Voltage conversion circuit, voltage converter, and voltage conversion method

Abstract

The application provides a voltage conversion circuit, a voltage converter and a voltage conversion method, and relates to the technical field of circuits.The voltage conversion circuit is characterized in that: in the voltage conversion circuit, one end of a first power device, one end of a second power device, one end of a third power device and one end of a fourth power device in a plurality of voltage conversion units are connected; the other end of the M first power devices and the other end of the N-1 second power devices in each voltage conversion unit are connected to one end of an energy storage unit; the other end of the M-1 third power devices and the other end of the N fourth power devices are connected to the other end of the energy storage unit; one end of a second input power device is connected to a voltage input end, one end of a second output power device is connected to a voltage output end, one end of a reference power device is further connected to a reference voltage end, and the other end of the second input power device, the second output power device and the reference power device is connected to the other end of the energy storage unit.The application can reduce charge sharing loss and improve voltage conversion efficiency at any conversion ratio.

Description

Technical Field

[0001] This invention relates to the field of circuit technology, and more specifically, to a voltage conversion circuit, a voltage converter, and a voltage conversion method. Background Technology

[0002] Switched capacitor voltage conversion circuits consist only of a switching transistor and a capacitor. Compared with traditional inductive switching power supply conversion circuits, switched capacitor voltage conversion circuits have advantages such as light weight, small size, and high energy density.

[0003] Traditional switched capacitor voltage conversion circuits have low efficiency due to charge sharing losses. By implementing a step change in capacitor voltage through an intermediate voltage rail in the voltage conversion circuit, the charge sharing losses during capacitor charging and discharging are reduced.

[0004] However, this method is only most efficient when the conversion ratio between the input and output voltages is at the optimal conversion ratio. When the conversion ratio is not optimal, the charge sharing loss is still large and the voltage conversion efficiency is still very low. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of the prior art by providing a voltage conversion circuit, a voltage converter, and a voltage conversion method, so as to reduce charge sharing losses and improve voltage conversion efficiency at any conversion ratio.

[0006] To achieve the above objectives, the technical solutions adopted in the embodiments of this application are as follows:

[0007] In a first aspect, embodiments of this application provide a voltage conversion circuit, which includes: 2M+2N+1 voltage conversion units, a voltage input terminal, a voltage output terminal, and a reference voltage terminal; wherein M and N are integers greater than or equal to 1;

[0008] Each voltage conversion unit includes: M first power devices, N-1 second power devices, an energy storage unit, a first input power device, a first output power device, M-1 third power devices, N fourth power devices, a second input power device, a second output power device, and a reference power device;

[0009] In the 2M+2N+1 voltage conversion units, one end of the first power device is connected, and one end of the second power device in the 2M+2N+1 voltage conversion units is connected. The other ends of the M first power devices and the N-1 second power devices in each voltage conversion unit are both connected to one end of the energy storage unit. One end of the first input power device is connected to the voltage input terminal, one end of the first output power device is connected to the voltage output terminal, and the other ends of the first input power device and the first output power device are both connected to one end of the energy storage unit.

[0010] One end of the third power device in the 2M+2N+1 voltage conversion units is connected, and one end of the fourth power device in the 2M+2N+1 voltage conversion units is connected. The other ends of the M-1 third power devices and the N fourth power devices in each voltage conversion unit are all connected to the other end of the energy storage unit. One end of the second input power device is connected to the voltage input terminal, one end of the second output power device is connected to the voltage output terminal, and one end of the reference power device is also connected to the reference voltage terminal. The other ends of the second input power device, the second output power device, and the reference power device are all connected to the other end of the energy storage unit.

[0011] Optionally, if the preset output voltage of the voltage conversion circuit is less than the preset input voltage, and the difference between the preset input voltage and the preset output voltage is greater than the preset voltage difference, all M first power devices are activated, the number of activated N-1 second power devices is greater than or equal to 1, all M-1 third power devices are not activated, and the number of activated N fourth power devices is less than N.

[0012] The first input power device, the first output power device, the second output power device, and the reference power device are activated.

[0013] Optionally, if the preset output voltage of the voltage conversion circuit is less than the preset input voltage, and the difference between the preset input voltage and the preset output voltage is less than the preset voltage difference, the number of activated M first power devices is less than M, all N-1 second power devices are not activated, the number of activated M-1 third power devices is greater than or equal to 1, and all N fourth power devices are activated.

[0014] The first input power device, the first output power device, the second output power device, and the reference power device are activated.

[0015] Optionally, if the preset output voltage of the voltage conversion circuit is greater than the preset input voltage, and the difference between the preset output voltage and the preset input voltage is greater than the preset voltage difference, all M first power devices are activated, the number of activated N-1 second power devices is greater than or equal to 1, all M-1 third power devices are not activated, and the number of activated N fourth power devices is less than N.

[0016] The first input power device, the first output power device, the second input power device, and the reference power device are activated.

[0017] Optionally, if the preset output voltage of the voltage conversion circuit is greater than the preset input voltage, and the difference between the preset output voltage and the preset input voltage is less than the preset voltage difference, the number of activated M first power devices is less than M, all N-1 second power devices are not activated, the number of activated M-1 third power devices is greater than or equal to 1, and all N fourth power devices are activated.

[0018] The first input power device, the first output power device, the second input power device, and the reference power device are activated.

[0019] Secondly, embodiments of this application also provide a voltage converter, including: a control unit and any of the voltage conversion circuits described in the first aspect above;

[0020] The control unit is connected to the control terminals of each power device in the 2M+2N+1 voltage conversion units of the voltage conversion circuit.

