CN201594809U - Closed-loop D type audio amplifier system and audio amplifier - Google Patents
Closed-loop D type audio amplifier system and audio amplifier Download PDFInfo
- Publication number
- CN201594809U CN201594809U CN2009201360009U CN200920136000U CN201594809U CN 201594809 U CN201594809 U CN 201594809U CN 2009201360009 U CN2009201360009 U CN 2009201360009U CN 200920136000 U CN200920136000 U CN 200920136000U CN 201594809 U CN201594809 U CN 201594809U
- Authority
- CN
- China
- Prior art keywords
- operational amplifier
- circuit
- preamplifier
- amplifier
- comparator
- 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.)
- Expired - Fee Related
Links
Images
Landscapes
- Amplifiers (AREA)
Abstract
The utility model is applicable to the field of audio amplifiers and provides a closed-loop D type audio amplifier structure, which comprises a preamplifier circuit to appropriately adjust input signals, an integrating circuit electrically connected with the preamplifier circuit, a comparator electrically connected with the integrating circuit and comparing output signals of the integrating circuit with pulse width modulation carrier waves, a drive circuit for adjusting PWM signals and driving a post-stage circuit, an H-bridge circuit as a power output stage, and a feedback loop for feedback output of the H-bridge circuit to an operational amplifier input end of an preamplifier. The modified closed-loop system structure brings finer amplification performance and has better performance in eliminating system noise, strengthening common mold rejection, reducing offset voltage and the like.
Description
Technical field
The utility model belongs to the audio frequency power amplifier field, relates in particular to a kind of D class audio frequency power amplification system.
Background technology
D class audio frequency power amplifier is a kind of production burst sequence and drives the amplifier of load by pulse train that the pulse duration of pulse train is modulated according to input signal.The power device of D class audio frequency power amplifier always works on off state, and its efficient can reach 100% in theory.This high efficiency not only means energy-conservation, and high efficiency representing and lack heat, for input to heat radiation is removed or reduced to a lot of products from.
D class audio frequency power amplification system generally has open loop structure and closed-loop structure, and open cycle system is directly controlled output signal by input signal, and is simple in structure, be easy to realize, but open cycle system is powerless to intrasystem disturbance, is difficult to realize high control precision.Common open cycle system structure as shown in Figure 1, input signal after the preamplifier adjustment and pulse width modulation carrier relatively obtain PWM ripple output, drive the H-bridge circuit through overdrive circuit again, promote loud speaker by low pass filter reduction waveform at last and sound.This open cycle system is simple in structure, but limited in one's ability to the inhibition of power supply and system noise, and in order to improve systematic function, we have introduced the closed-loop structure of D class audio frequency power amplifier.
Traditional closed-loop D-class audio frequency power amplifier system, as shown in Figure 2, its closed loop feedback is that the output signal of power output stage is passed through feedback resistance R7, R8 feeds back to the input of integrator U2, the difference of input signal and integrated signal is carried out integration through integrator U2, and comparator and triangular wave that integral output signal is input to the back again compare formation PWM waveform.Though this D class audio frequency power amplification system can the inhibition ability certain to having of power supply and system noise, improved the performance of system greatly, but this closed-loop system is not owing to be included in preamplifier within the closed-loop system, thereby to the antijamming capability of system with suppress the ability of noise, still not ideal enough.
The utility model provides a kind of novel D class audio frequency power amplifier closed-loop system, can effectively improve the weak point of traditional D class audio frequency power amplification system, and have its particular performances advantage.
The utility model content
The purpose of this utility model is to provide a kind of D class audio frequency power amplifier closed-loop system, is intended to solve open cycle system power supply and system noise are suppressed problem limited in one's ability.
The utility model is achieved in that a kind of closed-loop D-class audio frequency power amplifier system, and described system comprises:
The preamplifier that input signal is adjusted;
Integrating circuit is electrically connected with described preamplifier;
Comparator is electrically connected with described integrating circuit, and signal and pulse width modulation carrier that described integrating circuit is exported compare;
Drive circuit is used to adjust pwm signal, drives late-class circuit;
The H-bridge circuit is as the system power output stage; And
Feedback loop feeds back to the output of H-bridge circuit the input of preamplifier amplifier.
