Power conversion system, electronic device including the same, and integrated circuit

The present invention provides a power conversion system, an electronic device including the same, and an integrated circuit, and relates to the field of power supplies. By arranging a second switch series branch connected to a switch series branch of a switch capacitor converter, and matching a switch in the second switch series branch and a switch in the switch series branch of the switch capacitor converter, a function of a three-level buck converter is achieved, so that the three-level buck converter and the switch capacitor converter are integrated. The quantity of switches is reduced. The volume is small. The costs are low, and high efficiency of a whole process of charging a battery of the electronic device is achieved while supplying power to a power consumption unit of the electronic device.

PRIORITY CLAIM

This application claims the benefit of and priority to Chinese patent Application No. 202210115196.3, filed on Feb. 5, 2022, which is hereby incorporated by reference in its entirety.

TECHNICAL FIELD

The present invention relates to the field of power supplies, and in particular, to a power conversion system, an electronic device including the same, and an integrated circuit.

BACKGROUND

With the continuous advances of technologies, various electronic devices such as portable devices (including mobile phones, tablet computers, digital cameras, MP3 players and/or other similar electronic devices) have become popular. For each electronic device, a plurality of rechargeable battery units connected in series and/or in parallel may be used to form a rechargeable battery configured to store electric energy. The rechargeable battery may be charged by an adapter connected to the electronic device and a power conversion structure in the electronic device, to restore energy of batteries, and the rechargeable battery may be any type of battery such as a lithium ion (Li-ion) battery.

The power conversion structure adapted to charge the rechargeable battery is diversified. Referring to a typical buck converter shown inFIG.1and a typical three-level buck converter shown inFIG.2, the converters are inductor-based buck converters, and are widely applied to power conversion structures for charging batteries. InFIG.1, a switch S1, a switch S2, an inductor L, an input side capacitor Cin, and an output side capacitor Cout form the typical buck converter. InFIG.2, a switch S1, a switch S2, a switch S3, a switch S4, an inductor L, a flying capacitor Cf, an input side capacitor Cin, and an output side capacitor Cout form the typical three-level buck converter. However, the foregoing two converters have relatively low efficiency, the efficiency of the typical buck converter shown inFIG.1is about 92%, and the efficiency of the typical three-level buck converter shown inFIG.2is about 95.5%, failing to meet requirements of the market for quick charging and high efficiency of power conversion structures. Referring to a typical switch capacitor converter shown inFIG.3and a typical two-phase switch capacitor converter shown inFIG.4, the converters can achieve an input-to-output ratio, namely, a conversion ratio of 1:1 or 2:1. InFIG.3, a switch S1, a switch S2, a switch S3, a switch S4, a flying capacitor Cf, an input side capacitor Cin, and an output side capacitor Cout form the typical switch capacitor converter. InFIG.4, switches S1to S8, flying capacitors Cf1and Cf2, an input side capacitor Cin, and an output side capacitor Cout form the typical two-phase switch capacitor converter. Because of compact structures and relatively high efficiency, switch capacitor converters, particularly, the typical two-phase switch capacitor converter shown inFIG.4are widely applied.

With the development of power supply technologies, a power conversion structure formed through collaboration between an inductor-based buck converter and a switch capacitor converter is recognized to charge a rechargeable battery, may have advantages of both the inductor-based buck converter and the switch capacitor converter, and may be flexibly configured to meet requirements of the battery at different charging stages, where the battery includes a trickle charging stage, a pre-charging stage, a constant current charging stage, a constant voltage charging stage, and a cutoff charging stage. However, a current solution of collaboration between an inductor-based buck converter and a switch capacitor converter has a large quantity of switches, high costs, and a large volume.

That is, none of the current power conversion structures can meet high efficiency in a whole process of charging a battery, and the power conversion structures have high costs and large volumes, contradicting a development trend toward miniaturization, low costs, and high efficiency of power converters.

SUMMARY

The present invention provides a power conversion system, including: a power conversion structure, including a first switch series branch, a second switch series branch, a seventh switch, an inductor unit, and a first flying capacitor, where the first switch series branch includes a first switch, a second switch, a third switch, and a fourth switch connected in series, the second switch series branch includes a fifth switch and a sixth switch connected in series, a first terminal of the first switch series branch is connected to an input terminal, the input terminal is configured to receive an input voltage, a second terminal of the first switch series branch is grounded, a common node of the first switch and the second switch is connected to a first terminal of the first flying capacitor and a first terminal of the second switch series branch, a common node of the third switch and the fourth switch is connected to a second terminal of the first flying capacitor and a second terminal of the second switch series branch, a common node of the fifth switch and the sixth switch is connected to a first terminal of the inductor unit, a second terminal of the inductor unit is connected to an output terminal, the seventh switch includes a first terminal, a second terminal, and a control terminal, the first terminal of the seventh switch is connected to the output terminal, the second terminal of the seventh switch is connected to a common node of the second switch and the third switch, the common node of the second switch and the third switch is configured to be connected to a battery, the control terminal of the seventh switch is configured to receive a switch control signal, the second terminal of the inductor unit is further connected to a first terminal of a capacitor unit, and a second terminal of the capacitor unit is grounded; and a controller, where the controller is configured to: control, when the input terminal receives an input voltage, the power conversion structure to work in one of a plurality of working modes, where the plurality of working modes include: a first working mode, where the controller controls the seventh switch to be in a saturated state or completely turned-on state and the second switch and the third switch to be turned off, and controls the first switch, the fourth switch, the fifth switch, and the sixth switch to work to supply power to a load connected to the output terminal and charge the battery connected to the common node of the second switch and the third switch; a second working mode, where the controller controls the seventh switch to be turned on, controls the fifth switch and the sixth switch to be turned off, and controls the first switch, the second switch, the third switch, and the fourth switch to work to charge the battery connected to the common node of the second switch and the third switch and supply power to the load connected to the output terminal; and a third working mode, where the controller controls the seventh switch, the second switch, and the third switch to be turned off, and the first switch, the fourth switch, the fifth switch, and the sixth switch work, to supply power to the load connected to the output terminal.

