A current steering digital-to-analog converter with random rotation selection function

Abstract

The application relates to a current steering digital-to-analog converter with a random rotation selection function, based on the division of segment decoding high, medium and low bits of a digital signal, a random rotation module and a synthesis latch module are introduced to form a random rotation selection module, the high bit thermometer code control signal and the medium bit thermometer code control signal after decoding are respectively subjected to random rotation shift transformation update by the random rotation module, and then the synthesis latch module executes sampling splicing according to the same clock edge and the updated control signals and the delayed low bit control signal, thereby driving a current source array to generate a differential current signal output; the design scheme can improve the spectral performance of the output signal, the current source mismatch error is uniformly diffused in the frequency domain due to the disturbance mechanism, the harmonic peak value is obviously reduced, the spur-free dynamic range is improved, and the random operation design makes the spur distribution of the output signal smoother.

Description

Technical Field

[0001] This invention relates to a current-rudder type digital-to-analog converter and system with random rotation selection function, belonging to the field of mixed-signal integrated circuit technology. Background Technology

[0002] Current-driven analog-to-digital converters (ADCs) offer advantages such as high speed and wide bandwidth, and are commonly used in communication and testing equipment. However, their dynamic performance is susceptible to mismatch in the current source units. Traditional thermometer decoding processes signals in units with a fixed lighting sequence. Over long-term operation, this can exacerbate the bias of certain units, causing the mismatch to manifest as stable harmonics in the frequency spectrum, thus limiting the spurious-free dynamic range. Consequently, existing ADC technologies suffer from low operating efficiency. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a current-rudder type digital-to-analog converter with random rotation selection function, which can reduce the impact of current source unit mismatch on dynamic performance.

[0004] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: The present invention designs a current-rudder type digital-to-analog converter with random rotation selection function, including an input register, a segmented decoding module, a delay unit, a random rotation selection module, and a current source array, wherein the random rotation selection module includes a random rotation module and a synthesis latch module;

[0005] The input register receives a digital signal of the target bit width, latches it, and divides it into high-bit, middle-bit, and low-bit signals. The high-bit and middle-bit signals are first decoded by a segmented decoding module under a preset target clock cycle to generate high-bit and middle-bit thermometer code control signals, respectively. These signals are then updated by a random rotation module through random rotation and shift transformation and sent to the synthesis latch module. Simultaneously, a delay unit performs a delay on the low-bit signal under a preset target clock cycle to form a low-bit control signal, which is sent to the synthesis latch module. The synthesis latch module samples the high-bit, middle-bit, and low-bit thermometer code control signals at the same clock edge and splices them into a complete control signal. This complete control signal drives a current source array to generate a differential current signal for output.

[0006] As a preferred technical solution of the present invention: the random rotation module includes two sets of linear feedback shift registers corresponding to the high-level thermometer code control signal and the mid-level thermometer code control signal, respectively. For the linear feedback shift register corresponding to the high-level thermometer code control signal, the bits of the first bit width preset in the linear feedback shift register are used as the rotation control signal. The rotation control signal controls the cyclic shift stage of the barrel shift register. The barrel shifter receives the high-level thermometer code control signal and performs random rotation shift transformation update under the drive of the rotation control signal. The preset first bit width is equal to the bit width of the high-level signal.

[0007] Regarding the linear feedback shift register corresponding to the median thermometer code control signal, each bit of the preset second bit width in the linear feedback shift register is used as the rotation control signal. The rotation control signal controls the cyclic shift stage of the barrel shift register. The barrel shifter receives the median thermometer code control signal and performs random rotation shift transformation update under the drive of the rotation control signal. The preset second bit width is equal to the bit width of the median signal.

