[go: up one dir, main page]

CN101350601A - A power amplifier and its signal processing method - Google Patents

A power amplifier and its signal processing method Download PDF

Info

Publication number
CN101350601A
CN101350601A CNA2008101466747A CN200810146674A CN101350601A CN 101350601 A CN101350601 A CN 101350601A CN A2008101466747 A CNA2008101466747 A CN A2008101466747A CN 200810146674 A CN200810146674 A CN 200810146674A CN 101350601 A CN101350601 A CN 101350601A
Authority
CN
China
Prior art keywords
circuit
output
signal
order filter
filter circuit
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CNA2008101466747A
Other languages
Chinese (zh)
Inventor
庞世甫
刘永平
谢旺生
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Huawei Technologies Co Ltd
Original Assignee
Huawei Technologies Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Huawei Technologies Co Ltd filed Critical Huawei Technologies Co Ltd
Priority to CNA2008101466747A priority Critical patent/CN101350601A/en
Publication of CN101350601A publication Critical patent/CN101350601A/en
Priority to PCT/CN2009/072792 priority patent/WO2010025639A1/en
Pending legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F3/00—Amplifiers with only discharge tubes or only semiconductor devices as amplifying elements
    • H03F3/20—Power amplifiers, e.g. Class B amplifiers, Class C amplifiers
    • H03F3/21—Power amplifiers, e.g. Class B amplifiers, Class C amplifiers with semiconductor devices only
    • H03F3/217—Class D power amplifiers; Switching amplifiers

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Amplifiers (AREA)

Abstract

本发明的实施例公开了一种功率放大器及其信号处理方法。该功率放大器包括：二阶滤波电路、调制电路和输出电路，所述二阶滤波电路的输出端与所述调制电路的输入端连接；所述调制电路的输出端与所述输出电路的输入端连接；所述输出电路的输出端分别与所述二阶滤波电路中每阶滤波电路的输入端连接。通过使用本发明的实施例，采用双反馈二阶滤波电路，将信号通过二阶滤波电路进行消噪，然后信号通过调制电路进行调制后经由输出电路输出，可以利用双反馈二阶滤波电路有效地减少调制电路和输出电路产生的谐波失真和噪声，提高了功率放大器的性能，降低了功率放大器的成本。

The embodiment of the invention discloses a power amplifier and a signal processing method thereof. The power amplifier includes: a second-order filter circuit, a modulation circuit and an output circuit, the output end of the second-order filter circuit is connected to the input end of the modulation circuit; the output end of the modulation circuit is connected to the input end of the output circuit connected; the output terminals of the output circuit are respectively connected to the input terminals of each filter circuit in the second-order filter circuit. By using the embodiment of the present invention, a double-feedback second-order filter circuit is adopted, the signal is denoised through the second-order filter circuit, and then the signal is modulated by the modulation circuit and then output through the output circuit, and the double-feedback second-order filter circuit can be used effectively The harmonic distortion and noise generated by the modulation circuit and the output circuit are reduced, the performance of the power amplifier is improved, and the cost of the power amplifier is reduced.