The present invention further provides an electronic device, including: the power conversion system described above; a battery, where a first terminal of the battery is connected to the common node of the second switch and the third switch, and a second terminal of the battery is grounded; and a load, where the load is connected to the output terminal, to receive an electric signal outputted by the output terminal.

The present invention further provides a power conversion system, including: a power conversion structure, including a first switch series branch, a second switch series branch, a seventh switch, an inductor unit, and a first flying capacitor, where the first switch series branch includes a first switch, a second switch, a third switch, and a fourth switch connected in series, the second switch series branch includes a fifth switch and a sixth switch connected in series, a first terminal of the first switch series branch is formed into an input terminal, the input terminal is configured to receive an input voltage, a second terminal of the first switch series branch is grounded, a common node of the first switch and the second switch is connected to a first terminal of the first flying capacitor and a first terminal of the second switch series branch, a common node of the third switch and the fourth switch is connected to a second terminal of the first flying capacitor and a second terminal of the second switch series branch, a common node of the fifth switch and the sixth switch is connected to a first terminal of the inductor unit, a second terminal of the inductor unit is connected to an output terminal, the seventh switch includes a first terminal, a second terminal, and a control terminal, the first terminal of the seventh switch is connected to the output terminal, the second terminal of the seventh switch is connected to a common node of the second switch and the third switch, the common node of the second switch and the third switch is configured to be connected to a battery, the control terminal of the seventh switch is configured to receive a switch control signal, the second terminal of the inductor unit is further connected to a first terminal of a capacitor unit, and a second terminal of the capacitor unit is grounded; and a controller, where the controller is configured to: when the input voltage received by the input terminal is zero volts and the battery connected to the common node of the second switch and the third switch supplies power to a load connected to the output terminal, in response to a case that a voltage of the output terminal is reduced to a threshold voltage, the controller controls the power conversion structure to work in an output voltage back-adjustment mode; and in the output voltage back-adjustment mode, the controller controls the first switch, the second switch, the third switch, the fourth switch, the fifth switch, and the sixth switch to work to increase the voltage of the output terminal to a value greater than a voltage of the battery.

The present invention further provides an electronic device, including: the power conversion system described above; a battery, where a first terminal of the battery is connected to the common node of the second switch and the third switch, and a second terminal of the battery is grounded; and a load, where the load is connected to the output terminal, to receive an electric signal outputted by the output terminal.

The present invention further provides an integrated circuit, including: an input terminal, configured to receive an input voltage; a first switch, connected between the input terminal and a first top electrode plate node, where the first switch has a first control node; a second switch, connected between the first top electrode plate node and a battery terminal, where the second switch has a second control node, and the battery terminal is configured to be connected to a battery; a third switch, connected between the battery terminal and a first bottom electrode plate node, where the third switch has a third control node; a fourth switch, connected between the first bottom electrode plate node and a grounding terminal, where the fourth switch has a fourth control node; a conversion node terminal, configured to provide an electric signal at a conversion node to an inductor, where the inductor is connected in series between the conversion node terminal and a system terminal, and a capacitor is connected between the system terminal and the grounding terminal; a fifth switch, connected between the first top electrode plate node and the conversion node terminal, where the fifth switch has a fifth control node; a sixth switch, connected between the first bottom electrode plate node and the conversion node terminal, where the sixth switch has a sixth control node; a seventh switch, connected between the system terminal and the battery terminal, where the seventh switch has a seventh control node; a first flying capacitor terminal and a second flying capacitor terminal, configured to be respectively connected to a first terminal and a second terminal of a first flying capacitor, where the first flying capacitor terminal is connected to the first top electrode plate node, and the second flying capacitor terminal is connected to the first bottom electrode plate node.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

The following clearly and completely describes the technical solutions in the present disclosure with reference to the accompanying drawings. Apparently, the described embodiments are some rather than all of the embodiments of the present invention. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

In an embodiment of the present invention, a power conversion system is provided, and may be applied to an electronic device. For details, reference is made to a schematic diagram of a power conversion system according to an embodiment of the present invention shown inFIG.5. The power conversion system includes a power conversion structure100and a controller400, where the power conversion structure100includes: a first switch series branch110, a second switch series branch120, a seventh switch Q7, an inductor unit L1, and a first flying capacitor Cf1, where the first switch series branch110includes a first switch Q1, a second switch Q2, a third switch Q3, and a fourth switch Q4connected in series, the second switch series branch120includes a fifth switch Q5and a sixth switch Q6connected in series, a first terminal d11of the first switch series branch110is connected to an input terminal din, the input terminal din is configured to receive an input voltage Vin, a second terminal d12of the first switch series branch110is grounded, a common node of the first switch Q1and the second switch Q2is connected to a first terminal of the first flying capacitor Cf1and a first terminal d21of the second switch series branch120, a common node of the third switch Q3and the fourth switch Q4is connected to a second terminal of the first flying capacitor Cf1and a second terminal d22of the second switch series branch120, a common node of the fifth switch Q5and the sixth switch Q6is connected to a first terminal of the inductor unit L1, a second terminal of the inductor unit L1is connected to an output terminal dout, the seventh switch Q7includes a first terminal d31, a second terminal d32, and a control terminal d33, the first terminal d31of the seventh switch Q7is connected to the output terminal dout, the output terminal dout is connected to a load200, the second terminal d32of the seventh switch Q7is connected to a common node of the second switch Q2and the third switch Q3, the common node of the second switch Q2and the third switch Q3is configured to be connected to a battery300, the control terminal d33of the seventh switch Q7is configured to receive a switch control signal, the second terminal of the inductor unit L1is further connected to a first terminal of a capacitor unit C1, and a second terminal of the capacitor unit C1is grounded; and where the controller400is configured to: control, when the input terminal din receives an input voltage Vin, the power conversion structure100to work in one of a plurality of working modes, where the plurality of working modes include: a first working mode, where the controller400controls the seventh switch Q7to be in a saturated state or completely turned-on state, controls the second switch Q2and the third switch Q3to be turned off, and controls the first switch Q1, the fourth switch Q4, the fifth switch Q5, and the sixth switch Q6to work to supply power to the load200connected to the output terminal dout and charge the battery300connected to the common node of the second switch Q2and the third switch Q3; a second working mode, where the controller400controls the seventh switch Q7to be turned on, controls the fifth switch Q5and the sixth switch Q6to be turned off, and controls the first switch Q1, the second switch Q2, the third switch Q3, and the fourth switch Q4to work to charge the battery300connected to the common node of the second switch Q2and the third switch Q3and supply power to the load200connected to the output terminal dout; and a third working mode, where the controller400controls the seventh switch Q7, the second switch Q2, and the third switch Q3to be turned off, and controls the first switch Q1, the fourth switch Q4, the fifth switch Q5, and the sixth switch Q6to work to supply power to the load200connected to the output terminal dout.

