Multi-phase DCDC converter and switching power supply

Abstract

The invention provides a multi-phase DCDC converter and a switching power supply, and relates to the technical field of switching power supplies. The multi-phase DCDC converter comprises n switched capacitor networks, n inductors and a controller, each switched capacitor network comprises n output ends arranged in sequence, and the number of phases of the multi-phase DCDC converter is n; the input ends of the n switched capacitor networks receive input voltage, one end of each inductor is connected with the output ends of the n switched capacitor networks at different positions, and the other ends of the n inductors are connected to serve as the output end of the multi-phase DCDC converter. The first input end and the second input end of the controller are respectively connected with any output end of the n switched capacitor networks and the output end of the multi-phase DCDC converter, and the output end of the controller is connected with the control ends of the n switched capacitor networks. According to the invention, automatic current sharing of the inductor can be realized, and the reliability of the DCDC converter is improved.

Description

Technical Field

[0001] The present application relates to the technical field of switching power supplies, and in particular to a multi-phase DCDC converter and a switching power supply. Background Art

[0002] As a DC / DC circuit topology, the buck converter is widely used in various power supply fields because of its advantages such as low voltage / current stress of switching devices, wide input and output range, few passive components, high efficiency, reliability and flexibility.

[0003] Buck converters with high transformation ratio are widely used in data centers and automotive electronics. Multi-phase hybrid buck converters can provide greater output power, but existing multi-phase hybrid buck converters cannot achieve automatic current sharing of the inductor current, resulting in reduced reliability of the DCDC converter. Summary of the invention

[0004] The purpose of the present application is to provide a multi-phase DCDC converter and a switching power supply to address the deficiencies in the above-mentioned prior art, so as to achieve automatic current sharing of the inductors and improve the reliability of the DCDC converter.

[0005] To achieve the above purpose, the technical solution adopted in the embodiment of the present application is as follows:

[0006] In a first aspect, an embodiment of the present application provides a multi-phase DCDC converter, the multi-phase DCDC converter comprising: n switched capacitor networks, n inductors and a controller, wherein each switched capacitor network comprises n output terminals arranged in sequence, and the number of phases of the multi-phase DCDC converter is n;

[0007] The input ends of the n switched capacitor networks receive input voltages, one end of each inductor is respectively connected to output ends at different positions of the n switched capacitor networks, the other ends of the n inductors are connected as the output end of the multi-phase DCDC converter, the first input end and the second input end of the controller are respectively connected to any output end of the n switched capacitor networks and the output end of the multi-phase DCDC converter, and the output end of the controller is connected to the control end of the n switched capacitor networks.

[0008] In a possible implementation, each of the switch capacitor networks includes: n first power tubes, n-1 second power tubes and n-1 flying capacitors;

[0009] Among them, n first power tubes are connected in series, n-1 series nodes are respectively connected to one end of the n-1 flying capacitors, the other ends of the n-1 flying capacitors are respectively grounded through n-1 second power tubes, and the other ends of the n-1 flying capacitors and the other end of the last first power tube serve as n output ends of each switch capacitor network.

[0010] In a possible implementation, the controller includes: a control signal generating circuit and n drive control circuits;

[0011] The first input terminal and the second input terminal of the control signal generating circuit serve as the first input terminal and the second input terminal of the controller respectively, and the n output terminals of the control signal generating circuit are respectively connected to the control terminals of the n driving control circuits.

[0012] In a possible implementation, the control signal generating circuit includes: a current detection module, a hysteresis controller, n-1 duty cycle replicators and n switch signal generating modules;

[0013] The first input end and the second input end of the current detection module serve as the first input end and the second input end of the control signal generating circuit respectively; the output end of the current detection module is connected to the first input end of the hysteresis controller; the second input end of the hysteresis controller is connected to the second input end of the current detection module; the first output end of the hysteresis controller is connected to the input end of a switch signal generating module and the first input end of n-1 duty cycle replicators; the second output end of the hysteresis controller is connected to the second input end of the n-1 duty cycle replicators; and the output end of the n-1 duty cycle replicators is connected to the input end of the n-1 switch signal generating module;

[0014] The output ends of the n switch signal generating modules serve as the output ends of the control signal generating circuit.

