CN-122026823-A - Power amplifier efficiency improving method, system and capacitive load driving system

CN122026823ACN 122026823 ACN122026823 ACN 122026823ACN-122026823-A

Abstract

The invention discloses a power amplifier efficiency improving method, a system and a capacitive load driving system, which comprise the steps of sampling output voltage of a power amplifier in real time, calculating target power supply voltage required by the current working state of the power amplifier according to the output voltage, searching a pre-established lookup table to obtain a PWM waveform signal with a duty ratio corresponding to the target power supply voltage, converting the PWM waveform signal into an analog voltage signal and applying the analog voltage signal to a feedback end of a power supply module, and controlling the power supply module to output the corresponding target power supply voltage to the power amplifier, wherein the target power supply voltage is higher than the current maximum output voltage required by the power amplifier. According to the invention, the output voltage of the power amplifier is sampled in real time, and the output voltage is taken as a reference, so that the power supply voltage of the power amplifier is matched with the actual output requirement, and therefore, the signal integrity is ensured, the invalid voltage loss is reduced, the energy utilization rate is improved, and the power amplifier efficiency is remarkably improved.

Inventors

GU TIANLONG
WANG SHIRU
DONG YIHU

Assignees

苏州清听声学科技有限公司

Dates

Publication Date: 20260512
Application Date: 20251231

Claims (10)

1. A method of improving efficiency of a power amplifier, the method comprising: s1, sampling output voltage of a power amplifier in real time; s2, calculating a target power supply voltage required by the current working state of the power amplifier according to the output voltage, and searching a pre-established lookup table to obtain a PWM waveform signal of a duty ratio corresponding to the target power supply voltage; And S3, converting the PWM waveform signal into an analog voltage signal and applying the analog voltage signal to a feedback end of the power supply module, so as to control the power supply module to output the corresponding target power supply voltage to the power amplifier, wherein the target power supply voltage is higher than the maximum output voltage currently required by the power amplifier.
2. The power amplifier efficiency improvement method according to claim 1, wherein in S2, the lookup table is established in advance by an experimental manner, and the lookup table is a correspondence table between a target supply voltage of the power supply module and a PWM duty ratio.
3. The power amplifier efficiency improvement method according to claim 2, wherein in S2, the lookup table establishment process includes: and measuring the output voltage of the power supply module at intervals of a certain proportion in a PWM duty ratio range of 20% -80%, and obtaining the lookup table with PWM duty ratio corresponding to the target power supply voltage of the power supply module one by one.
4. A power amplifier efficiency improvement method according to claim 1 wherein in S3, said PWM waveform signal is converted to said analog voltage signal by low pass filtering and/or said low pass filtering is accomplished by two stage RC filtering.
5. A power amplifier efficiency improvement method according to claim 1 wherein S1 comprises performing a block and buck sampling of the AC signal output by the power amplifier to obtain a sampled signal proportional to the amplitude of the output voltage of the power amplifier.
6. The power amplifier efficiency improvement method according to claim 1, wherein in step S2, the target supply voltage is obtained by performing analog-to-digital conversion, filtering and calculation using a voltage algorithm on the output voltage.
7. A power amplifier efficiency enhancement system, comprising: the output voltage acquisition module is connected with the output end of the power amplifier and is used for sampling the output voltage of the power amplifier in real time; The PWM waveform signal acquisition module is connected with the output end of the output voltage acquisition module and is used for calculating a target power supply voltage required by the current working state of the power amplifier according to the output voltage and searching a pre-established lookup table to obtain a PWM waveform signal of a duty ratio corresponding to the target power supply voltage; The power supply output module is connected with the PWM waveform signal acquisition module and comprises a signal conversion module and a power supply module, wherein the signal conversion module is used for converting the PWM waveform signal into an analog voltage signal and applying the analog voltage signal to the feedback end of the power supply module, and the power supply module is used for outputting a corresponding target power supply voltage to the power amplifier, and the target power supply voltage is higher than the maximum output voltage currently required by the power amplifier.
8. The system of claim 7, wherein the lookup table is stored in the PWM waveform signal acquisition module, the lookup table is pre-established in an experimental manner, the lookup table is a table of correspondence between a target power supply voltage and a PWM duty cycle of the power supply module, and/or the establishment process of the lookup table includes measuring an output voltage of the power supply module at intervals of a duty cycle of a certain proportion within a PWM duty cycle range of 20% -80%, so as to obtain the lookup table with a one-to-one correspondence between the PWM duty cycle and the target power supply voltage of the power supply module.
9. A power amplifier efficiency enhancement system according to claim 7, wherein said signal conversion module comprises a low pass filter for converting said PWM waveform signal to said analog voltage signal and/or wherein said low pass filter is a two-stage RC filter.
10. A capacitive load driving system comprising a power amplifier efficiency enhancing system according to any of the preceding claims 7-9, wherein an output of the power amplifier is connected to an input of the capacitive load.

