Boost circuit, audio power amplifier, chip and electronic equipment
By connecting a shunt switch in parallel across the inductor of the Boost circuit and turning it on in shoot-through mode, the problem of low efficiency of the Boost circuit is solved, achieving a reduction in inductor loss and a lower cost in a more efficient shoot-through mode.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-09
- Publication Date
- 2026-03-13
AI Technical Summary
Existing Boost circuits are inefficient in shoot-through mode, leading to increased DC losses in the inductor, especially in high-power applications, resulting in system heat generation and increased costs.
A shunt switch is connected in parallel across the inductor in the Boost circuit and turned on in shoot-through mode. This makes the resistance through which the DC current flows the equivalent resistance of the inductor's DC resistance and the shunt switch's on-resistance in parallel, thus reducing DC losses.
It effectively improves the efficiency of the Boost circuit in shoot-through mode, reduces inductor DC loss, reduces system heat generation, and lowers costs.
Smart Images
Figure CN121663991A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of electronic circuit technology, and in particular to a boost circuit, an audio power amplifier, a chip, and an electronic device. Background Technology
[0002] A boost circuit is a switching-mode power converter used to increase a lower DC input voltage to a higher DC output voltage. Boost circuits play a crucial role in power and electronic products such as DC-DC power converters and power supply systems for audio chips. By adjusting the output voltage of the boost circuit, the diverse voltage and power requirements of power and electronic products in different application scenarios can be met.
[0003] Boost circuits can operate in either pass-through or boost mode. In pass-through mode, the inductor at the input of the Boost circuit is short-circuited, allowing the input voltage to be directly connected to the output, making it well-suited for low-power applications. However, in pass-through mode, the inductor at the input exhibits DC-DC losses, thus reducing the efficiency of the Boost circuit in this mode. Summary of the Invention
[0004] This application provides a boost circuit, an audio power amplifier, a chip, and an electronic device, which solves the problem of low efficiency of the boost circuit in the pass-through mode in the prior art, so as to improve the efficiency of the boost circuit in the pass-through mode.
[0005] In a first aspect, this application provides a boost circuit, the boost circuit comprising: a power supply terminal, an inductor, a shunt switch, a boost control circuit, and a voltage output terminal; The inductor is connected between the power supply terminal and the voltage input terminal of the boost control circuit, the shunt switch is connected in parallel with the inductor, and the output terminal of the boost control circuit is connected to the voltage output terminal. The boost control circuit is used to control the operating mode of the boost circuit. The shunt switch is used to turn on when the boost circuit is operating in shoot-through mode.
[0006] In an alternative embodiment, the shunt switch is also configured to disconnect when the boost circuit is operating in boost mode.
[0007] In one optional embodiment, the shunt switch is a MOSFET; the drain of the MOSFET is connected to the power supply terminal, and the source of the MOSFET is connected to the voltage input terminal of the boost control circuit.
[0008] In one optional embodiment, the boost control circuit includes a first switching transistor, a second switching transistor, and a first capacitor; The source of the first switching transistor and the drain of the second switching transistor are connected, and are connected to the inductor as the voltage input terminal of the boost control circuit; The drain of the first switching transistor is connected to ground through the first capacitor and is connected to the voltage output terminal as the output terminal of the boost control circuit; the source of the second switching transistor is connected to ground. In the direct-through mode, the first switch is turned on and the second switch is turned off.
[0009] In one optional embodiment, the boost control circuit includes a first switching transistor, a second switching transistor, a third switching transistor, a fourth switching transistor, a first capacitor, and a second capacitor; The source of the first switching transistor and the drain of the second switching transistor are connected, and are connected to the inductor as the voltage input terminal of the boost control circuit; The drain of the first switching transistor is connected to the source of the third switching transistor, the drain of the third switching transistor is connected to ground through the first capacitor, and the drain of the third switching transistor is connected to the voltage output terminal as the output terminal of the boost control circuit. The source of the second switching transistor is connected to the drain of the fourth switching transistor, and the source of the fourth switching transistor is connected to ground. The second capacitor is connected between the drain of the first switching transistor and the source of the second switching transistor; In the direct-through mode, the first and third switches are turned on, while the second and fourth switches are turned off.