[0021] Optionally, the control unit includes: a conversion ratio matching unit, a control signal generation unit, and a one-hot code generation unit;

[0022] The input terminal of the conversion ratio matching unit receives a preset input voltage signal and a preset output voltage signal. The output terminal of the conversion ratio matching unit and the one-hot code generation unit are connected to the input terminal of the control signal generation unit. The output terminal of the control signal generation unit is connected to the control terminal of each power device.

[0023] Optionally, the control unit further includes: an error amplification unit and a voltage-controlled oscillation unit;

[0024] The input terminal of the error amplification unit receives the output sampling voltage and the reference voltage. The output terminal of the error amplification unit is connected to the input terminal of the voltage-controlled oscillator unit, and the output terminal of the voltage-controlled oscillator unit is connected to the one-hot code generation unit.

[0025] Optionally, the voltage converter further includes a level shifting unit connected between the control unit and the control terminals of each power device.

[0026] Thirdly, embodiments of this application also provide a voltage conversion method, applied to a control unit in a voltage converter as described in any of the first aspects, the method comprising:

[0027] 2M+2N+1 control signals are generated based on the preset voltage conversion ratio;

[0028] According to the control signal, each power device in the 2M+2N+1 voltage conversion units is controlled to conduct in different phases, so that the voltage conversion circuit outputs an output voltage that meets the preset voltage conversion ratio.

[0029] The beneficial effects of this application are:

[0030] This application provides a voltage conversion circuit, a voltage converter, and a voltage conversion method. With the number of capacitors remaining constant, the number of power devices on the upper and lower plates is increased. The upper plate includes M first power devices and N-1 second power devices, and the lower plate includes M-1 third power devices and N fourth power devices. This allows the number of virtual voltage rails on the upper and lower plates to be increased or decreased by the number of activated power devices. This ensures that the step voltage steps on the upper and lower plates are equal at any conversion ratio, resulting in very low charge sharing losses at any conversion ratio and improved voltage conversion efficiency. Attached Figure Description

[0031] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This is a schematic diagram of an existing voltage conversion circuit;

[0033] Figure 2 A schematic diagram illustrating the effect of an existing voltage conversion circuit operating at its optimal conversion ratio.

[0034] Figure 3 This is a schematic diagram illustrating the effect of an existing voltage conversion circuit operating at a non-optimal conversion ratio.

[0035] Figure 4 This is a schematic diagram of the voltage conversion circuit provided in the embodiments of this application;

[0036] Figure 5 Working principle of the voltage conversion circuit provided in the embodiments of this application Figure 1 ;

[0037] Figure 6 This is a schematic diagram illustrating the effect of the high voltage reduction conversion ratio provided in the embodiments of this application;

[0038] Figure 7 Working principle of the voltage conversion circuit provided in the embodiments of this application Figure 2 ;

[0039] Figure 8 This is a schematic diagram illustrating the effect of the low voltage reduction conversion ratio provided in the embodiments of this application;

[0040] Figure 9 Working principle of the voltage conversion circuit provided in the embodiments of this application Figure 3 ;

[0041] Figure 10 This is a schematic diagram illustrating the effect of the high boost conversion ratio provided in the embodiments of this application;

[0042] Figure 11 Working principle of the voltage conversion circuit provided in the embodiments of this application Figure 4 ;

[0043] Figure 12 This is a schematic diagram illustrating the effect of the low conversion ratio provided in the embodiments of this application;

[0044] Figure 13 The curves showing the relationship between input resistance, frequency, and M are provided in the embodiments of this application.

[0045] Figure 14 A schematic diagram of the structure of the voltage converter provided in the embodiments of this application. Figure 1 ;

[0046] Figure 15 A schematic diagram of the structure of the voltage converter provided in the embodiments of this application. Figure 2 ;

[0047] Figure 16 This is a schematic flowchart of the voltage conversion method provided in an embodiment of this application. Detailed Implementation

[0048] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments.

[0049] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0050] In the description of this application, it should be noted that if the terms "upper", "lower", etc. appear to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship that the product of this application is usually placed in, it is only for the convenience of describing this application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0051] Furthermore, the terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Additionally, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0052] It should be noted that, where there is no conflict, the features in the embodiments of this application can be combined with each other.

[0053] Please refer to Figure 1 This is a schematic diagram of an existing voltage conversion circuit, such as... Figure 1 As shown, the existing voltage conversion circuit includes: 2M+2N+1 voltage conversion units, and the voltage input terminal V IN Voltage output terminal V OUT and the reference voltage terminal V SS .

[0054] Each voltage conversion unit includes: M upper plate power devices, N lower plate power devices, upper plate input power devices, upper plate output power devices, lower plate output power devices, and lower plate output power devices.

[0055] In this system, one end of each of the M upper plate power devices in the multiple voltage conversion units is connected to the corresponding upper plate middle voltage terminal V. T1 -V TMOne end of each of the N lower plate power devices in the multiple voltage conversion units is connected, and their connection points are respectively the corresponding lower plate middle voltage terminals V. B1 -V BN The other ends of the M upper plate power devices are connected to the upper plate of the energy storage unit, and the other ends of the N lower plate power devices are connected to the lower plate of the energy storage unit.

[0056] One end of the upper plate input power device is connected to the input voltage terminal V. IN One end of the upper plate output power device is connected to the output voltage terminal V. OUT The other end of the upper plate input power device and the other end of the upper plate output power device are connected to the upper plate of the energy storage unit.

[0057] One end of the lower plate output power device is connected to the output voltage terminal V. OUT One end of the lower electrode reference power device is connected to the reference voltage terminal V. SS The other end of the lower plate output power device and the other end of the lower plate reference power device are connected to the lower plate of the energy storage unit.

