A boost circuit based on a sampling capacitance multiplexing boost amplifier

Abstract

The application discloses a kind of based on sampling capacitor multiplexing boost amplifier's boost circuit, including boost amplifier, sampling capacitor, flying capacitor, feedback resistance and switch network.Wherein, boost amplifier is used to output boost voltage to flying capacitor, sampling capacitor is used to sample the boost voltage output by boost amplifier, flying capacitor is used to carry out periodic charge and discharge to keep the constant of boost circuit output voltage, feedback resistance is used to carry out feedback sampling to boost circuit output voltage;Switch network has multiple designs, and can switch the working mode of boost circuit.The application samples the boost voltage of boost amplifier at the previous moment by sampling capacitor, and uses the same boost amplifier to charge flying capacitor to the potential of the boost voltage at the previous moment using sampling capacitor at the next moment, which can save the use of charging amplifier, while improving the overall resource utilization of the circuit.

Description

Technical Field

[0001] This invention relates to the field of boost circuit technology, and more specifically to a boost circuit based on a sampling capacitor multiplexed boost amplifier. Background Technology

[0002] Traditional boost circuits typically employ a dual-amplifier design to achieve their function. One amplifier acts as a charging amplifier, specifically used to charge the flying capacitor; while the other acts as a boost amplifier, responsible for generating an adjustable voltage and superimposing it on the voltage of the flying capacitor to achieve boost output.

[0003] However, this configuration has significant drawbacks. First, because it requires two independent amplifiers, the overall size of the boost circuit is usually large, which is a constraint in miniaturized electronic devices. Second, there is a timing inconsistency between the two amplifiers; specifically, during the boost process, the charging amplifier is idle, while during the charging phase, the boost amplifier is not used.

[0004] This timing mismatch further leads to resource waste, as each amplifier cannot effectively participate in circuit operation during its inactive periods, reducing overall resource utilization. Furthermore, the large size limits the circuit's applicability in compact applications. Summary of the Invention

[0005] In view of this, embodiments of the present invention provide a boost circuit based on a sampling capacitor multiplexed boost amplifier.

[0006] The first aspect of the present invention provides a boost circuit based on a sampling capacitor multiplexed boost amplifier, including a boost amplifier, a sampling capacitor, a flying capacitor, a feedback resistor, and a switching network;

[0007] The boost amplifier is used to output a boost voltage to the flying capacitor, the sampling capacitor is used to sample the boost voltage output by the boost amplifier, the flying capacitor is used to perform periodic charging and discharging to keep the output voltage of the boost circuit constant, and the feedback resistor is used to perform feedback sampling of the output voltage of the boost circuit.

[0008] The switching network includes a first switch, a second switch, a third switch, a fourth switch, and a fifth switch; wherein, the first switch is disposed between the flying capacitor and the output node of the boost circuit; the second switch is disposed between the flying capacitor and the output terminal of the boost amplifier; the third switch is disposed between the sampling capacitor and the boost amplifier; the fourth switch is disposed between the reference voltage input and the reference input terminal of the boost amplifier; and the fifth switch is disposed between the feedback resistor and the feedback input terminal of the boost amplifier; the operating mode of the boost circuit is switched through the switching network.

[0009] Furthermore, the first switch is a single-pole double-throw switch, with the stationary terminal connected to one end of the flying capacitor, the first moving terminal connected to the output terminal of the boost amplifier, and the second moving terminal connected to the output node of the boost circuit;

[0010] The second switch is a single-pole double-throw switch. The stationary terminal is connected to the end of the flying capacitor furthest from the first switch, the first moving terminal is connected to the output terminal of the boost amplifier, and the second moving terminal is connected to signal ground.

[0011] The third switch is a single-pole double-throw switch, with the stationary terminal connected to one end of the sampling capacitor, the first moving terminal connected to the reference input terminal of the boost amplifier, and the second moving terminal connected to the output terminal of the boost amplifier.

[0012] The fourth switch is a single-pole single-throw switch, with one end connected to the reference voltage input and the other end connected to the reference input terminal of the boost amplifier; the fourth switch is further away from the reference input terminal of the boost amplifier relative to the connection node of the third switch.

[0013] The fifth switch is a single-pole double-throw switch. The stationary terminal is connected to the reference input terminal of the boost amplifier, the first moving terminal is connected to the output terminal of the boost amplifier, and the second moving terminal is connected to the feedback resistor.

[0014] Furthermore, the boost circuit has a boost operating mode. In the boost operating mode, the first switch connects the flying capacitor and the output node of the boost circuit; the second switch connects the output terminal of the boost amplifier and the flying capacitor; the third switch connects the output terminal of the boost amplifier and the sampling capacitor; the fourth switch is in the ON state; and the fifth switch connects the feedback resistor and the feedback input terminal of the boost amplifier.

