Sigma-delta modulator based on pulse distribution and capacitance selection

Abstract

The invention discloses a sigma-delta modulator based on pulse distribution and capacitance selection, and belongs to the field of signal processing, and the sigma-delta modulator comprises a pulse distribution unit which controls the time sequence of an input signal through distribution pulses; the signal switch unit is used for controlling the channel state of the input signal; the capacitance selection unit comprises an operational amplifier, at least two switches and at least two capacitors controlled by the switches; and the adaptive unit is used for adaptively adjusting the pulse distribution unit and the capacitance selection unit through the performance of the output signal. Firstly, the time sequence of an input signal is controlled through the pulse distribution unit, the input signal selects the operational amplifier with any capacitance value through the switch, then the output signal is compared through the self-adaption unit, and the capacitance value and the time sequence of the signal which does not meet the requirement are adjusted in a self-adaption mode. According to the structure, the performance and the flexibility of the sigma-delta modulator under different signal conditions are remarkably improved, signal distortion caused by fixed capacitance values is avoided by selecting different capacitors, and the accuracy and the reliability of digital signals are improved.

Description

Technical Field

[0001] The present application relates to the field of signal processing, and in particular, to a sigma-delta modulator based on pulse distribution and capacitor selection. Background Art

[0002] With the development of electronic technology, the requirements for the accuracy and reliability of signal processing are getting higher and higher. In the process of converting analog signals into digital signals, sigma-delta modulators are widely used in analog-to-digital converters due to their high resolution and low noise characteristics. Sigma-delta modulators push quantization noise to the high frequency band through oversampling and noise shaping technology, thereby providing an output signal with a high signal-to-noise ratio in the low frequency band.

[0003] However, the performance of the sigma-delta modulator is limited by its internal components. For example, when the existing sigma-delta modulator processes high-frequency or high-resolution signals, the pulse distribution of the input signal and the capacitor setting of the differential amplifier have an important impact on the overall performance of the modulator, especially the capacitor value selection of the differential amplifier. The traditional fixed capacitor value design cannot adapt to the optimal performance under different signal conditions, so it is necessary to develop a technology that can be dynamically adjusted according to the signal characteristics to improve the accuracy and stability of the modulator. Summary of the invention

[0004] Based on the deficiencies of the prior art and to address the problem that signal modulation cannot meet optimal performance due to the existing fixed capacitance, an embodiment of the present application provides a sigma-delta modulator based on pulse distribution and capacitor selection, including: a pulse distribution unit, specifically a pulse distributor, for controlling the timing of an input signal by distributing pulses; a signal switching unit, for controlling the channel state of an input signal; a capacitor selection unit, the capacitor selection unit including an operational amplifier, at least two switches, and at least two capacitors controlled by the switches; and an adaptive unit, for adaptively adjusting the pulse distribution unit and the capacitor selection unit according to the performance of an output signal.

[0005] Optionally, in the capacitance selection unit, the at least two capacitors are preset to have different capacitance values ​​for adjusting the capacitance of the operational amplifier.

[0006] Optionally, in the capacitance selection unit, the number of the switches is the same as the number of the capacitors.

[0007] Optionally, the pulse distribution unit modulates at least one input signal synchronously or asynchronously by controlling the timing of the input signal.

[0008] Optionally, the adaptive unit adaptively selects other capacitors in the capacitance selection unit according to the performance of the output signal.

[0009] Optionally, the adaptive unit triggers the timing control of other input signals in the pulse distribution unit through the performance of the output signal.

[0010] The beneficial effect of the present application is that, compared with the prior art, the sigma-delta modulator based on pulse distribution and capacitor selection proposed by the present invention can significantly improve the performance and flexibility of the sigma-delta modulator under different signal conditions. By adaptively adjusting the capacitor, signal distortion caused by capacitor mismatch or improper gain setting can be reduced, thereby improving the accuracy and reliability of the modulated digital signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0012] Figure 1 It is a schematic diagram of the structure of a sigma-delta modulator based on pulse distribution and capacitor selection;

[0013] Figure 2 It is a logic diagram for asynchronous timing control of two input signals through a pulse distributor;

[0014] Figure 3 It is a schematic diagram of timing control of conditional triggering of two input signals through a pulse distributor.

[0015] The above drawings include the following reference numerals:

[0016] 1- Pulse divider, 2- Switch, 3- Capacitor, 4- Fully differential operational amplifier, 5- Comparator. DETAILED DESCRIPTION

[0017] In order to enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only embodiments of a part of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work should fall within the scope of protection of the present application.

[0018] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0019] Figure 1 The figure shows a schematic diagram of a sigma-delta modulator structure based on pulse distribution and capacitor selection, including a pulse distribution unit, specifically a pulse distributor 1, for distributing pulses of an input signal to control the timing of the input signal; a signal switch unit, including at least n switches 2, n is a positive integer, n is greater than or equal to 2, and a capacitor is arranged behind each switch, and the capacitance value is specifically C1, C2, C3...C n , used to control the channel state of the input signal; a capacitor selection unit, including a fully differential operational amplifier 4, 6 switches, and 3 capacitors 3 for each positive and negative cycle, and different capacitance values ​​are preset in the 6 capacitors, and the specific capacitance value is C 11 , C 12 , C 13， A fully differential operational amplifier is used to select one or more capacitance values ​​for modulation; an adaptive unit, specifically a comparator 5, compares whether the current signal meets the requirements after the input signal is modulated, and adaptively adjusts the capacitance value and the timing of the input signal for the signal that does not meet the requirements.

[0020] Among them, the number of capacitors in the capacitor selection unit is at least 2, which is not specifically limited in the present application, and the number of switches controlling the capacitors is the same as the number of capacitors and corresponds one to one.

