Power conversion circuit of multi-phase power supply, multi-phase power supply and control method thereof

Abstract

The present application discloses a power conversion circuit of a multi-phase power supply and a multi-phase power supply and a control method thereof. The power conversion circuit includes a PWM signal generating circuit, a driving circuit and a power circuit, wherein the PWM signal generating circuit is used to receive a counting code and generate a pulse width modulation signal when the counting value represented by the counting code is equal to its own number information, so as to control the on and off of the switch tube in the power circuit. Therefore, the multi-phase power supply using the above power conversion circuit can use a single timing circuit to control the on time of each phase power conversion circuit, which is conducive to reducing the complexity and cost of the controller, and at the same time can reduce the circuit scale and cost of the multi-phase power supply, which is conducive to the realization of a multi-phase power supply with a higher number of phases.

Description

Technical Field

[0001] The present invention relates to the technical field of switching power supplies, and more specifically, to a power conversion circuit of a multi-phase power supply. Background Art

[0002] The exponential growth of the scale of Internet of Things (IoT) cloud services has driven significant progress in data centers, networks, and telecommunications equipment. At the same time, the continued increase in data and information has posed new challenges to the processing efficiency of servers in data centers. Therefore, how to efficiently power and dissipate heat for these devices while minimizing power consumption has become an important issue in the existing power supply technology field.

[0003] Multiphase power supply is a technology that connects multiple power conversion circuits in parallel and distributes the switching modulation process to different phases to achieve the adjustment and control of the power supply. The PWM (pulse width modulation) signals between phases in a multiphase power supply can be the same or staggered by a certain phase, so that the fluctuation frequency seen by the output and input is the product of the switching frequency in each phase and the number of phases, thereby reducing the need for filter capacitors and the current impact on the input, while speeding up the response to load changes.

[0004] Figure 1 FIG. 2 shows a schematic circuit diagram of a multi-phase power supply according to the prior art. Figure 1 As shown, the existing multi-phase power supply 100 is composed of a multi-phase power supply controller 110, a multi-phase power conversion circuit 101-104 ( Figure 1 4-phase multi-phase power supply is taken as an example) and a feedback control circuit 120. The power conversion circuit of each phase includes a driver, switch tubes T1 and T2, an inductor Lx and an output capacitor Cout. The switch tubes T1 and T2 are connected between the input voltage Vin and the ground. The first end of the inductor Lx is connected to the middle node of the switch tubes T1 and 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 drivers in each power conversion circuit 101-104 each receive the pulse width modulation signal PWM1-PWM4 provided by the multi-phase power supply controller 110, and control the conduction and shutdown of the corresponding transistor according to the received pulse width modulation signal, charge the output capacitor Cout of the current phase to generate the output voltage Vo1-Vo4 of the current phase, and the output voltage Vo1-Vo4 is combined into an output voltage Vout to drive the load.

[0005] The multi-phase power supply controller 110 includes a plurality of PWM controllers 111-114, each of which determines the working order of the multi-phase power conversion circuits 101-104 according to the feedback signal FB of the feedback control circuit 120, thereby providing pulse width modulation signals PWM1-PWM4. The existing multi-phase power supply controller requires the same number of PWM controllers as the number of power conversion circuits, which not only has the problems of complex controller structure, large circuit scale, and high circuit cost, but also has matching problems between the PWM controllers, thereby affecting the accuracy of current balance of each phase of the multi-phase power supply. Summary of the invention

[0006] In view of the above problems, the purpose of the present invention is to provide a power conversion circuit of a multi-phase power supply and a multi-phase power supply and a control method thereof, which can not only reduce the circuit scale and cost of the controller, but also improve the problem of circuit mismatch affecting the accuracy of current balance of each phase.

[0007] According to a first aspect of the present invention, a power conversion circuit of a multi-phase power supply is provided, the multi-phase power supply comprising N-phase power conversion circuits, N being a positive integer greater than 1, wherein the power conversion circuit comprises: a PWM signal generating circuit, receiving a counting code, and generating a pulse width modulation signal when the counting code satisfies a preset condition; a driving circuit, converting the pulse width modulation signal into a switch driving signal; and a power circuit, comprising at least one switch tube, the switch driving signal being used to control the on and off of the at least one switch tube, thereby providing an output voltage of this phase according to an input voltage, wherein satisfying the preset condition comprises that the count value represented by the counting code is equal to the number information of the power conversion circuit.

