Digital-to-analog conversion structure and control method

Abstract

The application relates to the field of electronic circuit devices, and provides a digital-to-analog conversion structure and a control method. The digital-to-analog conversion structure comprises a signal conversion module configured to receive a digital signal and output an adjusting signal based on the digital signal; a signal output module comprising: an impedance adjusting unit connected to the signal conversion module and configured to adjust an impedance value of the impedance adjusting unit based on the adjusting signal; and a signal generation unit connected to the impedance adjusting unit and configured to output an analog signal based on the impedance value of the impedance adjusting unit. The device properties of the impedance adjusting unit are changed with the change of the resistance value of the impedance adjusting unit with the adjusting signal, and the adjusting signal is generated corresponding to the digital signal, thereby avoiding the corresponding relationship between the digital signal and the circuit setting, continuously increasing the bit number of the digital signal to be converted, and improving the resolution of the digital-to-analog conversion structure.

Description

Technical Field

[0001] This application relates to the field of electronic circuit devices, specifically to a digital-to-analog conversion structure and control method. Background Technology

[0002] Digital-to-analog conversion is the process of converting discrete digital quantities into analog quantities that change over time. The circuit or device that performs this function is called a digital-to-analog conversion circuit, usually referred to as a digital-to-analog converter or DAC (Digital Analog Converter).

[0003] As an important component of electronic systems, digital-to-analog converters are mainly used in communication systems, data acquisition and measurement, audio and image processing.

[0004] However, digital-to-analog converters suffer from problems such as complex circuitry, large area, and difficulty in changing their sampling resolution once the structure is fixed. Summary of the Invention

[0005] The purpose of this application is to provide a digital-to-analog conversion structure and control method, which aims to improve the resolution of digital-to-analog conversion.

[0006] In a first aspect, this application provides a digital-to-analog conversion structure, comprising: a signal conversion module configured to: receive a digital signal and output an adjustment signal based on the digital signal; a signal output module comprising: an impedance adjustment unit connected to the signal conversion module and configured to: adjust the impedance value of the impedance adjustment unit based on the adjustment signal; and a signal generation unit connected to the impedance adjustment unit and configured to: output an analog signal based on the impedance value of the impedance adjustment unit.

[0007] In some embodiments, the adjustment signal includes adjustment pulses; the change in impedance value responds to a change in the number of adjustment pulses or a change in the duty cycle of the adjustment signal; if the change in impedance value responds to a change in the number of adjustment pulses, the signal conversion module includes a first pulse generation circuit configured to: receive the digital signal and generate the adjustment signal based on the digital signal, wherein the number of adjustment pulses in the adjustment signal is the number corresponding to the digital signal; if the change in impedance value responds to a change in the duty cycle of the adjustment signal, the signal conversion module includes a second pulse generation circuit configured to: receive the digital signal and generate the adjustment signal based on the digital signal, wherein the duty cycle of the adjustment signal is the duty cycle corresponding to the digital signal.

[0008] In some embodiments, the impedance value is linearly related to the number of adjustment pulses.

[0009] In some embodiments, the first end of the impedance adjustment unit is connected to the output end of the signal conversion module and the output end of the signal generation unit; the second end of the impedance adjustment unit is connected to the input end of the signal generation unit.

[0010] In some embodiments, the impedance adjustment unit includes a phase change memory unit or a resistive change memory unit.

[0011] In some embodiments, the signal generation unit is configured to: receive a reference current and output the analog signal based on the reference current and the impedance value of the impedance adjustment unit; the signal generation unit includes: an operational amplifier, with a positive input terminal for receiving the reference current and connected to a first terminal of the impedance adjustment unit, a negative input terminal grounded, and an output terminal for outputting the analog signal.

[0012] In some embodiments, the signal output module further includes a control unit configured to: receive a switching signal, control the impedance adjustment unit to acquire the adjustment signal based on the switching signal, or control the signal generation unit to output the analog signal.

[0013] In some embodiments, the control unit includes a control switch, a first selection terminal connected to the output terminal of the signal conversion module, a second selection terminal connected to the output terminal of the signal generation unit, and a control terminal connected to the impedance adjustment unit; the control switch is configured to: control the control terminal to electrically connect to the first selection terminal or the second selection terminal based on the switching signal; when the control switch controls the control terminal to electrically connect to the first selection terminal based on the switching signal, the impedance adjustment unit changes its impedance value in response to the adjustment signal; when the control switch controls the control terminal to electrically connect to the second selection terminal based on the switching signal, the signal generation unit outputs an analog signal based on the impedance value of the impedance adjustment unit.

