CN117280589A

CN117280589A - Multiphase voltage reduction circuit, filter circuit and electronic equipment

Info

Publication number: CN117280589A
Application number: CN202280006695.7A
Authority: CN
Inventors: 秦亚霄; 王宁; 李汝婷; 郭金娥; 张学
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2022-04-22
Filing date: 2022-04-22
Publication date: 2023-12-22
Also published as: WO2023201716A1

Abstract

A multiphase voltage reduction circuit, a filter circuit and electronic equipment relate to the technical field of power electronics and the technical field of power supplies. The multiphase voltage reduction circuit comprises a controller, an auxiliary inductance module and at least two-phase voltage reduction circuits. Each phase of step-down circuit comprises a switch circuit and a filter circuit; the input end of the switching circuit is connected with a power supply, and the output end of the switching circuit is connected with the input end of the filter circuit. The output end of the filter circuit is connected with the output end of the multiphase voltage reduction circuit. The controller controls the switching circuit. The filter circuit includes an output inductance and at least one output capacitance. The output inductor is coupled with the auxiliary inductor module through a coupling winding; when the load current of the multiphase voltage reduction circuit is larger than the preset current, the inductance value of the auxiliary inductance module is a first inductance value; when the load current of the multiphase voltage reduction circuit is smaller than or equal to the preset current, the inductance value of the auxiliary inductance module is a second inductance value, and the first inductance value is smaller than the second inductance value. The scheme can realize quick dynamic response and reduce the occupied area and the hardware cost.

Description

Multiphase voltage reduction circuit, filter circuit and electronic equipment

Technical Field

The application relates to the technical field of power electronics, in particular to a multiphase voltage reduction circuit, a filter circuit and electronic equipment.

Background

With the continuous evolution of chips, the area of the chips and the types of power supply required by the chips are more and more, the power consumption of the chips is more and more, and the available area reserved for a power supply on a single board for arranging the chips is smaller and less, so that the improvement of the power supply density of the power supply is critical. On the other hand, the clock frequency of the chip is continuously accelerated, the working voltage is reduced, the working current is continuously increased, and the working current can be rapidly adjusted in a large dynamic range.

To meet the above requirements, the voltage regulation module (Voltage Regulator Module, VRM) shown in fig. 1 is generally used as a power source to supply power to the chip. The VRM is a multi-phase Buck (Buck) circuit. Each phase voltage step-down circuit includes a switching circuit 01 and an LC filter circuit 02. The LC filter circuit 02 includes an inductance and a capacitance. The capacitor may be one or a plurality of capacitors connected in parallel. The output end of each LC filter circuit 02 is connected with the input end of a load 03, and the load 03 is various chips. The power supply simultaneously supplies power to the multiphase voltage reduction circuit. The controller of the VRM controls the switching tubes of the voltage reduction circuits of each phase to be conducted in a staggered manner by utilizing pulse width modulation (Pulse Width Modulation, PWM) signals, so that ripple of output current is reduced, and ripple of the output voltage is also reduced.

Below to output inductance L ₁ The one-phase voltage-reducing circuit is illustrated as L when the control Q1 is turned on and Q2 is turned off ₁ Energy storage, inductor current I _L1 Rising, when Q1 is controlled to be off and Q2 is controlled to be on, the inductorCurrent I _L1 Descending. When the load 03 is in transient loading, the inductor current is increased by prolonging the time that the Q1 is turned on and the Q2 is turned off, so that energy is provided for the load 03. At present, the step-down circuit of each phase generally selects an inductor with a larger inductance value, so that ripple current in the inductor is smaller when a load is steady, and further, the conduction loss and the switching loss of the switching tube are reduced. However, this will cause the inductor current to increase until the load 03 needs a slower current, i.e. a slower dynamic response speed, when the load 03 is subjected to transient loading, so that more capacitors need to be connected in parallel to provide energy for the load 03 of the subsequent stage, which increases the occupied area of the multiphase voltage reduction circuit and limits the increase of the power density of the multiphase voltage reduction circuit.

Disclosure of Invention

The application provides a multiphase voltage reduction circuit, a filter circuit and electronic equipment, which can realize quick dynamic response, and reduce the occupied area of the multiphase voltage reduction circuit so as to further improve the power density of the multiphase voltage reduction circuit.