In an embodiment, the load200may be a power consumption unit of an electronic device, such as a power consumption unit of portable devices (including mobile phones, tablet computers, digital cameras, MP3 players and/or other similar electronic devices). In an embodiment, the battery300may be a rechargeable battery in an electronic device, such as a rechargeable battery in portable devices (including mobile phones, tablet computers, digital cameras, MP3 players and/or other similar electronic devices).

As shown inFIG.5, the first switch Q1, the second switch Q2, the third switch Q3, the fourth switch Q4, and the first flying capacitor Cf1form a typical switch capacitor converter, and the first switch Q1, the fifth switch Q5, the sixth switch Q6, the fourth switch Q4, the inductor unit L1, and the first flying capacitor Cf1form a typical three-level buck converter. In this way, the power conversion structure shown inFIG.5may integrate the three-level buck converter and the switch capacitor converter. In addition, as shown inFIG.5, switches in the second switch series branch120and switches in the first switch series branch110are collaboratively used to implement a function of the three-level buck converter, and the quantity of switches is reduced, so that the power conversion structure provided in the present invention has a small volume and low costs, and can have advantages of both the three-level buck converter and the switch capacitor converter, to achieve high efficiency of a whole process of charging the battery300of the electronic device while supplying power to the power consumption unit of the electronic device, and implement stable and reliable running of the electronic device. In addition, the first flying capacitor Cf1of the three-level buck converter and the switch capacitor converter is shared, which can further reduce the volume of the power conversion structure.

In an embodiment of actual application, the whole process of charging the battery300includes a trickle charging stage, a pre-charging stage, a constant voltage charging stage, a constant current charging stage, and a cutoff charging stage. When the battery300needs to be charged, the input terminal din receives an input voltage, that is, the input terminal din is connected to an external power supply. When the battery300is at the trickle charging stage, the pre-charging stage, and the constant voltage charging stage, the controller400is configured to control the second switch Q2and the third switch Q3in the power conversion structure100to be turned off, control the first switch Q1, the fourth switch Q4, the fifth switch Q5, and the sixth switch Q6to work, and control the seventh switch Q7to be in the saturated state or completely turned-on state, to charge the battery300and supply power to the load200, that is, the power conversion structure works in the first working mode. That the first switch Q1, the fourth switch Q4, the fifth switch Q5, and the sixth switch Q6work means that the first switch Q1, the fourth switch Q4, the fifth switch Q5, and the sixth switch Q6switch between being turned on and being turned off with a specific frequency. In this case, the power conversion structure works in a state of a typical three-level buck converter. A working state of the three-level buck converter in a low voltage mode (an output voltage is less than ½ of an input voltage) is introduced below. For details, reference is made to a schematic diagram of a working waveform of a power conversion structure according to an embodiment of the present invention shown inFIG.6, where a horizontal coordinate is a time t, and a vertical coordinate is a switch control signal SC. First, at a to moment, the first switch Q1and the sixth switch Q6are turned on, and the fifth switch Q5and the fourth switch Q4are turned off, to form a current path sequentially passing through a positive terminal of the input voltage, the first switch Q1, the first flying capacitor Cf1, the sixth switch Q6, the inductor unit L1, and a negative terminal of the input voltage, so that the first flying capacitor Cf1performs energy storage, and the inductor unit L1performs energy storage; then, at a t1moment, the first switch Q1is turned off, and the fourth switch Q4is turned on, to form a current path passing through the inductor unit L1, the fourth switch Q4, and the sixth switch Q6, so that the inductor unit L1performs current following; then, at a t2moment, the sixth switch Q6is turned off, and the fifth switch Q5is turned on, to form a current path passing through the first flying capacitor Cf1, the fifth switch Q5, the inductor unit L1, and the fourth switch Q4, so that the inductor unit L1performs energy storage; and then, at a t3moment, the fifth switch Q5is turned off, and the sixth switch Q6is turned on, to form a current path passing through the inductor unit L1, the fourth switch Q4, and the sixth switch Q6, so that the inductor unit L1performs current following. That is, the first switch Q1, the fourth switch Q4, the fifth switch Q5, and the sixth switch Q6cyclically work with the foregoing switching period, to implement a function of the three-level buck converter and supply power to the load200. In addition, in a working process of the three-level buck converter, the seventh switch Q7is always in the saturated state or completely turned-on state, so that trickle charging, pre-charging, and constant voltage charging are performed for the battery300simultaneously. In the constant current charging stage of the battery300, the controller400is configured to control the fifth switch Q5and the sixth switch Q6in the power conversion structure100to be turned off, control the first switch Q1, the second switch Q2, the third switch Q3, and the fourth switch Q4to work, and control the seventh switch Q7to be turned on, to charge the battery300and supply power to the load200, that is, the power conversion structure works in the second working mode. That the first switch Q1, the second switch Q2, the third switch Q3, and the fourth switch Q4work means that the first switch Q1, the second switch Q2, the third switch Q3, and the fourth switch Q4switch between being turned on and being turned off with a specific frequency. In this case, the power conversion structure works in a state of a typical switch capacitor converter. A working state of the switch capacitor converter in a low voltage mode (an output voltage is less than ½ of an input voltage) is introduced below. For details, reference is made to a schematic diagram of a working waveform of a power conversion structure according to an embodiment of the present invention shown inFIG.7, where a horizontal coordinate is a time t, and a vertical coordinate is a switch control signal SC. First, at a to moment, the first switch Q1and the third switch Q3are turned on, and the second switch Q2and the fourth switch Q4are turned off, to form a current path passing through a positive terminal of the input voltage, the first switch Q1, the first flying capacitor Cf1, the third switch Q3, the battery300, and a negative terminal of the input voltage, so that the first flying capacitor Cf1performs energy storage and charges the battery300; and then, at t1moment, the second switch Q2and the fourth switch Q4are turned on, and the first switch Q1and the third switch Q3are turned off, to form a current path passing through the first flying capacitor Cf1, the second switch Q2, the battery300, and the fourth switch Q4, so that the first flying capacitor Cf1charges the battery300. That is, the first switch Q1, the second switch Q2, the third switch Q3, and the fourth switch Q4cyclically work with the foregoing switching period, to implement a function of the switch capacitor converter and charge the battery300with a constant current. In addition, in a working process of the switch capacitor converter, the seventh switch Q7is always in the turned-on state, and then supplies power to the load200simultaneously. In the cutoff charging stage of the battery300, the controller400is configured to control the second switch Q2and the third switch Q3in the power conversion structure100to be turned off, and control the first switch Q1, the fourth switch Q4, the fifth switch Q5, and the sixth switch Q6to work, that is, work again in a state of the three-level buck converter shown inFIG.6to supply power to the load200. In addition, in a working process of the three-level buck converter, the seventh switch Q7is always in the turned-off state, so that the battery300enters the cutoff charging stage, that is, the power conversion structure works in the third working mode. In this way, high efficiency of a whole process of charging the battery300of the electronic device is achieved while supplying power to the power consumption unit (that is, the load200) of the electronic device.