[0008] Optionally, the counting code includes a first counting code and a second counting code, and the PWM signal generating circuit is used to generate an on-signal when the first counting code meets the preset condition, and the on-signal is used to determine the on-time of the at least one switching tube; when the second counting code meets the preset condition, an off-signal is generated, and the off-signal is used to determine the off-time of the at least one switching tube, and the pulse width modulation signal is obtained according to the on-signal and the off-signal.

[0009] Optionally, the first counting code is generated in response to a first timing signal, and the first timing signal is used to characterize the sequential changes of the N-phase power conversion circuit of the multi-phase power supply. The second counting code is generated in response to a second timing signal, and the second timing signal is delayed by a preset time compared to the first timing signal.

[0010] Optionally, the first counting code and the second counting code change at each clock edge of the first timing signal and the second timing signal respectively, and cyclically output N counting values.

[0011] Optionally, the N count values ​​correspond one-to-one to the numbering information of the N-phase power conversion circuits.

[0012] Optionally, the second timing signal is generated in response to a phase difference between an on-signal and an off-signal of the power conversion circuit, a preset time offset, an error between an output voltage of the multi-phase power supply and an expected voltage, and / or an input voltage change of the multi-phase power supply.

[0013] According to a second aspect of the present invention, a multi-phase power supply is provided, comprising: N phases of the above-mentioned power conversion circuit, N being a positive integer greater than 1; and a multi-phase power supply controller, the multi-phase power supply controller being used to provide a counting code to the N-phase power conversion circuit, the counting code being used to control the corresponding power conversion circuit in the N-phase power conversion circuit to generate an output voltage of the same phase according to the input voltage, wherein the corresponding power conversion circuit includes a power conversion circuit whose numbering information is equal to the count value represented by the counting code.

[0014] Optionally, the counting code includes a first counting code and a second counting code, and the corresponding power conversion circuit is used to generate a turn-on signal according to the first counting code, and to generate a turn-off signal according to the second counting code, wherein the turn-on signal is used to determine the turn-on time of at least one switching tube in the corresponding power conversion circuit, and the turn-off signal is used to determine the turn-off time of at least one switching tube in the corresponding power conversion circuit.

[0015] Optionally, the multi-phase power supply controller includes: a conduction sequence control circuit for generating a first timing signal, the first timing signal being used to characterize the sequential change of the N-phase power conversion circuit; a first counter, configured to perform a counting operation in response to the first timing signal to generate the first counting code; a shutdown sequence control circuit for generating a second timing signal, the second timing signal being delayed by a preset time than the first timing signal; and a second counter, configured to perform a counting operation in response to the second timing signal to generate the second counting code.

[0016] Optionally, the first counting code and the second counting code change at each clock edge of the first timing signal and the second timing signal respectively, and cyclically output N counting values.

[0017] Optionally, the N count values ​​correspond one-to-one to the numbering information of the N-phase power conversion circuit.

[0018] Optionally, the conduction sequence control circuit is implemented by a phase sequence oscillator.

[0019] Optionally, the shutdown sequence control circuit is implemented by a phase-locked loop circuit.

[0020] Optionally, the shutdown sequence control circuit includes: a frequency detector and a phase detector, used to receive a turn-on signal and a turn-off signal of one of the N-phase power conversion circuits, and obtain a phase difference between the turn-on signal and the turn-off signal; a delay control module, configured to generate a voltage control signal based on the phase difference between the turn-on signal and the turn-off signal, a preset time offset, an error between the output voltage of the multi-phase power supply and the expected voltage, and / or an input voltage change of the multi-phase power supply; and a voltage-controlled oscillator, configured to generate the second timing signal based on the voltage control signal.

[0021] Optionally, the multi-phase power supply controller also includes: a cross-cycle control circuit, which receives the first counting code and the second counting code, and is used to provide a correction signal to the N-phase power conversion circuit according to the delay time between the first counting code and the second counting code, and the correction signal is used to avoid the delay time from advancing to the previous voltage cycle or lagging behind the next voltage cycle.

[0022] According to a third aspect of the present invention, a control method for a multi-phase power supply is provided, the multi-phase power supply comprising N-phase power conversion circuits as described in any one of claims 1 to 6, N being a positive integer greater than 1, wherein the control method comprises: generating a first timing signal, the first timing signal being used to characterize sequential changes of the N-phase power conversion circuits; performing a counting operation in response to the first timing signal to generate the first counting code; generating a second timing signal, the second timing signal being delayed by a preset time than the first timing signal; performing a counting operation in response to the first timing signal to generate the second counting code; and a corresponding power conversion circuit in the N-phase power conversion circuit generating an output voltage of the current phase according to an input voltage in response to the first counting code and the second counting code, wherein the corresponding power conversion circuit comprises a power conversion circuit whose numbering information is equal to the count value represented by the first counting code and the second counting code.

