Power supply method, power supply circuit, audio device, chip and electronic equipment

Abstract

The invention relates to the technical field of audio power amplifiers, and discloses a power supply method and circuit, an audio device, a chip and electronic equipment. The method comprises the following steps: generating a first mark signal according to an audio input signal, a step-down threshold and a corresponding step-down hysteresis threshold; determining whether voltage reduction is indicated or not according to the first mark signal, and if the first mark signal indicates voltage reduction, generating a voltage reduction control signal; according to the step-down control signal, a step-down mode is started, a step-down charge pump is used, the power supply voltage of a power output stage circuit in the audio power amplifier is reduced from the first power supply voltage to a second power supply voltage, the second power supply voltage is output to supply power to the power output stage circuit, and the second power supply voltage is lower than the power supply voltage of the audio power amplifier.

Description

Technical Field

[0001] The present application relates to the technical field of audio power amplifiers, and in particular to a power supply method, a power supply circuit, an audio device, a chip and an electronic device. Background Art

[0002] As portable devices such as smartphones have higher and higher requirements for static and dynamic power consumption, audio amplifiers are also required to have lower static and dynamic power consumption. Audio amplifiers include power output stage circuits, which are responsible for converting the amplified audio signal into sufficient power to drive the speaker to produce sound. The energy distribution of audio signals is mainly concentrated in the mid- and low-frequency parts, and the low-frequency signal has a large amplitude. By providing a higher power supply voltage to the power output stage circuit, the low-frequency signal can be avoided from being compressed, thereby improving the dynamic range of the low-frequency part and optimizing the audio output effect.

[0003] However, when the amplitude of the input audio signal is small and there is no need to improve the dynamic range of the audio signal, if the power supply voltage of the power output stage circuit is high, it will lead to high power loss of the audio amplifier, that is, high power consumption. Summary of the invention

[0004] Embodiments of the present application provide a power supply method, a power supply circuit, an audio device, a chip, and an electronic device.

[0005] In a first aspect, an embodiment of the present application provides a power supply method, the method comprising: generating a first flag signal according to an audio input signal, a voltage reduction threshold and a corresponding voltage reduction hysteresis threshold; determining whether a voltage reduction is indicated according to the first flag signal, and generating a voltage reduction control signal if the first flag signal indicates a voltage reduction; according to the voltage reduction control signal, turning on the voltage reduction mode, using a voltage reduction charge pump, reducing the power supply voltage of a power output stage circuit in an audio power amplifier from a first power supply voltage to a second power supply voltage, and outputting the second power supply voltage to power the power output stage circuit, wherein the second power supply voltage is lower than the power supply voltage of the power supply. The voltage reduction threshold is less than the voltage reduction hysteresis threshold.

[0006] It can be understood that the first power supply voltage is greater than or equal to the power supply voltage of the audio power amplifier, such as being equal to the power supply voltage. At this time, the power supply circuit can switch the power supply mode of the power output stage circuit from the direct mode to the buck mode to reduce the power supply voltage of the power output stage circuit from the first power supply voltage to the second power supply voltage. In this way, the power consumption of the power output stage circuit can be reduced by reducing the power supply voltage of the power output stage circuit, thereby reducing the overall power consumption of the device.

[0007] In a possible implementation, the step-down charge pump is a 1 / 2 charge pump, and the difference between the second power supply voltage and 1 / 2 times the power supply voltage is less than or equal to a preset difference. In this case, the step-down charge pump is a 1 / 2 charge pump.

[0008] In a possible implementation, the method further includes: if the first flag signal indicates no voltage reduction, starting the pass-through mode, and outputting the power supply voltage to supply power to the power output stage circuit. In this case, the power supply voltage does not need to be reduced.

[0009] In one possible implementation, if the differential signal of the audio input signal is less than or equal to the voltage reduction threshold, the first flag signal is used to indicate voltage reduction; if the differential signal of the audio input signal is greater than or equal to the voltage reduction hysteresis threshold corresponding to the voltage reduction threshold, the first flag signal is used to indicate no voltage reduction.

[0010] In a possible implementation, the voltage drop threshold is related to the power supply voltage, wherein the voltage drop threshold and the corresponding voltage drop hysteresis threshold increase as the power supply voltage increases, and the voltage drop threshold and the corresponding voltage drop hysteresis threshold decrease as the power supply voltage decreases.

[0011] In one possible implementation, the power supply voltage is within a first voltage range, and the voltage drop threshold and the voltage drop hysteresis threshold correspond to the first voltage range; wherein the first voltage range is a preset voltage range among multiple preset voltage ranges, each voltage range corresponds to a voltage drop threshold and a voltage drop hysteresis threshold, and the preset voltage range with a smaller voltage minimum value has smaller corresponding voltage drop threshold and voltage drop hysteresis threshold.

[0012] In one possible implementation, reducing the power supply voltage of a power output stage circuit in an audio power amplifier from a first power supply voltage to a second power supply voltage includes: using a step-down charge pump to reduce the power supply voltage of the power output stage circuit from the first power supply voltage to the second power supply voltage.

[0013] In a second aspect, an embodiment of the present application provides a power supply circuit, which includes: a voltage detection circuit, connected to a power supply of the power supply circuit, and used to generate a first flag signal according to an audio input signal of the audio power amplifier, a voltage reduction threshold and a corresponding voltage reduction hysteresis threshold, wherein the first flag signal is used to indicate whether to reduce the voltage; a control circuit, connected to the voltage detection circuit, and used to determine whether to indicate a voltage reduction according to the first flag signal, and generate a voltage reduction control signal if the first flag signal indicates a voltage reduction; an adaptive voltage reduction circuit, connected to the control circuit, and used to use a voltage reduction charge pump to reduce the power supply voltage of a power output stage circuit in the audio power amplifier from a first power supply voltage to a second power supply voltage according to the voltage reduction control signal, and output the second power supply voltage to power the power output stage circuit, wherein the second supply voltage is lower than the power supply voltage of the power supply.

[0014] In a possible implementation, the voltage detection circuit includes: the voltage detection circuit includes: a voltage generating circuit and a signal detection circuit, the signal detection circuit includes a first comparator, a second comparator and a logic circuit, wherein one end of the voltage generating circuit is connected to a power supply, the other end of the voltage generating circuit is connected to a negative input end of the first comparator and a negative input end of the second comparator, and the output end of the first comparator and the output end of the second comparator are connected to the logic circuit; the voltage generating circuit is used to generate a voltage drop threshold and a corresponding voltage drop hysteresis threshold according to the power supply voltage; the first comparator is used to generate a first comparison value according to a first differential signal of an audio input signal and a voltage drop threshold or a voltage drop hysteresis threshold; the second comparator is used to generate a second comparison value according to a second differential signal of the audio input signal and a voltage drop threshold or a voltage drop hysteresis threshold; the logic circuit is used to compare the first comparison value with the first comparison value to generate a first flag signal.

[0015] In one possible implementation, the positive input of the first comparator and the positive input of the second comparator are respectively connected to the two inputs of the first-stage amplifier of the audio power amplifier, or the positive input of the first comparator and the positive input of the second comparator are respectively connected to the two outputs of the first-stage amplifier of the audio power amplifier, or the positive input of the first comparator and the positive input of the second comparator are respectively connected to the two inputs of the second-stage amplifier of the audio power amplifier, or the positive input of the first comparator and the positive input of the second comparator are respectively connected to the two outputs of the second-stage amplifier of the audio power amplifier.

[0016] In one possible implementation, the voltage generating circuit includes a first resistor and a second resistor, one end of the first resistor is connected to a power supply, the other end of the first resistor is connected to a voltage detection circuit and one end of the second resistor, the other end of the second resistor is grounded, and the voltage circuit is used to divide the power supply voltage to obtain a voltage drop threshold or a voltage drop hysteresis threshold; wherein the resistance value of the first resistor is (1-k)*R, the resistance value of the second resistor is k*R, and the voltage drop threshold is k times the power supply voltage.

[0017] In a possible implementation, the voltage generating circuit includes: a first resistor, a second resistor, an operational amplifier circuit, a first transistor, a second transistor, a third transistor, a third resistor, a fourth resistor and a fifth resistor, one end of the first resistor is connected to a power supply, the other end of the first resistor is connected to one end of the second resistor and a positive input end of the operational amplifier circuit, the negative input end of the operational amplifier circuit is connected to one end of the third resistor and a source of the first transistor, the output end of the operational amplifier circuit is connected to the gate of the first transistor, the drain of the first transistor is connected to the gate and source of the second transistor and the gate of the third transistor, the drain of the second transistor is connected to the power supply, the gate of the second transistor is connected to the gate of the third transistor, the drain of the third transistor is connected to the power supply, the source of the third transistor is connected to one end of the fourth resistor, the other end of the fourth resistor is connected to one end of the fifth resistor, the other end of the second resistor, the other end of the third resistor and the other end of the fifth resistor are grounded, and the voltage generating circuit is used to perform voltage division and voltage stabilization processing on the power supply voltage to obtain a voltage reduction threshold or a voltage reduction hysteresis threshold.