[0015] In a possible implementation, the hysteresis controller includes: a differential amplifier, a comparator, an error amplifier, a first capacitor, a first switch, a compensation network and a hysteresis comparator;

[0016] The positive input terminal of the differential amplifier is used as the first input terminal of the hysteresis controller, the negative input terminal of the differential amplifier and the positive input terminal of the comparator are connected as the second input terminal of the hysteresis controller, the output terminal of the differential amplifier is connected to the positive input terminal of the hysteresis comparator through the first capacitor, and the first switch is connected in parallel to both sides of the first capacitor;

[0017] The input end of the compensation network is connected to the positive input end of the comparator, the first output end of the compensation network is connected to the negative input end of the error amplifier, and the second output end of the compensation network is connected to the output end of the error amplifier and the negative input end of the hysteresis comparator;

[0018] The output end of the hysteresis comparator serves as the first output end of the hysteresis controller, the output end of the comparator serves as the second output end of the hysteresis controller, and the negative input end of the comparator and the positive input end of the error amplifier are connected to a preset reference voltage.

[0019] In a possible implementation, the compensation network includes: a first resistor, a second resistor, a second capacitor, and a third capacitor;

[0020] The first resistor and the second capacitor are connected in parallel, one end of the parallel connection serves as the input end of the compensation network, the other end of the parallel connection serves as the first output end of the compensation network, and the other end of the parallel connection is also connected to the second resistor and one end of the third capacitor in sequence, and the other end of the third capacitor serves as the second output end of the compensation network.

[0021] In a possible implementation, the control signal generating circuit further includes: n selectors;

[0022] The 0 input ends of the n selectors are connected to the flying capacitor power-on controller, the 1 input ends of the n selectors are respectively connected to the output ends of the n switch signal generating modules, and the output ends of the n selectors serve as the output ends of the control signal generating circuit.

[0023] In a possible implementation, each driving control circuit includes: n first gate drivers, n-1 second gate drivers, and n level shifters;

[0024] Each output end of the control signal generating circuit is connected to the input ends of n level shifters and the input ends of n-1 second gate drivers in the corresponding drive control circuit, the output ends of the n level shifters are connected to the input ends of n first gate drivers, and the output ends of the n first gate drivers and the output ends of the n-1 second gate drivers are connected to the control end of a switch capacitor network.

[0025] In a possible implementation manner, the first first power tube and the n-1 second power tubes among the n first power tubes are CMOS tubes, and the remaining first power tubes are LDMOS tubes.

[0026] In a second aspect, an embodiment of the present application further provides a switching power supply, wherein the switching power supply comprises a multi-phase DCDC converter as described in any one of the first aspects.

[0027] The beneficial effects of this application are:

[0028] The multi-phase DCDC converter and switching power supply provided by the present application are characterized in that one end of each inductor is respectively connected to the output ends of n switching capacitor networks at different positions, so that the output ends of the n switching capacitor networks are connected to the n inductors in an interlaced manner, and during each inductor charging period, an equal amount of charge is obtained through the n switching capacitor networks, thereby achieving automatic current sharing of the inductor current and improving the reliability of the multi-phase DCDC converter. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0030] Figure 1 is a schematic diagram of an existing multi-phase DCDC converter;

[0031] Figure 2 is a schematic diagram of another existing multi-phase DCDC converter;

[0032] Figure 3 The principle framework of the multi-phase DCDC converter provided in the embodiment of the present application Figure 1 ;

[0033] Figure 4 A schematic diagram of the structure of a switched capacitor network provided in an embodiment of the present application;

[0034] Figure 5 The principle framework of the multi-phase DCDC converter provided in the embodiment of the present application Figure 2 ;

[0035] Figure 6 The original circuit frame of the multi-phase DCDC converter provided in the embodiment of the present application Figure 3 ;

[0036] Figure 7 A circuit diagram of a multi-phase DCDC converter provided in an embodiment of the present application;

[0037] Figure 8 A working waveform diagram of the hysteresis controller provided in an embodiment of the present application;

[0038] Fig. 9 A working principle diagram provided for an embodiment of the present application;

[0039] Fig.10 A schematic diagram of steady-state operating test results provided in an embodiment of the present application. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments.

[0041] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0042] In addition, the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequential order. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0043] It should be noted that, in the absence of conflict, the features in the embodiments of the present application may be combined with each other.

[0044] Figure 1 Schematic diagram of an existing multi-phase DCDC converter, such as Figure 1 As shown, the multi-phase DCDC converter has two sets of switched capacitors SC A and SC B , two inductors L1 and L2, when the inductor L1 is charged (TON1), its total charge ∑Q ON1 =2Q1+Q2, Q1 and Q2 are SC A and SC B The output charge, when the inductor L2 is charged (TON2), the total charge ∑Q ON2 =Q1+2Q2. It can be seen that the inductances of the two inductors are not equal in one cycle, resulting in uneven current flow in the inductors, requiring additional current detection and feedback loops for calibration.