[0058] In order to pass the voltage terminal V at the middle of the upper plate T1 -V TM and the voltage terminal V between the lower electrode plates B1 -V BN To achieve direct charge transfer between energy storage units, the energy storage units on every two voltage conversion units need to be connected through an intermediate voltage terminal for direct charge transfer. Therefore, based on the intermediate voltage terminal V of the upper plate... T1 -V TM and the voltage terminal V between the lower electrode plates B1 -V BN Based on the quantity, the number of energy storage units is determined to be 2M+2N+1, which means 2M+2N+1 voltage conversion units are needed.

[0059] Please refer to Figure 2 This is a schematic diagram illustrating the effect of an existing voltage conversion circuit operating at its optimal conversion ratio, such as... Figure 2 As shown, the power devices included in each energy storage unit connect the upper plate of the energy storage unit to the input voltage terminal V. IN Output voltage terminal V OUT Or the voltage terminal V in the middle of the upper electrode plate Ti The voltage terminal V at the middle of the upper electrode plate T1 -V TM The energy storage unit is provided with M virtual voltage rails for voltage stepping, and the voltage step of the M virtual voltage rails is ΔV. T The lower electrode is connected to the voltage terminal V in the middle of the lower electrode. Bj Output voltage terminal V OUT Or reference voltage terminal V SSThe voltage terminal V at the middle of the lower electrode plate B1 -V BN The energy storage unit is provided with N virtual voltage rails for voltage stepping, and the voltage step of the N virtual voltage rails is ΔV. B These M+N virtual voltage rails enable step changes in the upper plate voltage and the lower plate voltage of the energy storage unit.

[0060] Depending on the values ​​of M and N, ΔV can be made such that the difference between the input voltage and the output voltage is equal to a preset voltage difference. T and ΔV B When the input and output voltages are approximately equal, the ratio of the difference between the input and output voltages to the difference between the output voltage and the reference voltage is the optimal conversion ratio. In this case, the continuously variable switched capacitor voltage converter circuit can achieve the optimal efficiency.

[0061] Please refer to Figure 3 This is a schematic diagram illustrating the effect of an existing voltage conversion circuit operating at a non-optimal conversion ratio, such as... Figure 3 As shown, taking buck converter as an example, when the difference between the input voltage and the output voltage is greater than the preset voltage difference, the voltage step range required by the upper plate increases, and the voltage step range required by the lower plate decreases. Since M and N are fixed in the existing technology, the voltage step of the M virtual voltage rails is increased by ΔV. T A voltage step ΔV much larger than N virtual voltage rails B This results in significant charge sharing losses, reducing voltage conversion efficiency.

[0062] Based on the problems existing in the prior art, this application proposes to provide a voltage conversion circuit, a voltage converter, and a voltage conversion method. With the number of capacitors remaining constant, the number of power devices on the upper and lower plates is increased. The upper plate includes M first power devices and N-1 second power devices, and the lower plate includes M-1 third power devices and N fourth power devices. This allows the number of virtual voltage rails on the upper and lower plates to be increased or decreased by the number of activated power devices. This ensures that the step voltage steps of the upper and lower plates are equal at any conversion ratio, guaranteeing very low charge sharing losses at any conversion ratio and improving voltage conversion efficiency.

[0063] Please refer to Figure 4 The diagram below is a schematic representation of the voltage conversion circuit provided in an embodiment of this application. Figure 4 As shown, the voltage conversion circuit includes: 2M+2N+1 voltage conversion units, and a voltage input terminal V. IN Voltage output terminal V OUT and the reference voltage terminal V SS ; where M and N are integers greater than or equal to 1.

[0064] Each voltage conversion unit includes: M first power devices Q T1 -Q TM N-1 second power devices Q TB2 -Q TBN Energy storage unit, first input power device Q IN1 First output power device Q OUT1 M-1 third power devices Q BT1 -Q BTM-1 N fourth power devices Q B1 -Q BN Second input power device Q IN2 Second output power device Q OUT2 and reference power device Q SS .

[0065] The first power device Q in 2M+2N+1 voltage conversion units T1 -Q TM One end is connected to the second power device Q in the 2M+2N+1 voltage conversion units. TB2 -Q TBN One end is connected, and each voltage conversion unit contains M first power devices Q. T1 -Q TM The other end and N-1 second power devices Q TB2 -Q TBN The other end is connected to one end of the energy storage unit; the first input power device Q IN1 One end is connected to the voltage input terminal V IN The first output power device Q OUT1 One end is connected to the voltage output terminal V OUT The first input power device Q IN1 and the first output power device Q OUT1 The other end of each is connected to one end of the energy storage unit.

[0066] The third power device Q in 2M+2N+1 voltage conversion units BT1 -Q BTM-1 One end is connected, and the fourth power device Q in the 2M+2N+1 voltage conversion units B1 -Q BN One end is connected, and each voltage conversion unit contains M-1 third power devices Q. BT1 -Q BTM-1 The other end and N fourth power devices Q B1 -Q BN The other end is connected to the other end of the energy storage unit; the second input power device Q IN2 One end is connected to the voltage input terminal V INThe second output power device Q OUT2 One end is connected to the voltage output terminal V OUT Reference power device Q SS One end is also connected to the reference voltage terminal V. SS The second input power device Q IN2 Second output power device Q OUT2 and reference power device Q SS The other end of each is connected to the other end of the energy storage unit.

[0067] In this embodiment, based on the M first power devices on the upper electrode plate, N-1 second power devices are added to provide N-1 additional voltage rails available for step transitions on the upper electrode plate; based on the N fourth power devices on the lower electrode plate, M-1 third power devices are added to provide M-1 additional voltage rails available for step transitions on the lower electrode plate.

[0068] Based on the input and output voltages, the number of voltage rails required for the upper and lower plates can be determined, and the corresponding number of power devices can be turned on according to the required number of voltage rails.

[0069] For example, if the upper plate requires at least M+1 step voltage rails and the lower plate requires less than N step voltage rails, then M first power devices and at least one second power device are activated, less than N fourth power devices are activated, and M-1 third power devices are not activated.