The utility model has also proposed a kind of audio frequency power amplifier, comprises a closed-loop D-class audio frequency power amplifier system, and this system comprises:
The preamplifier that input signal is adjusted;
Integrating circuit is electrically connected with described preamplifier;
Comparator is electrically connected with described integrating circuit, and signal and pulse width modulation carrier that described integrating circuit is exported compare;
Drive circuit is used to adjust pwm signal, drives late-class circuit;
The H-bridge circuit is as the system power output stage; And
Feedback loop feeds back to the output of H-bridge circuit the input of preamplifier amplifier.
The utility model increases integral element and constitutes negative feedback closed loop by the divided ring system, power supply noise in the closed loop and other system noise are constituted high-pass filtering, again in conjunction with the outer low pass filter 16 of closed loop, by suitable design parameter can the filtering overwhelming majority power supply and system noise, strengthened inhibition ability, and improved control precision power supply and system noise.
Description of drawings
Fig. 1 is the general circuit structure diagram of open loop D class audio frequency power amplification system;
Fig. 2 is traditional closed-loop D-class audio frequency power amplifier circuit system structure chart;
Fig. 3 is the closed-loop D-class audio frequency power amplifier system construction drawing that the utility model provides;
Fig. 4 is the structure chart of the comparator in the closed-loop D-class audio frequency power amplifier system that provides of the utility model;
Embodiment
In order to make the purpose of this utility model, technical scheme and advantage clearer,, the utility model is further elaborated below in conjunction with drawings and Examples.Should be appreciated that specific embodiment described herein only in order to explanation the utility model, and be not used in qualification the utility model.
The system configuration of the utility model by improving strengthened the inhibition ability to power supply and system noise, and improved control precision.
The structure of the closed-loop D-class audio frequency power amplifier system that the utility model provides for convenience of explanation, only shows the part relevant with the utility model as shown in Figure 3.
Closed-loop D-class audio frequency power amplifier system comprises preamplifier 11, integrating circuit 12, comparator 13, drive circuit 14, H-bridge circuit 15, low pass filter 16, feedback circuit 17; Wherein, 11 pairs of input signals of preamplifier are adjusted; Integrating circuit 12 is electrically connected with preamplifier 11; Comparator 13 is electrically connected with integrating circuit 12, and signal and pulse width modulation carrier that integrating circuit is exported compare; Drive circuit 14 is electrically connected with comparator 13; H-bridge circuit 15 is electrically connected with drive circuit 14; Feedback circuit 17 is connected to the output of H-bridge circuit 15 and the input of preamplifier amplifier, the output signal of H-bridge circuit 15 is fed back to the amplifier of preamplifier.
In the utility model, preamplifier 11 comprises: operational amplifier U1, U2, resistance R 3, R4, R5 and R6, capacitor C 1 and C2; The reversed-phase output of operational amplifier U1 is connected to the in-phase input end of operational amplifier U1 by resistance R 3; The in-phase output end of operational amplifier U1 is connected to the inverting input of operational amplifier U1 by resistance R 4.The reversed-phase output of operational amplifier U2 is connected to the in-phase input end of operational amplifier U2 by resistance R 5 and capacitor C 1; The in-phase output end of operational amplifier U2 is connected to the inverting input of operational amplifier U2 by resistance R 6 and capacitor C 2.As an embodiment of the present utility model, preamplifier 11 also comprises resistance R 1 and R2; Resistance R 1 is connected to the in-phase input end of operational amplifier U1 and U2; Resistance R 2 is connected to the inverting input of operational amplifier U1 and U2.
In the utility model, integrating circuit 12 comprises: operational amplifier U3, capacitor C 3 and C4; The reversed-phase output of operational amplifier U3 is connected to the in-phase input end of operational amplifier U3 by capacitor C 3; The in-phase output end of operational amplifier U3 is connected to the inverting input of operational amplifier U3 by capacitor C 4.As an embodiment of the present utility model, integrating circuit 12 further comprises: resistance R 7, R8, R9 and R10; Wherein, resistance R 7 and R9 are connected to the reversed-phase output of operational amplifier U1, U2 and the in-phase input end of operational amplifier U3; Resistance R 8 and R10 are connected to the in-phase output end of operational amplifier U1, U2 and the inverting input of operational amplifier U3.
