CN213879756U

CN213879756U - Low-power consumption instant-use constant-voltage power amplifier system controlled by DSP

Info

Publication number: CN213879756U
Application number: CN202022947490.XU
Authority: CN
Inventors: 唐寅寅; 张晨
Original assignee: Nanjing Tuotu Electronics Co ltd
Current assignee: Nanjing Tuotu Electronics Co ltd
Priority date: 2020-12-11
Filing date: 2020-12-11
Publication date: 2021-08-03
Anticipated expiration: 2030-12-11

Abstract

The utility model discloses a constant voltage power amplifier system who uses is taken promptly to DSP controlled low-power consumption is applicable to public broadcasting, including data communication module, DSP processing module, standby module and power amplification module. The data communication module comprises a receiving circuit, an audio isolation transformer, a signal detection circuit and a signal transmission circuit, wherein the receiving circuit receives an external sound source signal and outputs the external sound source signal to the DSP processing module. The input of the DSP processing module is the output of the data communication module and the judgment output of the standby module, and the output is connected with the power amplification module after signal processing. The standby module is connected with the output end of the signal detection circuit and the output end of the power amplification module and controls the power amplification module to start and stop and judge the load. The power amplification module receives the signal processed by the DSP processing module, amplifies the signal to a power supply rail according to the control of the standby module, and is directly connected with a load for output. The utility model discloses utilize DSP and little the control unit cooperation to carry out signal processing and system control, more nimble, the response is rapid.

Description

Low-power consumption instant-use constant-voltage power amplifier system controlled by DSP

Technical Field

The utility model relates to a level pressure power amplifier field, concretely relates to low-power consumption of DSP control is taken the level pressure power amplifier system of usefulness promptly.

Background

In the prior art, because a class D modulation amplification technology is adopted, distortion and noise generated by a common constant voltage power amplifier during normal amplification are almost inaudible, but in contrast, in a standby state, due to the problems of the layout and topology of an electronic circuit, background noise is generated, and the principle improvement cannot be made, so that standby noise is inevitably generated, and the practical use is influenced. The use of the constant voltage power amplifier is continuous and discontinuous, the power amplifier usually needs to work for tens of hours, but the power amplifier is not always accessed by a sound source, and the constant voltage power amplifier is in a standby state for a long time when no sound source is accessed, so that the power consumption is considerable.

Because level pressure power amplifier mainly used public place broadcasting, it is higher to taking the requirement of usefulness promptly, current broadcast level pressure power amplifier can appear leaking the condition of word because start-up needs time, takes promptly, can make by broadcaster's unable acquisition whole broadcast information, can threaten by broadcaster's the security of the lives and property even under the emergency.

With the development of technology, the integration degree of a digital audio processor in the future is higher and higher, and various use requirements and functional requirements of users for audio products cannot be met only by adopting an analog design, so that the embedding of a DSP chip into the audio products becomes necessary.

Therefore, in order to reduce the energy consumption of the constant voltage power amplifier, improve the use effect, and meet the technical development trend, it is necessary to provide a DSP-controlled constant voltage power amplifier with low power consumption and ready-to-use.

Disclosure of Invention

In view of the above, the present invention provides a fully isolated, embedded DSP chip controlled, low power consumption, instant-use, constant voltage power amplifier system.

The utility model discloses a DSP controlled low-power consumption is taken constant voltage power amplifier system of usefulness promptly, is applicable to public transport, public occasion's broadcast, and it includes data communication module, DSP processing module, standby module and power amplification module. The data communication module comprises a receiving circuit, an audio isolation transformer, a signal detection circuit and a signal transmission circuit, wherein the receiving circuit receives an external sound source signal, and outputs the external sound source signal to the DSP processing module after isolation and transmission processing. The input end of the DSP processing module is connected with the output end of the data communication module and one output end of the standby module to process signals of the sound source, and the output end of the DSP processing module is connected with the power amplification module. The standby module is connected with an output signal of the signal detection circuit and an output end of the power amplification module, and controls the power amplification module to start and stop and carry out load judgment. The power amplification module receives the signal processed by the DSP processing module, and amplifies the signal to a power supply rail according to the control of the standby module after the signal passes through the internal coupling circuit, so that the power amplification module is directly connected with a load for output without an output step-up transformer.