[0070] If the upper plate requires less than M level step voltage rails and the lower plate requires at least N+1 level step voltage rails, then control the activation of less than M first power devices, deactivate all N-1 second power devices, and activate at least one third power device and N fourth power devices.

[0071] Of course, this scheme can also achieve the optimal conversion ratio when the upper plate requires M-level step voltage rails and the lower plate requires N-level step voltage rails, by controlling the activation of M first power devices and N fourth power devices.

[0072] In some embodiments, the energy storage unit may be a flying capacitor.

[0073] In one embodiment, the first power device and the fourth power device may be P-channel transistors, and the second power device and the third power device may be N-channel transistors.

[0074] It should be noted that the reason for adding N-1 second power devices to the upper electrode and M-1 third power devices to the lower electrode is that the total number of power devices activated by the upper and lower electrodes is M+N, and at least one power device is activated by each electrode. Therefore, when only one power device is activated by the upper electrode, the lower electrode needs to activate M-1 more power devices on top of the existing N power devices to ensure that the total number of power devices activated by the upper and lower electrodes is M+N. Similarly, when only one power device is activated by the lower electrode, the upper electrode needs to activate N-1 more power devices on top of the existing M power devices to ensure that the total number of power devices activated by the upper and lower electrodes is M+N.

[0075] After determining the activation of the power devices corresponding to the required step number, multiple control signals are used to control the activated power devices in multiple voltage conversion units to conduct, so that the energy storage units in multiple voltage conversion units work sequentially in different phases. Based on the voltage rails connected to the two ends of the energy storage unit in each phase, the voltage across the energy storage unit is determined to be the voltage between the two connected voltage rails.

[0076] It should be noted that, due to the input voltage terminal V IN Output voltage terminal V OUT and reference voltage terminal V SS Since the actual physical components are connected respectively, the input voltage terminal V... IN Output voltage terminal V OUT and reference voltage terminal V SS A real voltage rail is provided; while the connection terminals between the power devices in multiple voltage conversion units provide a virtual voltage rail, and the voltage on the virtual voltage rail is achieved through soft charging of the voltage conversion circuit.

[0077] In some embodiments, if the voltage conversion circuit in this embodiment is applied to a photovoltaic energy harvesting scenario, then the input voltage terminal V IN Used to receive voltage acquired from a data acquisition source, output voltage terminal V OUT It can be connected to a load or battery, with reference voltage V. SS This can serve as a reference.

[0078] In one possible implementation, if the preset output voltage of the voltage conversion circuit is less than the preset input voltage, and the difference between the preset input voltage and the preset output voltage is greater than the preset voltage difference, then the M first power devices Q T1 -Q TM All activated, N-1 second power devices Q TB2 -Q TBN The number of activated devices is greater than or equal to 1, M-1 third power devices Q BT1 -Q BTM-1All are inactive, N fourth power devices Q B1 -Q BN The number of activated devices is less than N; the first input power device Q IN1 First output power device Q OUT1 Second output power device Q OUT2 and reference power device Q SS activation.

[0079] Please refer to Figure 5 The working principle of the voltage conversion circuit provided in the embodiments of this application. Figure 1 ,like Figure 5 As shown, when the preset output voltage is less than the preset input voltage, and the difference between the preset input voltage and the preset output voltage is greater than the preset voltage difference, the conversion value between the preset input voltage and the preset output voltage is relatively large. The level conversion circuit is used to realize the voltage conversion with a large step-down conversion ratio. The number of step voltage levels required for the upper plate of the energy storage unit is greater than M, and the number of step voltage levels required for the lower plate is less than N.

[0080] Therefore, M first power devices Q T1 -Q TM All are activated, and from N-1 second power devices Q TB2 -Q TBN Select the second power device Q by subtracting the required step number from M. TBk+1 -Q TBN M-1 third power devices Q BT1 -Q BTM-1 All are deactivated, from N fourth power devices Q B1 -Q BN Select the fourth power device Q with the required step number. B1 -Q BK .

[0081] In the buck configuration, the first input power device Q IN1 First output power device Q OUT1 Second output power device Q OUT2 and reference power device activation Q SS It is activated so that the upper plate of the energy storage unit can be connected to V. IN1 Or V OUT1 The lower electrode can be connected to V. OUT2 Or V SS .

[0082] It should be noted that activated power devices refer to power devices that are selected to work during the level transition process, that is, power devices that can be turned on or off according to the control signal. Inactive power devices refer to power devices that do not need to work during the level transition process, that is, power devices that are always in the off state.

[0083] After the activated power device is selected, different power devices on each voltage conversion unit are turned on by controlling them. Only one power device on each voltage conversion unit is turned on at any given time. If two interconnected power devices distributed on two voltage conversion units are turned on, the upper or lower plate of each energy storage unit will perform a voltage step.

[0084] It should be noted that the power devices that are turned on mentioned here do not include the first input power device Q. IN1 First output power device Q OUT1 Second output power device Q OUT2 and reference power device activation Q SS The first input power device Q IN1 First output power device Q OUT1 Second output power device Q OUT2 and reference power device activation Q SS Its conduction state needs to be controlled separately.

[0085] For example, please refer to Figure 6 This is a schematic diagram illustrating the effect of the high voltage reduction conversion ratio provided in the embodiments of this application, such as... Figure 6 As shown, since the number of power devices conducting on the upper plate is greater than M and the number of power devices conducting on the lower plate is less than N, the number of voltage steps on the upper plate is greater than M and the number of voltage steps on the lower plate is less than N. Furthermore, the voltage step size of the upper plate is ΔV. T The voltage step ΔV of the lower plate B equal.