[0014] Secondly, this application provides a control method applied to the digital-to-analog converter structure mentioned in the first aspect above, comprising: acquiring a digital signal and outputting an adjustment signal based on the digital signal; performing a write operation in response to the adjustment signal to adjust the impedance value of an impedance adjustment unit; and performing a read operation to output an analog signal based on the impedance value of the impedance adjustment unit.

[0015] In some embodiments, the write operation includes: a signal conversion module outputting an adjustment signal based on the digital signal, the adjustment signal including adjustment pulses, the number of adjustment pulses in the adjustment signal being the number corresponding to the digital signal; the impedance adjustment unit responding to the adjustment pulses in the adjustment signal and gradually changing the impedance value based on each adjustment pulse; the read operation includes: providing a reference current; and a signal generation unit outputting an analog signal based on the reference current and the impedance value of the impedance adjustment unit.

[0016] In some embodiments, the control method further includes: receiving a switching signal; and switching between the write operation and the read operation based on the switching signal.

[0017] The digital-to-analog converter structure provided in this application utilizes the device properties of the impedance adjustment unit to make the resistance value of the impedance adjustment unit change with the adjustment signal. The adjustment signal corresponds to the generation of a digital signal, avoiding the correspondence between the digital signal and the circuit settings. This allows the number of bits of the digital signal to be converted to be continuously increased, thereby improving the resolution of the digital-to-analog converter structure. Attached Figure Description

[0018] The technical solution and other beneficial effects of this application will become apparent from the following detailed description of specific embodiments in conjunction with the accompanying drawings.

[0019] Figure 1 This is a schematic diagram of a digital-to-analog converter circuit.

[0020] Figure 2 This is a schematic diagram of the module structure of the digital-to-analog conversion structure provided in some embodiments of this application;

[0021] Figure 3 This is a schematic diagram illustrating the principle of impedance value change based on the number of adjustment pulses in some embodiments of the impedance adjustment unit provided in this application;

[0022] Figure 4 This is a schematic diagram illustrating the principle of impedance value change based on pulse width of adjustment signal of impedance adjustment unit provided in some embodiments of this application;

[0023] Figure 5 These are schematic diagrams illustrating the specific structure of the digital-to-analog conversion structure provided in some embodiments of this application;

[0024] Figure 6 This is a schematic diagram of a digital-to-analog converter structure including a control unit provided in some embodiments of this application;

[0025] Figure 7 This is provided by some embodiments of this application. Figure 6 The timing diagram of each signal in the digital-to-analog converter structure is shown below.

[0026] Figure 8 This is a flowchart illustrating each step in the control method provided in some embodiments of this application;

[0027] Figure 9 This is a flowchart illustrating the steps of a control method including switching signal control provided in some embodiments of this application. Detailed Implementation

[0028] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0029] It should be understood that although the terms first, second, etc., may be used herein to describe various components, these components should not be limited to these terms. These terms are used to distinguish one component from another. For example, a first component may be referred to as a second component, and similarly, a second component may be referred to as a first component, without departing from the scope of this application.

[0030] It should be understood that when a component is said to be "on" or "connected" to another component, it can be directly on or connected to the other component, or there may be an inserted component. Other terms used to describe relationships between components should be interpreted in a similar manner.

[0031] It should be noted that the illustrations provided in the embodiments of this application are only schematic representations of the basic concept of this application. Although the illustrations only show the components related to this application and are not drawn according to the actual number, shape and size of the components, the form, quantity and proportion of each component in actual implementation can be arbitrarily changed, and the layout of the components may also be more complex.

[0032] In some embodiments, reference Figure 1 , Figure 1 This is a schematic diagram of a digital-to-analog converter (DAC) circuit. The DAC circuit 10 includes a reference voltage Vref, an adjustable resistor module 11, and an operational amplifier module 12. The adjustable resistor module 11 can adjust the connected resistor branch based on a digital signal to generate an intermediate current Ii. The operational amplifier module 12 generates an intermediate current Ii based on the intermediate current Ii and the reference resistor R. F Generate an analog signal Vo.

[0033] for Figure 1The digital-to-analog converter circuit shown is illustrated using a three-bit binary array as an example. Specifically, when the binary array is "110", the branch current corresponding to resistor R is I2 = Vref / R, the branch current corresponding to resistor 2R is I1 = Vref / 2R, and the branch current corresponding to resistor 4R is I0 = 0. At this time, the intermediate current Ii = I2 + I1 = 3Vref / 2R; the analog signal Vo = -3Vref*R. F / 2R. When the binary array is "101", the branch current corresponding to resistor R is I2 = Vref / R, the branch current corresponding to resistor 2R is I1 = 0, and the branch current corresponding to resistor 4R is I0 = Vref / 4R; at this time, the intermediate current Ii = I2 + I0 = 5Vref / 4R; the analog signal Vo = -5Vref*R F / 4R. When the binary array is "011", the branch current I2 corresponding to resistor R is 0, the branch current I1 corresponding to resistor 2R is Vref / 2R, and the branch current I0 corresponding to resistor 4R is Vref / 4R; at this time, the intermediate current Ii = I1 + I0 = 3Vref / 4R; the analog signal Vo = -3Vref*R F / 4R.