[0010] In a second aspect, this application also provides an audio power amplifier, including a load drive circuit and a boost circuit as described in any of the first aspects above; The voltage output terminal of the boost circuit is connected to the power supply terminal of the load drive circuit.
[0011] In one alternative embodiment, the load drive circuit is an H-bridge architecture drive circuit.
[0012] Thirdly, this application also provides a boost chip, including the boost circuit as described in any of the first aspects above.
[0013] Fourthly, this application also provides an audio chip, including an audio power amplifier as described in any of the second aspects above.
[0014] Fifthly, this application also provides an electronic device, including a boost chip as described in the third aspect above or an audio chip as described in the fourth aspect above.
[0015] The boost circuit, audio power amplifier, chip, and electronic device provided in this application include a power supply terminal, an inductor, a shunt switch, a boost control circuit, and a voltage output terminal. The inductor is connected between the power supply terminal and the voltage input terminal of the boost control circuit. The shunt switch is connected in parallel with the inductor, and the output terminal of the boost control circuit is connected to the voltage output terminal. The boost control circuit controls the operating mode of the boost circuit; the shunt switch is used to conduct when the boost circuit operates in shoot-through mode. Thus, by conducting the shunt switch connected in parallel across the inductor in shoot-through mode, the resistance through which the DC current flows is the equivalent resistance of the parallel combination of the inductor's DC resistance and the shunt switch's on-resistance. This equivalent resistance is smaller than the inductor's DC resistance, effectively reducing the DC loss of the circuit during shoot-through and thereby improving the efficiency of the boost circuit in shoot-through mode. Attached Figure Description
[0016] Figure 1 This is one of the structural schematic diagrams of a boost circuit in related technologies; Figure 2 This is one of the structural schematic diagrams of the boost circuit provided in the embodiments of this application; Figure 3 This is a second schematic diagram of the boost circuit provided in the embodiments of this application; Figure 4 This is the third schematic diagram of the boost circuit provided in the embodiments of this application; Figure 5 This is one of the structural schematic diagrams of the audio power amplifier provided in the embodiments of this application; Figure 6 This is a second schematic diagram of the structure of the audio power amplifier provided in the embodiments of this application; Figure 7 This is one of the structural schematic diagrams of the electronic device provided in the embodiments of this application; Figure 8 This is a second schematic diagram of the structure of the electronic device provided in the embodiments of this application. Detailed Implementation
[0017] In this application, "at least one" means one or more, and "more than one" means two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can mean: A alone, A and B simultaneously, or B alone. A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, or c alone can mean: a alone, b alone, c alone, a combination of a and b, a combination of a and c, a combination of b and c, or a, b, and c. a, b, and c can be single or multiple. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.
[0018] The terms “center,” “longitudinal,” “lateral,” “up,” “down,” “left,” “right,” “front,” and “rear,” etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.
[0019] The terms "connected" and "connected" should be interpreted broadly. For example, in circuit structures, "connected" or "connected" can refer not only to physical connections but also to electrical or signal connections. This could be a direct connection (physical connection) or an indirect connection via at least one intermediate component, as long as the circuit is connected. It could also refer to the internal connection between two components. Similarly, a signal connection can refer to a connection via a circuit or a medium, such as radio waves. Those skilled in the art will understand the specific meaning of these terms in this application based on the specific circumstances.
[0020] A boost circuit is a circuit that can increase a lower DC input voltage to a higher DC output voltage. It plays a key role in power and electronic products such as DC-DC power converters and power supply systems for audio chips.
[0021] For example, in an audio playback system, an audio chip can be used to amplify a low-power audio signal to a level sufficient to drive a speaker or other load. A common architecture is a boost converter combined with a Class D audio power amplifier. When the audio signal is greater than or equal to a preset voltage threshold, the boost converter operates in boost mode; when the audio signal is less than the preset voltage threshold, the boost converter operates in pass-through mode.
[0022] Figure 1 A schematic diagram of a boost circuit in related technologies is shown, with reference to... Figure 1 As shown, the boost circuit includes a power supply terminal VBAT, an inductor L, a boost control circuit, and a voltage output terminal PVDD. The power supply terminal VBAT is connected to the input terminal of the boost control circuit through the inductor L, and the output terminal of the boost control circuit serves as the voltage output terminal PVDD of the entire boost circuit. In shoot-through mode, the inductor L at the input terminal of the boost circuit is short-circuited, resulting in DC losses and reducing the system efficiency in shoot-through mode. In applications with higher power requirements, such as automotive audio amplifier chips, the DC losses of the inductor L can also cause the system to generate heat, thereby increasing heat dissipation costs.
