Control circuit, control method of multiphase power supply and multiphase power supply

Abstract

The application discloses a control circuit and a control method of a multi-phase power supply and the control circuit comprises: a plurality of error signal generation modules, each of which is configured to receive a feedback signal representing an expected average value of each-phase output current and an inductor current signal of a corresponding phase power conversion circuit, and obtain an error signal representing an average value of peak and valley values of the feedback signal and the inductor current signal according to a comparison result of the inductor current signal and the feedback signal in each switching cycle; and a plurality of control units, each of which is configured to obtain a control signal of the corresponding phase power conversion circuit according to the feedback signal and the error signal of the corresponding phase power conversion circuit, so as to control the average values of output currents of each phase power conversion circuit to be equal. The application can realize current balancing among channels of the multi-phase power supply, and has faster processing speed and higher efficiency.

Description

Technical Field

[0001] This invention relates to the field of power converter technology, specifically to a control circuit, control method, and multiphase power supply for a multiphase power supply. Background Technology

[0002] Modern electronic components, such as central processing units (CPUs) and memory, are experiencing progressively lower driving voltages, which reduces their tolerance for voltage ripple. However, the power consumption of these components has not decreased at the same rate, resulting in an increase in the current required for operation. This higher current, in turn, leads to greater voltage ripple. To address this issue, multiphase converter architectures have been developed, distributing the current across multiple converter circuits. Compared to single-phase converter architectures, multiphase converter architectures not only excel in eliminating voltage ripple but also offer superior advantages in dynamic response, output ripple current elimination, and heat dissipation.

[0003] However, in multiphase power supplies, the inductance of each channel is inevitably mismatched (the actual inductance value of each channel differs from the ideal value), affecting the balancing effect of the inductor current across channels. The larger the inductance value, the greater the current it carries. Therefore, to ensure balanced inductor current across channels (where balanced means that the inductor current values ​​of each channel are as equal as possible), current balancing control is required when operating this type of multiphase converter.

[0004] Traditional high dynamic response switching converters primarily employ a multi-channel interleaved parallel structure with dual-loop control (current and voltage loops) to improve dynamic response speed, maintain voltage control accuracy, and reduce voltage and current ripple. Voltage-mode control is the most commonly used control method in voltage-mode output power converters, capable of eliminating steady-state error and maintaining high accuracy. However, it cannot react immediately to load disturbances, resulting in less than ideal dynamic response speed. Current-mode control can be divided into average current control, peak current control, and valley current control. Peak / valley control is a fixed-clock-on, peak-current-off control method. This method can improve the converter's response speed to input voltage and load current changes. However, controlling the inductor current through peak / valley control can cause differences in the average output current of each channel in a multi-phase power supply, failing to ensure current balance among the channels. Existing average current control methods often achieve current sharing among channels through filtering, resulting in complex circuit structures and poor control efficiency and accuracy.

[0005] Therefore, it is necessary to provide improved technical solutions to overcome the above-mentioned technical problems existing in the prior art. Summary of the Invention

[0006] To address the aforementioned technical problems, this invention provides a control circuit, control method, and multiphase power supply for a multiphase power supply, which can achieve current balancing among the channels of the multiphase power supply, and has a faster processing speed and higher efficiency.

[0007] According to a first aspect of this disclosure, a control circuit for a multiphase power supply is provided, the multiphase power supply including an N-phase power conversion circuit, where N is an integer greater than 1, the control circuit comprising:

[0008] Multiple error signal generation modules are provided, each corresponding to one of the N-phase power conversion circuits. Each error signal generation module is configured to receive a feedback signal representing the expected average output current of each phase power conversion circuit and the inductor current signal of the corresponding phase power conversion circuit, and to obtain an error signal representing the average value of the peak and valley values ​​of the feedback signal and the inductor current signal based on the comparison result of the inductor current signal and the feedback signal in each switching cycle.

[0009] Multiple control units are configured to correspond one-to-one with the N-phase power conversion circuit. Each control unit is configured to correct the error signal of the corresponding phase power conversion circuit based on the feedback signal and the error signal of the corresponding phase power conversion circuit, and to obtain the control signal of the corresponding phase power conversion circuit based on the corrected feedback signal, so as to control the average value of the output current of each phase power conversion circuit to be equal.

[0010] Optionally, the error signal is an integral signal generated by integrating the difference between a first time signal representing the duration during which the inductor current signal is greater than the feedback signal and a second time signal representing the duration during which the inductor current signal is less than the feedback signal within each switching cycle.

