Multi-phase switching power supply and control circuit and method thereof

Abstract

The application provides a multi-phase switching power supply, a control circuit and a control method thereof. The multi-phase switching power supply comprises N-phase power conversion circuits. The control circuit obtains a first compensation signal according to an original compensation signal and a first coefficient, obtains a current reference signal corresponding to each phase power conversion circuit according to the first compensation signal and a first signal, and controls each start-up phase power conversion circuit to provide power output to a load according to the current reference signal corresponding to each start-up phase power conversion circuit, so that the first compensation signal is consistent with the first signal in a steady state. The original compensation signal is obtained based on error amplification of an output feedback signal of the multi-phase switching power supply and a preset reference voltage. The first coefficient represents ratio information of N and the number of phases of the start-up power conversion circuit. The first signal represents average inductance current information of the first phase power conversion circuit. The number of start-up phases can be quickly responded, and the application can be applied to occasions with thermal balance requirements.

Description

Technical Field

[0001] This invention relates to the field of power electronics technology, and in particular to a multiphase switching power supply and its control circuit and control method. Background Technology

[0002] Multiphase switching power supplies are widely used in CPUs, GPUs, artificial intelligence, and other fields. Figure 1 The diagram shows a circuit block diagram of a conventional multiphase switching power supply 10 in the prior art. The multiphase switching power supply 10 includes N-phase parallel coupled power conversion circuits 101 to 10N and a control circuit 100, where N is an integer greater than 1. Each phase power conversion circuit includes a driver, a switch T1, a switch T2, and an inductor L01. Switch T1 and switch T2 are connected between the input voltage Vin and the reference ground. Inductor L01 is connected between the common terminal of switch T1 and switch T2 and the output terminal of the multiphase switching power supply 10. The control circuit 100 includes an output feedback circuit 120 and a control module 110. The output feedback circuit 120 generates an original compensation signal Vc based on the error amplification of the output feedback signal FB and a preset reference voltage. The control module 110 includes N control units 111 to 11N. Each control unit 111 to 11N uses the original compensation signal Vc as the current reference signal for its respective phase, and then generates control signals PWM1 to PWMN for each phase power conversion circuit 101 to 10N according to the current reference signal Vc. Each driver in the power conversion circuit 101 to 10N receives its corresponding control signal to control the switching on and off of the switch T1 and switch T2 for its respective phase.

[0003] To improve efficiency, the number of phases of the power conversion circuit during startup needs to be controlled based on factors such as the load current (i.e., the number of phases of the power conversion circuit operating in power mode, hereinafter referred to as the startup phase number). Figure 1 The multiphase switching power supply 10 shown cannot respond quickly when the number of phases changes during startup. To address this prior art problem, one existing solution is as follows: Figure 2As shown, the multiphase switching power supply 20 adds a voltage conversion circuit 230, an average signal generation circuit 240, and a current reference signal generation circuit 250 to the multiphase switching power supply 10. The voltage conversion circuit 230 receives the original compensation signal Vc and outputs a first compensation signal Vc1, where Vc1 = Vc × N / Nact, and Nact represents the number of starting phases. The average signal generation circuit 240 outputs an average signal Vavg that represents the quotient of the output current io and N (i.e., io / N). The current reference signal generation circuit 250 obtains an adjustment voltage based on the original compensation signal Vc and the average signal Vavg, and superimposes the first compensation signal Vc1 and the adjustment voltage to obtain a signal Vcp. Each control unit uses the signal Vcp as the current reference signal for its respective phase. When the multiphase switching power supply 20 reaches a stable state, the original compensation signal Vc and the average signal Vavg are consistent. Since the first compensation signal Vc1 can change rapidly with the change of the number of starting phases Nact when the number of starting phases Nact changes, it is possible to quickly adjust the inductor current of the power conversion circuit of each starting phase when the number of starting phases changes.

[0004] However, since the original compensation signal Vc and the average signal Vavg of the multiphase switching power supply 20 are consistent in the steady state, it can only be used in situations with current sharing requirements (i.e., the average inductor current of each power conversion circuit of the start-up phase must be consistent), and cannot be extended to situations with thermal balance requirements. Therefore, it is necessary to propose a new control circuit, control method and multiphase switching power supply that can solve the technical problem of not being able to respond quickly to changes in the number of start-up phases. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide a control circuit, control method and multiphase switching power supply for a multiphase switching power supply, so as to solve the technical problem that the prior art cannot respond quickly to changes in the number of starting phases.

[0006] The technical solution of the present invention is, on the one hand, to provide a control circuit for a multi-phase switching power supply, wherein the multi-phase switching power supply includes an N-phase power conversion circuit, where N is the number of phases of the power conversion circuit configured in the multi-phase switching power supply, and N is an integer greater than 1.

[0007] The control circuit is configured to obtain a first compensation signal based on the original compensation signal and a first coefficient, obtain a current reference signal for each phase power conversion circuit based on the first compensation signal and a first signal, and control each start-up phase power conversion circuit to provide power output to the load based on the current reference signal for each start-up phase power conversion circuit, so that the first compensation signal is consistent with the first signal in a stable state.