In an embodiment of actual application, when the battery300does not need to be charged, the input terminal din receives no input voltage, that is, the input terminal din is not connected to an external power supply or a voltage provided by an external power supply is 0 V, that is, no input voltage is inputted to the input terminal din, so that the controller400is configured to control the seventh switch Q7in the power conversion structure100to be turned on, and control each of the first switch Q1, the second switch Q2, the third switch Q3, the fourth switch Q4, the fifth switch Q5, and the sixth switch Q6to be turned off, that is, the power conversion structure100does not work. In this case, the battery300connected to the common node of the second switch Q2and the third switch Q3supplies power to the load200connected to the output terminal dout. In this case, the power conversion structure100works in the fourth working mode.

In the foregoing embodiment, the seventh switch Q7is configured to be turned on to supply power to the power consumption unit (that is, the load200) of the electronic device, and meanwhile the battery300of the electronic device is charged; or the battery300of the electronic device supplies power to the load200, and the seventh switch Q7is configured to be turned off to supply power to only the power consumption unit (that is, the load200) of the electronic device, that is, the seventh switch Q7implements a power path management function.

In an embodiment of actual application, when the seventh switch Q7is turned on, the power conversion structure100does not work, and the battery300supplies power to the load200, that is, when the power conversion structure100works in the fourth working mode, in response to a case that the voltage of the output terminal dout is reduced to the threshold voltage, the controller400is configured to control the first switch Q1, the second switch Q2, the third switch Q3, the fourth switch Q4, the fifth switch Q5, and the sixth switch Q6in the power conversion structure wo to work to increase the voltage of the output terminal dout to a value greater than the voltage of the battery300, to supply power to the load200connected to the output terminal dout, that is, the power conversion structure100works in the output voltage back-adjustment mode. That the first switch Q1, the second switch Q2, the third switch Q3, the fourth switch Q4, the fifth switch Q5, and the sixth switch Q6work means that the first switch Q1, the second switch Q2, the third switch Q3, the fourth switch Q4, the fifth switch Q5, and the sixth switch Q6switch between being turned on and being turned off with a specific frequency. For details, reference is made to a schematic diagram of a working waveform of a power conversion structure according to an embodiment of the present invention shown inFIG.8, where a horizontal coordinate is a time t, and a vertical coordinate is a switch control signal SC. First, at a to moment, the first switch Q1, the third switch Q3, and the fifth switch Q5are turned on, and the second switch Q2, the fourth switch Q4, and the sixth switch Q6are turned off, so that the first flying capacitor Cf1discharges, the inductor unit L1performs energy storage, a current IL of the inductor unit is increased, and the voltage of the first terminal of the inductor unit L1is twice the voltage of the battery300. For details, reference may be made to a schematic diagram of a working principle of a first working stage of a power conversion structure according to an embodiment of the present invention shown inFIG.9a. Then, at a t1moment, the sixth switch Q6is turned on, and the fifth switch Q5is turned off, so that the inductor unit L1performs current following, the current IL of the inductor unit is gradually reduced, and the voltage of the first terminal of the inductor unit L1is the voltage of the battery300. For details, reference may be made to a schematic diagram of a working principle of a second working stage of a power conversion structure according to an embodiment of the present invention shown inFIG.9b. Then, at a t2moment, the first switch Q1, the third switch Q3, and the sixth switch Q6are turned off, and the second switch Q2, the fourth switch Q4, and the fifth switch Q5are turned on, so that the first flying capacitor Cf1charges, the inductor unit L1continues to perform current following, the current IL of the inductor unit is gradually reduced, and the voltage of the first terminal of the inductor unit L1is the voltage of the battery300. For details, reference may be made to a schematic diagram of a working principle of a third working stage of a power conversion structure according to an embodiment of the present invention shown inFIG.9c. At a t3moment, a next switching period is entered. In this way, the voltage of the first terminal of the inductor unit L1(switching between the voltage of the battery and twice the voltage of the battery) is adjusted to increase the voltage outputted to the load200from the voltage of the battery to a value greater than the voltage of the battery, to avoid poor user experience such as shutdown caused because the voltage received by the load200is less than the threshold voltage.

