A multi-phase hybrid DC-DC converter with automatic inductance current sharing
By introducing a switching network and sampling capacitor into a multi-phase hybrid DC-DC converter, automatic current sharing of inductor current and automatic voltage balancing of flying capacitor are achieved. This solves the problems of reduced output range and voltage offset when the number of phases increases in traditional converters, supports arbitrary phase extension, and improves the application applicability and performance of the converter.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- UNIV OF MACAU
- Filing Date
- 2026-02-13
- Publication Date
- 2026-06-05
AI Technical Summary
Traditional multi-inductor hybrid buck converters have a reduced output range when the number of phases is increased, making them difficult to adapt to a wide range of applications. Furthermore, they cannot simultaneously achieve cross-capacitor voltage balancing and automatic inductor current sharing under multi-phase cross-connection, resulting in performance compromises.
Design a multi-phase hybrid DC-DC converter with automatic inductor current sharing. By introducing a switching network, flying capacitor, energy storage inductor, and sampling capacitor into the phase unit, automatic inductor current sharing and automatic flying capacitor voltage balancing are achieved through timing adjustment. The controller controls the on and off of the NMOS transistor, supporting arbitrary phase expansion.
It achieves inductor current sharing and flying capacitor voltage balancing under any number of phases, expands the application range of the converter, simplifies the circuit structure, and improves design flexibility and applicability.
Smart Images
Figure CN122159672A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of buck converter technology, and more specifically to a multi-phase hybrid DC-DC converter with automatic inductor current sharing. Background Technology
[0002] In traditional multi-inductor hybrid buck converters, the output range decreases as the number of phases increases, directly limiting the converter's operating range and making it difficult to adapt to a wider range of applications. Furthermore, when there is an error in the duty cycle, the flying capacitor voltage will deviate. To correct this deviation, additional circuitry must be introduced for calibration, thus increasing the overall circuit complexity.
[0003] However, when using a multi-phase cross-connect buck converter to achieve multi-phase operation, the number of phases can be flexibly expanded to any number. But under this configuration, only one of the flying capacitor voltage balancing and inductor current automatic current sharing can be achieved, and these two key requirements cannot be met at the same time, resulting in a performance compromise.
[0004] In contrast, multi-phase interleaved buck converters can simultaneously achieve cross capacitor voltage balancing and inductor current sharing, but this structure cannot be extended to more phases, thus limiting design flexibility and affecting its applicability in complex systems. Summary of the Invention
[0005] In view of this, embodiments of the present invention provide a multi-phase hybrid DC-DC converter with automatic inductor current sharing.
[0006] The first aspect of this invention provides a multi-phase hybrid DC-DC converter with automatic inductor current sharing, comprising multiple phase units. Each phase unit includes a switching network, a flying capacitor, an energy storage inductor, and a sampling capacitor. The switching network consists of NMOS transistors connected in series. The flying capacitor is connected between the output terminal of the first NMOS transistor and the input terminal of the last NMOS transistor in the switching network. A sampling capacitor is connected between the center tap of the switching network in each phase unit and the center tap of the switching network in the next phase unit. One end of the energy storage inductor is connected to the switching network, and the other end is connected to the common output terminal of the converter. By adjusting the timing of the switching networks in the phase units, the multi-phase hybrid DC-DC converter outputs a DC voltage signal at the common output terminal while simultaneously achieving automatic inductor current sharing and automatic flying capacitor voltage balancing within the phase units.
[0007] Furthermore, the switching network specifically includes a first NMOS transistor, a second NMOS transistor, a third NMOS transistor, and a fourth NMOS transistor connected in series, with the source of the previous NMOS transistor connected to the drain of the next NMOS transistor; wherein the first NMOS transistor serves as the first NMOS transistor in the switching network, and its drain is connected to the high-voltage power bus as a DC voltage signal input; the fourth NMOS transistor serves as the last NMOS transistor in the switching network, and its source is connected to power ground.