[0023] Optionally, the corresponding power conversion circuit generates an output voltage of the current phase according to the input voltage in response to the first counting code and the second counting code, including: the corresponding power conversion circuit generates a turn-on signal according to the first counting code, and generates a turn-off signal according to the second counting code, wherein the turn-on signal is used to determine the turn-on time of at least one switch tube in the corresponding power conversion circuit, and the turn-off signal is used to determine the turn-off time of at least one switch tube in the corresponding power conversion circuit.

[0024] Optionally, the first counting code and the second counting code change at each clock edge of the first timing signal and the second timing signal respectively, and cyclically output N counting values.

[0025] Optionally, the N count values ​​correspond one-to-one to the numbering information of the N-phase power conversion circuit.

[0026] Optionally, generating the second timing signal includes: generating the second timing signal in response to a phase difference between a turn-on signal and a turn-off signal of one of the N-phase power conversion circuits, a preset time offset, an error between the output voltage of the multi-phase power supply and an expected voltage, and / or an input voltage change of the multi-phase power supply.

[0027] Optionally, the control method also includes: providing a correction signal to the N-phase power conversion circuit according to the delay time between the first counting code and the second counting code, and the correction signal is used to avoid the delay time from advancing to the previous voltage cycle or lagging behind the next voltage cycle.

[0028] The multi-phase power supply of the present invention provides a power conversion circuit, which includes a PWM signal generating circuit, a driving circuit and a power circuit. The PWM signal generating circuit is used to receive a counting code and generate a pulse width modulation signal when the counting value represented by the counting code is equal to its own numbering information to control the conduction and shutdown of the switch tube in the power circuit. Therefore, the multi-phase power supply using the above-mentioned power conversion circuit can use a single timing circuit to control the conduction time of each phase power conversion circuit, which is beneficial to reduce the complexity and cost of the controller.

[0029] The multi-phase power supply of the present invention also provides a multi-phase power supply controller, which uses a combination of a phase sequence oscillator and a first counter to determine the turn-on time of each phase power conversion circuit, and uses a combination of a phase-locked loop circuit and a second counter to determine the turn-off time of each phase power conversion circuit, thereby saving a PWM controller corresponding to each phase power conversion circuit, reducing the complexity and cost of the circuit, and avoiding the problem of current balance accuracy caused by circuit mismatch. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The above and other objects, features and advantages of the present invention will become more apparent through the following description of the embodiments of the present invention with reference to the accompanying drawings, in which:

[0031] Figure 1 A schematic circuit diagram of a multi-phase power supply according to the prior art is shown;

[0032] Figure 2 A schematic circuit diagram of a multi-phase power supply according to an embodiment of the present invention is shown;

[0033] Figure 3 A schematic circuit diagram showing a shutdown sequence control circuit in a multi-phase power supply according to an embodiment of the present invention;

[0034] Figure 4 A schematic circuit diagram showing a power conversion circuit in a multi-phase power supply according to an embodiment of the present invention;

[0035] Figure 5 A schematic timing diagram showing the operation of a multi-phase power supply according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0036] Various embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. In each of the accompanying drawings, identical elements are represented by identical or similar reference numerals. For the sake of clarity, the various parts in the accompanying drawings are not drawn to scale. In addition, some well-known parts may not be shown.

[0037] It should be understood that in the following description, "circuit" refers to a conductive loop composed of at least one element or subcircuit through electrical connection or electromagnetic connection. When an element or circuit is said to be "connected to" another element or an element / circuit is said to be "connected between" two nodes, it can be directly coupled or connected to another element or there can be an intermediate element, and the connection between the elements can be physical, logical, or a combination thereof. Conversely, when an element is said to be "directly coupled to" or "directly connected to" another element, it means that there is no intermediate element between the two.

[0038] In the present application, a switch tube is a transistor that operates in a switch mode to provide a current path, including one selected from a bipolar transistor or a field effect transistor. The first end and the second end of the switch tube are respectively a high potential end and a low potential end on the current path, and the control end is used to receive a drive signal to control the on and off of the switch tube.