[0015] In boost mode, the boost amplifier dynamically adjusts the boost voltage output by comparing the reference voltage input at the reference input terminal with the feedback voltage at the feedback input terminal. The boost voltage is superimposed with the discharge voltage of the flying capacitor to serve as the output voltage of the boost circuit. The boost voltage is also sampled by the sampling capacitor to keep the voltage of the sampling capacitor at the potential of the boost voltage.

[0016] Furthermore, the boost circuit also has a charging operating mode. In the charging operating mode, the first switch connects the flying capacitor and the output terminal of the boost amplifier; the second switch connects the flying capacitor and signal ground; the third switch connects the sampling capacitor and the reference input terminal of the boost amplifier; the fourth switch is in the off state; and the fifth switch connects the output terminal of the boost amplifier and the reference input terminal.

[0017] In charging mode, the sampling capacitor inputs the boost voltage sampled in the previous boost mode to the reference input of the boost amplifier. Simultaneously, the boost voltage output by the boost amplifier at the current moment is input through the feedback input, making the boost voltage output by the boost amplifier at the current moment equal to the boost voltage at the previous moment. The boost voltage output at the current moment is used to charge the flying capacitor, so that the voltage of the flying capacitor remains at the potential of the boost voltage at the previous moment, and is superimposed on the boost voltage output by the boost amplifier at the next moment in the next boost mode.

[0018] Another aspect of the present invention discloses a boost circuit based on a sampling capacitor multiplexed boost amplifier, including a boost amplifier, a sampling capacitor, a flying capacitor, a feedback resistor, and a switching network;

[0019] The boost amplifier is used to output a boost voltage to the flying capacitor, the sampling capacitor is used to sample the boost voltage output by the boost amplifier, the flying capacitor is used to perform periodic charging and discharging to maintain a constant output voltage of the boost circuit, and the feedback resistor is used to perform feedback sampling of the output voltage of the boost circuit; the sampling capacitor is connected between the output terminal and the feedback input terminal of the boost amplifier.

[0020] The switching network includes a first switch, a second switch, and a sixth switch; wherein, the first switch is disposed between the flying capacitor and the output node of the boost circuit; the second switch is disposed between the flying capacitor and the output terminal of the boost amplifier; the sixth switch is disposed between the middle of the feedback resistor and the feedback input terminal of the boost amplifier, and is further away from the feedback input terminal of the boost amplifier relative to the connection node of the sampling capacitor; the operating mode of the boost circuit is switched through the switching network.

[0021] Furthermore, the boost circuit has a boost operating mode. In the boost operating mode, the first switch connects the flying capacitor and the output node of the boost circuit; the second switch connects the output terminal of the boost amplifier and the flying capacitor; and the sixth switch is in the ON state.

[0022] In boost mode, the boost voltage output from the boost amplifier is superimposed on the discharge voltage of the flying capacitor to serve as the output voltage of the boost circuit; the voltage potential of the sampling capacitor is the difference between the boost voltage and the feedback voltage at the feedback input of the boost amplifier.

[0023] Furthermore, the boost circuit also has a charging mode. In the charging mode, the first switch connects the flying capacitor and the output terminal of the boost amplifier; the second switch connects the flying capacitor and signal ground; and the sixth switch is in the off state.

[0024] In charging mode, the potential at the feedback input of the boost amplifier is the potential of the reference voltage. The potential at the output of the boost amplifier is fixed to the potential of the boost voltage at the previous moment through the sampling capacitor. At the same time, the boost amplifier charges the flying capacitor, so that the voltage of the flying capacitor is maintained at the potential of the boost voltage at the previous moment, and is superimposed with the boost voltage output of the boost amplifier at the next moment in the boost operation mode.

[0025] Another aspect of the present invention discloses a boost circuit based on a sampling capacitor multiplexed boost amplifier, including a boost amplifier, a sampling capacitor, a flying capacitor, a feedback resistor, and a switching network;

[0026] The boost amplifier is used to output a boost voltage to the flying capacitor, the sampling capacitor is used to sample the boost voltage output by the boost amplifier, the flying capacitor is used to perform periodic charging and discharging to keep the output voltage of the boost circuit constant, and the feedback resistor is used to perform feedback sampling of the output voltage of the boost circuit.

[0027] The switching network includes a first switch, a second switch, and a seventh switch; wherein, the first switch is disposed between the flying capacitor and the output node of the boost circuit; the second switch is disposed between the flying capacitor and the output terminal of the boost amplifier; the seventh switch is disposed between the output stage MOSFET and the current mirror circuit inside the boost amplifier, and is used to control the potential of the boost voltage output by the output stage MOSFET; the sampling capacitor is connected between the gate and source of the output stage MOSFET inside the boost amplifier.

