TWI822089B - Switched capacitor voltage converter circuit and switched capacitor voltage conversion method - Google Patents

Abstract

The present invention provides a switched capacitor voltage converter circuit including: a switched capacitor converter and a control circuit; wherein in a charging process of a resonant mode, at least one capacitor is electrically connected to a corresponding inductor in series between a first voltage and a second voltage by switching a plurality of switches via a charging operation signal to form a charging path; in at least one discharging process of the resonant mode, the at least one capacitor is electrically connected to the corresponding inductor in series between the second voltage and a direct current potential by switching the plural switches via at least one discharging operation signal to form a plurality of discharging paths at the same time or alternately; in a switched inductor mode, one end of the at least one inductor is alternately coupled to the first voltage and the direct current potential by switching the plural switches via an inductor operation signal; the control circuit is configured to select to operate in the resonant mode or the switched inductor mode according to the first voltage, so as to maintain the second voltage in a predetermined range.

Description

Switched capacitor voltage conversion circuit and switched capacitor voltage conversion method

The present invention relates to a switched capacitor voltage conversion circuit, and in particular to a switched capacitor voltage conversion circuit and a switched capacitor voltage conversion method that can automatically switch to multiple operating modes.

FIG. 1 shows a conventional resonant switched capacitor voltage converter 10 . This conventional resonant switched capacitive voltage converter 10 has a voltage conversion ratio of input voltage Vin to output voltage Vout of 2:1, and when its switch operates at the resonant frequency and switches to flexible switching with zero current switching/zero voltage switching state, it can provide high-efficiency operation. However, due to its fixed 2-to-1 conversion ratio, its output voltage Vout has a wide range, thus limiting its application to applications with wide input voltage conditions.

In view of this, the present invention proposes an innovative switched capacitor voltage conversion circuit to address the above-mentioned shortcomings of the prior art.

In one aspect, the present invention provides a switched capacitor voltage conversion circuit for converting a first voltage into a second voltage or converting the second voltage into the first voltage. The switched capacitor voltage conversion circuit includes : a switched capacitor converter coupled between the first voltage and the second voltage; and a control circuit for generating a control signal to control the switched capacitor converter, and converting the first voltage to the second voltage or convert the second voltage to the first voltage; wherein the switched capacitor converter includes: at least one capacitor; a plurality of switches coupled to the at least one capacitor; and at least one inductor; wherein the control circuit uses According to the level of the first voltage and with the goal of maintaining the second voltage within a first predetermined range, the ratio between the first voltage and the second voltage is selected, and then the control signal is generated to The first voltage is converted to the second voltage, or the control circuit is used to select the third voltage according to the level of the second voltage with the goal of maintaining the first voltage within a second predetermined range. The ratio between a voltage and the second voltage generates the control signal to convert the second voltage into the first voltage; wherein the control signal includes a charging operation signal and at least one discharging operation signal; wherein, in In a charging process in a resonant operation mode, the charging operation signal is used to control the switching of the plurality of switches, so that the at least one capacitor and the corresponding inductor are connected in series between the first voltage and the second voltage to form a The charging path and resonance operation; wherein, in at least one discharge process of the resonance operation mode, the switching of the plurality of switches is controlled by the discharge operation signal, so that the at least one capacitor and the corresponding inductor are connected in series with the second voltage and Between the DC potentials, a plurality of discharge paths are formed at the same time or in turns and operate in resonance; wherein, in the resonance operation mode, the charging operation signal and the at least one discharging operation signal are respectively switched to a conduction level for a period of conduction. period, and the plurality of conduction periods do not overlap with each other, so that the charging process and the at least one discharging process do not overlap with each other; wherein, in the harmonic In the vibration operation mode, the charging process and the at least one discharging process are repeatedly interleaved with each other to convert the first voltage to the second voltage or the second voltage to the first voltage.

In one embodiment, the control signal further includes an inductor operation signal to control the switching of the plurality of switches, so that the switched capacitor converter operates in an inductor switching mode, so that one end of the at least one inductor is alternately coupled to the first voltage or the DC potential to convert the first voltage to the second voltage and maintain the second voltage within the first predetermined range, or to convert the second voltage to the first voltage, and maintaining the first voltage within the second predetermined range.

In one embodiment, in the resonant operation mode and/or the inductor switching mode, the control circuit decreases the duty cycle of the charging operation signal and/or the discharging operation signal and/or the inductor operation signal so as to When part of the plurality of switches is turned on, the inductor current flowing toward the second voltage is in a first state, and when all of the plurality of switches are not turned on, the inductor current flowing through the corresponding inductor is freewheeling through at least one current. The path continues to flow, thereby causing the inductor current flowing toward the second voltage to be in a second state, so that the corresponding inductor performs inductive power conversion switching between the first state and the second state.

In one embodiment, in the resonant operating mode, the first state is that the inductor current flowing toward the second voltage is a resonant current.

In one embodiment, in the inductor switching mode, the first state is that the inductor current flowing toward the second voltage is a non-resonant current.

In one embodiment, in the inductor switching mode, the first state is that the inductor current flowing toward the second voltage is a triangular wave current.

In one embodiment, the second state is that the inductor current flowing toward the second voltage is a non-resonant current.

In one embodiment, the second state is that the inductor current flowing toward the second voltage is a linear ramp current.

In one embodiment, in the resonant operating mode and/or the inductor switching mode, the control circuit reduces the duty cycle of the charging operation signal and/or the discharging operation signal and/or the inductor operating signal to When the plurality of switches are all non-conductive, the corresponding end of the inductor is conducted to the DC potential through the internal diode (body diode) in at least one switch, thereby causing the voltage to flow toward the second voltage. The inductor current is the linear ramp current.

In one embodiment, the at least one capacitor includes two capacitors, wherein the resonant operating mode includes a two-to-one mode and/or a three-to-one mode; wherein the control circuit selects the The switched capacitor converter operates in the two-to-one mode or the three-to-one mode; wherein, in the two-to-one mode, the control circuit controls the plurality of switches so that a single capacitor is used in the charging process and the discharging process. The charging path and the discharging path are respectively formed corresponding to the corresponding single inductor and operate in resonance; wherein, in the three-to-one mode, the control circuit controls the plurality of switches, so that in the charging process and the discharging process, both Each of the capacitors and the corresponding single inductor respectively form the charging path and the discharging path and operate in resonance.

In one embodiment, the control circuit selects the switched capacitor converter to operate in one of the two-to-one mode, the three-to-one mode and the inductor switching mode according to the first voltage to switch the second The voltage is maintained within the first predetermined range.

In one embodiment, the inductor switching mode includes a second-order inductor switching mode and/or a third-order inductor switching mode, and the inductor operation signal includes a second-order inductor operation signal and/or a third-order inductor operation signal; wherein, In the second-order inductor switching mode, the switching of the plurality of switches is controlled by the second-order inductor operation signal, so that the voltage at the end of the at least one inductor Periodically switching between the first voltage and the DC potential to convert the first voltage to the second voltage or convert the second voltage to the first voltage; wherein, in the third-order inductor switching mode In, the switching of the plurality of switches is controlled by the third-order inductor operation signal, so that the voltage at the end of the at least one inductor periodically switches between the first voltage, one-half of the first voltage and the DC potential. to convert the first voltage to the second voltage or to convert the second voltage to the first voltage.