[0023] In related technologies, in order to reduce the DC loss of inductor L, inductors with special materials and special requirements for DC resistance (DCR) can be selected. However, the cost of such inductors is high, which also increases the cost of the entire system.
[0024] Based on this, this application provides a new boost circuit based on the bypass-boost topology. A shunt switch is connected in parallel across the inductor. When the circuit operates in shoot-through mode, the shunt switch connected in parallel across the inductor is turned on. At this time, the resistance through which the DC current passes is the equivalent resistance of the parallel connection of the DC resistance of the inductor and the on-resistance of the shunt switch. This equivalent resistance is less than the DC resistance of the inductor, thereby effectively reducing the DC loss of the circuit when the inductor is shoot-through, and thus improving the efficiency of the boost circuit in shoot-through mode.
[0025] Bypass-Boost is a power management technology that achieves stable voltage output by dynamically adjusting the circuit's operating mode. This operating mode can include pass-through mode and boost mode.
[0026] The following is combined Figures 2-4 The boost circuit provided in the embodiments of this application will be described in detail.
[0027] Figure 2 This paper shows one of the structural schematic diagrams of the boost circuit provided in the embodiments of this application, with reference to... Figure 2 As shown, the boost circuit may include a power supply terminal VBAT, an inductor L, a shunt switch QL, a boost control circuit 210, and a voltage output terminal PVDD. The inductor L is connected between the power supply terminal VBAT and the voltage input terminal of the boost control circuit 210. The shunt switch QL is connected in parallel with the inductor L. The output terminal of the boost control circuit 210 is connected to the voltage output terminal PVDD.
[0028] The boost control circuit 210 is used to control the operating mode of the boost circuit; the shunt switch QL is used to turn on the boost circuit when it is operating in the shoot-through mode.
[0029] Specifically, in the direct-through mode, the boost control circuit 210 directly connects the power supply terminal VBAT, the inductor L, and the voltage output terminal PVDD, and the power supply terminal VBAT directly supplies power to the load connected to the voltage output terminal PVDD. In this direct-through mode, the shunt switch QL is turned on. At this time, the DC current input to the power supply terminal VBAT will flow through the inductor L and the shunt switch QL. The DC current passing through the resistance across the inductor L can be expressed as the following formula (1): (1) in, R L This represents the resistance across the inductor L when direct current flows through it. R DCR This represents the DC resistance of inductor L. R dson This represents the on-resistance of the shunt switch QL. On-resistance refers to the resistance between the drain and source of the shunt switch QL when it is in the on-state.
[0030] According to formula (1), the resistance across the inductor L is the equivalent resistance of the DC resistance of the inductor L combined with the on-resistance of the shunt switch QL. The on-resistance of the shunt switch QL is equivalent to the resistance of the DC resistance of the inductor L combined with the DC resistance of the inductor L. R DCR Keeping the current equal, the DC current flows through the equivalent resistance across the inductor L. R L DC resistance only R DCR Half of it.
[0031] The DC loss flowing through the two ends of inductor L P It can be expressed as the following formula (2): (2) in, This is the DC current of the input signal at the power supply terminal VBAT.
[0032] Combining the above formulas (1) and (2), it can be seen that when a shunt switch QL is connected in parallel across the inductor L, the resistance of the DC current passing through the inductor L is significantly reduced. In this way, the DC loss across the inductor L can be greatly reduced.
[0033] according to Figure 2In one embodiment of the boost circuit shown, the boost control circuit 210 can also control the boost circuit to operate in boost mode. Boost mode is one of the basic operating modes of the boost circuit. In boost mode, the boost control circuit 210 controls the switching between the inductor L and the voltage output terminal PVDD, so that the inductor L is in a state of continuous energy storage and release, thereby realizing the boost function.