In the utility model, the structure of comparator 13 comprises as shown in Figure 4: comparator U4 and U5, and the in-phase input end a of comparator U4 is connected with the reversed-phase output of operational amplifier U3; The in-phase input end of comparator U5 is connected with the in-phase output end of operational amplifier U3; The inverting input of the inverting input of comparator U4 and comparator U5 all is connected with external pulse width modulation carrier.
In the utility model, feedback circuit 17 comprises: resistance R 11, R12, R13, R14 and capacitor C 5, C6.Resistance R 11, R12 and capacitor C 5 are exported the in-phase input end that feeds back to the preamplifier amplifier with a road of H-bridge circuit, and resistance R 13, R14 and capacitor C 6 feed back to another road output of H-bridge circuit the inverting input of preamplifier amplifier.
As an embodiment of the present utility model, this closed-loop D-class audio frequency power amplifier system also further comprises drive circuit 14, H-bridge circuit 15 and low pass filter 16.Wherein, drive circuit 14 is used for increasing driving force, drives the work of H-bridge circuit; H-bridge circuit 15 is as the power output stage of time closed-loop D-class audio frequency power amplifier system; Low pass filter 16 is used for reducing audio signal, drives the load loud speaker.
Closed-loop system structure of the present utility model directly feeds back to the input of the preamplifier that is made of double operational with the output signal of power output stage by feedback circuit 17, has formed a big negative feedback closed loop system configuration.Like this, just preamplifier has been also contained within the closed-loop system, the input that feedback signal is directly fed back to preamplifier just can effectively reduce the imbalance and the error that are produced by preamplifier, and traditional D class audio frequency power amplifier closed-loop system does not reach this effect.
In addition, feedback signal is directly fed back to the input of preamplifier, just can improve the input impedance of closed-loop system, thereby further reduce distortion and error.
The novel preamplifier of this use adopts two operational amplifiers double operational that constitutes in parallel, the double operational preamplifier can effectively reduce the noise by the preamplifier introduction, and increased the output current of preamplifier, can effectively reduce the distortion of input audio signal, improve the THD+N (total harmonic distortion) and the SNR (signal to noise ratio) of output signal.
Closed-loop system structure of the present utility model has strengthened the inhibition ability to power supply and system noise, and has improved control precision.
The above only is preferred embodiment of the present utility model; not in order to restriction the utility model; all any modifications of within spirit of the present utility model and principle, being done, be equal to and replace and improvement etc., all should be included within the protection range of the present utility model.
Claims (7)
1. closed-loop D-class audio frequency power amplifier system is characterized in that described system comprises:
The preamplifier that input signal is adjusted;
Integrating circuit is electrically connected with described preamplifier;
Comparator is electrically connected with described integrating circuit, and signal and pulse width modulation carrier that described integrating circuit is exported compare;
Drive circuit is used to adjust pwm signal, drives late-class circuit;
The H-bridge circuit is as the system power output stage; And
Feedback loop feeds back to the output of H-bridge circuit the input of preamplifier amplifier.
2. audio frequency power amplifier as claimed in claim 1 system is characterized in that described system also comprises:
Low pass filter is electrically connected with described analog switch, and the pulse signal that described analog switch is exported carries out filtering.
3. audio frequency power amplifier as claimed in claim 1 system is characterized in that described preamplifier comprises:
First operational amplifier, second operational amplifier, first resistance, second resistance, the 3rd resistance, the 4th resistance, first electric capacity and second electric capacity;
The reversed-phase output of described first operational amplifier is connected to the in-phase input end of described first operational amplifier by first resistance;
The in-phase output end of described first operational amplifier is connected to the inverting input of described first operational amplifier by second resistance.
The reversed-phase output of described second operational amplifier is connected to the in-phase input end of described second operational amplifier by the 3rd resistance and first electric capacity;
The in-phase output end of described second operational amplifier is connected to the inverting input of described second operational amplifier by the 4th resistance and second electric capacity.
4. audio frequency power amplifier as claimed in claim 3 system is characterized in that described integrating circuit comprises:
The 3rd operational amplifier, the 3rd electric capacity and the 4th electric capacity;
The reversed-phase output of described the 3rd operational amplifier is connected to the in-phase input end of described the 3rd operational amplifier by the 3rd electric capacity;
The in-phase output end of described the 3rd operational amplifier is connected to the inverting input of described the 3rd operational amplifier by the 4th electric capacity.
