Digital-to-analog conversion structure and control method

Abstract

The invention relates to the field of electronic circuit devices, and provides a digital-to-analog conversion structure and a control method, and the digital-to-analog conversion structure comprises a signal conversion module which is configured to receive a digital signal and output an adjustment signal based on the digital signal; the signal output module comprises an impedance adjusting unit which is connected with the signal conversion module and is configured to adjust the impedance value of the impedance adjusting unit based on the adjusting signal; the signal generating unit is connected with the impedance adjusting unit and is configured to output an analog signal based on the impedance value of the impedance adjusting unit, the resistance value of the impedance adjusting unit is changed along with the change of an adjusting signal through the device property of the impedance adjusting unit, and the adjusting signal corresponds to the generation of a digital signal; the corresponding relation between the digital signal and the circuit setting is avoided, so that the digit of the digital signal to be converted can be continuously increased, and the resolution of the digital-to-analog conversion structure is improved.

Description

Technical Field

[0001] The present application relates to the field of electronic circuit devices, and in particular to a digital-to-analog conversion structure and a control method. Background Art

[0002] Digital-to-analog conversion is the process of converting discrete digital quantities into continuously changing analog quantities. The circuit or device that implements this function is called a digital-to-analog conversion circuit, usually called a digital-to-analog converter or DAC (Digital Analog Converter).

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

[0004] However, the digital-to-analog converter has the problems of complex circuits, large area, and difficulty in changing its sampling resolution after the structure is fixed. Summary of the invention

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

[0006] In a first aspect, the present 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, configured to adjust the impedance value of the impedance adjustment unit based on the adjustment signal; a signal generating unit, connected to the impedance adjustment unit, configured to output an analog signal based on the impedance value of the impedance adjustment unit.

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

[0009] In some embodiments, 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; and a second end of the impedance adjustment unit is connected to an 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 generating 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 adjusting unit; the signal generating unit includes: an operational amplifier, a positive phase input terminal for receiving the reference current and connected to the first end of the impedance adjusting unit, a negative phase 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, and control the impedance adjustment unit to obtain 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 end connected to the output end of the signal conversion module, a second selection end connected to the output end of the signal generating unit, and a control end connected to the impedance adjustment unit; the control switch is configured to: based on the switching signal, control the control end to be electrically connected to the first selection end or the second selection end; 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 generating unit outputs an analog signal based on the impedance value of the impedance adjustment unit.

[0014] In a second aspect, the present application provides a control method, which is applied to the digital-to-analog conversion structure mentioned in the first aspect above, including: 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; 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: the signal conversion module outputs the adjustment signal based on the digital signal, the adjustment signal includes adjustment pulses, and the number of the adjustment pulses in the adjustment signal is the number corresponding to the digital signal; the impedance adjustment unit responds to the adjustment pulses in the adjustment signal and gradually changes the impedance value based on each adjustment pulse; the read operation includes: providing a reference current; the signal generation unit outputs 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 writing operation and the reading operation based on the switching signal.

[0017] The digital-to-analog conversion structure provided in the present application uses the device properties of the impedance adjustment unit so that the resistance value of the impedance adjustment unit changes with the change of the adjustment signal, and the adjustment signal is generated corresponding to the digital signal, thereby avoiding the correspondence between the digital signal and the circuit setting, thereby enabling the number of bits of the digital signal to be converted to be continuously increased, thereby improving the resolution of the digital-to-analog conversion structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The technical solution and other beneficial effects of the present application will be made apparent by describing in detail the specific implementation methods of the present application in conjunction with the accompanying drawings.

[0019] Figure 1 It is a structural schematic diagram of a digital-to-analog conversion circuit;

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

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

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

[0023] Figure 5 is a specific structural diagram of a digital-to-analog conversion structure provided in some embodiments of the present application;

[0024] Figure 6 is a structural schematic diagram of a digital-to-analog conversion structure including a control unit provided in some embodiments of the present application;

[0025] Figure 7 Some embodiments of the present application provide Figure 6 A schematic diagram of the timing sequence corresponding to each signal in the digital-to-analog conversion structure shown;

[0026] Figure 8 It is a flowchart corresponding to each step in the control method provided in some embodiments of the present application;

[0027] Fig. 9 It is a flowchart corresponding to each step in the control method including switching signal control provided in some embodiments of the present application. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present 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 component. 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 the present application.