[0086] like Figure 6 As shown, taking phase Φ1 as an example, the voltage across the first energy storage unit is V. B1 The first output power device V on the upper plate of the first energy storage unit OUT1 When the circuit is turned on, the second power device Q on the lower electrode plate... B1 When the first energy storage power source collides with the voltage of the second energy storage unit, the voltage across the first energy storage power source jumps upward to V. B2 At phase Φ2, the first output power device V on the upper plate of the first energy storage unit OUT1 When the circuit is turned on, the second power device Q on the lower electrode plate... B2 Conduction.

[0087] Among them, the second energy storage unit that collides with the first energy storage unit in voltage is the first input power device V on the upper plate. IN1 When the circuit is turned on, the second power device Q on the lower electrode plate... B1 The conducting energy storage unit, through two conducting second power devices QB1 Connect the lower plates of the first and second energy storage units. The charge in the second energy storage unit is transferred to the first energy storage unit, causing the voltage of the first energy storage unit to step upward and the voltage of the second energy storage unit to step downward. The stepping methods for other phases are the same and will not be described in detail here.

[0088] It should be noted that the initial phase difference between each energy storage unit is 2. For example, if the first energy storage unit initially operates at phase Φ1, then the second energy storage unit initially operates at phase Φ3, and so on.

[0089] In one possible implementation, if the preset output voltage of the voltage conversion circuit is less than the preset input voltage, and the difference between the preset input voltage and the preset output voltage is less than the preset voltage difference, then the M first power devices Q T1 -Q TM The number of activated devices is less than M, N-1 second power devices Q TB2 -Q TBN All are inactive, M-1 third power devices Q BT1 -Q BTM-1 The number of activated devices is greater than or equal to 1, and N fourth power devices Q B1 -Q BN All activated; first input power device Q IN1 First output power device Q OUT1 Second output power device Q OUT2 and reference power device activation Q SS .

[0090] Please refer to Figure 7 The working principle of the voltage conversion circuit provided in the embodiments of this application. Figure 2 ,like Figure 7 As shown, when the preset output voltage is less than the preset input voltage, and the difference between the preset input voltage and the preset output voltage is less than the preset voltage difference, the conversion value between the preset input voltage and the preset output voltage is small. The level conversion circuit is used to realize the voltage conversion with a small step-down conversion ratio. The number of step voltage levels required for the upper plate of the energy storage unit is less than M, and the number of step voltage levels required for the lower plate is greater than N.

[0091] Therefore, from M first power devices Q T1 -Q TM Select the first power device Q with the required step number. Tj -Q TM N-1 second power devices Q TB2 -Q TBN All are deactivated, from M-1 third power devices Q BT1 -Q BTM-1 Select the second power device Q, which is the required step number minus N.TB1 -Q TBj-1 N fourth power devices Q B1 -Q BN All activated.

[0092] In the buck configuration, the first input power device Q IN1 First output power device Q OUT1 Second output power device Q OUT2 and reference power device activation Q SS It is activated so that the upper plate of the energy storage unit can be connected to V. IN Or V OUT The lower electrode can be connected to V. OUT Or V SS .

[0093] For example, please refer to Figure 8 This is a schematic diagram illustrating the effect of the low voltage reduction conversion ratio provided in the embodiments of this application, such as... Figure 8 As shown, since the number of power devices conducting on the upper plate is less than M and the number of power devices conducting on the lower plate is greater than N, the number of voltage steps on the upper plate is less than M and the number of voltage steps on the lower plate is greater than N. Furthermore, the voltage step size of the upper plate is ΔV. T The voltage step ΔV of the lower plate B equal.

[0094] The voltage step process with a small step-down conversion ratio is similar to the voltage step process with a large step-down conversion ratio described above, and will not be elaborated upon in this embodiment.

[0095] In one possible implementation, if the preset output voltage of the voltage conversion circuit is greater than the preset input voltage, and the difference between the preset output voltage and the preset input voltage is greater than the preset voltage difference, then the M first power devices Q T1 -Q TM All activated, N-1 second power devices Q TB2 -Q TBN The number of activated devices is greater than or equal to 1, M-1 third power devices Q BT1 -Q BTM-1 All are inactive, N fourth power devices Q B1 -Q BN The number of activated devices is less than N; the first input power device Q IN1 First output power device Q OUT1 Second input power device Q IN1 and reference power device activation V SS .

[0096] Please refer to Figure 9 The working principle of the voltage conversion circuit provided in the embodiments of this application. Figure 3 ,like Figure 9 As shown, when the preset output voltage is greater than the preset input voltage, and the difference between the preset output voltage and the preset input voltage is greater than the preset voltage difference, the conversion value between the preset input voltage and the preset output voltage is relatively large. The level conversion circuit is used to realize the voltage conversion with a large conversion ratio. The number of step voltage levels required for the upper plate of the energy storage unit is greater than M, and the number of step voltage levels required for the lower plate is less than N.

[0097] Therefore, M first power devices Q T1 -Q TM All are activated, and from N-1 second power devices Q TB2 -Q TBN Select the second power device Q by subtracting the required step number from M. TBk+1 -Q TBN M-1 third power devices Q BT1 -Q BTM-1 All are deactivated, from N fourth power devices Q B1 -Q BN Select the fourth power device Q with the required step number. B1 -Q BK .

[0098] In boost mode, the first input power device Q IN1 First output power device Q OUT1 Second input power device Q IN2 and reference power device activation Q SS It is activated so that the upper plate of the energy storage unit can be connected to V. IN Or V OUT The lower electrode can be connected to V. IN Or V SS .

[0099] For example, please refer to Figure 10 This is a schematic diagram illustrating the effect of the high conversion ratio provided in the embodiments of this application, such as... Figure 10 As shown, since the number of power devices conducting on the upper plate is greater than M and the number of power devices conducting on the lower plate is less than N, the number of voltage steps on the upper plate is greater than M and the number of voltage steps on the lower plate is less than N. Furthermore, the voltage step size of the upper plate is ΔV. T The voltage step ΔV of the lower plate B equal.

