Dac device with current source measurement mechanism and current source measurement method thereof

Abstract

The present invention provides a digital-to-analog conversion device with a current source measurement mechanism. A digital-to-analog conversion circuit sequentially sets one of the thermometer-controlled current sources as a starting current source, and operates corresponding to two specific input code words included in an input digital signal to generate an output analog signal. The two specific input code words make the output analog signal opposite in sign and substantially the same in absolute value. An echo transmission circuit processes the output analog signal to generate an echo signal. An echo cancellation circuit processes the input digital signal according to echo cancellation coefficients to generate an echo cancellation signal, and receives an error signal to converge the echo cancellation coefficients. A current computation circuit generates a convergence coefficient statistic value and performs computation with a preset inverse matrix to generate current amounts of the thermometer-controlled current sources. An error computation circuit subtracts the echo cancellation signal from the echo signal to generate an error signal.

Description

Technical Field

[0001] This invention relates to digital-to-analog conversion technology, and more particularly to a digital-to-analog conversion device with a current source measurement mechanism and a current source measurement method thereof. Background Technology

[0002] A digital-to-analog converter (DAC) is a crucial component that converts signals from digital to analog form. DACs can generate analog signals of varying magnitudes by multiplying different digital codes by corresponding conversion gain values.

[0003] However, for current-output type digital-to-analog converters, process drift will cause non-ideal deviations in the amplitude and shape of the output. Among these, the amplitude deviation will seriously affect system performance. Summary of the Invention

[0004] In view of the problems of the prior art, one object of the present invention is to provide a digital-to-analog converter with a current source measurement mechanism and a current source measurement method thereof, so as to improve the prior art.

[0005] This invention includes a digital-to-analog converter with a current source measurement mechanism, comprising: a digital-to-analog converter circuit, an echo transmission circuit, an echo cancellation circuit, a current calculation circuit, and an error calculation circuit. The digital-to-analog converter circuit includes multiple thermometer-controlled current sources, each sequentially configured as a starting current source to operate corresponding to two specific input codewords included in the input digital signal. It generates an output analog signal based on the total current of the thermometer-controlled current sources. The two specific input codewords control the thermometer control operation state of each thermometer-controlled current source to one of a first current output state and a second current output state, and the two specific input codewords cause the output analog signal to have opposite signs and substantially the same absolute value. The echo transmission circuit processes the output analog signal to generate an echo signal. The echo cancellation circuit processes the input digital signal according to a set of echo cancellation coefficients to generate an echo cancellation signal and continuously receives error signals to converge the set of echo cancellation coefficients. The current calculation circuit statistically analyzes the converged echo cancellation coefficients to generate multiple convergence coefficient statistics for the number of thermometer-controlled current sources. These statistics are then used to calculate the current of each thermometer-controlled current source by comparing them with a preset inverse matrix. The preset matrix, which is the inverse of the preset matrix, reflects the state difference segments and identical state segments of two specific input codewords for different thermometer-controlled current sources as the initial current sources. The error calculation circuit subtracts the echo signal from the echo cancellation signal to generate an error signal.

[0006] The present invention further includes a current source measurement method applied in a digital-to-analog converter, comprising: a digital-to-analog converter circuit including multiple thermometer-controlled current sources, sequentially setting one of the thermometer-controlled current sources as a starting current source to operate corresponding to two specific input codewords included in the input digital signal, to generate an output analog signal based on the total current of the thermometer-controlled current sources, wherein the two specific input codewords control the thermometer control operation state of each thermometer-controlled current source to one of a first current output state and a second current output state, and the two specific input codewords cause the positive and negative signs of the output analog signal to be opposite and the absolute values ​​to be substantially the same; an echo transmission circuit processes the output analog signal to generate an echo signal; and an echo cancellation circuit... A set of echo cancellation coefficients processes the input digital signal to generate an echo cancellation signal, and continuously receives error signals to converge the set of echo cancellation coefficients. The current calculation circuit statistically analyzes the converged set of echo cancellation coefficients to generate multiple convergence coefficient statistical values ​​corresponding to the number of thermometer-controlled current sources. The convergence coefficient statistical values ​​are then calculated with a preset inverse matrix to generate the current amount of each thermometer-controlled current source. The preset matrix, which is the opposite of the preset inverse matrix, reflects the state difference segment and the same state segment of the thermometer-controlled current source corresponding to two specific input codewords when different thermometer-controlled current sources are used as the starting current source. The error calculation circuit subtracts the echo signal from the echo cancellation signal to generate an error signal.