[0018] In a possible implementation, the adaptive buck circuit includes: a charge pump power tube circuit, a flying capacitor, an output voltage detection circuit, and an undervoltage protection circuit, wherein the charge pump power tube circuit is connected in parallel with the flying capacitor, a first input end of the charge pump power circuit is connected to a power supply, a second input end of the charge pump power circuit is connected to an output end of a control circuit, an output end of the charge pump power circuit is connected to one end of an output voltage detection circuit, another end of the output voltage detection circuit is connected to one end of an undervoltage protection circuit, and another end of the undervoltage protection circuit is connected to the control circuit; the charge pump power tube circuit is used to regulate the power supply voltage according to a voltage regulation control signal to output a power supply voltage, wherein the voltage regulation control signal is used to control the switching state of a power tube switch in the charge pump power tube circuit to control the charging and / or discharging of the flying capacitor; an output voltage detection module is used to detect the power supply voltage output by the charge pump power tube circuit to obtain a detection voltage; the undervoltage protection circuit is used to compare the detection voltage with a reference voltage to obtain a clamping signal, and the clamping signal is used to clamp the power supply voltage output by the charge pump power tube circuit; and the control circuit is used to generate a voltage regulation control signal according to the clamping signal and a first flag signal.

[0019] In a possible implementation, the charge pump power tube circuit includes a first switch, a second switch, a third switch and a fourth switch, one end of the first switch is connected to the upper plate of the input capacitor and the power supply, the other end of the first switch is connected to one end of the fourth switch and the upper plate of the flying capacitor; one end of the second switch is connected to the lower plate of the flying capacitor and one end of the third switch, the other end of the second switch is connected to the other end of the fourth switch connected to the upper plate of the output capacitor and the power output stage circuit; the other end of the third switch is connected to the lower plate of the input capacitor and grounded; the other end of the fourth switch is connected to the upper plate of the output capacitor, and the lower plate of the output capacitor is grounded.

[0020] In a possible implementation, the adaptive buck circuit is a 1 / 2 charge pump, the voltage regulation control signal is a buck control signal, and the clamp signal is used to clamp the supply voltage output by the charge pump power tube circuit to a voltage between 1 / 2 times the power supply voltage and the power supply voltage; the charge pump power tube circuit is used to control the first switch and the second switch to be turned on, and the third switch and the fourth switch to be turned off according to the buck control signal, so as to control the charging of the flying capacitor so that the voltage on the flying capacitor is 1 / 2 times the power supply voltage, and to control the first switch and the second switch to be turned off, and the third switch and the fourth switch to be turned on, so as to control the discharge of the flying capacitor so that the supply voltage output by the charge pump power tube circuit is the second supply voltage, and the second supply voltage is 1 / 2 times the power supply voltage.

[0021] In one possible implementation, the voltage regulation control signal is a pass-through control signal, and the clamping signal is used to clamp the supply voltage output by the charge pump power tube circuit to the power supply voltage; the charge pump power tube circuit is used to control the first switch and the fourth switch to be turned on, and the second switch and the third switch to be turned off according to the pass-through control signal, so as to control the supply voltage output by the charge pump power tube circuit to be the power supply voltage.

[0022] In one possible implementation, the second supply voltage is equal to 1 / 2 times the power supply voltage minus the product of the target current and the target impedance, wherein the target current is the current flowing through the charge pump power tube circuit, and the target impedance is the sum of the impedance of the fourth switch and the impedance of the third switch.

[0023] In a third aspect, an embodiment of the present application provides an audio device, the audio device comprising an audio power amplifier and a power supply circuit, the audio power amplifier comprising a power output stage circuit, the power supply circuit comprising: a voltage detection circuit, connected to a power supply of the power supply circuit, and generating a first flag signal according to an audio input signal of the audio power amplifier, a voltage reduction threshold and a corresponding voltage reduction hysteresis threshold, wherein the first flag signal is used to indicate whether to reduce the voltage; a control circuit, connected to the voltage detection circuit, and used to generate a voltage reduction control signal if the first flag signal indicates a voltage reduction; an adaptive voltage reduction circuit, connected to the control circuit, used to respond to the voltage reduction control signal, use a voltage reduction charge pump to reduce the power supply voltage of the power output stage circuit in the audio power amplifier from the first power supply voltage to the second power supply voltage, and output the second power supply voltage to power the power output stage circuit, wherein the second power supply voltage is lower than the power supply voltage of the power supply of the power supply circuit.

[0024] In a possible implementation, the step-down charge pump is a 1 / 2 charge pump, and the difference between the second power supply voltage and 1 / 2 times the power supply voltage is less than or equal to a preset difference.

[0025] In one possible implementation, the power output stage circuit includes a first H-bridge power tube circuit, a second H-bridge power tube circuit, and a switch circuit, wherein the power output stage circuit is used to detect that the amplitude of the audio input signal is greater than a comparison threshold, control the switch circuit to be turned on, control the first H-bridge power tube circuit to input the audio input signal, and control the power supply voltage of the first H-bridge power tube circuit to be the first power supply voltage; the power output stage circuit is used to detect that the amplitude of the audio input signal is less than or equal to the comparison threshold, control the switch circuit to be turned off, control the second H-bridge power tube circuit to input the audio input signal, and control the power supply voltage of the second H-bridge power tube circuit to be the second power supply voltage.

[0026] In a possible implementation, the first H-bridge power tube circuit and the second H-bridge power tube circuit each include four transistors; or, the first H-bridge power tube circuit includes four transistors, and the second H-bridge power tube circuit includes two transistors.

[0027] In one possible implementation, the power output stage includes a third H-bridge power tube circuit, wherein the power output stage circuit is used to detect that the amplitude of the audio input signal is less than or equal to a comparison threshold, control the third H-bridge power tube circuit to input the audio input signal, and control the power supply voltage of the third H-bridge power tube circuit to be the second power supply voltage.

[0028] In a fourth aspect, an embodiment of the present application provides a chip, the chip including a circuit, and the circuit is used to implement the audio device in the third aspect and any possible implementation method thereof.

[0029] In a fifth aspect, an embodiment of the present application provides an electronic device, which includes a chip and a speaker as described in the fourth aspect above, and the chip is used to drive the speaker to produce sound.

[0030] It can be understood that the beneficial effects of the second to fifth aspects mentioned above can be referred to the description of the first aspect and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1A A boost power supply provided in an embodiment of the present application provides a scenario in which a power supply voltage is provided to a power output stage circuit;

[0032] Figure 1B A scenario in which a high-voltage power supply provides a power supply voltage for a power output stage circuit provided in an embodiment of the present application;

[0033] Figure 2 A schematic diagram of a power supply method according to an embodiment of the present invention;

[0034] Figure 3 A schematic diagram of a power supply method according to an embodiment of the present invention;

[0035] Figure 4 A schematic diagram of a power supply circuit 10 provided in an embodiment of the present application;

[0036] Figure 5 A schematic diagram of the structure of an audio device 100 provided in an embodiment of the present application;

[0037] Figure 6 A schematic diagram of the related structures of a voltage generating circuit 111 and a signal detecting circuit 112 provided in an embodiment of the present application;

[0038] Figure 7 A schematic diagram of a setting rule for a voltage reduction threshold VTH provided in an embodiment of the present application;

[0039] Fig. 8A A schematic diagram of the structure of a voltage generating circuit 111 provided in an embodiment of the present application;

[0040] Figure 8B A schematic diagram of the structure of a voltage generating circuit 111 provided in an embodiment of the present application;

[0041] Fig. 9 A schematic diagram of the structure of an adaptive buck circuit provided in an embodiment of the present application;

[0042] Fig. 10A A schematic diagram of the structure of a charge pump power tube circuit 131 provided in an embodiment of the present application;

[0043] Fig. 10BA schematic diagram of the structure of a charge pump power tube circuit 131 provided in an embodiment of the present application;

[0044] Fig.11 A schematic diagram of the structure of a power output stage circuit provided in an embodiment of the present application;

[0045] Fig.12 A schematic diagram of the structure of a rate output stage circuit provided in an embodiment of the present application;

[0046] Fig.13 A schematic diagram of the structure of a rate output stage circuit provided in an embodiment of the present application;

[0047] Fig.14 According to some embodiments of the present application, a block diagram of a system on chip (SoC) is shown. DETAILED DESCRIPTION

[0048] Illustrative embodiments of the present application include, but are not limited to, power supply methods and circuits, audio devices, chips, and electronic devices.

[0049] First, the terms provided in the embodiments of the present application are introduced.

[0050] 1. Static power consumption, also known as leakage power consumption or standby power consumption, refers to the power consumed by the audio amplifier due to the static current of the internal circuit when there is no signal input or output. Static power consumption is usually caused by the leakage current of the device, bias current and other static current sources in the circuit.

[0051] 2. Dynamic power consumption refers to the power consumed by the audio amplifier when processing audio signals due to the dynamic changes of the signal (such as amplitude, frequency, etc.). The size of dynamic power consumption is related to factors such as the characteristics of the audio signal, the output power of the amplifier, and efficiency.

[0052] 3. A charge pump, also known as a switched capacitor voltage converter, is an electronic device that uses the properties of capacitance to convert voltage. For example, a 1 / 2 charge pump, also known as a step-down charge pump, can reduce the input voltage to half of the original voltage.

