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CN-121984350-A - Stepless dynamic boost control method and system for audio signal following

CN121984350ACN 121984350 ACN121984350 ACN 121984350ACN-121984350-A

Abstract

The invention provides a stepless dynamic boost control method with an audio following function, which is applied to a boost circuit module for supplying power to an audio power amplifier and comprises the following steps of S1, collecting positive signals of all channels of multipath audio driving signals between the power amplifier module and a sounding unit, which are output by the power amplifier module in the audio power amplifier, extracting a maximum voltage amplitude Vsin in the multipath audio driving signals, S2, generating dynamic control current positively correlated with the difference value according to the difference value of the current power supply voltage PVDD output by the boost circuit module and the maximum voltage amplitude Vsin, S3, generating regulating current ICTRL after filtering the dynamic control current, injecting the regulating current ICTRL into a feedback pin FB of the boost circuit module, and S4, linearly and steplessly adjusting the output power supply voltage PVDD by the boost circuit module based on the regulating current ICTRL injected into the feedback pin FB, so that the power supply voltage PVDD follows the amplitude change of the audio driving signals in real time.

Inventors

  • QIN PENGJU
  • WU JINRONG
  • Peng Qunyun
  • WANG FUYU

Assignees

  • 宏熙半导体(无锡)有限公司

Dates

Publication Date
20260505
Application Date
20260311

Claims (10)

  1. 1. The stepless dynamic boost control method with the audio following function is applied to a boost circuit module for supplying power to an audio power amplifier and is characterized by comprising the following steps of: S1, collecting positive signals of all channels of multi-channel audio driving signals between a power amplifier circuit module and a sounding unit, which are output by the power amplifier circuit module in an audio power amplifier, and extracting a maximum voltage amplitude Vsin in the multi-channel audio driving signals; s2, generating dynamic control current positively correlated with a difference value of the current output power supply voltage PVDD of the boost circuit module and the maximum voltage amplitude Vsin; S3, after filtering the dynamic control current, generating an adjusting current ICTRL and injecting the adjusting current ICTRL into a feedback pin FB of the boost circuit module; And S4, the booster circuit module linearly and steplessly adjusts the output power supply voltage PVDD based on the adjusting current ICTRL injected into the feedback pin FB, so that the power supply voltage PVDD follows the amplitude change of the audio driving signal in real time.
  2. 2. The stepless dynamic boost control method with audio following function according to claim 1, wherein: in step S2, the dynamic control current satisfies the relation i=k× (PVDD-Vsin); Wherein k is a preset proportionality coefficient, PVDD is the current power supply voltage output by the boost circuit module, and Vsin is the maximum voltage amplitude value in the multipath audio driving signal.
  3. 3. The stepless dynamic boost control method with audio following function according to claim 1, wherein: in step S4, the supply voltage PVDD output by the boost circuit module satisfies the relation pvdd=pvdd_set-ictrl×rup; The PVDD_SET is a reference SET output voltage of the booster circuit module, ICTRL is an adjusting current injected into the feedback pin FB, and Rup is a resistance value of a voltage dividing resistor on the feedback end of the booster circuit module.
  4. 4. The stepless dynamic boost control method with audio following function according to claim 1, wherein: In step S4, when the amplitude of the audio driving signal increases, the difference between the power supply voltage PVDD and the maximum voltage amplitude Vsin decreases, the dynamic control current decreases synchronously, the generated adjusting current ICTRL decreases synchronously after the filtering processing, and the power supply voltage PVDD outputted by the boost circuit module increases linearly; When the amplitude of the audio driving signal is reduced, the difference between the power supply voltage PVDD and the maximum voltage amplitude Vsin is increased, the dynamic control current is synchronously increased, the generated adjusting current ICTRL is synchronously increased after the filtering processing, and the power supply voltage PVDD output by the booster circuit module is linearly reduced.
  5. 5. The stepless dynamic boost control system with the audio following function is suitable for the method of any one of claims 1-4, and is characterized by comprising a power supply module, a boost circuit module, a power amplifier circuit module, a controller circuit module, an output filter module and a feedback network module; the booster circuit module is provided with a feedback pin FB, the input end of the feedback pin FB is connected with the output voltage of the power supply module, and the output end of the feedback pin FB is connected with the power supply end of the power amplifier circuit module and is used for providing an adjustable power supply voltage PVDD for the power amplifier circuit module; The input end of the power amplifier circuit module is connected with an original audio signal, the output end of the power amplifier circuit module is used for being connected with a sounding unit, and the positive output end of each sound channel of the power amplifier circuit module is electrically connected with the sampling input end of the controller circuit module; The output end of the controller circuit module is electrically connected with the input end of the output filter module and is used for collecting the multipath audio driving signals output by the power amplifier circuit module, extracting the maximum voltage amplitude Vsin in the multipath audio driving signals and outputting a control current signal positively correlated with the difference value between the power supply voltage PVDD and the maximum voltage amplitude Vsin; the output end of the output filtering module is electrically connected with the feedback pin FB of the boost circuit module and is used for generating an adjusting current ICTRL injected into the feedback pin FB after filtering the control current signal; the feedback network module is connected between the output end of the boost circuit module and the feedback pin FB and is used for providing output voltage feedback for the boost circuit module; The output power supply voltage PVDD of the boost circuit module is in linear stepless change along with the magnitude of the regulating current ICTRL, and the amplitude of the power supply voltage PVDD and the amplitude of the audio driving signal output by the power amplifier circuit module are followed in real time.
  6. 6. The system of claim 5, further comprising an audio power module and an audio module, The input end of the audio power supply module is connected with the voltage of the power supply module, and the output end of the audio power supply module is connected with the power supply end of the audio module and is used for providing a working power supply DVDD for the audio module; The output end of the audio frequency module is connected with the input end of the power amplifier circuit module and is used for processing the input audio frequency signal and outputting the original audio frequency signal to the power amplifier circuit module.
  7. 7. The stepless dynamic boost control system with audio following function of claim 5, wherein: The feedback network module comprises an upper voltage dividing resistor Rup and a lower voltage dividing resistor Rdown, wherein the upper voltage dividing resistor Rup is connected in series between the output end of the boost circuit module and the feedback pin FB, the lower voltage dividing resistor Rdown is connected in series between the feedback pin FB and the ground, the reference of the boost circuit module SETs the output voltage PVDD_SET= (1+Rup/Rdown) multiplied by VSET, Wherein VSET is the fixed reference voltage of feedback pin FB of the boost circuit module, rup is the resistance of the upper voltage dividing resistor, rdown is the resistance of the lower voltage dividing resistor.
  8. 8. The stepless dynamic boost control system with audio following function of claim 5, wherein: The control current signal output by the controller circuit module satisfies the relation of I=kX (PVDD-Vsin); wherein k is a preset proportionality coefficient, PVDD is the output power supply voltage of the boost circuit module, and Vsin is the maximum voltage amplitude value in the multipath audio driving signal.
  9. 9. The stepless dynamic boost control system with audio following function of claim 5, wherein: The output filter module is a low-pass filter circuit LPF, and the boost circuit module is a DC-DC boost chip with a feedback pin FB.
  10. 10. The stepless dynamic boost control system with audio following function of claim 5, wherein: the minimum value of the power supply voltage PVDD output by the voltage boosting circuit module is not lower than the minimum working voltage of the power supply module, so that the voltage boosting circuit module always works in a voltage boosting mode.