More specifically, in an embodiment, in the working process shown inFIG.8, the first switch Q1, the second switch Q2, the third switch Q3, the fourth switch Q4, and the first flying capacitor form a switch capacitor converter, and a conversion ratio between an input voltage and an output voltage of the switch capacitor converter is 2:1. The voltage of the first terminal of the inductor unit L1may switch between the voltage of the battery and twice the voltage of the battery, and the voltage outputted to the load200may be increased. In another embodiment, the conversion ratio between the input voltage and the output voltage of the switch capacitor converter may alternatively be N:1, where N is an integer greater than 2. More specifically, in an embodiment, in the working process shown inFIG.8, magnitude of a voltage outputted by the output terminal dout may be adjusted by controlling a duty cycle of the fifth switch Q5. In this way, the voltage outputted to the load200is adjustable. For example, when the duty cycle of the fifth switch Q5is 1, a filtering unit formed by the inductor unit L1and the capacitor unit C1filters the voltage of the first terminal of the inductor unit L1(switching between the voltage of the battery and twice the voltage of the battery, for example, the switch capacitor converter wo works in a charge pump mode in which a conversion ratio is 2:1), so that the voltage outputted by the output terminal dout is close to 1.5 times the voltage of the battery, that is, the voltage outputted to the load200is increased from the voltage of the battery to a value close to 1.5 times the voltage of the battery.

In an embodiment, in the working process shown inFIG.8, the seventh switch Q7is always in a turned-off state. In this case, the power conversion structure100supplies power to the load200.

For details, reference is made to a schematic circuit diagram of a power conversion system according to another embodiment of the present invention shown inFIG.10. As shown inFIG.10, the power conversion structure100further includes a second flying capacitor Cf2and a third switch series branch130, where the third switch series branch130includes an eighth switch Q8, a ninth switch Q9, a tenth switch Q10, and an eleventh switch Q11connected in series, a first terminal d41of the third switch series branch130is connected to the first terminal d11of the first switch series branch110, a second terminal d42of the third switch series branch130is connected to the second terminal d12of the first switch series branch110, a common node of the eighth switch Q8and the ninth switch Q9is connected to a first terminal of the second flying capacitor Cf2, a common node of the tenth switch Q10and the eleventh switch Q11is connected to a second terminal of the second flying capacitor Cf2, and a common node of the ninth switch Q9and the tenth switch Q10is connected to the common node of the second switch Q2and the third switch Q3. In this way, the eighth switch Q8, the ninth switch Q9, the tenth switch Q10, the eleventh switch Q11, and the second flying capacitor Cf2form a second-phase switch capacitor converter, that is,FIG.10is integration of a two-phase switch capacitor converter and a three-level buck converter, thereby further improving the power level of the power conversion structure. Certainly, in an embodiment of the present invention, n second-phase switch capacitor converters connected in parallel shown inFIG.10may alternatively be included, where n is a positive integer, to implement a (n+1)-phase switch capacitor converter. The principle is stated explicitly with only two phases inFIG.10.

The power conversion system shown inFIG.10may work in a fifth working mode of the plurality of working modes. In the fifth working mode, the controller400is configured to control the eighth switch Q8, the ninth switch Q9, the tenth switch Q10, and the eleventh switch Q11in the power conversion structure100to work to charge the battery300connected to the common node of the second switch Q2and the third switch Q3, control the first switch Q1, the fourth switch Q4, the fifth switch Q5, and the sixth switch Q6to work to supply power to the load200connected to the output terminal dout, and control the second switch Q2and the third switch Q3to be turned off. That the eighth switch Q8, the ninth switch Q9, the tenth switch Q10, and the eleventh switch Q11work means that the eighth switch Q8, the ninth switch Q9, the tenth switch Q10, and the eleventh switch Q11switch between being turned on and being turned off with a specific frequency, so that the eighth switch Q8, the ninth switch Q9, the tenth switch Q10, the eleventh switch Q11, and the second flying capacitor Cf2form a second-phase switch capacitor converter to charge the battery300. That the first switch Q1, the fourth switch Q4, the fifth switch Q5, and the sixth switch Q6work means that the first switch Q1, the fourth switch Q4, the fifth switch Q5, and the sixth switch Q6switch between being turned on and being turned off with a specific frequency, so that the first switch Q1, the fourth switch Q4, the fifth switch Q5, the sixth switch Q6, the first flying capacitor Cf1, and the inductor unit L1form a three-level buck converter to supply power to the load200connected to the output terminal dout.

In an embodiment of the present invention, a switch may alternatively be connected in series between the first terminal d11of the first switch series branch110and the input terminal din, to implement a function of preventing current backflow.

In an embodiment of the present invention, each of the foregoing switches is an MOSFET, and includes a source, a drain, and a gate. A drain of the first switch Q1forms the first terminal of d11the first switch series branch110, a source of the fourth switch Q4forms the second terminal d12of the first switch series branch110, a source of the first switch Q1is connected to a drain of the second switch Q2and forms the common node of the first switch Q1and the second switch Q2, a source of the second switch Q2is connected to a drain of the third switch Q3and forms the common node of the second switch Q2and the third switch Q3, a source of the third switch Q3is connected to a drain of the fourth switch Q4and forms the common node of the third switch Q3and the fourth switch Q4, a drain of the fifth switch Q5forms the first terminal d21of the second switch series branch120, a source of the sixth switch Q6forms the second terminal d22of the second switch series branch120, a source of the fifth switch Q5is connected to a drain of the sixth switch Q6and forms the common node of the fifth switch Q5and the sixth switch Q6, a drain of the seventh switch Q7is the first terminal d31of the seventh switch Q7, a source of the seventh switch Q7is the second terminal d32of the seventh switch Q7, and a gate of each of the first switch Q1to the seventh switch Q7receives a switch control signal. Switches in the third switch series branch130and switches in the first switch series branch110shown inFIG.10have the same connection relationship. Details are not described herein again.

In an embodiment of the present invention, the foregoing switches may alternatively be bipolar junction transistors, super junction transistors, insulated gate bipolar transistors, power devices based on gallium nitride, and/or similar devices, as long as the devices can receive a switch control signal and be turned on or turned off in the industry.

In an embodiment of the present invention, each of the foregoing switches includes a single switch. During actual application, each switch may include a plurality of switches connected in series and/or in parallel.