[0053] Reference Figure 1AAs shown, it is a scenario in the related art that a boost power supply is used to provide a power supply voltage for a power output stage circuit. In this scenario, the boost power supply can be adjusted to be in a pass-through mode or a boost mode according to the amplitude of the audio signal. When the amplitude of the input audio signal is small and does not reach the set boost threshold, the boost power supply is adjusted to be in the pass-through mode, and the power output stage circuit is directly powered by a power supply such as a battery; when the input audio signal increases and reaches or exceeds the boost threshold, the boost power supply is switched from the pass-through mode to the boost mode, and the voltage is boosted to the set voltage value to provide a greater output power for the audio amplifier. However, in the case of an audio signal with a small input amplitude, the power output stage circuit is in the pass-through mode and is directly powered by the power supply. When the output power is small, such as less than 0.28 watts (W), the power consumption is still high.

[0054] Reference Figure 1B As shown, it is a scenario in the related art that a high-voltage power supply is used to provide a power supply voltage for a power output stage circuit. For example, this scenario can be applied to an Internet of Things (IoT) device powered by two or more batteries. At this time, the voltage of the power supply of the audio amplifier is relatively high, such as 8.5V for two batteries or 12.5 for three batteries, which makes the static current of the amplifier relatively high. In addition, when the amplitude of the dynamically input audio signal is small, the output power is small, such as when it is less than 2W, the power consumption of the power output stage current is relatively high.

[0055] As known from the background art, when the amplitude of the input audio signal is small, if the power supply voltage of the power output stage circuit in the audio amplifier is large, the power consumption of the audio amplifier will be large. Figure 1A and Figure 1B In the power supply scenario shown, when the amplitude of the input audio signal is small, the power consumption of the audio power amplifier is large.

[0056] In order to solve the above problems, an embodiment of the present application provides a power supply method, which uses an adaptive voltage reduction method to determine whether voltage reduction is required based on a set voltage reduction threshold and a corresponding voltage reduction hysteresis voltage. If voltage reduction is required, the power supply voltage of the power output stage circuit in the audio power amplifier is reduced. Thus, the power loss of the power output stage circuit is reduced, such as reducing the power consumption when the output power of the power output stage circuit is relatively small.

[0057] In some embodiments, the voltage reduction threshold may change synchronously with the power supply voltage to further reduce power consumption at lower output power, thereby improving the overall efficiency of the audio power amplifier.

[0058] In some embodiments, the execution subject of the power supply method provided in the embodiments of the present application may be a power supply circuit, which may supply power to a driving circuit such as an audio power amplifier or a motor driver. In the following embodiments, the power supply method and the power supply circuit are mainly described by taking the power supply circuit supplying power to the audio power amplifier and driving the speaker to produce sound as an example.

[0059] It can be understood that the present application aims to provide a power supply circuit and a power supply method, which can reduce the power consumption of the audio amplifier, improve the efficiency of small and medium signals, i.e., audio input signals with small amplitudes, when driving the speakers, reduce power loss, and extend the service life of the audio amplifier.

[0060] In some embodiments, the above-mentioned power supply circuit can be applied to wearable devices such as watches or electronic devices such as IoT devices. It can be understood that with the advancement of technology, wearable devices such as watches and IoT devices are developing in the direction of functional integration, diversified interaction, and lightweight form, and the application scenarios are constantly expanding. For wearable devices with limited space, the battery capacity is lower, usually around 50mAH to 100mAH, and a low-power design is required to ensure that the device has a long battery life to meet the needs of users for long-term use. Then, in the present application, in a wearable device or IoT device, the power supply voltage of the power output stage circuit of the audio amplifier can be reduced by an adaptive buck method to reduce the power consumption of the audio amplifier.

[0061] As an example, the electronic device in the present application is not limited to low-power IoT devices, but can also be an open wearable stereo headset (OWS), a true wireless stereo headset (TWS), etc.

[0062] like Figure 2 As shown, a power supply method provided in an embodiment of the present application is provided. The execution subject of the power supply method may be a power supply circuit connected to an audio power amplifier. The method comprises the following steps:

[0063] S201: Generate a first flag signal according to an audio input signal of an audio power amplifier, a voltage reduction threshold and a corresponding voltage reduction hysteresis threshold, wherein the first flag signal is used to indicate whether to reduce the voltage, and the voltage reduction threshold is related to the power supply voltage of the audio power amplifier.

[0064] In some embodiments, if the voltage value of the audio input signal is less than or equal to the voltage reduction threshold, the first flag signal is used to indicate voltage reduction, and the first flag signal can be called a voltage reduction flag signal. If the voltage value of the audio input signal is greater than or equal to the voltage reduction hysteresis threshold corresponding to the voltage reduction threshold, the first flag signal is used to indicate no voltage reduction.

[0065] It can be understood that there is a mapping relationship between the power supply voltage and the output power of the power output stage circuit. For example, the output power can be obtained by performing gain conversion on the power supply voltage. At this time, the output power is equal to the power supply voltage multiplied by the set gain value. Among them, the specific value of the gain value is not limited in this application and can be set according to actual needs.

[0066] In some embodiments, the voltage drop threshold and the corresponding voltage drop hysteresis threshold increase as the power supply voltage increases, and the voltage drop threshold and the corresponding voltage drop hysteresis threshold decrease as the power supply voltage decreases.

[0067] In some embodiments, the power supply voltage is within a first voltage range, and the voltage drop threshold and the voltage drop hysteresis threshold correspond to the first voltage range. The first voltage range is a preset voltage range among a plurality of preset voltage ranges, each voltage range corresponds to a voltage drop threshold and a voltage drop hysteresis threshold, and the preset voltage range with a smaller voltage minimum value corresponds to a smaller voltage drop threshold and voltage drop hysteresis threshold.

[0068] As an example, the power supply voltage of the audio power amplifier is the battery voltage (VBAT), and the buck threshold changes synchronously with the VBAT supply voltage, such as when VBAT is high, the buck threshold (denoted as VTH) is high, and when VBAT is low, VTH is low. Similarly, the buck hysteresis threshold (denoted as VTH_HYS) corresponding to the buck threshold is determined in the same way as VTH, thereby further saving power consumption. For example, within the voltage range of the VBAT voltage, the value of VTH can be a fixed value, which is determined according to the minimum VBAT value within the voltage range.

[0069] S202: Determine whether a voltage reduction is indicated according to the first flag signal.

[0070] When the first flag signal indicates a voltage reduction, it means that the output power of the power output stage circuit is required to be relatively small, such as less than 2W.

[0071] S203: If the first flag signal indicates a voltage reduction, a voltage reduction control signal is generated, and according to the voltage reduction control signal, the voltage reduction mode is turned on, and a voltage reduction charge pump is used to reduce the power supply voltage of the power output stage circuit in the audio power amplifier from the first power supply voltage to the second power supply voltage, and the second power supply voltage is output to power the power output stage circuit, wherein the second power supply voltage is lower than the power supply voltage of the power supply.

[0072] In some embodiments, the second power supply voltage is half of the first power supply voltage, and the charge pump is a 1 / 2 charge pump. In addition, the first power supply voltage can be a power supply voltage or a voltage lower than the power supply voltage. In the following embodiments, the first power supply voltage is taken as the power supply voltage for example.

[0073] In some embodiments, the difference between the second supply voltage and 1 / 2 times the power supply voltage is less than or equal to a preset difference, such as the preset difference may be a smaller value, such as 0. For example, the second supply voltage may be 1 / 2 times the power supply voltage, and the preset difference is 0.

[0074] In some embodiments, the first power supply voltage is greater than or equal to the power supply voltage of the power supply, such as being equal to the power supply voltage. At this time, the power supply circuit can switch the power supply mode of the power output stage circuit from the direct mode to the buck mode to reduce the power supply voltage of the power output stage circuit from the first power supply voltage to the second power supply voltage. In this way, the power consumption of the power output stage circuit can be reduced by reducing the power supply voltage of the power output stage circuit, thereby reducing the overall power consumption of the device.

[0075] In some embodiments, reference Figure 3 As shown, the power supply method provided by the present application further includes the following step S204, as shown in Figure 2 The illustrated S202 further includes the following step S204:

[0076] S204: If the first flag signal indicates that the voltage should not be reduced, a through control signal is generated, and a through mode is started according to the through control signal, and the output power supply voltage is used to supply power to the power output stage circuit.

[0077] In some embodiments, when the voltage value of the audio input signal is greater than or equal to the buck hysteresis threshold corresponding to the buck threshold, the first flag signal indicates no bucking, and a pass-through control signal can be generated to start the pass-through mode, that is, the power supply mode of the power output stage circuit is switched from the buck mode to the pass-through mode, so as to control the power supply voltage of the power output stage circuit to be the power supply voltage. At this time, the output power of the power output stage circuit is relatively large, such as greater than 2W.

[0078] In some embodiments, when the power supply mode is switched from the buck mode to the pass-through mode, the pass-through mode is turned on after a preset counting time, and the buck mode is maintained within the preset counting time, thereby ensuring smooth switching of the power supply voltage.