[0034] Based on the above examples, it can be seen that the digital-to-analog converter circuit generates analog signals of different amplitudes by turning on the corresponding resistor branches through the digital signal, thereby completing the conversion from digital signal to analog signal. However, corresponding Figure 1 The analog-to-digital converter (ADC) circuit shown, once its structure is determined (including N resistor branches), can only perform analog-to-digital conversion on a maximum of N-bit digital signals; that is, its maximum resolution is fixed at 2. N .

[0035] To further increase the resolution of the digital-to-analog converter circuit, more resistor branches need to be introduced, which increases the circuit area of ​​the digital-to-analog converter circuit.

[0036] This embodiment provides a digital-to-analog conversion structure, including: a signal conversion module configured to receive a digital signal and output an adjustment signal based on the digital signal; a signal output module including: an impedance adjustment unit connected to the signal conversion module and configured to adjust the impedance value of the impedance adjustment unit based on the adjustment signal; and a signal generation unit connected to the impedance adjustment unit and configured to output an analog signal based on the impedance value of the impedance adjustment unit.

[0037] The digital-to-analog converter structure provided in this embodiment utilizes the device properties of the impedance adjustment unit to make the resistance value of the impedance adjustment unit change with the adjustment signal. The adjustment signal corresponds to the generation of a digital signal, avoiding the correspondence between the digital signal and the circuit settings. This allows the number of bits of the digital signal to be converted to be continuously increased, thereby improving the resolution of the digital-to-analog converter structure.

[0038] The digital-to-analog conversion structure provided in this embodiment will be described in detail below with reference to the accompanying drawings.

[0039] refer to Figure 2 , Figure 2 This is a schematic diagram of the module structure of the digital-to-analog converter structure provided in this embodiment. The digital-to-analog converter structure 100 includes a signal conversion module 101 and a signal output module 102. The signal output module 102 includes an impedance adjustment unit 110 and a signal generation unit 120.

[0040] Signal conversion module 101 is configured to receive digital signals and output an adjustment signal based on the digital signals. Impedance adjustment unit 110 is connected to signal conversion module 101. Impedance adjustment unit 110 is configured to receive the adjustment signal and change its impedance value in response to the adjustment signal. The impedance change of impedance adjustment unit 110 is responsive to changes in the number of adjustment pulses in the adjustment signal or changes in the duty cycle (pulse width) of the adjustment signal. Signal generation unit 120 is connected to impedance adjustment unit 110 and is configured to output an analog signal based on the impedance value of impedance adjustment unit 110.

[0041] The impedance adjustment unit 110 is characterized by its impedance value changing in response to the number of adjustment pulses or the pulse width of the adjustment signal. When the signal conversion module 101 generates different adjustment signals based on different digital signals (different numbers of adjustment pulses or different pulse widths in the adjustment signals), the impedance adjustment unit directly changes the impedance value based on the different adjustment signals, thereby realizing the variable resistor module in the digital-to-analog converter structure 100. Furthermore, the impedance adjustment unit 110 achieves resistance adjustment through its device characteristics, avoiding the circuit correspondence between the number of bits in the digital signal and the impedance adjustment unit 110, thus allowing the number of bits in the digital signal to be converted to continuously increase, improving the resolution of the digital-to-analog converter structure 100.

[0042] In some embodiments, the adjustment signal includes adjustment pulses, and the signal conversion module 101 includes a first pulse generation circuit, which is configured to receive digital signals and generate adjustment signals based on the digital signals. The number of adjustment pulses in the adjustment signal is the number corresponding to the digital signals.

[0043] In some embodiments, different digital signals correspond to different numbers of adjustment pulses; for example, digital signal A corresponds to A number of adjustment pulses in the adjustment signal, digital signal B corresponds to B number of adjustment pulses in the adjustment signal, and so on. In this case, the signal conversion module 101 can generate different adjustment signals based on different digital signals. In one example, the number of adjustment pulses corresponding to a digital signal is the data value of the binary digital signal converted to decimal data minus 1. For example, the number of adjustment pulses corresponding to the digital signal "110" is 6; the number of adjustment pulses corresponding to the digital signal "1100" is 12. In this case, the signal conversion module 101 can generate different adjustment signals based on adjustment signals with different bit widths, avoiding the correspondence between digital signals and circuit settings, thereby allowing the number of bit widths of the digital signal to be converted to continuously increase, improving the resolution of the digital-to-analog converter structure 100.