Description

A kind of power amplifier and signal processing method thereof
Technical field
The present invention relates to communication technical field, relate in particular to a kind of power amplifier and signal processing method thereof.
Background technology
Along with the increased popularity of portable consumer electronic product, also more and more higher at present to the requirement of battery working time.Little with efficient height, distortion is that the D class A amplifier A of characteristics begins to be widely used in the middle of these products.For the low-power audio product,, use the D class A amplifier A can prolong the useful life of battery as mobile phone, MP3, MP4 etc.; For the high-power audio product, as multimedia loudspeaker box, power amplifier etc., use the D class A amplifier A can save fin and the transformer that uses small dimension, in energy-conserving and environment-protective, reduce the overall cost of product.Different with traditional class ab ammplifier is, the D class A amplifier A utilize voltage ratio, technology such as pulse-width modulation amplifies audio signal, so the D class A amplifier A is also referred to as digital power amplifier.
Modern D class A amplifier A uses multiple modulator topological structure, and the most basic topology has made up PWM (Pulse Width Modulation, pulse width modulation) and triangular wave (or sawtooth waveforms) oscillator.Fig. 1 is based on the semibridge system D class A amplifier A simplified block diagram of PWM in the prior art.It comprises a pulse-width modulator PMW, two output mos FET (Metal Oxide Semiconductor FieldEffect Transistor, mos field effect transistor) and an outside low pass filter (L who is used to the audio signal recovering to be exaggerated FAnd C F).Wherein, p raceway groove and n channel mosfet alternately are connected to VDD and ground as the conduct current switch with its output node.Because output transistor switches output between VDD or ground, so the final output of D class A amplifier A is a high frequency square wave.Switching frequency (the f of most of D class A amplifier As SW) usually between 250kHz to 1.5MHz.Audio input signal carries out pulse-width modulation to the output square wave.The triangular wave (or sawtooth waveforms) that audio input signal and internal oscillator produce compares, and can obtain pwm signal.This modulation system is commonly referred to as the nature sampling, and wherein triangular wave oscillator is as sampling clock.The duty ratio of square wave is directly proportional with incoming signal level.When not having input signal, the duty ratio of output waveform is 50%.
In order from the PWM waveform, to extract the audio signal after the amplification, need the output of amplifier is connected to a low pass filter.LC low pass filter among Fig. 1 is as passive integrator, and its output equals the mean value of square wave.In addition, low pass filter can prevent dissipation HF switch energy on resistive load.
The inventor finds that there is following problem at least in prior art in realizing process of the present invention:
Need outside LC filter in the realization of this power amplifier.This has not only increased scheme total cost and circuit board space, also may be because of the non-linear additional distortion of introducing of filter element.
Summary of the invention
Embodiments of the invention provide a kind of power amplifier and signal processing method thereof, are used to reduce the cost of power amplifier, improve the performance of power amplifier.
Embodiments of the invention provide a kind of power amplifier, comprising: second-order filter circuit, modulation circuit and output circuit, and the output of described second-order filter circuit is connected with the input of described modulation circuit; The output of described modulation circuit is connected with the input of described output circuit; The output of described output circuit is connected with the input of every rank filter circuit in the described second-order filter circuit respectively.
Embodiments of the invention also provide the signal processing method in a kind of power amplifier, are applied to comprise in the power amplifier of second-order filter circuit, modulation circuit and output circuit, comprising:
Described second-order filter circuit sends to described modulation circuit with output signal;
Described output circuit is modulated and outputed to described modulation circuit to described signal;
The signal of described output circuit after according to described modulation exported, and output signal fed back to the input of every rank filter circuit in the described second-order filter circuit respectively.
Compared with prior art, embodiments of the invention have the following advantages:
The embodiment of the application of the invention, adopt two feedback second-order filter circuits, signal is carried out de-noising by second-order filter circuit, signal is modulated by modulation circuit after exported by output circuit then, can utilize two feedback second-order filter circuits to reduce the harmonic distortion and the noise of modulation circuit and output circuit generation effectively, improve the performance of power amplifier, reduced the cost of power amplifier.
Description of drawings
Fig. 1 is based on the schematic diagram of the semibridge system D class A amplifier A of PWM in the prior art;
Fig. 2 is the schematic diagram of the power amplifier that provides in the embodiments of the invention;
Fig. 3 is the AC characteristic schematic diagram of embodiments of the invention intermediate power amplifier;
Fig. 4 is the PWM modulation output schematic diagram of embodiments of the invention intermediate power amplifier;
Fig. 5 is that the circuit simulation result of embodiments of the invention intermediate power amplifier exports the VOUT schematic diagram;
Fig. 6 A and 6B are the output DFT test result schematic diagrames of embodiments of the invention intermediate power amplifier;
Fig. 7 is the signal processing method flow chart in the embodiments of the invention intermediate power amplifier.
Embodiment
Embodiments of the invention provide a kind of power amplifier, as shown in Figure 2, are made up of second-order filter circuit 10, modulation circuit 20 and output circuit 30.The output of second-order filter circuit 10 is connected with the input of modulation circuit 20; The output of modulation circuit 20 is connected with the input of output circuit 30; The output of output circuit 30 is connected with the input of every rank filter circuit in the second-order filter circuit 10 respectively.This power amplifier can be the D power-like amplifier.