[0028] Furthermore, the boost circuit has a boost operating mode. In the boost operating mode, the first switch connects the flying capacitor and the output node of the boost circuit; the second switch connects the output terminal of the boost amplifier and the flying capacitor; and the seventh switch is in the ON state.

[0029] In boost mode, the boost voltage output from the boost amplifier is superimposed with the discharge voltage of the flying capacitor to serve as the output voltage of the boost circuit; the voltage potential of the sampling capacitor is the potential difference between the gate and source of the MOS transistor in the output stage of the boost amplifier.

[0030] Furthermore, the boost circuit also has a charging operating mode. In the charging operating mode, the first switch connects the flying capacitor and the output terminal of the boost amplifier; the second switch connects the flying capacitor and signal ground; and the seventh switch is in the open state.

[0031] In the charging mode, the potential of the gate of the output stage MOS transistor inside the boost amplifier is fixed. The potential of the source of the output stage MOS transistor is fixed to the potential of the boost voltage at the previous moment through the sampling capacitor. At the same time, the boost amplifier charges the flying capacitor so that the voltage of the flying capacitor is maintained at the potential of the boost voltage at the previous moment, and is superimposed with the boost voltage output by the boost amplifier at the next moment in the boost mode.

[0032] The embodiments of the present invention have the following beneficial effects: The boost circuit based on the sampling capacitor multiplexing boost amplifier disclosed in the present invention samples the boost voltage of the boost amplifier at the previous moment through the sampling capacitor, and uses the same boost amplifier in conjunction with the sampling capacitor to charge the flying capacitor to the potential of the boost voltage at the previous moment at the next moment. This can eliminate the need for a charging amplifier and improve the overall resource utilization of the circuit.

[0033] Additional aspects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description or may be learned by practice of the invention. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0035] Figure 1This is a circuit wiring diagram of the boost circuit based on the sampling capacitor multiplexing boost amplifier according to the first embodiment of the present invention in boost mode.

[0036] Figure 2 This is a circuit wiring diagram of the boost circuit based on the sampling capacitor multiplexing boost amplifier in the charging working mode according to the first embodiment of the present invention.

[0037] Figure 3 This is a circuit wiring diagram of the boost circuit based on the sampling capacitor multiplexing boost amplifier according to the second embodiment of the present invention in boost mode.

[0038] Figure 4 This is a circuit wiring diagram of the boost circuit based on the sampling capacitor multiplexing boost amplifier according to the second embodiment of the present invention in the charging working mode;

[0039] Figure 5 This is a circuit wiring diagram of the boost circuit based on the sampling capacitor multiplexing boost amplifier according to the third embodiment of the present invention in boost mode.

[0040] Figure 6 This is a circuit wiring diagram of the boost circuit based on the sampling capacitor multiplexing boost amplifier according to the third embodiment of the present invention in the charging working mode;

[0041] Figure 7 This is a schematic diagram of the internal equivalent circuit of the boost amplifier in the boost circuit based on the sampling capacitor multiplexing boost amplifier according to the third embodiment of the present invention.

[0042] Figure reference numerals: SW1 - First switch, SW2 - Second switch, SW3 - Third switch, SW4 - Fourth switch, SW5 - Fifth switch, SW6 - Sixth switch, SW7 - Seventh switch, Vbt - Boost voltage, Vref - Reference voltage, Vset - Boost circuit output voltage, VFB - Feedback voltage. Detailed Implementation

[0043] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0044] In a traditional dual-amplifier circuit, a separate charging amplifier is used during the charging phase to generate a fixed voltage Vcg, which is then used to charge the flying capacitor. During the boost phase, another boost amplifier is used to generate an adjustable boost voltage Vbt, which serves as the input power supply. The voltage Vcg stored in the flying capacitor is then superimposed on the input voltage Vbt and output. The feedback regulation of the boost amplifier keeps Vset at a certain voltage, i.e., Vset = Vbt + Vcg.

[0045] Traditional designs require two independent amplifiers, resulting in a typically large overall size for the boost circuit, which is a constraint in miniaturized electronic devices. Secondly, there is a timing mismatch between the two amplifiers: during the boost process, the charging amplifier is idle, while during the charging phase, the boost amplifier is not used. This timing mismatch further wastes resources, as each amplifier cannot effectively participate in circuit operation during its inactive periods, reducing overall resource utilization. Furthermore, the large size limits the circuit's applicability in compact applications.