In an embodiment of the present invention, an electronic device10is further provided. The electronic device10may be, for example, a portable device (including mobile phones, tablet computers, digital cameras, MP3 players and/or other similar electronic devices). For details, reference is made to a schematic structural diagram of an electronic device according to an embodiment of the present invention shown inFIG.11. The electronic device includes the foregoing power conversion system, for example, the power conversion system shown inFIG.5; a battery300, where a first terminal of the battery300is connected to the common node of the second switch Q2and the third switch Q3, and a second terminal of the battery300is grounded; and a load200in the electronic device10, where the load200is connected to the output terminal dout, to receive an electric signal outputted by the output terminal dout. The load200is a power consumption unit of the electronic device.

In another embodiment of the present invention, when the power consumption unit in the electronic device needs to be supplied with power to and/or the battery300in the electronic device needs to be charged, an adapter20is connected to the electronic device10, to provide an input voltage to the input terminal din of the power conversion system.

The present invention further provides a power conversion system. Reference is made again to a schematic structural diagram of a power conversion system according to another embodiment of the present invention shown inFIG.5. As shown inFIG.5, the power conversion system includes a power conversion structure100and a controller400, where the power conversion structure100includes: a first switch series branch110, a second switch series branch120, a seventh switch Q7, an inductor unit L1, and a first flying capacitor Cf1, where the first switch series branch110includes a first switch Q1, a second switch Q2, a third switch Q3, and a fourth switch Q4connected in series, the second switch series branch120includes a fifth switch Q5and a sixth switch Q6connected in series, a first terminal d11of the first switch series branch110is connected to an input terminal din, the input terminal din is configured to receive an input voltage Vin, a second terminal d12of the first switch series branch110is grounded, a common node of the first switch Q1and the second switch Q2is connected to a first terminal of the first flying capacitor Cf1and a first terminal d21of the second switch series branch120, a common node of the third switch Q3and the fourth switch Q4is connected to a second terminal of the first flying capacitor Cf1and a second terminal d22of the second switch series branch120, a common node of the fifth switch Q5and the sixth switch Q6is connected to a first terminal of the inductor unit L1, a second terminal of the inductor unit L1is connected to an output terminal dout, the seventh switch Q7includes a first terminal d31, a second terminal d32, and a control terminal d33, the first terminal d31of the seventh switch Q7is connected to the output terminal dout, the output terminal dout is connected to a load200, the second terminal d32of the seventh switch Q7is connected to a common node of the second switch Q2and the third switch Q3, the common node of the second switch Q2and the third switch Q3is configured to be connected to a battery300, the control terminal d33of the seventh switch Q7is configured to receive a switch control signal, the second terminal of the inductor unit L1is further connected to a first terminal of a capacitor unit C1, and a second terminal of the capacitor unit C1is grounded; and where the controller400is configured to: when the input voltage Vin received by the input terminal din is zero volts and the battery300connected to the common node of the second switch Q2and the third switch Q3supplies power to a load200connected to the output terminal dout, in response to a case that a voltage of the output terminal dout is reduced to a threshold voltage, control the first switch Q1, the second switch Q2, the third switch Q3, the fourth switch Q4, the fifth switch Q5, and the sixth switch Q6in the power conversion structure100to work to increase the voltage of the output terminal dout to a value greater than a voltage of the battery300.

That is, in an embodiment of actual application, when the battery300does not need to be charged, the input terminal din receives no input voltage, that is, the input terminal din is not connected to an external power supply, that is, the input voltage Vin received by the input terminal din is zero volts, so that the controller400is configured to control the seventh switch Q7in the power conversion structure100to be turned on, and control each of the first switch Q1, the second switch Q2, the third switch Q3, the fourth switch Q4, the fifth switch Q5, and the sixth switch Q6to be turned off, that is, the power conversion structure100does not work. In this case, the battery300supplies power to the load200. In this working process, in response to a case that the voltage of the output terminal dout is reduced to the threshold voltage, the controller400is configured to control the power conversion structure100to work in the output voltage back-adjustment mode, that is, control the first switch Q1, the second switch Q2, the third switch Q3, the fourth switch Q4, the fifth switch Q5, and the sixth switch Q6in the power conversion structure100to work to increase the voltage of the output terminal dout to a value greater than the voltage of the battery300, to supply power to the load200connected to the output terminal dout. That the first switch Q1, the second switch Q2, the third switch Q3, the fourth switch Q4, the fifth switch Q5, and the sixth switch Q6work means that the first switch Q1, the second switch Q2, the third switch Q3, the fourth switch Q4, the fifth switch Q5, and the sixth switch Q6switch between being turned on and being turned off with a specific frequency. A specific working principle thereof is similar to those described inFIG.8,FIG.9a,FIG.9b, andFIG.9c. Details are not described herein again.

More specifically, in an embodiment, in the working process shown inFIG.8, the first switch Q1, the second switch Q2, the third switch Q3, the fourth switch Q4, and the first flying capacitor form a switch capacitor converter, and a conversion ratio between an input voltage and an output voltage of the switch capacitor converter is 2:1. The voltage of the first terminal of the inductor unit L1may switch between the voltage of the battery and twice the voltage of the battery, and the voltage outputted to the load200may be increased. In another embodiment, the conversion ratio between the input voltage and the output voltage of the switch capacitor converter may alternatively be N:1, where N is an integer greater than 2. More specifically, in an embodiment, in the working process shown inFIG.8, magnitude of a voltage outputted by the output terminal dout may be adjusted by controlling a duty cycle of the fifth switch Q5. In this way, the voltage outputted to the load200is adjustable. For example, when the duty cycle of the fifth switch Q5is 1, a filtering unit formed by the inductor unit L1and the capacitor unit C1filters the voltage of the first terminal of the inductor unit L1(switching between the voltage of the battery and twice the voltage of the battery, for example, the switch capacitor converter100works in a charge pump mode in which a conversion ratio is 2:1), so that the voltage outputted by the output terminal dout is close to 1.5 times the voltage of the battery, that is, the voltage outputted to the load200is increased from the voltage of the battery to a value close to 1.5 times the voltage of the battery.

In an embodiment, in the working process shown inFIG.8, the seventh switch Q7is always in a turned-off state. In this case, the power conversion structure100supplies power to the load200.