[0039] The present invention may be embodied in various forms, some examples of which will be described below.

[0040] Figure 2 A schematic circuit diagram of a multi-phase power supply according to an embodiment of the present invention is shown. The multi-phase power supply according to the embodiment of the present invention includes a multi-phase power supply controller and an N-phase power conversion circuit, where N is a positive integer greater than 1, and the multi-phase power supply controller is used to control the conduction sequence and conduction time of the N-phase power conversion circuit to jointly output an output voltage.

[0041] Specifically, Figure 2As shown, the multi-phase power supply 200 includes a multi-phase power supply controller 210 and 8-phase power conversion circuits 201-208, and the multi-phase power supply controller 210 is used to provide a counting code to the power conversion circuits 201-208, and the counting code is used to control the corresponding power conversion circuits in the power conversion circuits 201-208 to generate the output voltage of the current phase according to the input voltage, wherein the corresponding power conversion circuits include power conversion circuits whose number information is equal to the count value represented by the counting code. Further, in each voltage cycle of the multi-phase power supply, the multi-phase power supply controller 210 outputs 8 count values ​​according to the counting code, thereby turning on the power conversion circuits 201-208 in sequence, and the power conversion circuits 201-208 respectively generate the duty cycle of the current phase and the corresponding output voltage Vo1-Vo8 according to the input voltage when working, and the output voltages Vo1-Vo8 are combined into one output after the duty cycle is fine-tuned by the current balancing circuit, and the load is driven by the output voltage Vout.

[0042] Further, the multi-phase power supply controller 210 includes a conduction sequence control circuit 211, a first counter 212, a shutdown sequence control circuit 213 and a second counter 214. The conduction sequence control circuit 211 is implemented, for example, by a phase sequence oscillator, and is used to generate a first timing signal CK1, and the first timing signal CK1 is used to represent the sequential change of the power conversion circuits 201-208 in the multi-phase power supply 200. The first counter 212 is configured to perform a counting operation in response to the first timing signal CK1 to provide a first counting code CNT1 to the power conversion circuits 201-208, and the power conversion circuits 201-208 sequentially compare the count value represented by the first counting code CNT1 with their own numbering information (the numbering information is, for example, the numbering of the power conversion circuits 201-208 according to the conduction sequence of the power conversion circuits 201-208). When the count value represented by the first counting code CNT1 is equal to its own numbering information, the power conversion circuit generates a conduction signal according to the first counting code CNT1, and the conduction signal is used to determine the conduction moment of at least one switch tube in the power conversion circuit. The shutdown sequence control circuit 213 is used to generate a second timing signal CK2, which is synchronized with the first timing signal CK1 and delayed by a preset time compared with the first timing signal CK1. The second counter 214 is configured to perform a counting operation in response to the second timing signal CK2 to provide a second counting code CNT2 to the power conversion circuits 201-208, and the power conversion circuits 201-208 sequentially compare the count value represented by the second counting code CNT2 with their own number information. When the count value represented by the second counting code CNT2 is equal to its own number information, the power conversion circuit generates a shutdown signal according to the second counting code CNT2, and the shutdown signal is used to determine the shutdown moment of at least one switch tube in the power conversion circuit. Among them, the time difference between the on-signal and the off-signal is used to control the PWM time of each channel, thereby saving the PWM controller corresponding to each phase power conversion circuit. Therefore, the circuit scale and structure of the multi-phase power supply controller in the embodiment of the present invention are smaller, which can reduce the cost of the controller, improve the integration of the multi-phase power supply, and facilitate the realization of a multi-phase power supply with a higher number of phases (for example, 16 phases or 24 phases).

[0043] Furthermore, the shutdown sequence control circuit 213 collects the on-signal and the off-signal of one of the power conversion circuits 201-208, monitors the phase difference between the on-signal and the off-signal, and adds a preset time offset between the on-signal and the off-signal, thereby obtaining a second timing signal CK2 that is delayed by a preset time compared to the first timing signal CK1 (see subsequent embodiments).

[0044] Furthermore, the first counting code CNT1 and the second counting code CNT2 are implemented by a cyclic binary code such as Gray code. Gray code is a code that changes only one bit when adding 1. The following table 1 is a three-bit Gray code encoding format:

[0045] Table 1

[0046] Q2 Q1 Q0 M 0 0 0 0 0 0 1 1 0 1 1 3 0 1 0 2 1 1 0 6 1 1 1 7 1 0 1 5 1 0 0 4

[0047] Since only one bit changes between adjacent code elements when the Gray code changes, no erroneous intermediate states will occur, and it has great use value in the engineering field.