[0008] The original compensation signal is obtained by amplifying the error between the output feedback signal of the multiphase switching power supply and a preset reference voltage. The first coefficient represents the ratio information of N and Nact, where Nact is the number of phases of the power conversion circuit started by the multiphase switching power supply and Nact is a positive integer less than or equal to N. The first signal represents the average inductor current information of the first phase power conversion circuit in the N-phase power conversion circuit.

[0009] Optionally, the control circuit includes:

[0010] A first voltage conversion unit receives the original compensation signal and is configured to perform voltage conversion on the original compensation signal according to the first coefficient to obtain the first compensation signal.

[0011] The current reference signal generation module receives the first compensation signal and the first signal, and is configured to obtain a first adjustment voltage based on the first compensation signal and the first signal, and to superimpose the first compensation signal and the first adjustment voltage to obtain a current reference signal corresponding to each phase power conversion circuit.

[0012] The control module is configured to obtain control signals for each startup phase power conversion circuit based on the current reference signal of each startup phase power conversion circuit, so as to control each startup phase power conversion circuit to provide power output to the load.

[0013] Optionally, the first compensation signal is equal to the product of the original compensation signal and the first coefficient.

[0014] Optionally, when the first compensation signal is greater than the first signal, the first adjustment voltage is increased;

[0015] When the first compensation signal is less than the first signal, the first adjustment voltage decreases.

[0016] Optionally, the current reference signal generation module includes:

[0017] The first adjustment unit receives the first compensation signal and the first signal, and outputs an adjustment signal according to the first compensation signal and the first signal.

[0018] The superposition unit is configured to obtain the first adjustment voltage based on the adjustment signal, and to superimpose the first compensation signal and the first adjustment voltage to obtain the current reference signal corresponding to each phase power conversion circuit.

[0019] Optionally, the superposition unit is configured to superimpose the first compensation signal and the first adjustment voltage to obtain a first current reference signal, and use the first current reference signal as the current reference signal corresponding to the N-phase power conversion circuit.

[0020] Optionally, the superposition unit is configured to superimpose the first compensation signal and the first adjustment voltage to obtain a first current reference signal, and use the first current reference signal as the current reference signal corresponding to the first phase power conversion circuit; and,

[0021] The j-th current reference signal is obtained by superimposing the first compensation signal, the first adjustment voltage, and the j-th coefficient, and is used as the current reference signal for the corresponding j-th phase power conversion circuit.

[0022] Wherein, the j-th coefficient represents the ratio of the target value of the average inductor current of the j-th phase power conversion circuit to the average inductor current of the 1-th phase power conversion circuit, and j is any integer greater than or equal to 2 and less than or equal to N.

[0023] Optionally, when the multiphase switching power supply is in a stable state, the average inductor current of the j-th phase power conversion circuit is consistent with the product of the average inductor current of the 1-th phase power conversion circuit and the j-th coefficient.

[0024] Optionally, the superposition unit is further configured to obtain a j-th compensation signal based on the first compensation signal and the j-th coefficient, and to superimpose the j-th compensation signal and the first adjustment voltage to obtain the j-th current reference signal.

[0025] Wherein, the j-th compensation signal is equal to the product of the first compensation signal and the j-th coefficient.

[0026] Optionally, the superposition unit includes a second voltage conversion unit to an Nth voltage conversion unit.

[0027] The j-th voltage conversion unit receives the first compensation signal and is configured to perform voltage conversion on the first compensation signal according to the j-th coefficient to obtain the j-th compensation signal.

[0028] Optionally, the j-th coefficient is set according to the heat dissipation conditions of the first phase power conversion circuit and the j-th phase power conversion circuit to achieve thermal balance of each start-up phase power conversion circuit.

[0029] Secondly, the present invention also provides a control method for a multiphase switching power supply, wherein the multiphase switching power supply includes an N-phase power conversion circuit, where N is the number of phases of the power conversion circuit configured in the multiphase switching power supply, and N is an integer greater than 1. The control method includes:

[0030] The output feedback signal of the multiphase switching power supply is amplified with respect to a preset reference voltage to obtain the original compensation signal.

[0031] The first compensation signal is obtained based on the original compensation signal and the first coefficient;

[0032] Based on the first compensation signal and the first signal, the current reference signal for each phase power conversion circuit is obtained, and each start-up phase power conversion circuit is controlled to provide power output to the load based on the current reference signal for each start-up phase power conversion circuit, so that the first compensation signal and the first signal are consistent under steady state.

[0033] Wherein, the first coefficient represents the ratio information of N and Nact, Nact is the number of phases of the power conversion circuit started by the multiphase switching power supply, Nact is a positive integer less than or equal to N, and the first signal represents the average inductor current information of the first phase power conversion circuit in the N-phase power conversion circuit.

[0034] Optionally, the method for obtaining the current reference signal corresponding to each phase power conversion circuit based on the first compensation signal and the first signal includes:

[0035] A first adjustment voltage is obtained based on the first compensation signal and the first signal;

[0036] The current reference signal for each phase power conversion circuit is obtained by superimposing the first compensation signal and the first adjustment voltage.