[0046] To solve the above problems, such as Figure 1 , 2 As shown, the first embodiment of the present invention discloses a boost circuit based on a sampling capacitor multiplexed boost amplifier, including a boost amplifier, a sampling capacitor, a flying capacitor, a feedback resistor, and a switching network;

[0047] Among them, the boost amplifier is used to output the boost voltage to the flying capacitor, the sampling capacitor is used to sample the boost voltage output by the boost amplifier, the flying capacitor is used to perform periodic charging and discharging to keep the output voltage of the boost circuit constant, and the feedback resistor is used to perform feedback sampling of the output voltage of the boost circuit.

[0048] The switching network includes a first switch SW1, a second switch SW2, a third switch SW3, a fourth switch SW4, and a fifth switch SW5. The first switch SW1 is located between the flying capacitor and the output node of the boost circuit; the second switch SW2 is located between the flying capacitor and the output terminal of the boost amplifier; the third switch SW3 is located between the sampling capacitor and the boost amplifier; the fourth switch SW4 is located between the reference voltage input and the reference input terminal of the boost amplifier; and the fifth switch SW5 is located between the feedback resistor and the feedback input terminal of the boost amplifier. The switching network switches the operating mode of the boost circuit.

[0049] In this embodiment of the invention, a sampling capacitor is used instead of a charging amplifier, enabling the boost amplifier to stably generate the required output voltage Vset, thus optimizing amplifier performance. After generating the output voltage Vset, a smoothing capacitor is also used to smooth the output voltage, reducing ripple.

[0050] Preferably, the first switch SW1 is a single-pole double-throw switch, with the stationary terminal connected to one end of the flying capacitor, the first moving terminal connected to the output terminal of the boost amplifier, and the second moving terminal connected to the output node of the boost circuit.

[0051] The second switch SW2 is a single-pole double-throw switch. The stationary terminal is connected to the end of the flying capacitor furthest from the first switch SW1, the first moving terminal is connected to the output terminal of the boost amplifier, and the second moving terminal is connected to signal ground.

[0052] The third switch SW3 is a single-pole double-throw switch. The stationary terminal is connected to one end of the sampling capacitor, the first moving terminal is connected to the reference input terminal of the boost amplifier, and the second moving terminal is connected to the output terminal of the boost amplifier.

[0053] The fourth switch SW4 is a single-pole single-throw switch, with one end connected to the reference voltage input and the other end connected to the reference input terminal of the boost amplifier; the connection point of the fourth switch SW4 is further away from the reference input terminal of the boost amplifier than that of the third switch SW3.

[0054] The fifth switch SW5 is a single-pole double-throw switch. The stationary terminal is connected to the reference input terminal of the boost amplifier, the first moving terminal is connected to the output terminal of the boost amplifier, and the second moving terminal is connected to the feedback resistor.

[0055] As a specific embodiment, the boost circuit has a boost operating mode. In the boost operating mode, the first switch SW1 is connected to the flying capacitor and the output node of the boost circuit; the second switch SW2 is connected to the output terminal of the boost amplifier and the flying capacitor; the third switch SW3 is connected to the output terminal of the boost amplifier and the sampling capacitor; the fourth switch SW4 is in the ON state; and the fifth switch SW5 is connected to the feedback resistor and the feedback input terminal of the boost amplifier.

[0056] In boost mode, the boost amplifier dynamically adjusts the boost voltage output by comparing the reference voltage at the reference input terminal with the feedback voltage at the feedback input terminal. The boost voltage is superimposed with the discharge voltage of the flying capacitor as the output voltage of the boost circuit. The boost voltage is also sampled by the sampling capacitor to keep the voltage of the sampling capacitor at the potential of the boost voltage.

[0057] In boost mode, the boost amplifier compares VFB and Vref to adjust its output boost voltage Vbt, so that Vset is output stably (at this time, Vset = Vbt + flying capacitor voltage). At the same time, the boost voltage Vbt is written to the sampling capacitor to charge it to Vbt.

[0058] As a specific embodiment, the boost circuit also has a charging operating mode. In the charging operating mode, the first switch SW1 connects the flying capacitor and the output terminal of the boost amplifier; the second switch SW2 connects the flying capacitor and signal ground; the third switch SW3 connects the sampling capacitor and the reference input terminal of the boost amplifier; the fourth switch SW4 is in the off state; and the fifth switch SW5 connects the output terminal of the boost amplifier and the reference input terminal.

[0059] In charging mode, the sampling capacitor inputs the boost voltage sampled in the previous boost mode to the reference input of the boost amplifier. At the same time, the boost voltage output by the boost amplifier at the current moment is input through the feedback input, making the boost voltage output by the boost amplifier at the current moment equal to the boost voltage at the previous moment. The boost voltage output at the current moment is used to charge the flying capacitor, so that the voltage of the flying capacitor is maintained at the potential of the boost voltage at the previous moment, and is superimposed with the boost voltage output by the boost amplifier at the next moment in the next boost mode.