5. audio frequency power amplifier as claimed in claim 4 system is characterized in that described first operational amplifier, described second operational amplifier and described the 3rd operational amplifier are the fully differential operational amplifier.
6. audio frequency power amplifier as claimed in claim 4 system is characterized in that described comparator comprises: first comparator and second comparator;
The in-phase input end of described first comparator is connected with the reversed-phase output of described the 3rd operational amplifier;
The in-phase input end of described second comparator is connected with the in-phase output end of described the 3rd operational amplifier;
The inverting input of the inverting input of described first comparator and described second comparator all is connected with described pulse width modulation carrier.
7. an audio frequency power amplifier is characterized in that, comprises a closed-loop D-class audio frequency power amplifier system, and this system comprises:
The preamplifier that input signal is adjusted;
Integrating circuit is electrically connected with described preamplifier;
Comparator is electrically connected with described integrating circuit, and signal and pulse width modulation carrier that described integrating circuit is exported compare;
Drive circuit is used to adjust pwm signal, drives late-class circuit;
The H-bridge circuit is as the system power output stage; And
Feedback loop feeds back to the output of H-bridge circuit the input of preamplifier amplifier.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2009201360009U CN201594809U (en) | 2009-03-27 | 2009-03-27 | Closed-loop D type audio amplifier system and audio amplifier |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2009201360009U CN201594809U (en) | 2009-03-27 | 2009-03-27 | Closed-loop D type audio amplifier system and audio amplifier |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN201594809U true CN201594809U (en) | 2010-09-29 |
Family
ID=42776874
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2009201360009U Expired - Fee Related CN201594809U (en) | 2009-03-27 | 2009-03-27 | Closed-loop D type audio amplifier system and audio amplifier |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN201594809U (en) |
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102832887A (en) * | 2012-09-11 | 2012-12-19 | 电子科技大学 | High-fidelity D type voice frequency amplifier |
| CN103501162A (en) * | 2013-09-29 | 2014-01-08 | 电子科技大学 | High-fidelity D-type audio frequency amplifier chip with noise canceller circuit |
| CN104485908A (en) * | 2014-11-14 | 2015-04-01 | 河北高达电子科技有限公司 | 1000w digital power amplifier |
| CN105024620A (en) * | 2014-04-22 | 2015-11-04 | 上海微电子装备有限公司 | Motor drive circuit eliminating output leakage current |
| CN105281683A (en) * | 2014-06-10 | 2016-01-27 | 台湾积体电路制造股份有限公司 | Class-d amplifier having mixed signal feedback control |
| CN106301258A (en) * | 2016-08-16 | 2017-01-04 | 严添明 | A kind of D-type audio power amplifier |
| CN110504928A (en) * | 2019-08-02 | 2019-11-26 | 武汉谐声半导体科技有限公司 | D class power amplifier powers on noise suppression circuit, method and apparatus |
| CN113541480A (en) * | 2021-09-15 | 2021-10-22 | 武汉市聚芯微电子有限责任公司 | Voltage-stabilizing power regulating circuit, power regulating device and electronic device |
| CN113783534A (en) * | 2021-09-15 | 2021-12-10 | 武汉市聚芯微电子有限责任公司 | Feedback type audio power amplifying circuit, audio amplifying device and electronic device |
| CN116614091A (en) * | 2023-07-21 | 2023-08-18 | 深圳前海深蕾半导体有限公司 | Plosive eliminating circuit of class D audio power amplifier |
-
2009
- 2009-03-27 CN CN2009201360009U patent/CN201594809U/en not_active Expired - Fee Related
Cited By (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102832887A (en) * | 2012-09-11 | 2012-12-19 | 电子科技大学 | High-fidelity D type voice frequency amplifier |
| CN103501162A (en) * | 2013-09-29 | 2014-01-08 | 电子科技大学 | High-fidelity D-type audio frequency amplifier chip with noise canceller circuit |