[0008] As a preferred technical solution of the present invention: the high-order signal has a bit width of 5 bits and the middle-order signal has a bit width of 3 bits. The random rotation module includes two sets of 32-bit linear feedback shift registers corresponding to the high-order thermometer code control signal and the middle-order thermometer code control signal, respectively. Among them, the 3rd, 10th, 17th, 24th and 31st bits of the linear feedback shift register are used as rotation control signals to control the cyclic shift stages in the barrel shifter with shift amounts of 1, 2, 4, 8 and 16, respectively. The barrel shifter receives the high-order thermometer code control signal and performs random rotation shift transformation update in a single clock cycle under the drive of the rotation control signal.

[0009] Regarding the linear feedback shift register corresponding to the median thermometer code control signal, bits 10, 20, and 30 in the linear feedback shift register are used as rotation control signals to control the cyclic shift stages in the barrel shifter with shift amounts of 1, 2, and 4, respectively. The barrel shifter receives the median thermometer code control signal and performs random rotation shift transformation updates within a single clock cycle under the drive of the rotation control signal.

[0010] As a preferred technical solution of the present invention: while the synthetic latch module outputs the spliced ​​complete control signal, it also outputs the high-level thermometer code control signal and the middle-level thermometer code control signal before the random rotation shift transformation update.

[0011] As a preferred embodiment of the present invention: the current source array includes a first equal-amplitude current source array, a second equal-amplitude current source array, and a weighted current source array, which respectively correspond to the high, middle, and low bits of the complete control signal. Under the control of the control signal of the corresponding bit in the complete control signal, each current source array switches the current to the positive output terminal or the reverse output terminal through its own differential switch, and connects to the positive output terminal of each current source array and the reverse output terminal of each current source array to output a differential current signal.

[0012] As a preferred technical solution of the present invention: based on a 31-bit high-level thermometer code control signal, a 7-bit mid-level thermometer code control signal, and a 4-bit low-level control signal, the first equal-amplitude current source array includes 31 128×I equal-amplitude current units, the second equal-amplitude current source array includes 7 16×I equal-amplitude current units, and the weighted current source array includes 4 binary weighted current units: 8×I weighted current unit, 4×I weighted current unit, 2×I weighted current unit, and 1×I weighted current unit.

[0013] As a preferred embodiment of the present invention, it further includes a clock driving circuit, which receives the clock signal CLK and provides clock driving signals to the input register and the random rotation module and the synthesis latch module in the random rotation selection module as the basis for operation.

[0014] As a preferred technical solution of the present invention: a 12-bit binary digital signal is received by an input register, latched and divided into a high-bit signal of 5 bits, a middle-bit signal of 3 bits, and a low-bit signal of 4 bits; the high-bit signal and the middle-bit signal are respectively decoded by a segmented decoding module to generate a 31-bit high-bit thermometer code control signal and a 7-bit middle-bit thermometer code control signal.

[0015] The current-rudder type digital-to-analog converter with random rotation selection function described in this invention has the following technical advantages compared with the prior art:

[0016] (1) This invention designs a current-rudder type digital-to-analog converter with random rotation selection function. Based on the segmented decoding of digital signals into high, middle and low bits, a random rotation selection module composed of a random rotation module and a synthesis latch module is introduced. The random rotation module performs random rotation shift transformation to update the decoded high-bit thermometer code control signal and the middle-bit thermometer code control signal respectively. Then, the synthesis latch module performs sampling and splicing on each updated control signal and the delayed low-bit control signal according to the same clock edge, thereby driving the current source array to generate differential current signal output. The design scheme can improve the spectral performance of the output signal. Moreover, due to the perturbation mechanism, the current source mismatch error is uniformly diffused in the frequency domain, which significantly reduces the harmonic peak value and improves the spurious-free dynamic range. In addition, the randomized operation design makes the spurious distribution of the output signal smoother.