In a first aspect, the present application provides a multiphase voltage reduction circuit, an input terminal of the multiphase voltage reduction circuit is connected to a dc power supply, and an output terminal of the multiphase voltage reduction circuit is connected to a load, where in a typical application scenario, the load is a chip. The multiphase voltage reduction circuit comprises a controller, an auxiliary inductance module, a plurality of coupling windings and at least two-phase voltage reduction circuits. Each phase of the step-down circuit comprises a switch circuit and a filter circuit. The input end of the switching circuit is connected with a power supply, the output end of the switching circuit is connected with the input end of the filter circuit, and the output end of the filter circuit is connected with the output end of the multiphase voltage reduction circuit. The controller is used for controlling the switch circuit. The filter circuit comprises an output inductor and at least one output capacitor; the input end of the output inductor is the input end of the filter circuit, the output end of the output inductor is the output end of the filter circuit, the first end of at least one output capacitor is connected with the output end of the output inductor, and the second end of at least one output capacitor is grounded. The output inductor is electrically coupled to the auxiliary inductor module through a coupling winding. When the load current of the multiphase voltage reduction circuit is larger than the preset current, the inductance value of the auxiliary inductance module is a first inductance value; when the load current of the multiphase voltage reduction circuit is smaller than or equal to the preset current, the inductance value of the auxiliary inductance module is a second inductance value, and the first inductance value is smaller than the second inductance value. The inductance of the auxiliary inductance module when the load current of the multiphase voltage reduction circuit is larger than the preset current is smaller than the inductance of the auxiliary inductance module when the load current is smaller than or equal to the preset current.

By means of the scheme, when the load current of the multiphase voltage reduction circuit is smaller than or equal to the preset current, namely, the load current is in a steady state, ripple current in the output inductor is smaller, the inductance value of the auxiliary inductance module is larger, and the auxiliary inductance module is coupled with each output inductor through the coupling winding, so that after the inductance value of the auxiliary inductance module is increased, ripple current in the coupled auxiliary winding can be further reduced, ripple current in the output inductor is further reduced, the conduction loss and the switching loss of the switching tube are further reduced, and the alternating current resistance loss of the auxiliary winding is reduced, so that the circuit efficiency is improved. When the load current of the multiphase voltage reduction circuit is larger than the preset current, namely, when the rear-stage load connected with the multiphase voltage reduction circuit has large current, the ripple current of the output inductor is increased, and the inductance value of the auxiliary inductor module is smaller. Because the auxiliary inductance module is coupled with each output inductance through the coupling winding, after the inductance value of the auxiliary inductance module is reduced, the current of the output inductance in each phase of voltage reduction circuit is increased, so that the speed of the inductor current to catch up the load current is increased, the dynamic response speed of the multi-phase voltage reduction circuit is improved, more capacitors are not required to be arranged to provide energy for the later-stage load, the number of output capacitors can be reduced, the occupied area of the multi-phase voltage reduction circuit is reduced, and the power density of the multi-phase voltage reduction circuit is further improved.

In one possible implementation, the auxiliary inductance module includes one or more saturation inductances. When the auxiliary inductance module includes a plurality of saturation inductances, the plurality of saturation inductances may be connected in series or in parallel.

With this implementation, when the load current is in steady state, the ripple current in the output inductor is small, and thus the current in the saturation inductor is correspondingly small after the output inductor is coupled to the saturation inductor. The characteristic of the saturated inductor can be determined, and the inductance value of the saturated inductor is larger at the moment, so that ripple current in the coupled auxiliary winding can be further reduced, AC resistance loss of the auxiliary winding is reduced, ripple current in the output inductor is reduced, conduction loss and switching loss of the switching tube are reduced, and circuit efficiency is further improved.

When a high current appears in a later-stage load connected with the multi-phase voltage reduction circuit, the ripple current of the output inductor is increased, so that after the output inductor is coupled to the saturation inductor, the output inductor can be determined according to the characteristics of the saturation inductor, and the inductance value of the saturation inductor is smaller at the moment, so that other phase voltage reduction circuits are influenced, the current of the output inductor in each phase voltage reduction circuit is increased, the speed of the inductor current to catch up the load current is increased, and the dynamic response speed of the multi-phase voltage reduction circuit is improved. Therefore, more capacitors are not required to be arranged for providing energy for the subsequent load, the number of output capacitors can be reduced, the hardware cost is reduced, the occupied area is smaller, and the power density is higher.

In one possible implementation, the auxiliary inductor module includes a first set of saturated inductors and a second set of saturated inductors, and the multi-phase buck circuit includes a first set of buck circuits and a second set of buck circuits. The output inductance of at least one of the first group of voltage reduction circuits is electrically coupled with the first group of auxiliary inductance modules through a coupling winding respectively. The output inductors of the step-down circuits in the second group of step-down circuits are electrically coupled with the second group of auxiliary inductance modules through a coupling winding respectively. By arranging a plurality of saturation inductors, the efficiency of the multi-phase voltage reduction circuit in a steady state can be further improved, and the speed of dynamic response is further improved when a load generates a large current.

