阅读说明：本技术 D类功放的接口电路以及数字输入的d类功放电路 (The interface circuit of D class power amplifier and the D class power amplifier of numeral input ) 是由 魏建磊 丁庆 于 2019-08-02 设计创作，主要内容包括：本发明涉及一种D类功放的接口电路和数字输入的D类功放电路。数模转换模块和重建滤波模块,数模转换模块接收对数字音频信号进行数字采集、转换得到的数字控制信号,将数字控制信号转化为第一电流信号和第二电流信号,第一电流信号和第二电流信号中均包括转换时引入的高频量化噪声,重建滤波模块的第一输入端接收第一电流信号,重建滤波模块的第二输入端接收第二电流信号,通过运算放大器构建的一组正反向输入的低通滤波器分别对第一电流信号和第二电流信号进行低通滤波,滤除第一电流信号和所述第二电流信号中的所述高频量化噪声。本发明在滤除高频量化噪声的同时,降低了电路的体积和成本。(The present invention relates to the D class power amplifiers of a kind of interface circuit of D class power amplifier and numeral input.D/A converter module and re-establishing filter module, D/A converter module, which is received, carries out digital collection to digital audio and video signals, the digital controlled signal being converted to, the first current signal and the second current signal are converted by digital controlled signal, the High-frequency quantization noise introduced when including conversion in the first current signal and the second current signal, the first input end of re-establishing filter module receives the first current signal, second input terminal of re-establishing filter module receives the second current signal, the low-pass filter of the one group of forward and reverse input constructed by operational amplifier carries out low-pass filtering to the first current signal and the second current signal respectively, filter out the High-frequency quantization noise in the first current signal and second current signal.The present invention reduces the volume and cost of circuit while filtering out High-frequency quantization noise.)

1. a kind of interface circuit of D class power amplifier, which is characterized in that the circuit includes:

D/A converter module and re-establishing filter module；

The D/A converter module receives the digital controlled signal for carrying out digital collection to digital audio and video signals, being converted to, will The digital controlled signal is converted into the first current signal and the second current signal；First current signal and second electricity The High-frequency quantization noise introduced when including conversion in stream signal；

The first input end of the re-establishing filter module receives first current signal, and the second of the re-establishing filter module is defeated Enter end and receives second current signal；Low-pass filter by one group of forward and reverse input of operational amplifier building is right respectively First current signal and second current signal carry out low-pass filtering, filter out first current signal and described second The High-frequency quantization noise in current signal.

2. circuit according to claim 1, which is characterized in that one group of forward and reverse input of the operational amplifier building Low-pass filter: positive low-pass filter and reversed low-pass filter；

The forward direction low-pass filter is that the positive input of the operational amplifier inputs；The reversed low-pass filter is institute State the reverse input end input of operational amplifier.

3. circuit according to claim 2, which is characterized in that the forward direction low-pass filter and the reversed low-pass filtering Device is the multiterminal feedback mode filter of negative-feedback.

4. circuit according to any one of claims 2 to 3, which is characterized in that the forward direction low-pass filter and reversed low Bandpass filter is altogether.

5. circuit according to claim 1, which is characterized in that the D/A converter module includes current source array；

Two output ends of the current source array are grounded by first resistor and second resistance；

The remote ground terminal of the first resistor is connect with the first input end, the remote ground terminal of the second resistance and described second defeated Enter end connection.

6. circuit according to claim 5, which is characterized in that it is corresponding that the first input end receives first electric current First voltage, the first voltage include: the first common-mode voltage and the first alternating voltage；It include height in first alternating voltage Frequency quantizing noise；

Second input terminal receives the corresponding second voltage of second electric current, second common-mode voltage and the second alternating current Pressure；It include High-frequency quantization noise in second alternating voltage；

The High-frequency quantization noise in first alternating voltage and second alternating voltage is filtered out by the low-pass filter；

First common-mode voltage and second common-mode voltage input the common-mode feedback of the operational amplifier to the interface The load of circuit carries out common mode matching.