[0100] like Figure 10 As shown, at phase Φ1, the voltage across the first energy storage unit is V. BK The first input power device V on the upper plate of the first energy storage unit IN1 When the circuit is turned on, the second power device Q on the lower electrode plate... BKWhen the first energy storage power source collides with the voltage of the second energy storage unit, the voltage across the first energy storage power source jumps downwards to V. BK-1 At phase Φ2, the first input power device V on the upper plate of the first energy storage unit IN1 When the circuit is turned on, the second power device Q on the lower electrode plate... BK-1 Conduction.

[0101] Among them, the second energy storage unit that collides with the first energy storage unit in voltage is the first output power device V on the upper plate. OUT1 When the circuit is turned on, the second power device Q on the lower electrode plate... BK Conduction occurs through two conducting second power devices Q. BK Connect the lower plates of the first and second energy storage units. The charge in the first energy storage unit is transferred to the second energy storage unit, causing the voltage of the first energy storage unit to step downwards and the voltage of the second energy storage unit to step upwards. The stepping methods for other phases are the same and will not be described in detail here.

[0102] In one possible implementation, if the preset output voltage of the voltage conversion circuit is greater than the preset input voltage, and the difference between the preset output voltage and the preset input voltage is less than the preset voltage difference, then the M first power devices Q T1 -Q TM The number of activated devices is less than M, and there are N-1 second power devices Q. TB2 -Q TBN All are inactive, M-1 third power Q BT1 -Q BTM-1 The number of activated devices is greater than or equal to 1, and N fourth power devices Q B1 -Q BN All activated; first input power device Q IN1 First output power device Q OUT1 Second input power device Q IN2 and reference power device Q SS activation.

[0103] Please refer to Figure 11 The working principle of the voltage conversion circuit provided in the embodiments of this application. Figure 4 ,like Figure 11 As shown, when the preset output voltage is greater than the preset input voltage, and the difference between the preset output voltage and the preset input voltage is less than the preset voltage difference, the conversion value between the preset input voltage and the preset output voltage is small. The level conversion circuit is used to realize the voltage conversion with a small conversion ratio. The number of step voltage levels required for the upper plate of the energy storage unit is less than M, and the number of step voltage levels required for the lower plate is greater than N.

[0104] Therefore, from M first power devices Q T1 -Q TMSelect the first power device Q with the required step number. Tj -Q TM N-1 second power devices Q TB2 -Q TBN All are deactivated, from M-1 third power devices Q BT1 -Q BTM-1 Select the second power device Q, which is the required step number minus N. TB1 -Q TBj-1 N fourth power devices Q B1 -Q BN All activated.

[0105] In boost mode, the first input power device Q IN1 First output power device Q OUT1 Second input power device Q IN2 and reference power device activation Q SS It is activated so that the upper plate of the energy storage unit can be connected to V. IN Or V OUT The lower electrode can be connected to V. IN Or V SS .

[0106] For example, please refer to Figure 12 This is a schematic diagram illustrating the effect of the low conversion ratio boost provided in the embodiments of this application, as shown below. Figure 12 As shown, since the number of power devices conducting on the upper plate is less than M and the number of power devices conducting on the lower plate is greater than N, the number of voltage steps on the upper plate is less than M and the number of voltage steps on the lower plate is greater than N. Furthermore, the voltage step size of the upper plate is ΔV. T The voltage step ΔV of the lower plate B equal.

[0107] The voltage step process with a small boost conversion ratio is similar to the voltage step process with a large boost conversion ratio described above, and will not be repeated here.

[0108] It should be noted that the terms "larger conversion value" and "smaller conversion value" in the above embodiments are relative to... Figure 2 The preset conversion value between the input voltage and the output voltage shown indicates that when the preset conversion value between the preset input voltage and the preset output voltage in each embodiment is greater than... Figure 2 The preset conversion value between the input voltage and the output voltage shown indicates that a larger conversion value means the level conversion circuit achieves a high conversion ratio for voltage conversion; when the preset conversion value between the preset input voltage and the preset output voltage in each embodiment is smaller... Figure 2 The preset conversion value between the input voltage and the output voltage shown is a small conversion value, and the level conversion circuit achieves a voltage conversion with a small conversion ratio.

[0109] The voltage conversion circuit provided in the above embodiment, with the number of capacitors remaining unchanged, increases the number of power devices on the upper and lower plates. The upper plate includes M first power devices and N-1 second power devices, and the lower plate includes M-1 third power devices and N fourth power devices. This allows the number of virtual voltage rails on the upper and lower plates to be increased or decreased by the number of activated power devices. This ensures that the step voltage step of the upper plate and the step voltage step of the lower plate are equal at any conversion ratio, resulting in very low charge sharing loss at any conversion ratio and improved voltage conversion efficiency.

[0110] Furthermore, the voltage conversion circuit provided in the above embodiments can achieve both boost and buck conversion by simply adding a second input power device and changing the charging and discharging sequence of the capacitor. In both boost and buck conversion, the step voltage step of the upper plate and the step voltage step of the lower plate can be guaranteed to be equal, resulting in very low charge sharing loss at any conversion ratio and improving voltage conversion efficiency.

[0111] Please refer to Figure 13 The curve showing the relationship between input resistance, frequency, and M provided in the embodiments of this application is as follows: Figure 13 As shown, since the step number M of the upper plate in the traditional method is a fixed value, the range of the input resistance is limited. However, in this embodiment, the step number M of the upper plate is adjustable, which allows the input resistance to have a wider input range, so as to be used for tracking of a wider range of maximum power point tracking (MPPT).