[0007] The features, implementation, and effects of the present invention are described in detail below with reference to the accompanying drawings. Attached Figure Description

[0008] Figure 1 A block diagram of a digital-to-analog converter with a current source measurement mechanism is shown in one embodiment of the present invention;

[0009] Figure 2 A circuit diagram of a digital-to-analog converter circuit according to an embodiment of the present invention is shown;

[0010] Figure 3 A schematic diagram of the operation of a thermometer-controlled current source according to an embodiment of the present invention is shown;

[0011] Figure 4 This diagram illustrates the relationship between the convergence coefficient statistics, the preset matrix, and the current quantities of each thermometer-controlled current source in one embodiment of the present invention.

[0012] Figure 5 A schematic diagram of a preset inverse matrix is ​​shown in one embodiment of the present invention; and

[0013] Figure 6 A flowchart of a current source measurement method according to an embodiment of the present invention is shown.

[0014] Explanation of reference numerals in the attached figures:

[0015] 100: Digital-to-analog converter; 110: Digital-to-analog converter circuit; 120: Echo transmission circuit

[0016] 130: Echo cancellation circuit; 140: Current calculation circuit; 150: Error calculation circuit

[0017] 190: Echo response circuit; 195: Analog-to-digital conversion circuit; 200, 210: Switching circuit.

[0018] 600: Current source measurement method; S610~S650: Procedure; ADM: Preset inverse matrix

[0019]

[0020] Detailed Implementation

[0021] One object of this invention is to provide a digital-to-analog converter (DAC) with a current source measurement mechanism. This device utilizes two specific input codewords to cause the DAC circuit to output analog signals with opposite positive and negative values ​​but essentially the same absolute value. This allows the echo cancellation circuit to converge its coefficients, and the current calculation circuit further calculates the current of the thermometer-controlled current source based on the converged coefficients. The DAC can then set its activation sequence according to the relative relationship of the current of the thermometer-controlled current source, thereby improving the linearity of the DAC conversion.

[0022] Please refer to Figure 1 . Figure 1 A block diagram of a digital-to-analog converter 100 with a current source measurement mechanism according to an embodiment of the present invention is shown. The digital-to-analog converter 100 includes: a digital-to-analog conversion circuit 110, an echo transmission circuit 120, an echo cancellation circuit 130, a current calculation circuit 140, and an error calculation circuit 150.

[0023] The digital-to-analog converter circuit 110 is configured to receive an input digital signal IS having an input codeword from a signal source SS. In one embodiment, the signal source SS is, for example, but not limited to, a transmission circuit (TX) in a communication system.

[0024] Please refer to the following at the same time Figure 2 . Figure 2 A circuit diagram of a digital-to-analog converter circuit 110 according to an embodiment of the present invention is shown.

[0025] The digital-to-analog converter circuit 110 includes multiple current sources, including multiple thermometer-controlled current sources T01 to T31 (some omitted in the figure) and multiple binary-controlled current sources B1 to B4. The input codeword of the input digital signal IS controls the operating state of each current source to one of a first current output state and a second current output state, and generates an output analog signal OAS based on the total current of the current sources. The first current output state and the second current output state output currents of opposite polarities but equal magnitudes.