[0048] It should be noted that the present invention is not limited to this, and the multi-phase power supply of the embodiment of the present invention can also be applied to other types of binary cyclic codes, and those skilled in the art can make a choice according to the specific situation.

[0049] Furthermore, the first counting code CNT1 and the second counting code CNT2 change at each clock edge (for example, a rising edge or a falling edge) of the first timing signal CK1 and the second timing signal CK2, respectively, thereby cyclically outputting N counting values ​​corresponding one to one to the numbering information of the N-phase power conversion circuit, where N is a positive integer greater than 1 (N=8 in this embodiment).

[0050] Furthermore, the shutdown sequence control circuit 213 is implemented by a phase-locked loop circuit, for example. Figure 3, the shutdown sequence control circuit 213 includes a frequency detector 2131, a delay control module 2132 and a voltage controlled oscillator 2133. The frequency detector 2131 is used to receive the on signal Pon and the off signal Poff of one of the power conversion circuits 201-208, and obtain the phase difference between the on signal Pon and the off signal Poff. The delay control module 2132 is used to receive the phase difference, and add a preset time offset between the on signal Pon and the off signal Poff, so that the off signal Poff in the power conversion circuit appears later than the on signal Pon, and the size of the added time offset determines the delay time between the on signal Pon and the off signal Poff, that is, the PWM modulation of the power conversion circuit is realized. Further, the delay control module 2131 also includes a feedback input terminal and a feedforward input terminal, the feedback input terminal is used to receive the error amount Verr between the output voltage Vout of the multi-phase power supply and the expected voltage Vref, and the feedforward input terminal is used to detect the change of the input voltage Vin. The delay control module 2132 provides a voltage control signal Vc to the voltage controlled oscillator 2133 according to the above input signal, and the voltage controlled oscillator 2133 generates a second timing signal CK2 according to the voltage control signal Vc, so that the delay time generated by the delay control module 2132 can be inherited to the subsequent oscillation process, and the PWM modulation of the power conversion circuit of the subsequent phase can be realized. Among them, the feedforward and feedback input signals can quickly realize the PWM modulation of the power conversion circuit and complete the fast and stable control of the output voltage. The speed of the phase-locked loop is very slow, so the phase stability can be controlled to cancel the imbalance part of the error feedback.

[0051] According to the above description, the shutdown sequence control circuit 213 of the present invention can reflect the detected phase difference between the on-signal Pon and the off-signal Poff as well as the feedback input and the feedforward input to the delay time of the second timing signal CK2 relative to the first timing signal CK1, so as to achieve the purpose of adjusting the pulse width of the PWM signal of each power conversion circuit. For example, when the output voltage Vout is small, the shutdown sequence control circuit 213 increases the delay time of the second timing signal CK2 relative to the first timing signal CK1, and when the multi-phase power supply controller 210 wants to control the next power conversion circuit, the pulse width of the PWM signal of the next power conversion circuit can be increased to achieve fast and stable control of the output voltage. Since the on-time of the power conversion circuits of each phase is staggered, the present invention adopts a method of providing the information of the on-time required by the power conversion circuits of each phase by combining a phase sequence oscillator and a counter, which can avoid the problem of circuit mismatch when using multiple PWM controllers.

[0052] It should be noted that the implementation method of the voltage-controlled oscillator 2133 is a common technical means in the art and will not be described in detail here.

[0053] Continue to refer to Figure 2 Generally speaking, a practical voltage-controlled oscillator 2133 needs to ensure that the delay time generated by the delay control module 2132 will not advance to the previous voltage cycle or lag behind to the next voltage cycle. However, in the actual operation of the multi-phase power supply, this situation is still unavoidable. Therefore, in a preferred embodiment, the multi-phase power supply controller 210 also includes a cross-cycle control circuit 215. The cross-cycle control circuit 215 is used to receive the first counting code CNT1 and the second counting code CNT2, and generate a correction signal Corr according to the delay time between the first counting code CNT1 and the second counting code CNT2. The correction signal Corr can prevent the delay time from advancing to the previous voltage cycle or lagging behind to the next voltage cycle.