[0008] Furthermore, each of the phase units has a first operating state, a second operating state, and a third operating state; In the first operating state, the first NMOS transistor, the second NMOS transistor, and the third NMOS transistor are turned off, and the fourth NMOS transistor is turned on; the energy storage inductor is connected to power ground; In the second operating state, the first NMOS transistor and the third NMOS transistor are turned on, and the second NMOS transistor and the fourth NMOS transistor are turned off; the flying capacitor is connected to the high-voltage power supply bus and the energy storage inductor; the energy storage inductor is also connected to the sampling capacitor; In the third operating state, the second and fourth NMOS transistors are turned on, while the first and third NMOS transistors are turned off; the flying capacitor is connected between the sampling capacitor and the energy storage inductor.
[0009] Furthermore, the plurality of phase units specifically includes a first phase unit, a second phase unit, a third phase unit, and a fourth phase unit; within one switching cycle, the operating states of the first phase unit, the second phase unit, the third phase unit, and the fourth phase unit change in the following order: During the first time interval, the first phase unit operates in the second operating state, the second and third phase units operate in the first operating state, and the fourth phase unit operates in the third operating state. Between the first time interval and the second time interval, all phase units operate in the first working state; During the second time interval, the first phase unit operates in the third operating state, the second phase unit operates in the second operating state, and the third and fourth phase units operate in the first operating state. Between the second and third time intervals, all phase units operate in the first working state; During the third time interval, the second phase unit operates in the third operating state, and the third phase unit operates in the second operating state; the first phase unit and the fourth phase unit operate in the first operating state. Between the third and fourth time intervals, all phase units operate in the first working state; During the fourth time interval, the third phase unit operates in the third operating state, the fourth phase unit operates in the second operating state, and the first phase unit and the second phase unit operate in the first operating state. Between the fourth time interval and the first time interval of the next switching cycle, all phase units operate in the first operating state.
[0010] Further, during the first time interval; the energy storage inductor of the first phase unit receives the charge input from the flying capacitor of the first phase unit and the flying capacitor of the fourth phase unit; wherein the charge input of the flying capacitor of the first phase unit is obtained by charging it through a high-voltage power bus; the charge input of the flying capacitor of the fourth phase unit is obtained by discharging it through a power ground; the sampling capacitors between the first phase unit and the second phase unit, between the second phase unit and the third phase unit, and between the third phase unit and the fourth phase unit sample the charge of the flying capacitor of the fourth phase unit; During the second time interval; the energy storage inductor of the second phase unit receives the charge input from the flying capacitor of the second phase unit and the flying capacitor of the first phase unit; wherein the charge input of the flying capacitor of the second phase unit is obtained by charging it through a high-voltage power bus; the charge input of the flying capacitor of the first phase unit is obtained by discharging it through a power ground; the sampling capacitor between the first phase unit and the second phase unit samples the charge of the flying capacitor of the first phase unit; During the third time interval; the energy storage inductor of the third phase unit receives the charge input from the flying capacitor of the third phase unit and the flying capacitor of the second phase unit; wherein the charge input of the flying capacitor of the third phase unit is obtained by charging it through a high-voltage power bus; the charge input of the flying capacitor of the second phase unit is obtained by discharging it through a power ground; the sampling capacitor between the second phase unit and the third phase unit samples the charge of the flying capacitor of the second phase unit; During the fourth time interval, the energy storage inductor of the fourth phase unit receives the charge input from the flying capacitor of the fourth phase unit and the flying capacitor of the third phase unit; wherein the charge input of the flying capacitor of the fourth phase unit is obtained by charging it through a high-voltage power bus; the charge input of the flying capacitor of the third phase unit is obtained by discharging it through a power ground; and the sampling capacitor between the third phase unit and the fourth phase unit samples the charge of the flying capacitor of the third phase unit.
[0011] Furthermore, the switching of the operating state of the switching network is controlled by a controller connected to the gate of the NMOS transistor; the controller takes the common output terminal of the multi-phase hybrid DC-DC converter as the feedback signal input, and the generated drive signal output is output to the gate of each NMOS transistor in the switching network through a gate driver containing a bootstrap circuit and a level shifter, so as to control the NMOS transistor to be turned on or off.