[0011] Optionally, each error signal generation module includes:

[0012] The comparison unit receives the inductor current signal and the feedback signal respectively. The comparison unit is configured to compare the inductor current signal and the feedback signal, and generate the first time signal and the second time signal respectively based on the comparison result.

[0013] The time difference calculation unit is configured to perform a difference calculation on the first time signal and the second time signal, and output a first difference signal;

[0014] An integrator is configured to integrate the first difference signal and output the error signal.

[0015] Optionally, each phase power conversion circuit in the N-phase power conversion circuit includes a first switching device and a second switching device connected sequentially between the input voltage and the reference ground, and the inductor current signal received by each error signal generation module includes the current signal sampled during the conduction of the first switching device and / or the second switching device.

[0016] Optionally, the current reference signal includes a peak current reference signal or a valley current reference signal.

[0017] Optionally, each control unit includes an adder configured to perform an addition operation on the feedback signal and the error signal to generate the current reference signal.

[0018] Each control unit generates the control signal based on the inductor current of the power conversion circuit of the corresponding phase and the current reference signal to trigger a change in the on / off state of each switching device in the power conversion circuit of that phase.

[0019] Optionally, each control unit obtains a first control signal by comparing the inductor current of the power conversion circuit of the corresponding phase with the feedback signal, and obtains a second control signal by comparing the error signal of the power conversion circuit of the corresponding phase.

[0020] The first control signal and the second control signal serve as the control signals to trigger the switching on and off of each switching device in the phase power conversion circuit.

[0021] According to a second aspect of this disclosure, a multiphase power supply is provided, comprising:

[0022] An N-phase parallel coupled power conversion circuit, wherein each phase power conversion circuit has an input terminal coupled to the input voltage and an output terminal coupled to the load to provide power output, where N is an integer greater than 1;

[0023] A control circuit, coupled to the N-phase power conversion circuit, is used to obtain an error signal representing the average value of the peak and valley values ​​of the feedback signal and the inductor current signal of the corresponding phase power conversion circuit in each switching cycle, based on a comparison between the feedback signal and the inductor current signal of the corresponding phase power conversion circuit. The control circuit then obtains a control signal for each phase power conversion circuit in the N-phase power conversion circuit based on the error signal of the feedback signal and the corresponding phase power conversion circuit, so that the average value of the output current of each phase power conversion circuit is equal.

[0024] The feedback signal is used to characterize the expected average output current of each phase power conversion circuit.

[0025] Optionally, the multiphase power supply further includes:

[0026] Multiple drive units are configured to generate drive signals based on control signals generated by multiple control units in the control circuit, and send the drive signals to the control terminals of each switching device in the corresponding phase power conversion circuit.

[0027] According to a third aspect of this disclosure, a control method for a multiphase power supply is provided, the multiphase power supply including an N-phase power conversion circuit, where N is an integer greater than 1, the control method comprising:

[0028] Obtain a feedback signal that characterizes the expected average output current of each phase power conversion circuit;

[0029] In each switching cycle, an error signal is obtained based on the feedback signal and the inductor current signal of the corresponding phase power conversion circuit, which characterizes the average value of the peak and valley values ​​of the feedback signal and the inductor current signal.

[0030] Based on the feedback signal and the error signal of the corresponding phase power conversion circuit, a control signal for each phase power conversion circuit is obtained to control the average value of the output current of each phase power conversion circuit to be equal.

[0031] Optionally, the method for obtaining the error signal includes:

[0032] In each switching cycle, the inductor current signal is compared with the feedback signal, and a first time signal is generated when the inductor current signal is greater than the feedback signal, and a second time signal is generated when the inductor current signal is less than the feedback signal.

[0033] The difference between the first time signal and the second time signal is calculated.

[0034] The error signal is obtained by integrating the difference.

[0035] Optionally, obtaining the control signal for each phase power conversion circuit based on the feedback signal and the error signal of the corresponding phase power conversion circuit includes:

[0036] The feedback signal and the error signal are added together to generate a current reference signal for the corresponding phase power conversion circuit;

[0037] Based on the current reference signal, a peak current reference signal and / or a valley current reference signal are generated for the corresponding phase power conversion circuit;

[0038] The control signal is obtained based on the peak current reference signal and / or valley current reference signal of the corresponding phase power conversion circuit, as well as the inductor current.

[0039] Optionally, obtaining the control signal for each phase power conversion circuit based on the feedback signal and the error signal of the corresponding phase power conversion circuit includes:

[0040] The peak current reference signal and / or valley current reference signal of the corresponding phase power conversion circuit are generated based on the feedback signal.

[0041] A first control signal is obtained based on the peak current reference signal and / or valley current reference signal of the corresponding phase power conversion circuit, and the inductor current.