[0017] (2) In the current-rudder type digital-to-analog converter with random rotation selection function designed in this invention, the high-order thermometer code control signal and the middle-order thermometer code control signal after decoding are introduced into the random rotation module for random rotation shift transformation and update. Under the premise of ensuring that the number of logic "1" remains unchanged, the position of them in the sequence is changed, thereby dispersing the use of the current source unit and reducing the harmonic accumulation caused by the mismatch of the fixed unit. Specifically for the high-order and middle-order, based on independent linear feedback shift registers, the barrel shifter is driven by the rotation control signal to achieve single-cycle combined rotation, with low hardware overhead. At the same time, a delay unit is set for the low-order to ensure that the high, middle and low signals are aligned on the same clock edge, which improves the spectral performance of the output signal and makes the spurious distribution of the output signal smoother. Attached Figure Description

[0018] Figure 1 This is a block diagram of the overall system structure of the current-rudder type digital-to-analog converter with random rotation selection function designed in this invention;

[0019] Figure 2 This is a schematic diagram of the workflow of the random rotation selection module designed in this invention;

[0020] Figure 3 This is an example diagram showing the rotation results of the thermometer code under different cycles in the design of this invention;

[0021] Figure 4 This is a schematic diagram illustrating the improvement in spurious-free dynamic range performance achieved by the present invention before and after adopting the random rotation selection mechanism. Detailed Implementation

[0022] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0023] This invention designs a current-controlled digital-to-analog converter with random rotation selection function, such as... Figure 1 As shown, the design includes an input register, a segmented decoding module, a delay unit, a random rotation selection module, a current source array, and a clock drive circuit. The random rotation selection module includes a random rotation module and a synthesis latch module. The clock drive circuit receives the clock signal CLK and provides clock drive signals to the input register and the random rotation module and synthesis latch module in the random rotation selection module as the basis for operation.

[0024] like Figure 1 As shown, in practical applications of digital-to-analog conversion, the input register receives the digital signal with the target bit width and, based on the clock drive signal, performs latching and divides it into high-bit, middle-bit, and low-bit signals. The high-bit and middle-bit signals are first decoded by the segmented decoding module under a preset target clock cycle to generate high-bit and middle-bit thermometer code control signals, respectively, which are then sent to the random rotation module. The random rotation module then performs random rotation shift transformation on the high-bit and middle-bit thermometer code control signals according to the clock drive signal and sends the updated signals to the synthesis latch module. Simultaneously, the delay unit performs a delay on the low-bit signal under a preset target clock cycle to form a low-bit control signal, which is then sent to the synthesis latch module.

[0025] Regarding the random rotation shift transformation update operation performed by the random rotation module, the random rotation module is specifically designed to include two sets of linear feedback shift registers corresponding to the high-level thermometer code control signal and the mid-level thermometer code control signal, respectively. In practical applications, for the linear feedback shift register corresponding to the high-level thermometer code control signal, the first bit width of the linear feedback shift register is preset as the rotation control signal. The rotation control signal controls the cyclic shift stage of the barrel shift register. The barrel shifter receives the high-level thermometer code control signal and, according to the clock drive signal, performs random rotation shift transformation updates under the drive of the rotation control signal. That is, for the high-level thermometer code control signal, the rotation shift is maintained... The number of logic "1"s remains unchanged while their position in the sequence is changed, where the first bit width is preset to be equal to the bit width of the high-order signal; for the linear feedback shift register corresponding to the median thermometer code control signal, the bits of the preset second bit width in the linear feedback shift register are used as rotation control signals, which control the cyclic shift stage of the barrel shift register. The barrel shifter receives the median thermometer code control signal and, according to the clock drive signal, performs random rotation shift transformation update under the drive of the rotation control signal. That is, for the median thermometer code control signal, the number of logic "1"s remains unchanged while their position in the sequence is changed, where the preset second bit width is equal to the bit width of the median signal.

[0026] In practical applications, further design considerations were made for the application of each linear feedback shift register. A bypass path was reserved in the synthesis latch module, allowing direct selection of the original thermometer code output, i.e., the control signal before the random rotation shift transformation update. Specifically, while outputting the complete concatenated control signal, the synthesis latch module also outputs the high-order thermometer code control signal and the mid-order thermometer code control signal before the random rotation shift transformation update. During the testing and verification phase, the difference between the perturbed and unperturbed outputs can be compared by switching modes; in normal operating mode, the low-order signal aligned with the rotation result and delay is used for driving.