[0044] refer to Figure 3 , Figure 3 The schematic diagram illustrates the principle of impedance adjustment unit 110 based on the change in the number of adjustment pulses provided in this embodiment. Accordingly, the change in impedance value of impedance adjustment unit 110 responds to the change in the number of adjustment pulses in the adjustment signal. That is, different digital signals correspond to different numbers of adjustment pulses in the adjustment signal, and different numbers of adjustment pulses correspond to changes in the impedance value of impedance adjustment unit 110, so that different digital signals correspond to different changes in the impedance value of impedance adjustment unit 110.

[0045] In some embodiments, the impedance value of the impedance adjustment unit 110 is linearly related to the number of adjustment pulses in the adjustment signal. As described above, the number of adjustment pulses in the adjustment signal is linearly related to the digital signal, making the impedance value of the impedance adjustment unit 110 linearly related to the digital signal. Changes in the same digital signal correspond to changes in the impedance value of the same impedance adjustment unit 110, thereby improving the accuracy of digital-to-analog conversion.

[0046] In some embodiments, the signal conversion module 101 includes a second pulse generation circuit, which is configured to receive a digital signal and generate an adjustment signal based on the digital signal, wherein the duty cycle of the adjustment signal is the same as the duty cycle of the digital signal.

[0047] In some embodiments, different digital signals correspond to different duty cycles of the adjustment signal; for example, digital signal C corresponds to an adjustment signal with a duty cycle of C, digital signal D corresponds to an adjustment signal with a duty cycle of ... D. In this case, the signal conversion module 101 can generate different adjustment signals based on different digital signals. In one example, the duty cycle of the adjustment signal corresponding to a digital signal is the ratio of the current number of bits in the digital signal to its maximum number. For example, the duty cycle of the adjustment signal corresponding to the digital signal "110" is 110B / 2. 3The digital signal "1100" corresponds to an adjustment signal with a duty cycle of 1100B / 2. 4 At this time, the signal conversion module 101 can generate different adjustment signals based on adjustment signals of different bit lengths, avoiding the correspondence between digital signals and circuit settings, thereby enabling the number of bits of the digital signal to be converted to continuously increase and improving the resolution of the digital-to-analog converter structure 100.

[0048] refer to Figure 4 , Figure 4 This embodiment illustrates the principle that the impedance value of the impedance adjustment unit is based on the change in the pulse width of the adjustment signal. Accordingly, the change in the impedance value of the impedance adjustment unit 110 responds to the change in the duty cycle of the adjustment signal. That is, different digital signals correspond to different duty cycles of the adjustment signal, and different duty cycles correspond to changes in the impedance value of the impedance adjustment unit 110, so that different digital signals correspond to different changes in the impedance value of the impedance adjustment unit 110.

[0049] In some embodiments, the impedance value of the impedance adjustment unit 110 is linearly related to the duty cycle of the adjustment signal. As described above, the change in the duty cycle of the adjustment signal is linearly related to the digital signal, making the impedance value of the impedance adjustment unit 110 linearly related to the digital signal. The same change in the digital signal corresponds to the same change in the impedance value of the impedance adjustment unit 110, thereby improving the accuracy of digital-to-analog conversion.

[0050] In some embodiments, the impedance adjustment unit 110 includes a memristor-based implementation.

[0051] In some embodiments, the impedance adjustment unit 110 includes a phase change memory (PCM). In one example, under the control of an adjustment pulse with a certain pulse width and a certain pulse amplitude, the impedance value of the phase change memory increases linearly with the number of adjustment pulses.

[0052] In some embodiments, the phase change memory cell includes a chalcogenide compound, which includes at least one of compounds of arsenic (As), selenium (Se) and germanium (Ge), compounds of AsSeGe and silicon (Si), compounds of AsSeGeSi and indium (In), and compounds of AsSeGe and indium (In).

[0053] In some embodiments, the impedance adjustment unit 110 includes a resistive random-access memory (RRAM).

[0054] It should be noted that in the following description of this embodiment, the impedance value of the impedance adjustment unit 110 is described based on the change in the number of adjustment pulses. Those skilled in the art can apply the corresponding technical features to the embodiment where the impedance value of the impedance adjustment unit 110 is based on the change in the duty cycle of the adjustment signal to obtain a new embodiment.