In one embodiment, the control circuit selects the switched capacitor converter to operate in the two-to-one mode, the three-to-one mode, the second-order inductor switching mode and the third-order inductor switching mode according to the first voltage. One, to maintain the second voltage within the first predetermined range.

In one embodiment, in the two-to-one mode, the first voltage is twice the second voltage; in the three-to-one mode, the first voltage is three times the second voltage.

In one embodiment, the switched capacitor converter includes a series-parallel switched capacitor converter.

In one embodiment, the series-parallel switched capacitor converter includes a 2-to-1 series-parallel switched capacitor converter, a 2-to-1 series-parallel switched capacitor converter, and a 2-to-1 series-parallel switched capacitor converter. One-quarter series-parallel switched capacitor converter (3-to-1 series-parallel switched capacitor converter), one-quarter series-parallel switched capacitor converter (4-to-1 series-parallel switched capacitor converter) or five-quarter A series-parallel switched capacitor converter (5-to-1 series-parallel switched capacitor converter).

In one embodiment, the DC potential is ground potential.

In one embodiment, the control circuit includes: a current sensing circuit for sensing the current flowing through the at least one inductor to generate at least one current sensing signal; and a control signal generating circuit connected to the current sensing signal. The detection circuit is coupled to generate the control signal according to the current sensing signal.

In one embodiment, the control circuit further includes a voltage sensing circuit for sensing the second voltage or the first voltage to generate a voltage sensing signal, wherein the control signal generating circuit switches when the inductor In the mode, the inductor operation signal is further generated according to the voltage sensing signal.

In one embodiment, the at least one capacitor includes N capacitors, wherein the resonant operation mode includes an M to one mode, where N is a natural number greater than or equal to 2, and M is greater than or equal to 2 and less than or equal to N+1 is a natural number; wherein, the control circuit determines the value of M according to the first voltage, and selects the switched capacitor converter to operate in the M to one mode; wherein, in the M to one mode, the control circuit controls The plurality of switches, in the charging process and the discharging process, causes the M-1 capacitors and the corresponding single inductor to respectively form the charging path and the discharging path and operate in resonance.

In another aspect, the present invention provides a switched capacitor voltage conversion method for converting a first voltage of a switched capacitor converter into a second voltage or converting the second voltage into the first voltage, the The switched capacitor converter includes at least one capacitor, a plurality of switches and at least one inductor. The switched capacitor voltage conversion method includes: maintaining the second voltage within a first predetermined range according to the level of the first voltage. The target is to select the ratio between the first voltage and the second voltage, and then generate a control signal to convert the first voltage to the second voltage, or to convert the first voltage to the second voltage according to the level of the second voltage. The first voltage is maintained within a second predetermined range as a goal, and a value between the first voltage and the second voltage is selected. proportion, and then generate the control signal to convert the second voltage to the first voltage; in a charging process of the resonant operation mode, a charging operation signal is used to control the switching of the plurality of switches, so that the at least one capacitor The corresponding inductor is connected in series between the first voltage and the second voltage to form a charging path and operate in resonance; in at least one discharge process of the resonance operation mode, the complex number is controlled by at least one discharge operation signal. The switching of the switch causes the at least one capacitor and the corresponding inductor to be connected in series between the second voltage and a direct current potential, thereby simultaneously forming or taking turns to form a plurality of discharge paths and resonant operation; wherein in the resonant operation mode, the charging The operation signal and the at least one discharging operation signal are respectively switched to a conduction level for a conduction period, and the plurality of conduction periods do not overlap with each other, so that the charging process and the at least one discharging process do not overlap with each other; wherein in the In the resonant operating mode, the charging process and the at least one discharging process are repeatedly interleaved with each other to convert the first voltage to the second voltage or the second voltage to the first voltage.

In one embodiment, the switched capacitive voltage conversion method further includes: in an inductor switching mode, controlling the switching of the plurality of switches through an inductor operation signal, so that one end of the at least one inductor is alternately coupled to the third switch. a voltage or the DC potential to convert the first voltage to the second voltage and maintain the second voltage within the first predetermined range, or to convert the second voltage to the first voltage and The first voltage is maintained within the second predetermined range.

In one embodiment, the switched capacitive voltage conversion method further includes: reducing the charging operation signal and/or the discharging operation signal and/or the inductor operation signal in the resonant operation mode and/or the inductor switching mode. The duty cycle is such that when part of the plurality of switches are turned on, the inductor current flowing toward the second voltage is in a first state, and when all of the plurality of switches are not turned on, the inductor current flowing through the corresponding inductor is The current flows through at least one current freewheeling path The inductor current flowing toward the second voltage is in a second state, so that the corresponding inductor performs inductive power conversion switching between the first state and the second state.

In one embodiment, in the resonant operation mode and/or the inductor switching mode, when the duty cycle of the charge operation signal and/or the discharge operation signal and/or the inductor operation signal is reduced, and the plurality of When the switches are all off, the corresponding end of the inductor is turned on to the DC potential through at least one internal diode (body diode) in the switch, thereby causing the inductor current to flow toward the second voltage. is the linear ramp current.

In one embodiment, the at least one capacitor includes two capacitors, wherein the resonant operating mode includes a two-to-one mode and/or a three-to-one mode; wherein the switching capacitor is selected to switch according to the first voltage. The device operates in the two-to-one mode or the three-to-one mode; wherein, in the two-to-one mode, the charging operation signal and the discharging operation signal control the plurality of switches, so that in the charging process and the discharging process, A single capacitor and a corresponding single inductor respectively form the charging path and the discharging path and operate in resonance; wherein, in the three-to-one mode, the charging operation signal and the discharging operation signal control the plurality of switches, and in the charging In the process and the discharging process, the two capacitors and the corresponding single inductor respectively form the charging path and the discharging path and operate in resonance.

In one embodiment, the step of selecting the switched capacitor converter to operate in the resonant operating mode or the inductive switching mode according to the first voltage includes selecting the switched capacitor converter to operate in the two modes according to the first voltage. Switch to one of the one mode, the three-to-one mode and the inductor switching mode to maintain the second voltage within the first predetermined range.

In one embodiment, the inductor switching mode includes a second-order inductor switching mode and/or a third-order inductor switching mode, and the inductor operation signal includes a second-order inductor operation signal and/or a third-order inductor operation signal; wherein, In the second-order inductor switching mode, the second-order inductor operation signal controls the switching of the plurality of switches, so that the voltage at the end of the at least one inductor periodically switches between the first voltage and the DC potential, so as to switch the The first voltage is converted into the second voltage or the second voltage is converted into the first voltage; wherein, in the third-order inductor switching mode, the switching of the plurality of switches is controlled by the third-order inductor operation signal, so that The voltage at the end of the at least one inductor periodically switches between the first voltage, half of the first voltage and the DC potential to convert the first voltage to the second voltage or to convert the first voltage to the second voltage. The second voltage is converted to the first voltage.