The data communication module comprises a receiving circuit, an audio isolation transformer, a signal detection circuit and a signal transmission circuit, and is used for receiving external sound source signals, carrying out input and output isolation and detecting whether a sound source exists. The receiving circuit comprises an analog receiving port and a Bluetooth module, the analog receiving port is in wired connection, and a sound source is connected with the analog receiving port through a transmission line; the Bluetooth module can carry out wireless Bluetooth transmission after being paired with a sound source. The output end of the analog receiving port is connected with the primary side of the audio isolation transformer, and the secondary side of the analog receiving port is connected with the signal transmission circuit and the signal detection circuit. The signal detection circuit comprises two operational amplifier circuits, wherein the in-phase input ends of the two operational amplifier circuits are respectively connected with the output of the audio isolation transformer and the output of the Bluetooth module, the two operational amplifier circuits are amplified in phase, and the outputs are respectively connected to the same input end of the standby module through a diode. The signal transmission circuit comprises two operational amplifier circuits, wherein the in-phase input ends of the two operational amplifier circuits are respectively connected with the output of the audio isolation transformer and the output of the Bluetooth module, the two operational amplifier circuits are amplified in phase, and the output of the operational amplifier is connected with two input pins of the DSP processing module.

The DSP processing module comprises a special audio DSP chip and a matched circuit thereof and is used for carrying out digital processing on an input sound source and carrying out starting control on a system. And the processing module in the DSP chip is mainly divided into a gain control module and a switching module. The gain control module is a noise threshold with gain control and is used for actively reducing background noise, firstly, analog-to-digital conversion is carried out on an input signal, then, signal detection is carried out, and the internal gain of the DSP is automatically adjusted according to the signal amplitude and the duration: setting a minimum threshold V1 and a minimum threshold T1 of duration of the sound source signals, and preferentially setting gains according to signal amplitudes, namely adopting default amplification gains no matter the duration when the signal amplitudes exceed the minimum threshold V1; when the signal amplitude is below the minimum threshold V1, the default gain is reduced if the duration exceeds the minimum threshold T1. The digital sound source signal processed by the gain control module is subjected to general processing such as dynamic compression, noise suppression, filtering and the like, digital-to-analog conversion is carried out, and the digital sound source signal is connected to the input end of the power amplification module through the output end of the DSP chip. The switching module is used for switching between a constant voltage mode and a constant resistance mode, and the signal gain of the DSP processing module is defaulted to be the gain of the constant voltage mode when the DSP processing module is powered on; and immediately generating a test signal by the DSP chip when the system is powered on, wherein the frequency of the test signal is more than 18kHz, and the amplitude is more than a minimum threshold V1 and less than the maximum output of the audio DSP signal. The standby module sends a load judgment result to the DSP processing module, and if the judgment result is a constant resistance load, the DSP processing module reduces the internal gain; and if the judgment result is the constant voltage load, the DSP processing module keeps the gain unchanged.

The standby module comprises a micro control unit and a matched circuit thereof and is used for controlling the mute, standby and load identification of the power amplification system, and the functions are realized by the micro control unit alone because the micro control unit has short trigger time and better power consumption cost than a DSP. The input end of the micro control unit is connected with the output signal of the signal detection circuit, the amplitude and the duration of the detection signal are preset with a minimum threshold V2, a mute threshold T2 and a standby threshold T3, V2< V1, T3> T2> T1, and a control instruction is preferentially sent according to the signal amplitude. When the signal amplitude is less than a minimum threshold V2 and the duration exceeds a mute threshold T2 and is less than a standby threshold T3, the micro control unit sends a mute instruction to the power amplification module and turns off the input end of the power amplification module; when the signal amplitude is smaller than the minimum threshold V2 and the duration exceeds the standby threshold T3, the micro control unit sends a standby instruction to the power amplification module and controls the power amplification module to enter a standby state. When the power amplification module is in a mute or standby state, if the micro control unit detects that the amplitude of the signal is greater than the minimum threshold V2, no matter how short the duration is, the micro control unit sends an instruction of recovering normal operation to the power amplification module, that is, the mute or standby state is removed. When the system is powered on, the DSP processing module generates a test signal, the micro control unit detects the voltage and the current of the output end of the power amplification module, judges the load type after calculation, and sends a judgment result to the DSP processing module; and if the load is judged to be the constant-resistance load, simultaneously sending a current-limiting switching signal to the power amplification module.

