collect a variation of an operating current of the resistance sensor 1102 and convert the variation of the operating current into a reference voltage.

The current source 1101 outputs a driving current to the resistance sensor 1102, and when the resistance value of the resistance sensor 1102 changes, the operating current of the resistance sensor 1102 also changes, and a one-to-one correspondence relationship exists between the operating current variation of the resistance sensor 1102 and the resistance variation of the resistance sensor 1102; when the operating current of the resistance sensor 1102 changes, the voltage converter 1103 can collect the variation of the operating current of the resistance sensor 1102 and convert the variation of the operating current into a reference voltage, so as to accurately measure the resistance value of the resistance sensor 1102; therefore, the voltage converter 1103 in this embodiment can implement a current-voltage real-time conversion function, the magnitude of the resistance sensor 1102 itself can be accurately obtained by referring to the amplitude of the voltage, the sampling precision and the current conversion rate of the resistance sensor 1102 itself are improved, and the resistance sensor reading circuit 10 has a higher application range and universality.

It should be noted that, in the present embodiment, the voltage converter 1103 may be implemented by using a circuit structure in the conventional technology, which is not limited herein; illustratively, the voltage converter 103 includes: after the comparator is connected to the operating current of the resistance sensor 1102, the comparator can output a reference voltage matched with the current quantity by using the current comparing and amplifying functions of the comparator, the comparator can realize an accurate conversion function on the electric energy, the voltage converter 1103 has high voltage conversion precision, and the resistance value of the resistance sensor 1102 can be accurately obtained according to the reference voltage; therefore, the voltage converter 1103 has a compatible circuit structure, the manufacturing cost is extremely low, and the circuit manufacturing cost and the application cost of the voltage converter 1103 are effectively reduced, so that the resistance sensor reading circuit 110 can be applied to various external environments to realize accurate sampling of various non-electrical physical quantities.

The control circuit 10 of the voltage-to-digital converter is connected to the voltage converter 1103, and the control circuit 10 of the voltage-to-digital converter is connected to the reference voltage and converts the reference voltage into a digital code signal; when the control circuit 10 of the voltage-to-digital converter converts the reference voltage into a digital quantity, the specific amplitude of the reference voltage can be accurately obtained according to the digital quantity; the control circuit 10 of the voltage digital converter can realize an accurate analog-to-digital conversion function on the reference voltage, and the digital signal after digital processing can be identified and analyzed by an external mobile terminal, so that the amplitude of the reference voltage of the resistance sensor 1102 is obtained; further, the self resistance value of the resistance sensor 1102 is calculated according to the reference voltage of the resistance sensor 1102, so that the high-precision sampling and voltage fast conversion functions of the self resistance value of the resistance sensor 1102 are realized; the resistive sensor readout circuit 1102 in this embodiment has a high range of applicability.

With reference to the embodiments of fig. 1 to 10, the resistance sensor 1102 can accurately obtain the variation of the interference in the external environment, the voltage converter 1103 acquires the variation of the operating current of the resistance sensor 1102 to obtain the corresponding reference voltage, and the control circuit 10 of the voltage-to-digital converter performs mode conversion on the reference voltage, so that a technician can more intuitively obtain the variation of the resistance value of the resistance sensor 1102; because the control circuit 10 of the voltage digital converter has lower power consumption, and the control circuit 10 of the voltage digital converter has extremely high rotating speed efficiency for the reference voltage, the converted digital signal has extremely high resolution and precision; then, the control circuit 10 of the voltage-to-digital converter performs delta-sigma modulation on the analog voltage to obtain a signal in a digital mode, and various external mobile terminals can recognize and process the digital signal to obtain the resistance value of the corresponding resistance sensor 1102, so that technicians can monitor the external physical parameter change conditions of various non-electric quantities in real time through the control circuit 10 of the voltage-to-digital converter, thereby bringing good use experience to users; therefore, when the control circuit 10 of the voltage digital converter is applied to the resistance sensor reading circuit 110 in this embodiment, the resistance sensor reading circuit 110 accurately samples various physical quantities in the external environment by using the resistance sensor 1102, and the variation of the voltage of the resistance sensor 1102 itself is used to obtain the variation of the various physical quantities in the external environment, the control circuit 10 of the voltage digital converter generates a corresponding digital signal according to the reference voltage, and the specific amplitude of the resistance value of the resistance sensor 1102 itself can be accurately obtained according to the digital signal; therefore, the resistance sensor reading circuit 110 in this embodiment realizes an analog-to-digital conversion function for the voltage of the resistance sensor 1102, and has a high signal-to-noise ratio in the process of performing voltage-to-digital conversion on analog quantity, the resistance sensor reading circuit 110 can accurately sample various physical quantities in the external environment, the operation is simple and convenient, the circuit structure is simple, and further the resistance sensor reading circuit 110 can be applied to various different industrial technical fields, and the compatibility is extremely strong; the problems that in the prior art, a resistance sensor reading circuit is low in resistance sampling precision, in the process of analog-to-digital conversion of analog quantity, the precision and resolution of digital signals obtained through conversion are low, large electric energy consumption is needed, various physical quantities in the external environment cannot be accurately sampled through the conventional resistance sensor reading circuit, compatibility is low, and universal application is difficult are effectively solved.