[0027] The aforementioned decoding and random rotation shift transformation updates for the high-order, mid-order, and low-order signals are all completed within a preset target clock cycle. This ensures that the outputs of the high-order thermometer code control signal, mid-order thermometer code control signal, and low-order control signal are on the same clock edge. Therefore, the synthesis latch module samples the high-order, mid-order, and low-order control signals on the same clock edge according to the clock drive signal and splices them into a complete control signal. The complete control signal then drives the current source array to generate a differential current signal for output.

[0028] In practical applications, the specific design of the current source array includes a first equal-amplitude current source array, a second equal-amplitude current source array, and a weighted current source array, which correspond to the high, middle, and low bits of the complete control signal, respectively. Under the control of the control signal of the corresponding bit in the complete control signal, each current source array switches the current to the positive output terminal or the reverse output terminal through its own differential switch, and connects to the positive output terminal of each current source array and the reverse output terminal of each current source array to output a differential current signal.

[0029] Applying the above design to practical applications, such as processing 12-bit binary digital signals, involves receiving the 12-bit binary digital signal from the input register, latching and dividing it into the high 5 bits (D<11:7>), the middle 3 bits (D<6:4>), and the low 4 bits (D<3:0>).

[0030] Then, the high-order signals D<11:7> and D<6:4> are first decoded by the segmented decoding module in one clock cycle to generate a 31-bit high-order thermometer code control signal Tm<30:0> and a 7-bit middle-order thermometer code control signal Tu<6:0>, which are then sent to the random rotation module. The random rotation module, based on the clock drive signal, performs random rotation shift transformations on the high-order thermometer code control signal Tm<30:0> and the middle-order thermometer code control signal Tu<6:0> respectively, and then sends the updated signals to the synthesis latch module. Wherein, as... Figure 2As shown, the random rotation module includes two sets of 32-bit linear feedback shift registers corresponding to the high-level thermometer code control signal and the mid-level thermometer code control signal, respectively. Regarding the linear feedback shift register corresponding to the high-level thermometer code control signal, when the system powers on, the linear feedback shift register loads an initial seed and continuously shifts under the action of the clock, updating once per clock edge. The state change of the linear feedback shift register generates a pseudo-random sequence. Bits 3, 10, 17, 24, and 31 in the linear feedback shift register are used as rotation control signals to control the cyclic shift stages in the barrel shifter with shift amounts of 1, 2, 4, 8, and 16, respectively. That is, the barrel shifter operates from five cyclic shift stages. The shift units are connected in series, with shift steps of 1, 2, 4, 8, and 16 bits respectively. The rotation control signals correspond to the five rotation stages of the barrel shifter. The barrel shifter receives the high-level thermometer code control signal and performs random rotation shift transformations and updates within a single clock cycle under the drive of the rotation control signal. When the control bit is logic "1", the stage performs cyclic shift; when the control bit is logic "0", the sequence remains unchanged. In this way, combined rotations can be completed within one clock cycle, and the arrangement of the output results has a high degree of randomness. The output after five stages of processing has the same weight as the original sequence, but the arrangement position has changed. In this way, the same input weights will result in different arrangements in each clock cycle, making the use of the current source unit tend to be balanced in the long term.

[0031] like Figure 2 As shown, regarding the linear feedback shift register corresponding to the median thermometer code control signal, when the system powers on, the linear feedback shift register loads the initial seed and continuously shifts under the action of the clock, updating once per clock edge. The state change of the linear feedback shift register generates a pseudo-random sequence. Bits 10, 20, and 30 in the linear feedback shift register are used as rotation control signals to control the cyclic shift stages in the barrel shifter with shift amounts of 1, 2, and 4, respectively. The barrel shifter receives the median thermometer code control signal and performs random rotation shift transformation updates within a single clock cycle under the drive of the rotation control signal. That is, the rotation control signal obtained thereby drives the three-stage barrel shifter with step sizes of 1 bit, 2 bits, and 4 bits, respectively. Each stage determines whether to perform cyclic shift according to the rotation control signal. The final output changes in each clock cycle.