In one embodiment, the step of selecting the switched capacitor converter to operate in the resonant operating mode or the inductive switching mode according to the first voltage includes selecting the switched capacitor converter to operate in the two modes according to the first voltage. One of the first-to-one mode, the three-to-one mode, the second-order inductance switching mode, and the third-order inductance switching mode is used to maintain the second voltage within the first predetermined range.

In one embodiment, the switched capacitive voltage conversion method further includes: sensing the current flowing through the at least one inductor to generate at least one current sensing signal; and generating the charging operation signal according to the current sensing signal, The at least one discharge operation signal and the inductor operation signal.

In one embodiment, the switched capacitor voltage conversion method further includes: sensing the second voltage or the first voltage to generate a voltage sensing signal, and in the inductor switching mode, based on the voltage sensing signal The inductor operation signal is generated.

In one embodiment, the at least one capacitor includes N capacitors, wherein the resonant operation mode includes an M to one mode, where N is a natural number greater than or equal to 2, and M is greater than or equal to 2 and less than or equal to N+1 is a natural number; wherein the value of M is determined according to the first voltage, and the switched capacitor converter is selected to operate in the M to one mode; wherein in the M to one mode, the complex switch is controlled to In the charging process and the discharging process, the M-1 capacitors and the corresponding single inductor respectively form the charging path and the discharging path and operate in resonance.

The advantage of the present invention is that by combining the M to 1 mode and the second-order or third-order inductance switching mode, the output voltage can have a smaller variation range, can provide more operating modes with different voltage conversion ratios, and can achieve resonance. Automatic mode switching control for switching capacitive converters between multiple operating modes.

It will be easier to understand the purpose, technical content, characteristics and achieved effects of the present invention through detailed description of specific embodiments below.

10:Resonant switched capacitive voltage converter

20, 30, 30’, 40, 50, 60, 70: Switching capacitive voltage conversion circuit

201,601,701:Control circuit

202,602,702: Switched Capacitor Converter

2011: Current sensing circuit

2012:Control signal generation circuit

2013: Voltage Sensing Circuit

C1~C4,CV2: capacitor

Cd: current sensing signal

GA: charging operation signal

GB: discharge operation signal

Gb21, Gb22: Second-order inductor operation signal

Gb31, Gb31: third-order inductor operation signal

I1: first current

I2: second current

IC1: capacitor current

IL: inductor current

L: inductance

M: voltage conversion ratio

N: number of capacitors

Q1~Q13: switch

V1: first voltage

V11, V12, V13, V21, V22: voltage

V2: second voltage

Vd: voltage sensing signal

Vds1, Vds6: drain-source voltage

Vin: input voltage

Vout: output voltage

Vth1: first threshold

Vth2: second threshold

Vth3: third threshold

Vth4: fourth threshold

Vth5: fifth threshold

Vth6: sixth threshold

FIG. 1 is a schematic diagram of a conventional resonant switched capacitor voltage converter.

FIG. 2A is a schematic circuit diagram showing a switched capacitor voltage conversion circuit according to an embodiment of the present invention.

FIG. 2B is a schematic diagram showing signal waveforms of related signals of a switched capacitor voltage conversion circuit according to an embodiment of the present invention.

FIG. 2C is a block diagram showing a control circuit of a switched capacitor voltage conversion circuit according to an embodiment of the present invention.

FIG. 3A is a schematic circuit diagram showing a switched capacitor voltage conversion circuit according to another embodiment of the present invention.

FIG. 3B is a schematic diagram showing signal waveforms of related signals of a switched capacitor voltage conversion circuit according to an embodiment of the present invention.

FIG. 3C is a schematic circuit diagram showing a switched capacitor voltage conversion circuit according to yet another embodiment of the present invention.

FIG. 3D is a schematic circuit diagram showing a switched capacitor voltage conversion circuit according to another embodiment of the present invention.

FIG. 4 is a schematic circuit diagram showing a switched capacitor voltage conversion circuit according to yet another embodiment of the present invention.

FIG. 5 is a schematic circuit diagram showing a switched capacitor voltage conversion circuit according to another embodiment of the present invention.

FIG. 6 is a diagram showing operation mode characteristics of a switched capacitor voltage conversion circuit according to an embodiment of the present invention.

FIG. 7 is a diagram showing operation mode characteristics of a switched capacitor voltage conversion circuit according to another embodiment of the present invention.

FIG. 8 is a schematic circuit diagram showing a switched capacitor voltage conversion circuit according to yet another embodiment of the present invention.

FIG. 9 is a schematic circuit diagram showing a switched capacitor voltage conversion circuit according to another embodiment of the present invention.

The diagrams in the present invention are schematic and are mainly intended to represent the coupling relationship between circuits and the relationship between signal waveforms. The circuits, signal waveforms and frequencies are not drawn to scale.

FIG. 2A is a circuit schematic diagram showing a switched capacitor voltage conversion circuit according to an embodiment of the present invention. As shown in FIG. 2A , the switched capacitor voltage conversion circuit 20 is used to convert the first voltage V1 into the second voltage V2 or convert the second voltage V2 into the first voltage V1 . The switched capacitor voltage conversion circuit 20 includes a control circuit 201 and a switched capacitor converter 202 . The switched capacitor converter 202 is coupled between the first voltage V1 and the second voltage V2. The control circuit 201 is used to generate a control signal to control the switched capacitor converter 202 to convert the first voltage V1 into the second voltage V2 or convert the second voltage V2 into the first voltage V1. In this embodiment, the control signal includes a charging operation signal GA and at least one discharging operation signal GB. The switched capacitor converter 202 includes at least one capacitor C1 and C2, a plurality of switches Q1˜Q7, and at least one inductor L. The plurality of switches Q1 ~ Q7 are coupled to at least one capacitor C1 and C2.

The control circuit 201 is used to select the ratio between the first voltage V1 and the second voltage V2 according to the level of the first voltage V1 and with the goal of maintaining the second voltage V2 within a first predetermined range, and then generate a control signal. , to convert the first voltage V1 into the second voltage V2; or the control circuit 201 is used to select the first voltage V1 according to the level of the second voltage V2 with the goal of maintaining the first voltage V1 within the second predetermined range. The ratio between a voltage V1 and a second voltage V2 generates a control signal to convert the second voltage V2 into the first voltage V1.

In the charging process of the resonant operation mode, the charging operation signal GA controls the switching of the plurality of switches Q1 ~ Q7, so that at least one capacitor C1 and C2 and the corresponding inductor L are connected in series. between the first voltage V1 and the second voltage V2 to form a charging path and operate in resonance. In at least one discharging process in the resonant operating mode, the discharging operation signal GB controls the switching of the plurality of switches Q1 to Q7, so that at least one capacitor C1 and C2 and the corresponding inductor L are connected in series to the second voltage V2 and the DC potential (at In this embodiment, the DC potential is between the ground potential and the ground potential, and a plurality of discharge paths are formed simultaneously or alternately and operate in resonance. In the resonant operating mode, the charging process and the at least one discharging process are repeatedly interleaved with each other to convert the first voltage V1 to the second voltage V2 or the second voltage V2 to the first voltage V1.