[0021] Among them, when there are at least 4 switches in the signal switching unit, when two input signals enter the sigma-delta modulator, the channel state of the signal can be controlled to allow 2-way signal input by closing the switch, and the pulse distributor controls the timing of the 2-way input signals to be synchronous or asynchronous input, that is, the 2-way input signals can be modulated synchronously or asynchronously through the current sigma-delta modulator.

[0022] The specific working principle is: the input signal distributes pulses to each input signal through a pulse distributor to control the timing of each input signal, determine the input of one signal or multiple signals, and when the input signal enters the fully differential operational amplifier for operational amplification, select the corresponding capacitance value for each signal. Different signals can choose operational amplifiers with the same or different capacitance values. After the signal is operationally amplified, the comparator is used to compare whether the modulated output signal meets the performance requirements of the signal. For signals that do not meet the requirements, other capacitance values ​​are reselected until the modulated output signal meets the requirements.

[0023] The derivation formula of the output signal is formula (1):

[0024] (1)

[0025] Among them, C 11 is the capacitance value selected by the differential amplifier, C1 and C2 are the switch capacitance values ​​of the two input signals, and V out is the output signal, V1 is the first input signal, and V2 is the second input signal.

[0026] According to formula (1), after the output signal is output, the comparator compares the output signal If the current output signal does not meet the signal processing requirements, the adaptive unit adjusts the output signal by reselecting the capacitance value of the fully differential operational amplifier. For example, the capacitance value is C 11 The capacitor is reselected to have a capacitance value of C 12 The capacitor is adjusted until the output signal can meet the signal processing requirements. At this time, the purpose of changing the signal characteristics by adjusting the capacitance value is achieved.

[0027] According to the principle of the above sigma-delta modulator, in one embodiment, Figure 2 The figure shows a logic diagram of asynchronous timing control of two input signals through a pulse distributor. First, the two switches of the signal switch unit are controlled to close, and then the pulse distributor distributes pulses to control the timing of the two input signals. Figure 2 As shown, at this time, the timing of the two input signals is asynchronous modulation, and then a capacitor with any capacitance value is selected for each signal. The capacitance values ​​of the two input signals can be the same or different, that is, the capacitance value selected for one signal is C 11 The capacitance value of the other signal can be selected as C 11 Capacitors with capacitance values ​​of C 12The capacitance value of the capacitor is not specifically limited in this application. The two signals are then operationally amplified. After the signals are modulated, a comparator is used to compare whether the current output signal meets the signal requirements. The capacitance value of the signal that does not meet the requirements is adaptively adjusted until the current signal is output after the signal requirements are met.

[0028] In another embodiment, Figure 3 The figure shows a logic diagram of timing control of conditional triggering of two input signals through a pulse distributor. The sampling signals are one pressure signal and one temperature signal. When the output signal of the pressure signal after modulation is the set threshold, the temperature signal is modulated. First, one switch of the pressure input signal is controlled to be closed, and the timing of the pressure signal is controlled by the pulse distributor to modulate the current signal. A differential amplifier of any capacitance value is selected. After the pressure signal is modulated, the signal is adaptively modulated by the comparator, and the output signal is judged. When the preset threshold is reached, the second switch is controlled to be closed, and the timing of the temperature is modulated by the pulse distributor. A differential amplifier of any capacitance value is selected for the temperature signal. When the output signal does not meet the requirements of accuracy, the capacitance value of the differential amplifier is adaptively selected until the two output signals are output when the accuracy requirements are met.

[0029] In summary, by adaptively adjusting the capacitance value of the differential amplifier and allocating the timing of the input signal, the characteristics of the modulated output signal can be changed for input signals within any range, solving the problem of signal distortion caused by fixed capacitance value and improving the reliability and stability of signal modulation.

[0030] The serial numbers of the above-mentioned embodiments of the present application are for description only and do not represent the advantages or disadvantages of the embodiments.

[0031] In the above embodiments of the present application, 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 relevant description of other embodiments.

[0032] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. Among them, the device embodiments described above are only schematic. For example, the division of the units can be a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of units or modules, which can be electrical or other forms.

[0033] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple units. Some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0034] The above is only a preferred implementation of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A sigma-delta modulator based on pulse distribution and capacitor selection, characterized in that: include: A pulse distribution unit, specifically a pulse distributor, for controlling the timing of an input signal by distributing pulses; A signal switch unit, used to control the channel state of the input signal; a capacitance selection unit, the capacitance selection unit comprising an operational amplifier, at least two switches, and at least two capacitors controlled by the switches; An adaptive unit is used to adaptively adjust the pulse distribution unit and the capacitor selection unit according to the performance of the output signal.

2. A sigma-delta modulator based on pulse distribution and capacitor selection according to claim 1, characterized in that: In the capacitance selection unit, the at least two capacitors are preset to have different capacitance values ​​for adjusting the capacitance of the operational amplifier.

3. A sigma-delta modulator based on pulse distribution and capacitor selection according to claim 1, characterized in that: In the capacitance selection unit, the number of the switches is the same as the number of the capacitors.

4. A sigma-delta modulator based on pulse distribution and capacitor selection according to claim 1, characterized in that: The pulse distribution unit modulates at least one input signal synchronously or asynchronously by controlling the timing of the input signal.

5. A sigma-delta modulator based on pulse distribution and capacitor selection according to claim 1, characterized in that: The adaptive unit adaptively selects other capacitors in the capacitance selection unit according to the performance of the output signal.

6. A sigma-delta modulator based on pulse distribution and capacitor selection according to claim 1, characterized in that: The adaptive unit triggers the timing control of other input signals in the pulse distribution unit through the performance of the output signal.

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