[0055] Continue to refer to Figure 2 In some embodiments, the first end of the impedance adjustment unit 110 is connected to the output end of the signal conversion module 101 and the output end of the signal generation unit 120, and the second end of the impedance adjustment unit 110 is connected to the input end of the signal generation unit.

[0056] refer to Figure 2 and Figure 5 , Figure 5 This is a schematic diagram of the digital-to-analog converter structure provided in this embodiment. The signal generation unit 120 is configured to receive a reference current and output an analog signal based on the reference current and the impedance value of the impedance adjustment unit 110. The signal generation unit 120 includes an operational amplifier 201, the non-inverting input terminal of which is used to receive the reference current, the negative input terminal is grounded, and the output terminal is used to output the analog signal Vout.

[0057] based on Figure 5 The operational amplifier 201 with the connection shown has an analog signal Vout = Iref * R, where R is the impedance value of the impedance adjustment unit 110.

[0058] In some embodiments, the reference current is realized through a reference voltage Vref and a reference resistor Rref. Specifically, the non-inverting input of operational amplifier 201 is connected to the first terminal of the reference resistor Rref, and the second terminal of the reference resistor Rref is used to receive the reference voltage Vref. In this case, the reference current Iref received at the non-inverting input of operational amplifier 201 is Iref = Vref / Rref. Then, Vout = Vref * R / Rref.

[0059] for Figure 5 The digital-to-analog converter structure 100 shown includes a signal conversion module 101 that performs real-time conversion on the received digital signal to generate a corresponding adjustment signal, an impedance adjustment unit 110 that adjusts the impedance value in real-time based on the adjustment signal, and a signal generation unit 120 that generates a changing analog signal based on the changing impedance value of the impedance adjustment unit 110. Once the impedance value of the impedance adjustment unit 110 stabilizes, the analog signal level output by the signal generation unit 120 also stabilizes. Therefore, for... Figure 5 The digital-to-analog converter structure 100 shown requires the impedance value of the impedance adjustment unit 110 to be stabilized before the analog signal is output, thus completing the conversion from digital signal to analog signal.

[0060] In some embodiments, the signal output module 102 further includes a control unit configured to receive a switching signal, control the impedance adjustment unit to acquire an adjustment signal based on the switching signal, or the adjustment signal generation unit to output an analog signal.

[0061] In one example, the control unit includes an output switch 401, which is located at the output of the signal generation unit 120. The output switch 401 is in a closed state and an open state based on the control of a switching signal. When the output switch 401 is in the open state, the output path of the digital-to-analog converter 100 is disconnected, and the signal generation unit 120 generates a changing analog signal based on the changing impedance value of the impedance adjustment unit 110. After the impedance value of the impedance adjustment unit 110 has changed, the output switch 401 switches to the closed state, and the digital-to-analog converter 100 completes the output.

[0062] In some embodiments, after receiving a digital signal, the digital-to-analog converter 100 provides a switching signal based on a preset time to close the output switch 401. The preset time is used to ensure that the impedance adjustment unit 110 completes the impedance value change based on the adjustment signal, thereby improving the accuracy of the digital-to-analog converter 100.

[0063] refer to Figure 6 , Figure 6 This is a schematic diagram of the digital-to-analog converter structure including a control unit provided in this embodiment. In some embodiments, the control unit includes a control switch 301. The first selection terminal of the control switch 301 is connected to the output terminal of the signal conversion module 101, the second selection terminal is connected to the signal generation unit 120, and the control terminal is connected to the impedance adjustment unit 110. The control switch 301 is configured to control the control terminal to be electrically connected to the first selection terminal or the second selection terminal based on the switching signal.

[0064] Specifically, the control terminal of the control switch 301 is connected to the non-inverting input terminal of the operational amplifier 201 through the impedance adjustment unit 110, the first selection terminal is connected to the output terminal of the signal conversion module 101, and the second selection terminal is connected to the output terminal of the signal generation unit 120.

[0065] It should be noted that, in Figure 6 In the example, the control switch 301 is based on a three-terminal switch, which can be a single-pole double-throw switch. In specific applications, the three-terminal switch can also be based on two two-terminal switches, which can be MOS switches.

[0066] Specifically, when the control switch 301 controls the control terminal to be electrically connected to the first selection terminal based on the switching signal, the impedance adjustment unit 110 changes the impedance value in response to the adjustment signal; when the control switch 301 controls the control terminal to be electrically connected to the second selection terminal based on the switching signal, the signal generation unit 120 outputs an analog signal based on the impedance value of the impedance adjustment unit 110.

[0067] refer to Figure 6 and Figure 7 , Figure 7 This is provided in this embodiment. Figure 6 The timing diagram of each signal in the digital-to-analog converter structure is shown.