[0045] Figure 2Schematic diagram of another existing multi-phase DCDC converter, such as Figure 1 As shown, the multi-phase DCDC converter includes a set of switched capacitors SC and three inductors L1, L2 and L3. When the inductor L1 is charged (TON1), the total charge ∑Q ON1 When the inductor L2 is charged (TON2), the total charge ∑Q ON2 When the inductor L3 is charged (TON3), the total charge ∑Q ON3 is Q. It can be seen that the inductances of the three inductors are not equal in one cycle, the current ratio of the three inductors is 2:2:1, the inductor currents are not evenly distributed, and additional current detection and feedback loops are required for calibration.

[0046] Based on the above analysis, the present application intends to provide a multi-phase DCDC converter to achieve automatic inductor current sharing.

[0047] Figure 3 The principle framework of the multi-phase DCDC converter provided in the embodiment of the present application Figure 1 ,like Figure 3 As shown, the multi-phase DCDC converter may include: n switched capacitor networks SC1 to SC n , n inductors L1~L n and a controller 10, wherein each switched capacitor network SC i It includes n output terminals OUT1 to OUT2 arranged in sequence. n , the number of phases of the multi-phase DCDC converter is n.

[0048] n switched capacitor networks SC1~SC n Input terminals IN1 to IN n Receiving the input voltage VCC, each inductor L i One end of each switch capacitor network SC1 to SC n Different positions of the output terminal OUT i , n inductors L1~L n The other end is connected as the output end of the multi-phase DCDC converter, and the first input end and the second input end of the controller 10 are respectively connected to n switch capacitor networks SC1 to SC n Any output end of the controller 10 and the output end of the multi-phase DCDC converter, the output end of the controller 10 is connected to n switch capacitor networks SC1~SC n control terminal.

[0049] In this embodiment, if Figure 3 As shown, each switched capacitor network SC i n output ports OUT1~OUT nArranged in order, n switched capacitor networks SC1~SC n The output ports at the same position in the n switched capacitor networks SC1 to SC n At the same position in each inductor L i Connect n switched capacitor networks SC1 to SC n An output port of the switch capacitor network SC1~SC n Output ports at different positions or with different port numbers to implement n switched capacitor networks SC1 to SC n The output end and n inductors L1~L n interwoven connections.

[0050] Taking a four-phase DCDC converter as an example, it includes four switched capacitor networks SC1-SC4 and four inductors L1-L4, wherein the inductor L1 is respectively connected to the output terminals OUT1, OUT2, OUT3 and OUT4 of the four switched capacitor networks SC1-SC4, the inductor L2 is respectively connected to the output terminals OUT2, OUT1, OUT4 and OUT3 of the four switched capacitor networks SC1-SC4, the inductor L3 is respectively connected to the output terminals OUT3, OUT4, OUT2 and OUT1 of the four switched capacitor networks SC1-SC4, and the inductor L4 is respectively connected to the output terminals OUT4, OUT3, OUT1 and OUT2 of the four switched capacitor networks SC1-SC4. This connection relationship is only an example, and other connection methods can also be used, as long as the positions of the output ports of the different switched capacitor networks connected to each inductor are different.

[0051] Generally, in order to better represent the connection relationship between the output terminal and the inductor of the switched capacitor network, the inductor connected to the output terminal OUT1 of the first switched capacitor network SC1 is used as the inductor L1, the inductor connected to the output terminal OUT2 of the first switched capacitor network SC1 is used as the inductor L2, and so on.

[0052] In each switched capacitor network SC i In the embodiment, n charging circuits are included, each charging circuit is set at an input end and a corresponding output end OUT i The first input terminal and the second input terminal of the controller 10 are used to detect any inductor L i The inductor current is based on any inductor L iThe charging stage is determined based on the relationship between the magnitude of the inductor current and multiple current thresholds to generate n groups of control signals corresponding to the charging stage. There is a preset phase difference between the n groups of control signals. Each group of control signals includes multiple control signals for controlling one charging circuit among the n charging circuits to be turned on and the other charging circuits to be turned off, so that the inductor connected to the turned-on charging circuit is in a charging state.

[0053] Among them, n groups of control signals are used to control the inductance L corresponding to each phase i The connected n switched capacitor networks SC1~SC n The charging circuit corresponding to the output end is turned on.

[0054] The phase difference is related to the number of phases of the multi-phase DCDC converter. For example, if the number of phases is 3, the phase difference of the three control signals is 360° / 3=120°. If the number of phases is 4, the phase difference of the four control signals is 360° / 4=90°.