[0012] Further, the controller specifically includes a current sensing network, a type-II compensation network, an error amplifier, a synchronous hysteresis controller, a duty cycle replicator, and a non-overlapping module. The current sensing network detects the feedback signal at the common output of the multi-phase hybrid DC-DC converter and generates a detection signal output to the synchronous hysteresis controller. The type-II compensation network and the error amplifier modulate the feedback signal, generating a modulation signal output to the synchronous hysteresis controller. The synchronous hysteresis controller connects to both the modulation signal input and the feedback signal input, compares the signal with the detection signal, and outputs a PWM signal to the duty cycle replicator. The duty cycle replicator generates a multi-phase PWM signal with phase intervals based on the PWM signal and outputs it to the non-overlapping module. The non-overlapping module converts the multi-phase PWM signal output by the duty cycle replicator into a drive signal with a dead time interval and outputs it to the switching network of the multi-phase hybrid DC-DC converter to control the NMOS transistor to turn on or off.
[0013] Furthermore, the current detection network specifically includes a detection resistor, a detection capacitor, and a power amplifier; one end of the detection resistor is connected between the energy storage inductor and the switching network in each phase unit; the positive and negative input terminals of the power amplifier are respectively connected to the other end of the detection resistor and the common output terminal of the multi-phase hybrid DC-DC converter to detect the inductor current of the energy storage inductor and generate a detection signal output at the output terminal; The detection capacitor is connected between the positive and negative input terminals of the power amplifier and is used to suppress common-mode noise of the detection resistor.
[0014] Furthermore, the duty cycle replicator also receives a time-division signal input and replicates the PWM signal according to the time-division signal input to generate a multi-phase PWM signal.
[0015] Furthermore, the phase in the drive signal corresponds to different operating states of the multi-phase hybrid DC-DC converter, and the dead interval corresponds to the interval between different operating states of the multi-phase hybrid DC-DC converter.
[0016] The embodiments of the present invention have the following beneficial effects: The multi-phase hybrid DC-DC converter with automatic inductor current sharing of the present invention inserts sampling capacitors between adjacent phases. Through the charging and discharging of the sampling capacitors, charge transfer occurs in each operating mode of the DC-DC converter, ensuring that the total charge received by each energy storage inductor within a complete switching cycle is equal to twice the charge of the sampling capacitors, thereby achieving automatic current sharing of the energy storage inductors. The DC-DC converter of the embodiments of the present invention also features a modular design for the phase units, enabling the DC-DC converter to support arbitrary phase expansion. Therefore, it simultaneously achieves the goal of being expandable to any number of phases and automatically balancing inductor current and flying capacitor voltage, and has broad application prospects.
[0017] Additional aspects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description or may be learned by practice of the invention. Attached Figure Description
[0018] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0019] Figure 1 This is a schematic diagram of the basic structure of a multi-phase hybrid DC-DC converter with automatic inductor current sharing according to the present invention. Figure 2 This is a schematic diagram of the working mode of the switching array in an embodiment of a multi-phase hybrid DC-DC converter with automatic inductor current sharing according to the present invention. Figure 3 This is a schematic diagram of the working phase of the switching array in an embodiment of a multi-phase hybrid DC-DC converter with automatic inductor current sharing according to the present invention; Figure 4 This is a schematic diagram of the controller structure in an embodiment of a multi-phase hybrid DC-DC converter with automatic inductor current sharing according to the present invention; Figure 5 This is a schematic diagram of the steady-state test results of a multi-phase hybrid DC-DC converter with automatic inductor current sharing according to the present invention. Figure 6 This is a schematic diagram of the transient test results of a multi-phase hybrid DC-DC converter with automatic inductor current sharing according to the present invention. Detailed Implementation
[0020] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.
[0021] like Figure 1 As shown, this embodiment of the invention provides a multi-phase hybrid DC-DC converter with automatic inductor current sharing, including multiple phase units. Each phase unit includes a switching network, a flying capacitor, an energy storage inductor, and a sampling capacitor. The switching network consists of NMOS transistors connected in series. The flying capacitor is connected between the output terminal of the first NMOS transistor and the input terminal of the last NMOS transistor in the switching network. A sampling capacitor is connected between the center tap of the switching network in each phase unit and the center tap of the switching network in the next phase unit. One end of the energy storage inductor is connected to the switching network, and the other end is connected to the common output terminal of the converter. By adjusting the timing of the switching network in the phase unit, the multi-phase hybrid DC-DC converter outputs a DC voltage signal at the common output terminal while simultaneously achieving automatic inductor current sharing and automatic flying capacitor voltage balancing within the phase unit.