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

[0031] It should be noted that the illustrations provided in the embodiments of the present application are only used to illustrate the basic concept of the present application in a schematic manner. Although the illustrations only show components related to the present application and are not drawn according to the number, shape and size of components in actual implementation, the type, quantity and proportion of each component in actual implementation may be changed arbitrarily, and the component layout may also be more complicated.

[0032] In some embodiments, reference Figure 1 , Figure 1 The schematic diagram of the structure of a digital-to-analog conversion circuit is shown in FIG. 1 . The digital-to-analog conversion circuit 10 includes: a reference voltage Vref, an adjustable resistance module 11, and an operational amplifier module 12. The adjustable resistance module 11 can adjust the connected resistance branch based on the 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 resistance R F Generate an analog signal Vo.

[0033] for Figure 1The digital-to-analog conversion circuit shown in the figure is explained by taking the digital signal as a three-digit binary array as an example, as follows: when the binary array is "110", the branch current I2 corresponding to the resistor R is Vref / R, the branch current I1 corresponding to the resistor 2R is Vref / 2R, and the branch current I0 corresponding to the resistor 4R is 0; at this time, the intermediate current Ii is I2+I1=3Vref / 2R; the analog signal Vo is -3Vref*R F / 2R. When the binary array is "101", the branch current I2 corresponding to the resistor R is Vref / R, the branch current I1 corresponding to the resistor 2R is 0, and the branch current I0 corresponding to the resistor 4R is Vref / 4R; at this time, the intermediate current Ii is I2+I0=5Vref / 4R; the analog signal Vo is -5Vref*R F / 4R. When the binary array is "011", the branch current I2 corresponding to the resistor R is 0, the branch current I1 corresponding to the resistor 2R is Vref / 2R, and the branch current I0 corresponding to the resistor 4R is Vref / 4R; at this time, the intermediate current Ii is I1+I0 is 3Vref / 4R; the analog signal Vo is -3Vref*R F / 4R.

[0034] Based on the above examples, it can be seen that the digital-to-analog conversion circuit generates analog signals with different amplitudes by turning on the corresponding resistance branches through digital signals, thereby completing the conversion of digital signals to analog signals. Figure 1 The digital-to-analog conversion circuit shown in FIG. 1 shows a digital-to-analog conversion circuit. When the structure of the digital-to-analog conversion circuit is determined (the determined digital-to-analog conversion circuit includes N resistor branches), the digital-to-analog conversion circuit can only realize digital-to-analog conversion of N-bit digital signals at most, that is, the maximum resolution of the digital-to-analog conversion circuit is fixed to 2. N .

[0035] On this basis, if one wants to further increase the resolution of the digital-to-analog conversion circuit, it is necessary to introduce more resistance branches, which increases the circuit area of ​​the digital-to-analog conversion circuit.

[0036] The present 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, configured to: adjust the impedance value of the impedance adjustment unit based on the adjustment signal; a signal generating unit, connected to the impedance adjustment unit, configured to: output an analog signal based on the impedance value of the impedance adjustment unit.

[0037] The digital-to-analog conversion structure provided in this embodiment uses the device properties of the impedance adjustment unit so that the resistance value of the impedance adjustment unit changes with the change of the adjustment signal, and the adjustment signal is generated corresponding to the digital signal, thereby avoiding the correspondence between the digital signal and the circuit setting, so that the number of bits of the digital signal to be converted can be continuously increased, thereby improving the resolution of the digital-to-analog conversion structure.

[0038] The digital-to-analog conversion structure provided in this embodiment is 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 conversion structure provided in this embodiment. The digital-to-analog conversion 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] The signal conversion module 101 is configured to receive a digital signal and output an adjustment signal based on the digital signal. The impedance adjustment unit 110 is connected to the signal conversion module 101, and the impedance adjustment unit 110 is configured to receive the adjustment signal and change its own impedance value in response to the adjustment signal, wherein the impedance value change of the impedance adjustment unit 110 responds to the change in the number of adjustment pulses in the adjustment signal or the change in the duty cycle (pulse width change) of the adjustment signal. The signal generation unit 120 is connected to the impedance adjustment unit 110, and the signal generation unit 120 is configured to output an analog signal based on the impedance value of the impedance adjustment unit 110.