[0034] Specifically, during the stage when the boost control circuit 210 disconnects the inductor L from the voltage output terminal PVDD, the inductor L begins to store energy. During the stage when the boost control circuit 210 connects the inductor L to the voltage output terminal PVDD, the inductor L generates a self-induced voltage. This self-induced voltage is superimposed on the voltage input at the power supply terminal VBAT, generating a DC voltage at the voltage output terminal PVDD that is higher than the voltage input at the power supply terminal VBAT, thus achieving the boost effect.
[0035] When the boost control circuit 210 controls the boost circuit to operate in boost mode, the shunt switch QL is disconnected, thus ensuring that the boost circuit can start in boost mode normally.
[0036] For example, the shunt switch QL may include a metal-oxide-semiconductor field-effect transistor (MOS transistor). Specifically, the drain of the MOS transistor is connected to the power supply terminal VBAT, and the source of the MOS transistor is connected to the voltage input terminal of the boost control circuit 210.
[0037] For example, the MOSFET can be an N-type MOSFET or a P-type MOSFET.
[0038] For example, the boost control circuit 210 can be a two-level boost circuit (2L-Boost) architecture or a three-level boost circuit (3L-Boost) architecture.
[0039] Based on this, in one embodiment, taking a two-level boost circuit (2L-Boost) architecture as an example, Figure 3 A second schematic diagram of the boost circuit provided in this application is shown, with reference to... Figure 3 As shown, the boost circuit may include a power supply terminal VBAT, an inductor L, a shunt switch QL, a boost control circuit 210, and a voltage output terminal PVDD. The inductor L is connected between the power supply terminal VBAT and the voltage input terminal VSW of the boost control circuit 210. The shunt switch QL is connected in parallel with the inductor L. The output terminal of the boost control circuit 210 is connected to the voltage output terminal PVDD.
[0040] The boost control circuit 210 may include a first switching transistor Q1, a second switching transistor Q2, and a first capacitor Cout. The source of the first switching transistor Q1 and the drain of the second switching transistor Q2 are connected together, and the source (VSW) of the boost control circuit 210 is connected to the inductor L. The drain of the first switching transistor Q1 is connected to ground (GND) through the first capacitor Cout, and the drain (VSW) of the boost control circuit 210 is connected to the voltage output terminal (PVDD). The source of the second switching transistor Q2 is connected to ground (GND).
[0041] For example, the first switch Q1 and the second switch Q2 can be N-type MOSFETs or P-type MOSFETs.
[0042] according to Figure 3 The boost circuit shown has the following characteristics: In shoot-through mode, the shunt switch QL is on, the first switch Q1 is on, and the second switch Q2 is off. In boost mode, the shunt switch QL is off, and the first switch Q1 and the second switch Q2 alternately and complementaryly conduct. That is, the first switch Q1 can alternately be on and off; when the first switch Q1 is on, the second switch Q2 is off, and when the first switch Q1 is off, the second switch Q2 is on.
[0043] Specifically, when the boost circuit needs to operate in direct mode, the shunt switch QL can be turned on, and the first switch Q1 can be turned on while the second switch Q2 is turned off. At this time, the power signal input at the power supply terminal VBAT flows through the parallel inductor L and the shunt switch QL, and then directly reaches the voltage output terminal PVDD through the first switch Q1. The power supply terminal VBAT can directly supply power to the load connected to the voltage output terminal PVDD.
[0044] In this way, by connecting a shunt switch QL in parallel across the inductor L and controlling the shunt switch QL to conduct in shoot-through mode, the resistance of the DC current passing through the inductor L can be effectively reduced, thereby effectively reducing the DC loss of the circuit when the inductor L is in shoot-through mode, and thus improving the efficiency of the boost circuit in shoot-through mode.
[0045] In another embodiment, a three-level boost circuit (3L-Boost) architecture is used as an example. Figure 4 The third schematic diagram of the boost circuit provided in the embodiment of this application is shown. (Refer to...) Figure 4 As shown, the boost circuit may include a power supply terminal VBAT, an inductor L, a shunt switch QL, a boost control circuit 210, and a voltage output terminal PVDD. The inductor L is connected between the power supply terminal VBAT and the voltage input terminal VSW of the boost control circuit 210. The shunt switch QL is connected in parallel with the inductor L. The output terminal of the boost control circuit 210 is connected to the voltage output terminal PVDD.