[0022] This invention embodiment inserts a sampling capacitor C between adjacent phases. S This achieves automatic balancing of capacitor voltage and inductor current, and can be extended to any number of phases.
[0023] Preferably, in this embodiment of the invention, the switching network specifically includes a first NMOS transistor, a second NMOS transistor, a third NMOS transistor, and a fourth NMOS transistor connected in series, with the source of the first NMOS transistor connected to the drain of the next NMOS transistor; wherein the first NMOS transistor serves as the first NMOS transistor in the switching network, and its drain is connected to the high-voltage power supply bus as a DC voltage signal input; the fourth NMOS transistor serves as the last NMOS transistor in the switching network, and its source is connected to power ground.
[0024] like Figure 2 As shown, each phase unit has a first operating state, a second operating state, and a third operating state; In the first operating state, the first, second, and third NMOS transistors are turned off, and the fourth NMOS transistor is turned on; the energy storage inductor is connected to power ground; In the second operating state, the first and third NMOS transistors are turned on, while the second and fourth NMOS transistors are turned off; the flying capacitor connects the high-voltage power supply bus and the energy storage inductor; the energy storage inductor is also connected to the sampling capacitor; In the third operating state, the second and fourth NMOS transistors are turned on, while the first and third NMOS transistors are turned off; the flying capacitor is connected between the sampling capacitor and the energy storage inductor.
[0025] The multiple phase units specifically include a first phase unit, a second phase unit, a third phase unit, and a fourth phase unit; within one switching cycle, the operating states of the first phase unit, the second phase unit, the third phase unit, and the fourth phase unit change in the following order: During the first time interval, the first phase unit operates in the second operating state, the second and third phase units operate in the first operating state, and the fourth phase unit operates in the third operating state. Between the first time interval and the second time interval, all phase units operate in the first working state; During the second time interval, the first phase unit operates in the third operating state, the second phase unit operates in the second operating state, and the third and fourth phase units operate in the first operating state. Between the second and third time intervals, all phase units operate in the first working state; During the third time interval, the second phase unit operates in the third operating state, the third phase unit operates in the second operating state, and the first phase unit and the fourth phase unit operate in the first operating state. Between the third and fourth time intervals, all phase units operate in the first working state; During the fourth time interval, the third phase unit operates in the third operating state, the fourth phase unit operates in the second operating state, and the first phase unit and the second phase unit operate in the first operating state. Between the fourth time interval and the first time interval of the next switching cycle, all phase units operate in the first operating state.
[0026] Specifically, such as Figure 3 The diagram shows the operating sequence of the structure proposed in this invention when the duty cycle D < 0.25. When the converter operates in the first time interval T... ON1 At this time, the four phase units are in working states S1, S0, S0, and S2 respectively, and the three sampling capacitors C S1 C S2 C S3 Sample charge Q4=Q S The energy storage inductor L1 receives a charge of Q1 + Q4, where charge Q1 is used to supply the flying capacitor C. F1 Charging, charge Q4 is used to charge the flying capacitor C. F4 Discharge. During the second time interval T ON2 In the middle, the sampling capacitor C S1 Release and flying capacitor C F1 In series, the charge received by the energy storage inductor L2 is Q1 + Q2, where Q1 = Q S Q1 provides the flying capacitor CF1 Discharge, Q2 supplies power to the flying capacitor C F2 Charging. During the fourth time interval T... ON3 In the above, the charge received by the energy storage inductor L3 is Q2 + Q3, where Q2 = Q S Q2 supplies capacitor C F2 Discharge, Q3 supplies power to capacitor C F3 Charging. During the fourth time interval T... ON4 In the above, the charge received by the energy storage inductor L4 is Q3 + Q4, where Q3 = Q S Q3 provides the flying capacitor C F3 Discharge, Q4 supplies power to the flying capacitor C F4 Charging. It can be seen that, in one switching cycle of this embodiment of the invention, all energy storage inductors receive a charge of 2Q. S This achieves the effect of automatic current sharing in the inductor.