[0068] When the control terminal of the control switch 301 is electrically connected to the first selection terminal, the signal conversion module 101 is connected to the impedance adjustment unit 110 through the control switch 301. The signal conversion module 101 performs real-time conversion on the received digital signal to generate a corresponding adjustment signal, and the impedance adjustment unit 110 adjusts the impedance value in real time based on the adjustment signal.

[0069] Once the impedance value of the impedance adjustment unit 110 stabilizes, it provides a switching signal to switch the connection relationship of the control switch 301.

[0070] When the control terminal of the control switch 301 is electrically connected to the second selection terminal, the operational amplifier 201 forms positive feedback, and the signal generation unit 120 generates an analog signal based on the impedance value of the impedance adjustment unit 110.

[0071] for Figure 6 The example digital-to-analog converter structure 100 uses a control switch 301 to switch its state, enabling the structure to include a writing stage (impedance adjustment unit 110 adjusts the impedance value based on the digital signal) and a reading stage (signal generation unit 120 outputs an analog signal based on the impedance adjustment unit 110). The conversion from digital to analog signals can be achieved simply by controlling the control switch 301, resulting in a simple structure and low cost.

[0072] The digital-to-analog converter structure provided in this embodiment utilizes the device properties of the impedance adjustment unit to make the resistance value of the impedance adjustment unit change with the adjustment signal. The adjustment signal corresponds to the generation of a digital signal, avoiding the correspondence between the digital signal and the circuit settings. This allows the number of bits of the digital signal to be converted to be continuously increased, thereby improving the resolution of the digital-to-analog converter structure.

[0073] It should be noted that, without conflict, the features applied for in the digital-to-analog conversion structure provided in the above embodiments can be randomly combined to obtain new digital-to-analog conversion structure embodiments.

[0074] This application also provides a control method applied to the digital-to-analog conversion structure provided in the above embodiments, which aims to improve the resolution of digital-to-analog conversion.

[0075] In some embodiments, the control method includes: acquiring a digital signal and outputting an adjustment signal based on the digital signal; performing a write operation in response to the adjustment signal to adjust the impedance value of an impedance adjustment unit; and performing a read operation to output an analog signal based on the impedance value of the impedance adjustment unit.

[0076] The control method provided in this embodiment will be described in detail below with reference to the accompanying drawings. Figure 1 and Figure 8 , Figure 8 This is a flowchart illustrating each step in the control method provided in this embodiment.

[0077] Step 501: Acquire the digital signal and output the adjustment signal based on the digital signal.

[0078] In some embodiments, the adjustment signal includes adjustment pulses, and the signal conversion module includes a first pulse generation circuit, which is configured to receive a digital signal and generate an adjustment signal based on the digital signal, wherein the number of adjustment pulses in the adjustment signal is the number corresponding to the digital signal.

[0079] In some embodiments, different digital signals correspond to different numbers of adjustment pulses; for example, digital signal A corresponds to A number of adjustment pulses in the adjustment signal, digital signal B corresponds to B number of adjustment pulses in the adjustment signal, and so on. In this case, the signal conversion module 101 can generate different adjustment signals based on different digital signals. In one example, the number of adjustment pulses corresponding to a digital signal is the data value of the binary digital signal converted to decimal data minus 1. For example, the number of adjustment pulses corresponding to the digital signal "110" is 6; the number of adjustment pulses corresponding to the digital signal "1100" is 12. In this way, the signal conversion module can generate different adjustment signals based on adjustment signals with different bit widths, avoiding the correspondence between digital signals and circuit settings, thereby allowing the number of bit widths of the digital signal to be converted to continuously increase and improving the resolution of the digital-to-analog conversion structure.

[0080] Step 502: Adjust the impedance value of the impedance adjustment unit.

[0081] Specifically, in response to the adjustment signal, a write operation is performed to adjust the impedance value of the impedance adjustment unit.

[0082] In some embodiments, the write operation includes: the signal conversion module 101 outputs an adjustment signal based on a digital signal, the adjustment signal including adjustment pulses, the number of adjustment pulses in the adjustment signal being the number corresponding to the digital signal; the impedance adjustment unit 110 responds to the adjustment pulses in the adjustment signal and gradually changes the impedance value based on each adjustment pulse.

[0083] refer to Figure 3 The impedance value of the impedance adjustment unit changes in response to the change in the number of adjustment pulses in the adjustment signal. That is, different digital signals correspond to different numbers of adjustment pulses in the adjustment signal, and different numbers of adjustment pulses correspond to changes in the impedance value of the impedance adjustment unit, so that different digital signals correspond to different changes in the impedance value of the impedance adjustment unit.