[0042] The second control signal is obtained based on the error signal of the power conversion circuit of the corresponding phase.

[0043] The first control signal and the second control signal serve as the control signals to trigger the switching on and off of each switching device in the phase power conversion circuit.

[0044] The beneficial effects of the present invention include at least the following:

[0045] This invention corrects the switching time of the corresponding phase power conversion circuit by calculating the error signal between the feedback signal representing the expected average output current of each phase power conversion circuit and the average peak and valley values ​​of the inductor current signal of the corresponding phase power conversion circuit. This ensures that each phase power conversion circuit can provide power output to the load with the same output current (average current), effectively eliminating differences in output current between phase power conversion circuits caused by variations in inductance values ​​within the N-phase power conversion circuits. This facilitates current balancing across the channels of a multi-phase power supply. Furthermore, this invention eliminates the need for filtering and averaging the output current of each phase power conversion circuit during current sharing, resulting in faster and more efficient current sharing processing and improved accuracy of current sharing control.

[0046] It should be noted that the above general description and the following detailed description are exemplary and explanatory only, and do not limit the present invention. Attached Figure Description

[0047] Figure 1 This diagram shows a schematic of an existing multiphase power supply.

[0048] Figure 2 This diagram illustrates the structure of a multiphase power supply according to an embodiment of the present invention.

[0049] Figure 3 Show Figure 2 A schematic diagram of the error signal generation module corresponding to the first phase power conversion circuit in the middle;

[0050] Figure 4A schematic diagram of a first time signal and a second time signal provided according to an embodiment of the present invention is shown;

[0051] Figure 5 A flowchart illustrating a control method for a multiphase power supply according to an embodiment of the present invention is shown. Detailed Implementation

[0052] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Preferred embodiments of the invention are shown in the drawings. However, the invention can be implemented in various forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the invention.

[0053] It should be noted that, in this document, the switching device is a transistor operating in switching mode to provide a current path, including one selected from bipolar transistors or field-effect transistors. The first and second terminals of the switching device are respectively the high-potential terminal and the low-potential terminal on the current path, and the control terminal of the switching device is used to receive a drive signal to control the transistor's on and off states. Furthermore, in this application, the description of the on and off states of the power conversion circuit corresponds to the on and off states of the main switching device in the power conversion circuit that receives the input voltage. For example, turning on the power conversion circuit corresponds to turning on the main switching device in the power conversion circuit to connect the energy storage element in the circuit to the input for charging and energy storage, and to starting to provide power output to the load (i.e., generating a corresponding output voltage based on the input voltage); turning off the power conversion circuit corresponds to turning off the main switching device in the power conversion circuit to end the charging and energy storage state of the energy storage element in the circuit, and to stopping the power output to the load.

[0054] Figure 1 A schematic diagram of an existing multiphase power supply is shown. For example... Figure 1As shown, the multiphase power supply 100 includes: a multiphase power supply control circuit 110, N-phase power conversion circuits 101-10N (N is an integer greater than or equal to 1), and a feedback control circuit 120. Each phase power conversion circuit includes a driver, a first switching device T1 and a second switching device T2, and an inductor Lx. The first switching device T1 and the second switching device T2 are connected between the input voltage Vin and the reference ground. The first end of the inductor Lx is connected to the intermediate node between the first switching device T1 and the second switching device T2, and the second end is connected to the first end of the output capacitor Cout. The second end of the output capacitor Cout is grounded. The driver in each phase power conversion circuit 101-10N receives a control signal, i.e., a pulse width modulation signal PWM1-PWMN, provided by the multiphase power supply controller 110, and controls the corresponding switching device transistor to turn on and off according to the received control signal, charging the energy storage element of this phase for a corresponding duration to generate the output voltage Vo1-VoN of this phase. The output voltages Vo1-VoN are combined into a single output voltage Vout, and the load is driven based on the output capacitor Cout. The multiphase power supply control circuit 110 includes multiple control units 111-11N. Each control unit uses the feedback signal Vc1 output by the feedback control circuit 120 as its own current reference signal, and then controls the on / off of each switching device T1 and T2 based on the comparison results of its own inductor current and the current reference signal Vc1.

[0055] exist Figure 1 In the multiphase power supply shown, the inductance values ​​of each phase typically differ significantly in practical applications. This difference causes the inductors to respond differently to the same current, resulting in different output currents for each phase's power conversion circuit. Specifically, the output current of each phase's power conversion circuit differs from the total output current I of the multiphase power supply 100. SUM The average value (I) in the N-phase power conversion circuit SUM The difference between / N makes it impossible to ensure current balance between the channels (corresponding to the power conversion circuits of each phase) of the multiphase power supply.