[0112] Based on the voltage conversion circuit provided in the above embodiments, this application also provides a voltage converter.

[0113] Please refer to Figure 14 This is a schematic diagram of the structure of the voltage converter provided in the embodiments of this application. Figure 1 ,like Figure 14 As shown, the voltage converter includes a control unit 10 and a voltage conversion circuit 20. The control unit is connected to the control terminals of each power device in the 2M+2N+1 voltage conversion units of the voltage conversion circuit.

[0114] In this embodiment, the control unit 10 receives a preset input voltage signal and a preset output voltage signal, and determines whether the voltage conversion circuit 20 is used for boosting or bucking, and the voltage conversion ratio, based on the preset input voltage signal and the preset output voltage signal. Based on the boosting or bucking result and the voltage conversion ratio, the control unit 10 determines the working phase of the energy storage unit on each voltage conversion unit, and generates two control signals for each voltage conversion unit according to the working phase. One control signal is used to control the first input power device, the first output power device, the second input power device, the second output power device, or the reference power device to turn on, and the other control signal is used to control one of the first power device, the second power device, the third power device, and the fourth power device to turn on. When the target power device of each energy storage unit is turned on, it connects the upper or lower plate of the corresponding energy storage unit, causing a voltage step in the energy storage unit. In the next phase, the control signal switches to turn on another target power device.

[0115] The control unit 10 determines the power device to be activated based on the preset input voltage signal and the preset output voltage signal. This can be referred to in the embodiment of the voltage conversion circuit described above, and will not be repeated here.

[0116] In one possible implementation, please refer to Figure 15 This is a schematic diagram of the structure of the voltage converter provided in the embodiments of this application. Figure 2 ,like Figure 15 As shown, the control unit 10 includes: a conversion ratio matching unit 11, a control signal generation unit 12, and a one-hot code generation unit 13.

[0117] The input terminal of the conversion ratio matching unit 11 receives a preset input voltage signal and a preset output voltage signal. The output terminal of the conversion ratio matching unit 11 and the one-hot code generation unit 13 are connected to the input terminal of the control signal generation unit 12. The output terminal of the control signal generation unit 12 is connected to the control terminal of each power device.

[0118] In this embodiment, the conversion ratio matching unit 11 receives a preset input voltage signal and a preset output voltage signal, determines whether the voltage conversion circuit 20 is used for boosting or bucking, and the voltage conversion ratio based on the preset input voltage signal and the preset output voltage signal, and sends the boost conversion ratio or buck conversion ratio to the control signal generation unit 12.

[0119] The unique hot code generation unit 13 is used to provide multiple unique hot codes for the control signal generation unit 12. Each unique hot code is used to indicate the working phase of the energy storage unit in a level conversion unit. The control signal generation unit 12 generates two control signals for each circuit conversion unit according to the boost or buck result, the voltage conversion ratio and the working phase of each energy storage unit.

[0120] In one possible embodiment, such as Figure 15 As shown, the control unit 10 also includes an error amplification unit 14 and a voltage-controlled oscillation unit 15.

[0121] The input terminal of the error amplifier unit 14 receives the output sampling voltage and the reference voltage. The output terminal of the error amplifier unit 14 is connected to the input terminal of the voltage-controlled oscillator unit 15. The output terminal of the voltage-controlled oscillator unit 15 is connected to the one-hot code generation unit 13.

[0122] In this embodiment, the positive input terminal of the error amplification unit 14 is connected to the voltage reference signal, and the negative input terminal is connected to the sampling resistor at the output terminal to receive the output sampling voltage. The error amplification unit 14 is used to amplify the error of the output voltage of the level converter. If the output sampling voltage is greater than the voltage reference signal, the error amplification unit 14 outputs a high-level signal. If the output sampling voltage is less than the voltage reference signal, the error amplification unit 14 outputs a low-level signal.

[0123] The input terminal of the voltage-controlled oscillator unit 15 is connected to the output terminal of the error amplifier unit 14. The voltage-controlled oscillator unit 15 generates an oscillation frequency based on the error amplification signal. The output terminal of the voltage-controlled oscillator unit 15 is connected to the hot-code generation unit 13. The hot-code generation unit 13 is used to determine the output frequency of the hot code based on the oscillation frequency. If the error amplifier unit 14 outputs a low-level signal, the high oscillation frequency output by the voltage-controlled oscillator unit 15 will increase the frequency of the hot code output by the hot-code generation unit 13. If the error amplifier unit 14 outputs a high-level signal, the low oscillation frequency output by the voltage-controlled oscillator unit 15 will decrease the frequency of the hot code output by the hot-code generation unit 13.

[0124] In one possible embodiment, such as Figure 15 As shown, the control unit 10 also includes a level shifting unit 16, which is connected between the control signal generation unit 12 and the control terminals of each power device.

[0125] In this embodiment, the level shifting unit is connected between the control signal generation unit 12 and the control terminals of each power device to shift the level of the control signal so that the shifted level meets the on-state voltage of the power device.

[0126] Based on the above embodiments, this application also provides a voltage conversion method applied to the control unit in the voltage converter described above. Please refer to... Figure 16 This is a schematic flowchart of the voltage conversion method provided in the embodiments of this application, as shown below. Figure 16 As shown, the method may include:

[0127] S10: Generate 2M+2N+1 control signals according to the preset voltage conversion ratio.

[0128] In this embodiment, the preset voltage conversion ratio can be calculated manually based on the preset input voltage and preset output voltage, or it can be calculated directly by the control unit based on the preset input voltage and preset output voltage. The preset voltage conversion ratio includes: large boost conversion ratio, small boost conversion ratio, large buck conversion ratio, and small buck conversion ratio.