Wherein second-order filter circuit 10 outputs to signal modulation circuit 20; Modulation circuit 20 is generally the PWM modulation circuit, relatively produces output signal by input signal and triangular wave or sawtooth waveforms (being produced by RAMP), and output signal can be pwm signal.The pwm signal that modulation circuit 20 produces outputs to the driving stage of output circuit 30, and pwm signal produces output by output circuit 30.The output signal of output circuit 30 feeds back to the input of every rank filter circuit in the second-order filter circuit 10 simultaneously, forms a closed-loop system, makes power amplifier that good robustness be arranged.
In addition, second-order filter circuit 10 is made up of first integrator 11 and second integral device 12, the anti-phase respectively difference input that is connected to second integral device 12 of the difference output of first integrator 11.The output signal of output circuit 30 feeds back to the first integrator 11 in the second-order filter circuit 10 and the input of second integral device 12 respectively.Stable for the guaranteed output amplifier in addition, the slope that the SR (Slew Rate, switching rate) that each integrator in the second-order filter circuit 10 can be set produces less than triangular wave or sawtooth waveforms.
Because the driving stage of modulation circuit 20 and output circuit 30 is easy to generate harmonic distortion and noise, can carry out noise shaping to the noise of this part by two second-order filter circuits 10 that feed back to, realize high performance circuit.
As shown in Figure 2, first integrator 11 and second integral device 12 are formed a second-order low-pass filter, and transfer function is:
Y ( s ) = R 2 R 1 * 1 1 + s R 2 R 3 C 1 / R 4 + s 2 R 2 R 3 C 1 C 2 / K · X ( s ) + s 2 R 2 R 3 C 1 C 2 1 + s R 2 R 3 C 1 / R 4 + s 2 R 2 R 3 C 1 C 2 / K · E ( s )
Wherein, K is the gain from the PWM modulator.When K=1, following formula becomes:
Y ( s ) = R 2 R 1 * 1 1 + s R 2 R 3 C 1 / R 4 + s 2 R 2 R 3 C 1 C 2 · X ( s ) + s 2 R 2 R 3 C 1 C 2 1 + s R 2 R 3 C 1 / R 4 + s 2 R 2 R 3 C 1 C 2 · E ( s )
By changing R 1Value, can change the gain and the transfer function of power amplifier, realize that volume regulates.
Carry out behavioral scaling emulation for above-mentioned power amplifier shown in Figure 2, condition is the V of input signal In=1.5V, f=1kHz, simulation result such as Fig. 3, Fig. 4 and shown in Figure 5.Wherein, Fig. 3 is AC (Alternating Current, the alternating current) characteristic of power amplifier, and as shown in Figure 3, the resistance and the electric capacity that change in the power amplifier are little to the overall performance influence, show this power amplifier stalwartness.Fig. 4 is the PWM modulation output of adopting the embodiment of the invention, and Fig. 5 is that the circuit simulation result of power amplifier exports VOUT under the condition of above-mentioned input signal.Shown in Fig. 6 A and 6B, adopting output DFT (Distortion-Free Technology, it the is true to disappear) test result of the embodiment of the invention is 120dB, and this D power-like amplifier that shows that the embodiment of the invention discloses is simple in structure, performance is higher.
Embodiments of the invention also provide the signal processing method in a kind of power amplifier, are applied to comprise in the power amplifier of second-order filter circuit, modulation circuit and output circuit, as shown in Figure 7, comprising:
Step s701, second-order filter circuit send to described modulation circuit with output signal;
Described output circuit is modulated and outputed to step s702, modulation circuit to described signal;
Step s703, the output circuit signal after according to described modulation is exported, and output signal is fed back to the input of every rank filter circuit in the described second-order filter circuit respectively.
Wherein, when described second-order filter circuit specifically comprises first integrator and second integral device, the anti-phase respectively difference input that is connected to described second integral device of the difference of described first integrator output;
The step that the power output of described output circuit feeds back to the input of every grade of integrator circuit in the described second-order filter circuit specifically comprises: the power output of described output circuit feeds back to the input of described first integrator and described second integral device.
Wherein, described modulation circuit is the pulse width modulation (PWM) modulation circuit, and the signal that described PWM modulation circuit produces is a pwm signal.The step that described PWM modulation circuit produces pwm signal specifically comprises: input signal and the triangular wave or the sawtooth signal of the more described second-order filter circuit of described PWM modulation circuit produce pwm signal.
Wherein, the slope that the switching rate of each integrator produces less than described triangular wave or sawtooth waveforms in the described second-order filter circuit.
Wherein, this power amplifier can be the D power-like amplifier.
Embodiments of the invention adopt two feedback second-order filter circuits, signal is carried out de-noising by second-order filter circuit, signal is modulated by modulation circuit after exported by output circuit then, can utilize two feedback second-order filter circuits to reduce the harmonic distortion and the noise of modulation circuit and output circuit generation effectively, improve the performance of power amplifier, reduced the cost of power amplifier.In addition, grid utilize the inductance of external loudspeaker coil self and the natural filter action of loud speaker and people's ear to recover audio frequency component from square wave output after driving output-stage circuit output again, have saved output filter.Embodiments of the invention adopt two reponse systems and second-order filter circuit can solve the bigger problem of harmonic distortion of prior art, less demanding to back level comparator and design of drive circuit, realize than being easier to, and circuit structure is simple, can obtain low distortion, low-power consumption, chip area is little and good stability, be greatly improved on the performance, significantly reduced the power amplifier cost, thereby a scheme littler, more cheap, that efficient is higher is provided.
More than disclosed only be several specific embodiment of the present invention, still, the present invention is not limited thereto, any those skilled in the art can think variation all should fall into protection scope of the present invention.