Please refer to FIG. 2A again. In the resonant operation mode, the control circuit 201 can adjust the duty cycle of the charging operation signal GA and/or the discharging operation signal GB to operate on some complex switches (such as switches Q1~Q3 or switches Q4~Q7). ) is turned on, causing the inductor current IL flowing toward the second voltage V2 to be in the first state, and when a plurality of switches (such as switches Q1 ~ Q7) are not turned on, causing the inductor current IL flowing through the corresponding inductor L to pass through at least one The current freewheeling path in the switch (such as switches Q3 and Q7), such as but not limited to the conduction of the internal diode (body diode), freewheels, thereby causing the inductor current IL flowing towards the second voltage V2 to be in the second state. , so that the corresponding inductor L performs inductive power conversion switching between the first state and the second state.

In one embodiment, in the resonant operation mode, the inductor current IL flowing toward the second voltage V2 in the first state is the resonant current. In one embodiment, the second state is that the inductor current IL flowing toward the second voltage V2 is a non-resonant current. In a preferred embodiment, the second state is that the inductor current IL flowing toward the second voltage V2 is a linear ramp current. For example, in the resonant operation mode and/or the inductance switching mode, the control circuit 201 reduces the duty cycle of the charging operation signal GA and/or the discharging operation signal GB so that none of the plurality of switches (such as switches Q1~Q7) conduction When , one end of the corresponding inductor L is turned on to the DC potential through the internal diode (body diode) in at least one switch (such as switches Q3 and Q7), thereby causing the inductor current IL flowing toward the second voltage V2 to be Linear ramp current.

Referring again to FIG. 2A , the switched capacitor converter 202 can further operate in the inductor switching mode. In the inductor switching mode, the control signal further includes an inductor operation signal to control the switching of multiple switches (such as switches Q1~Q7). The inductor operation signal controls the switching of the multiple switches so that one end of the inductor L (inductor L in Figure 2A) The left end) is alternately coupled to the first voltage V1 or the DC potential (in this embodiment, the ground potential) to convert the first voltage V1 into the second voltage V2 and maintain the second voltage V2 within the first predetermined range. , or convert the second voltage V2 to the first voltage V1, and maintain the first voltage V1 within the second predetermined range.

FIG. 2B is a schematic diagram showing signal waveforms of related signals of a switched capacitor voltage conversion circuit according to an embodiment of the present invention. The second voltage V2, the second current I2, the inductor current IL, the capacitor current IC1, the drain-source voltage Vds1 of the switch Q1, the drain-source voltage Vds6 of the switch Q6, the charging operation signal GA and the discharging operation signal GB are as shown in Figure 2B Show. As shown in FIG. 2B , in the resonant operation mode, the charging operation signal GA and at least one discharging operation signal GB are respectively switched to a conduction level for a conduction period, and the plurality of conduction periods do not overlap with each other, so that the charging process is consistent with at least A discharge program does not overlap with each other.

FIG. 2C is a block diagram showing a control circuit of a switched capacitor voltage conversion circuit according to an embodiment of the present invention. Please refer to FIG. 2C and FIG. 2A simultaneously. The control circuit 201 includes a current sensing circuit 2011, a control signal generating circuit 2012 and a voltage sensing circuit 2013. The current sensing circuit 2011 is used to sense the current flowing through at least one inductor L to generate There is one less current sensing signal Cd, and the control signal generating circuit 2012 is coupled to the current sensing circuit 2011 for generating control signals such as a charging operation signal GA and a discharging operation signal GB according to the current sensing signal Cd. The voltage sensing circuit 2013 is used to sense the second voltage V2 to generate a voltage sensing signal Vd. The control signal generation circuit 2012, in the inductor switching mode, further generates inductor operation signals such as second-order inductor operation signals Gb21 and Gb22 (to be described in detail later) and/or third-order inductor operation signals Gb31 and Gb32 according to the voltage sensing signal Vd. (Details will be discussed later).

FIG. 3A is a schematic circuit diagram showing a switched capacitor voltage conversion circuit according to another embodiment of the present invention. The embodiment of FIG. 3A is similar to the embodiment of FIG. 2A . The difference is that in this embodiment, the switch Q5 is always on, and the switches Q3 and Q7 are always not on, so that the switched capacitor converter 202 enters the two-to-one mode. That is, the ratio of the first voltage V1 to the second voltage V2 is 2:1. In the charging process of the resonant operation mode, the charging operation signal GA controls the switching of the plurality of switches Q1, Q2, Q4, and Q6, so that at least one capacitor C1 and the corresponding inductor L are connected in series between the first voltage V1 and the second voltage V2. time to form a charging path and operate resonantly. In at least one discharging process in the resonant operation mode, the discharging operation signal GB controls the switching of the plurality of switches Q1, Q2, Q4, and Q6, so that at least one capacitor C1 and the corresponding inductor L are connected in series between the second voltage V2 and the DC potential. time to form a discharge path and operate resonantly. The way in which the inductor current freewheels is similar to the embodiment of FIG. 2A , but the difference is that in this embodiment, the freewheeling current is conducted through the conduction of the internal diodes of switches Q2 and Q6 . In one embodiment, the control circuit 201 selects the switched capacitor converter 202 to operate in the two-to-one mode or the three-to-one mode according to the first voltage V1 to maintain the second voltage V2 within the first predetermined range.

FIG. 3B is a schematic diagram showing signal waveforms of related signals of a switched capacitor voltage conversion circuit according to an embodiment of the present invention. The second voltage V2, the second current I2, the electric The sense current IL, the capacitor current IC1, the drain-source voltage Vds1 of the switch Q1, the drain-source voltage Vds6 of the switch Q6, the charging operation signal GA and the discharging operation signal GB are shown in Figure 3B.

FIG. 3C is a schematic circuit diagram showing a switched capacitor voltage conversion circuit according to yet another embodiment of the present invention. FIG. 3D is a schematic circuit diagram showing a switched capacitor voltage conversion circuit according to another embodiment of the present invention. The embodiments of FIGS. 3C and 3D are similar to the embodiment of FIG. 3A , except that in this embodiment, the control signal further includes an inductor operation signal, and the inductor operation signal includes third-order inductor operation signals Gb31 and Gb32 . In the third-order inductor switching mode, the third-order inductor operating signals Gb31 and Gb32 control the switching of multiple switches (such as switches Q1, Q2, Q4, Q6), and in the inductor switching mode, the switches Q3 and Q7 are always non-conductive. The voltage at one end of at least one inductor L is periodically switched between the first voltage V1, half of the first voltage V1, and the DC potential (ground potential in this embodiment), so as to change the first voltage V1 converted to the second voltage V2.