[0079] Furthermore, the power supply circuit provided in the embodiment of the present application is introduced.

[0080] Reference Figure 4As shown, a power supply circuit 10 provided in an embodiment of the present application is connected to a power supply and an audio power amplifier. Specifically, the power supply circuit 10 includes: a voltage detection circuit 11, a control circuit 12 and an adaptive buck circuit 13. The voltage detection circuit 11 is connected to the power supply (VBAT) of the power supply circuit 10, and is used to generate a first flag signal according to the audio input signal of the audio power amplifier, the buck threshold and the corresponding buck hysteresis threshold; the control circuit 12 is connected to the voltage detection circuit 11, and is used to determine whether to indicate a buck according to the first flag signal, and if the first flag signal indicates a buck, a buck control signal is generated; the adaptive buck circuit 13 is connected to the control circuit 12, and is used to respond to the buck control signal, use a buck charge pump, reduce the power supply voltage of the power output stage circuit in the audio power amplifier from the first power supply voltage to the second power supply voltage, and output the second power supply voltage to power the power output stage circuit, wherein the second power supply voltage is lower than the power supply voltage.

[0081] In addition, if Figure 4 As shown, the power output stage circuit of the audio power amplifier can be connected to the adaptive buck circuit 13 and the speaker, so that the adaptive buck circuit 13 outputs a power supply voltage such as the second power supply voltage to the power output stage circuit, and controls the audio power amplifier to drive the speaker to play the audio input signal based on the second power supply voltage. In addition, the audio power amplifier can be connected to the power supply VABT and the signal input device (IN+ and IN-) for inputting the audio input signal (IN+ and IN-) Figure 4 not shown).

[0082] In some embodiments, in an IoT device, the power supply may be one or more batteries, for example, the power supply voltage of two batteries is 8.5V, and the power supply voltage of three batteries is 12.5V.

[0083] Reference Figure 5 , which is a schematic diagram of a driving scenario of an audio device 100. The scenario includes an audio device 100, and the audio device 100 includes a power supply circuit 10 and an audio power amplifier 20.

[0084] The audio power amplifier 20 is used to amplify the audio input signal to drive the speaker to produce sound.

[0085] like Figure 5 As shown, the audio power amplifier 20 is used to drive the speaker to generate sound through the audio input signal. The audio power amplifier 20 includes: a preamplifier, an integrator, a triangle wave generator, and two comparator power output stage circuits.

[0086] In some embodiments, the audio power amplifier 20 may be a class D power amplifier or a class AB power amplifier.

[0087] In some embodiments, the preamplifier inputs the differential signal VOP0 and the differential signal VON0 of the audio input signal to the positive input terminal (IN+) and the negative input terminal (IN-) respectively in a differential manner, performs preliminary amplification and preprocessing on the audio input signal such as volume control, tone adjustment, etc., and outputs the differential signal VOP1 (positive output voltage) and the differential signal VON1 (negative output voltage).

[0088] The integrator is used to input the differential signal VOP1 and the differential signal VON1, perform processing such as noise shaping by using an integral operation, and output a differential signal VOP2 and a differential signal VON2.

[0089] The triangle wave generator is used to generate a triangle wave signal.

[0090] Both comparators in the audio power amplifier 20 are pulse width modulation (PWM) comparators, which are used to compare the amplified audio signal with the triangular wave signal to generate a PWM signal, and the duty cycle of the PWM signal is proportional to the amplitude of the audio signal. For example, the audio power amplifier 20 can pre-set a comparison threshold, such as the comparison threshold corresponding to a preset duty cycle. The audio power amplifier 20 determines the amplitude of the audio input signal and the size of the comparison threshold by judging the size of the duty cycle of the PWM signal of the differential signal VOP2 and the differential signal VON2 and the preset duty cycle. It can be understood that when the amplitude of the audio input signal is greater than the comparison threshold, the audio input signal requires the audio power amplifier to provide a larger output power. When the amplitude of the audio input signal is less than or equal to the comparison threshold, the audio input signal requires the audio power amplifier to provide a smaller output power.

[0091] The power output stage circuit is used to receive the PWM signal from the PWM comparator, and convert the PWM signal into a high-power audio output signal to drive the speaker through the rapid conduction and cutoff of the power tube switch (i.e., switch) in the power output stage circuit.

[0092] In some embodiments, in order to meet the requirements of low-capacity battery or overall system low power consumption of the electronic device in which the audio device is located, it is usually Figure 5 Each module in the circuit is designed with low bias current. Furthermore, in order to reduce the power consumption of the power output stage circuit, the frequency of the triangle wave generator or the modulation frequency of the power amplifier loop such as the preamplifier and the integrator is designed with a lower frequency.

[0093] like Figure 5 As shown, the power supply circuit 10 is used to provide a power supply voltage for the power output stage circuit. In addition, the voltage detection module 11 in the power supply circuit 10 includes a voltage generation module 111 and a signal detection module 112 .

[0094] One end of the voltage generating circuit 111 is connected to the power supply, and the other end of the voltage generating circuit 111 is connected to the signal detection module 112. Specifically, the voltage generating circuit 111 is used to generate a voltage drop threshold VTH and a corresponding voltage drop hysteresis threshold VTH_HYS according to the power supply voltage VBAT, and output the voltage drop threshold VTH and the corresponding voltage drop hysteresis threshold VTH_HYS to the signal detection module 112.

[0095] The first input end of the signal detection module 112 is used to receive a first differential signal, such as a differential signal VOP1 output by a preamplifier in the audio power amplifier 20. The second input end of the signal detection module 112 inputs a second differential signal, such as a differential signal VON1 output by a preamplifier in the audio power amplifier 20, so that the output end of the signal detection module 112 outputs a first flag signal EN_STD.

[0096] In some embodiments, the first flag signal EN_STD is a voltage reduction flag signal indicating voltage reduction, and EN_STD is equal to a first value such as 1; the first flag signal EN_STD is a through flag signal indicating no voltage reduction, and EN_STD is equal to a second value such as 0. It can be understood that the values ​​of the above-mentioned first value and second value can be designed according to the requirements of the actual circuit, and the present application does not make specific limitations. For example, the first value and the second value can also be 0 and 1 respectively.

[0097] In addition, the control circuit 12 is used to generate a voltage regulation control signal MD_CTRL in response to the first flag signal EN_STD output by the signal detection circuit 112. The adaptive buck circuit 13 is used to input the voltage regulation control signal MD_CTRL, and adjust the output power supply voltage PVDD in response to the voltage regulation control signal MD_CTRL, such as reducing the power supply voltage PVDD from the first power supply voltage to the second power supply voltage. For example, the first power supply voltage can be the power supply voltage VBAT, and the second power supply voltage can be 1 / 2 times the power supply voltage VBAT.

[0098] Reference Figure 6 , a schematic diagram of the structure of the voltage generating circuit 111 and the signal detecting circuit 112. Figure 6As shown, the signal detection circuit 112 includes a first comparator COMP1, a second comparator COMP2 and a logic circuit, wherein the first input terminal of the first comparator COMP1 inputs a first differential signal of an audio input signal such as a differential signal VOP1, the second input terminal of the first comparator COMP1 inputs a buck threshold or a buck hysteresis threshold, and the output terminal of the first comparator COMP1 outputs a first comparison value; the first input terminal of the second comparator COMP2 inputs a second differential signal of the audio input signal such as a differential signal VON1, the second input terminal of the second comparator COMP2 inputs a buck threshold or a buck hysteresis threshold, and the output terminal of the second comparator COMP2 outputs a second comparison value; the first input terminal of the logic circuit inputs the first comparison value output by the first comparator COMP1, the second input terminal of the logic circuit inputs the second comparison value output by the second comparator COMP2, and the output terminal of the logic circuit outputs a first flag signal EN_STD.

[0099] It can be understood that the first comparator COMP1 is used to generate a first comparison value according to the first differential signal of the audio input signal, such as the differential signal VOP1, and the voltage drop threshold VTH or the corresponding voltage drop hysteresis threshold VTH_HYS; the second comparator COMP2 is used to generate a second comparison value according to the second differential signal of the audio input signal, such as the differential signal VON1, and the voltage drop threshold VTH or the corresponding voltage drop hysteresis threshold VTH_HYS. It can be understood that the voltage generating circuit is used to generate the voltage drop threshold and the corresponding voltage drop hysteresis threshold according to the power supply voltage; the logic circuit is used to compare the first comparison value with the first comparison value to generate the first flag signal EN_STD.

[0100] In some embodiments, if the differential signal VOP1 / differential signal VON1 is less than the step-down threshold VTH, the comparator output is 0, and the first comparison value output by the first comparator COMP1 and the second comparison value output by the second comparator COMP2 are both 0. Furthermore, when the differential signal VOP1 / differential signal VON1 is less than the step-down threshold VTH, the first identification signal output by the logic circuit control is the step-down flag signal EN_STD, and the step-down flag signal EN_STD is used to indicate that the audio input signal is less than the step-down threshold VTH, so that the adaptive step-down circuit 13 can reduce the output power supply voltage PVDD.

[0101] In some embodiments, a first terminal of the first comparator COMP1 is connected to a first terminal of the audio power amplifier 20 , and a first terminal of the second comparator COMP2 is connected to a second terminal of the audio power amplifier 20 .