[0056] To address the aforementioned problems, this invention improves the control circuit of a multiphase power supply and proposes a control method capable of achieving rapid current equalization. By calculating the error signal between the feedback signal representing the expected average output current of each phase power conversion circuit and the average peak and valley values ​​of the inductor current signal of the corresponding phase power conversion circuit, the switching time of the corresponding phase power conversion circuit is corrected. This helps to eliminate the differences in output current between the phase power conversion circuits caused by the differences in inductance values ​​in the N-phase power conversion circuit, thereby enabling rapid and accurate current equalization.

[0057] like Figure 2 As shown, Figure 2A schematic diagram of the circuit structure of a multiphase power supply according to an embodiment of the present invention is shown. The multiphase power supply of the present invention includes a control circuit for the multiphase power supply and an N-phase power conversion circuit, where N is a positive integer greater than 1. The control circuit of the multiphase power supply is used to control the conduction sequence and charging time of the N-phase power conversion circuit to jointly output an output voltage Vout.

[0058] Specifically, refer to Figure 2 The multiphase power supply 200 includes a control circuit (hereinafter referred to as the control circuit) 210, an N-phase parallel coupled power conversion circuit 201-20N, and a feedback control circuit 220.

[0059] Each phase of the N-phase power conversion circuit 201-20N has an input terminal coupled to the input voltage and an output terminal coupled to the load to provide power output.

[0060] It should be noted that, although Figure 2 The power conversion circuit shown can be referenced. Figure 1 The structure of the power conversion circuit 101 in the invention is explained. Although the power conversion circuit is described as having a buck topology, the technical solution of the present invention can be adopted for any type of layout design, such as boost, flyback, buck-boost, Cuk, Sepic, and Zeta.

[0061] Control circuit 210 is coupled to N-phase power conversion circuits 201-20N. Control circuit 210 is used in each switching cycle to respond to a feedback signal (denoted as Vc0, where Vc0 is proportional to I) characterizing the expected average output current of each phase power conversion circuit. SUM / N, where I SUM The total output current of the multiphase power supply 200 is N, which actually represents the number of phases of the power conversion circuit currently operating in the multiphase power supply 200, and the inductor current signal of the corresponding phase power conversion circuit (denoted as V). RS The comparison results yield the feedback signal Vc0 and the inductor current signal Vc0, which characterize the corresponding phase power conversion circuit. RS The error signal (denoted as ΔVc) of the average of the peak and valley values ​​is obtained, and the control signal for each phase power conversion circuit in the N-phase power conversion circuit is obtained based on the feedback signal Vc0 and the error signal ΔVc of the corresponding phase power conversion circuit, so that the average value of the output current of each phase power conversion circuit is equal. Among them, the inductor current signal V RS The average of the peak and trough values ​​is equal to the inductor current signal V. RS Half of the sum of the peak and valley values, in this embodiment, the inductor current signal V is used. RSThe average of the peak and valley values ​​represents the average inductor current during each switching cycle.

[0062] In this embodiment, the control circuit 210 further includes: a feedback control circuit 220, multiple error signal generation modules 2111-211N, and multiple control units 2121-212N. It should be noted that in this embodiment, the multiple error signal generation modules 2111-211N, the multiple control units 2121-212N, and the N-phase power conversion circuits 210-20N are in a one-to-one correspondence with each other.

[0063] The first input terminal of the feedback control circuit 220 is connected to the output terminals of the N-phase power conversion circuits 201-20N to receive the output feedback signal (denoted as FB) representing the output voltage Vout of the multiphase power supply 200. The second input terminal of the feedback control circuit 220 receives the reference voltage signal (denoted as Vref). The output terminal of the feedback control circuit 220 is connected to multiple error signal generation modules 2111-211N. The feedback control circuit 220 is configured to compare the output feedback signal FB of the multiphase power supply 200 with the reference voltage signal Vref to obtain a first compensation signal, and output the first compensation signal as the feedback signal Vc0 required by each phase power conversion circuit in the average current control mode to each error signal generation module.