[0055] For example, taking the number of phases as 3 as an example, the multi-phase DCDC converter includes 3 inductors, and the multi-phase DCDC converter includes three charging stages. In the first charging stage T ON1 , charging the inductor L1, the inductor L2 and the inductor L3 are in the discharge state, in the second charging stage T ON2 , charging the inductor L2, the inductor L1 and the inductor L3 are in the discharge state, in the third charging stage T ON3 , the inductor L3 is charged, and the inductor L1 and the inductor L2 are in a discharging state.

[0056] Taking the controller 10 detecting the inductor current at both ends of the inductor L1 as an example, when the rising edge of the clock signal comes, it is determined that the inductor L1 needs to be charged, and the generated n groups of control signals control the charging circuit corresponding to the output end connected to the inductor L1 to be turned on, entering the first charging stage T ON1 , the inductor L1 is charged, and the inductor current of the inductor L1 increases; when the inductor current of the inductor L1 is greater than the preset current threshold, the controller controls the charging circuit corresponding to the output terminal connected to the inductor L1 to be turned off, and the inductor L1 stops charging. The duty cycle of the charging process of the inductor L1 is determined, and the controller 10 copies the duty cycle to the second phase and the third phase with different phase differences. The n groups of control signals generated in the second phase control the charging circuit corresponding to the output terminal connected to the inductor L2 to be turned on, and enter the second charging stage T ON2 , charging the inductor L2, the n groups of control signals generated in the third phase control the charging circuit corresponding to the output end connected to the inductor L3 to be turned on, and the third charging stage T is entered. ON3 , charging the inductor L3.

[0057] After the inductor L1 stops charging, the discharge loop corresponding to the output terminal to which the inductor L1 is connected is turned on, and the inductor L1 starts discharging until the next clock rising edge signal arrives, at which time the inductor L1 starts charging again.

[0058] For the controller 10, no matter which inductor current is detected on which inductor, the duty cycle in the inductor charging process can be determined according to the size of the inductor current, so as to copy the duty cycle to different phases and control the corresponding inductor to charge in the corresponding phase.

[0059] The inductance L corresponding to each phase i During charging, the inductor L i The connected n switched capacitor networks SC1~SC n The charging circuit at the corresponding output end is turned on, and the inductor L i The total amount of charge obtained is n switch capacitor networks SC1~SC n The sum of the charges provided by the charging circuit at the corresponding output end. Due to the charge and discharge balance of the capacitors in the switched capacitor network, each switched capacitor network SC i The charges of the n charging loops are equal, so each inductor L i During the charging period, the n switched capacitor networks SC1 to SC n The charge obtained is Q1+Q2+…+Q n , where Q1 is the charge of each charging loop of the switched capacitor network SC1, Q2 is the charge of each charging loop of the switched capacitor network SC2, and Q n The switched capacitor network SC n The amount of charge in each charging circuit.

[0060] In some embodiments, each switched capacitor network SC i There is also a discharge loop between each output terminal and the ground. i During the non-charging period, each inductor L i The connected n switched capacitor networks SC1~SC n The discharge circuit corresponding to the output end is turned on, and the inductor L i Discharge.

[0061] Furthermore, each switched capacitor network SC i The discharge loop between the last output terminal and the ground can be omitted.

[0062] In the multi-phase DCDC converter provided by the above embodiment, one end of each inductor is respectively connected to the output ends of n switched capacitor networks at different positions, so that the output ends of the n switched capacitor networks are connected to the n inductors in an interlaced manner, and during each inductor charging period, an equal amount of charge is obtained through the n switched capacitor networks, thereby realizing automatic current sharing of the inductor current and improving the reliability of the multi-phase DCDC converter.

[0063] In a possible implementation, each switched capacitor network includes: n first power tubes, n-1 second power tubes and n-1 flying capacitors; wherein the n first power tubes are connected in series, the n-1 series nodes are respectively connected to one end of the n-1 flying capacitors, the other ends of the n-1 flying capacitors are respectively grounded through the n-1 second power tubes, and the other ends of the n-1 flying capacitors and the other end of the last first power tube serve as n output ends of each switched capacitor network.

[0064] Among them, each first power tube and the flying capacitor connected to it constitute a charging circuit of the switched capacitor network, the last first power tube alone serves as a charging circuit of the switched capacitor network, and the flying capacitor and each second power tube connected to it also constitute a discharging circuit of the switched capacitor network. When the inductor is in a charging state, the charging circuit corresponding to the output end connected to the inductor is turned on, and when the inductor is in a discharging state, the discharging circuit corresponding to the output end connected to the inductor is turned on. When one inductor is in a charging state, the other inductors are in a discharging state.