Claims (10)

1、一种功率放大器，其特征在于，包括：二阶滤波电路、调制电路和输出电路，所述二阶滤波电路的输出端与所述调制电路的输入端连接；所述调制电路的输出端与所述输出电路的输入端连接；所述输出电路的输出端分别与所述二阶滤波电路中每阶滤波电路的输入端连接。1, a kind of power amplifier is characterized in that, comprises: second-order filter circuit, modulation circuit and output circuit, the output end of described second-order filter circuit is connected with the input end of described modulation circuit; The output end of described modulation circuit connected to the input end of the output circuit; the output end of the output circuit is respectively connected to the input end of each order filter circuit in the second order filter circuit. 2、如权利要求1所述功率放大器，其特征在于，所述二阶滤波电路具体包括：第一积分器以及第二积分器，所述第一积分器的差分输出分别反相连接到所述第二积分器的差分输入，且所述输出电路的输出端分别与所述第一积分器的输入端、以及所述第二积分器的输入端连接。2. The power amplifier according to claim 1, wherein the second-order filter circuit specifically comprises: a first integrator and a second integrator, and the differential outputs of the first integrator are connected to the The differential input of the second integrator, and the output terminals of the output circuit are respectively connected to the input terminals of the first integrator and the input terminals of the second integrator. 3、如权利要求1或2所述功率放大器，其特征在于，所述调制电路为脉冲宽度调制PWM调制电路，所述PWM调制电路产生的信号为PWM信号。3. The power amplifier according to claim 1 or 2, wherein the modulation circuit is a pulse width modulation (PWM) modulation circuit, and the signal generated by the PWM modulation circuit is a PWM signal. 4、如权利要求3所述功率放大器，其特征在于，所述PWM调制电路比较所述二阶滤波电路的输入信号与三角波或者锯齿波信号，产生PWM信号。4. The power amplifier according to claim 3, wherein the PWM modulation circuit compares the input signal of the second-order filter circuit with the triangular wave or sawtooth wave signal to generate a PWM signal. 5、如权利要求2或4所述功率放大器，其特征在于，所述二阶滤波电路中各积分器的转换速率小于所述三角波或锯齿波信号产生的斜率。5. The power amplifier according to claim 2 or 4, wherein the slew rate of each integrator in the second-order filter circuit is smaller than the slope generated by the triangular wave or sawtooth wave signal. 6、一种功率放大器中的信号处理方法，其特征在于，应用于包括二阶滤波电路、调制电路和输出电路的功率放大器中，包括：6. A signal processing method in a power amplifier, characterized in that it is applied in a power amplifier comprising a second-order filter circuit, a modulation circuit and an output circuit, including: 所述二阶滤波电路将输出信号发送到所述调制电路；The second-order filter circuit sends an output signal to the modulation circuit; 所述调制电路对所述信号进行调制并输出到所述输出电路；The modulation circuit modulates the signal and outputs it to the output circuit; 所述输出电路根据所述调制后的信号进行输出，并将输出信号分别反馈到所述二阶滤波电路中每阶滤波电路的输入端。The output circuit outputs according to the modulated signal, and feeds back the output signal to the input end of each filter circuit in the second-order filter circuit. 7、如权利要求6所述的方法，其特征在于，所述二阶滤波电路具体包括第一积分器以及第二积分器时，所述第一积分器的差分输出分别反相连接到所述第二积分器的差分输入；7. The method according to claim 6, wherein when the second-order filter circuit specifically includes a first integrator and a second integrator, the differential outputs of the first integrator are connected to the differential input of the second integrator; 所述将输出信号分别反馈到所述二阶滤波电路中每阶滤波电路的输入端的步骤具体包括：所述输出电路将输出信号分别反馈到所述第一积分器以及所述第二积分器的输入端。