[0064] In this embodiment, the feedback signal Vc0 is used to perform average current control on each phase power conversion circuit by utilizing the difference between the output feedback signal FB and the preset reference voltage signal Vref. This ensures that when the multiphase power supply 200 reaches a stable state, the feedback signal Vc0 can be used to characterize the expected average output current of each phase power conversion circuit. Furthermore, since each phase power conversion circuit operates based on the same feedback signal Vc0, the average output current of each phase power conversion circuit is the same when the multiphase power supply 200 reaches a stable state. For example, the output feedback signal FB can be obtained by dividing the output voltage Vout of the multiphase power supply 200 using a resistor voltage divider sampling unit. In some possible embodiments of the present invention, the feedback control circuit 220 specifically includes an error amplifier circuit and a compensation circuit. The first input terminal of the error amplifier circuit receives the reference voltage signal Vref, the second input terminal receives the output feedback FB, and the output terminal of the error amplifier circuit is connected to the compensation circuit, outputting a first compensation signal as the feedback signal Vc0.

[0065] Each of the multiple error signal generation modules 2111-211N is configured to receive the feedback signal Vc0 and the inductor current signal V of the corresponding phase power conversion circuit. RS And in each switching cycle, based on the inductor current signal V RSThe comparison result with the feedback signal Vc0 yields a characterization of the relationship between the feedback signal Vc0 and the inductor current signal V. RS The error signal ΔVc is the average of the peak and trough values. In this embodiment, the error signal ΔVc is, for example, the error signal representing the inductor current signal V during each switching cycle. RS The first time signal (denoted as TL1) with a duration greater than the feedback signal Vc0 and the inductor current signal V RS The integral signal is generated by integrating the difference between the second time signal (TH1) and the second time signal (which is shorter than the duration of the feedback signal Vc0).

[0066] In this embodiment, each of the plurality of error signal generation modules 2111-211N adopts the same circuit structure, the only difference being the signals they receive and / or output. Specifically, refer to Figure 3 In this paper, the circuit structure of each error signal generation module is described using only the error signal generation module 2111 corresponding to the first phase power conversion circuit 201 as an example. The error signal generation module 2111 further includes: a current acquisition unit 21111, a comparison unit 21112, a time difference calculation unit 21113, and an integrator 21114.

[0067] The current acquisition unit 21111 is configured to sample the current flowing through the target switching device during the conduction period of the target switching device in the corresponding phase power conversion circuit, so as to obtain the inductor current (denoted as i) that characterizes the phase. L1 An inductor current signal of magnitude (denoted as V) RS Optionally, the current acquisition unit 21111 can obtain the inductor current signal V by separately setting the sampling resistor at the target switch. RS Alternatively, the inductor current signal V can be obtained by sampling the inductor current in the power conversion circuit of that phase during the conduction period of the target switch. RS Furthermore, the inductor current signal V can be reconstructed through calculation based on parameters such as input voltage and output voltage, as well as specific formulas. RS This invention does not limit the scope of the invention. It should be noted that the following description will only use the target switching device as the lower switching device (i.e., the second switching device T2) in the corresponding phase power conversion circuit as an example. However, it should be understood that in other embodiments of this invention, the target switching device may also be the upper switching device (i.e., the first switching device T1) in the corresponding phase power conversion circuit, or it may simultaneously include the first switching device T1 and the second switching device T2 (in which case both the current information on the second switching device T2 during its conduction period and the current information on the first switching device T1 during its conduction period are detected to further improve control accuracy). This invention does not limit the scope of the invention.

[0068] Comparison unit 21112 receives the sampled inductor current signal V. RS And feedback signal Vc0, the comparison unit 21112 is configured to compare the inductor current signal Vc0. RS It is compared with the feedback signal Vc0, and based on the inductor current signal V RS The comparison result with the feedback signal Vc0 generates a first time signal TL1 and a second time signal TH1, respectively. In this embodiment, as... Figure 4 As shown, the comparison unit 21112 can compare the inductor current signal V. RS When the value is greater than the feedback signal Vc0, the first time signal TL1 is generated, and the inductor current signal Vc0 is also generated. RS When the current is less than the feedback signal Vc0, a second time signal TH1 is generated. For example, the comparator unit 21112 can generate a second time signal TH1 based on the inductor current signal Vc0. RS The comparison result with the feedback signal Vc0 generates high and low level signals, and the high level time period and the low level time period in the high and low level signals respectively characterize the first time signal TL1 and the second time signal TH1.

[0069] The time difference calculation unit 2113 is configured to perform a difference operation on the first time signal TL1 and the second time signal TH1, and output a first difference signal. It can be understood that this first difference signal can be used to characterize the difference between the peak value of the inductor current of each phase power conversion circuit and the feedback signal Vc0, and the difference between the valley value of the inductor current and the feedback signal Vc0 in one switching cycle. In other words, it can be used to characterize the average inductor current value of each phase power conversion circuit in one switching cycle and the average output current value I of the multi-phase power supply 200. SUM The difference information between / N. Simultaneously, when the first time signal TL1 and the second time signal TH1 are equal, i.e., when the first difference signal is zero, it indicates that the average inductor current of this phase power conversion circuit is equal to the average output current I of the multi-phase power supply 200. SUM / N. Optionally, the time difference calculation unit 2113 may be selected from circuit structures such as subtractor circuit, PWM comparator circuit, logic circuit, etc., as long as it can realize the difference calculation of the first time signal TL1 and the second time signal TH1. The present invention does not limit this.