[0026] In one embodiment, the input codeword of the input digital signal IS includes multiple thermometer codes TC to control current sources T01 to T31, and each current source T01 to T31, under ideal conditions, corresponds to an output of 1 / 2 unit of current. In one embodiment, the thermometer codes TC control the switching circuit 200 corresponding to the current sources T01 to T31, so that the current sources T01 to T31 are electrically coupled to different current output paths through the switching circuit 200, for example... Figure 2 The solid line path and the dashed line path shown are used to operate in one of the first current output state and the second current output state.

[0027] One thermometer code A will control 2A-1 thermometer-controlled current sources in 2A-1 combinations. In this embodiment, A is 5. Therefore, 5 thermometer codes TC will control 31 thermometer-controlled current sources CA to CO in 32 combinations.

[0028] In operation, when the thermometer code changes sequentially from (00000), (00001), ... (11111), the current sources T01 to T31 switch their operating states sequentially, just like the thermometer. If current source T01 is used as the starting current source, then current sources T01 to T31 will sequentially switch from the second current output state to the first current output state, until all current sources T01 to T31 are in the first current output state.

[0029] In one embodiment, the input codeword of the input digital signal IS further includes multiple binary codes BC to control current sources B1 to B4, with each current source B1 to B4 corresponding to output current of 1 / 4 unit, 1 / 8 unit, 1 / 16 unit, and 1 / 32 unit, respectively. In one embodiment, the binary code BC controls the switching circuit 210 corresponding to the current sources B1 to B4, so that the current sources B1 to B4 are electrically coupled to different current output paths through the switching circuit 210, for example... Figure 2 The solid line path and the dashed line path shown are used to operate in one of the first current output state and the second current output state.

[0030] B binary codes BC will control B binary controlled current sources in 2B combinations. In this embodiment, B is 4. Therefore, 4 binary codes BC will control 4 binary controlled current sources B1 to B4 in 16 combinations.

[0031] In operation, when the binary code is switched sequentially from (0000), (0001), ... (1111), current source B1 is in the second and first current output states respectively when the highest bit is 0 and 1, current source B2 is in the second and first current output states respectively when the second highest bit is 0 and 1, current source B3 is in the second and first current output states respectively when the second lowest bit is 0 and 1, and current source B4 is in the second and first current output states respectively when the lowest bit is 0 and 1.

[0032] Therefore, through the control of the switching circuit 200 by the thermometer code TC and the control of the switching circuit 210 by the binary code BC, the digital-to-analog converter 110 can generate an output analog signal OAS from the total current of the current source.

[0033] The echo transmission circuit 120 is configured to process the output analog signal OAS to generate an echo signal ES. In one embodiment, the echo transmission circuit 120 includes an echo response circuit 190 and an analog-to-digital converter circuit 195. The echo response circuit 190 is configured to perform echo response processing on the output analog signal OAS, and the analog-to-digital converter circuit 195 further performs analog-to-digital conversion processing to generate the echo signal ES. In one embodiment, the echo transmission circuit 120 may also optionally include, for example, but not limited to, a digital low-pass filter or other digital signal processing circuitry (not shown) to further digitally process the echo signal ES.

[0034] The echo cancellation circuit 130 is configured to process the error signal DIS according to a set of echo cancellation coefficients CEC to generate an echo cancellation signal ECS. It should be noted that, in one embodiment, the echo cancellation circuit 130 may be shared with the receiving circuit (RX) in a communication system to cancel echoes fed into the receiving circuit from the transmitting circuit.

[0035] The current calculation circuit 140 performs statistical calculations based on the echo cancellation coefficient CEC and generates the current quantities of each thermometer-controlled current source T01 to T31 accordingly. The joint operation of the digital-to-analog conversion circuit 110, the echo cancellation circuit 130, and the current calculation circuit 140 will be described below in this specification.

[0036] The error calculation circuit 150 is configured to subtract the echo signal ES from the echo cancellation signal ECS to generate the error signal DIS.