[0054] Figure 4 A schematic circuit diagram of a power conversion circuit in a multi-phase power supply according to an embodiment of the present invention is shown. The structures of multiple power conversion circuits in the multi-phase power supply are the same. Figure 4 The power conversion circuit 201 is used for illustration. Figure 4 As shown, the power conversion circuit 201 adopts Buck topology, including a PWM signal generating circuit 2011, a driving circuit 2012 and a power circuit. The power circuit includes switch tubes T1 and T2 connected in series between an input terminal and a ground terminal, an inductor Lx connected between an intermediate node of the switch tubes T1 and T2 and an output terminal, an output capacitor Cout connected between the output terminal and a ground terminal, an input terminal of the power conversion circuit 201 receives an input voltage Vin, and an output terminal provides an output voltage Vo1 of the current phase.

[0055] The PWM signal generating circuit 2011 receives the first counting code CNT1 and the second counting code CNT2, and compares the count values ​​represented by the first counting code CNT1 and the second counting code CNT2 with its own number information, and determines the on time and off time of the switch tubes T1 and T2 according to the comparison result. Further, the PWM signal generating circuit 2011 is used to generate an on signal and an off signal when the count values ​​represented by the first counting code CNT1 and the second counting code CNT2 are equal to its own number information, respectively. The on signal is used to determine the on time of the switch tube T1, and the off signal is used to determine the off time of the switch tube T1, and the pulse width modulation signal PWM is obtained according to the on signal and the off signal. The driving circuit 2012 is used to convert the pulse width modulation signal PWM into a switch driving signal to control the on and off of the switch tubes T1 and T2, so as to generate the output voltage Vo1 of this phase according to the input voltage Vin.

[0056] It can be understood that the multi-phase power supply of the embodiment of the present invention can also be used in power conversion circuits of other topologies, and the structure of the power circuit includes but is not limited to floating Buck power circuit, solid Buck power circuit, flyback power circuit, Buck-boost power circuit and Boost power circuit topologies.

[0057] Figure 5 FIG. 2 is a schematic timing diagram showing the operation of a multi-phase power supply according to an embodiment of the present invention. Figure 5 In the embodiment of the present invention, the delay time of the second timing signal CK2 relative to the first timing signal CK1 is t1, PWM0-PWM7 respectively represent the waveform diagrams of the pulse width modulation signals of the power conversion circuits 201-208, and the numbers in the brackets after PWM0-PWM7 respectively represent the Gray codes of the power conversion circuits 201-208. In the embodiment of the present invention, the first counting code CNT1 and the second counting code CNT2 use a 3-bit binary Gray code, and the first counting code CNT1 and the second counting code CNT2 change at the rising edge of the first timing signal CK1 and the second timing signal CK2 respectively, and output 2 within a voltage cycle T. 3 As shown in Table 1, the change order of the first counting code CNT1 and the second counting code CNT2 during the counting operation is 000->001->011b->010->110->111->101->100, and the corresponding pulse width modulation signal order is PWM0->PWM1->PWM2->PWM3->PWM4->PWM5->PWM6->PWM7.

[0058] like Figure 5 As shown, at the first rising edge of the first timing signal CK1, the first counting code CNT1 is 000, the power conversion circuit 201 works, the pulse width modulation signal PWM0 flips to a high level, at the first rising edge of the second timing signal CK2, the second counting code CNT2 is 000, and the pulse width modulation signal PWM0 flips from a high level to a low level; at the second rising edge of the first timing signal CK1, the first counting code CNT1 is 001, the power conversion circuit 202 starts to work, the pulse width modulation signal PWM1 flips to a high level, at the second rising edge of the second timing signal CK2, the second counting code CNT2 is 001, and the pulse width modulation signal PWM1 flips from a high level to a low level; at the third rising edge of the first timing signal CK1, the first counting code CNT1 is 011, the power conversion circuit 203 starts to work, the pulse width modulation signal PWM2 flips from a low level to a high level, at the third rising edge of the second timing signal CK2, the second counting code CNT2 is 011, and the pulse width modulation signal PWM2 flips from a high level to a low level, and so on.

[0059] It should be noted that the configuration of the Gray codes of the power conversion circuits 201 - 208 is not limited to this embodiment, and those skilled in the art may number the order of the power conversion circuits 201 - 208 according to specific circumstances.

[0060] It should be understood that although Figure 2 The present invention is explained by taking an 8-phase multi-phase power supply as an example, but the multi-phase power supply controller of the present invention can be applicable to power conversion circuits with any number of phases, and because the circuit scale and structure of the multi-phase power supply controller of the present invention are smaller, the multi-phase power supply of the present invention can be applicable to a higher number of phases (for example, 16 phases or 24 phases).