[0070] Integrator 21114 is configured to integrate the first difference signal and output an error signal ΔVc.

[0071] Based on the working principle of the integrator, it is known that in a steady state, the input of integrator 21114 is zero. That is, when the multiphase power supply 200 reaches a steady state, for each phase power conversion circuit, TL1 equals TH1. This means that the average output current of that phase power conversion circuit (in this embodiment, the average output current within one cycle is set to be equal to half the sum of the maximum and minimum inductor currents within that cycle) equals the current value corresponding to the feedback signal Vc0. In other words, when the multiphase power supply 200 reaches a steady state, the average output current of each phase power conversion circuit is equal to the average value I of the total output current of the multiphase power supply 200. SUM / N, thus enabling rapid current sharing control of multi-phase power supplies.

[0072] Continue to refer to Figure 2 Each of the multiple control units 2121-212N is configured to obtain the control signal of the corresponding phase power conversion circuit based on the feedback signal Vc0 and the error signal ΔVc of the corresponding phase power conversion circuit, so as to control the average value of the output current of each phase power conversion circuit to be equal.

[0073] Optionally, in some possible embodiments of the present invention, each of the plurality of control units 2121-212N includes an adder 21211, as shown in the reference. Figure 3 The adder 21211 is configured to perform an addition operation on the feedback signal Vc0 and the error signal ΔVc to generate a current reference signal Vc1. Simultaneously, each control unit is also configured to generate a corresponding control signal based on the inductor current of the corresponding phase's power conversion circuit and the current reference signal to trigger changes in the on / off state of each switching device in that phase's power conversion circuit, so that the average value of the output current of each phase's power conversion circuit is equal, thereby achieving current balancing of the multi-phase power supply 200.

[0074] In this embodiment, the current reference signal Vc1, after processing, can be converted into a peak current reference signal and / or a valley current reference signal that controls the peak and / or valley values ​​of the inductor current in the corresponding phase power conversion circuit. For example, taking the Mth phase control unit 212M in the N-phase control units 2121-212N as an example, it can be configured to generate an Mth peak current reference signal and / or an Mth valley current reference signal based on the current reference signal VcM, and obtain an Mth control signal based on the Mth peak current reference signal and / or the Mth valley current reference signal, and the Mth inductor current sampling signal, to trigger the on / off control of each switching device in the Mth phase power conversion circuit. Here, M is any integer from 1 to N, and the Mth inductor current sampling signal characterizes the magnitude of the inductor current in the Mth phase power conversion circuit 20M.

[0075] In some other possible embodiments of the present invention, each of the multiple control units 2121-212N obtains a first control signal by comparing the inductor current of the corresponding phase power conversion circuit with the feedback signal Vc0, and obtains a second control signal by comparing the error signal ΔVc of the corresponding phase power conversion circuit. Furthermore, the first and second control signals can be used together as control signals for the corresponding phase power conversion circuit to trigger changes in the on / off states of each switching device in that phase power conversion circuit, so that the average value of the output current of each phase power conversion circuit is equal, thereby achieving current balancing of the multi-phase power supply 200. It should be noted that the second control signal, for example, is a time adjustment signal generated using the error signal ΔVc, corresponding to the time of the error signal ΔVc. This time adjustment signal adjusts the on / off time of each switching transistor in the corresponding phase power conversion circuit based on the control of the first control signal, thereby obtaining the corresponding output current.

[0076] Furthermore, the multiphase power supply 200 also includes multiple drive units and logic trigger units. These drive units are configured to generate drive signals based on control signals PWM1-PWMN generated by the multiple control units 2121-212N in the control circuit 210, and send the drive signals to the control terminals of each switching device in the corresponding phase power conversion circuit. Exemplarily, the multiple drive units are integrated into each phase power conversion circuit, or the multiple drive units are integrated into the control circuit 210, with each drive unit corresponding to a control unit.

[0077] The logic triggering unit is configured to control the on / off state of multiple control units 2121-212N and / or multiple drive units as needed.