[0037] Optionally, the method for superimposing the first compensation signal and the first adjustment voltage to obtain the current reference signal corresponding to each phase power conversion circuit includes:

[0038] The first compensation signal and the first adjustment voltage are superimposed to obtain a first current reference signal, and the first current reference signal is used as the current reference signal corresponding to the N-phase power conversion circuit.

[0039] Optionally, the method for superimposing the first compensation signal and the first adjustment voltage to obtain the current reference signal corresponding to each phase power conversion circuit includes:

[0040] The first compensation signal and the first adjustment voltage are superimposed to obtain a first current reference signal, and the first current reference signal is used as the current reference signal corresponding to the first phase power conversion circuit; and,

[0041] The j-th current reference signal is obtained by superimposing the first compensation signal, the first adjustment voltage, and the j-th coefficient, and is used as the current reference signal for the corresponding j-th phase power conversion circuit.

[0042] Wherein, the j-th coefficient represents the ratio of the target value of the average inductor current of the j-th phase power conversion circuit to the average inductor current of the 1-th phase power conversion circuit, and j is any integer greater than or equal to 2 and less than or equal to N.

[0043] Thirdly, the present invention also provides a multiphase switching power supply, the multiphase switching power supply including an N-phase power conversion circuit and the control circuit described above, wherein N is the number of phases of the power conversion circuit configured in the multiphase switching power supply, and N is an integer greater than 1.

[0044] Compared with the prior art, the present invention obtains a first compensation signal based on the original compensation signal and a first coefficient, obtains a current reference signal for each phase power conversion circuit based on the first compensation signal and a first signal, and controls each start-up phase power conversion circuit to provide power output to the load based on the current reference signal for each start-up phase power conversion circuit, so that the first compensation signal is consistent with the first signal in a stable state. It can quickly adjust the inductor current of each start-up phase power conversion circuit when the number of start-up phases changes, and can be extended to applications with thermal balance requirements. Attached Figure Description

[0045] Figure 1 This is a schematic diagram of a circuit block diagram of a multiphase switching power supply in the prior art;

[0046] Figure 2 This is a schematic diagram of a circuit block diagram for another type of multiphase switching power supply in the prior art.

[0047] Figure 3 This is a schematic circuit block diagram of a multiphase switching power supply according to an embodiment of the present invention.

[0048] Figure 4 According to Figure 3 A schematic diagram of the current reference signal generation module in the first embodiment;

[0049] Figure 5 According to Figure 3 A schematic diagram of the current reference signal generation module in the second embodiment;

[0050] Figure 6 This is a schematic circuit block diagram of another multiphase switching power supply according to an embodiment of the present invention;

[0051] Figure 7 According to Figure 6A schematic diagram of the current reference signal generation module in the third embodiment;

[0052] Figure 8 This is a schematic diagram of the structure of the first signal generation unit according to an embodiment of the present invention;

[0053] Figure 9 This is a flowchart illustrating a control method for a multiphase switching power supply according to an embodiment of the present invention. Detailed Implementation

[0054] The preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings, but the present invention is not limited to these embodiments. The present invention covers any substitutions, modifications, equivalent methods, and solutions made within the spirit and scope of the present invention.

[0055] To provide the public with a thorough understanding of the present invention, specific details are described in detail in the following preferred embodiments of the invention, but those skilled in the art can fully understand the invention without these details.

[0056] The invention is described in more detail below by way of example with reference to the accompanying drawings. It should be noted that the drawings are in a simplified form and use non-precise proportions, and are only used to facilitate and clarify the illustration of the embodiments of the invention.

[0057] Figure 3 A circuit block diagram of a multiphase switching power supply 30 according to an embodiment of the present invention is shown. The multiphase switching power supply 30 receives an input voltage Vin and performs power conversion to generate an output voltage Vo and an output current io, which are provided to the load. It includes N-phase parallel-coupled power conversion circuits 301-30N, a control circuit 300, and an output capacitor Cout. N is the number of phases of the power conversion circuits configured in the multiphase switching power supply 30 (hereinafter referred to as the configured phase number), and N is an integer greater than 1. The output capacitor Cout is connected between the output terminal of the multiphase switching power supply 30 and a reference ground. The circuit structure of the power conversion circuits 301-30N can be referred to... Figure 1The present invention is understood in relation to the power conversion circuit 101, but does not limit the topology used in the power conversion circuits 301-30N. Topologies such as boost, flyback, and buck-boost can also be used. The control circuit 300 is configured to obtain a first compensation signal Vc1 based on the original compensation signal Vc and a first coefficient (denoted as N / Nact), obtain a first current reference signal Vcp1 based on the first compensation signal Vc1 and a first signal V1, and use the first current reference signal Vcp1 as the current reference signal for each corresponding phase power conversion circuit. Based on the current reference signal for each corresponding start-up phase power conversion circuit, the control circuit provides power output to the load, so that when the multi-phase switching power supply 30 reaches a stable state, the first compensation signal Vc1 is consistent with the first signal V1. The terms "to" represent equal or very close. The original compensation signal Vc is obtained by amplifying the error between the output feedback signal FB of the multiphase switching power supply 30 and a preset reference voltage. The first coefficient represents the ratio information of N and Nact, where Nact is the number of phases of the power conversion circuit started by the multiphase switching power supply 30 (hereinafter referred to as the number of start-up phases). Nact is a positive integer less than or equal to N. The first signal V1 represents the average inductor current information of the first phase power conversion circuit 301, that is, the first signal V1 represents the average value information of the inductor current i1 of the first phase power conversion circuit 301.