Various embodiments are described herein for various devices, circuits, apparatuses, systems, and/or methods. Numerous specific details are set forth in order to provide a thorough understanding of the overall structure, function, manufacture, and use of the embodiments as described in the specification and illustrated in the accompanying drawings. However, it will be understood by those skilled in the art that the embodiments may be practiced without such specific details. In other instances, well-known operations, components and elements have been described in detail so as not to obscure the embodiments in the description. It will be appreciated by those of ordinary skill in the art that the embodiments herein and shown are non-limiting examples, and thus, it can be appreciated that the specific structural and functional details disclosed herein may be representative and do not necessarily limit the scope of the embodiments.

Reference throughout the specification to "various embodiments," "in an embodiment," "one embodiment," or "an embodiment," etc., means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, appearances of the phrases "in various embodiments," "in some embodiments," "in one embodiment," or "in an embodiment," or the like, in places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. Thus, a particular feature, structure, or characteristic illustrated or described in connection with one embodiment may be combined, in whole or in part, with features, structures, or characteristics of one or more other embodiments without presuming that such combination is not an illogical or functional limitation. Any directional references (e.g., plus, minus, upper, lower, upward, downward, left, right, leftward, rightward, top, bottom, above …, below …, vertical, horizontal, clockwise, and counterclockwise) are used for identification purposes to aid the reader's understanding of the present disclosure, and do not create limitations, particularly as to the position, orientation, or use of the embodiments.

Although certain embodiments have been described above with a certain degree of particularity, those skilled in the art could make numerous alterations to the disclosed embodiments without departing from the scope of this disclosure. Joinder references (e.g., attached, coupled, connected, and the like) are to be construed broadly and may include intermediate members between a connection of elements and relative movement between elements. Thus, connection references do not necessarily imply that two elements are directly connected/coupled and in a fixed relationship to each other. The use of "for example" throughout this specification should be interpreted broadly and used to provide non-limiting examples of embodiments of the disclosure, and the disclosure is not limited to such examples. It is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative only and not limiting. Changes in detail or structure may be made without departing from the disclosure.

The above description is only exemplary of the present invention and should not be construed as limiting the present invention, and any modifications, equivalents and improvements made within the spirit and principles of the present invention are intended to be included within the scope of the present invention.

Claims

1. A control circuit for a voltage to digital converter, comprising:

the switching module is configured to switch in or switch off the reference voltage and/or the common mode voltage according to the level state of the first control signal;

the modulation module is connected with the energy storage module and is configured to output an integral voltage after delta sigma modulation feedback is carried out on the charge output by the energy storage module; and

2. The control circuit of a voltage-to-digital converter according to claim 1, wherein said switching module comprises: the first switch tube and the second switch tube; the first control signal includes: a first drive signal and a second drive signal;

3. The control circuit of the voltage-to-digital converter according to claim 2, wherein the level state of the first driving signal and the level state of the second driving signal satisfy the following condition:

4. The control circuit of the voltage-to-digital converter according to claim 1, wherein the energy storage module comprises: a first capacitor;

5. The control circuit of a voltage-to-digital converter according to claim 1, wherein said modulation module comprises:

6. The control circuit of the voltage-to-digital converter according to claim 5, wherein the switching signal comprises a first switching signal and a second switching signal;

7. The control circuit of claim 6, wherein the phases of the first switching signal and the second switching signal are interleaved.

8. The control circuit of the voltage-to-digital converter according to claim 6, wherein the quantizer comprises: the circuit comprises a first voltage input end, a second voltage input end, a control end and a digital signal output end;

9. The control circuit of the voltage-to-digital converter according to claim 5, wherein the zero-crossing unit comprises: the comparator, the integrating capacitor, the fifth switching tube and the constant current source;

10. A resistive sensor readout circuit, comprising:

a current source configured to output a drive current;

a control circuit of a voltage to digital converter as claimed in any one of claims 1 to 9, the control circuit of the voltage to digital converter being connected to the voltage converter, the control circuit of the voltage to digital converter being connected to the reference voltage and being converted into a digitally encoded signal.