CN209497426U - A kind of HD Audio power amplification circuit - Google Patents

Abstract

The utility model discloses a kind of HD Audio power amplification circuits.The utility model carries out two-stage amplification to circuit using 2 LM324D amplifiers, and LM324D amplifier has the function of internal compensation, and short-circuit protection output, effectively can carry out voltage amplification to small signal by 121 times of overall magnification.Power amplifier is made of class AB power supply complementary symmetry circuit, can effectively overcome intermodulation distortion, and Q3 forms preamplifier state, and Q1 and Q2 form complementary output grade.When static, the pressure drop generated on D1, D2 provides a bias appropriate for Q1, Q2, is allowed in lightly conducting state.Due to circuit symmetrical, when having signal, since circuit works in class AB, even if input voltage very little, linear can substantially amplify.Therefore this power amplification circuit high gain, it is high-efficient, it is distorted small, output power, audio signal high-fidelity power amplification may be implemented.

Description

A kind of HD Audio power amplification circuit

Technical field:

The utility model relates to audio amplifier circuit technical field more particularly to a kind of HD Audio power amplification electricity Road.

Background technique:

Audio-frequency power amplifier is the quite mature field of a technology, and in decades, people have paid not for it No matter slack effort in terms of the Line technology or component or even in thought and knowledge all achieves significant progress.

The development of high-fidelity power amplifier technology makes entire Audio power amplifier technical field that huge variation have occurred. Modern is higher and higher to hearing level requirement, so requiring the sound quality authenticity of sound equipment more and more.But at present big Most audio-frequency power amplifiers still have the problem of component is more, at high cost, welding is difficult, audio signal distortion.

Utility model content:

The purpose of this utility model is to provide a kind of HD Audio power amplification circuits, to solve the prior art not Foot.

The utility model is implemented by following technical solution: a kind of HD Audio power amplification circuit, including preposition amplification Circuit and power amplification circuit, the pre-amplification circuit includes operation amplifier chip U1A and operation amplifier chip U3A, described The in-phase end of operation amplifier chip U1A connects audio signal input end, and the reverse side of the operation amplifier chip U1A connects resistance The one end R4, R5, the resistance R4 other end ground connection, the output end of the resistance R5 other end connection operation amplifier chip U1A, institute The output end for stating operation amplifier chip U1A is also connected with the in-phase end of operation amplifier chip U3A, the operation amplifier chip U3A's Reverse side connects the one end resistance R7, R8, states resistance R7 other end ground connection, and the resistance R8 other end connects operation amplifier chip The output end of U3A, the output end of the operation amplifier chip U3A connect power amplification circuit input terminal, the power amplification electricity Road includes NPN triode Q1, PNP triode Q2, Q3 and diode D1, D2, the output end of the operation amplifier chip U3A PNP triode Q3 base stage is connected, the PNP triode Q3 emitter passes through resistance R1 connection positive supply, the PNP triode Q3 Collector connects NPN triode Q1 base stage, connects between the NPN triode Q1 and the base stage of PNP triode Q2 and forward connects Diode D1, D2, wherein diode D1 anode connects NPN triode Q1 base stage, and diode D2 cathode connects PNP triode Q2 base Pole, the NPN triode Q1 collector connect positive supply, and the NPN triode Q1 emitter and PNP triode Q2 emitter are logical Capacitor C1 connection load resistance R3 is crossed, the PNP triode Q2 collector connects negative supply, the PNP triode Q2 collector Resistance R2 is connected between base stage.

Preferably, the operation amplifier chip U1A and operation amplifier chip U3A model LM324D.

Preferably, the NPN triode Q1 model 2N1711, PNP triode Q2, the Q3 model 2N2905.

Preferably, the positive supply is 24V DC voltage, and the negative supply is -24V DC voltage.

The advantages of the utility model:

The utility model carries out two-stage amplification to circuit using 2 LM324D amplifiers, and LM324D amplifier has internal compensation Function, short-circuit protection output, effectively can carry out voltage amplification to small signal by 121 times of overall magnification.Power amplifier by Class AB power supply complementary symmetry circuit is constituted, and can effectively overcome intermodulation distortion, and Q3 forms preamplifier state, and Q1 and Q2 composition are mutual Mend output stage.When static, the pressure drop generated on D1, D2 provides a bias appropriate for Q1, Q2, is allowed in lightly conducting State.Due to circuit symmetrical, when having signal, since circuit work substantially can be linear even if input voltage very little in class AB Amplify.Therefore this power amplification circuit high gain, it is high-efficient, it is distorted small, output power, audio letter may be implemented Number high-fidelity power amplification.

Detailed description of the invention:

In order to illustrate the embodiment of the utility model or the technical proposal in the existing technology more clearly, below will be to embodiment Or attached drawing needed to be used in the description of the prior art is briefly described, it should be apparent that, the accompanying drawings in the following description is only It is some embodiments of the utility model, for those of ordinary skill in the art, in the premise not made the creative labor Under, it is also possible to obtain other drawings based on these drawings.

Fig. 1 is the circuit diagram of the utility model.

Specific embodiment:

The following will be combined with the drawings in the embodiments of the present invention, carries out the technical scheme in the embodiment of the utility model Clearly and completely describe, it is clear that the described embodiments are only a part of the embodiments of the utility model, rather than whole Embodiment.Based on the embodiments of the present invention, those of ordinary skill in the art are without creative efforts Every other embodiment obtained, fall within the protection scope of the utility model.