[0058] It should be noted that the first phase power conversion circuit in this application is for ease of description and does not restrict the specific location of the phase; the first phase can be any one of the N phases. Similarly, the j-th phase power conversion circuit and the N-th phase power conversion circuit mentioned later are also for ease of description and do not restrict the specific location of the phase.

[0059] Further, refer to Figure 3 The control circuit 300 includes an output feedback circuit 320, a first voltage conversion unit 330, a first signal generation unit 340, a current reference signal generation module 350, and a control module 310.

[0060] The output feedback circuit 320 receives an output feedback signal FB representing the output voltage Vo of the multiphase switching power supply 30, and amplifies the error between the output feedback signal FB and the reference voltage to obtain the original compensation signal Vc. Exemplarily, the output feedback circuit 320 includes, for example, an error amplifier circuit and a compensation circuit (not shown in the figure). The first input terminal of the error amplifier circuit receives the output feedback signal FB, the second input terminal receives the reference voltage, and the output terminal is connected to the compensation circuit and outputs the original compensation signal Vc.

[0061] The first voltage conversion unit 330 receives the original compensation signal Vc and is configured to perform voltage conversion on the original compensation signal Vc according to a first coefficient (N / Nact) to obtain a first compensation signal Vc1. Exemplarily, the first voltage conversion unit 330 can be configured to obtain the first compensation signal Vc1 based on the configured phase number N, the start-up phase number Nact, and the original compensation signal Vc, such that Vc1 = Vc × (N / Nact). The start-up phase number Nact is less than or equal to the configured phase number N, and the first coefficient (N / Nact) is greater than or equal to 1.

[0062] The first signal generation unit 340 is used to generate the aforementioned first signal. In some possible embodiments, refer to... Figure 8 The first signal generation unit 340 receives a first inductor current sampling signal CS1 that characterizes the inductor current i1 of the first phase power conversion circuit 301, and performs averaging processing (such as filtering) on ​​the first inductor current sampling signal CS1 to output a first signal V1. As a further example, the first signal generation unit 340 includes a filtering circuit composed of a resistor R01 and a capacitor C01.

[0063] The current reference signal generation module 350 receives a first compensation signal Vc1 and a first signal V1, and is configured to obtain a first adjustment voltage based on the first compensation signal and the first signal, and to superimpose the first compensation signal and the first adjustment voltage to obtain a first current reference signal Vcp1. In some possible embodiments, the current reference signal generation module 350 may be further configured to increase the first adjustment voltage when the first compensation signal Vc1 is greater than the first signal V1, and decrease the first adjustment voltage when the first compensation signal Vc1 is less than the first signal V1, so as to achieve dynamic adjustment of the first adjustment voltage based on the first compensation signal and the first signal, thereby achieving dynamic balance between the first compensation signal Vc1 and the first signal V1. For example, the current reference signal generation module 350 includes a first adjustment unit 351 and a superposition unit 352. The first adjustment unit 351 outputs an adjustment signal based on a first compensation signal Vc1 and a first signal V1. The superposition unit 352 is configured to obtain a first adjustment voltage based on the adjustment signal, and to superimpose the first compensation signal Vc1 and the first adjustment voltage to obtain a first current reference signal Vcp1, and to use the first current reference signal Vcp1 as the current reference signal for the corresponding N-phase power conversion circuits 301-30N.

[0064] The control module 310 is configured to obtain control signals for each start-up phase power conversion circuit based on the first current reference signal Vcp1, so as to control each start-up phase power conversion circuit to provide power output to the load. For example, the control module 310 includes N control units 311 to 31N, corresponding one-to-one with N phase power conversion circuits 301 to 30N. Control units 311 to 31N are used to output control signals PWM1 to PWMN. Each control unit corresponding to the start-up phase power conversion circuit is configured to generate a peak current reference signal and / or a valley current reference signal for the corresponding phase power conversion circuit based on the first current reference signal Vcp1, and obtain the control signal for the corresponding phase power conversion circuit based on the peak current reference signal and / or valley current reference signal of the corresponding phase power conversion circuit, and the inductor current sampling signal of the corresponding phase power conversion circuit. For example, in one embodiment, the first current reference signal Vcp1 can be used as the peak current reference signal for each phase power conversion circuit. Since the first current reference signal Vcp1 is used as the current reference signal for each phase, the average inductor current of each start-up phase can be made consistent.