[0041] Among them, the device characteristics of the impedance adjustment unit 110 include that the impedance value changes in response to the number of adjustment pulses in the adjustment signal or the pulse width of the adjustment signal. When the signal conversion module 101 generates different adjustment signals based on different digital signals (the number of adjustment pulses in the adjustment signal is different, or the pulse width of the adjustment signal is different), the impedance adjustment unit directly completes the change of the impedance value based on the different adjustment signals, thereby realizing the variable resistance module in the digital-to-analog conversion structure 100. In addition, the impedance adjustment unit 110 realizes resistance adjustment through device characteristics, avoiding the circuit correspondence between the number of bits of the digital signal and the impedance adjustment unit 110, so that the number of bits of the digital signal to be converted can be continuously increased, and the resolution of the digital-to-analog conversion structure 100 is improved.

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

[0043] In some embodiments, different digital signals correspond to different numbers of adjustment pulses; for example, the number of adjustment pulses in the adjustment signal corresponding to digital signal A is A, and the number of adjustment pulses in the adjustment signal corresponding to digital signal B is B... At this time, 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 the digital signal is the data value -1 converted from the binary digital signal to decimal data. 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. At this time, the signal conversion module 101 can generate different adjustment signals based on adjustment signals of different bits, avoiding the correspondence between the digital signal and the circuit setting, so that the number of bits of the digital signal to be converted can be continuously increased, thereby improving the resolution of the digital-to-analog conversion structure 100.

[0044] refer to Figure 3 , Figure 3 The impedance value of the impedance adjustment unit provided in this embodiment is based on the change principle of the number of adjustment pulses. Accordingly, the change of the impedance value of the impedance adjustment unit 110 responds to the change of 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 110, so that different digital signals correspond to different impedance values ​​of the impedance adjustment unit 110.

[0045] In some embodiments, the impedance value of the impedance adjustment unit 110 is linearly correlated with the number of adjustment pulses in the adjustment signal. Based on the foregoing description, it can be seen that the number of adjustment pulses in the adjustment signal is linearly correlated with the digital signal, so that the impedance value of the impedance adjustment unit 110 is linearly correlated with the digital signal, and the change of the same digital signal corresponds to the change of 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 generating 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 duty cycle corresponding to the digital signal.

[0047] In some embodiments, different digital signals correspond to different duty cycles of the adjustment signal; for example, the duty cycle of the adjustment signal corresponding to the digital signal C is C, and the duty cycle of the adjustment signal corresponding to the digital signal D is ... D. At this time, 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 the digital signal is: the ratio of the current value of the digital signal bit to the maximum value. For example, the duty cycle of the adjustment signal corresponding to the digital signal "110" is 110B / 2 3, the duty cycle of the digital signal "1100" corresponding to the adjustment signal is 1100B / 2 4 At this time, the signal conversion module 101 can generate different adjustment signals based on adjustment signals of different bit numbers, avoiding the correspondence between digital signals and circuit settings, so that the bit number of the digital signal to be converted can be continuously increased, and the resolution of the digital-to-analog conversion structure 100 is improved.

[0048] refer to Figure 4 , Figure 4 The impedance value of the impedance adjustment unit provided in this embodiment is based on the pulse width of the adjustment signal. Accordingly, the impedance value of the impedance adjustment unit 110 changes in response to 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 impedance values ​​of the impedance adjustment unit 110.

[0049] In some embodiments, the impedance value of the impedance adjustment unit 110 is linearly correlated with the duty cycle of the adjustment signal. Based on the foregoing description, it can be seen that the change in the duty cycle in the adjustment signal is linearly correlated with the digital signal, so that the impedance value of the impedance adjustment unit 110 is linearly correlated with the digital signal, and the change of the same digital signal corresponds to the change of the impedance value of the same impedance adjustment unit 110, thereby improving the accuracy of digital-to-analog conversion.

[0050] In some embodiments, the impedance adjustment unit 110 is implemented based on a memristor.

[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 unit increases linearly with the number of adjustment pulses.