[0084] In some embodiments, the impedance value of the impedance adjustment unit is linearly related to the number of adjustment pulses in the adjustment signal. As described above, the number of adjustment pulses in the adjustment signal is linearly related to the digital signal, making the impedance value of the impedance adjustment unit linearly related to the digital signal. Changes in the same digital signal correspond to changes in the impedance value of the same impedance adjustment unit, thereby improving the accuracy of the digital-to-analog conversion. Step 503: Output an analog signal based on the impedance value of the impedance adjustment unit.

[0085] Specifically, a reading operation is performed, and an analog signal is output based on the impedance value of the impedance adjustment unit.

[0086] In some embodiments, the reading operation includes: providing a reference current, and the signal generation unit 120 outputting an analog signal based on the reference current and the impedance value of the impedance adjustment unit 110.

[0087] refer to Figure 5 The signal conversion module 101 performs real-time conversion on the received digital signal to generate a corresponding adjustment signal. The impedance adjustment unit 110 adjusts the impedance value in real-time based on the adjustment signal. The signal generation unit 120 generates a changing analog signal based on the changing impedance value of the impedance adjustment unit 110. When the impedance value of the impedance adjustment unit 110 stabilizes, the analog signal level output by the signal generation unit 120 stabilizes. Therefore, for Figure 5 The digital-to-analog converter structure 100 shown requires the impedance value of the impedance adjustment unit 110 to be stabilized before the analog signal is output, thus completing the conversion from digital signal to analog signal.

[0088] The control method provided in this embodiment is applied to the digital-to-analog converter structure provided in the above embodiment. By utilizing the device properties of the impedance adjustment unit, the resistance value of the impedance adjustment unit changes with the adjustment signal. The adjustment signal corresponds to the generation of a digital signal, avoiding the correspondence between the digital signal and the circuit settings. This allows the number of bits of the digital signal to be converted to increase continuously, thereby improving the resolution of the digital-to-analog converter structure.

[0089] In some embodiments, the control method further includes: receiving a switching signal; and switching between the write operation and the read operation based on the switching signal.

[0090] refer to Figure 9 , Figure 9 This is a flowchart illustrating each step in the control method, including switching signal control, provided in this embodiment.

[0091] Before performing step 501, step 510 is also included, which involves receiving a switching signal and performing a write operation based on the switching signal.

[0092] refer to Figure 6 and Figure 7 When the control terminal of the switching signal control switch 301 is electrically connected to the first selection terminal, the signal conversion module 101 is connected to the impedance adjustment unit 110 through the control switch 301. The signal conversion module 101 performs real-time conversion on the received digital signal to generate the corresponding adjustment signal, and the impedance adjustment unit 110 adjusts the impedance value in real time based on the adjustment signal.

[0093] Specifically, the digital signal input signal conversion module 101 generates a corresponding number of adjustment pulses. Simultaneously, the control terminal of the switching signal control switch 301 is electrically connected to the first selection terminal. At this time, the voltage pulses generated by the signal conversion module 101 are applied to the impedance adjustment unit 110 (phase-change storage unit, resistive-change storage unit). Since the other end of the impedance adjustment unit 110 is connected to the positive terminal of the operational amplifier, and the negative terminal of the operational amplifier is connected to ground, according to the operational amplifier principle, the voltage across the impedance adjustment unit 110 is the pulse voltage, and its resistance will be affected by the pulses, gradually increasing.

[0094] After step 502 is executed and before step 503 is executed, step 520 is also included, in which a switching signal is received and a reading operation is performed based on the switching signal.

[0095] refer to Figure 6 and Figure 7 When the control terminal of the switching signal control switch 301 is electrically connected to the second selection terminal, the operational amplifier 201 forms positive feedback, and the signal generation unit 120 generates an analog signal based on the impedance value of the impedance adjustment unit 110.

[0096] Specifically, once the adjustment pulse input ends, the impedance value of the impedance adjustment unit 110 is adjusted, and the control terminal of the switching signal control switch 301 is electrically connected to the second selection terminal. At this time, the upper end of the impedance adjustment unit 110 is connected to the output terminal of the operational amplifier. Simultaneously, the positive terminal of the operational amplifier receives a reference current (this reference current can be the directly input current, or a reference current generated based on a reference voltage or a reference resistor). Since the voltage at the positive terminal of the operational amplifier is equal to 0, the current flowing through the impedance adjustment unit 110 is the reference current, and the voltage at the output terminal of the operational amplifier is equal to the impedance value of the impedance adjustment unit 110 multiplied by the reference current.

[0097] By introducing a switching signal, the digital-to-analog converter 100 can complete the conversion of digital signals to analog signals simply by controlling the control switch 301. The structure is simple and the cost is low.