[0078] Furthermore, the present invention also discloses a control method for a multiphase power supply, which can be applied to, for example... Figures 2 to 4 The multiphase power supply 200 shown is illustrated. Specifically, as... Figure 5 As shown, the control method includes performing the following steps:

[0079] In step S1, a feedback signal characterizing the expected average output current of each phase power conversion circuit is obtained.

[0080] In this embodiment, the method for obtaining the feedback signal includes: comparing the output feedback signal of the multiphase power supply with the reference voltage signal to obtain a first compensation signal, and using the first compensation signal as the feedback signal. Specifically, the specific implementation of step S1 can be understood by referring to the foregoing description of the feedback control circuit 220, and will not be repeated here.

[0081] In step S2, an error signal is obtained within each switching cycle based on the feedback signal and the inductor current signal of the corresponding phase power conversion circuit, which characterizes the average value of the peak and valley values ​​of the feedback signal and the inductor current signal.

[0082] In this embodiment, step S2 further includes: during the conduction period of the target switching device in the corresponding phase power conversion circuit, sampling the current flowing through the target switching device to obtain an inductor current signal; comparing the inductor current signal with a feedback signal, and generating a first time signal when the inductor current signal is greater than the feedback signal, and generating a second time signal when the inductor current signal is less than the feedback signal; calculating the difference between the first time signal and the second time signal; and integrating the difference to obtain an error signal. The target switching device is at least one of a first switching device and a second switching device. Specifically, the specific implementation of step S2 can be understood by referring to the aforementioned description of the error signal generation module, and will not be repeated here.

[0083] In step S3, control signals for each phase power conversion circuit are obtained based on the feedback signal and the error signal of the corresponding phase power conversion circuit, so as to control the average value of the output current of each phase power conversion circuit to be equal.

[0084] Optionally, in some possible embodiments of the present invention, step S3 further includes: performing an addition operation on the feedback signal and the error signal to generate a current reference signal for the corresponding phase power conversion circuit; 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; and obtaining a control signal based on the peak current reference signal and / or the valley current reference signal for the corresponding phase power conversion circuit, and the inductor current.

[0085] In some other possible embodiments of the present invention, step S3 further includes: generating a peak current reference signal and / or a valley current reference signal for the corresponding phase power conversion circuit based on the feedback signal; obtaining a first control signal based on the peak current reference signal and / or the valley current reference signal for the corresponding phase power conversion circuit, and the inductor current; obtaining a second control signal based on the error signal of the corresponding phase power conversion circuit, wherein the first control signal and the second control signal serve as control signals to trigger the switching on and off of each switching device in the phase power conversion circuit. Specifically, the specific implementation of step S3 can be understood by referring to the foregoing description of the multiple control units 2121-212N, and will not be repeated here.

[0086] In summary, the embodiments of the present invention correct the switching time of the corresponding phase power conversion circuit by calculating the error signal between the feedback signal representing the expected average output current of each phase power conversion circuit and the average peak and valley values ​​of the inductor current signal of the corresponding phase power conversion circuit. This enables each phase power conversion circuit to provide power output to the load with the same output current (average current), which helps to eliminate the differences in output current between the phase power conversion circuits caused by the differences in inductance values ​​in the N-phase power conversion circuits, and facilitates current balance among the channels of a multi-phase power supply. Furthermore, the technical solution of the present invention does not require filtering and averaging the output current of each phase power conversion circuit during the current sharing process, resulting in faster and more efficient current sharing processing of the output current of each phase, thus improving the accuracy of current sharing control.

[0087] Finally, it should be noted that the above embodiments are merely examples for clearly illustrating the present invention and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A control circuit for a multiphase power supply, wherein the multiphase power supply includes an N-phase power conversion circuit, where N is an integer greater than 1, wherein... The control circuit includes: Multiple error signal generation modules are provided, each corresponding to one of the N-phase power conversion circuits. Each error signal generation module is configured to receive a feedback signal representing the expected average value of the output current of each phase and the inductor current signal of the corresponding phase power conversion circuit, and to obtain an error signal representing the difference between the average value of the peak and valley values ​​of the feedback signal and the inductor current signal based on the comparison result of the inductor current signal and the feedback signal in each switching cycle. Multiple control units are configured to correspond one-to-one with the N-phase power conversion circuit. Each control unit is configured to obtain the control signal of the corresponding phase power conversion circuit based on the feedback signal and the error signal of the corresponding phase power conversion circuit, so as to control the average value of the output current of each phase power conversion circuit to be equal. The error signal is an integral signal generated by integrating the difference between a first time signal in which the inductor current signal is greater than the feedback signal and a second time signal in which the inductor current signal is less than the feedback signal within each switching cycle.