[0065] For example, Figure 4 A schematic diagram of the structure of a switched capacitor network provided in an embodiment of the present application is shown in FIG. Figure 4 As shown, taking the phase number n=3 as an example, the three first power tubes are respectively the power tube M1, the power tube M2 and the power tube M3, the two second power tubes are respectively the power tube M4 and the power tube M5, and the two flying capacitors are respectively the flying capacitor CF1 and the flying capacitor CF2, wherein the drain of the power tube M1 serves as the input end of the switch capacitor network, the source of the power tube M1 is connected to the upper plate of the flying capacitor CF1 and the drain of the power tube M2, the lower plate of the flying capacitor CF1 is connected to the drain of the power tube M4 as the output end OUT1 of the switch capacitor network, and the source of the power tube M4 is grounded; the source of the power tube M2 is connected to the upper plate of the flying capacitor CF2 and the drain of the power tube M3, the lower plate of the flying capacitor CF2 is connected to the drain of the power tube M5 as the output end OUT2 of the switch capacitor network, and the source of the power tube M5 is grounded; the source of the power tube M3 serves as the output end OUT3 of the switch capacitor network; the gates of the power tubes M1-M5 serve as the control ends of the switch capacitor network.

[0066] The above switch capacitor network is scaled down and then replicated n times to obtain n switch capacitor networks SC1 to SC nWhen the switch capacitor network is replicated and reduced in proportion, the size of the power tube and the size of the flying capacitor in the switch capacitor network are both reduced in proportion.

[0067] In one possible implementation, Figure 5 The principle framework of the multi-phase DCDC converter provided in the embodiment of the present application Figure 2 ,like Figure 5 As shown, the controller 10 may include: a control signal generating circuit 11 and n driving control circuits 12 .

[0068] The first input terminal and the second input terminal of the control signal generating circuit 11 serve as the first input terminal and the second input terminal of the controller 10 respectively, and the n output terminals of the control signal generating circuit 11 are connected to the control terminals of the n driving control circuits 12 respectively.

[0069] In this embodiment, the input terminal of the control signal generating circuit 11 is used to detect any inductor L i The inductor current is determined, and n groups of control signals are generated according to the size of the inductor current. The n groups of drive control signals are respectively transmitted to the n drive control circuits 12, wherein there are preset phase differences between the n groups of control signals.

[0070] Each group of control signals includes 2n-1 control signals, which correspond to the gate control terminals of 2n-1 power tubes in the switch capacitor network. There is a phase difference between the 2n-1 control signals to control different power tubes to be in different on or off states. After each drive control circuit 12 receives 2n-1 control signals, it performs corresponding level shifting on the 2n-1 control signals to raise the voltage domain of the digital signal to the drive voltage domain of the power tube. One charging circuit in the switch capacitor network is turned on, and the other charging circuits are turned off. The discharge circuit associated with the turned-on charging circuit is turned off, and the discharge circuit associated with the turned-off charging circuit is turned on.

[0071] In one possible implementation, Figure 6 The original circuit frame of the multi-phase DCDC converter provided in the embodiment of the present application Figure 3 ,like Figure 6 As shown, the control signal generating circuit 11 may include: a current detection module 112 , a hysteresis controller 113 , n−1 duty cycle replicators 114 and n switch signal generating modules 115 .

[0072] The first input terminal and the second input terminal of the current detection module 112 serve as the first input terminal and the second input terminal of the control signal generating circuit 11 respectively; the output terminal of the current detection module 112 is connected to the first input terminal of the hysteresis controller 113; the second input terminal of the hysteresis controller 113 is connected to the second input terminal of the current detection module 112; the first output terminal of the hysteresis controller 113 is connected to the input terminal of a switch signal generating module 115 and the first input terminal of n-1 duty cycle replicators 114; the second output terminal of the hysteresis controller 113 is connected to the second input terminal of the n-1 duty cycle replicators 114; the output terminal of the n-1 duty cycle replicators 114 is connected to the input terminal of the n-1 switch signal generating modules 115; the output terminal of the n switch signal generating modules 115 serves as the output terminal of the control signal generating circuit 11.

[0073] In this embodiment, the current detection module 112 is connected to any inductor L i The two ends of the inductor are used to detect any inductor L i The inductor current is detected and transmitted to the hysteresis controller 113. The hysteresis controller 113 performs error amplification and comparison on the inductor current to generate a phase signal Φ1. The hysteresis controller 113 is also used to compare the inductor current to generate a comparison signal. The phase signal Φ1 is passed through a switch signal generating module 115 to generate a set of control signals. The phase signal Φ1 and the comparison signal are respectively passed through n-1 duty cycle replicators 114 to generate n-1 phase signals Φ2 to Φ n , n-1 phase signals Φ2~Φ n n−1 groups of control signals are generated through n−1 switch signal generating modules 115 .