[0065] Figure 4 and Figure 5 They respectively showed according to Figure 3 The circuit structure diagrams of the current reference signal generation module 350 in the first and second embodiments are shown below. (Refer to...) Figure 4 and Figure 5 In some possible embodiments, the first adjustment unit 351 includes an operational amplifier U1 and a first capacitor Cc. The first input terminal of the operational amplifier U1 receives a first compensation signal Vc1, the second input terminal receives a first signal V1, and the output terminal outputs an adjustment signal. The first capacitor Cc is connected between the output terminal of the operational amplifier U1 and a reference ground for integration. Of course, in other embodiments, the first adjustment unit 351 may also include a comparator. The first input terminal of the comparator receives the first compensation signal Vc1, the second input terminal receives the first signal Vc, and the output terminal outputs an adjustment signal. In Embodiment 1, as... Figure 4 As shown, the superposition unit 352 uses the adjustment signal as the first adjustment voltage ΔVc, and includes a first adder circuit A1. The first input terminal receives the first compensation signal Vc1, and the second input terminal receives the first adjustment voltage ΔVc. It performs an addition operation on the first compensation signal Vc1 and the first adjustment voltage ΔVc to output a first current reference signal Vcp1 at its output terminal. It is readily understood that in some other embodiments, the superposition unit 352 may also generate a first adjustment voltage ΔVc different from the adjustment signal based on the adjustment signal, and then use the adder circuit to obtain the first current reference signal Vcp1. In Embodiment Two, as... Figure 5As shown, the superposition unit 352 includes a current generating circuit 3521 and a first resistor Rc. The current generating circuit 3521 receives an adjustment signal and generates a first current signal according to the adjustment signal. The first end of the first resistor Rc is connected to the current generating circuit 3521 to receive the first current signal, and the second end receives the first compensation signal Vc1. The voltage difference across the first resistor Rc is the first adjustment signal ΔVc. The superposition unit 352 outputs a first current reference signal Vcp1 at the first end of the first resistor Rc, which means that the first compensation signal Vc1 and the first adjustment signal ΔVc are superimposed to obtain the first current reference signal Vcp1.

[0066] In conclusion, in such cases... Figures 3 to 5 In the illustrated embodiment, since the first compensation signal Vc1 changes rapidly with the change in the number of starting phases Nact when the number of starting phases Nact changes, and the current reference signal of each starting phase power conversion circuit is obtained based on the first compensation signal Vc1, rapid adjustment of the inductor current of each starting phase power conversion circuit can be achieved when the number of starting phases changes. Furthermore, by dynamically adjusting the first adjustment voltage according to the first compensation signal and the first signal, consistency between the first compensation signal and the first signal can be achieved in a stable state. Since the first current reference signal Vcp1 is used as the current reference signal for each phase, the average inductor current of each starting phase power conversion circuit can be made equal in a stable state.

[0067] Figure 6A schematic circuit block diagram of another multiphase switching power supply 40 according to an embodiment of the present invention is shown. The circuit block diagram of the multiphase switching power supply 40 is basically the same as that of the multiphase switching power supply 30, and will not be described again here. The main difference is that the control circuit 400 in the multiphase switching power supply 40 is configured to obtain a first compensation signal Vc1 based on the original compensation signal Vc and a first coefficient (denoted as N / Nact), obtain a first current reference signal Vcp1 to a first current reference signal VcpN based on the first compensation signal Vc1 and a first signal V1, and use the first current reference signal Vcp1 to the Nth current reference signal VcpN as the current reference signals corresponding to the first phase power conversion circuit 401 to the Nth phase power conversion circuit 40N, respectively. The control circuit of each starting phase power conversion circuit provides power output to the load according to the current reference signal corresponding to each starting phase power conversion circuit, so that the first compensation signal Vc1 is consistent with the first signal V1 when the multiphase switching power supply 40 reaches a stable state. Further, the current reference signal generation module 450 in the control circuit 400 receives a first compensation signal Vc1 and a first signal V1, and is configured to obtain a first adjustment voltage based on the first compensation signal and the first signal, and to superimpose the first compensation signal and the first adjustment voltage to obtain a first current reference signal Vcp1 to an Nth current reference signal VcpN; and each control unit in the control units 411 to 41N corresponding to the activated phase power conversion circuit is configured to obtain a control signal for the corresponding phase power conversion circuit based on the current reference signal of the corresponding phase power conversion circuit. In some possible embodiments, the current reference signal generation module 450 may be further configured to increase the first adjustment voltage when the first compensation signal Vc1 is greater than the first signal V1, and decrease the first adjustment voltage when the first compensation signal Vc1 is less than the first signal V1.