In an embodiment of actual application, When the battery300needs to be charged, the input terminal din receives an input voltage, that is, the input terminal din is connected to an external power supply. The controller400is configured to: control, when the input terminal din receives an input voltage, the power conversion structure100to work in one of a plurality of working modes, where the plurality of working modes include: a first working mode, where the controller400controls the seventh switch Q7to be in a saturated state or completely turned-on state, controls the second switch Q2and the third switch Q3to be turned off, and controls the first switch Q1, the fourth switch Q4, the fifth switch Q5, and the sixth switch Q6to work to supply power to the load200connected to the output terminal dout and charge the battery300connected to the common node of the second switch Q2and the third switch Q3; a second working mode, where the controller400controls the seventh switch Q7to be turned on, controls the fifth switch Q5and the sixth switch Q6to be turned off, and controls the first switch Q1, the second switch Q2, the third switch Q3, and the fourth switch Q4to work to charge the battery300connected to the common node of the second switch Q2and the third switch Q3and supply power to the load200connected to the output terminal dout; and a third working mode, where the controller400controls the seventh switch Q7, the second switch Q2, and the third switch Q3to be turned off, and controls the first switch Q1, the fourth switch Q4, the fifth switch Q5, and the sixth switch Q6to work to supply power to the load200connected to the output terminal dout. The principle of the first working mode is shown inFIG.6, the principle of the second working mode is shown inFIG.7, and the principle of the third working mode is shown inFIG.6. The principles are similar to that of the foregoing whole charging process of the trickle charging stage, the pre-charging stage, the constant current charging stage, the constant voltage charging stage, and the cutoff charging stage of the battery300. Details are not described herein again.

In an embodiment, the power conversion structure100further includes a second flying capacitor Cf2and a third switch series branch130, which are specifically shown inFIG.10. Details are not described herein again.

In an embodiment of the present invention, an electronic device10is further provided. The electronic device10may be, for example, a portable device (including mobile phones, tablet computers, digital cameras, MP3 players and/or other similar electronic devices). Specifically, the electronic device shown inFIG.11is not described in detail herein again. The electronic device includes the foregoing power conversion system, for example, the power conversion system shown inFIG.5; a battery300, where a first terminal of the battery300is connected to the common node of the second switch Q2and the third switch Q3, and a second terminal of the battery300is grounded; and a load200in the electronic device10, where the load200is connected to the output terminal dout, to receive an electric signal outputted by the output terminal dout. The load200is a power consumption unit of the electronic device.

In another embodiment of the present invention, when the power consumption unit in the electronic device does not need to be supplied with power to and/or the battery300in the electronic device does not need to be charged, the adapter20is unplugged from the electronic device10, the controller400controls the seventh switch Q7to be turned on, and the battery300supplies power to the load200; and when the voltage outputted to the load200is excessively low, for example, less than the threshold voltage, poor user experience such as shutdown may be caused. To ensure normal use of the electronic device, the voltage outputted to the load200needs to be adjusted back. In this way, the controller400controls the seventh switch Q7to be turned off, and controls the power conversion structure100to work in the foregoing voltage back-adjustment mode, to increase the voltage outputted to the load200to a value greater than the voltage of the battery300, thereby ensuring normal use of the electronic device10.

The present invention further provides an integrated circuit. Reference is made again to a schematic circuit diagram of an integrated circuit according to an embodiment of the present invention shown inFIG.12. As shown inFIG.12, the integrated circuit500includes: an input terminal din, configured to receive an input voltage Vin; a first switch Q1, connected between the input terminal din and a first top electrode plate node dh1, where the first switch Q1has a first control node dQ1; a second switch Q2, connected between the first top electrode plate node dh1and a battery terminal BAT, where the second switch Q2has a second control node dQ2, and the battery terminal BAT is configured to be connected to a battery300; a third switch Q3, connected between the battery terminal BAT and a first bottom electrode plate node dl1, where the third switch Q3has a third control node dQ3; a fourth switch Q4, connected between the first bottom electrode plate node dl1and a grounding terminal GND, where the fourth switch Q4has a fourth control node dQ4; a conversion node terminal SW, configured to provide an electric signal at a conversion node to an inductor L1, where the inductor L1is connected in series between the conversion node terminal SW and a system terminal SYS, and a capacitor C1is connected between the system terminal SYS and the grounding terminal GND; a fifth switch Q5, connected between the first top electrode plate node dh1and the conversion node terminal SW, where the fifth switch Q5has a fifth control node dQ5; a sixth switch Q6, connected between the first bottom electrode plate node dl1and the conversion node terminal SW, where the sixth switch Q6has a sixth control node dQ6; a seventh switch Q7, connected between the system terminal SYS and the battery terminal BAT, where the seventh switch Q7has a seventh control node dQ7; and a first flying capacitor terminal CHF1and a second flying capacitor terminal CHL1, configured to be respectively connected to a first terminal and a second terminal of a first flying capacitor Cf1, where the first flying capacitor terminal CHF1is connected to the first top electrode plate node dh1, and the second flying capacitor terminal CHL1is connected to the first bottom electrode plate node dl1.

As shown inFIG.12, the first switch Q1, the second switch Q2, the third switch Q3, the fourth switch Q4, and the first flying capacitor Cf1form a typical switch capacitor converter, and the first switch Q1, the fifth switch Q5, the sixth switch Q6, the fourth switch Q4, the inductor unit L1, and the first flying capacitor Cf1form a typical three-level buck converter. In this way, the integrated circuit shown inFIG.12may integrate the three-level buck converter and the switch capacitor converter. Switches of the switch capacitor converter and the three-level buck converter are reused, and the quantity of switches is reduced, so that the power conversion structure provided in the present invention has a small volume and low costs, and can have advantages of both the three-level buck converter and the switch capacitor converter, to achieve high efficiency of a whole process of charging the battery300of the electronic device while supplying power to the power consumption unit of the electronic device, that is, the load200connected to the system terminal SYS, and implement stable and reliable running of the electronic device. In addition, the first flying capacitor Cf1of the three-level buck converter and the switch capacitor converter is shared, which can further reduce the volume of the power conversion structure.