[0074] In one possible implementation, Figure 7 A circuit diagram of a multi-phase DCDC converter provided in an embodiment of the present application, such as Figure 7 As shown, taking the phase number of 3 as an example, Figure 7 As shown, the current detection module 112 includes: a detection resistor R S and detection capacitor C S , where the detection resistor R S One end of the current detection module 112 is used as the first input end, and is connected to any switch capacitor network SC i At the output end, the detection resistor R S The other end is connected to the detection capacitor C S One end of the current detection module 112 is used as the output end of the current detection module 112, and the detection capacitor C S The other end of the current detection module 112 is connected to the output end of the multi-phase DCDC converter as the second input end of the current detection module 112. S and detection capacitor C SThe current detection module 112 is used to detect any inductor L i The inductor current.

[0075] In one possible implementation, Figure 7 As shown, the hysteresis controller 113 includes: a differential amplifier 131 , a comparator 132 , an error amplifier EA, a first capacitor C1 , a first switch K1 , a compensation network 133 and a hysteresis comparator 134 .

[0076] The positive input terminal of the differential amplifier 131 serves as the first input terminal of the hysteresis controller 113, the negative input terminal of the differential amplifier 131 and the positive input terminal of the comparator 132 are connected as the second input terminal of the hysteresis controller 113, the output terminal of the differential amplifier 131 is connected to the positive input terminal of the hysteresis comparator 134 through the first capacitor C1, and the first switch K1 is connected in parallel on both sides of the first capacitor C1.

[0077] The input end of the compensation network 133 is connected to the positive input end of the comparator 132, the first output end of the compensation network 133 is connected to the negative input end of the error amplifier EA, and the second output end of the compensation network 133 is connected to the output end of the error amplifier EA and the negative input end of the hysteresis comparator 134; the output end of the hysteresis comparator 134 serves as the first output end of the hysteresis controller 113, the output end of the comparator 132 serves as the second output end of the hysteresis controller 113, and the negative input end of the comparator 132 and the positive input end of the error amplifier EA are connected to a preset reference voltage.

[0078] In this embodiment, Figure 8 The working waveform diagram of the hysteresis controller provided in the embodiment of the present application is as follows: Figure 8 As shown, after the differential amplifier 131 obtains the inductor current waveform, the output terminal is connected in series with the first capacitor C1 to obtain a signal V RAMP , as the positive input of the hysteresis comparator 134. The error amplifier EA outputs the voltage V OUT and reference voltage V REF After the difference is amplified, the signal V EA , as the negative input of the hysteresis comparator 134. The hysteresis comparator 134 converts the signal V RAMP With V EA For comparison, when V RAMP Less than V EA When Φ1 is high, when V RAMP Greater than V EA When Φ1 is low, each cycle V RAMP Pulled low by the rising edge of the clock signal CLK.

[0079] The comparator 132 outputs the voltage V OUT and reference voltage V REFLThe comparison is performed and the comparison result is also input into the duty cycle replicator 114. Subsequently, the duty cycle replicator 114 replicates Φ1 with different phase differences based on the comparison result to obtain Φ2 to Φ n .

[0080] In one possible implementation, Figure 7 As shown, the compensation network 133 includes: a first resistor R1, a second resistor R2, a second capacitor C2 and a third capacitor C3.

[0081] The first resistor R1 and the second capacitor C2 are connected in parallel, one end of the parallel connection serves as the input end of the compensation network 133, the other end of the parallel connection serves as the first output end of the compensation network 133, and the other end of the parallel connection is also connected to the second resistor R2 and one end of the third capacitor C3 in sequence, and the other end of the third capacitor C3 serves as the second output end of the compensation network 133.

[0082] In this embodiment, the first resistor R1, the second resistor R2, the second capacitor C2 and the third capacitor C3 are responsible for the stability of the system.

[0083] In one possible implementation, Figure 7 As shown, the control signal generating circuit 11 may further include: n selectors 116 .

[0084] The 0 input terminals of the n selectors 116 are connected to the flying capacitor power-on controller start-up, the 1 input terminals of the n selectors 116 are respectively connected to the output terminals of the n switch signal generating modules 115 , and the output terminals of the n selectors 116 serve as the output terminals of the control signal generating circuit 11 .

[0085] In this embodiment, when the flying capacitor power-on controller start-up provides a power-on control signal, the n selectors 116 select to output the power-on control signal to control the flying capacitor on the switch capacitor network to power on. When the flying capacitor power-on controller start-up does not provide a power-on control signal, the n selectors 116 select to output the control signal to control the switch capacitor network to charge and discharge the inductor.

[0086] In one possible implementation, Figure 7 As shown, each driving control circuit 12 may include: n first gate drivers 121 , n−1 second gate drivers 122 , and n level shifters 123 .