[0060] In charging mode, the previous boost voltage Vbt, stored in the sampling capacitor, is applied to the reference input of the boost amplifier via the third switch SW3. This forms a feedback loop at the feedback input, causing the boost amplifier to adjust the output boost voltage to match the previous boost voltage Vbt and store it in the flying capacitor. In the next boost mode, the output voltage Vset of the boost circuit will be equal to the sum of the next boost voltage and the previous boost voltage stored in the flying capacitor.

[0061] In this embodiment of the invention, by closing switch SW3 during the boost phase, the sampling capacitor directly samples and stores the output voltage Vbt of the boost amplifier at this time. In the subsequent charging phase, SW3 is opened and SW4 and SW5 are closed, connecting the sampling capacitor storing the Vbt voltage to the amplifier's output node, forcing the node potential to be Vbt, thereby charging the flying capacitor with this voltage. In this way, the flying capacitor voltage is always equal to the adjustment voltage Vbt from the previous boost phase, and through negative feedback, the output voltage is stabilized at Vset = Vbt + Vbt.

[0062] For example, assuming an 8V Vset output is required, the traditional solution requires setting Vset=8V and Vcg=5V, so Vset=5V+3V=8V. However, in this embodiment of the invention, only Vbt=4V needs to be set, so Vset=4V+4V=8V; thus, this embodiment of the invention achieves boost operation using a single amplifier.

[0063] The second embodiment of the present invention discloses another boost circuit based on a sampling capacitor multiplexed boost amplifier, such as... Figure 3 , 4As shown, it includes a boost amplifier, a sampling capacitor, a flying capacitor, a feedback resistor, and a switching network;

[0064] The boost amplifier is used to output a boosted voltage to the flying capacitor, the sampling capacitor is used to sample the boosted voltage output by the boost amplifier, the flying capacitor is used to perform periodic charging and discharging to keep the output voltage of the boost circuit constant, and the feedback resistor is used to sample the output voltage of the boost circuit. The sampling capacitor is connected between the output terminal of the boost amplifier and the feedback input terminal.

[0065] The switching network includes a first switch SW1, a second switch SW2, and a sixth switch SW6. The first switch SW1 is located between the flying capacitor and the output node of the boost circuit. The second switch SW2 is located between the flying capacitor and the output terminal of the boost amplifier. The sixth switch SW6 is located between the middle of the feedback resistor and the feedback input terminal of the boost amplifier, and is further away from the feedback input terminal of the boost amplifier than the connection node of the sampling capacitor. The operating mode of the boost circuit is switched through the switching network.

[0066] As a specific embodiment, the boost circuit has a boost operating mode. In the boost operating mode, the first switch SW1 is connected to the flying capacitor and the output node of the boost circuit; the second switch SW2 is connected to the output terminal of the boost amplifier and the flying capacitor; and the sixth switch SW6 is in the ON state.

[0067] In boost mode, the boost voltage output from the boost amplifier is superimposed on the discharge voltage of the flying capacitor to serve as the output voltage of the boost circuit; the voltage potential of the sampling capacitor is the difference between the boost voltage and the feedback voltage.

[0068] As a specific embodiment, the boost circuit also has a charging operating mode. In the charging operating mode, the first switch SW1 connects the flying capacitor and the output terminal of the boost amplifier; the second switch SW2 connects the flying capacitor and the signal ground; and the sixth switch SW6 is in the off state.

[0069] In charging mode, the potential at the feedback input of the boost amplifier is the potential of the reference voltage. The potential at the output of the boost amplifier is fixed to the potential of the boost voltage at the previous moment through the sampling capacitor. At the same time, the boost amplifier charges the flying capacitor, so that the voltage of the flying capacitor is maintained at the potential of the boost voltage at the previous moment, and is superimposed with the boost voltage output of the boost amplifier at the next moment in the boost operation mode.

[0070] In the second embodiment of this invention, during the boost phase, switch SW6 is closed, connecting the sampling capacitor between the amplifier output Vbt and the reference voltage Vref. The capacitor charges to the voltage difference Vbt - Vref, and simultaneously, the complete negative feedback loop ensures VFB = Vref, stabilizing Vset. During the charging phase, SW6 is opened, the sampling capacitor floats, and its voltage difference is maintained. To maintain this voltage difference, the side of the capacitor connected to the amplifier output forces the node potential to remain at approximately Vbt, thereby providing the charging voltage Vbt for the flying capacitor. It is evident that this embodiment of the invention records the relative relationship between Vbt and Vref through the sampling capacitor, reproduces Vbt during the charging phase, and thus achieves a stable output of Vset.