Please refer to FIG. 3C again. In the inductor switching mode, the control circuit 201 can adjust the duty cycle of the inductor operation signals Gb31 and Gb32 so that when some of the complex switches (such as switches Q1 and Q2 or switches Q4 and Q6) are turned on, the The inductor current IL flowing toward the second voltage V2 is in the first state, and when the plurality of switches (such as switches Q1, Q2, Q4, Q6) are all non-conductive, the inductor current IL flowing through the corresponding inductor L passes through at least one switch. (For example, switches Q2 and Q6) The internal diodes (body diodes) in the switches Q2 and Q6 are conductive and freewheeling, thereby causing the inductor current IL flowing toward the second voltage V2 to be in the second state, so that the corresponding inductor L is in the first state. Perform inductive power conversion switching between the second state and the second state. In one embodiment, the first state is that the inductor current IL flowing toward the second voltage V2 is a non-resonant current. In a preferred embodiment, the first state is towards the second voltage V2 The flowing inductor current IL is a triangular wave current. In one embodiment, the second state is that the inductor current IL flowing toward the second voltage V2 is a non-resonant current. In a preferred embodiment, the second state is that the inductor current IL flowing toward the second voltage V2 is a linear ramp current.

For example, when the second voltage V2 is between the first voltage V1 and one-half of the first voltage V1, as shown in FIG. 3C , the complex switches Q1, Q2, The switching of Q4 and Q6 causes at least one capacitor C1 and the corresponding inductor L to be connected in series between the second voltage V2 and the DC potential. As shown in Figure 3D, the third-order inductor operation signal Gb31 is then used to control the plurality of switches Q1 and Q2. The switching of Q4 and Q6 causes one end of the inductor L to be coupled to the first voltage V1, thereby causing the voltage at one end of the inductor L to periodically switch between the first voltage V1 and one-half of the first voltage V1. . In another embodiment, when the second voltage V2 is between 0 and half of the first voltage V1, as shown in FIG. 3C , the plurality of switches Q1, Q2, The switching of Q4 and Q6 causes at least one capacitor C1 and the corresponding inductor L to be connected in series between the first voltage V1 and the second voltage V2, and as shown in Figure 3D, the third-order inductor operation signal Gb32 is then used to control the plurality of switches Q1 , Q2, Q4, and Q6 switch, one end of the inductor L is coupled to the DC potential (in this embodiment, the ground potential), thereby causing the voltage at one end of the inductor L to periodically switch between 0 and the first voltage V1 between one-half. The method of freewheeling of the inductor current in Figure 3D is similar to the embodiment of Figure 3C. Please refer to the relevant description of Figure 3C.

FIG. 4 is a schematic circuit diagram showing a switched capacitor voltage conversion circuit according to yet another embodiment of the present invention. This embodiment is similar to the embodiment of FIG. 2A, except that the switches Q2, Q5 and Q6 are always off. In this embodiment, the control signal further includes second-order inductor operation signals Gb21 and Gb22. In the second-order inductor switching mode (also called inductor switching switching mode), the second-order inductor operation signals Gb21 and Gb22 control the switching of the plurality of switches Q1, Q3, Q4, and Q7, so that one end of at least one inductor L is alternately (periodically) coupled to the first voltage V1 or the direct current. bit to convert the first voltage V1 into the second voltage V2. In one embodiment, the control circuit 201 selects the switched capacitor converter 202 to operate in one of the two-to-one mode, the three-to-one mode, the second-order inductance switching mode, and the third-order inductance switching mode according to the first voltage V1, so as to The second voltage V2 is maintained within the first predetermined range. In another embodiment, the control circuit 201 selects the switched capacitor converter 202 to operate in one of the two-to-one mode, the three-to-one mode, and the inductor switching mode according to the first voltage V1 to convert the second voltage V2 maintained within the first predetermined range. The method of freewheeling of the inductor current in this embodiment is similar to the embodiment of Figure 3C. Please refer to the relevant description of Figure 3C. The difference is that in this embodiment, the freewheeling of the current is through the conduction of the internal diodes of switches Q3 and Q7. .

FIG. 5 is a schematic circuit diagram showing a switched capacitor voltage conversion circuit according to another embodiment of the present invention. This embodiment is similar to the embodiment of Figure 4. Please refer to the relevant description of Figure 4. The difference is that the switches Q1 and Q6 are always on, and the second-order inductor operation signals Gb21 and Gb22 only control the switching of the plurality of switches Q4, Q3 and Q7. , one end of at least one inductor L is alternately (periodically) coupled to the first voltage V1 or a DC potential, and the capacitor C1 can be used as an input capacitor. The method of freewheeling of the inductor current in this embodiment is similar to the embodiment of FIG. 4 , please refer to the relevant description of FIG. 4 .

FIG. 6 is a diagram showing operation mode characteristics of a switched capacitor voltage conversion circuit according to an embodiment of the present invention. Please refer to FIGS. 6, 2A and 3A at the same time. The control circuit 201 maintains the second voltage V2 within the first predetermined range (voltage between V21 and voltage V22), and the switched capacitor converter 202 is selected to operate in a two-to-one mode or a three-to-one mode to maintain the second voltage V2 within a first predetermined range, such as between the voltage V21 and the voltage V22. between. As shown in FIG. 6 , the control circuit 201 switches the operating mode in a hysteretic manner. When the first voltage V1 is greater than the first threshold Vth1 , the control circuit 201 causes the switched capacitor converter 202 to operate in the three-to-one mode. When the first voltage V1 is less than the second threshold Vth2, the control circuit 201 causes the switched capacitor converter 202 to operate in the 2-to-1 mode.

FIG. 7 is a diagram showing operation mode characteristics of a switched capacitor voltage conversion circuit according to another embodiment of the present invention. Please refer to Figures 7, 2A, 3A, 3C, 3D, 4 and 5 at the same time. The control circuit 201 selects the switched capacitor converter 202 to operate in the two-to-one mode, the three-to-one mode, and the second-order inductor according to the magnitude of the first voltage V1. One of the switching mode and the third-order inductor switching mode is used to maintain the second voltage V2 within a first predetermined range, such as between the voltage V21 and the voltage V22. As shown in FIG. 7 , when the first voltage V1 is greater than the first threshold Vth1 , the control circuit 201 causes the switched capacitor converter 202 to operate in the second-order inductor switching mode or the third-order inductor switching mode. When the first voltage V1 is less than the second threshold Vth2 and greater than the third threshold Vth3, the control circuit 201 causes the switched capacitor converter 202 to operate in the three-to-one mode. When the first voltage V1 is less than the fourth threshold Vth4 and greater than the fifth threshold Vth5, the control circuit 201 causes the switched capacitor converter 202 to operate in the 2-to-1 mode. When the first voltage V1 is less than the sixth threshold Vth6, the control circuit 201 causes the switched capacitor converter 202 to operate in the second-order inductor switching mode or the third-order inductor switching mode.

FIG. 8 is a schematic circuit diagram showing a switched capacitor voltage conversion circuit according to yet another embodiment of the present invention. As shown in Figure 8, the switched capacitor voltage conversion circuit of the present invention The switched capacitor converter 602 of 60 includes capacitors C1 to C3, switches Q1 to Q10, and an inductor L. The switches Q1-Q3 are connected in series with the corresponding capacitors C1-C3 respectively, and the switch Q4 is connected in series with the inductor L.