| CN105024620B (en) * | 2014-04-22 | 2018-10-16 | 上海微电子装备（集团）股份有限公司 | A kind of motor-drive circuit for eliminating output leakage current |
| CN105024620A (en) * | 2014-04-22 | 2015-11-04 | 上海微电子装备有限公司 | Motor drive circuit eliminating output leakage current |
| CN105281683A (en) * | 2014-06-10 | 2016-01-27 | 台湾积体电路制造股份有限公司 | Class-d amplifier having mixed signal feedback control |
| CN105281683B (en) * | 2014-06-10 | 2018-07-17 | 台湾积体电路制造股份有限公司 | Class-D amplifier with mixed signal feedback control |
| CN104485908B (en) * | 2014-11-14 | 2017-06-20 | 河北高达电子科技有限公司 | 1000W digital power amplifiers |
| CN104485908A (en) * | 2014-11-14 | 2015-04-01 | 河北高达电子科技有限公司 | 1000w digital power amplifier |
| CN106301258A (en) * | 2016-08-16 | 2017-01-04 | 严添明 | A kind of D-type audio power amplifier |
| CN106301258B (en) * | 2016-08-16 | 2018-08-28 | 严添明 | A kind of D-type audio power amplifier |
| CN110504928A (en) * | 2019-08-02 | 2019-11-26 | 武汉谐声半导体科技有限公司 | D class power amplifier powers on noise suppression circuit, method and apparatus |
| CN113541480A (en) * | 2021-09-15 | 2021-10-22 | 武汉市聚芯微电子有限责任公司 | Voltage-stabilizing power regulating circuit, power regulating device and electronic device |
| CN113783534A (en) * | 2021-09-15 | 2021-12-10 | 武汉市聚芯微电子有限责任公司 | Feedback type audio power amplifying circuit, audio amplifying device and electronic device |
| CN113783534B (en) * | 2021-09-15 | 2022-05-17 | 武汉市聚芯微电子有限责任公司 | Feedback type audio power amplifying circuit, audio amplifying device and electronic device |
| CN116614091A (en) * | 2023-07-21 | 2023-08-18 | 深圳前海深蕾半导体有限公司 | Plosive eliminating circuit of class D audio power amplifier |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN201594809U (en) | Closed-loop D type audio amplifier system and audio amplifier | |
| CN100586008C (en) | Switch amplifier and its modulation method | |
| CN102611964B (en) | Power amplification circuit and system | |
| CN101847968B (en) | High-performance D type audio power amplifier with high-order multipath feedback structure | |
| Jiang | Fundamentals of audio class D amplifier design: A review of schemes and architectures | |
| USRE42846E1 (en) | Close-loop class-D audio amplifier and control method thereof | |
| CN104702221B (en) | PWM power amplifier | |
| US8212612B2 (en) | Closed-loop class-D amplifier with modulated reference signal and related method | |
| US20110068870A1 (en) | Class-d amplifier with dual feedback loop | |
| Teplechuk et al. | Filterless integrated class-D audio amplifier achieving 0.0012% THD+ N and 96dB PSRR when supplying 1.2 W | |
| CN102013875A (en) | Digital power amplifier and control method thereof | |
| US20180041173A1 (en) | Configurable control loop topology for a pulse width modulation amplifier | |
| WO2002087076A3 (en) | Class d amplifier with passive rc network | |
| CN101459410A (en) | Class D amplifier | |
| Ido et al. | A digital input controller for audio class-D amplifiers with 100W 0.004% THD+ N and 113dB DR | |
| CN101741325A (en) | Class-D audio-frequency power amplifier with carrier wave adjustable module and carrier wave modulation method thereof | |
| CN204465463U (en) | PWM power amplifier | |
| KR100972155B1 (en) | Class-d amplifier providing dual feedback loop | |
| CN201860297U (en) | Class D audio power amplifier system | |
| Rojas-Gonzalez et al. | Two class-D audio amplifiers with 89/90% efficiency and 0.02/0.03% THD+ N consuming less than 1mW of quiescent power | |
| CN201797488U (en) | Novel digital input power amplifier | |
| CN212785275U (en) | Current feedback self-oscillation audio digital power amplifier | |
| CN101944887A (en) | Ended output type D-class amplifier of double-feedback differential circuit | |
| CN208433953U (en) | A kind of digital analog converter and digital power amplifier subsystem | |
| CN201550265U (en) | Hifi class D acoustics for automobile |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20100929 Termination date: 20160327 |
|
| CF01 | Termination of patent right due to non-payment of annual fee |