[0098] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the detailed descriptions of other embodiments above, which will not be repeated here.

[0099] The basic concepts have been described above. Obviously, for those skilled in the art, the detailed disclosure above is merely illustrative and does not constitute a limitation of this application. Although not explicitly stated herein, those skilled in the art may make various modifications, improvements, and corrections to this application. Such modifications, improvements, and corrections are suggested in this application, and therefore remain within the spirit and scope of the exemplary embodiments of this application.

[0100] The above provides a detailed description of the digital-to-analog conversion structure and control method provided in the embodiments of this application. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A digital-to-analog conversion structure, characterized by, The signal conversion module is configured to receive a digital signal and output an adjustment signal based on the digital signal, the adjustment signal comprising adjustment pulses. The signal output module comprises: The impedance adjustment unit is connected to the signal conversion module and is configured to adjust an impedance value of the impedance adjustment unit based on a change in the number of adjustment pulses or a change in the duty cycle of the adjustment signal; The signal generation unit is connected to the impedance adjustment unit and is configured to output an analog signal based on the impedance value of the impedance adjustment unit.

2. The digital-to-analog conversion structure according to claim 1, wherein If the change in the impedance value is in response to the change in the number of adjustment pulses, the signal conversion module comprises a first pulse generation circuit configured to receive the digital signal and generate the adjustment signal based on the digital signal, the number of adjustment pulses in the adjustment signal corresponding to the number of the digital signal; If the change in the impedance value is in response to the change in the duty cycle of the adjustment signal, the signal conversion module comprises a second pulse generation circuit configured to receive the digital signal and generate the adjustment signal based on the digital signal, the duty cycle of the adjustment signal corresponding to the duty cycle of the digital signal. The impedance value is linearly related to the number of adjustment pulses.

3. The digital-to-analog conversion structure of claim 2, wherein, A first end of the impedance adjustment unit is connected to an output end of the signal conversion module and an output end of the signal generation unit; a second end of the impedance adjustment unit is connected to an input end of the signal generation unit.

4. The digital-to-analog conversion structure of claim 1, wherein, The impedance adjustment unit comprises a phase change memory unit or a resistance change memory unit.

5. The digital-to-analog conversion structure of claim 4, wherein, The signal generation unit is configured to receive a reference current and output the analog signal based on the reference current and the impedance value of the impedance adjustment unit; the signal generation unit comprises an operational amplifier, a non-inverting input end for receiving the reference current and connected to the first end of the impedance adjustment unit, a negative input end grounded, and an output end for outputting the analog signal.

6. The digital-to-analog conversion structure of claim 1, wherein, The signal output module further comprises a control unit configured to receive a switching signal and control the impedance adjustment unit to obtain the adjustment signal or control the signal generation unit to output the analog signal based on the switching signal.

7. The digital-to-analog conversion structure of claim 1, wherein, The control unit comprises a control switch, a first selection end connected to an output end of the signal conversion module, a second selection end connected to an output end of the signal generation unit, and a control end connected to the impedance adjustment unit.

8. The digital-to-analog conversion structure of claim 7, wherein, The control switch is configured to control the control end to be electrically connected to the first selection end or the second selection end based on the switching signal. When the control switch controls the control end to be electrically connected to the first selection end based on the switching signal, the impedance adjustment unit changes the impedance value in response to the adjustment signal. When the control switch controls the control end to be electrically connected to the second selection end based on the switching signal, the signal generation unit outputs the analog signal based on the impedance value of the impedance adjustment unit. The signal conversion module is configured to receive a digital signal and output an adjustment signal based on the digital signal, the adjustment signal comprising adjustment pulses.

9. A method of controlling a digital-to-analog conversion structure as claimed in any one of the claims 1-8, characterized in that ​ ​ performing a write operation in response to the adjusting signal, adjusting an impedance value of the impedance adjusting unit based on a change in the number of the adjusting pulses or a change in the duty cycle of the adjusting signal; performing a read operation, outputting an analog signal based on the impedance value of the impedance adjusting unit.

10. The control method according to claim 9, characterized by The write operation comprises: The signal conversion module outputs the adjusting signal based on the digital signal, the adjusting signal comprising adjusting pulses, the number of the adjusting pulses in the adjusting signal being the number corresponding to the digital signal; The impedance adjusting unit responds to the adjusting pulses in the adjusting signal and changes the impedance value step by step based on each adjusting pulse; The read operation comprises: providing a reference current; and the signal generation unit outputs an analog signal based on the reference current and the impedance value of the impedance adjusting unit.

11. The control method according to claim 9 or 10, characterized by, Further comprising: receiving a switching signal; switching between the write operation and the read operation based on the switching signal.

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