The switches Q1-Q10 can switch the electrical connection relationship between the corresponding capacitors C1-C3 and the inductor L according to the corresponding operation signal. During the charging process, according to the charging operation signal GA, the switches Q1-Q4 are turned on, and the switches Q5-Q10 are turned off, so that the capacitors C1-C3 are connected in series with each other and the inductor L is connected in series with the first voltage V1 and the second voltage V2. to form a charging path. In the discharging process, according to the discharging operation signal GB, the switches Q5-Q10 are turned on, and the switches Q1-Q4 are turned off, so that the capacitors C1~C3 are connected in parallel with each other and the inductor L is connected in series between the second voltage V2 and the ground potential to form Complex discharge paths. It should be noted that the above-mentioned charging process and the above-mentioned discharging process are repeatedly and staggered in different time periods, rather than simultaneously, to convert the first voltage V1 to the second voltage V2 or to convert the second voltage V2 to the first voltage V2. Voltage V1. In this embodiment, the DC bias voltage of each capacitor C1 ~ C3 is the second voltage V2. Therefore, the capacitor C1 ~ C3 in this embodiment needs to withstand a lower rated voltage, so a smaller capacitor can be used.

The control circuit 601 and operation method of this embodiment can be implemented similarly to the control circuit structure and operation method of Figures 2A, 2C, 3A, 3C, 3D, 4 and 5. Please refer to Figures 2A, 2C, 3A, 3C, 3D. , 4 and 5 detailed description. The way of freewheeling of the inductor current is similar to Figure 2A if the operation is in the four-to-one mode, similar to Figure 3A if the operation is in the three-to-one mode or the two-to-one mode, and similar to Figure 3A if the operation is in the third-order inductor switching mode. Figures 3C and 3D, if the operation is in the second-order inductance switching mode, are similar to Figures 4 and 5. Please refer to the detailed descriptions of Figures 2A, 3A, 3C, 3D, 4 and 5 respectively.

FIG. 9 is a schematic circuit diagram showing a switched capacitor voltage conversion circuit according to another embodiment of the present invention. As shown in Figure 9, the switched capacitor voltage conversion circuit of the present invention The switched capacitor converter 702 of 70 includes capacitors C1 to C4, switches Q1 to Q13, and an inductor L. The switches Q1-Q4 are connected in series with the corresponding capacitors C1-C4 respectively, and the switch Q5 is connected in series with the inductor L.

The switches Q1-Q13 can switch the electrical connection relationship between the corresponding capacitors C1-C4 and the inductor L according to the corresponding operation signal. During the charging process, according to the charging operation signal GA, the switches Q1-Q5 are turned on, and the switches Q6-Q13 are turned off, so that the capacitors C1-C4 are connected in series with each other and the inductor L is connected in series with the first voltage V1 and the second voltage V2. to form a charging path. In the discharging process, according to the discharging operation signal GB, the switches Q6-Q13 are turned on, and the switches Q1-Q5 are turned off, so that the capacitors C1~C4 are connected in parallel with each other and the inductor L is connected in series between the second voltage V2 and the ground potential to form Complex discharge paths. It should be noted that the above-mentioned charging process and the above-mentioned discharging process are repeatedly and staggered in different time periods, rather than simultaneously, to convert the first voltage V1 to the second voltage V2 or to convert the second voltage V2 to the first voltage V2. Voltage V1. In this embodiment, the DC bias voltage of each capacitor C1 ~ C4 is the second voltage V2. Therefore, the capacitor C1 ~ C4 in this embodiment needs to withstand a lower rated voltage, so a smaller capacitor can be used.

The control circuit 701 and operation method of this embodiment can be implemented similarly to the control circuit structure and operation method of Figures 2A, 2C, 3A, 3C, 3D, 4 and 5. Please refer to Figures 2A, 2C, 3A, 3C, 3D. , 4 and 5 detailed description. If the inductor current is operated in the five-turn-to-one mode, the freewheeling method is similar to Figure 2A. If the operation is in the four-turn-to-one mode, the three-turn-to-one mode, or the two-to-one mode, it is similar to Figure 3A. If the operation is in the third-order inductor The switching mode is similar to Figures 3C and 3D. If the operation is the second-order inductor switching mode, it is similar to Figures 4 and 5. Please refer to the detailed descriptions of Figures 2A, 3A, 3C, 3D, 4 and 5 respectively.

As mentioned above, the present invention provides a switched capacitor voltage conversion circuit, which can make the second voltage (or output voltage) have a higher value by combining the M-to-1 mode and the second-order or third-order inductor switching mode and freewheeling the inductor current. Small variation range, can provide different voltage conversion There are more operating modes of the conversion ratio and automatic mode conversion control between multiple operating modes of the resonant switching capacitive converter can be achieved. It is worth noting that from the above embodiments such as FIG. 2A, FIG. 3A, FIG. 8 and FIG. 9, the relationship between the number of capacitors N included in the switched capacitor voltage conversion circuit and the voltage conversion ratio M can be summarized, where N is greater than A natural number equal to 2, and M is a natural number greater than or equal to 2 and less than or equal to N+1. For example, the switched capacitor voltage conversion circuit of Figure 9 includes four capacitors, which can include a five-to-one mode, a four-to-one mode, a three-to-one mode, or a two-to-one mode. For another example, the switched capacitor of Figure 2 The voltage conversion circuit contains 2 capacitors, which can include a three-to-one mode or a two-to-one mode.

In the embodiments described above, the circuit for converting the first voltage V1 into the second voltage V2 is also applicable to converting the second voltage V2 into the first voltage V1. The control circuit selects the ratio between the first voltage V1 and the second voltage V2 according to the level of the second voltage V2 and aims to maintain the first voltage V1 within the second predetermined range, and then generates a control signal to maintain the first voltage V1 within the second predetermined range. The second voltage V2 is converted into the first voltage V1. Among them, the control circuit 201 selects to operate the switched capacitor converter 202 in one of the two-to-one mode, the three-to-one mode and the inductance switching mode according to the first voltage V1 to maintain the second voltage V2 within the first predetermined range. The same circuit can also operate as the control circuit 201 selects the switched capacitor converter 202 to operate in one of the one-to-two mode, the one-to-three mode and the inductance switching mode according to the second voltage V2, so as to convert the first voltage V1 remains within the second predetermined range.

The present invention has been described above with reference to the preferred embodiments. However, the above description is only to make it easy for those familiar with the art to understand the content of the present invention, and is not intended to limit the broadest scope of rights of the present invention. The various embodiments described are not limited to stand-alone applications; For combined application, for example, two or more embodiments can be used in combination, and some components in one embodiment can also be used to replace corresponding components in another embodiment. In addition, under the same spirit of the present invention, those skilled in the art can think of various equivalent changes and various combinations. For example, the present invention refers to "processing or computing according to a certain signal or generating a certain output result", which is not limited to Depending on the signal itself, it also includes performing voltage-to-current conversion, current-to-voltage conversion, and/or ratio conversion on the signal when necessary, and then processing or calculating the converted signal to produce an output result. It can be seen from this that under the same spirit of the present invention, those skilled in the art can think of various equivalent changes and various combinations. There are many combinations, and they are not listed here. Accordingly, the scope of the present invention is intended to cover the above and all other equivalent changes.