[0071] The third embodiment of the present invention discloses yet another boost circuit based on a sampling capacitor multiplexed boost amplifier, such as... Figure 5 , 6 As shown in Figure 7, it includes a boost amplifier, a sampling capacitor, a flying capacitor, a feedback resistor, and a switching network;

[0072] Among them, the boost amplifier is used to output the boost voltage to the flying capacitor, the sampling capacitor is used to sample the boost voltage output by the boost amplifier, the flying capacitor is used to perform periodic charging and discharging to keep the output voltage of the boost circuit constant, and the feedback resistor is used to perform feedback sampling of the output voltage of the boost circuit.

[0073] The switching network includes a first switch SW1, a second switch SW2, and a seventh switch SW7. The first switch SW1 is located between the flying capacitor and the output node of the boost circuit. The second switch SW2 is located between the flying capacitor and the output terminal of the boost amplifier. The sixth switch SW6 is located between the output stage MOSFET and the current mirror circuit inside the boost amplifier and is used to control the potential of the boost voltage output by the output stage MOSFET. The sampling capacitor is connected between the gate and source of the output stage MOSFET inside the boost amplifier.

[0074] As a specific embodiment, the boost circuit has a boost operating mode. In the boost operating mode, the first switch SW1 is connected to the flying capacitor and the output node of the boost circuit; the second switch SW2 is connected to the output terminal of the boost amplifier and the flying capacitor; and the seventh switch SW7 is in the ON state.

[0075] In boost mode, the boost voltage output by the boost amplifier is superimposed with the discharge voltage of the flying capacitor to serve as the output voltage of the boost circuit; the voltage potential of the sampling capacitor is the potential difference between the gate and source of the MOS transistor in the output stage of the boost amplifier.

[0076] As a specific embodiment, the boost circuit also has a charging operation mode. In the charging operation mode, the first switch SW1 connects the flying capacitor and the output terminal of the boost amplifier; the second switch SW2 connects the flying capacitor and the signal ground; and the seventh switch SW7 is in the off state.

[0077] In the charging mode, the potential of the gate of the output stage MOSFET inside the boost amplifier is fixed. The potential of the source of the output stage MOSFET is fixed to the potential of the boost voltage at the previous moment through the sampling capacitor. At the same time, the boost amplifier charges the flying capacitor so that the voltage of the flying capacitor is maintained at the potential of the boost voltage at the previous moment. In the next boost mode, it is superimposed on the boost voltage output by the boost amplifier at the next moment.

[0078] In the third embodiment of this invention, during the boost phase, the seventh switch SW7 is closed, the amplifier performs normal negative feedback regulation, and outputs a stable Vbt. The Miller capacitor acts as a compensation capacitor and naturally records the circuit state. During the charging phase, the seventh switch SW7 is open, the Miller capacitor is isolated from the amplifier's preamplifier stage, and its voltage is locked, thus "freezing" the gate state of the output stage MOSFET. This allows the amplifier's output voltage Vbt to be automatically maintained near the previous state, and this voltage is used to charge the flying capacitor. Ultimately, by adjusting a single Vbt, Vset = Vbt + Vbt is stabilized.

[0079] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0080] Furthermore, the terms "first," "second," etc., used in the embodiments of this invention are for descriptive purposes only and should not be construed as indicating or implying relative importance, or implicitly specifying the number of technical features indicated in this embodiment. Therefore, features defined with terms such as "first" and "second" in the embodiments of this invention can explicitly or implicitly indicate that the embodiment includes at least one of those features. In the description of this invention, the word "multiple" means at least two or more, such as two, three, four, etc., unless otherwise explicitly specified in the embodiments.

[0081] In embodiments of the present invention, the terms "comprising," "including," or any other variations thereof are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element. Furthermore, components, features, and elements with the same names in different embodiments of the present invention may have the same meaning or different meanings, the specific meaning of which must be determined by its interpretation in that specific embodiment or further in conjunction with the context of that specific embodiment.

[0082] Although embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention. Other embodiments of the present invention will readily conceive of by considering the specification and practicing the invention. This application is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein. The specification and embodiments are to be considered exemplary only, and the true scope and spirit of the invention are indicated by the following claims.