7. a kind of D class power amplifier of numeral input, which is characterized in that including D class function as claimed in any one of claims 1 to 6 Digital interface circuit, D class power amplifier analog module and the digital input module put；

The digital input module acquires digital audio and video signals, and converts digital controlled signal for the digital audio and video signals, And the digital controlled signal is sent to the digital interface circuit；

The digital interface circuit receives the digital controlled signal, carries out High-frequency quantization noise filter to the digital controlled signal The matching of the common mode of wave and D class power amplifier analog module, the analog audio signal after being rebuild, and by the analog audio signal It is sent to D class power amplifier analog module.

8. the D class power amplifier of numeral input according to claim 7, which is characterized in that the digital input module packet Include sequentially connected digital acquisition unit, interpolated value filter unit, number sigma-delta modulation unit, finite impulse response (FIR) Unit and dynamic element matching unit；

The digital acquisition unit carries out the acquisition of the digital audio and video signals；

The dynamic element matching unit exports the digital controlled signal.

Technical field

The present invention relates to power electronics fields, and the interface circuit and number more particularly to a kind of D class power amplifier are defeated The D class power amplifier entered.

Background technique

In conventional crystal amplifier, the transistor in output stage needs to provide the moment and continuously exports electric current.Sound A variety of ways of realization that acoustic system can use include the amplifier of A class, AB class and B class, compared with class-D amplifier, these electricity Lu Zhong, even the highest linear output stage of efficiency, the dissipation of power are very big.Under this condition, class-D amplifier is in many Application aspect has significant advantage, and lesser power dissipation means lower calorific value and circuit board space and cost Saving and portable system battery working time extension.

In open loop D class power amplifier, when digital signal inputs D class power amplifier, it can be introduced largely since digital-to-analogue is converted into High-frequency quantization noise, power supply noise is almost directly coupled to output loudspeaker, therefore the sound quality of loudspeaker output is caused It influences, currently, the bandwidth of incoming audio signal can be identified using processor, to select sample frequency according to bandwidth and cut Frequency is changed, thus filter high-frequency quantizing noise, then this mode realizes complexity, and special processor identifies bandwidth, Increase the cost of chip.

Summary of the invention

Based on this, it is necessary to solving the problems, such as High-frequency quantization noise influence output, provide a kind of interface of D class power amplifier The D class power amplifier of circuit and numeral input.

A kind of interface circuit of D class power amplifier, the circuit include:

D/A converter module and re-establishing filter module；

The D/A converter module receives the digital control letter for carrying out digital collection to digital audio and video signals, being converted to Number, the first current signal and the second current signal are converted by the digital controlled signal；First current signal and described The High-frequency quantization noise introduced when including conversion in the second current signal；

The first input end of the re-establishing filter module receives first current signal, and the of the re-establishing filter module Two input terminals receive second current signal；Pass through the low-pass filter point for one group of forward and reverse input that operational amplifier constructs It is other that low-pass filtering is carried out to first current signal and second current signal, filter out first current signal and described The High-frequency quantization noise in second current signal.

The low-pass filter for one group of forward and reverse input that the operational amplifier constructs in one of the embodiments: just To low-pass filter and reversed low-pass filter；The forward direction low-pass filter is that the positive input of the operational amplifier is defeated Enter；The reversed low-pass filter is that the reverse input end of the operational amplifier inputs.

The positive low-pass filter and the reversed low-pass filter are negative-feedback in one of the embodiments, Multiterminal feed back mode filter.

The positive low-pass filter and reversed low-pass filter be altogether in one of the embodiments,.

The D/A converter module includes current source array in one of the embodiments,；The two of the current source array A output end is grounded by first resistor and second resistance；The remote ground terminal of the first resistor is connect with the first input end, The remote ground terminal of the second resistance is connect with second input terminal.

The first input end receives the corresponding first voltage of first electric current in one of the embodiments, described First voltage includes: the first common-mode voltage and the first alternating voltage；It include High-frequency quantization noise in first alternating voltage；Institute It states the second input terminal and receives the corresponding second voltage of second electric current, second common-mode voltage and the second alternating voltage；Institute Stating includes High-frequency quantization noise in the second alternating voltage；First alternating voltage and described is filtered out by the low-pass filter High-frequency quantization noise in second alternating voltage；First common-mode voltage and second common-mode voltage input the operation and put The common-mode feedback of big device carries out common mode matching to the load of the interface circuit.