[0052] In some embodiments, the phase change memory cell includes a chalcogenide compound, the chalcogenide compound including at least one of a compound of arsenic (As), selenium (Se) and germanium (Ge), a compound of AsSeGe and silicon (Si), a compound of AsSeGeSi and indium (In), and a compound 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 subsequent description of this embodiment, the change in the impedance value of the impedance adjustment unit 110 based on the number of adjustment pulses is taken as an example. Those skilled in the art can apply the corresponding technical features to the embodiment in which the impedance value of the impedance adjustment unit 110 changes based on the duty cycle of the adjustment signal to obtain a new embodiment.

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

[0056] refer to Figure 2 and Figure 5 , Figure 5 A schematic diagram of a specific structure of the digital-to-analog conversion structure provided in this embodiment. The signal generating 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 adjusting unit 110. The signal generating unit 120 includes an operational amplifier 201, wherein the positive phase input terminal of the operational amplifier 201 is used to receive the reference current, the negative phase input terminal is grounded, and the output terminal is used to output the analog signal Vout.

[0057] based on Figure 5 For the operational amplifier 201 with the connection relationship shown, the 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 by a reference voltage Vref and a reference resistor Rref, that is, the non-inverting input terminal of the operational amplifier 201 is connected to the first end of the reference resistor Rref, and the second end of the reference resistor Rref is used to receive the reference voltage Vref. At this time, the reference current Iref received by the non-inverting input terminal of the operational amplifier 201 is equal to Vref / Rref. At this time, Vout=Vref*R / Rref.

[0059] for Figure 5 In the digital-to-analog conversion structure 100 shown, 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, and the signal generation unit 120 generates a changing analog signal based on the changed impedance value of the impedance adjustment unit 110. When the impedance value of the impedance adjustment unit 110 is stable, the analog signal level output by the signal generation unit 120 is stable. Figure 5 In the digital-to-analog conversion structure 100 shown, when a digital signal is input into the digital-to-analog conversion structure 100 , the impedance value of the impedance adjustment unit 110 needs to be stabilized before the analog signal is output, thereby completing the conversion from the digital signal to the analog signal.

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

[0061] In one example, the control unit includes an output switch 401, which is disposed at the output end of the signal generating unit 120, and the output switch 401 is in a closed state and an open state based on the control of the switching signal. When the output switch 401 is in an open state, the output path of the digital-to-analog conversion structure 100 is disconnected, and the signal generating unit 120 generates a changing analog signal based on the changed impedance value of the impedance adjusting unit 110; when the impedance value of the impedance adjusting unit 110 is changed, the output switch 401 is switched to a closed state, and the digital-to-analog conversion structure 100 completes the output.

[0062] In some embodiments, after receiving the digital signal, the digital-to-analog conversion structure 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 change of the impedance value based on the adjustment signal, thereby improving the accuracy of the digital-to-analog conversion structure 100.

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

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

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

[0066] Among them, when the control switch 301 controls the control end to be electrically connected to the first selection end 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 end to be electrically connected to the second selection end 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 embodiment provides Figure 6 A timing diagram corresponding to each signal in the digital-to-analog conversion structure shown.

[0068] When the control end of the control switch 301 is electrically connected to the first selection end, 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] When the impedance value of the impedance adjustment unit 110 is stabilized, a switching signal is provided to switch the connection relationship of the control switch 301 .

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

[0071] for Figure 6 The example digital-to-analog conversion structure 100 realizes the state switching of the digital-to-analog conversion structure 100 by controlling the switch 301, so that the digital-to-analog conversion structure 100 includes a writing phase (the impedance adjustment unit 110 adjusts the impedance value based on the digital signal) and a reading phase (the signal generation unit 120 completes the analog signal output based on the impedance adjustment unit 110). The digital-to-analog conversion structure 100 can complete the conversion of digital signals to analog signals only by controlling the control switch 301, and has a simple structure and low cost.

[0072] The digital-to-analog conversion structure provided in this embodiment uses the device properties of the impedance adjustment unit so that the resistance value of the impedance adjustment unit changes with the change of the adjustment signal, and the adjustment signal is generated corresponding to the digital signal, thereby avoiding the correspondence between the digital signal and the circuit setting, so that the number of bits of the digital signal to be converted can be continuously increased, thereby improving the resolution of the digital-to-analog conversion structure.