[0037] Due to process deviation, each current source in the digital-to-analog converter circuit 110 will generate a current deviation value, resulting in a slight deviation of 1 / 2 unit in the output current. To measure each current source, the digital-to-analog converter circuit 110 sequentially sets one of the thermometer-controlled current sources T01 to T31 as the starting current source and operates according to the two specific input codewords included in the corresponding input digital signal IS, so as to generate an output analog signal OAS based on the total current of the current sources.

[0038] These two specific input codes cause one of the thermometer-controlled current sources T01 to T31 to operate in either a first current output state or a second current output state, respectively, and cause the binary-controlled current sources B1 to B4 to have the same binary control operation state (e.g., both in the first current output state and the second current output state). These two specific input codes will further cause the output analog signal OAS to be opposite in sign and substantially the same in absolute value. It should be noted that the term "substantially" means that the absolute values ​​of the output analog signals OAS corresponding to the two specific input codes do not need to be exactly equal, but can have an error within a reasonable range.

[0039] For example, two specific input codewords can be (10101) and (01000), which will respectively make the total current of the output analog signal OAS +9 and -9 units.

[0040] Figure 2 The operating states of each current source corresponding to these two specific input codewords are shown, with the first current output state marked by a white box and the second current output state marked by a dark box.

[0041] If current source T01 is used as the initial current source, under the control of the input codeword (10101) with a total current of +9, current sources T01 to T25 are in the first current output state, current sources T26 to T31 are in the second current output state, and current sources B1 to B4 are in the second current output state. The total current corresponding to the output analog signal OAS will be +19 / 2 - 15 / 32 ≈ +9 units.

[0042] If current source T01 is used as the initial current source, under the control of the input code word (01000) corresponding to a total current of -9, current sources T01 to T07 are in the first current output state, current sources T08 to T31 are in the second current output state, and current sources B1 to B4 are in the second current output state. In this state, the total current corresponding to the output analog signal OAS will be approximately -17 / 2 - 15 / 32 ≈ -9 units.

[0043] The thermometer-controlled current sources T01 to T31 correspond to the two specific input codes mentioned above, including the state difference segments of current sources T08 to T25, and the state similar segments of current sources T01 to T07 and T26 to T31. Figure 2 In the text, sections with different states are marked with thick borders, and sections with the same states are marked with thin borders.

[0044] Please refer to Figure 3 . Figure 3 A schematic diagram of the operation of thermometer-controlled current sources T01 to T31 in one embodiment of the present invention is shown.

[0045] like Figure 3 As shown, based on the two specific input codewords mentioned above, the digital-to-analog converter circuit 110 can sequentially set one of the thermometer-controlled current sources T01 to T31 as the starting current source, corresponding to the two specific input codewords included in the input digital signal IS, to generate an output analog signal OAS based on the total current of the current source. Wherein, Figure 3 The first column indicates the operating status of thermometer-controlled current source T01 as the starting current source, the second column indicates the operating status of thermometer-controlled current source T02 as the starting current source, and so on, with the last column (column 31) indicating the operating status of thermometer-controlled current source T31 as the starting current source.

[0046] Under the operation of the digital-to-analog converter circuit 110, the echo cancellation circuit 130 continuously receives the error signal DIS to converge the echo cancellation coefficients CEC. In one embodiment, the echo cancellation circuit 130 converges the echo cancellation coefficients CEC based on the error signal DIS through, for example, but not limited to, a least square root mean square training procedure.

[0047] The current calculation circuit 140 statistically analyzes the convergence echo cancellation coefficient CEC to generate multiple convergence coefficient statistical values ​​corresponding to the number of thermometer-controlled current sources T01 to T31. These convergence coefficient statistical values ​​are then used to calculate the current amount of each thermometer-controlled current source T01 to T31 using a preset inverse matrix. The preset matrix, which is the opposite of the preset inverse matrix, reflects the state difference segments and state similarity segments of two specific input codewords for different thermometer-controlled current sources T01 to T31 as initial current sources.