[0102] As an example, Figure 5 and Figure 6As shown, the first end and the second end of the audio power amplifier 20 are respectively two output ends of the first stage amplifier (i.e., preamplifier) ​​of the audio power amplifier 20. At this time, the first differential signal and the second differential signal input by the signal detection circuit 112 are respectively the differential signal VOP1 and the differential signal VON1 output by the preamplifier.

[0103] As another example, the first end and the second end of the audio power amplifier 20 are respectively two input ends of the first stage amplifier (i.e., preamplifier) ​​of the audio power amplifier 20. At this time, the first differential signal and the second differential signal input by the signal detection circuit 112 are respectively the differential signal VOP0 and the differential signal VON0 input by the preamplifier.

[0104] As another example, the first end and the second end of the audio power amplifier 20 are respectively two output ends of the second-stage integrator of the audio power amplifier 20 .

[0105] It can be understood that the first differential signal and the second differential signal are the detection results of the signal detection circuit 112 on the signal value of the audio signal path in the audio power amplifier 20, and the sampling position of the signal detection is not limited to the output of the first-stage preamplifier, but can also be the input of the preamplifier, the input of the second-stage integrator, or the input of the second-stage integrator.

[0106] In some embodiments, the voltage reduction threshold VTH set in the present application may be a fixed value, and the specific value may be determined according to actual needs, and is not specifically limited here. For example, within the power supply range of the power supply voltage VBAT, the value of the voltage reduction threshold VTH is a fixed value, and this fixed value may be determined according to the minimum VBAT value.

[0107] In other embodiments, the voltage drop threshold VTH set in the present application may change synchronously with the power supply voltage VBAT. For example, the voltage drop threshold VTH increases when the power supply voltage VBAT increases, and decreases when the power supply voltage VBAT decreases, further saving power consumption.

[0108] exist Figure 6 Based on Figure 7 , the setting rules of the voltage reduction threshold VTH are described. In some embodiments, VTH=VTH=Y(VBAT); VTH_HYS=Y(VBAT)-b. At this time, the voltage generation circuit 111 generates a voltage reduction threshold VTH and a corresponding voltage reduction hysteresis threshold VTH_HYS related to the power supply voltage VBAT. When the signal detection circuit 112 detects that the differential signal is less than the voltage reduction threshold VTH, the logic circuit outputs a corresponding voltage reduction control signal, and the corresponding voltage reduction power threshold Po is related to the power supply voltage VBAT. Figure 7As shown, the voltage thresholds indicated by points a and b refer to the step-down thresholds VTH corresponding to different power supply voltages VBAT (the power supply range of the power supply voltage VBAT is 3V to 5.5V for a single-cell battery, and the power supply range of the VBAT voltage is 6 to 11V for multiple-cell batteries).

[0109] In some embodiments, reference Fig. 8A , is a schematic diagram of a structure of a voltage generating circuit 111, and the voltage generating circuit 111 is a voltage dividing circuit. Fig. 8A As shown, the voltage generating circuit 111 includes a first resistor R1 and a second resistor R2. The first end of the first resistor R1 is input with a power supply voltage VBAT (i.e. Fig. 8A VDD shown), the second end of the first resistor R1 is connected to the first end of the second resistor R2, the first end of the second resistor R2 outputs the step-down threshold VTH (i.e., Vth) or the step-down hysteresis threshold VTH_HYS, and the second end of the second resistor R2 is grounded, wherein the resistance value of the first resistor R1 is (1-k)*R, the resistance value of the second resistor R2 is k*R, and the step-down threshold VTH is k times the power supply voltage VBAT. At this time, R1 and R2 are voltage-dividing resistors. Among them, the values ​​of k and R are not fixed, and can be determined according to actual needs, and this application does not make specific limitations on this. At this time, the voltage generating circuit 111 is used to divide the power supply voltage VBAT to obtain the step-down threshold VTH or the step-down hysteresis threshold VTH_HYS.

[0110] In some embodiments, reference Figure 8B , is a schematic diagram of a structure of a voltage generating circuit 111, wherein the voltage generating circuit 111 includes a voltage dividing circuit 01 and a buffer circuit 02. Figure 8B As shown, the voltage divider circuit 01 includes a first resistor R1 and a second resistor R2. The buffer circuit 02 includes a third resistor R3, an operational amplifier circuit AMP1, a first transistor MN1, a second transistor MP1, a third transistor MP2, a fourth resistor R4 and a fifth resistor R5.

[0111] One end of the first resistor R1 is connected to the power supply to input the power supply voltage VBAT (i.e. Figure 8B The other end of the first resistor R1 is connected to one end of the second resistor R2 and an input end of the operational amplifier circuit AMP1.

[0112] The other end of the second resistor R2 is grounded, the other input end of the operational amplifier circuit AMP1 is connected to one end of the third resistor R3 and the source of the first transistor MN1, and the output end of the operational amplifier circuit AMP1 is connected to the gate of the first transistor MN1; the drain of the first transistor MN1 is connected to the gate and source of the second transistor MP1 and the gate of the third transistor MP2, the drain of the second transistor MP1 is connected to the power supply to input the power supply voltage VBAT, the gate of the second transistor MP1 is connected to the gate of the third transistor MP2, the drain of the third transistor MP2 inputs the power supply voltage VBAT, the source of the third transistor MP2 is connected to one end of the fourth resistor R4, the other end of the fourth resistor R4 is connected to one end of the fifth resistor R5, the other end of the third resistor R3 is grounded (GND), and the other end of the fifth resistor R5 is grounded. At this time, the voltage generating circuit 111 is used to divide and stabilize the power supply voltage VBAT to obtain the step-down threshold VTH or the step-down hysteresis threshold VTH_HYS.

[0113] It can be understood that the voltage drop threshold VTH that changes synchronously with the power supply can be expressed in the form of k times VBAT. Fig. 8A The voltage divider circuit shown can be easily realized, or it can be realized by Figure 8B The method with stronger anti-interference ability shown in the figure obtains the voltage reduction threshold VTH which is k times VBAT.

[0114] Then, when the power supply voltage VBAT is relatively high, the output power of the chip where the audio device 100 is located will also be correspondingly high, and the adaptive voltage reduction threshold VTH at this time will also be high; when the power supply voltage VBAT is relatively low, the output power of the chip will also be correspondingly low, and the adaptive voltage reduction threshold VTH at this time will also be low, thereby obtaining the maximum efficiency benefit, and greatly optimizing the power consumption of the power output stage circuit at medium and low power.

[0115] Reference Fig. 9 , the relevant structure of the adaptive buck circuit provided by the present application is described. Fig. 9 As shown, the adaptive buck circuit 13 includes: a charge pump power tube circuit 131 and a flying capacitor CF, an output voltage detection circuit 132, and an undervoltage protection circuit 133, wherein the charge pump power tube circuit 131 is connected in parallel with the flying capacitor CF.

[0116] The first input terminal of the charge pump power tube circuit 131 inputs the power supply voltage VBAT, and the second input terminal of the charge pump power tube circuit 131 inputs the voltage regulation control signal Vcon (i.e., MD_CTRL) output by the control circuit 12, and the voltage regulation control signal Vcon is used to control the switch state of the power tube switch in the charge pump power tube circuit 131; the output terminal of the charge pump power tube switch circuit 131 outputs the power supply voltage PVDD; the input terminal of the output voltage detection circuit 132 inputs the power supply voltage PVDD, and the output terminal of the output voltage detection circuit 132 outputs the corresponding detection voltage Vuvp; the first input terminal of the undervoltage protection circuit 133 inputs the detection voltage Vuvp, the second input terminal of the undervoltage protection circuit 133 inputs the reference voltage Vref, and the output terminal of the undervoltage protection circuit 133 outputs the clamping signal UVP, and the clamping signal UVP is used to clamp the power supply voltage output by the charge pump power tube circuit 131. For example, the above-mentioned detection voltage Vuvp is a ratio value of the power supply voltage PVDD, that is, the power supply voltage PVDD and the detection voltage Vuvp have a preset ratio, and the preset ratio can be determined according to actual needs, and is not specifically limited here.

[0117] In addition, the first input terminal of the control circuit 12 inputs the first flag signal EN_STD output by the signal detection circuit 112, the second input terminal of the control circuit 12 inputs the clock signal OSC, the third input terminal of the control circuit 12 inputs the clamping signal UVP output by the undervoltage protection circuit 133, and the fourth input terminal of the control circuit 12 inputs the voltage regulation control signal Vcon (i.e., MD_CTRL, such as a step-down control signal) output by the signal detection module.