Referring toFIG.12again, in an embodiment of the present invention, a controller400is further included, and connected to the first control node to the seventh control node in the integrated circuit500, where the controller400is configured to: control, when the input terminal din receives an input voltage Vin, that is, the input terminal din is connected to an external power supply, a power conversion structure formed by the integrated circuit500, the inductor L1, the first flying capacitor Cf1, and the capacitor C1to work in a charge pump mode or a buck mode. Specifically, in an embodiment, a conversion ratio between an input voltage and an output voltage of the charge pump mode is N:1, where N is an integer greater than or equal to 2. The buck mode is used for forming the three-level buck converter.

Referring toFIG.12again, in an embodiment of the present invention, a controller400is further included, and connected to the first control node to the seventh control node in the integrated circuit5500, where the controller400is configured to: control, when no input voltage is inputted to the input terminal din, that is, the input terminal din receives no input voltage, or the input terminal din is not connected to an external power supply, or an input voltage Vin received by the input terminal din is zero volts, the battery terminal BAT to supply power to the system terminal SYS; and the controller400controls, in response to a case that a voltage of the system terminal SYS is reduced to a threshold voltage, the first switch Q1, the second switch Q2, the third switch Q3, the fourth switch Q4, the fifth switch Q5, and the sixth switch Q6to work to increase the voltage of the system terminal to a value greater than a voltage of the battery300. That is, when the battery300in the electronic device does not need to be charged, the adapter20is unplugged from the electronic device10, the controller400controls the seventh switch Q7to be turned on, and the battery300supplies power to the load200; and when the voltage outputted to the load200is excessively low, for example, less than the threshold voltage, poor user experience such as shutdown may be caused. To ensure normal use of the electronic device, the voltage outputted to the load200needs to be adjusted back. In this way, the controller400controls the seventh switch Q7to be turned off, and controls the power conversion structure100to work in the foregoing voltage back-adjustment mode, to increase the voltage outputted to the load200to a value greater than the voltage of the battery300, thereby ensuring normal use of the electronic device10. That the first switch Q1, the second switch Q2, the third switch Q3, the fourth switch Q4, the fifth switch Q5, and the sixth switch Q6work means that the first switch Q1, the second switch Q2, the third switch Q3, the fourth switch Q4, the fifth switch Q5, and the sixth switch Q6switch between being turned on and being turned off with a specific frequency. A specific working principle thereof is similar to those described inFIG.8,FIG.9a,FIG.9b, andFIG.9c. Details are not described herein again.

Reference is made again to a schematic circuit diagram of an integrated circuit according to another embodiment of the present invention shown inFIG.13. As shown inFIG.13, the integrated circuit500′ further includes: an eighth switch Q8, connected between the input terminal din and a second top electrode plate node dh2, where the eighth switch Q8has an eighth control node dQ8; a ninth switch Q9, connected between the second top electrode plate node dh2and the battery terminal BAT, where the ninth switch Q9has a ninth control node dQ9; a tenth switch Q10, connected between the battery terminal BAT and a second bottom electrode plate node d12, where the tenth switch Q10has a tenth control node dQ10; an eleventh switch Q11, connected between the second bottom electrode plate node dl2and the grounding terminal GND, where the eleventh switch Q11has an eleventh control node dQ11; and a third flying capacitor terminal CHF2and a fourth flying capacitor terminal CHL2, configured to be connected to a first terminal and a second terminal of a second flying capacitor Cf2, where the third flying capacitor terminal CHF2is connected to the second top electrode plate node dh2, and the fourth flying capacitor terminal CHL2is connected to the second bottom electrode plate node d12. In this way, the eighth switch Q8, the ninth switch Q9, the tenth switch Q10, the eleventh switch Q11, and the second flying capacitor Cf2form a second-phase switch capacitor converter, that is,FIG.13is integration of a two-phase switch capacitor converter and a three-level buck converter, thereby further improving the power level of the power conversion structure. Certainly, in an embodiment of the present invention, n second-phase switch capacitor converters connected in parallel shown inFIG.13may alternatively be included, where n is a positive integer, to implement a (n+1)-phase switch capacitor converter. The principle is stated explicitly with only two phases inFIG.13.

In an embodiment of actual application, when the second switch Q2and the third switch Q3are in the turned-off state, it is intended that the second switch Q2and the third switch Q3are completely cut off. In the foregoing embodiment, two parasitic diodes connected in anti-series back to back are connected in parallel at two terminals of the second switch Q2and the third switch Q3. Specifically, using the second switch Q2as an example, anodes of the two diodes are connected together, where a cathode of one diode is connected to the first terminal of the second switch Q2, and a cathode of the other diode is connected to the second terminal of the second switch Q2, so that the two diodes are connected in anti-series. The structure of the third switch Q3is the same as that of the second switch Q2. Details are not described herein again. Furthermore, in an embodiment of actual application, when the seventh switch Q7is in the turned-off state, a cutoff scenario (such as a ship mode) exists, that is, the seventh switch Q7may have the same structure as that of the second switch Q2. In another embodiment of the present invention, reference is made to a schematic circuit diagram of a power conversion structure according to another embodiment of the present invention shown inFIG.14. A substrate B of a second switch Q2is led out, and is connected to a first selection switch S11. A substrate B of a third switch Q3is led out, and is connected to a second selection switch S22. When working in a switch capacitor converter mode, the first selection switch S11is connected to a source of the second switch Q2(using an MOSFET as an example). When working in a three-level buck converter mode, the first selection switch S11is connected to a compensation voltage Vcomp, so that the second switch Q2is completely cut off. Similarly, when working in the switch capacitor converter mode, the second selection switch S22is connected to a source of the third switch Q3(using an MOSFET as an example). When working in the three-level buck converter mode, the second selection switch S22is connected to the compensation voltage Vcomp, so that the third switch Q3is completely cut off. In an embodiment of the present invention, the compensation voltage Vcomp is less than a voltage of a battery300. In an embodiment of the present invention, as shown inFIG.14, a substrate B of a seventh switch Q7is also led out.