[0046] The boost control circuit 210 may include a first switch Q1, a second switch Q2, a third switch Q3, a fourth switch Q4, a first capacitor Cout, and a second capacitor CF. The source of the first switch Q1 and the drain of the second switch Q2 are connected, and the source Q1 is connected to the inductor L as the voltage input terminal VSW of the boost control circuit 210. The drain of the first switch Q1 and the source of the third switch Q3 are connected. The drain of the third switch Q3 is connected to ground GND through the first capacitor Cout, and the drain of the third switch Q3 is connected to the voltage output terminal PVDD as the output terminal of the boost control circuit 210. The source of the second switch Q2 and the drain of the fourth switch Q4 are connected, and the source of the fourth switch Q4 is connected to ground GND. The second capacitor CF is connected between the drain of the first switch Q1 and the source of the second switch Q2.
[0047] For example, the first switch Q1, the second switch Q2, the third switch Q3 and the fourth switch Q4 can be N-type MOSFETs or P-type MOSFETs.
[0048] For example, the second capacitor CF can be a flying capacitor.
[0049] according to Figure 4 The boost circuit shown, in shoot-through mode, has shunt switch QL on, first switch Q1 and third switch Q3 on, and second switch Q2 and fourth switch Q4 off. In boost mode, shunt switch QL off, and first switch Q1, second switch Q2, third switch Q3 and fourth switch Q4 are switched on and off according to the existing 3L-Boost architecture's on / off logic, so that inductor L is in a state of continuous energy storage and release, thereby achieving the boost function.
[0050] Specifically, when the boost circuit needs to operate in direct-through mode, the shunt switch QL can be turned on, and the first switch Q1 and the third switch Q3 can be turned on simultaneously, while the second switch Q2 and the fourth switch Q4 can be turned off. At this time, the power signal input at the power supply terminal VBAT flows through the parallel inductor L and the shunt switch QL, and then through the first switch Q1 and the third switch Q3 directly to the voltage output terminal PVDD. The power supply terminal VBAT can then directly supply power to the load connected to the voltage output terminal PVDD.
[0051] In this way, by connecting a shunt switch QL in parallel across the inductor L and controlling the shunt switch QL to conduct in shoot-through mode, the resistance of the DC current passing through the inductor L can be effectively reduced, thereby effectively reducing the DC loss of the circuit when the inductor L is in shoot-through mode, and thus improving the efficiency of the boost circuit in shoot-through mode.
[0052] Based on the boost circuits of the above embodiments, assuming the power input signal at the power supply terminal VBAT has a power of 1W, a voltage of 4.4V, and a current of 0.23A, and that the inductance value of inductor L is 1 microhenry (μH) and the DC resistance of inductor L is... R DCR It is 36 milliohms (mR) and the on-resistance of the shunt switch QL. R dson Taking 12.9mR as an example, in the direct-through mode, the shunt switch QL is turned on. At this time, the DC loss flowing through the two ends of the inductor L can be expressed as the following formula (3): (3) Where mW is the power unit "milliwatt".
[0053] In the existing technology, no shunt switch QL is connected in parallel across the two ends of the inductor L. In this case, the DC loss flowing through the two ends of the inductor L can be expressed as the following formula (4): (4) Here, mW is the unit of power, "milliwatt".
[0054] According to formulas (3) and (4), compared with the prior art, the boost circuit provided in this application embodiment can greatly reduce the DC loss of inductor L by connecting the shunt switch QL in parallel across the inductor L and turning on the shunt switch QL in the direct mode. Its DC loss is only 26.38% of the original scheme, which greatly improves the efficiency of the system.
[0055] The boost circuit provided in this embodiment includes a power supply terminal, an inductor, a shunt switch, a boost control circuit, and a voltage output terminal. The inductor is connected between the power supply terminal and the voltage input terminal of the boost control circuit. The shunt switch is connected in parallel with the inductor, and the output terminal of the boost control circuit is connected to the voltage output terminal. The boost control circuit controls the operating mode of the boost circuit; the shunt switch is used to conduct when the boost circuit operates in shoot-through mode. Thus, by connecting the shunt switch in parallel across the inductor and conducting it in shoot-through mode, the resistance through which the DC current flows is the equivalent resistance of the parallel combination of the inductor's DC resistance and the shunt switch's on-resistance. This equivalent resistance is less than the inductor's DC resistance, effectively reducing DC losses in the circuit during shoot-through and thereby improving the efficiency of the boost circuit in shoot-through mode.