The step of feeding back the output signals to the input terminals of each filter circuit in the second-order filter circuit specifically includes: the output circuit feeds back the output signals to the first integrator and the second integrator respectively. input. 8、如权利要求6或7所述的方法，其特征在于，所述调制电路为脉冲宽度调制PWM调制电路，所述PWM调制电路产生的信号为PWM信号。8. The method according to claim 6 or 7, wherein the modulation circuit is a pulse width modulation (PWM) modulation circuit, and the signal generated by the PWM modulation circuit is a PWM signal. 9、如权利要求8所述的方法，其特征在于，所述PWM调制电路产生PWM信号的步骤具体包括：9. The method according to claim 8, wherein the step of generating the PWM signal by the PWM modulation circuit specifically comprises: 所述PWM调制电路比较所述二阶滤波电路的输入信号与三角波或者锯齿波信号，产生PWM信号。The PWM modulation circuit compares the input signal of the second-order filter circuit with the triangular wave or sawtooth wave signal to generate a PWM signal. 10、如权利要求7或9所述的方法，其特征在于，所述二阶滤波电路中各积分器的转换速率小于所述三角波或锯齿波信号产生的斜率。10. The method according to claim 7 or 9, characterized in that the slew rate of each integrator in the second-order filter circuit is smaller than the slope generated by the triangular wave or sawtooth wave signal.
CNA2008101466747A 2008-09-04 2008-09-04 A power amplifier and its signal processing method Pending CN101350601A (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
CNA2008101466747A CN101350601A (en) 2008-09-04 2008-09-04 A power amplifier and its signal processing method
PCT/CN2009/072792 WO2010025639A1 (en) 2008-09-04 2009-07-16 Power amplifier and signal processing method thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CNA2008101466747A CN101350601A (en) 2008-09-04 2008-09-04 A power amplifier and its signal processing method

Publications (1)

Publication Number Publication Date
CN101350601A true CN101350601A (en) 2009-01-21

Family

ID=40269233

Family Applications (1)

Application Number Title Priority Date Filing Date
CNA2008101466747A Pending CN101350601A (en) 2008-09-04 2008-09-04 A power amplifier and its signal processing method

Country Status (2)

Country Link
CN (1) CN101350601A (en)
WO (1) WO2010025639A1 (en)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2010025639A1 (en) * 2008-09-04 2010-03-11 华为技术有限公司 Power amplifier and signal processing method thereof
CN101841308A (en) * 2010-05-24 2010-09-22 无锡汉咏微电子有限公司 Structure of high performance operational amplifier
CN103701421A (en) * 2013-11-12 2014-04-02 青岛歌尔声学科技有限公司 Volume regulating device, volume regulating method and electronic equipment
CN105071777A (en) * 2015-08-10 2015-11-18 来安县新元机电设备设计有限公司 Signal amplifying circuit and device
CN106231496A (en) * 2016-09-08 2016-12-14 深圳市冠旭电子股份有限公司 A kind of based on difference output control circuit and audio amplifier
CN108123691A (en) * 2011-09-08 2018-06-05 伯斯有限公司 Universal audio power amplifier
CN114793313A (en) * 2022-01-14 2022-07-26 电子科技大学 Class D audio power amplifier chip with PSRR reinforcing