[0032] The two sets of linear feedback shift registers for the high-order and middle-order segments, respectively, operate independently without a fixed correlation, thus avoiding regular coupling between different segments during perturbation. Furthermore, in implementation, the output arrangement of the high-order and middle-order channels differs in each cycle, but the number of "1"s always matches the input weights, ensuring the validity of the thermometer code. Since the perturbation mechanism only changes the position of the "1"s, not their quantity, the control signals received by the subsequent current source array maintain the correct amplitude, while the order of cell usage is disrupted. This modular structure, implemented through registers, shifters, and selectors, has a shallow logic depth, enabling high-speed operation without introducing additional computational latency.

[0033] Since the number of low-order units in the circuit structure is limited and their amplitude differences are large, their uneven use has a relatively small impact on the overall dynamic performance. Therefore, for the processing of low-order segment signals, a rotational perturbation mechanism is not adopted, and maintaining the original binary decoding method is more reasonable. Simultaneously, to ensure the timing consistency of the high, middle, and low-order data, this invention directly sets a delay unit in the low-order segment path. Under the action of the system clock, the low-order segment digital signal is held in the delay unit for one clock cycle before being output, thus enabling the low-order control signal to enter the synthesis latch module at the same time as the perturbated middle and high-order thermometer code control signals. Specifically, the delay unit is composed of flip-flops, which reduces hardware costs and avoids inconsistencies between different segment signals during the synthesis stage. Therefore, during the above execution process, the delay unit performs a one-clock-cycle delay on the low-order signal, forming the lower 4 bits of the low-order control signal Bl<3:0>, which is sent to the synthesis latch module.

[0034] In the process described above, the high-order signal D<11:7> is decoded by the segmented decoding module to generate the 31-bit high-order thermometer code control signal Tm<30:0> (thermometer code). Specifically, the highest bit corresponds to 16 logic "1", the second highest bit corresponds to 8 logic "1", and the following bits correspond to 4, 2, and 1 logic "1" respectively. The thermometer code obtained by splicing these parts can directly drive the 31-unit current array. Furthermore, in practical applications, this original sequence is retained and used as an output for testing or backup scenarios.

[0035] Finally, the synthesis latch module samples the high-order thermometer code control signal, the middle-order thermometer code control signal, and the low-order control signal at the same clock edge according to the clock drive signal, and splices them into a complete control signal. The complete control signal drives the current source array to generate a differential current signal for output. In practical applications, the current source array includes a first equal-amplitude current source array, a second equal-amplitude current source array, and a weighted current source array, which correspond to the high-order, middle-order, and low-order parts of the complete control signal, respectively. Specifically, the first equal-amplitude current source array includes 31 128×I equal-amplitude current units. The design includes a second constant amplitude current source array consisting of seven 16×I constant amplitude current units and a weighted current source array consisting of four binary weighted current units: an 8×I weighted current unit, a 4×I weighted current unit, a 2×I weighted current unit, and a 1×I weighted current unit. Under the control of the corresponding bit control signal in the complete control signal, each current source array switches the current to the positive output terminal or the reverse output terminal through its own differential switch, and connects to the positive output terminal of each current source array as well as the reverse output terminal of each current source array, outputting differential current signals Ion and Iop.