The power amplification module comprises a coupling circuit and a power amplification circuit, and is used for receiving and amplifying the signals processed by the DSP processing module and connecting the signals to a load for output. The coupling circuit couples the output signal of the DSP processing module to the input end of the power amplifying circuit in a resistance-capacitance coupling mode. The power amplifying circuit comprises a pulse width modulation circuit, a power level circuit, a filter circuit and a current limiting circuit. The pulse width modulation circuit performs pulse width modulation on an input signal to generate a PWM signal with a variable duty ratio; the power stage circuit drives a power stage MOSFET switch by a driving chip according to the PWM signal so as to generate the PWM signal amplified to a power supply rail; the filter circuit filters high-frequency components in the PWM signals amplified to the power supply rail, and restores original input signals so as to be connected with load output; the current limiting circuit adopts a programmable gain amplifier to adjust a current limiting value, defaults to constant voltage current limiting when the current limiting circuit is powered on, and sends a switching instruction to the programmable gain amplifier to improve the current limiting value if the micro control unit judges that a load is a constant resistance load.

Preferably, when the power amplification module is in a mute state, the micro control unit immediately sends an instruction for releasing the mute state to the power amplification module as soon as detecting that the amplitude of the signal is greater than a minimum threshold V2; when the power amplification module is in a standby state, once the micro control unit detects that the amplitude of the signal is greater than a minimum threshold V2, a command for releasing the standby state is sent to the power amplification module only after time delay, wherein the time delay is a time constant of the coupling circuit adopting a resistance-capacitance coupling mode.

The utility model discloses in a low-power consumption of DSP control take level pressure power amplifier system of usefulness promptly, utilize DSP and little the control unit cooperation to adopt to reduce the consumption when reducing gain, silence, standby means reduction background noise stage by stage when no sound source input, increase operational reliability. The micro control unit is used for controlling the turn-on sequence of the power amplifier during standby, so that the phenomenon of word leakage of the constant voltage power amplifier during use is effectively prevented, and POP sound is effectively eliminated. The power amplifier can be switched to a constant impedance mode for use on the basis of a constant voltage power amplifier, and is adaptive to wider loads. The system adopts the DSP to process signals, is more flexible and small compared with an analog signal processing circuit, can expand functions as required, and provides more possibilities for users.

In order to make the above and other objects of the present invention more comprehensible, preferred embodiments accompanied with figures are described in detail below.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are required to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention, and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.

Fig. 1 is a schematic block diagram of a DSP-controlled low-power consumption, ready-to-use, constant-voltage power amplifier system according to the present invention;

fig. 2 is a schematic circuit diagram of a data communication module of a DSP-controlled low-power consumption, ready-to-use, constant-voltage power amplifier system according to the present invention;

fig. 3 is a schematic circuit diagram of the power amplifying circuit in the power amplifying module of the DSP-controlled low-power consumption, ready-to-use, constant-voltage power amplifier system according to the present invention;

numbering in the figures:

10: a data communication module; 20: a DSP processing module; 30: a standby module;

40: a power amplification module; 101: a receiving circuit; 102: an audio isolation transformer;

103: a signal detection circuit and a signal transmission circuit; 1031: a signal detection circuit;

1032: a signal transmission circuit; 401: a power amplifier circuit.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. The components of embodiments of the present invention, as generally described and illustrated in the figures herein, may be arranged and designed in a wide variety of different configurations. Thus, the following detailed description of the embodiments of the present invention, presented in the accompanying drawings, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention.