20: Switching capacitive voltage conversion circuit

201:Control circuit

202: Switched Capacitor Converter

C1, C2, CV2: capacitor

GA: charging operation signal

GB: discharge operation signal

I1: first current

I2: second current

IC1: capacitor current

IL: inductor current

L: inductance

Q1~Q7: switch

V1: first voltage

V2: second voltage

Vds1, Vds6: drain-source voltage

Claims (24)

A switched capacitor voltage conversion circuit is used to convert a first voltage into a second voltage or the second voltage into the first voltage. The switched capacitor voltage conversion circuit includes: a switched capacitor converter, a coupling connected between the first voltage and the second voltage; and a control circuit for generating a control signal to control the switched capacitor converter to convert the first voltage to the second voltage or to convert the second voltage to the second voltage. The voltage is converted to the first voltage; wherein the switched capacitor converter includes: at least one capacitor; a plurality of switches coupled to the at least one capacitor; and at least one inductor; wherein the control circuit is used to control the voltage according to the position of the first voltage. standards, and with the goal of maintaining the second voltage within a first predetermined range, select the ratio between the first voltage and the second voltage, and then generate the control signal to convert the first voltage to The second voltage, or the control circuit is used to select a value between the first voltage and the second voltage according to the level of the second voltage and with the goal of maintaining the first voltage within a second predetermined range. proportion, and then generate the control signal to convert the second voltage to the first voltage; wherein the control signal includes a charging operation signal and at least one discharging operation signal; wherein, a charging process in a resonance operation mode In, the charging operation signal is used to control the switching of the plurality of switches, so that the at least one capacitor and the corresponding inductor are connected in series between the first voltage and the second voltage to form a charging path and operate in resonance; Wherein, in at least one discharge process of the resonant operation mode, the switching of the plurality of switches is controlled by the discharge operation signal, so that the at least one capacitor and the corresponding inductor are connected in series between the second voltage and the direct current potential, A plurality of discharge paths are formed at the same time or in turns and operate in resonance; wherein, in the resonance operation mode, the charging operation signal and the at least one discharge operation signal are respectively switched to a conduction level for a conduction period, and the plurality of segments The conduction periods do not overlap with each other, so that the charging process and the at least one discharging process do not overlap with each other; wherein, in the resonant operating mode, the charging process and the at least one discharging process are repeatedly staggered with each other to sequence the first The voltage is converted to the second voltage or the second voltage is converted to the first voltage; wherein the at least one capacitor includes N capacitors, wherein the resonant operation mode includes an M-to-A mode, where N is greater than or equal to 2 is a natural number, and M is a natural number greater than or equal to 2 and less than or equal to N+1; wherein, the control circuit determines the value of M according to the first voltage, and selects the switched capacitor converter to operate when M turns to a mode; wherein, in the M to 1 mode, the control circuit controls the plurality of switches, in the charging process and the discharging process, so that M-1 capacitors and the corresponding single inductor respectively form the charging path and the This discharge path operates resonantly. The switched capacitor voltage conversion circuit of claim 1, wherein the control signal further includes an inductor operation signal to control the switching of the plurality of switches, so that the switched capacitor converter operates in an inductor switching mode, so that at least One end of an inductor is alternately coupled to the first voltage or the DC potential to convert the first voltage to the second voltage and maintain the second voltage within the first predetermined range, or to convert the first voltage to the second voltage. The two voltages are converted into the first voltage, and the first voltage is maintained within the second predetermined range. The switched capacitor voltage conversion circuit as described in claim 2, wherein in the resonant operation mode and/or the inductor switching mode, the control circuit lowers the charging operation signal and/or the discharging operation signal and/or the inductor. The duty cycle of the operation signal is such that when part of the plurality of switches are turned on, the inductor current flowing toward the second voltage is in a first state, and when all of the plurality of switches are not turned on, the inductor current flowing through the corresponding inductor is in a first state. The inductor current freewheels through at least one current freewheeling path, thereby causing the inductor current flowing toward the second voltage to be in a second state, so that the corresponding inductor flows between the first state and the second state. Inductive power conversion switching. The switched capacitor voltage conversion circuit of claim 1, wherein the at least one capacitor includes two of the capacitors, and the resonant operation mode includes a two-to-one mode and/or a three-to-one mode; wherein, the control circuit The switched capacitor converter is selected to operate in the two-to-one mode or the three-to-one mode according to the first voltage; wherein, in the two-to-one mode, the control circuit controls the plurality of switches, during the charging process and In the discharging process, a single capacitor and a corresponding single inductor respectively form the charging path and the discharging path and operate in resonance; wherein, in the three-to-one mode, the control circuit controls the plurality of switches, and during the charging In the process and the discharging process, the two capacitors and the corresponding single inductor respectively form the charging path and the discharging path and operate in resonance; wherein in the two-to-one mode, the first voltage is the second voltage twice; wherein in the three-to-one mode, the first voltage is three times the second voltage. The switched capacitor voltage conversion circuit of claim 4, wherein the control circuit selects the switched capacitor converter to operate in the two-to-one mode, the three-to-one mode according to the first voltage. mode and the inductor switching mode to maintain the second voltage within the first predetermined range. The switched capacitor voltage conversion circuit of claim 2, wherein the inductor switching mode includes a second-order inductor switching mode and/or a third-order inductor switching mode, and the inductor operation signal includes a second-order inductor operation signal and/or A third-order inductor operation signal; wherein, in the second-order inductor switching mode, the second-order inductor operation signal controls the switching of the plurality of switches, so that the voltage at the end of the at least one inductor periodically switches to the first voltage and the DC potential to convert the first voltage to the second voltage or convert the second voltage to the first voltage; wherein, in the third-order inductor switching mode, the third-order inductor operates The signal controls the switching of the plurality of switches so that the voltage at the end of the at least one inductor periodically switches between the first voltage, one-half of the first voltage and the DC potential, so as to change the first voltage Convert to the second voltage or convert the second voltage to the first voltage. The switched capacitor voltage conversion circuit of claim 6, wherein the control circuit selects the switched capacitor converter to operate in the two-to-one mode, the three-to-one mode, and the second-order inductance switching mode according to the first voltage. and one of the three-stage inductance switching modes to maintain the second voltage within the first predetermined range. The switched capacitor voltage conversion circuit of claim 1, wherein the switched capacitor converter includes a series-parallel switched capacitor converter. The switched capacitor voltage conversion circuit as described in claim 8, wherein the series-parallel switched capacitor converter (series-parallel switched capacitor converter) includes a half series-parallel switched capacitor converter. 