[0068] Figure 7 It shows that according to Figure 6The circuit structure diagram of the current reference signal generation module 450 in the third embodiment is shown below. The current reference signal generation module 450 includes a first adjustment unit 451 and a superposition unit 452. The first adjustment unit 451 can be referred to the previous description of the first adjustment unit 351, and will not be repeated here. The superposition unit 452 is configured to superimpose the first compensation signal Vc1 and the first adjustment voltage ΔVc to obtain a first current reference signal Vcp1; and to superimpose the first compensation signal Vc1, the first adjustment voltage ΔVc and the j-th coefficient to obtain a j-th current reference signal Vcpj, wherein the j-th coefficient represents the ratio information of the average inductor current target value of the j-th phase power conversion circuit to the average inductor current of the 1-th phase power conversion circuit, and j is any integer greater than or equal to 2 and less than or equal to N. In this embodiment, by configuring the superposition unit 452 to superimpose the first compensation signal Vc1, the first adjustment voltage ΔVc, and the j-th coefficient to obtain the j-th current reference signal Vcpj, it is possible to ensure that when the multiphase switching power supply 40 is in a stable state, the average inductor current of the j-th phase power conversion circuit is consistent with the product of the average inductor current of the first phase power conversion circuit and the j-th coefficient. Furthermore, by setting the j-th coefficient according to the heat dissipation conditions of the first phase power conversion circuit and the j-th phase power conversion circuit, thermal balance of each starting phase power conversion circuit can be achieved. For example, if the heat dissipation conditions of the first phase power conversion circuit are better than those of the j-th phase power conversion circuit, the j-th coefficient can be set to be less than 1; if the heat dissipation conditions of the j-th phase power conversion circuit are better than those of the first phase power conversion circuit, the j-th coefficient can be set to be greater than 1.

[0069] Specifically, in Figure 7 In the illustrated embodiment three, the superposition unit 452 is further configured to obtain a j-th compensation signal Vcj based on a first compensation signal Vc1 and a j-th coefficient kj, and to superimpose the j-th compensation signal Vcj and a first adjustment voltage ΔVc to obtain a j-th current reference signal Vcpj, wherein the j-th compensation signal Vcj is equal to the product of the first compensation signal Vcj and the j-th coefficient kj, and j is any integer greater than or equal to 2 and less than or equal to N. For example, refer to... Figure 7The superposition unit 452 includes second voltage conversion units 4522 to Nth voltage conversion units 452N, a first adder circuit A1, and second adder circuits A2 to Nth adder circuits AN. The j-th voltage conversion unit 452j is connected to a first compensation signal Vc1 and configured to perform voltage conversion on the first compensation signal according to the j-th coefficient kj to obtain a j-th compensation signal Vcj. The first input terminal of the first adder circuit A1 receives the first compensation signal Vc1, the second input terminal receives a first adjustment voltage ΔVc, and the output terminal outputs a first current reference signal Vcp1. The first input terminal of the j-th adder circuit Aj receives the j-th compensation signal Vcj, the second input terminal receives the first adjustment voltage ΔVc, and the output terminal outputs the j-th current reference signal Vcpj. It is easily understood that in... Figure 7 In the third embodiment shown, the superposition unit 452 uses the adjustment signal as the first adjustment voltage ΔVc, and the superposition is achieved using the addition circuits A1 to AN. However, this application is not limited to this; for example, other methods may also be used. Figure 5 This is achieved as shown.

[0070] In conclusion, in such cases... Figure 6 , Figure 7 In the illustrated embodiment, since the first compensation signal Vc1 can change rapidly with the change in the number of starting phases Nact when the number of starting phases Nact changes, and the current reference signal of each starting phase power conversion circuit is obtained based on the first compensation signal Vc1, the inductor current of each starting phase power conversion circuit can be quickly adjusted when the number of starting phases changes; the first adjustment voltage can be dynamically adjusted according to the first compensation signal and the first signal to achieve consistency between the first compensation signal and the first signal in a stable state; the circuit structure is simple, the control is convenient, and it does not affect the system stability; when the j-th coefficient is set according to the heat dissipation conditions of each phase, the thermal balance of each starting phase power conversion circuit can be achieved, thus making it applicable to occasions with thermal balance requirements; when the second coefficient k2 to the Nth coefficient kN are all equal to 1, the average inductor current of each starting phase can be equal, thus making it applicable to occasions with current sharing requirements.

[0071] This invention also discloses a control method for a multiphase switching power supply, referencing... Figure 9 This control method can be applied to the above-mentioned multiphase switching power supply 30 / 40, and specifically includes the following steps:

[0072] In step S1, the output feedback signal of the multiphase switching power supply is amplified with a preset reference voltage to obtain the original compensation signal.

[0073] In step S2, a first compensation signal is obtained based on the original compensation signal and the first coefficient, wherein the first coefficient represents the ratio information of N and Nact, Nact is the number of phases of the power conversion circuit started by the multiphase switching power supply, and Nact is a positive integer less than or equal to N.

[0074] In this embodiment of the invention, the first compensation signal is equal to the product of the original compensation signal and the first coefficient.

[0075] In step S3, the current reference signal of each phase power conversion circuit is obtained according to the first compensation signal and the first signal, and the current reference signal of each start-up phase power conversion circuit is obtained according to the current reference signal of each start-up phase power conversion circuit to control each start-up phase power conversion circuit to provide power output to the load, so that the first compensation signal and the first signal are consistent in the steady state. The first signal represents the average inductance current information of the first phase power conversion circuit in the N-phase power conversion circuit.

[0076] In this embodiment of the invention, step S3 further includes: obtaining a first adjustment voltage based on a first compensation signal and a first signal; and superimposing the first compensation signal and the first adjustment voltage to obtain a current reference signal corresponding to each phase power conversion circuit.

[0077] In this embodiment of the invention, when the first compensation signal is greater than the first signal, the first adjustment voltage increases; when the first compensation signal is less than the first signal, the first adjustment voltage decreases.