Referring to fig. 1, a schematic block diagram of a DSP-controlled low-power consumption, ready-to-use, constant-voltage power amplifier system according to the present invention includes a data communication module 10, a DSP processing module 20, a standby module 30, and a power amplification module 40. The data communication module 10 comprises a receiving circuit 101, an audio isolation transformer 102, a signal detection circuit and a signal transmission circuit 103, wherein the receiving circuit 101 receives an external sound source signal, and outputs the external sound source signal to the DSP processing module 20 after isolation and transmission processing. The input end of the DSP processing module 20 is connected to the output of the data communication module 10 and the output end of the standby module 30, and is used for performing signal processing and controlling system start and stop for the sound source, and the output end is connected to the power amplification module 40. The standby module 30 is connected to the output signal of the signal detection circuit and the detection signal of the output end of the power amplification module 40, and controls the start and stop of the power amplification module 40. The power amplification module 40 receives the signal processed by the DSP processing module 20, amplifies the signal to a power rail according to the control of the standby module 30 after passing through an internal coupling circuit, and directly connects to a load output without an output step-up transformer.

Please refer to fig. 2, which is a schematic circuit diagram of a data communication module 10 of a DSP-controlled constant-voltage power amplifier system with low power consumption and ready-to-use. The data communication module 10 includes a receiving circuit, an audio isolation transformer 102, a signal detection circuit 1031, and a signal transmission circuit 1032, and is configured to receive an external sound source signal, perform input/output isolation, and detect whether a sound source exists. The receiving circuit comprises an analog receiving port 1011 and a Bluetooth module 1012, wherein the analog receiving port 1011 is in wired connection, and a sound source is connected with the analog receiving port 1011 through a transmission line; the bluetooth module 1012 can perform wireless bluetooth transmission after being paired with the sound source. The output end of the analog receiving port 1011 is connected to the primary side of the audio isolation transformer 102, and the secondary side is connected to the signal transmission circuit 1032 and the signal detection circuit 1031. The signal detection circuit 1031 includes two operational amplifier circuits A3 and a4, the non-inverting input terminals of A3 and a4 are respectively connected to the output of the audio isolation transformer 102 and the output of the bluetooth module 1012, the non-inverting inputs terminals of A3 and a4 are amplified in the non-inverting mode, and the outputs are respectively connected to the same input terminal of the standby module 30 through a diode. The signal transmission circuit 1032 comprises two operational amplifier circuits a1 and a2, wherein non-inverting input terminals of a1 and a2 are respectively connected with an output of the audio isolation transformer 102 and an output of the bluetooth module 1012, non-inverting amplifiers are respectively adopted for a1 and a2, and outputs of the A1 and the A2 are connected with two input pins of the DSP processing module 20.

Please refer to fig. 3, which is a schematic circuit diagram of the power amplifying circuit in the power amplifying module of the DSP controlled constant voltage power amplifier system with low power consumption and ready to use. The power amplification circuit 402 includes a pulse width modulation circuit 4021, a power stage circuit 4022, a filter circuit 4023, and a programmable gain amplifier 4024. The resistor R1 is used to detect the output end current, and the programmable gain amplifier 4024 is used to switch the current limiting value according to the instruction of the standby module 30, and the current limiting value is default to the current limiting value in the constant voltage mode, and is controlled by the switching instruction of the standby module 30, and if the current limiting value is the constant resistance load, the current limiting value is increased.