2-to-1 series-parallel switched capacitor converter, 3-to-1 series-parallel switched capacitor converter, 1/4 series-parallel switched capacitor converter Parallel switched capacitor converter (4-to-1 series-parallel switched capacitor converter) or fifth series-parallel switched capacitor converter (5-to-1 series-parallel switched capacitor converter). The switched capacitor voltage conversion circuit of claim 1, wherein the DC potential is ground potential. The switched capacitor voltage conversion circuit of claim 1, wherein the control circuit includes: a current sensing circuit for sensing the current flowing through the at least one inductor to generate at least one current sensing signal; and a A control signal generating circuit is coupled to the current sensing circuit and used to generate the control signal according to the current sensing signal. The switched capacitor voltage conversion circuit of claim 11, wherein the control circuit further includes a voltage sensing circuit for sensing the second voltage or the first voltage to generate a voltage sensing signal, wherein the The control signal generating circuit further generates the inductor operation signal according to the voltage sensing signal in the inductor switching mode. A switched capacitor voltage conversion method for converting a first voltage of a switched capacitor converter into a second voltage or converting the second voltage into the first voltage. The switched capacitor converter includes at least one capacitor, A plurality of switches and at least one inductor, the switched capacitive voltage conversion method includes: According to the level of the first voltage and with the goal of maintaining the second voltage within a first predetermined range, the ratio between the first voltage and the second voltage is selected to generate a control signal to The first voltage is converted to the second voltage, or the first voltage and the second voltage are selected according to the level of the second voltage with the goal of maintaining the first voltage within a second predetermined range. The ratio between the voltages, and then generates the control signal to convert the second voltage to the first voltage; in a charging process in a resonant operation mode, a charging operation signal is used to control the switching of the plurality of switches, so that the At least one capacitor and the corresponding inductor are connected in series between the first voltage and the second voltage to form a charging path and operate in resonance; in at least one discharge process of the resonance operation mode, through at least one discharge operation signal Control the switching of the plurality of switches so that the at least one capacitor and the corresponding inductor are connected in series between the second voltage and a direct current potential to simultaneously form or alternately form a plurality of discharge paths and operate in resonance; wherein, in the resonance operation mode , the charging operation signal and the at least one discharging operation signal are respectively switched to a conduction level for a conduction period, and the plurality of conduction periods do not overlap with each other, so that the charging process and the at least one discharging process do not overlap with each other. ; wherein in the resonant operating mode, the charging process and the at least one discharging process are repeatedly staggered with each other to convert the first voltage to the second voltage or to convert the second voltage to the first voltage; wherein , the at least one capacitor includes N capacitors, wherein the resonant operation mode includes an M to one mode, where N is a natural number greater than or equal to 2, and M is a natural number greater than or equal to 2 and less than or equal to N+1; wherein , determine the value of M according to the first voltage, and select the switched capacitor converter to operate in the M to one mode; Wherein, in the M to 1 mode, the plurality of switches are controlled, in the charging process and the discharging process, so that M-1 capacitors and the corresponding single inductor respectively form the charging path and the discharging path and resonate. operate. The switched capacitive voltage conversion method as described in claim 13 further includes: in an inductor switching mode, controlling the switching of the plurality of switches by an inductor operation signal, so that one end of the at least one inductor is alternately coupled to the the first voltage or the DC potential to convert the first voltage to the second voltage and maintain the second voltage within the first predetermined range, or convert the second voltage to the first voltage, and Maintain the first voltage within the second predetermined range. The switched capacitive voltage conversion method described in claim 14 further includes: reducing the charging operation signal and/or the discharging operation signal and/or the inductor operation in the resonant operation mode and/or the inductor switching mode. The duty cycle of the signal is such that when part of the plurality of switches are turned on, the inductor current flowing toward the second voltage is in a first state, and when all of the plurality of switches are not turned on, the inductor current flowing through the corresponding inductor is in a first state. The inductor current freewheels through at least one current freewheeling path, thereby causing the inductor current flowing toward the second voltage to be in a second state, so that the corresponding inductor conducts inductance between the first state and the second state. type power conversion switching. The switched capacitive voltage conversion method of claim 13, wherein the at least one capacitor includes two of the capacitors, and the resonant operation mode includes a two-to-one mode and/or a three-to-one mode; wherein, according to the first A voltage is selected to cause the switched capacitor converter to operate in the two-to-one mode or the three-to-one mode; wherein, in the two-to-one mode, the charging operation signal and the discharging operation signal control the plurality of switches, and in the two-to-one mode In the charging process and the discharging process, the single capacitor and the corresponding single inductor respectively form the charging path and the discharging path and operate in resonance; Among them, in the three-to-one mode, the charging operation signal and the discharging operation signal control the plurality of switches, so that in the charging process and the discharging process, the two capacitors and the corresponding single inductor respectively form the charging process. The path operates in resonance with the discharge path; in the two-to-one mode, the first voltage is twice the second voltage; in the three-to-one mode, the first voltage is twice the second voltage three times. The switched capacitor voltage conversion method of claim 16, wherein the step of selecting the switched capacitor converter to operate in the resonant operating mode or the inductive switching mode according to the first voltage includes selecting to operate the switched capacitor converter in the resonant operating mode or the inductive switching mode according to the first voltage. The switched capacitor converter operates in one of the two-to-one mode, the three-to-one mode and the inductance switching mode to maintain the second voltage within the first predetermined range. The switched capacitor voltage conversion method as described in claim 14, wherein the inductor switching mode includes a second-order inductor switching mode and/or a third-order inductor switching mode, and the inductor operation signal includes a second-order inductor operation signal and/or A third-order inductor operation signal; wherein, in the second-order inductor switching mode, the second-order inductor operation signal controls the switching of the plurality of switches, so that the voltage at the end of the at least one inductor periodically switches to the first voltage and the DC potential to convert the first voltage to the second voltage or convert the second voltage to the first voltage; wherein, in the third-order inductor switching mode, the third-order inductor operates The signal controls the switching of the plurality of switches so that the voltage at the end of the at least one inductor periodically switches between the first voltage, one-half of the first voltage and the DC potential, so as to change the first voltage Convert to the second voltage or convert the second voltage to the first voltage. The switched capacitor voltage conversion method of claim 18, wherein the switched capacitor converter is selected to operate in the resonant operating mode or the inductive switching mode according to the first voltage. The step includes selecting the switched capacitor converter to operate in one of the two-to-one mode, the three-to-one mode, the second-order inductor switching mode and the third-order inductor switching mode according to the first voltage, so as to convert the The second voltage is maintained within the first predetermined range. The switched capacitor voltage conversion method as claimed in claim 13, wherein the switched capacitor converter includes a series-parallel switched capacitor converter. The switched capacitor voltage conversion method as described in claim 20, wherein the series-parallel switched capacitor converter (series-parallel switched capacitor converter) includes a half series-parallel switched capacitor converter (2-to-1 series -parallel switched capacitor converter), one-third series-parallel switched capacitor converter (3-to-1 series-parallel switched capacitor converter), one-quarter series-parallel switched capacitor converter (4-to-1 series -parallel switched capacitor converter) or 5-to-1 series-parallel switched capacitor converter (5-to-1 series-parallel switched capacitor converter). The switched capacitor voltage conversion method as claimed in claim 13, wherein the DC potential is ground potential. The switched capacitive voltage conversion method as claimed in claim 13, further comprising: sensing the current flowing through the at least one inductor to generate at least one current sensing signal; and generating the charging operation signal according to the current sensing signal. , the at least one discharge operation signal and the inductor operation signal. The switched capacitive voltage conversion method as described in claim 23 further includes: sensing the second voltage or the first voltage to generate a voltage sensing signal, and in the inductor switching mode, based on the voltage sensing signal to generate the inductor operation signal.

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