[0118] It can be understood that one input end of the charge pump power circuit 131 is connected to the power supply, the other input end of the charge pump power circuit 131 is connected to the output end of the control circuit 12, the output end of the charge pump power circuit 131 is connected to one end of the output voltage detection circuit 132, the other end of the output voltage detection circuit 132 is connected to one end of the undervoltage protection circuit 133, and the other end of the undervoltage protection circuit 133 is connected to the control circuit. In addition, the charge pump power tube circuit 131 is used to regulate the power supply voltage VBAT according to the voltage regulation control signal to output the power supply voltage PVDD, wherein the voltage regulation control signal is used to control the switching state of the power tube switch in the charge pump power tube circuit 131 to control the charging and / or discharging of the flying capacitor CF. The output voltage detection module 132 is used to detect the power supply voltage output by the charge pump power tube circuit 131 to obtain the detection voltage Vuvp. The undervoltage protection circuit 133 is used to compare the detection voltage Vuvp with the reference voltage Vref to obtain the clamping signal UVP, and the clamping signal UVP is used to clamp the power supply voltage PVDD output by the charge pump power tube circuit 131. The control circuit 12 is used to generate a voltage regulation control signal Vcon according to the clamp signal UVP and the first flag signal EN_STD.

[0119] Reference Fig. 10A or Fig. 10B , is a schematic diagram of the structure of the charge pump power tube circuit 131. Specifically, the charge pump power tube circuit 131 includes a first switch S1, a second switch S2, a third switch S3 and a fourth switch S4, one end of the first switch S1 is connected to the power supply and the upper plate of the input capacitor CIN, and the other end of the first switch S1 is connected to one end of the fourth switch S4 and the upper plate CP of the flying capacitor CF; one end of the second switch S2 is connected to the lower plate CN of the flying capacitor CF and the other end of the third switch S3, and the other end of the second switch S2 is connected to the other end of the fourth switch S4, the upper plate of the output capacitor COUT and the power output stage circuit; one end of the third switch S3 is connected to the lower plate of the input capacitor CIN and grounded; the other end of the fourth switch S4 is connected to the upper plate CP of the flying capacitor CF, and the lower plate of the output capacitor COUT is grounded. Among them, the flying capacitor CF can be a flying capacitor.

[0120] Among them, the first switch S1, the second switch S2, the third switch S3 and the fourth switch S4 are all power tubes, that is, power switch tubes.

[0121] In some embodiments, the voltage regulation control signal Vcon is a step-down control signal, and the clamping signal UVP is used to clamp the supply voltage output by the charge pump power tube circuit 131 to a voltage between 1 / 2 times the power supply voltage VBAT and the power supply voltage VBAT.

[0122] like Fig. 10AAs shown, when the power tube in the charge pump power tube circuit 131 is in the charging phase, the charge pump power tube circuit 131 responds to the step-down control signal, controls the first switch S1 and the second switch S2 to be turned on, and controls the third switch S3 and the fourth switch S4 to be turned off, so as to control the charging of the flying capacitor CF, so that the voltage on the flying capacitor CF is 1 / 2 times the power supply voltage VBAT.

[0123] like Fig. 10B As shown, when the power tube in the charge pump power tube circuit 131 is in the discharge phase, the first switch S1 and the second switch S2 are controlled to be turned off, and the third switch S3 and the fourth switch S4 are controlled to be turned on to control the flying capacitor CF to discharge, so that the power supply voltage PVDD output by the charge pump power tube circuit 131 is the second power supply voltage, and the second power supply voltage is 1 / 2 times the power supply voltage VBAT.

[0124] In some embodiments, the second power supply voltage is equal to 1 / 2 times the power supply voltage VBAT minus the product of the target current and the target impedance, wherein the target current is the current flowing through the charge pump power tube circuit 131, and the target impedance is the sum of the impedance of the fourth switch S4 and the impedance of the third switch S3. Fig. 10B As shown, the target current is the discharge current Iout flowing through the third switch S3 and the fourth switch S4.

[0125] In other embodiments, Fig. 10A As shown, the target current is the charging current Iout flowing through the first switch S1 and the second switch S2. At this time, the target impedance may be the sum of the impedance of the first switch S1 and the impedance of the second switch S2.

[0126] In some embodiments, the output voltage of the charge pump power tube circuit 131, namely the supply voltage PVDD and the equivalent internal impedance are derived, considering that the on-resistance of each power tube is equal to Rdson, and ignoring the capacitance reactance, then the supply voltage PVDD = 1 / 2*VBAT - Iout*2*Rdson.

[0127] The equivalent internal impedance of the charge pump power tube circuit 131 is: Rcp0.5x=2*Rdson. It can be understood that the equivalent internal impedance Rcp0.5x is relatively small, and the efficiency of the 1 / 2 times step-down charge pump can reach more than 98%.

[0128] In other embodiments, the voltage regulation control signal is a through control signal, and the clamp signal is used to clamp the power supply voltage output by the charge pump power tube circuit 131 to the power supply voltage VBAT. Then, in response to the through control signal, the charge pump power tube circuit 131 controls the first switch S1 and the fourth switch S4 to be turned on, and the second switch S2 and the third switch S3 to be turned off, and controls the power supply voltage PVDD output by the charge pump power tube circuit 131 to be the power supply voltage VBAT. Similarly, the power supply voltage PVDD actually output by the charge pump power tube circuit 131 = VBAT-Iout*2*Rdson.

[0129] Therefore, the present application can reduce the power supply voltage of the power output stage circuit by half by adopting a 1 / 2 charge pump. At the same time, the voltage reduction threshold changes synchronously with the VBAT battery voltage (such as a single cell or multiple cells), and continues to optimize and reduce the power consumption at small and medium output powers, thereby maximizing the overall efficiency of the chip.

[0130] In some embodiments, the present application may provide a low-power output stage circuit to optimize the power consumption of an audio amplifier at low and medium output powers, and further improve the overall efficiency of the chip in which the audio amplifier is located.

[0131] In some embodiments, Fig.11 and Fig.12 As shown, the power output stage circuit includes a first H-bridge power tube circuit H1 and a second H-bridge power tube circuit H2, and a switch circuit SW, wherein the power output stage circuit detects that the amplitude of the audio input signal is greater than a comparison threshold, controls the switch circuit SW to be turned on, controls the first H-bridge power tube circuit H1 to input the audio input signal (such as the differential signal VOP and the differential signal VON), and controls the power supply voltage PVDD of the first H-bridge power tube circuit to be the first power supply voltage HV Supply; the power output stage circuit detects that the amplitude of the audio input signal is less than or equal to the comparison threshold, controls the switch circuit SW to be turned off, controls the second H-bridge power tube circuit H2 to input the audio input signal (such as the differential signal VOPL and the differential signal VONL), and controls the power supply voltage PVDD of the second H-bridge power tube circuit H2 to be the second power supply voltage LV Supply. At this time, the first H-bridge power tube circuit H1 and the second H-bridge power tube circuit H2 are connected in parallel.

[0132] In some embodiments, Fig.11 and Fig.12It can be seen that the switch circuit SW includes a switch SW0 and a switch SW1. When the switch circuit SW is turned on, that is, when the switch SW0 and the switch SW1 are both turned on, the pass-through mode is entered, and the differential signal VOP and the differential signal VON of the audio input signal are connected to the first H-bridge power tube circuit H1. In addition, when the switch circuit SW is turned off, that is, when the switch SW0 and the switch SW1 are both turned off, the buck mode is entered, and the differential signal VOPL and the differential signal VONL of the audio input signal are connected to the second H-bridge power tube circuit H2. It can be understood that in the embodiment of the present application, the differential signal VOPL and the differential signal VONL refer to the differential signals of the audio input signal with a smaller amplitude, and the differential signal VOP and the differential signal VON refer to the differential signals of the audio input signal with a larger amplitude.

[0133] In some embodiments, Fig.11 As shown, the first H-bridge power tube circuit H1 and the second H-bridge power tube circuit H2 each include four transistors. For example, the first H-bridge power tube circuit H1 includes transistors MP0 and MP1, and transistors MN0 and MN1. Specifically, the drain of transistor MP0 inputs the first supply voltage HV Supply, the gate inputs the drive signal HV_DVP0, the source is connected to one end of the switch SW0, and the source is connected to one end of the speaker. The drain of transistor MP1 inputs the first supply voltage HVSupply, the gate inputs the drive signal HV_DVP1, the source inputs the differential signal VON such as the differential signal VON2 output by the comparator, and the source is connected to one end of the speaker. Similarly, the drain of transistor MN0 is connected to the source of transistor MP0, the gate inputs the drive signal HV_DVN0, the source is connected to one end of the switch SW1, and the source is grounded. The drain of transistor MP1 is the source of transistor MP1, the gate inputs the drive signal HV_DVN1, and the source is grounded.

[0134] In some embodiments, Fig.11 As shown, the second H-bridge power tube circuit H2 includes transistors MLP0 and MLP0, and transistors MLN0 and MLN0. The drain of transistor MN0 inputs the second supply voltage LV Supply, the gate inputs the drive signal HV_DVN0, the source is connected to one end of the switch SW0, and the source is connected to one end of the speaker. The drain of transistor MN1 inputs the second supply voltage LV Supply, the gate inputs the drive signal HV_DVN1, the source inputs the differential signal VON such as the differential signal VON2 output by the comparator, and the source is connected to one end of the speaker. Similarly, the drain of transistor MN0 is connected to the source of transistor MN0, the gate inputs the drive signal HV_DVN0, the source is connected to one end of the switch SW1, and the source is grounded. The drain of transistor MN1 is the source of transistor MN1, the gate inputs the drive signal HV_DVN1, and the source is grounded.