Claims

1. A boost circuit based on a sampling capacitor multiplexing boost amplifier, characterized in that, This includes a boost amplifier, sampling capacitor, flying capacitor, feedback resistor, and switching network; The boost amplifier is used to output a boost voltage to the flying capacitor, the sampling capacitor is used to sample the boost voltage output by the boost amplifier, the flying capacitor is used to perform periodic charging and discharging to keep the output voltage of the boost circuit constant, and the feedback resistor is used to perform feedback sampling of the output voltage of the boost circuit. The switch network includes a first switch, a second switch, a third switch, a fourth switch, and a fifth switch. The first switch is located between the flying capacitor and the output node of the boost circuit. This first switch is a single-pole double-throw switch, with its stationary terminal connected to one end of the flying capacitor, its first moving terminal connected to the output terminal of the boost amplifier, and its second moving terminal connected to the output node of the boost circuit. The second switch is located between the flying capacitor and the output terminal of the boost amplifier. This second switch is also a single-pole double-throw switch, with its stationary terminal connected to the second end of the flying capacitor and its first moving terminal connected to the output terminal of the boost amplifier. The second moving terminal is connected to signal ground; the third switch is located between the sampling capacitor and the boost amplifier. The third switch is a single-pole double-throw switch, with its stationary terminal connected to one end of the sampling capacitor, its first moving terminal connected to the reference input terminal of the boost amplifier, its second moving terminal connected to the output terminal of the boost amplifier, and the second terminal of the sampling capacitor grounded; the fourth switch is located between the reference voltage input and the reference input terminal of the boost amplifier, and the fifth switch is located between the feedback resistor and the feedback input terminal of the boost amplifier; the operating mode of the boost circuit is switched through the switch network.

2. The boost circuit based on a sampling capacitor multiplexing boost amplifier according to claim 1, characterized in that, The fourth switch is a single-pole single-throw switch, with one end connected to the reference voltage input and the other end connected to the reference input terminal of the boost amplifier; the fourth switch is further away from the reference input terminal of the boost amplifier relative to the connection node of the third switch. The fifth switch is a single-pole double-throw switch. The stationary terminal is connected to the reference input terminal of the boost amplifier, the first moving terminal is connected to the output terminal of the boost amplifier, and the second moving terminal is connected to the feedback resistor.

3. The boost circuit based on a sampling capacitor multiplexing boost amplifier according to claim 2, characterized in that, The boost circuit has a boost operating mode. In the boost operating mode, the first switch is connected to the flying capacitor and the output node of the boost circuit; the second switch is connected to the output terminal of the boost amplifier and the flying capacitor; the third switch is connected to the output terminal of the boost amplifier and the sampling capacitor; the fourth switch is in the ON state; and the fifth switch is connected to the feedback resistor and the feedback input terminal of the boost amplifier. In boost mode, the boost amplifier dynamically adjusts the boost voltage output by comparing the reference voltage at the reference input terminal with the feedback voltage at the feedback input terminal; the boost voltage is superimposed on the discharge voltage of the flying capacitor to serve as the output voltage of the boost circuit. The boost voltage is also sampled through the sampling capacitor, so that the voltage of the sampling capacitor is maintained at the potential of the boost voltage.

4. A boost circuit based on a sampling capacitor multiplexing boost amplifier according to claim 2, characterized in that, The boost circuit also has a charging mode. In the charging mode, the first switch connects the flying capacitor and the output terminal of the boost amplifier; the second switch connects the flying capacitor and signal ground. The third switch connects the sampling capacitor and the reference input terminal of the boost amplifier; the fourth switch is in the off state; the fifth switch connects the output terminal and the reference input terminal of the boost amplifier. In charging mode, the sampling capacitor inputs the boost voltage sampled in the previous boost mode to the reference input of the boost amplifier. Simultaneously, the boost voltage output by the boost amplifier at the current moment is input through the feedback input, making the boost voltage output by the boost amplifier at the current moment equal to the boost voltage at the previous moment. The boost voltage output at the current moment is used to charge the flying capacitor, so that the voltage of the flying capacitor remains at the potential of the boost voltage at the previous moment, and is superimposed on the boost voltage output by the boost amplifier at the next moment in the next boost mode.

5. A boost circuit based on a sampling capacitor multiplexing boost amplifier, characterized in that, This includes a boost amplifier, sampling capacitor, flying capacitor, feedback resistor, and switching network; The boost amplifier is used to output a boost voltage to the flying capacitor, the sampling capacitor is used to sample the boost voltage output by the boost amplifier, the flying capacitor is used to perform periodic charging and discharging to maintain a constant output voltage of the boost circuit, and the feedback resistor is used to perform feedback sampling of the output voltage of the boost circuit; the sampling capacitor is connected between the output terminal and the feedback input terminal of the boost amplifier. The switch network includes a first switch, a second switch, and a sixth switch. The first switch is located between the flying capacitor and the output node of the boost circuit. The first switch is a single-pole double-throw switch, with its stationary terminal connected to one end of the flying capacitor, its first moving terminal connected to the output terminal of the boost amplifier, and its second moving terminal connected to the output node of the boost circuit. The second switch is located between the flying capacitor and the output terminal of the boost amplifier. The second switch is also a single-pole double-throw switch, with its stationary terminal connected to the second end of the flying capacitor, its first moving terminal connected to the output terminal of the boost amplifier, and its second moving terminal connected to signal ground. The sixth switch is located between the feedback resistor and the feedback input terminal of the boost amplifier, further away from the feedback input terminal of the boost amplifier relative to the connection node of the sampling capacitor. The switch network switches the operating mode of the boost circuit.