[0027] In some embodiments, such as Figure 4 As shown, the switching of the operating state of the switching network is controlled by a controller connected to the gate of the NMOS transistor. The controller takes the common output terminal of the multi-phase hybrid DC-DC converter as the feedback signal input, and the generated drive signal output is output to the gate of each NMOS transistor in the switching network through a gate driver (BST) containing a bootstrap circuit and a level shifter (LS) to control the NMOS transistor to turn on or off.
[0028] Preferably, the controller specifically includes a current sensing network, a Type-II compensation network, an error amplifier (EA), a synchronous hysteresis controller (TR), a duty cycle replicator (D-copy), and a non-overlap module. The current sensing network detects the feedback signal at the common output of the multi-phase hybrid DC-DC converter and generates a detection signal output to the synchronous hysteresis controller. The Type-II compensation network and the error amplifier modulate the feedback signal, generating a modulated signal output to the synchronous hysteresis controller. The synchronous hysteresis controller connects to both the modulated signal input and the feedback signal input, compares the signal with the detection signal, and outputs a PWM signal to the duty cycle replicator. The duty cycle replicator generates a multi-phase PWM signal with phase intervals based on the PWM signal and outputs it to the non-overlap module. The non-overlap module converts the multi-phase PWM signal output by the duty cycle replicator into a drive signal with a dead time interval, outputting it to the switching network of the multi-phase hybrid DC-DC converter to control the NMOS transistor to turn on or off.
[0029] Specifically, the current sensing network includes a sensing resistor R1, a sensing capacitor C1, and a power amplifier AMP. One end of the sensing resistor is connected between the energy storage inductor L and the switching network in each phase unit. The positive and negative input terminals of the power amplifier are connected to the other end of the sensing resistor and the common output terminal of the multi-phase hybrid DC-DC converter, respectively, to detect the inductor current of the energy storage inductor and generate a detection signal output at the output terminal. The sensing capacitor is connected between the positive and negative input terminals of the power amplifier to suppress common-mode noise from the sensing resistor.
[0030] Preferably, the duty cycle replicator also receives a time-division signal input and replicates the PWM signal according to the time-division signal input to generate a multi-phase PWM signal. The phase in the drive signal corresponds to the different operating states of the multi-phase hybrid DC-DC converter, and the dead interval corresponds to the interval between the different operating states of the multi-phase hybrid DC-DC converter.
[0031] The steady-state detection results of the multi-phase hybrid DC-DC converter in this embodiment of the invention are as follows: Figure 5 As shown. Figure 5 The switching node waveforms and inductor current waveforms of the proposed buck converter are shown when the output voltages are 1V and 1.8V, respectively. The proposed structure achieves automatic balancing of the flying capacitor in both cases where D < 0.25 and D > 0.25, with the maximum error of the inductor current not exceeding 1.8%.
[0032] The transient detection results of the multi-phase hybrid DC-DC converter in this embodiment of the invention are as follows: Figure 6 As shown. Figure 6 The figure shows the test waveform when the load changes from light to heavy load, with the converter operating at a 12V input voltage and a 1V output voltage. The load changes by 6A within 20ns. This converter can magnetize all inductors simultaneously, maximizing the inductor current slope, and its voltage undershoot is only 65mV.
[0033] It should be noted that the specific number of phase units in the multi-phase hybrid DC-DC converter in the above embodiments is only used as an example. The phase units and sampling capacitors of the present invention are modularly connected, so the same design can be used to expand to any phase, thereby simultaneously achieving automatic current sharing of inductor current, automatic voltage balancing of flying capacitors, and arbitrary phase expansion.
[0034] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.
[0035] Furthermore, the terms "first," "second," etc., used in the embodiments of this invention are for descriptive purposes only and should not be construed as indicating or implying relative importance, or implicitly specifying the number of technical features indicated in this embodiment. Therefore, features defined with terms such as "first" and "second" in the embodiments of this invention can explicitly or implicitly indicate that the embodiment includes at least one of those features. In the description of this invention, the word "multiple" means at least two or more, such as two, three, four, etc., unless otherwise explicitly specified in the embodiments.
[0036] In embodiments of the present invention, the terms "comprising," "including," or any other variations thereof are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element. Furthermore, components, features, and elements with the same names in different embodiments of the present invention may have the same meaning or different meanings, the specific meaning of which must be determined by its interpretation in that specific embodiment or further in conjunction with the context of that specific embodiment.