[0048] Please refer to Figure 4 . Figure 4 The diagram illustrates the relationship between the convergence coefficient statistics C01 to C31, the preset matrix DM, and the current quantities M01 to M31 of each thermometer-controlled current source T01 to T31 in one embodiment of the present invention.

[0049] In one embodiment, the echo cancellation circuit 130 generates multiple convergence coefficient groups corresponding to the number of thermometer-controlled current sources, each including multiple convergence coefficients. The current calculation circuit 140 further takes the absolute value of the convergence coefficients in each convergence coefficient group and adds them together to generate a convergence coefficient statistical value.

[0050] For example, when current source T01 is used as the initial current source, the digital-to-analog converter circuit 110 continuously generates an output analog signal OAS, which in turn causes the echo cancellation circuit 130 to continuously receive the error signal DIS to converge the echo cancellation coefficient CEC, generating a convergence coefficient group that includes multiple convergence coefficients. The current calculation circuit 140 further takes the absolute value of the convergence coefficients in this convergence coefficient group and adds them together to generate... Figure 4 The convergence coefficient statistic C01 in the figure.

[0051] Next, with current source T02 as the starting current source, echo cancellation circuit 130 and current calculation circuit 140 can perform the same operation to generate... Figure 4 The convergence coefficient statistic C02 is calculated. Similarly, when current source T31 is used as the initial current source, echo cancellation circuit 130 and current calculation circuit 140 can operate in the same way to generate... Figure 4 The convergence coefficient statistics are C31. Therefore, corresponding to the number of current sources T01 to T31, the current calculation circuit 140 can generate 31 convergence coefficient statistics C01 to C31.

[0052] In one embodiment, during the above-described calculation, the current calculation circuit 140 selects a subset of convergence coefficients from each convergence coefficient group, takes their absolute values, and then sums them to generate convergence coefficient statistics C01 to C31. The selected convergence coefficients can be, for example, but not limited to, those with relatively large values ​​among all convergence coefficients. In this way, the current calculation circuit 140 can not only reduce the computational load but also minimize noise interference.

[0053] Since the convergence process performed by the echo cancellation circuit 130 is based on values ​​with fixed heights (+9 and -9), all the corresponding amplitude information will fall onto the convergence coefficients. Furthermore, the information corresponding to the same state segment is a DC component and will be removed by a high-pass filter, leaving only the information corresponding to the state difference segment. Therefore, the convergence coefficient statistics C01 to C31 are equivalent to the result of multiplying the preset matrix DM by the current quantities M01 to M31 of each thermometer-controlled current source T01 to T31.

[0054] When the number of thermometer-controlled current sources is M, the preset matrix DM has a size of M×M. Each column of the preset matrix DM corresponds sequentially to the arrangement of thermometer-controlled current sources T01 to T31. The state difference segment and the state same segment corresponding to one of the thermometer-controlled current sources T01 to T31 as the initial current source respectively include multiple first elements with a value of 1 and multiple second elements with a value of 0. Figure 3 The same, in Figure 4 Sections with different states are marked with thick boxes, while sections with the same state are marked with thin boxes.

[0055] Therefore, after the convergence coefficient statistical values ​​C01 to C31 are obtained through the operation of the echo cancellation circuit 130 and the current calculation circuit 140, the current calculation circuit 140 further calculates according to the preset inverse matrix corresponding to the preset matrix DM to generate the current M01 to M31 of each thermometer-controlled current source T01 to T31.

[0056] Please refer to Figure 5 . Figure 5 A schematic diagram of a preset inverse matrix ADM is shown in one embodiment of the present invention.

[0057] like Figure 5 As shown, the matrix elements of the preset inverse matrix ADM corresponding to the preset matrix DM have only two values: +7 and -11. The matrix element corresponding to +7 is marked with a blank box, and the matrix element corresponding to -11 is marked with a grid-filled box. It should be noted that setting two different specific input codewords will generate preset inverse matrices ADM with different matrix elements. The matrix element values ​​of the preset inverse matrix ADM are not limited to these.