[0061] In summary, the multi-phase power supply of the present invention provides a power conversion circuit, which includes a PWM signal generating circuit, a driving circuit and a power circuit. The PWM signal generating circuit is used to receive a counting code and generate a pulse width modulation signal when the counting value represented by the counting code is equal to its own numbering information to control the on and off of the switch tube in the power circuit. Therefore, the multi-phase power supply using the above-mentioned power conversion circuit can use a single timing circuit to control the on time of each phase power conversion circuit, which is beneficial to reduce the complexity and cost of the controller.

[0062] The multi-phase power supply of the present invention also provides a multi-phase power supply controller, which uses a combination of a phase sequence oscillator and a first counter to determine the turn-on time of each phase power conversion circuit, and uses a combination of a phase-locked loop circuit and a second counter to determine the turn-off time of each phase power conversion circuit, thereby saving a PWM controller corresponding to each phase power conversion circuit, reducing the complexity and cost of the circuit, and avoiding the problem of current balance accuracy caused by circuit mismatch.

[0063] In the above description, the well-known structural elements and steps are not described in detail. However, it should be understood by those skilled in the art that the corresponding structural elements and steps can be realized by various technical means. In addition, in order to form the same structural elements, those skilled in the art can also design methods that are not completely the same as the methods described above. In addition, although each embodiment is described above respectively, this does not mean that the measures in each embodiment cannot be advantageously used in combination.

[0064] According to the embodiments of the present invention, as described above, these embodiments do not describe all the details in detail, nor do they limit the invention to specific embodiments. Obviously, many modifications and changes can be made based on the above description. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can make good use of the present invention and the modified use based on the present invention. The scope of protection of the present invention shall be based on the scope defined by the claims of the present invention.

Claims

1. A power conversion circuit of a multi-phase power supply, the multi-phase power supply comprising N-phase power conversion circuits, N being a positive integer greater than 1, wherein: The power conversion circuit comprises: A PWM signal generating circuit receives a counting code and generates a pulse width modulation signal when the counting code meets a preset condition; a driving circuit, converting the pulse width modulation signal into a switch driving signal; and The power circuit includes at least one switch tube, wherein the switch driving signal is used to control the on and off of the at least one switch tube, thereby providing an output voltage of the current phase according to the input voltage. Wherein, the satisfying of the preset condition includes that the count value represented by the count code is equal to the serial number information of the power conversion circuit, Wherein, the counting code includes a first counting code and a second counting code, the PWM signal generating circuit is used to generate a conduction signal when the first counting code meets the preset condition, the conduction signal is used to determine the conduction time of the at least one switch tube, and generate a shutdown signal when the second counting code meets the preset condition, the shutdown signal is used to determine the shutdown time of the at least one switch tube, and the pulse width modulation signal is obtained according to the conduction signal and the shutdown signal. The first counting code is generated in response to a first timing signal, and the first timing signal is used to characterize the sequential change of the N-phase power conversion circuit of the multi-phase power supply. The second counting code is generated in response to a second timing signal, the second timing signal is delayed by a preset time compared to the first timing signal, and the second timing signal is generated in response to a phase difference between an on-signal and an off-signal of the power conversion circuit, a preset time offset, an error between an output voltage of the multi-phase power supply and an expected voltage, and / or an input voltage change of the multi-phase power supply.

2. The power conversion circuit according to claim 1, wherein: The first counting code and the second counting code change at each clock edge of the first timing signal and the second timing signal respectively, and cyclically output N counting values.

3. The power conversion circuit according to claim 2, wherein: The N count values ​​correspond one-to-one to the numbering information of the N-phase power conversion circuits.

4. A multiphase power supply comprising: The N-phase power conversion circuit according to any one of claims 1 to 3, wherein N is a positive integer greater than 1; as well as A multi-phase power supply controller, the multi-phase power supply controller is used to provide a counting code to the N-phase power conversion circuit, the counting code is used to control the corresponding power conversion circuit in the N-phase power conversion circuit to generate an output voltage of the current phase according to the input voltage, The corresponding power conversion circuit includes a power conversion circuit whose serial number information is equal to the count value represented by the count code.