[0078] In some possible embodiments, the method for obtaining the current reference signal corresponding to each phase power conversion circuit includes: superimposing a first compensation signal and a first adjustment voltage to obtain a first current reference signal, and using the first current reference signal as the current reference signal for the corresponding N-phase power conversion circuit. In other possible embodiments, the method for obtaining the current reference signal corresponding to each phase power conversion circuit includes: superimposing a first compensation signal and a first adjustment voltage to obtain a first current reference signal, and using the first current reference signal as the current reference signal for the corresponding first-phase power conversion circuit; and superimposing based on the first compensation signal, the first adjustment voltage, and a j-th coefficient to obtain a j-th current reference signal, and using the j-th current reference signal as the current reference signal for the corresponding j-th phase power conversion circuit, wherein the j-th coefficient characterizes the ratio information of the average inductor current target value of the j-th phase power conversion circuit to the average inductor current of the first-phase power conversion circuit, and j is any integer greater than or equal to 2 and less than or equal to N.

[0079] In this embodiment of the invention, step S3 further includes: obtaining a control signal for each startup phase power conversion circuit based on the current reference signal of each startup phase power conversion circuit, so as to control each startup phase power conversion circuit to provide power output to the load. For example, the method for obtaining the control signal for each startup phase power conversion circuit includes: generating a peak current reference signal and / or a valley current reference signal for the corresponding phase power conversion circuit based on the current reference signal of each startup phase power conversion circuit, and obtaining the control signal for the corresponding phase power conversion circuit based on the peak current reference signal and / or the valley current reference signal of the corresponding phase power conversion circuit, and the inductor current sampling signal of the corresponding phase power conversion circuit.

[0080] In practice, the specific implementation of each step in the above control method can be found in the aforementioned embodiments of the multiphase switching power supply 30 / 40, and will not be repeated here.

[0081] In summary, the embodiments of the present invention obtain a first compensation signal based on the original compensation signal and a first coefficient, obtain a current reference signal for each phase power conversion circuit based on the first compensation signal and a first signal, and control each start-up phase power conversion circuit to provide power output to the load based on the current reference signal for each start-up phase power conversion circuit, so that the first compensation signal is consistent with the first signal in a stable state, and can quickly adjust the inductor current of each start-up phase power conversion circuit when the number of start-up phases changes. Furthermore, embodiments one and two of the present invention can achieve consistent average inductor current for each start-up phase, and can be applied to applications with current sharing requirements. Embodiment three of the present invention obtains a current reference signal for the corresponding j-th phase power conversion circuit based on the first compensation signal, the first signal, and the j-th coefficient. When the j-th coefficient is set according to heat dissipation conditions, thermal balance of each start-up phase power conversion circuit can be achieved, and it can be applied to applications with thermal balance requirements; when all j-th coefficients are set to 1, the average inductor current of each start-up phase is equal, and therefore it can also be applied to applications with current sharing requirements.

[0082] The embodiments described above do not constitute a limitation on the scope of protection of this technical solution. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the above embodiments should be included within the scope of protection of this technical solution.

Claims

1. A control circuit for a multiphase switching power supply, the multiphase switching power supply comprising an N-phase power conversion circuit, where N is the number of phases of the power conversion circuit configured in the multiphase switching power supply, and N is an integer greater than 1, characterized in that, The control circuit is configured to obtain a first compensation signal based on the original compensation signal and a first coefficient, obtain a current reference signal for each phase power conversion circuit based on the first compensation signal and a first signal, and control each start-up phase power conversion circuit to provide power output to the load based on the current reference signal for each start-up phase power conversion circuit, so that the first compensation signal is consistent with the first signal in a stable state. The original compensation signal is obtained by amplifying the error between the output feedback signal of the multiphase switching power supply and a preset reference voltage. The first coefficient represents the ratio information of N and Nact, where Nact is the number of phases of the power conversion circuit started by the multiphase switching power supply and Nact is a positive integer less than or equal to N. The first signal represents the average inductor current information of the first phase power conversion circuit in the N-phase power conversion circuit.

2. The control circuit according to claim 1, characterized in that, The control circuit includes: A first voltage conversion unit receives the original compensation signal and is configured to perform voltage conversion on the original compensation signal according to the first coefficient to obtain the first compensation signal. The current reference signal generation module receives the first compensation signal and the first signal, and is configured to obtain a first adjustment voltage based on the first compensation signal and the first signal, and to superimpose the first compensation signal and the first adjustment voltage to obtain a current reference signal corresponding to each phase power conversion circuit. The control module is configured to obtain control signals for each startup phase power conversion circuit based on the current reference signal of each startup phase power conversion circuit, so as to control each startup phase power conversion circuit to provide power output to the load.

3. The control circuit according to claim 1 or 2, characterized in that, The first compensation signal is equal to the product of the original compensation signal and the first coefficient.

4. The control circuit according to claim 1 or 2, characterized in that, When the first compensation signal is greater than the first signal, the first adjustment voltage increases; When the first compensation signal is less than the first signal, the first adjustment voltage decreases.