6. A boost circuit based on a sampling capacitor multiplexing boost amplifier according to claim 5, characterized in that, The boost circuit has a boost operating mode. In the boost operating mode, the first switch connects the flying capacitor and the output node of the boost circuit; the second switch connects the output terminal of the boost amplifier and the flying capacitor; and the sixth switch is in the ON state. In boost mode, the boost voltage output from the boost amplifier is superimposed on the discharge voltage of the flying capacitor to serve as the output voltage of the boost circuit; the voltage potential of the sampling capacitor is the difference between the boost voltage and the feedback voltage at the feedback input of the boost amplifier.

7. A boost circuit based on a sampling capacitor multiplexing boost amplifier according to claim 5, characterized in that, The boost circuit also has a charging mode. In the charging mode, the first switch connects the flying capacitor and the output terminal of the boost amplifier; the second switch connects the flying capacitor and signal ground. The sixth switch is in the off state; In charging mode, the potential at the feedback input of the boost amplifier is the potential of the reference voltage. The potential at the output of the boost amplifier is fixed to the potential of the boost voltage at the previous moment through the sampling capacitor. At the same time, the boost amplifier charges the flying capacitor, so that the voltage of the flying capacitor is maintained at the potential of the boost voltage at the previous moment, and is superimposed with the boost voltage output of the boost amplifier at the next moment in the boost operation mode.

8. A boost circuit based on a sampling capacitor multiplexing boost amplifier, characterized in that, This includes a boost amplifier, sampling capacitor, flying capacitor, feedback resistor, and switching network; The boost amplifier is used to output a boost voltage to the flying capacitor, the sampling capacitor is used to sample the boost voltage output by the boost amplifier, the flying capacitor is used to perform periodic charging and discharging to keep the output voltage of the boost circuit constant, and the feedback resistor is used to perform feedback sampling of the output voltage of the boost circuit. The switch network includes a first switch, a second switch, and a seventh switch. The first switch is located between the flying capacitor and the output node of the boost circuit. The first switch is a single-pole double-throw switch, with its stationary terminal connected to one end of the flying capacitor, its first moving terminal connected to the output terminal of the boost amplifier, and its second moving terminal connected to the output node of the boost circuit. The second switch is located between the flying capacitor and the output terminal of the boost amplifier. The second switch is also a single-pole double-throw switch, with its stationary terminal connected to the second end of the flying capacitor, its first moving terminal connected to the output terminal of the boost amplifier, and its second moving terminal connected to signal ground. The seventh switch is located between the output stage MOSFET and the current mirror circuit inside the boost amplifier, and is used to control the potential of the boost voltage output by the output stage MOSFET. The sampling capacitor is connected between the gate and source of the output stage MOSFET inside the boost amplifier.

9. A boost circuit based on a sampling capacitor multiplexing boost amplifier according to claim 8, characterized in that, The boost circuit has a boost operating mode. In the boost operating mode, the first switch connects the flying capacitor and the output node of the boost circuit; the second switch connects the output terminal of the boost amplifier and the flying capacitor; and the seventh switch is in the ON state. In boost mode, the boost voltage output from the boost amplifier is superimposed with the discharge voltage of the flying capacitor to serve as the output voltage of the boost circuit; the voltage potential of the sampling capacitor is the potential difference between the gate and source of the MOS transistor in the output stage of the boost amplifier.

10. A boost circuit based on a sampling capacitor multiplexing boost amplifier according to claim 8, characterized in that, The boost circuit also has a charging mode. In the charging mode, the first switch connects the flying capacitor and the output terminal of the boost amplifier; the second switch connects the flying capacitor and signal ground; and the seventh switch is in the off state. In the charging mode, the potential of the gate of the output stage MOS transistor inside the boost amplifier is fixed. The potential of the source of the output stage MOS transistor is fixed to the potential of the boost voltage at the previous moment through the sampling capacitor. At the same time, the boost amplifier charges the flying capacitor so that the voltage of the flying capacitor is maintained at the potential of the boost voltage at the previous moment, and is superimposed with the boost voltage output by the boost amplifier at the next moment in the boost mode.

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