[0056] Based on the boost circuits of the above embodiments, this application also provides an audio power amplifier, which can be a Class D audio power amplifier. The following is in conjunction with... Figures 5-6 The audio power amplifier provided in the embodiments of this application will be described in detail.
[0057] Figure 5 This paper shows one of the structural schematic diagrams of an audio power amplifier provided in an embodiment of this application. (Refer to...) Figure 5 As shown, the audio power amplifier may include a boost circuit 510 and a load drive circuit 520, with the voltage output terminal PVDD of the boost circuit 510 connected to the power supply terminal of the load drive circuit 520.
[0058] Among them, the boost circuit 510 can be Figures 2 to 4 The boost circuit provided in any embodiment, for example, in Figure 5 In this context, the boost circuit 510 is... Figure 2 The following description uses the boost circuit provided in the corresponding embodiment as an example. The load drive circuit 520 is used to drive the speaker connected to the output terminal of the load drive circuit 520 under the action of the power supply voltage output by the voltage output terminal PVDD of the boost circuit 510, so that the speaker plays the sound signal to be played.
[0059] Specifically, for the audio signal to be played, amplitude and audio detection can be performed first to obtain amplitude information and audio signal. If the amplitude of the audio signal is greater than or equal to a preset amplitude threshold, the boost circuit 510 is activated in boost mode, and the shunt switch QL is turned off in boost mode. If the amplitude of the audio signal is less than the preset amplitude threshold, the boost circuit 510 is activated in pass-through mode, and the shunt switch QL is turned on in pass-through mode. This allows a DC supply voltage to be output at the voltage output terminal PVDD of the boost circuit 510. This DC supply voltage is approximately equal to the voltage input at the power supply terminal VBAT, enabling pass-through from the power supply terminal VBAT to the voltage output terminal PVDD. Under the influence of this supply voltage and the audio signal of the audio signal to be played, the load drive circuit 520 outputs a drive signal to the speaker connected to the output terminal of the load drive circuit 520, causing the speaker to play the audio signal.
[0060] In this way, by connecting a shunt switch QL in parallel across the inductor L of the boost circuit 510 and turning on the shunt switch QL in shoot-through mode, the resistance across the inductor L is equal to the equivalent resistance of the DC resistance of the inductor L and the on-resistance of the shunt switch QL in parallel. This equivalent resistance is less than the DC resistance of the inductor L, thereby effectively reducing the DC loss of the circuit when the inductor is shoot-through, and thus improving the efficiency of the entire audio power amplifier in shoot-through mode.
[0061] For example, the load drive circuit 510 can be a drive circuit of an H-bridge architecture.
[0062] Based on this, the boost circuit 510 adopts... Figure 3Taking the two-level Boost circuit (2L-Boost) architecture shown as an example, Figure 6 This is a second schematic diagram of the structure of the audio power amplifier provided in an embodiment of this application, with reference to... Figure 6 As shown, the load drive circuit 520 is a drive circuit with an H-bridge architecture. The first bridge arm output terminal A and the second bridge arm output terminal B can be connected to a speaker M, and the load drive circuit 520 can drive the speaker M.
[0063] Specifically, according to Figure 6 The audio power amplifier shown can first perform amplitude and audio detection on the audio signal to be played, obtaining amplitude information and audio signal. Based on the amplitude information, if the amplitude of the audio signal to be played is greater than or equal to a preset amplitude threshold, the shunt switch QL is turned off, and the boost circuit 510 is activated in boost mode. At this time, the first switch Q1 and the second switch Q2 in the boost control circuit 210 are alternately and complementaryly turned on, that is, the first switch Q1 can be alternately turned on and off. When the first switch Q1 is on, the second switch Q2 is off, and when the first switch Q1 is off, the second switch Q2 is on. In this way, the inductor L can be in a state of continuous energy storage and release, thereby realizing the function of boosting the voltage input at the power supply terminal VBAT to provide the boosted supply voltage to the load drive circuit 520 connected to the voltage output terminal PVDD.