[0058] Therefore, through the operation of the echo cancellation circuit 130 and the current calculation circuit 140, the current M01 to M31 of each thermometer-controlled current source T01 to T31 can be determined.

[0059] It should be noted that in the above embodiments, the echo cancellation circuit 130 and the current calculation circuit 140 are described as two independent circuits. However, in other embodiments, the echo cancellation circuit 130 and the current calculation circuit 140 may be selectively integrated into a single circuit. Furthermore, in the above embodiments, the number of current sources and the magnitude of the current are merely examples. In other embodiments, the number of current sources and the magnitude of the current may vary depending on the requirements. The present invention is not limited thereto.

[0060] In one embodiment, the digital-to-analog converter circuit 110 is further configured to calculate the average current of the thermometer-controlled current sources T01 to T31 by, for example, but not limited to, a built-in control circuit, and to sort the multiple current deviation values ​​corresponding to the thermometer-controlled current sources T01 to T31 according to the average current and the current of each thermometer-controlled current source T01 to T31 to generate an activation sequence.

[0061] For example, the current deviation value can be divided into multiple current deviation value groups according to the opening sequence. Each two adjacent current deviation value groups are opposite in sign, so that they can be interleaved and canceled out when accumulated according to the opening sequence, thereby maintaining the total absolute value of the current deviation value not greater than half of the maximum absolute value among the current deviation values.

[0062] In operation mode, the digital-to-analog converter circuit 110 can control the thermometer-controlled current sources T01 to T31 to turn on in the set turn-on sequence according to the thermometer code TC included in the input digital signal IS.

[0063] It should be noted that the above-described activation sequence is merely an example. In different embodiments, the digital-to-analog converter circuit 110 can set the activation sequence in different ways according to the current M01 to M31 of the thermometer-controlled current sources T01 to T31. The present invention is not limited thereto.

[0064] Therefore, the digital-to-analog converter of the present invention can use two specific input codewords to make the digital-to-analog converter output analog signals with opposite positive and negative values ​​and substantially the same absolute value, so that the echo cancellation circuit can converge the coefficients, and then the current calculation circuit can further calculate the current of the thermometer-controlled current source based on the converged coefficients. The digital-to-analog converter can further set the turn-on sequence according to the relative relationship of the current of the thermometer-controlled current source, thereby improving the linearity of the digital-to-analog conversion.

[0065] Please refer to the following at the same time Figure 6 . Figure 6 A flowchart of a current source measurement method 600 according to an embodiment of the present invention is shown.

[0066] In addition to the aforementioned device, the present invention also discloses a current source measurement method 600, applicable to, for example, but not limited to, [various applications]. Figure 1 In the analog-to-digital converter 100, an embodiment of the current source measurement method 600 is as follows: Figure 6 As shown, it includes the following steps.

[0067] In step S610: The digital-to-analog converter circuit 110, which includes multiple thermometer-controlled current sources T01 to T31, sequentially sets one of the thermometer-controlled current sources T01 to T31 as the starting current source. It operates according to the two specific input codes included in the input digital signal IS to generate an output analog signal OAS based on the total current of the thermometer-controlled current sources T01 to T31. The two specific input codes control the thermometer control operation state of each thermometer-controlled current source T01 to T31 to be one of the first current output state and the second current output state. The two specific input codes make the positive and negative signs of the output analog signal OAS opposite and the absolute values ​​substantially the same.

[0068] In step S620: The output analog signal OAS is processed by the echo transmission circuit 120 to generate the echo signal ES.

[0069] In step S630: The echo cancellation circuit 130 processes the input digital signal IS according to a set of echo cancellation coefficients CEC to generate an echo cancellation signal ECS, and continuously receives the error signal DIS to converge the set of echo cancellation coefficients CEC.