[0129] The control unit can determine the power devices to be turned on and their turn-on sequence based on a preset voltage conversion ratio, and generate 2M+2N+1 control signals. The power devices to be turned on are the same in each control signal, but the turn-on sequence of each power device is different.

[0130] S20: According to the control signal, control each power device in the 2M+2N+1 voltage conversion units to conduct in different phases, so that the voltage conversion circuit outputs an output voltage that meets the preset voltage conversion ratio.

[0131] In this embodiment, the control unit sends control signals to each power device in the 2M+2N+1 voltage conversion units, so that the target power device in each power device is turned on or off according to the turn-on sequence in the control signal, while the remaining power devices are always in an off state, thereby realizing high conversion ratio boost, low conversion ratio boost, high conversion ratio buck, or low conversion ratio buck.

[0132] The specific control signals used to determine the power devices to be turned on and the turn-on sequence can be determined according to the above embodiments, and will not be elaborated here.

[0133] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A voltage conversion circuit, characterized in that, The voltage conversion circuit includes: 2M+2N+1 voltage conversion units, a voltage input terminal, a voltage output terminal, and a reference voltage terminal; wherein M and N are integers greater than or equal to 1. Each voltage conversion unit includes: M first power devices, N-1 second power devices, an energy storage unit, a first input power device, a first output power device, M-1 third power devices, N fourth power devices, a second input power device, a second output power device, and a reference power device; In the 2M+2N+1 voltage conversion units, one end of the first power device is connected, and one end of the second power device in the 2M+2N+1 voltage conversion units is connected. The other ends of the M first power devices and the N-1 second power devices in each voltage conversion unit are both connected to one end of the energy storage unit. One end of the first input power device is connected to the voltage input terminal, one end of the first output power device is connected to the voltage output terminal, and the other ends of the first input power device and the first output power device are both connected to one end of the energy storage unit. One end of the third power device in the 2M+2N+1 voltage conversion units is connected, and one end of the fourth power device in the 2M+2N+1 voltage conversion units is connected. The other ends of the M-1 third power devices and the N fourth power devices in each voltage conversion unit are all connected to the other end of the energy storage unit. One end of the second input power device is connected to the voltage input terminal, one end of the second output power device is connected to the voltage output terminal, and one end of the reference power device is also connected to the reference voltage terminal. The other ends of the second input power device, the second output power device, and the reference power device are all connected to the other end of the energy storage unit.

2. The voltage conversion circuit according to claim 1, characterized in that, If the preset output voltage of the voltage conversion circuit is less than the preset input voltage, and the difference between the preset input voltage and the preset output voltage is greater than the preset voltage difference, all M first power devices are activated, the number of activated N-1 second power devices is greater than or equal to 1, all M-1 third power devices are not activated, and the number of activated N fourth power devices is less than N. The first input power device, the first output power device, the second output power device, and the reference power device are activated.

3. The voltage conversion circuit according to claim 1, characterized in that, If the preset output voltage of the voltage conversion circuit is less than the preset input voltage, and the difference between the preset input voltage and the preset output voltage is less than the preset voltage difference, the number of activated M first power devices is less than M, all N-1 second power devices are not activated, the number of activated M-1 third power devices is greater than or equal to 1, and all N fourth power devices are activated. The first input power device, the first output power device, the second output power device, and the reference power device are activated.

4. The voltage conversion circuit according to claim 1, characterized in that, If the preset output voltage of the voltage conversion circuit is greater than the preset input voltage, and the difference between the preset output voltage and the preset input voltage is greater than the preset voltage difference, all M first power devices are activated, the number of activated N-1 second power devices is greater than or equal to 1, all M-1 third power devices are not activated, and the number of activated N fourth power devices is less than N. The first input power device, the first output power device, the second input power device, and the reference power device are activated.

5. The voltage conversion circuit according to claim 1, characterized in that, If the preset output voltage of the voltage conversion circuit is greater than the preset input voltage, and the difference between the preset output voltage and the preset input voltage is less than the preset voltage difference, the number of activated M first power devices is less than M, all N-1 second power devices are not activated, the number of activated M-1 third power devices is greater than or equal to 1, and all N fourth power devices are activated. The first input power device, the first output power device, the second input power device, and the reference power device are activated.

6. A voltage converter, characterized in that, include: The control unit and the voltage conversion circuit according to any one of claims 1-5; The control unit is connected to the control terminals of each power device in the 2M+2N+1 voltage conversion units of the voltage conversion circuit.

7. The voltage converter as claimed in claim 6, characterized in that, The control unit includes: a conversion ratio matching unit, a control signal generation unit, and a one-hot code generation unit; The input terminal of the conversion ratio matching unit receives a preset input voltage signal and a preset output voltage signal. The output terminal of the conversion ratio matching unit and the one-hot code generation unit are connected to the input terminal of the control signal generation unit. The output terminal of the control signal generation unit is connected to the control terminal of each power device.

8. The voltage converter as claimed in claim 7, characterized in that, The control unit further includes: an error amplification unit and a voltage-controlled oscillator unit; The input terminal of the error amplification unit receives the output sampling voltage and the reference voltage. The output terminal of the error amplification unit is connected to the input terminal of the voltage-controlled oscillator unit, and the output terminal of the voltage-controlled oscillator unit is connected to the one-hot code generation unit.

9. The voltage converter as claimed in claim 7, characterized in that, The control unit further includes a level shifting unit, which is connected between the control signal generation unit and the control terminals of each power device.

10. A voltage conversion method, characterized in that, The method, applied to a control unit in a voltage converter as described in any one of claims 6-9, comprises: 2M+2N+1 control signals are generated based on the preset voltage conversion ratio; According to the control signal, each power device in the 2M+2N+1 voltage conversion units is controlled to conduct in different phases, so that the voltage conversion circuit outputs an output voltage that meets the preset voltage conversion ratio.

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