[0064] If the amplitude of the audio signal to be played is less than a preset amplitude threshold, the boost circuit 510 is activated in direct-through mode, and the shunt switch QL is turned on in direct-through mode. At this time, the first switch Q1 is turned on and the second switch Q2 is turned off. The power signal input at the power supply terminal VBAT flows through the parallel inductor L and the shunt switch QL, and then directly to the voltage output terminal PVDD through the first switch Q1. The power supply terminal VBAT can directly supply power to the load drive circuit 520 connected to the voltage output terminal PVDD.
[0065] In this way, a DC power supply voltage can be output at the voltage output terminal PVDD of the boost circuit 510 according to the audio signal to be played. This DC power supply voltage is approximately equal to the voltage input at the power supply terminal VBAT, thus enabling a direct connection from the power supply terminal VBAT to the voltage output terminal PVDD. Under the action of this DC power supply voltage and driven by the audio signal of the audio signal to be played, the load drive circuit 520 of the H-bridge architecture changes the direction of the current flowing through the speaker M connected to the output terminal of the load drive circuit 520 of the H-bridge architecture and the average voltage of the speaker M by alternately turning on the switching transistors of the upper and lower bridge arms, thereby driving the speaker M to play the audio signal to be played and realizing the volume adjustment.
[0066] The audio power amplifier provided in this application embodiment connects a shunt switch QL in parallel across the inductor L of the boost circuit 510 and turns on the shunt switch QL in shoot-through mode. This makes the resistance across the inductor L the equivalent resistance of the DC resistance of the inductor L and the on-resistance of the shunt switch QL in parallel. This equivalent resistance is less than the DC resistance of the inductor L, thereby effectively reducing the DC loss of the circuit when the inductor L is shoot-through, thus improving the efficiency of the entire audio power amplifier in shoot-through mode and reducing the heat generation of the system.
[0067] This application also provides a boost chip, which may include the boost circuit described in any of the above embodiments. This boost chip can be applied in power or electronic products that require voltage boosting, such as in the power supply system of an audio chip. Through this boost chip, higher power output can be provided to the power supply system.
[0068] The boost chip provided in this application embodiment adopts the boost circuit as described in any of the above embodiments. By connecting a shunt switch in parallel across the inductor at the input terminal of the boost circuit and turning on the shunt switch in shoot-through mode, the resistance through which the DC current passes is the equivalent resistance of the parallel connection of the DC resistance of the inductor and the on-resistance of the shunt switch. This equivalent resistance is smaller than the DC resistance of the inductor, thereby effectively reducing the DC loss of the circuit when the inductor is shoot-through, thereby improving the efficiency of the boost chip in shoot-through mode and reducing the heat generation of the boost chip.
[0069] This application also provides an audio chip, which may include any of the embodiments described above. This audio power amplifier can be applied to electronic devices that require audio playback, such as mobile phones and computers.
[0070] The audio chip provided in this application embodiment employs an audio power amplifier as described in any of the above embodiments. This power amplifier uses a boost circuit as described in any of the above embodiments. By connecting a shunt switch in parallel across the inductor at the input terminal of the boost circuit and turning on the shunt switch in shoot-through mode, the resistance through which the DC current passes is the equivalent resistance of the parallel connection of the DC resistance of the inductor and the on-resistance of the shunt switch. This equivalent resistance is less than the DC resistance of the inductor, thereby effectively reducing the DC loss of the circuit when the inductor is shoot-through, thereby improving the efficiency of the audio chip in shoot-through mode and reducing the heat generation of the audio chip.
[0071] This application also provides an electronic device, which includes a boost chip as described above or an audio chip as described above.
[0072] For example, the electronic device is a device capable of playing audio, such as at least one of a mobile phone, computer, in-vehicle terminal, tablet computer, wearable device, and smart home device.
[0073] For example, Figure 7 One of the structural schematic diagrams of the electronic device provided in the embodiments of this application is shown below, with reference to Figure 7 As shown, the electronic device may include a first processor 710, a first communication interface 720, a first memory 730, a first communication bus 740, and a boost converter chip 750. The first processor 710, the first communication interface 720, the first memory 730, and the boost converter chip 750 can communicate with each other via the first communication bus 740.