Description

Power amplifier efficiency improving method, system and capacitive load driving system Technical Field The invention relates to the technical field of power amplifiers, in particular to a power amplifier efficiency improving method, a power amplifier efficiency improving system and a capacitive load driving system. Background In practical applications, the supply voltage of a conventional power amplifier (hereinafter referred to as "power amplifier") is usually set to a fixed value, for example, 12V, 24V, etc., during the design stage. Once the supply voltage is determined, it remains substantially unchanged during use of the product. However, the working efficiency of the power amplifier is obviously different under different output voltage and output power states. In theory, when the voltage amplitude of the output signal of the power amplifier is close to the power supply voltage, the energy conversion efficiency of the power amplifier is highest, and when the output voltage is far lower than the power supply voltage, the redundant voltage is consumed in the power amplifier in a heat form, so that the efficiency is reduced. Taking a common audio power amplifier as an example, the maximum output power of the audio power amplifier may be designed to be 25W, but in a practical application scenario, the audio power amplifier only works in an output power range of 5W to 10W most of the time. Under the working condition, the power supply voltage is still maintained at the maximum design value, and the power amplification efficiency is only 60% -70%, so that larger invalid power consumption and heating value are generated, 1, the power amplification device is higher in temperature rise, the heat dissipation design difficulty is increased, 2, the overall power consumption of the system is increased, and the long-term reliability and consistency of the product are reduced. In addition, in some applications, loads driven by the power amplifier (such as loads with capacitive characteristics) have a certain difference between different products. To ensure output consistency, it is often necessary to provide a high and fixed supply margin, which further exacerbates the problem of inefficient operation of the power amplifier. Therefore, a scheme for dynamically adjusting the power supply voltage according to the actual working state of the power amplifier is needed to improve the power amplifier efficiency and reduce the heat dissipation of the system. Disclosure of Invention The invention aims to provide a power amplifier efficiency improving method, a power amplifier efficiency improving system and a capacitive load driving system, wherein the power amplifier efficiency can be improved, and heat dissipation of a system can be reduced. In order to achieve the above object, the present invention provides a method for improving efficiency of a power amplifier, comprising: s1, sampling output voltage of a power amplifier in real time; s2, calculating a target power supply voltage required by the current working state of the power amplifier according to the output voltage, and searching a pre-established lookup table to obtain a PWM waveform signal of a duty ratio corresponding to the target power supply voltage; And S3, converting the PWM waveform signal into an analog voltage signal and applying the analog voltage signal to a feedback end of the power supply module, so as to control the power supply module to output the corresponding target power supply voltage to the power amplifier, wherein the target power supply voltage is higher than the maximum output voltage currently required by the power amplifier. In a preferred embodiment, in S2, the lookup table is established in advance through an experiment, where the lookup table is a table of correspondence between the target supply voltage of the power supply module and the PWM duty cycle. In a preferred embodiment, in the step S2, the process of establishing the lookup table includes measuring the output voltage of the power supply module at intervals of a certain proportion of duty ratio within a PWM duty ratio range of 20% -80%, so as to obtain the lookup table with PWM duty ratio corresponding to the target power supply voltage of the power supply module one by one. In a preferred embodiment, in the step S3, the PWM waveform signal is converted into the analog voltage signal through low-pass filtering, and/or the low-pass filtering is implemented through two-stage RC filtering. In a preferred embodiment, the step S1 comprises the steps of blocking and down sampling the AC signal output by the power amplifier to obtain a sampled signal proportional to the amplitude of the output voltage of the power amplifier. In a preferred embodiment, in the step S2, the target supply voltage is obtained by performing analog-to-digital conversion, filtering and calculation using a voltage algorithm on the output voltage. On the other hand, the technical scheme disclosed by the inv