[0135] In some embodiments, Fig.12 As shown, the first H-bridge power tube circuit H1 includes four transistors, and the second H-bridge power tube circuit H2 includes two transistors.

[0136] In some embodiments, Fig.13 As shown, the power output stage includes a third H-bridge power tube circuit, wherein the power output stage circuit detects that the amplitude of the audio input signal is less than or equal to the comparison threshold, controls the third H-bridge power tube circuit to input the audio input signal, and controls the power supply voltage of the third H-bridge power tube circuit to be the second power supply voltage PVDD. The third H-bridge power tube circuit includes four transistors. Fig.11 The second H-bridge power tube circuit H2 shown is similar and will not be described in detail here. At this time, the power output stage circuit is directly powered by the adaptive 1 / 2 charge pump output voltage, realizing power consumption optimization under low and medium power and improving the overall efficiency of the power amplifier.

[0137] The present application uses an adaptive 1 / 2 charge pump to greatly optimize the power consumption of the audio amplifier when the input signal is, especially when the input signal is a small or medium signal, thereby improving the efficiency of the amplifier. At the same time, combined with the input power synchronization technology, different threshold voltages (such as step-down thresholds) are adaptively selected according to different power supplies, thereby further reducing power consumption, optimizing amplifier efficiency, and extending the standby time and working time of the audio amplifier or wearable device under small-capacity battery conditions.

[0138] In some embodiments, the present application provides a chip including the above-mentioned audio device 100 .

[0139] In some embodiments, the present application provides an electronic device comprising the above-mentioned chip.

[0140] In a possible implementation, an embodiment of the present application provides a chip, including a circuit, and the circuit is used to execute the power supply method mentioned above.

[0141] In a possible implementation, an embodiment of the present application provides an electronic device, including a chip and a speaker, wherein the chip is used for the speaker to produce sound.

[0142] According to an embodiment of the present application, Fig.14 FIG. 1 shows a block diagram of a system on chip (SoC) 1500 (i.e., a chip). Fig.14 In the FIG, similar components have the same reference numerals. In addition, the dashed boxes are optional features of more advanced SoCs. Fig.14In the embodiment, SoC 1500 includes: an interconnect unit 1550, which is coupled to an application processor 1510; a system agent unit 1570; a bus controller unit 1580; an integrated memory controller unit 1540; a group or one or more coprocessors 1520, which may include integrated graphics logic, an image processor, an audio processor, and a video processor; a static random access memory (SRAM) unit 1530; and a direct memory access (DMA) unit 1560. In one embodiment, the coprocessor 1520 includes a special-purpose processor, such as, for example, a network or communication processor, a compression engine, a GPGPU, a high-throughput MIC processor, or an embedded processor.

[0143] The various embodiments of the mechanism disclosed in the present application can be implemented in hardware, software, firmware or a combination of these implementation methods. The embodiments of the present application can be implemented as a computer program or program code executed on a programmable system, which includes at least one processor, a storage system (including volatile and non-volatile memory and / or storage elements), at least one input device and at least one output device.

[0144] Program code may be applied to input instructions to perform the functions described herein and generate output information. The output information may be applied to one or more output devices in a known manner. For purposes of this application, a processing system includes any system having a processor such as, for example, a digital signal processor (DSP), a microcontroller, an application specific integrated circuit (ASIC), or a microprocessor.

[0145] Program code can be implemented with high-level programming language or object-oriented programming language to communicate with the processing system. When necessary, program code can also be implemented with assembly language or machine language. In fact, the mechanism described in this application is not limited to the scope of any specific programming language. In either case, the language can be a compiled language or an interpreted language.

[0146] In some cases, the disclosed embodiments may be implemented in hardware, firmware, software, or any combination thereof. The disclosed embodiments may also be implemented as instructions carried or stored on one or more temporary or non-temporary machine-readable (e.g., computer-readable) storage media, which may be read and executed by one or more processors. For example, instructions may be distributed over a network or through other computer-readable media. Therefore, machine-readable media may include any mechanism for storing or transmitting information in a machine (e.g., computer) readable form, including but not limited to floppy disks, optical disks, optical disks, read-only memories (CD-ROMs), magneto-optical disks, read-only memories (ROMs), random access memories (RAMs), erasable programmable read-only memories (EPROMs), electrically erasable programmable read-only memories (EEPROMs), magnetic or optical cards, flash memory, or tangible machine-readable memories for transmitting information (e.g., carrier waves, infrared signals, digital signals, etc.) using the Internet in electrical, optical, acoustic, or other forms of propagation signals. Accordingly, machine-readable media include any type of machine-readable media suitable for storing or transmitting electronic instructions or information in a form readable by a machine (eg, a computer).

[0147] In the accompanying drawings, some structural or method features may be shown in a specific arrangement and / or order. However, it should be understood that such a specific arrangement and / or order may not be required. In some embodiments, these features may be arranged in a manner and / or order different from that shown in the illustrative drawings. In addition, the inclusion of structural or method features in a particular figure does not mean that such features are required in all embodiments, and in some embodiments, these features may not be included or may be combined with other features.

[0148] It should be noted that the units / modules mentioned in the various device embodiments of the present application are all logical units / modules. Physically, a logical unit / module can be a physical unit / module, or a part of a physical unit / module, or can be implemented as a combination of multiple physical units / modules. The physical implementation method of these logical units / modules themselves is not the most important. The combination of functions implemented by these logical units / modules is the key to solving the technical problems proposed by the present application. In addition, in order to highlight the innovative part of the present application, the above-mentioned device embodiments of the present application do not introduce units / modules that are not closely related to solving the technical problems proposed by the present application, which does not mean that there are no other units / modules in the above-mentioned device embodiments.

[0149] It should be noted that in the examples and description of this patent, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "including one" do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0150] Although the present application has been illustrated and described with reference to certain preferred embodiments thereof, it will be apparent to those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present application.

Claims

1. A power supply method, characterized in that: The method comprises: Generate a first flag signal according to the audio input signal, the voltage reduction threshold and the corresponding voltage reduction hysteresis threshold; determining whether a voltage reduction is indicated according to the first flag signal, and generating a voltage reduction control signal if the first flag signal indicates a voltage reduction; According to the step-down control signal, the step-down mode is turned on, and a step-down charge pump is used to reduce the power supply voltage of the power output stage circuit in the audio power amplifier from the first power supply voltage to the second power supply voltage, and the second power supply voltage is output to power the power output stage circuit, wherein the second power supply voltage is lower than the power supply voltage of the power supply.

2. The method according to claim 1, characterized in that The step-down charge pump is a 1 / 2 charge pump, and the difference between the second supply voltage and 1 / 2 times the power supply voltage is less than or equal to a preset difference.

3. The method according to claim 1, characterized in that The method further comprises: If the first flag signal indicates that the voltage should not be reduced, the pass-through mode is turned on and the power supply voltage is output to supply power to the power output stage circuit.

4. The method according to claim 1, characterized in that: If the differential signal of the audio input signal is less than or equal to the voltage reduction threshold, the first flag signal is used to indicate voltage reduction; If the differential signal of the audio input signal is greater than or equal to the voltage reduction hysteresis threshold corresponding to the voltage reduction threshold, the first flag signal is used to indicate no voltage reduction.

5. The method according to claim 4, characterized in that The voltage drop threshold and the corresponding voltage drop hysteresis threshold increase as the power supply voltage increases, and the voltage drop threshold and the corresponding voltage drop hysteresis threshold decrease as the power supply voltage decreases.

6. The method according to claim 5, characterized in that The power supply voltage is within a first voltage range, and the voltage drop threshold and the voltage drop hysteresis threshold correspond to the first voltage range; Among them, the first voltage range is a preset voltage range among multiple preset voltage ranges, each of the voltage ranges corresponds to a voltage drop threshold and a voltage drop hysteresis threshold, and the preset voltage range with a smaller voltage minimum value corresponds to smaller voltage drop threshold and voltage drop hysteresis threshold.

7. A power supply circuit, characterized in that: The power supply circuit comprises: A voltage detection circuit is connected to the power supply of the power supply circuit, and is used to generate a first flag signal according to an audio input signal of the audio power amplifier, a voltage reduction threshold and a corresponding voltage reduction hysteresis threshold; a control circuit connected to the voltage detection circuit, and configured to determine whether a voltage reduction is indicated according to the first flag signal, and generate a voltage reduction control signal if the first flag signal indicates a voltage reduction; An adaptive buck circuit is connected to the control circuit and is used to reduce the power supply voltage of the power output stage circuit in the audio power amplifier from a first power supply voltage to a second power supply voltage using a buck charge pump according to the buck control signal, and output the second power supply voltage to power the power output stage circuit, wherein the second power supply voltage is lower than the power supply voltage of the power supply.