5. The multiphase power supply according to claim 4, wherein: The counting code includes a first counting code and a second counting code, and the corresponding power conversion circuit is used to generate a turn-on signal according to the first counting code and generate a turn-off signal according to the second counting code. The on-signal is used to determine the on-time of at least one switch tube in the corresponding power conversion circuit, and the off-signal is used to determine the off-time of at least one switch tube in the corresponding power conversion circuit.

6. The multiphase power supply according to claim 5, wherein: The multi-phase power supply controller comprises: A conduction sequence control circuit, used for generating a first timing signal, wherein the first timing signal is used for representing a sequential change of the N-phase power conversion circuit; a first counter configured to perform a counting operation in response to the first timing signal to generate the first counting code; A shutdown sequence control circuit, configured to generate a second timing signal, wherein the second timing signal is delayed by a preset time compared to the first timing signal; and The second counter is configured to perform a counting operation in response to the second timing signal to generate the second counting code.

7. The multiphase power supply according to claim 6, wherein: The first counting code and the second counting code change at each clock edge of the first timing signal and the second timing signal respectively, and cyclically output N counting values.

8. The multiphase power supply according to claim 7, wherein: The N count values ​​correspond one-to-one to the numbering information of the N-phase power conversion circuits.

9. The multiphase power supply according to claim 6, wherein: The conduction sequence control circuit is implemented by a phase sequence oscillator.

10. The multiphase power supply according to claim 6, wherein: The shutdown sequence control circuit is implemented by a phase-locked loop circuit.

11. The multiphase power supply according to claim 10, wherein: The shutdown sequence control circuit comprises: A frequency detector and a phase detector, for receiving a turn-on signal and a turn-off signal of one of the N-phase power conversion circuits, and obtaining a phase difference between the turn-on signal and the turn-off signal; a delay control module configured to generate a voltage control signal according to a phase difference between the on-signal and the off-signal, a preset time offset, an error between an output voltage of the multi-phase power supply and a desired voltage, and / or an input voltage variation of the multi-phase power supply; and The voltage-controlled oscillator is configured to generate the second timing signal according to the voltage control signal.

12. The multiphase power supply according to claim 6, wherein: The multi-phase power supply controller also includes: The cross-cycle control circuit receives the first counting code and the second counting code, and is used to provide a correction signal to the N-phase power conversion circuit according to the delay time between the first counting code and the second counting code, wherein the correction signal is used to prevent the delay time from advancing to the previous voltage cycle or lagging behind to the next voltage cycle.

13. A method for controlling a multi-phase power supply, the multi-phase power supply comprising N-phase power conversion circuits according to any one of claims 1 to 3, N being a positive integer greater than 1, wherein: The control method comprises: generating a first timing signal, wherein the first timing signal is used to characterize a sequential change of the N-phase power conversion circuit; performing a counting operation in response to the first timing signal to generate the first counting code; generating a second timing signal, wherein the second timing signal is delayed by a preset time compared with the first timing signal; performing a counting operation in response to the first timing signal to generate the second counting code; and The corresponding power conversion circuit in the N-phase power conversion circuit generates an output voltage of the current phase according to the input voltage in response to the first counting code and the second counting code. The corresponding power conversion circuit includes a power conversion circuit whose serial number information is equal to the count value represented by the first counting code and the second counting code. Wherein, generating the second timing signal comprises: The second timing signal is generated in response to the phase difference between the on signal and the off signal of one of the N-phase power conversion circuits, a preset time offset, an error between the output voltage of the multi-phase power supply and the expected voltage, and / or an input voltage change of the multi-phase power supply.

14. The control method according to claim 13, wherein: The corresponding power conversion circuit generates an output voltage of the current phase according to the input voltage in response to the first counting code and the second counting code, comprising: The corresponding power conversion circuit generates a turn-on signal according to the first counting code, and generates a turn-off signal according to the second counting code, The on-signal is used to determine the on-time of at least one switch tube in the corresponding power conversion circuit, and the off-signal is used to determine the off-time of at least one switch tube in the corresponding power conversion circuit.

15. The control method according to claim 13, wherein: The first counting code and the second counting code change at each clock edge of the first timing signal and the second timing signal respectively, and cyclically output N counting values.

16. The control method according to claim 15, wherein: The N count values ​​correspond one-to-one to the numbering information of the N-phase power conversion circuits.

17. The control method according to claim 13, further comprising: A correction signal is provided to the N-phase power conversion circuit according to the delay time between the first counting code and the second counting code, wherein the correction signal is used to prevent the delay time from being advanced to a previous voltage cycle or being delayed to a subsequent voltage cycle.

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