The above only is the embodiment of the present invention, not limiting the patent scope of the present invention, all the equivalent structures or equivalent processes that are used in the specification and the attached drawings or directly or indirectly applied to other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A constant-voltage power amplifier system controlled by DSP and having low power consumption and ready to use is characterized by comprising a data communication module, a DSP processing module, a standby module and a power amplification module; the data communication module comprises a receiving circuit, an audio isolation transformer, a signal detection circuit and a signal transmission circuit, wherein the receiving circuit receives an external sound source signal, and outputs the external sound source signal to the DSP processing module after isolation and transmission processing; the input end of the DSP processing module is connected with the output of the data communication module and one output end of the standby module to process signals of a sound source, and the output end of the DSP processing module is connected with the power amplification module; the standby module is connected with an output signal of the signal detection circuit and an output end of the power amplification module, and is used for controlling the start and stop of the power amplification module and carrying out load judgment; the power amplification module receives the signal processed by the DSP processing module, and amplifies the signal to a power supply rail according to the control of the standby module after the signal passes through the internal coupling circuit, so that the power amplification module is directly connected with a load for output without an output step-up transformer.

2. The DSP controlled, low power consumption, ready to use, fixed voltage power amplifier system of claim 1 wherein said receiver circuit includes an analog receiver port and a bluetooth module, said analog receiver port is wired, and an audio source is connected to said analog receiver port via a transmission line; the Bluetooth module is matched with the sound source to perform wireless Bluetooth transmission; the output end of the analog receiving port is connected with the primary side of the audio isolation transformer, and the secondary side of the analog receiving port is connected with the signal transmission circuit and the signal detection circuit; the signal detection circuit comprises two operational amplifier circuits, wherein the non-inverting input ends of the two operational amplifier circuits are respectively connected with the output of the audio isolation transformer and the output of the Bluetooth module, the two operational amplifier circuits adopt non-inverting amplification, and the outputs of the two operational amplifier circuits are respectively connected to the same input end of the standby module through a diode; the signal transmission circuit comprises two operational amplifier circuits, wherein the in-phase input ends of the two operational amplifier circuits are respectively connected with the output of the audio isolation transformer and the output of the Bluetooth module, the two operational amplifier circuits are amplified in phase, and the output of the operational amplifier is connected with two input pins of the DSP processing module.

3. The DSP controlled, low power consumption, ready to use, constant voltage power amplifier system of claim 1 wherein said DSP processing module includes a dedicated audio DSP chip and its associated circuitry; the processing module in the DSP chip is mainly divided into a gain control module and a switching module; the gain control module is a noise threshold with gain control and is used for selecting default gain or reduced gain to amplify the input signal according to the signal amplitude and duration, and the output of the gain control module is connected to the input end of the power amplification module; and the switching module is used for switching the gain in a constant voltage mode and a constant resistance mode according to the load judgment result of the standby module when the power is on.

4. The DSP controlled, low power consumption, ready to use, constant voltage power amplifier system of claim 1 wherein said standby module comprises a micro control unit and its associated circuitry; the input end of the micro control unit is connected with the output signal of the signal detection circuit, detects the amplitude and duration of the signal and is used for sending a mute instruction, a standby instruction and an instruction for recovering normal operation to the power amplification module according to the amplitude and duration of the signal; the micro control unit is also used for detecting the voltage and the current of the output end of the power amplification module, judging the load type after calculation, and sending the judgment result to the DSP processing module and the power amplification module.

5. The DSP-controlled, low-power, ready-to-use, constant voltage power amplifier system as set forth in claim 4, wherein said power amplification module includes a coupling circuit and a power amplification circuit, connected to the load output; the coupling circuit couples the output signal of the DSP processing module to the input end of the power amplifying circuit in a resistance-capacitance coupling mode; the power amplifying circuit comprises a pulse width modulation circuit, a power level circuit, a filter circuit and a current limiting circuit; the pulse width modulation circuit performs pulse width modulation on an input signal to generate a PWM signal with a variable duty ratio; the power stage circuit drives a power stage MOSFET switch by a driving chip according to the PWM signal so as to generate the PWM signal amplified to a power supply rail; the filter circuit filters high-frequency components in the PWM signals amplified to the power supply rail, and restores original input signals so as to be connected with load output; the current limiting circuit adopts a programmable gain amplifier to adjust a current limiting value, defaults to constant voltage current limiting when the current limiting circuit is powered on, and sends a switching instruction to the programmable gain amplifier to improve the current limiting value if the micro control unit judges that a load is a constant resistance load.