[0073] It should be noted that, in the absence of conflict, the features applied for in the digital-to-analog conversion structure provided in the above embodiments can be randomly combined to obtain a new digital-to-analog conversion structure embodiment.

[0074] An embodiment of the present application also provides a control method, which is applied to the digital-to-analog conversion structure provided in the above embodiment, aiming to improve the resolution of the 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 the impedance adjustment unit; performing a read operation to output an analog signal based on the impedance value of the impedance adjustment unit.

[0076] The control method provided by this embodiment is described in detail below with reference to the accompanying drawings. Figure 1 and Figure 8 , Figure 8 This is a schematic diagram of the flow chart corresponding to each step in the control method provided in this embodiment.

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

[0078] In some embodiments, the adjustment signal includes an adjustment pulse, the signal conversion module includes a first pulse generating circuit, the first pulse generating circuit is configured to receive a digital signal and generate an adjustment signal based on the digital signal, and 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, the number of adjustment pulses in the adjustment signal corresponding to digital signal A is A, and the number of adjustment pulses in the adjustment signal corresponding to digital signal B is B... At this time, 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 the digital signal is the data value -1 converted from the binary digital signal to decimal data. 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. At this time, the signal conversion module can generate different adjustment signals based on adjustment signals of different bits, avoiding the correspondence between the digital signal and the circuit setting, so that the number of bits of the digital signal to be converted can be continuously increased, thereby improving the resolution of the digital-to-analog conversion structure.

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

[0081] Specifically, a write operation is performed in response to the adjustment signal 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 the digital signal, the adjustment signal includes an adjustment pulse, and the number of adjustment pulses in the adjustment signal is 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 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 impedance values ​​of the impedance adjustment unit.

[0084] In some embodiments, the impedance value of the impedance adjustment unit is linearly correlated with the number of adjustment pulses in the adjustment signal. Based on the above description, it can be seen that the number of adjustment pulses in the adjustment signal is linearly correlated with the digital signal, so that the impedance value of the impedance adjustment unit is linearly correlated with the digital signal, and the change of the same digital signal corresponds to the change of the impedance value of the same impedance adjustment unit, thereby improving the accuracy of digital-to-analog conversion. Step 503, output an analog signal based on the impedance value of the impedance adjustment unit.

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

[0086] In some embodiments, the read operation includes providing a reference current, and the signal generating unit 120 outputs an analog signal based on the reference current and the impedance value of the impedance adjusting 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 changed impedance value of the impedance adjustment unit 110. When the impedance value of the impedance adjustment unit 110 is stable, the analog signal level output by the signal generation unit 120 is stable. Therefore, for Figure 5 In the digital-to-analog conversion structure 100 shown, when a digital signal is input into the digital-to-analog conversion structure 100 , the impedance value of the impedance adjustment unit 110 needs to be stabilized before the analog signal is output, thereby completing the conversion from the digital signal to the analog signal.

[0088] The control method provided in this embodiment is applied to the digital-to-analog conversion structure provided in the above-mentioned embodiment. Through the device properties of the impedance adjustment unit, the resistance value of the impedance adjustment unit changes with the change of the adjustment signal, and the adjustment signal is generated corresponding to the digital signal, thereby avoiding the correspondence between the digital signal and the circuit setting, so that the number of bits of the digital signal to be converted can be continuously increased, thereby improving the resolution of the digital-to-analog conversion structure.

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

[0090] refer to Fig. 9 , Fig. 9 A schematic flow chart corresponding to each step in the control method including switching signal control provided in this embodiment.

[0091] Before executing step 501 , the method further includes step 510 of receiving a switching signal and performing a write operation based on the switching signal.

[0092] refer to Figure 6 and Figure 7 When the switching signal controls the control end of the control switch 301 to be electrically connected to the first selection end, the signal conversion module 101 is connected to the impedance adjustment unit 110 through the control switch 301, and 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.

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

[0094] After executing step 502 and before executing step 503, the method further includes step 520 of receiving a switching signal and performing a reading operation based on the switching signal.

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

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

[0097] By introducing the switching signal, the digital-to-analog conversion structure 100 can complete the conversion of the digital signal to the analog signal only by controlling the control switch 301 , which has a simple structure and low cost.