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110995192B (en) * 2019-11-16 2023-08-25 东风电驱动系统有限公司 PWM signal processing method and system

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7332962B2 (en) * 2005-12-27 2008-02-19 Amazion Electronics, Inc. Filterless class D power amplifier
CN100586008C (en) * 2007-05-09 2010-01-27 埃派克森微电子有限公司 Switching Amplifier and Its Modulation Method
CN101350601A (en) * 2008-09-04 2009-01-21 华为技术有限公司 A power amplifier and its signal processing method

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2010025639A1 (en) * 2008-09-04 2010-03-11 华为技术有限公司 Power amplifier and signal processing method thereof
CN101841308A (en) * 2010-05-24 2010-09-22 无锡汉咏微电子有限公司 Structure of high performance operational amplifier
CN108123691A (en) * 2011-09-08 2018-06-05 伯斯有限公司 Universal audio power amplifier
CN103701421A (en) * 2013-11-12 2014-04-02 青岛歌尔声学科技有限公司 Volume regulating device, volume regulating method and electronic equipment
CN103701421B (en) * 2013-11-12 2017-01-18 歌尔科技有限公司 Volume regulating device, volume regulating method and electronic equipment
CN105071777A (en) * 2015-08-10 2015-11-18 来安县新元机电设备设计有限公司 Signal amplifying circuit and device
CN105071777B (en) * 2015-08-10 2017-12-15 来安县新元机电设备设计有限公司 A kind of signal amplification circuit and device
CN106231496A (en) * 2016-09-08 2016-12-14 深圳市冠旭电子股份有限公司 A kind of based on difference output control circuit and audio amplifier
CN114793313A (en) * 2022-01-14 2022-07-26 电子科技大学 Class D audio power amplifier chip with PSRR reinforcing

Also Published As

Publication number Publication date
WO2010025639A1 (en) 2010-03-11

Similar Documents

Publication Publication Date Title
CN100527605C (en) Amplifier and radio frequency power amplifier using the same
CN101350601A (en) A power amplifier and its signal processing method
JP3899074B2 (en) Digital PWM input class D acoustic amplifier with PWM negative feedback
US7750731B2 (en) PWM loop filter with minimum aliasing error
CN102916656B (en) Amplifier circuit and modulation signal generating circuit
CN101316114B (en) Spread-spectrum modulation circuit, variable frequency triangular-wave generator and signal processing method
CN100488034C (en) CMOS self-adaptive biasing circuit
JP4535819B2 (en) Drive circuit and portable device including the drive circuit
US11296685B2 (en) PWM modulator having quantizer calibratable for multi-non-ideal gain-affecting characteristics
TWI473419B (en) Frequency doubler
Yeh et al. An electromagnetic interference (EMI) reduced high-efficiency switching power amplifier
CN101557202A (en) High power D-type power amplifier
CN202586876U (en) Difference frequency elimination circuit, pulse width modulation signal generation circuit and amplifier circuit
Yang et al. A low-THD class-D audio amplifier with dual-level dual-phase carrier pulsewidth modulation
CN209184560U (en) A kind of reference voltage generating circuit and Switching Power Supply
CN201550079U (en) A Linear Audio Amplifier with Adaptive and Continuously Variable Power Supply Voltage
CN101453196B (en) amplifier circuit
CN110138343A (en) A kind of power supply for radio-frequency power amplifier based on feedback
CN101383592B (en) Power amplifier and method for reducing common mode noise thereof
US8841950B2 (en) Pulse width modulation for switching amplifier
CN111464141A (en) Digital audio power amplifier and electronic equipment
CN101820254A (en) D-class power amplifier with novel PWM (Pulse-Width Modulation) circuit
US9065398B2 (en) Amplifying circuit capable of suppressing spikes of an audio signal
CN101989836B (en) High Efficiency Audio Amplifier and Related Methods
CN101741324B (en) Integrated sum difference class D power amplifier and its method

Legal Events

Date Code Title Description
C06 Publication
PB01 Publication
C10 Entry into substantive examination
SE01 Entry into force of request for substantive examination
C12 Rejection of a patent application after its publication
RJ01 Rejection of invention patent application after publication

Open date: 20090121