A kind of D class power amplifier of numeral input, digital interface circuit, D class power amplifier including any D class power amplifier Analog module and digital input module；

The digital input module acquires digital audio and video signals, and converts digital control letter for the digital audio and video signals Number, and the digital controlled signal is sent to the digital interface circuit；

The digital interface circuit receives the digital controlled signal, carries out High-frequency quantization to the digital controlled signal and makes an uproar Sound filtering and the common mode matching of D class power amplifier analog module, the analog audio signal after being rebuild, and by the analogue audio frequency Signal is sent to D class power amplifier analog module.

The digital input module includes sequentially connected digital acquisition unit, interpolated value in one of the embodiments, Filter unit, number sigma-delta modulation unit, finite impulse response (FIR) unit and dynamic element matching unit；The number Word sampling unit carries out the acquisition of the digital audio and video signals；The dynamic element matching unit exports the digital control letter Number.

The interface circuit of above-mentioned D class power amplifier and the D class power amplifier of numeral input, by being converted into electricity to by digital signal Signal is flowed, low-pass filtering is then carried out to two-way current signal by an operational amplifier, to remove high frequency content therein Change noise, the circuit structure of the embodiment of the present invention is simple, while can be with filter high-frequency quantizing noise.

Detailed description of the invention

Fig. 1 is the structural schematic diagram of the interface circuit of D class power amplifier in one embodiment；

Fig. 2 is the structural schematic diagram of re-establishing filter module in one embodiment；

Fig. 3 is the structural schematic diagram of D/A converter module in one embodiment；

Fig. 4 is the structural schematic diagram of the D class power amplifier of numeral input in one embodiment；

Fig. 5 is the structural schematic diagram of digital input module in one embodiment.

Specific embodiment

Purpose, technical solution and technical effect for a better understanding of the present invention, below in conjunction with drawings and examples Further explaining illustration is carried out to the present invention.State simultaneously, embodiments described below for explaining only the invention, not For limiting the present invention.

In one embodiment, as described in Figure 1, a kind of structural schematic diagram of the interface circuit of D class power amplifier, D class are provided The interface circuit of power amplifier includes: D/A converter module 102 and re-establishing filter module 104.

D/A converter module 102 receives the digital controlled signal for carrying out digital collection to digital audio and video signals, being converted to, The first current signal I1 and the second current signal I2, the first current signal I1 and the second electric current letter are converted by digital controlled signal The High-frequency quantization noise introduced when including conversion in number I2.

The first input end A1 of re-establishing filter module 104 receives the first current signal I1, and the second of re-establishing filter module 104 Input terminal A2 receives the second current signal, and the low-pass filter by one group of forward and reverse input of operational amplifier building is right respectively First current signal and the second current signal carry out low-pass filtering, filter out described in the first current signal and the second current signal High-frequency quantization noise.

Then the interface circuit of above-mentioned D class power amplifier passes through an operation by being converted into current signal to by digital signal Amplifier carries out low-pass filtering to two-way current signal, so that High-frequency quantization noise therein is removed, the electricity of the embodiment of the present invention Line structure is simple, while can be with filter high-frequency quantizing noise.

Specifically, the resistance unit provided in Fig. 1, capacitor cell may each be by multiple element by series, parallel with And go here and there and mix etc. what modes constructed, the necessary device when realizing low-pass filtering, if unnecessary device, then resistance unit or Person's capacitor cell is made of conductive material.

The low-pass filter for one group of forward and reverse input that operational amplifier constructs in one of the embodiments: positive low Bandpass filter and reversed low-pass filter, positive low-pass filter are that the positive input of operational amplifier inputs, reversed low pass Filter is that the reverse input end of the operational amplifier inputs.In the present embodiment, by an operational amplifier, two are constructed Symmetrical low-pass filter, to realize the filtering to two-way current signal.

In one of the embodiments, as shown in Fig. 2, providing a kind of structural schematic diagram of re-establishing filter module, in Fig. 2, Symmetrical low-pass filter is that the multiterminal of negative-feedback feed back mode filter, in each multiterminal feedback mode filter, there is one Negative feedback loop, operational amplifier can be used as a unlimited gain device and carry out feedback loop.

In one of the embodiments, as shown in Fig. 2, it can be seen from the figure that positive low-pass filter and low-pass filtering Device altogether, to realize that positive low-pass filter is consistent with the reference level of low-pass filter.