[0037] Although embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention. Other embodiments of the present invention will readily conceive of by considering the specification and practicing the invention. This application is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein. The specification and embodiments are to be considered exemplary only, and the true scope and spirit of the invention are indicated by the following claims.
Claims
1. A multi-phase hybrid DC-DC converter with automatic inductor current sharing, characterized in that, The converter comprises multiple phase units, each including a switching network, a flying capacitor, an energy storage inductor, and a sampling capacitor. The switching network consists of NMOS transistors connected in series. The flying capacitor is connected between the output of the first NMOS transistor and the input of the last NMOS transistor in the switching network. A sampling capacitor is connected between the center tap of the switching network in each phase unit and the center tap of the switching network in the next phase unit. One end of the energy storage inductor is connected to the switching network, and the other end is connected to the common output terminal of the converter. The multi-phase hybrid DC-DC converter, by adjusting the timing of the switching networks in the phase units, outputs a DC voltage signal at the common output terminal while simultaneously achieving automatic current sharing of the inductor and automatic voltage balancing of the flying capacitor within the phase units.
2. The multi-phase hybrid DC-DC converter with automatic inductor current sharing according to claim 1, characterized in that, The switching network specifically includes a first NMOS transistor, a second NMOS transistor, a third NMOS transistor, and a fourth NMOS transistor connected in series, with the source of the previous NMOS transistor connected to the drain of the next NMOS transistor; wherein the first NMOS transistor is the first NMOS transistor in the switching network, and its drain is connected to the high-voltage power bus as a DC voltage signal input; the fourth NMOS transistor is the last NMOS transistor in the switching network, and its source is connected to power ground.
3. A multi-phase hybrid DC-DC converter with automatic inductor current sharing according to claim 2, characterized in that, Each of the phase units has a first operating state, a second operating state, and a third operating state; In the first operating state, the first NMOS transistor, the second NMOS transistor, and the third NMOS transistor are turned off, and the fourth NMOS transistor is turned on; the energy storage inductor is connected to power ground; In the second operating state, the first NMOS transistor and the third NMOS transistor are turned on, and the second NMOS transistor and the fourth NMOS transistor are turned off; the flying capacitor is connected to the high-voltage power supply bus and the energy storage inductor; the energy storage inductor is also connected to the sampling capacitor; In the third operating state, the second and fourth NMOS transistors are turned on, while the first and third NMOS transistors are turned off; the flying capacitor is connected between the sampling capacitor and the energy storage inductor.
4. A multi-phase hybrid DC-DC converter with automatic inductor current sharing according to claim 3, characterized in that, The plurality of phase units specifically includes a first phase unit, a second phase unit, a third phase unit, and a fourth phase unit; within one switching cycle, the operating states of the first phase unit, the second phase unit, the third phase unit, and the fourth phase unit change in the following order: During the first time interval, the first phase unit operates in the second operating state, the second and third phase units operate in the first operating state, and the fourth phase unit operates in the third operating state. Between the first time interval and the second time interval, all phase units operate in the first working state; During the second time interval, the first phase unit operates in the third operating state, the second phase unit operates in the second operating state, and the third and fourth phase units operate in the first operating state. Between the second and third time intervals, all phase units operate in the first working state; During the third time interval, the second phase unit operates in the third operating state, and the third phase unit operates in the second operating state; the first phase unit and the fourth phase unit operate in the first operating state. Between the third and fourth time intervals, all phase units operate in the first working state; During the fourth time interval, the third phase unit operates in the third operating state, the fourth phase unit operates in the second operating state, and the first phase unit and the second phase unit operate in the first operating state. Between the fourth time interval and the first time interval of the next switching cycle, all phase units operate in the first operating state.