[0074] The first processor 710 can call logic instructions in the first memory 730 to implement various functions of the electronic device. The boost chip 750 can be the boost chip provided in any of the above embodiments. The boost chip 750 can operate in pass-through mode or boost mode based on the logic instructions of the first processor 710 to provide higher power output for the power supply system in the electronic device.
[0075] For example, Figure 8 The second schematic diagram of the structure of the electronic device provided in the embodiment of this application is shown below. Figure 8 As shown, the electronic device may include a second processor 810, a second communication interface 820, a second memory 830, a second communication bus 840, and an audio chip 850. The second processor 810, the second communication interface 820, the second memory 830, and the audio chip 850 can communicate with each other via the second communication bus 840.
[0076] The second processor 810 can call logic instructions in the second memory 830 to implement various functions of the electronic device. The audio chip 850 can be any of the audio chips provided in the above embodiments. The audio chip 850 may include a boost chip provided in any embodiment of this application. This boost chip can operate in pass-through mode or boost mode based on the logic instructions of the second processor 810, providing higher power output to the power supply system of the audio chip 850. The audio chip 850 can play sound signals based on the logic instructions of the second processor 810.
[0077] The electronic device provided in this application embodiment can achieve the beneficial effects of the boost chip as described in any of the above embodiments, or the beneficial effects of the audio chip as described in any of the above embodiments, which will not be repeated here.
[0078] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the disclosure herein. This application is intended to cover any variations, uses, or adaptations thereof that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this application are indicated by the claims.
Claims
1. A boost circuit, characterized in that, The boost circuit includes: a power supply terminal, an inductor, a shunt switch, a boost control circuit, and a voltage output terminal; The inductor is connected between the power supply terminal and the voltage input terminal of the boost control circuit, the shunt switch is connected in parallel with the inductor, and the output terminal of the boost control circuit is connected to the voltage output terminal. The boost control circuit is used to control the operating mode of the boost circuit. The shunt switch is used to turn on when the boost circuit is operating in shoot-through mode.
2. The boost circuit according to claim 1, characterized in that, The shunt switch is also used to disconnect when the boost circuit is operating in boost mode.
3. The boost circuit according to claim 1, characterized in that, The shunt switch is a MOSFET; the drain of the MOSFET is connected to the power supply terminal, and the source of the MOSFET is connected to the voltage input terminal of the boost control circuit.
4. The boost circuit according to any one of claims 1 to 3, characterized in that, The boost control circuit includes a first switching transistor, a second switching transistor, and a first capacitor; The source of the first switching transistor and the drain of the second switching transistor are connected, and are connected to the inductor as the voltage input terminal of the boost control circuit; The drain of the first switching transistor is connected to ground through the first capacitor and is connected to the voltage output terminal as the output terminal of the boost control circuit; the source of the second switching transistor is connected to ground. In the direct-through mode, the first switch is turned on and the second switch is turned off.
5. The boost circuit according to any one of claims 1 to 3, characterized in that, The boost control circuit includes a first switching transistor, a second switching transistor, a third switching transistor, a fourth switching transistor, a first capacitor, and a second capacitor. The source of the first switching transistor and the drain of the second switching transistor are connected, and are connected to the inductor as the voltage input terminal of the boost control circuit; The drain of the first switching transistor is connected to the source of the third switching transistor, the drain of the third switching transistor is connected to ground through the first capacitor, and the drain of the third switching transistor is connected to the voltage output terminal as the output terminal of the boost control circuit. The source of the second switching transistor is connected to the drain of the fourth switching transistor, and the source of the fourth switching transistor is connected to ground. The second capacitor is connected between the drain of the first switching transistor and the source of the second switching transistor; In the direct-through mode, the first and third switches are turned on, while the second and fourth switches are turned off.
6. An audio power amplifier, characterized in that, Includes a load drive circuit and a boost circuit as described in any one of claims 1 to 5; The voltage output terminal of the boost circuit is connected to the power supply terminal of the load drive circuit.
7. The audio power amplifier according to claim 6, characterized in that, The load drive circuit is an H-bridge architecture drive circuit.
8. A boost converter chip, characterized in that, Includes the boost circuit as described in any one of claims 1 to 5.
9. An audio chip, characterized in that, Includes the audio power amplifier as described in claim 6 or 7.
10. An electronic device, characterized in that, This includes the boost chip as described in claim 8 or the audio chip as described in claim 9.