In one of the embodiments, as shown in figure 3, providing a kind of structural schematic diagram of D/A converter module, digital-to-analogue turns Mold changing block includes current source array, and two output ends of current source array are grounded by first resistor and second resistance, the first electricity The remote ground terminal of resistance is connect with first input end, and the remote ground terminal of second resistance is connect with the second input terminal.In the present embodiment, by electric current The array switching obtained current signal in source is converted to voltage signal by resistance, to be conducive to the waveform weight of re-establishing filter module It builds.

In yet another embodiment, first input end receives the corresponding first voltage of the first electric current, and first voltage includes: the One common-mode voltage and the first alternating voltage, include High-frequency quantization noise in the first alternating voltage, and the second input terminal receives the second electricity Corresponding second voltage, the second common-mode voltage and the second alternating voltage are flowed, includes High-frequency quantization noise in the second alternating voltage, leads to It crosses low-pass filter and filters out High-frequency quantization noise in the first alternating voltage and the second alternating voltage, the first common-mode voltage and second The load of the common-mode feedback interface circuit of common-mode voltage input operational amplifier carries out common mode matching.In the present embodiment, due to It included alternating voltage and common-mode voltage in the voltage signal converted by current signal, alternating voltage is by digital audio and video signals Audio amplitude determine that common-mode voltage is that resistance sizes in current source array determine, therefore, in filtering out alternating voltage High-frequency quantization noise when, it is also necessary in view of the common mode matching problem of common-mode voltage and load.Passing through for the present embodiment is same The common-mode feedback that a operational amplifier is constituted, can solve the common mode matching problem of re-establishing filter module and successive load.

Specifically, operational amplifier is difference engine, difference engine is two inputs, two output, and low-pass filter is using negative anti- The multiterminal of feedback feed back mode filter, so that the common-mode feedback of difference engine can make two output ends and successive load of difference engine Common mode matching.

In addition, in one embodiment, the low-pass filter structure that R1/C2 is constituted in Fig. 2 can also further filter out portion Dividing common-mode noise, the low-pass filter structure that similarly R4/C4 is constituted, R4/C4 is not provided in the example shown, part is piled for R1/C2, Part common-mode noise can also be further filtered out.

In one embodiment, as shown in figure 4, providing a kind of structural schematic diagram of the D class power amplifier of numeral input, packet Include the digital interface circuit 402, D class power amplifier analog module 404 and digital input module 406 of the D class power amplifier in above-described embodiment.

Digital input module 406 acquires digital audio and video signals, and converts digital controlled signal for digital audio and video signals, and Digital controlled signal is sent to digital interface circuit 402；

Digital interface circuit 402 receive digital controlled signal, to digital controlled signal carry out High-frequency quantization noise filtering with And the common mode matching of D class power amplifier analog module 404, the analog audio signal after being rebuild, and analog audio signal is sent To D class power amplifier analog module 404.

The D class power amplifier of the numeral input of the present embodiment can be by digital circuit, therefore can be in a chip In be packaged, without component outside additional piece, so that it may solve to the High-frequency quantization noise filtering problem of input signal with And common mode matching problem.

In one of the embodiments, as shown in figure 5, digital input module include sequentially connected digital acquisition unit, Interpolated value filter unit, number sigma-delta modulation unit, finite impulse response (FIR) unit and dynamic element matching unit, Digital acquisition unit carries out the acquisition of digital audio and video signals, and dynamic element matching unit exports the digital controlled signal.This reality It applies in example, digital input module is made up of said units, and digital input module is allowed to identify the audio letter of various formats Number, and it is converted into the identifiable control signal of identifiable current source array.It, can be in addition, the Parameter adjustable of multiple units Adapt to different scene demands.

Each technical characteristic of embodiment described above can be combined arbitrarily, for simplicity of description, not to above-mentioned reality It applies all possible combination of each technical characteristic in example to be all described, as long as however, the combination of these technical characteristics is not deposited In contradiction, all should be considered as described in this specification.

The embodiments described above only express several embodiments of the present invention, and the description thereof is more specific and detailed, but simultaneously It cannot therefore be construed as limiting the scope of the patent.It should be pointed out that coming for those of ordinary skill in the art It says, without departing from the inventive concept of the premise, various modifications and improvements can be made, these belong to protection of the invention Range.Therefore, the scope of protection of the patent of the invention shall be subject to the appended claims.