5. A multi-phase hybrid DC-DC converter with automatic inductor current sharing according to claim 4, characterized in that, During the first time interval; the energy storage inductor of the first phase unit receives the charge input from the flying capacitor of the first phase unit and the flying capacitor of the fourth phase unit; wherein the charge input of the flying capacitor of the first phase unit is obtained by charging it through a high-voltage power bus; the charge input of the flying capacitor of the fourth phase unit is obtained by discharging it through a power ground; the sampling capacitors between the first phase unit and the second phase unit, between the second phase unit and the third phase unit, and between the third phase unit and the fourth phase unit sample the charge of the flying capacitor of the fourth phase unit; During the second time interval, the energy storage inductor of the second phase unit receives the charge input from the flying capacitor of the second phase unit and the flying capacitor of the first phase unit. The charge input of the flying capacitor of the second phase unit is obtained by charging it through the high-voltage power bus; the charge input of the flying capacitor of the first phase unit is obtained by discharging it through the power ground; the sampling capacitor between the first phase unit and the second phase unit samples the charge of the flying capacitor of the first phase unit. During the third time interval, the energy storage inductor of the third phase unit receives the charge input from the flying capacitor of the third phase unit and the flying capacitor of the second phase unit. The charge input of the flying capacitor of the third phase unit is obtained by charging it through the high-voltage power supply bus; the charge input of the flying capacitor of the second phase unit is obtained by discharging it through the power ground; the sampling capacitor between the second phase unit and the third phase unit samples the charge of the flying capacitor of the second phase unit. During the fourth time interval, the energy storage inductor of the fourth phase unit receives the charge input from the flying capacitor of the fourth phase unit and the flying capacitor of the third phase unit. The charge input of the flying capacitor of the fourth phase unit is obtained by charging it through a high-voltage power supply bus; the charge input of the flying capacitor of the third phase unit is obtained by discharging it through a power ground; the sampling capacitor between the third phase unit and the fourth phase unit samples the charge of the flying capacitor of the third phase unit.
6. A multi-phase hybrid DC-DC converter with automatic inductor current sharing according to claim 1, characterized in that, The switching of the operating state of the switching network is controlled by a controller connected to the gate of the NMOS transistor. The controller takes the common output terminal of the multi-phase hybrid DC-DC converter as the feedback signal input, and the generated drive signal output is output to the gate of each NMOS transistor in the switching network through a gate driver containing a bootstrap circuit and a level shifter, so as to control the NMOS transistor to turn on or off.
7. A multi-phase hybrid DC-DC converter with automatic inductor current sharing according to claim 6, characterized in that, The controller specifically includes a current sensing network, a type-II compensation network, an error amplifier, a synchronous hysteresis controller, a duty cycle replicator, and a non-overlapping module. The current sensing network detects the feedback signal at the common output of the multi-phase hybrid DC-DC converter and generates a detection signal, which is output to the synchronous hysteresis controller. The type-II compensation network and the error amplifier modulate the feedback signal, generating a modulated signal, which is output to the synchronous hysteresis controller. The synchronous hysteresis controller is connected to both the modulated signal input and the feedback signal input, and after comparing it with the detection signal, outputs a PWM signal to the duty cycle replicator. The duty cycle replicator generates a multi-phase PWM signal with phase intervals based on the PWM signal and outputs it to the non-overlapping module. The non-overlapping module converts the multi-phase PWM signal output by the duty cycle replicator into a drive signal with a dead time interval, which is output to the switching network of the multi-phase hybrid DC-DC converter to control the NMOS transistor to turn on or off.
8. A multi-phase hybrid DC-DC converter with automatic inductor current sharing according to claim 7, characterized in that, The current detection network specifically includes a detection resistor, a detection capacitor, and a power amplifier; one end of the detection resistor is connected between the energy storage inductor and the switching network in each phase unit; the positive and negative input terminals of the power amplifier are respectively connected to the other end of the detection resistor and the common output terminal of the multi-phase hybrid DC-DC converter to detect the inductor current of the energy storage inductor and generate a detection signal output at the output terminal. The detection capacitor is connected between the positive and negative input terminals of the power amplifier and is used to suppress common-mode noise of the detection resistor.
9. A multi-phase hybrid DC-DC converter with automatic inductor current sharing according to claim 7, characterized in that, The duty cycle replicator also receives a time-division signal input and replicates the PWM signal according to the time-division signal input to generate a multi-phase PWM signal.
10. A multi-phase hybrid DC-DC converter with automatic inductor current sharing according to claim 7, characterized in that, The phase in the drive signal corresponds to different operating states of the multi-phase hybrid DC-DC converter, and the dead interval corresponds to the interval between different operating states of the multi-phase hybrid DC-DC converter.