2. The control circuit according to claim 1, wherein, Each error signal generation module includes: The comparison unit receives the inductor current signal and the feedback signal respectively. The comparison unit is configured to compare the inductor current signal and the feedback signal, and generate the first time signal and the second time signal respectively based on the comparison result. The time difference calculation unit is configured to perform a difference calculation on the first time signal and the second time signal, and output a first difference signal; An integrator is configured to integrate the first difference signal and output the error signal.

3. The control circuit according to claim 1, wherein, Each phase of the N-phase power conversion circuit includes a first switching device and a second switching device connected sequentially between the input voltage and the reference ground. The inductor current signal received by each error signal generation module includes the current signal during the conduction of the first switching device and / or the second switching device.

4. The control circuit according to claim 1, wherein, Each control unit includes an adder configured to perform an addition operation on the feedback signal and the error signal to generate a current reference signal. Each control unit generates the control signal based on the inductor current of the power conversion circuit of the corresponding phase and the current reference signal to trigger a change in the on / off state of each switching device in the power conversion circuit of that phase.

5. The control circuit according to claim 1, wherein, Each control unit obtains a first control signal by comparing the inductor current of the corresponding phase's power conversion circuit with the feedback signal, and obtains a second control signal based on the error signal of the corresponding phase's power conversion circuit. The first control signal and the second control signal serve as the control signals to trigger the switching on and off of each switching device in the phase power conversion circuit.

6. A multiphase power supply, wherein, include: An N-phase parallel coupled power conversion circuit, wherein each phase power conversion circuit has an input terminal coupled to the input voltage and an output terminal coupled to the load to provide power output, where N is an integer greater than 1; The control circuit as described in any one of claims 1-5 is coupled to an N-phase power conversion circuit. The control circuit is configured to obtain, in each switching cycle, an error signal characterizing the difference between the average value of the peak and valley values ​​of the feedback signal and the average value of the inductor current signal, based on a comparison between the feedback signal and the inductor current signal of the corresponding phase power conversion circuit. Furthermore, the control circuit obtains a control signal for each phase power conversion circuit in the N-phase power conversion circuit based on the feedback signal and the error signal of the corresponding phase power conversion circuit, so that the average value of the output current of each phase power conversion circuit is equal. The feedback signal is used to characterize the expected average output current per phase.

7. The multiphase power supply according to claim 6, wherein, The multiphase power supply also includes: Multiple drive units are configured to generate drive signals based on control signals generated by multiple control units in the control circuit, and send the drive signals to the control terminals of each switching device in the corresponding phase power conversion circuit.

8. A control method for a multiphase power supply, wherein the multiphase power supply includes an N-phase power conversion circuit, where N is an integer greater than 1, wherein... The control method includes: Obtain a feedback signal that characterizes the expected average output current of each phase power conversion circuit; In each switching cycle, an error signal is obtained based on the feedback signal and the inductor current signal of the corresponding phase power conversion circuit, which represents the difference between the average value of the peak and valley values ​​of the feedback signal and the inductor current signal. Based on the feedback signal and the error signal of the corresponding phase power conversion circuit, a control signal for each phase power conversion circuit is obtained to control the average value of the output current of each phase power conversion circuit to be equal. The method for obtaining the error signal includes: In each switching cycle, the inductor current signal is compared with the feedback signal, and a first time signal is generated when the inductor current signal is greater than the feedback signal, and a second time signal is generated when the inductor current signal is less than the feedback signal. The difference between the first time signal and the second time signal is calculated. The error signal is obtained by integrating the difference.

9. The control method according to claim 8, wherein, The control signal for each phase power conversion circuit is obtained based on the feedback signal and the error signal of the corresponding phase power conversion circuit, including: The feedback signal and the error signal are added together to generate a current reference signal for the corresponding phase power conversion circuit; Based on the current reference signal, a peak current reference signal and / or a valley current reference signal are generated for the corresponding phase power conversion circuit; The control signal is obtained based on the peak current reference signal and / or valley current reference signal of the corresponding phase power conversion circuit, as well as the inductor current.

10. The control method according to claim 8, wherein, The control signal for each phase power conversion circuit is obtained based on the feedback signal and the error signal of the corresponding phase power conversion circuit, including: The peak current reference signal and / or valley current reference signal of the corresponding phase power conversion circuit are generated based on the feedback signal. The first control signal is obtained based on the peak current reference signal and / or valley current reference signal of the corresponding phase power conversion circuit, as well as the inductor current. The second control signal is obtained based on the error signal of the power conversion circuit of the corresponding phase. The first control signal and the second control signal serve as the control signals to trigger the switching on and off of each switching device in the phase power conversion circuit.

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