As shown in Figure 1, a kind of HD Audio power amplification circuit, including pre-amplification circuit and power amplification circuit, Pre-amplification circuit includes operation amplifier chip U1A and operation amplifier chip U3A, the in-phase end connection of operation amplifier chip U1A Audio signal input end, the reverse side of operation amplifier chip U1A connect the one end resistance R4, R5, resistance R4 other end ground connection, resistance The R5 other end connects the output end of operation amplifier chip U1A, and the output end of operation amplifier chip U1A is also connected with operation amplifier chip The reverse side of the in-phase end of U3A, operation amplifier chip U3A connects the one end resistance R7, R8, states resistance R7 other end ground connection, resistance The R8 other end connects the output end of operation amplifier chip U3A, and the output end connection power amplification circuit of operation amplifier chip U3A is defeated Enter end, power amplification circuit includes NPN triode Q1, PNP triode Q2, Q3 and diode D1, D2, operation amplifier chip The output end of U3A connects PNP triode Q3 base stage, and PNP triode Q3 emitter passes through resistance R1 connection positive supply, tri- pole PNP Pipe Q3 collector connects NPN triode Q1 base stage, connects between NPN triode Q1 and the base stage of PNP triode Q2 and forward connects Diode D1, D2, wherein diode D1 anode connects NPN triode Q1 base stage, and diode D2 cathode connects PNP triode Q2 base Pole, NPN triode Q1 collector connect positive supply, and NPN triode Q1 emitter and PNP triode Q2 emitter pass through capacitor C1 Load resistance R3 is connected, PNP triode Q2 collector connects negative supply, and electricity is connected between PNP triode Q2 collector and base stage Hinder R2.

Wherein, operation amplifier chip U1A and operation amplifier chip U3A model LM324D.NPN triode Q1 model 2N1711, PNP triode Q2, Q3 model 2N2905.Positive supply is 24V DC voltage, and negative supply is -24V DC voltage.

As shown in Figure 1, pre-amplification circuit completes the voltage amplification task of the small signal of audio, improves signal-to-noise ratio.The distortion factor With noise to the influence maximum for being its system, being should top-priority index.The design using 2 LM324D amplifiers to circuit into The amplification of row two-stage, LM324D amplifier have the function of internal compensation, short-circuit protection output.First order amplification factor is Av1=1+R5/ R4=11, second level amplification factor be Av2=1+R8/R7=11,121 times of overall magnification, can effectively to small signal into Row voltage amplification.

Power amplifier is made of class AB power supply complementary symmetry circuit, before can effectively overcoming intermodulation distortion, Q3 to form Amplifying stage is set, Q1 and Q2 form complementary output grade.When static, the pressure drop generated on D1, D2 provides one suitably for Q1, Q2 Bias, be allowed in lightly conducting state.Due to circuit symmetrical, when having signal, since circuit work is in class AB, even if input Voltage very little linear can substantially amplify.Therefore this power amplification circuit high gain, it is high-efficient, it is distorted small, output Power is big, and audio signal high-fidelity power amplification may be implemented.

The above is only the preferred embodiment of the utility model only, is not intended to limit the utility model, all at this Within the spirit and principle of utility model, any modification, equivalent replacement, improvement and so on should be included in the utility model Protection scope within.

Claims (4)

1. a kind of HD Audio power amplification circuit, which is characterized in that including pre-amplification circuit and power amplification circuit, institute Stating pre-amplification circuit includes operation amplifier chip U1A and operation amplifier chip U3A, the same phase of the operation amplifier chip U1A End connection audio signal input end, the reverse side of the operation amplifier chip U1A connect the one end resistance R4, R5, the resistance R4 Other end ground connection, the output end of the resistance R5 other end connection operation amplifier chip U1A, the operation amplifier chip U1A's Output end is also connected with the in-phase end of operation amplifier chip U3A, and the reverse side of the operation amplifier chip U3A connects resistance R7, R8 Resistance R7 other end ground connection, the output end of the resistance R8 other end connection operation amplifier chip U3A, the operation are stated in one end The output end of amplification chip U3A connects power amplification circuit input terminal, and the power amplification circuit includes NPN triode Q1, PNP Triode Q2, Q3 and diode D1, D2, the output end of the operation amplifier chip U3A connect PNP triode Q3 base stage, institute PNP triode Q3 emitter is stated by resistance R1 connection positive supply, the PNP triode Q3 collector connects NPN triode Q1 Base stage connects forward concatenated diode D1, D2, wherein two poles between the NPN triode Q1 and the base stage of PNP triode Q2 Pipe D1 anode connects NPN triode Q1 base stage, and diode D2 cathode connects PNP triode Q2 base stage, the NPN triode Q1 collector Positive supply is connect, the NPN triode Q1 emitter passes through capacitor C1 with PNP triode Q2 emitter and connects load resistance R3, The PNP triode Q2 collector connects negative supply, and resistance R2 is connected between the PNP triode Q2 collector and base stage.

2. a kind of HD Audio power amplification circuit according to claim 1, which is characterized in that the operation amplifier core Piece U1A and operation amplifier chip U3A model LM324D.

3. a kind of HD Audio power amplification circuit according to claim 1, which is characterized in that the NPN triode Q1 model 2N1711, PNP triode Q2, the Q3 model 2N2905.

4. a kind of HD Audio power amplification circuit according to claim 1, which is characterized in that the positive supply is 24V DC voltage, the negative supply are -24V DC voltage.