[0070] In step S640: The current calculation circuit 140 performs statistics on the converged echo cancellation coefficient CEC of the group to generate multiple convergence coefficient statistical values ​​C01 to C31 corresponding to the number of thermometer-controlled current sources T01 to T31. Then, the convergence coefficient statistical values ​​C01 to C31 are calculated with the preset inverse matrix ADM to generate the current M01 to M31 of each thermometer-controlled current source C01 to C31.

[0071] In step S650: The error calculation circuit 150 subtracts the echo signal ES from the echo cancellation signal ECS to generate the error signal DIS.

[0072] It should be noted that the above-described implementation is merely an example. In other embodiments, those skilled in the art can make modifications and variations without departing from the spirit of the invention.

[0073] In summary, the digital-to-analog converter with a current source measurement mechanism and its current source measurement method in this invention utilize two specific input codewords to cause the digital-to-analog converter circuit to output analog signals with opposite positive and negative values ​​but essentially the same absolute value. This allows the echo cancellation circuit to converge its coefficients, and the current calculation circuit further calculates the current of the thermometer-controlled current source based on the converged coefficients. Furthermore, the digital-to-analog converter can set the activation sequence according to the relative relationship of the current of the thermometer-controlled current source, thereby improving the linearity of the digital-to-analog conversion.

[0074] While the embodiments of the present invention have been described above, these embodiments are not intended to limit the present invention. Those skilled in the art can make changes to the technical features of the present invention based on the explicit or implicit content of the present invention, and these changes may all fall within the scope of patent protection claimed by the present invention. In other words, the scope of patent protection of the present invention shall be determined by the claims.

Claims

1. A digital-to-analog converter with a current source measurement mechanism, comprising: A digital-to-analog converter circuit includes multiple thermometer-controlled current sources. Each of the multiple thermometer-controlled current sources is sequentially configured as a starting current source to operate in accordance with two specific input codes included in an input digital signal. The circuit generates an output analog signal based on a total current from the multiple thermometer-controlled current sources. The two specific input codes control the thermometer control operation state of each of the multiple thermometer-controlled current sources to one of a first current output state and a second current output state. The two specific input codes make the positive and negative signs of the output analog signal opposite and the absolute values ​​substantially the same. An echo transmission circuit processes the output analog signal to generate an echo signal; An echo cancellation circuit processes the input digital signal according to a set of echo cancellation coefficients to generate an echo cancellation signal, and continuously receives an error signal to converge the set of echo cancellation coefficients. A current calculation circuit statistically analyzes the converged set of echo cancellation coefficients to generate multiple convergence coefficient statistical values ​​corresponding to the number of multiple thermometer-controlled current sources. These multiple convergence coefficient statistical values ​​are then calculated with a preset inverse matrix to generate a current quantity for each of the multiple thermometer-controlled current sources. The preset matrix, which is opposite to the preset inverse matrix, reflects the state difference segment and the state same segment of the multiple thermometer-controlled current sources corresponding to the two specific input codewords when different multiple thermometer-controlled current sources are used as the initial current sources. as well as An error calculation circuit is used to subtract the echo signal from the echo cancellation signal to generate the error signal.

2. The digital-to-analog conversion device of claim 1, wherein, The echo cancellation circuit generates multiple convergence coefficient groups, each containing multiple convergence coefficients, corresponding to the number of thermometer-controlled current sources. The current calculation circuit further takes the absolute value of each of the multiple convergence coefficient groups and adds them together to generate the multiple convergence coefficient statistical values.

3. The digital-to-analog converter according to claim 2, characterized in that, The current calculation circuit selects the absolute values ​​of some of the multiple convergence coefficients with relatively large values ​​from each of the multiple convergence coefficient groups and then adds them together to generate the statistical values ​​of the multiple convergence coefficients.

4. The digital-to-analog conversion device of claim 1, wherein, The number of the plurality of thermometer-controlled current sources is M, the size of the preset matrix is ​​M×M, each column of the preset matrix corresponds to an arrangement of the plurality of thermometer-controlled current sources, and sequentially corresponds to the state difference segment when one of the plurality of thermometer-controlled current sources is used as the starting current source, and the state same segment includes a plurality of first elements with a value of 1 and a plurality of second elements with a value of 0.