[0087] Each output end of the control signal generating circuit 11 is connected to the input ends of n level shifters 123 and the input ends of n-1 second gate drivers 122 in the corresponding drive control circuit 12, the output ends of the n level shifters 123 are connected to the input ends of n first gate drivers 122, and the output ends of the n first gate drivers 121 and the output ends of the n-1 second gate drivers 122 are connected to the control end of a switch capacitor network.

[0088] The level shifter 123 is used to raise the voltage of the digital control signal provided by the control signal generating circuit 11 to the voltage domain of the power tube, so as to control the power tube corresponding to the charging circuit to be turned on and charged, while the power tube located in the discharge circuit only needs to be controlled by a high-level control signal to be turned on, and there is no need to set the level shifter 123.

[0089] For example, Fig. 9 The working principle diagram provided for the embodiment of the present application is combined with Figure 7 and Fig. 9 , the working principle of the multi-phase DCDC converter is explained.

[0090] Take three phases as an example, Figure 7 As shown, the current detection module 112 detects any inductor L i The inductor current is transmitted to the hysteresis controller 113, and the phase signal Φ1 is generated through error amplification and comparison of the hysteresis controller 113. The hysteresis controller 113 is also used to compare the inductor current to generate a comparison signal. The phase signal Φ1 is passed through a switch signal generating module 115 to generate a set of control signals S 11 ~S 15 The phase signal Φ1 and the comparison signal are respectively passed through n-1 duty cycle replicators 114 to generate n-1 phase signals Φ2 to Φ n , n-1 phase signals Φ2~Φ n n−1 groups of control signals are generated through n−1 switch signal generating modules 115 .

[0091] Each group of control signals passes through the level shifter and the gate driver to control the corresponding power tube to turn on or off.

[0092] like Fig. 9 As shown, in the first charging stage T ON1 , the inductor L1 is charged, the charging loop P1 of the switched capacitor network SC1, the charging loop P3 of the switched capacitor network SC2, and the charging loop P2 of the switched capacitor network SC3 are turned on, providing charge to the inductor L1, and the total charge obtained by the inductor L1 is Q 11 +Q 23 +Q 32 In the next stage, all inductors are discharged. The second charging stage T ON2In the first charging stage, T ON1 Similarly, the inductor L2 is charged, the charging loop P2 of the switched capacitor network SC1, the charging loop P1 of the switched capacitor network SC2, and the charging loop P2 of the switched capacitor network SC3 are turned on, providing charge to the inductor L2, and the charge obtained by the inductor L2 is Q 12 +Q 21 +Q 33 In the third charging stage T ON3 , the charging loop P3 of the switched capacitor network SC1, the charging loop P2 of the switched capacitor network SC2, and the charging loop P1 of the switched capacitor network SC3 are turned on, providing charge to the inductor L3, and the charge obtained by the inductor L3 is Q 13 +Q 22 +Q 31 Because the charge and discharge of the capacitor in the switched capacitor network SC1 is balanced, Q1 = Q 11 =Q 12 =Q 13 , the same is true for the switched capacitor networks SC2 and SC3, so in one cycle, the amount of charge each inductor receives from the switched capacitor network is equal to Q1+Q2+Q3. Although the charge between each switch network is different, the total amount of charge received by the inductor is always equal, thus achieving the effect of automatic current sharing of the inductor current.

[0093] In one possible implementation, Figure 7 As shown, the first first power tube and n-1 second power tubes among the n first power tubes are CMOS tubes, and the remaining first power tubes are LDMOS tubes.

[0094] For example, Fig.10 The following is a schematic diagram of the steady-state working test results provided by the embodiment of the present application, as shown in FIG. Fig.10 As shown, the waveforms of the output ends of each switch network node, i.e., the switch nodes, and the inductor current waveforms when the multi-phase DCDC converter provided by the present application is in steady-state operation. It can be seen that the multi-phase DCDC converter achieves automatic current sharing of the inductor current when the duty cycle D overlaps or does not overlap.

[0095] Based on the multi-phase DCDC converter provided in the above embodiments, an embodiment of the present application further provides a switching power supply, which includes the multi-phase DCDC converter in any of the above embodiments.

[0096] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A multi-phase DCDC converter, characterized in that: The multi-phase DCDC converter comprises: n switched capacitor networks, n inductors and a controller, wherein each switched capacitor network comprises n output terminals arranged in sequence, and the number of phases of the multi-phase DCDC converter is n; The input ends of the n switched capacitor networks receive input voltages, one end of each inductor is respectively connected to output ends at different positions of the n switched capacitor networks, the other ends of the n inductors are connected as the output end of the multi-phase DCDC converter, the first input end and the second input end of the controller are respectively connected to any output end of the n switched capacitor networks and the output end of the multi-phase DCDC converter, and the output end of the controller is connected to the control end of the n switched capacitor networks.