Description

Stepless dynamic boost control method and system for audio signal following Technical Field The invention belongs to the technical field of audio electronics, in particular to a CLASS H audio power amplification technology, and particularly relates to a stepless dynamic boost control method and system for audio signal following. Background Along with the rapid popularization of portable audio playing devices (such as bluetooth sound equipment, outdoor portable sound boxes, intelligent voice devices and the like), users have put forward higher and higher requirements on audio output power, playing tone quality, duration of a power supply module, miniaturization of the devices and low cost. The CLASS H is a dynamic power supply framework matched with the audio power amplifier, and the core is to dynamically adjust the power supply voltage of the power amplifier according to the amplitude of an audio signal, and the CLASS AB and CLASS D audio power amplifier adopting the CLASS H dynamic power supply framework has better power supply utilization efficiency compared with the traditional fixed power supply type power amplifier, so that the CLASS AB and CLASS D audio power amplifier becomes a main power amplifier scheme of high-power portable audio equipment. In order to drive the speaker to output higher power at a limited power supply module voltage, a boost converter is typically required to be configured at the front end of an audio power amplifier (power amplifier). The boost converter is used to boost the power module voltage to a higher, relatively constant voltage value (commonly referred to as PVDD, i.e. the power amplifier supply voltage) to power the power amplifier module, thereby ensuring that the power amplifier has sufficient voltage swing to provide instantaneous high power to the load (speaker) when peaks of the audio signal come. In conventional CLASS H audio power amplification systems, the boost converter is typically designed to output a fixed high voltage. In order for the designer to ensure that the system outputs undistorted under any conditions (e.g., maximum volume, maximum peak audio signal), the PVDD voltage must be set at a level high enough to cover the maximum output power requirement. However, the actual audio signal has a very large dynamic range and a very low duty cycle. For music or speech signals, the time in which the transient peak occurs is very short, and most of the time the output amplitude of the audio signal is well below the fixed PVDD value. This means that the power amplifier module has a supply voltage (PVDD) that is much higher than the actually required output voltage during most of its operating time. The working mode of high voltage low power consumption can cause two main problems that firstly, the boost converter needs to continuously work in a high voltage output state, unnecessary energy conversion is carried out even when no large signal is required, larger switching loss and conduction loss are generated, and secondly, in a power amplifier stage, the voltage drop of an output pipe of the power amplifier is increased due to the excessively high power supply voltage, so that heat generation and energy waste are further aggravated. For portable devices that rely on a power module to supply power, this sustained, unnecessary energy loss can significantly shorten the endurance of the device, reducing the user experience. In order to solve the efficiency problem caused by the fixed high-voltage power supply, some improvements are presented in the prior art. For example, one common control scheme is to put the boost circuit in a "pass-through" mode in a default state, i.e., PVDD voltage is equal to the power module voltage. The system monitors the amplitude of the audio signal in real time by the controller. When the controller detects that the amplitude of the audio signal is about to exceed the current power supply module voltage, a boosting indication signal is triggered, the signal is locked and kept once triggered, the boosting circuit is forced to start working, and the output voltage is directly raised to a PVDD value required by the preset maximum power. However, this solution has the disadvantage of "hysteresis" and "discontinuity" of its control. Once the boost is triggered, the PVDD will jump directly from the power supply module voltage to the highest set voltage, even if the audio signal amplitude falls back for a short period of time, the PVDD remains at the highest value until the next detection period or system reset. The two-stage control of non-rising and falling (in practice, locking type single boosting) does not really realize the dynamic following of the power supply voltage to the audio signal, and still has the problem of energy waste caused by overhigh PVDD voltage when the amplitude of the audio signal is smaller, and cannot realize the fine energy-saving control. In summary, the boost power supply control scheme of the existing CLASS-H