5. The control circuit according to claim 2, characterized in that, The current reference signal generation module includes: The first adjustment unit receives the first compensation signal and the first signal, and outputs an adjustment signal according to the first compensation signal and the first signal. The superposition unit is configured to obtain the first adjustment voltage based on the adjustment signal, and to superimpose the first compensation signal and the first adjustment voltage to obtain the current reference signal corresponding to each phase power conversion circuit.

6. The control circuit according to claim 5, characterized in that, The superposition unit is configured to superimpose the first compensation signal and the first adjustment voltage to obtain a first current reference signal, and use the first current reference signal as the current reference signal corresponding to the N-phase power conversion circuit.

7. The control circuit according to claim 5, characterized in that, The superposition unit is configured to superimpose the first compensation signal and the first adjustment voltage to obtain a first current reference signal, and use the first current reference signal as the current reference signal corresponding to the first phase power conversion circuit. as well as, The j-th current reference signal is obtained by superimposing the first compensation signal, the first adjustment voltage, and the j-th coefficient, and is used as the current reference signal for the corresponding j-th phase power conversion circuit. Wherein, the j-th coefficient represents the ratio of the target value of the average inductor current of the j-th phase power conversion circuit to the average inductor current of the 1-th phase power conversion circuit, and j is any integer greater than or equal to 2 and less than or equal to N.

8. The control circuit according to claim 7, characterized in that, When the multiphase switching power supply is in a stable state, the average inductor current of the j-th phase power conversion circuit is the same as the product of the average inductor current of the 1-th phase power conversion circuit and the j-th coefficient.

9. The control circuit according to claim 7, characterized in that, The superposition unit is further configured to obtain a j-th compensation signal based on the first compensation signal and the j-th coefficient, and to superimpose the j-th compensation signal and the first adjustment voltage to obtain the j-th current reference signal. Wherein, the j-th compensation signal is equal to the product of the first compensation signal and the j-th coefficient.

10. The control circuit according to claim 9, characterized in that, The superposition unit includes the second voltage conversion unit to the Nth voltage conversion unit. The j-th voltage conversion unit receives the first compensation signal and is configured to perform voltage conversion on the first compensation signal according to the j-th coefficient to obtain the j-th compensation signal.

11. The control circuit according to any one of claims 7-10, characterized in that, The j-th coefficient is set according to the heat dissipation conditions of the first phase power conversion circuit and the j-th phase power conversion circuit to achieve thermal balance of each starting phase power conversion circuit.

12. A control method for a multiphase switching power supply, wherein the multiphase switching power supply includes an N-phase power conversion circuit, where N is the number of phases of the power conversion circuit configured in the multiphase switching power supply, and N is an integer greater than 1, characterized in that... The control method includes: The output feedback signal of the multiphase switching power supply is amplified with respect to a preset reference voltage to obtain the original compensation signal. The first compensation signal is obtained based on the original compensation signal and the first coefficient; Based on the first compensation signal and the first signal, the current reference signal for each phase power conversion circuit is obtained, and each start-up phase power conversion circuit is controlled to provide power output to the load based on the current reference signal for each start-up phase power conversion circuit, so that the first compensation signal and the first signal are consistent under steady state. Wherein, the first coefficient represents the ratio information of N and Nact, Nact is the number of phases of the power conversion circuit started by the multiphase switching power supply, Nact is a positive integer less than or equal to N, and the first signal represents the average inductor current information of the first phase power conversion circuit in the N-phase power conversion circuit.

13. The control method according to claim 12, characterized in that, The method for obtaining the current reference signal corresponding to each phase power conversion circuit based on the first compensation signal and the first signal includes: A first adjustment voltage is obtained based on the first compensation signal and the first signal; The current reference signal for each phase power conversion circuit is obtained by superimposing the first compensation signal and the first adjustment voltage.

14. The control method according to claim 13, characterized in that, The method for obtaining a current reference signal corresponding to each phase power conversion circuit by superimposing the first compensation signal and the first adjustment voltage includes: The first compensation signal and the first adjustment voltage are superimposed to obtain a first current reference signal, and the first current reference signal is used as the current reference signal corresponding to the N-phase power conversion circuit.

15. The control method according to claim 13, characterized in that, The method for obtaining a current reference signal corresponding to each phase power conversion circuit by superimposing the first compensation signal and the first adjustment voltage includes: The first compensation signal and the first adjustment voltage are superimposed to obtain a first current reference signal, and the first current reference signal is used as the current reference signal corresponding to the first phase power conversion circuit; and, The j-th current reference signal is obtained by superimposing the first compensation signal, the first adjustment voltage, and the j-th coefficient, and is used as the current reference signal for the corresponding j-th phase power conversion circuit. Wherein, the j-th coefficient represents the ratio of the target value of the average inductor current of the j-th phase power conversion circuit to the average inductor current of the 1-th phase power conversion circuit, and j is any integer greater than or equal to 2 and less than or equal to N.

16. A multiphase switching power supply, characterized in that, It includes an N-phase power conversion circuit and a control circuit as described in any one of claims 1-11, where N is the number of phases of the power conversion circuit configured in the multi-phase switching power supply, and N is an integer greater than 1.

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