2. The multi-phase DCDC converter according to claim 1, wherein: Each of the switch capacitor networks comprises: n first power tubes, n-1 second power tubes and n-1 flying capacitors; Among them, n first power tubes are connected in series, n-1 series nodes are respectively connected to one end of the n-1 flying capacitors, the other ends of the n-1 flying capacitors are respectively grounded through n-1 second power tubes, and the other ends of the n-1 flying capacitors and the other end of the last first power tube serve as n output ends of each switch capacitor network.

3. The multi-phase DCDC converter according to claim 1, wherein: The controller comprises: a control signal generating circuit and n driving control circuits; The first input terminal and the second input terminal of the control signal generating circuit serve as the first input terminal and the second input terminal of the controller respectively, and the n output terminals of the control signal generating circuit are respectively connected to the control terminals of the n driving control circuits.

4. The multi-phase DCDC converter according to claim 3, characterized in that: The control signal generating circuit comprises: a current detection module, a hysteresis controller, n-1 duty cycle replicators and n switch signal generating modules; The first input end and the second input end of the current detection module serve as the first input end and the second input end of the control signal generating circuit respectively; the output end of the current detection module is connected to the first input end of the hysteresis controller; the second input end of the hysteresis controller is connected to the second input end of the current detection module; the first output end of the hysteresis controller is connected to the input end of a switch signal generating module and the first input end of n-1 duty cycle replicators; the second output end of the hysteresis controller is connected to the second input end of the n-1 duty cycle replicators; and the output end of the n-1 duty cycle replicators is connected to the input end of the n-1 switch signal generating module; The output ends of the n switch signal generating modules serve as the output ends of the control signal generating circuit.

5. The multi-phase DCDC converter according to claim 4, characterized in that: The hysteresis controller includes: a differential amplifier, a comparator, an error amplifier, a first capacitor, a first switch, a compensation network and a hysteresis comparator; The positive input terminal of the differential amplifier is used as the first input terminal of the hysteresis controller, the negative input terminal of the differential amplifier and the positive input terminal of the comparator are connected as the second input terminal of the hysteresis controller, the output terminal of the differential amplifier is connected to the positive input terminal of the hysteresis comparator through the first capacitor, and the first switch is connected in parallel to both sides of the first capacitor; The input end of the compensation network is connected to the positive input end of the comparator, the first output end of the compensation network is connected to the negative input end of the error amplifier, and the second output end of the compensation network is connected to the output end of the error amplifier and the negative input end of the hysteresis comparator; The output end of the hysteresis comparator serves as the first output end of the hysteresis controller, the output end of the comparator serves as the second output end of the hysteresis controller, and the negative input end of the comparator and the positive input end of the error amplifier are connected to a preset reference voltage.

6. The multi-phase DCDC converter according to claim 5, characterized in that: The compensation network includes: a first resistor, a second resistor, a second capacitor and a third capacitor; The first resistor and the second capacitor are connected in parallel, one end of the parallel connection serves as the input end of the compensation network, the other end of the parallel connection serves as the first output end of the compensation network, and the other end of the parallel connection is also connected to the second resistor and one end of the third capacitor in sequence, and the other end of the third capacitor serves as the second output end of the compensation network.

7. The multi-phase DCDC converter according to claim 4, wherein: The control signal generating circuit further includes: n selectors; The 0 input ends of the n selectors are connected to the flying capacitor power-on controller, the 1 input ends of the n selectors are respectively connected to the output ends of the n switch signal generating modules, and the output ends of the n selectors serve as the output ends of the control signal generating circuit.

8. The multi-phase DCDC converter according to claim 3, wherein: Each driving control circuit includes: n first gate drivers, n-1 second gate drivers and n level shifters; Each output end of the control signal generating circuit is connected to the input ends of n level shifters and the input ends of n-1 second gate drivers in the corresponding drive control circuit, the output ends of the n level shifters are connected to the input ends of n first gate drivers, and the output ends of the n first gate drivers and the output ends of the n-1 second gate drivers are connected to the control end of a switch capacitor network.

9. The multi-phase DCDC converter according to claim 2, wherein: The first first power tube among the n first power tubes and the n-1 second power tubes are CMOS tubes, and the remaining first power tubes are LDMOS tubes.

10. A switching power supply, characterized in that: The switching power supply comprises a multi-phase DCDC converter as claimed in any one of claims 1 to 9.

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