[0036] like Figure 3As shown, the effect of random rotation selection can be intuitively demonstrated through the arrangement of the thermometer code. In the traditional structure, the input weight is a fixed value, and the corresponding number of logic "1"s always appear in the corresponding positions of the sequence, while other positions remain logic "0". For example, when the middle section D<6:4> is 011, the Tu<6:3> corresponding to D6 is 0, the Tu2 and 1 bits corresponding to D5 are 1, and the Tu0 corresponding to D4 is 1. When D<6:4> is 100, 101, 110, 111, the positions of the corresponding outputs of 1 and 0 are also fixed. When this distribution pattern causes the front-end current source to be repeatedly used, while the utilization rate of the back-end unit is extremely low, the mismatch error will manifest as obvious harmonics in the frequency spectrum. After adopting the random rotation selection mechanism of this invention, the arrangement of the thermometer code rotates cyclically while maintaining the number of logic "1"s. For example, when the middle segment D<6:4> is 011, and the three taps are 010, the 4-bit thermometer code corresponding to D6, the 2-bit code corresponding to D5, and the 1-bit code corresponding to D4 are rotated 2 bits to the left. Thus, the positions of the 4-bit thermometer code corresponding to D6 become U6, U5, U1, and U0; the positions of the 2-bit thermometer code corresponding to D5 become U4 and U3; and the position of the 1-bit thermometer code corresponding to D4 becomes U2, resulting in an output of 0011100. Each time the middle segment D<6:4> changes, the three taps also change randomly, and the output code value rotates randomly. For example, when D<6:4> is 100, 101, 110, or 111, the random change of the three taps might rotate the code value by 0, 1, 6, or 3 bits. In this way, all current source units distribute the workload evenly during long-term operation, effectively dispersing mismatch errors. Examples of different rotation results for the middle segment show that the thermometer code arrangement corresponding to the same input codeword is different under different cycles. This clearly illustrates the operation process of the perturbation mechanism of the present invention. The operation mode of the high segment is the same.

[0037] like Figure 4 As shown, this invention presents a comparison curve of the output spectrum before and after the perturbation mechanism, with the horizontal axis representing frequency and the vertical axis representing power. The left graph corresponds to the case without random rotation selection, where significant harmonic components appear near the fundamental frequency in the output spectrum, and the measured spurious-free dynamic range is approximately 39.19 dB. The right graph corresponds to the case after random rotation selection, where the originally concentrated harmonic peaks are suppressed, and spurious energy is distributed over a wider frequency band, with the measured spurious-free dynamic range increasing to approximately 62.69 dB. This demonstrates that, while maintaining correct amplitude, this invention can effectively disperse the fixed harmonics caused by current source mismatch through the rotation perturbation mechanism, thereby improving the dynamic characteristics of the output signal.

[0038] The present invention presents a current-rudder type digital-to-analog converter control circuit based on a multi-stage barrel shift random rotation mechanism. By introducing a barrel shifter driven by a linear feedback shift register into the high- and middle-segment thermometer code paths, the arrangement of logic "1"s is changed while ensuring the correct output weight. This disperses the usage sequence of the current source units in time, thereby reducing the spectral concentration effect caused by mismatch error. Combined with the delay alignment and synthesized output of the low-segment, a circuit scheme with simple structure, low hardware cost, and improved dynamic characteristics is achieved.

[0039] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A current-controlled analog-to-digital converter with random rotation selection function, characterized in that: It includes an input register, a segmented decoding module, a delay unit, a random rotation selection module, and a current source array. The random rotation selection module includes a random rotation module and a synthesis latch module. The input register receives a digital signal of the target bit width, latches it, and divides it into high-bit, middle-bit, and low-bit signals. The high-bit and middle-bit signals are first decoded by a segmented decoding module under a preset target clock cycle to generate high-bit and middle-bit thermometer code control signals, respectively. These signals are then updated by a random rotation module through random rotation and shift transformation and sent to the synthesis latch module. Simultaneously, a delay unit performs a delay on the low-bit signal under a preset target clock cycle to form a low-bit control signal, which is sent to the synthesis latch module. The synthesis latch module samples the high-bit, middle-bit, and low-bit thermometer code control signals at the same clock edge and splices them into a complete control signal. This complete control signal drives a current source array to generate a differential current signal for output.