5. The digital-to-analog conversion device of claim 1, wherein, The digital-to-analog converter circuit further includes multiple binary controlled current sources. The digital-to-analog converter circuit enables the multiple binary controlled current sources to have the same binary control operation state according to the two specific input code words, so as to generate the output analog signal according to the multiple thermometer controlled current sources and the total current of the multiple binary controlled current sources.

6. The digital-to-analog converter according to claim 1, characterized in that, The digital-to-analog converter circuit is further configured to calculate an average current of the plurality of thermometer-controlled current sources, and to extract a plurality of current deviation values ​​corresponding to the plurality of thermometer-controlled current sources based on the average current and the current of each of the plurality of thermometer-controlled current sources, and to perform a sorting procedure to generate an activation sequence, thereby causing the plurality of thermometer-controlled current sources to activate in the activation sequence according to the plurality of thermometer codes included in the input digital signal in an operating mode.

7. A current source measurement method, applied in a digital-to-analog converter, comprising: A digital-to-analog converter circuit comprising multiple thermometer-controlled current sources sequentially sets one of the multiple thermometer-controlled current sources as a starting current source and operates according to two specific input codes included in an input digital signal, so as to generate an output analog signal based on a total current of the multiple thermometer-controlled current sources. The two specific input codes control the thermometer control operation state of each of the multiple thermometer-controlled current sources to one of a first current output state and a second current output state, and the two specific input codes make the positive and negative signs of the output analog signal opposite and the absolute values ​​substantially the same. An echo transmission circuit processes the output analog signal to generate an echo signal; An echo cancellation circuit processes the input digital signal according to a set of echo cancellation coefficients to generate an echo cancellation signal, and continuously receives an error signal to converge the set of echo cancellation coefficients. A current calculation circuit statistically analyzes the converged set of echo cancellation coefficients to generate multiple convergence coefficient statistical values ​​corresponding to the number of multiple thermometer-controlled current sources. These multiple convergence coefficient statistical values ​​are then calculated with a preset inverse matrix to generate a current quantity for each of the multiple thermometer-controlled current sources. The preset matrix, which is the opposite of the preset inverse matrix, reflects the state difference segment and the state same segment of the multiple thermometer-controlled current sources corresponding to the two specific input codewords when different multiple thermometer-controlled current sources are used as the starting current sources. as well as An error calculation circuit is used to subtract the echo cancellation signal from the echo signal to generate the error signal.

8. The current source measurement method according to claim 7, characterized in that, Also includes: The echo cancellation circuit generates multiple convergence coefficient groups, each containing multiple convergence coefficients, corresponding to the number of the multiple thermometer-controlled current sources. as well as The current calculation circuit further takes the absolute values ​​of the multiple convergence coefficients in each of the multiple convergence coefficient groups and then adds them together to generate the multiple convergence coefficient statistical values.

9. The current source measurement method of claim 7, wherein, The number of the plurality of thermometer-controlled current sources is M, the size of the preset matrix is ​​M×M, each column of the preset matrix corresponds to an arrangement of the plurality of thermometer-controlled current sources, and sequentially corresponds to the state difference segment when one of the plurality of thermometer-controlled current sources is used as the starting current source, and the state same segment includes a plurality of first elements with a value of 1 and a plurality of second elements with a value of 0.

10. The current source measurement method according to claim 7, characterized in that, Also includes: The digital-to-analog converter circuit is further configured to calculate an average current of the plurality of thermometer-controlled current sources, and to extract a plurality of current deviation values ​​corresponding to the plurality of thermometer-controlled current sources based on the average current and the current of each of the plurality of thermometer-controlled current sources, and to perform a sorting procedure to generate an activation sequence, thereby causing the plurality of thermometer-controlled current sources to activate in the activation sequence according to the plurality of thermometer codes included in the input digital signal in an operating mode.

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