[0098] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, please refer to the detailed description of other embodiments above, and will not be repeated here.

[0099] The basic concepts have been described above. Obviously, for those skilled in the art, the above detailed disclosure is only for example and does not constitute a limitation of the present application. Although not explicitly stated herein, those skilled in the art may make various modifications, improvements and amendments to the present application. Such modifications, improvements and amendments are suggested in the present application, so such modifications, improvements and amendments still belong to the spirit and scope of the exemplary embodiments of the present application.

[0100] The above is a detailed introduction to a digital-to-analog conversion structure and control method provided in an embodiment of the present application. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method of the present application and its core idea; at the same time, for technical personnel in this field, according to the idea of ​​the present application, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A digital-to-analog conversion structure, characterized in that: include: The signal conversion module is configured to: receive a digital signal and output a regulation signal based on the digital signal; 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; The signal generating unit is connected to the impedance adjusting unit and is configured to output an analog signal based on the impedance value of the impedance adjusting unit.

2. The digital-to-analog conversion structure according to claim 1, characterized in that: The regulating signal includes regulating pulses; the change of the impedance value is in response to the change of the number of the regulating pulses or the change of the duty cycle of the regulating signal; If the change in the impedance value is in response to a change in the number of the adjustment pulses, the signal conversion module includes a first pulse generating circuit configured to: receive the digital signal, and generate the adjustment signal based on the digital signal, wherein the number of the adjustment pulses in the adjustment signal is the number corresponding to the digital signal; If the change in the impedance value responds to the change in the duty cycle of the adjustment signal, the signal conversion module includes a second pulse generating circuit, which is configured to: receive the digital signal and generate the adjustment signal based on the digital signal, and the duty cycle of the adjustment signal is the duty cycle corresponding to the digital signal.

3. The digital-to-analog conversion structure according to claim 2, characterized in that: The impedance value is linearly related to the number of the modulation pulses.

4. The digital-to-analog conversion structure according to claim 1, characterized in that: 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.

5. The digital-to-analog conversion structure according to claim 4, characterized in that: The impedance adjustment unit includes a phase change memory unit or a resistive change memory unit.

6. The digital-to-analog conversion structure according to claim 1, characterized in that: The signal generating 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 adjusting unit; the signal generating unit includes: an operational amplifier, a positive phase input terminal for receiving the reference current and connected to the first end of the impedance adjusting unit, a negative phase input terminal grounded, and an output terminal for outputting the analog signal.

7. The digital-to-analog conversion structure according to claim 1, characterized in that: The signal output module also includes a control unit configured to: receive a switching signal, and control the impedance adjustment unit to obtain the adjustment signal based on the switching signal, or control the signal generation unit to output the analog signal.

8. The digital-to-analog conversion structure according to claim 7, characterized in that: The control unit comprises a control switch, a first selection end is connected to the output end of the signal conversion module, a second selection end is connected to the output end of the signal generation unit, and a control end is connected to the impedance adjustment unit; The control switch is configured to: based on the switching signal, control the control end to be electrically connected to the first selection end or the second selection end; When the control switch controls the control terminal to be electrically connected to the first selection terminal 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 generating unit outputs an analog signal based on the impedance value of the impedance adjusting unit.

9. A control method for a digital-to-analog conversion structure according to any one of claims 1 to 8, characterized in that: include: Acquire a digital signal, and output a conditioning signal based on the digital signal; performing a write operation in response to the adjustment signal to adjust the impedance value of the impedance adjustment unit; A read operation is performed to output an analog signal based on the impedance value of the impedance adjustment unit.

10. The control method according to claim 9, characterized in that: The write operation includes: The signal conversion module outputs the adjustment signal based on the digital signal, the adjustment signal includes adjustment pulses, and the number of the adjustment pulses in the adjustment signal is the number corresponding to the digital signal; The impedance adjustment unit responds to the adjustment pulse in the adjustment signal and gradually changes the impedance value based on each of the adjustment pulses; The reading operation includes: providing a reference current; and a signal generating unit outputting an analog signal based on the reference current and an impedance value of the impedance adjusting unit.

11. The control method according to claim 9 or 10, characterized in that: Also includes: receiving a switching signal; Switching is performed between the write operation and the read operation based on the switch signal.

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