8. The power supply circuit according to claim 7, characterized in that: The voltage detection circuit includes: a voltage generating circuit and a signal detection circuit, and the signal detection circuit includes a first comparator, a second comparator and a logic circuit, wherein: One end of the voltage generating circuit is connected to the power supply, the other end of the voltage generating circuit is connected to the negative input end of the first comparator and the negative input end of the second comparator, and the output end of the first comparator and the output end of the second comparator are connected to the logic circuit; The voltage generating circuit is used to generate the voltage reduction threshold and the corresponding voltage reduction hysteresis threshold according to the power supply voltage; The first comparator is used to generate a first comparison value according to the first differential signal of the audio input signal and the voltage drop threshold or the voltage drop hysteresis threshold; The second comparator is used to generate a second comparison value according to a second differential signal of the audio input signal and the voltage reduction threshold or the voltage reduction hysteresis threshold; The logic circuit is used to compare the first comparison value with the first comparison value to generate the first flag signal.

9. The power supply circuit according to claim 8, characterized in that: The positive input terminal of the first comparator and the positive input terminal of the second comparator are respectively connected to two input terminals of the first stage amplifier of the audio power amplifier. or, The positive input terminal of the first comparator and the positive input terminal of the second comparator are respectively connected to two output terminals of the first stage amplifier of the audio power amplifier. or, The positive input terminal of the first comparator and the positive input terminal of the second comparator are respectively connected to two input terminals of the second stage amplifier of the audio power amplifier. or, The positive input terminal of the first comparator and the positive input terminal of the second comparator are respectively connected to two output terminals of the second stage amplifier of the audio power amplifier.

10. The power supply circuit according to claim 8, characterized in that: The voltage generating circuit includes a first resistor and a second resistor, one end of the first resistor is connected to the power supply, the other end of the first resistor is connected to the voltage detection circuit and one end of the second resistor, the other end of the second resistor is grounded, and, The voltage generating circuit is used for performing voltage division processing on the power supply voltage to obtain the voltage reduction threshold or the voltage reduction hysteresis threshold; The resistance value of the first resistor is (1-k)*R, the resistance value of the second resistor is k*R, and the voltage reduction threshold is k times the power supply voltage.

11. The power supply circuit according to claim 8, characterized in that: The voltage generating circuit includes: a first resistor, a second resistor, an operational amplifier circuit, a first transistor, a second transistor, a third transistor, a third resistor, a fourth resistor and a fifth resistor, one end of the first resistor is connected to the power supply, the other end of the first resistor is connected to one end of the second resistor and the positive input end of the operational amplifier circuit, the negative input end of the operational amplifier circuit is connected to one end of the third resistor and the source of the first transistor, and the output end of the operational amplifier circuit is connected to the gate of the first transistor. The drain of the first transistor is connected to the gate and source of the second transistor and the gate of the third transistor, the drain of the second transistor is connected to the power supply, the gate of the second transistor is connected to the gate of the third transistor, the drain of the third transistor is connected to the power supply, the source of the third transistor is connected to one end of the fourth resistor, the other end of the fourth resistor is connected to one end of the fifth resistor, the other end of the second resistor, the other end of the third resistor and the other end of the fifth resistor are grounded, and, The voltage generating circuit is used to perform voltage division and voltage stabilization processing on the power supply voltage to obtain the voltage reduction threshold or the voltage reduction hysteresis threshold.

12. The power supply circuit according to claim 7, characterized in that: The adaptive buck circuit comprises: a charge pump power tube circuit, a flying capacitor, an output voltage detection circuit, and an undervoltage protection circuit, wherein the charge pump power tube circuit is connected in parallel with the flying capacitor, one input end of the charge pump power circuit is connected to the power supply, the other input end of the charge pump power circuit is connected to the output end of the control circuit, the output end of the charge pump power circuit is connected to one end of the output voltage detection circuit, the other end of the output voltage detection circuit is connected to one end of the undervoltage protection circuit, and the other end of the undervoltage protection circuit is connected to the control circuit; The charge pump power tube circuit is used to regulate the power supply voltage according to the voltage regulation control signal to output the supply voltage, wherein the voltage regulation control signal is used to control the switching state of the power tube switch in the charge pump power tube circuit to control the charging and / or discharging of the flying capacitor; The output voltage detection module is used to detect the supply voltage output by the charge pump power tube circuit to obtain a detection voltage; The undervoltage protection circuit is used to compare the detection voltage with the reference voltage to obtain a clamping signal, and the clamping signal is used to clamp the power supply voltage output by the charge pump power tube circuit; The control circuit is used to generate the voltage regulation control signal according to the clamp signal and the first flag signal.

13. The power supply circuit according to claim 12, characterized in that: The charge pump power tube circuit includes a first switch, a second switch, a third switch and a fourth switch. One end of the first switch is connected to the upper plate of the input capacitor and the power supply, and the other end of the first switch is connected to one end of the fourth switch and the upper plate of the flying capacitor; One end of the second switch is connected to the lower plate of the flying capacitor and one end of the third switch, and the other end of the second switch is connected to the other end of the fourth switch, the upper plate of the output capacitor and the power output stage circuit; The other end of the third switch is connected to the lower plate of the input capacitor and is grounded; The other end of the fourth switch is connected to the upper plate of the output capacitor, and the lower plate of the output capacitor is grounded.

14. The power supply circuit according to claim 13, characterized in that: The adaptive buck circuit is a 1 / 2 charge pump, the voltage regulation control signal is the buck control signal, and the clamp signal is used to clamp the supply voltage output by the charge pump power tube circuit to a voltage between 1 / 2 times the power supply voltage and the power supply voltage; The charge pump power tube circuit is used to control the first switch and the second switch to be turned on and the third switch and the fourth switch to be turned off according to the step-down control signal, so as to control the charging of the flying capacitor so that the voltage on the flying capacitor is 1 / 2 times the power supply voltage, and The first switch and the second switch are controlled to be turned off, and the third switch and the fourth switch are controlled to be turned on, so as to control the discharge of the flying capacitor, so that the power supply voltage output by the charge pump power tube circuit is the second power supply voltage, and the second power supply voltage is 1 / 2 times the power supply voltage.

15. The power supply circuit according to claim 14, characterized in that: The voltage regulation control signal is a through control signal, and the clamping signal is used to clamp the supply voltage output by the charge pump power tube circuit to the power supply voltage; The charge pump power tube circuit is used to control the first switch and the fourth switch to be turned on, and control the second switch and the third switch to be turned off according to the pass-through control signal, so as to control the supply voltage output by the charge pump power tube circuit to be the power supply voltage.

16. The power supply circuit according to claim 14, characterized in that: The second supply voltage is equal to 1 / 2 times the power supply voltage minus the product of the target current and the target impedance, wherein the target current is the current flowing through the charge pump power tube circuit, and the target impedance is the sum of the impedance of the fourth switch and the impedance of the third switch.

17. An audio device, characterized in that: The audio device comprises an audio power amplifier and a power supply circuit, wherein the audio power amplifier comprises a power output stage circuit, and the power supply circuit comprises: a voltage detection circuit connected to the power supply of the power supply circuit and generating a first flag signal according to the audio input signal of the audio power amplifier, a voltage reduction threshold and a corresponding voltage reduction hysteresis threshold, wherein the first flag signal is used to indicate whether to reduce the voltage; a control circuit connected to the voltage detection circuit, and configured to generate a voltage reduction control signal if the first flag signal indicates a voltage reduction; An adaptive buck circuit is connected to the control circuit and is used to respond to the buck control signal, use a buck charge pump to reduce the power supply voltage of the power output stage circuit in the audio power amplifier from a first power supply voltage to a second power supply voltage, and output the second power supply voltage to power the power output stage circuit, wherein the second power supply voltage is lower than the power supply voltage of the power supply of the power supply circuit.

18. The device according to claim 17, characterized in that The step-down charge pump is a 1 / 2 charge pump, and the difference between the second supply voltage and 1 / 2 times the power supply voltage is less than or equal to a preset difference.

19. The device according to claim 17 or 18, characterized in that The power output stage circuit includes a first H-bridge power tube circuit, a second H-bridge power tube circuit, and a switch circuit, wherein: The power output stage circuit is used to detect that the amplitude of the audio input signal is greater than a comparison threshold, control the switch circuit to be turned on, control the first H-bridge power tube circuit to input the audio input signal, and control the power supply voltage of the first H-bridge power tube circuit to be the first power supply voltage; The power output stage circuit is used to detect that the amplitude of the audio input signal is less than or equal to the comparison threshold, control the switch circuit to turn off, control the second H-bridge power tube circuit to input the audio input signal, and control the power supply voltage of the second H-bridge power tube circuit to be the second power supply voltage.

20. The device according to claim 19, characterized in that The first H-bridge power tube circuit and the second H-bridge power tube circuit each include four transistors; or, The first H-bridge power tube circuit includes four transistors, and the second H-bridge power tube circuit includes two transistors.

21. The device according to claim 17 or 18, characterized in that The power output stage includes a third H-bridge power tube circuit, wherein: The power output stage circuit is used to detect that the amplitude of the audio input signal is less than or equal to a comparison threshold, control the third H-bridge power tube circuit to input the audio input signal, and control the power supply voltage of the third H-bridge power tube circuit to be the second power supply voltage.

22. A chip, characterized in that: The chip comprises a circuit for implementing the audio device according to any one of claims 17 to 21.

23. An electronic device, characterized in that: The electronic device comprises the chip and a speaker as claimed in claim 22, wherein the chip is used to drive the speaker to produce sound.

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