2. The current-controlled digital-to-analog converter with random rotation selection function according to claim 1, characterized in that: The random rotation module includes two sets of linear feedback shift registers corresponding to the high-level thermometer code control signal and the mid-level thermometer code control signal, respectively. For the linear feedback shift register corresponding to the high-level thermometer code control signal, the bits with a preset first bit width in the linear feedback shift register are used as the rotation control signal. The rotation control signal controls the cyclic shift stage of the barrel shift register. The barrel shifter receives the high-level thermometer code control signal and performs random rotation shift transformation and update under the drive of the rotation control signal. The preset first bit width is equal to the bit width of the high-level signal. Regarding the linear feedback shift register corresponding to the median thermometer code control signal, each bit of the preset second bit width in the linear feedback shift register is used as the rotation control signal. The rotation control signal controls the cyclic shift stage of the barrel shift register. The barrel shifter receives the median thermometer code control signal and performs random rotation shift transformation update under the drive of the rotation control signal. The preset second bit width is equal to the bit width of the median signal.

3. A current-controlled digital-to-analog converter with random rotation selection function according to claim 2, characterized in that: Based on the fact that the high-order signal has a bit width of 5 bits and the middle-order signal has a bit width of 3 bits, the random rotation module includes two sets of 32-bit linear feedback shift registers corresponding to the high-order thermometer code control signal and the middle-order thermometer code control signal, respectively. Among them, regarding the linear feedback shift register corresponding to the high-order thermometer code control signal, bits 3, 10, 17, 24, and 31 in the linear feedback shift register are used as rotation control signals to control the cyclic shift stages in the barrel shifter with shift amounts of 1, 2, 4, 8, and 16, respectively. The barrel shifter receives the high-order thermometer code control signal and performs random rotation shift transformation update within a single clock cycle under the drive of the rotation control signal. Regarding the linear feedback shift register corresponding to the median thermometer code control signal, bits 10, 20, and 30 in the linear feedback shift register are used as rotation control signals to control the cyclic shift stages in the barrel shifter with shift amounts of 1, 2, and 4, respectively. The barrel shifter receives the median thermometer code control signal and performs random rotation shift transformation updates within a single clock cycle under the drive of the rotation control signal.

4. A current-controlled digital-to-analog converter with random rotation selection function according to claim 2, characterized in that: While the synthetic latch module outputs the complete spliced ​​control signal, it also outputs the high-level thermometer code control signal and the middle-level thermometer code control signal before the random rotation shift transformation update.

5. A current-controlled digital-to-analog converter with random rotation selection function according to claim 1, characterized in that: The current source array includes a first equal-amplitude current source array, a second equal-amplitude current source array, and a weighted current source array, which correspond to the high, middle, and low bits of the complete control signal, respectively. Under the control of the control signal of the corresponding bit in the complete control signal, each current source array switches the current to the positive output terminal or the reverse output terminal through its own differential switch, and connects to the positive output terminal of each current source array and the reverse output terminal of each current source array to output a differential current signal.

6. A current-controlled digital-to-analog converter with random rotation selection function according to claim 5, characterized in that: Based on a 31-bit high-level thermometer code control signal, a 7-bit mid-level thermometer code control signal, and a 4-bit low-level control signal, the first equal-amplitude current source array includes 31 128×I equal-amplitude current units, the second equal-amplitude current source array includes 7 16×I equal-amplitude current units, and the weighted current source array includes 4 binary weighted current units: 8×I weighted current unit, 4×I weighted current unit, 2×I weighted current unit, and 1×I weighted current unit.

7. A current-controlled digital-to-analog converter with random rotation selection function according to claim 1, characterized in that: It also includes a clock drive circuit, which receives the clock signal CLK and provides clock drive signals to the input register, the random rotation module and the synthetic latch module in the random rotation selection module as the basis for operation.

8. A current-controlled digital-to-analog converter with random rotation selection function according to claim 1, characterized in that: The input register receives a 12-bit binary digital signal, latches it, and divides it into a high-bit signal (5 bits), a middle-bit signal (3 bits), and a low-bit signal (4 bits). The high-bit signal and the middle-bit signal are decoded by the segmented decoding module to generate a 31-bit high-bit thermometer code control signal and a 7-bit middle-bit thermometer code control signal.

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