In one possible implementation, the auxiliary inductance module comprises at least two auxiliary inductance units connected in series. Each auxiliary inductance unit includes a switching tube and a first inductance connected in parallel. The controller controls the switching tube in each auxiliary inductance unit according to the load current. In one possible implementation, the controller controls the number of switching tubes in the auxiliary inductance module to be closed, which is positively correlated with the magnitude of the load current.

By adopting the implementation mode, when the load current is smaller, namely the load current is in a steady state, the closing quantity of the switching tube is small, and the inductance value of the auxiliary inductance module is larger, so that the ripple current in the coupled auxiliary winding can be further reduced, the alternating current resistance loss of the auxiliary winding is reduced, the ripple current in the output inductance is reduced, the conduction loss and the switching loss of the switching tube are reduced, and the circuit efficiency is further improved. When the load current is increased, the switch tube is closed more, the inductance of the series connection access circuit is reduced, so that the inductance value of the auxiliary inductance module is reduced, the speed of the inductance current to catch up the load current is further increased, and the dynamic response speed of the multiphase voltage reduction circuit is further improved.

In one possible implementation, the auxiliary inductance module comprises at least two auxiliary inductance branches connected in parallel. Each auxiliary inductance branch comprises a switching tube and a second inductance which are connected in series. The controller controls the switching tube in each auxiliary inductive branch according to the load current. In one possible implementation, the controller controls the number of switching tubes in the auxiliary inductance module to be closed, which is positively correlated with the magnitude of the load current.

By adopting the implementation mode, when the load current is smaller, namely the load current is in a steady state, the closing quantity of the switching tube is small, and the inductance value of the auxiliary inductance module is larger, so that the ripple current in the coupled auxiliary winding can be further reduced, the alternating current resistance loss of the auxiliary winding is reduced, the ripple current in the output inductance is reduced, the conduction loss and the switching loss of the switching tube are reduced, and the circuit efficiency is further improved. When the load current is increased, the switch tube is closed more, and the inductance of the parallel connection access circuit is increased, so that the inductance value of the auxiliary inductance module is reduced, the speed of the inductance current to catch up the load current is further increased, and the dynamic response speed of the multiphase voltage reduction circuit is further improved.

In one possible implementation, the switching circuit further comprises a driving circuit. The input end of the driving circuit is connected with the controller, and the output end of the driving circuit is connected with the control end of the first switching tube and the control end of the second switching tube. The driving circuit is used for controlling the first switching tube and the second switching tube according to a control signal output by the controller.

In a second aspect, the present application further provides a filter circuit, the filter circuit comprising: the auxiliary inductance module, a plurality of coupling windings, a plurality of output inductances and a plurality of output capacitances. The first end of each output inductor is an input end of the filter circuit, and the second end of each output inductor is connected with the output end of the filter circuit; a first end formed by connecting a plurality of output capacitors in parallel is connected with the output end of the filter circuit, and a second end formed by connecting a plurality of output capacitors in parallel is grounded; each output inductor is electrically coupled with the auxiliary inductor module through a coupling winding; when the load current of the filter circuit is larger than the preset current, the inductance value of the auxiliary inductance module is a first inductance value; when the load current of the filter circuit is smaller than or equal to the preset current, the inductance value of the auxiliary inductance module is a second inductance value, and the first inductance value is smaller than the second inductance value.

By means of the scheme, when the load current of the filter circuit is smaller than or equal to the preset current, namely, the load current is in a steady state, ripple current in the output inductor is smaller, the inductance value of the auxiliary inductor module is larger, and as the auxiliary inductor module is coupled with each output inductor through the coupling winding, the ripple current in the coupled auxiliary winding can be further reduced, the ripple current in the output inductor is further reduced, the conduction loss and the switching loss of the switching tube are further reduced, the alternating current resistance loss of the auxiliary winding is reduced, and the circuit efficiency is improved. When the load current of the filter circuit is larger than the preset current, namely, when the load of the later stage generates large current, the ripple current of the output inductor is increased, and the inductance value of the auxiliary inductor module is smaller at the moment.

In one possible implementation, the auxiliary inductor module includes a first set of saturated inductors and a second set of saturated inductors, and the filter circuit includes a first set of output inductors and a second set of output inductors. Each output inductor in the first group of output inductors is coupled with the first group of auxiliary inductance modules through a coupling winding respectively; each output inductor in the second group of output inductors is respectively coupled with the second group of auxiliary inductor modules through a coupling winding.

In one possible implementation, the auxiliary inductance module comprises at least two auxiliary inductance units connected in series. Each auxiliary inductance unit includes a switching tube and a first inductance connected in parallel.

In one possible implementation, the auxiliary inductance module comprises at least two auxiliary inductance branches connected in parallel. Each auxiliary inductance branch comprises a switching tube and a second inductance which are connected in series;

in a third aspect, the present application also provides an electronic device including a circuit board including a chip and a multiphase voltage reduction circuit provided by one or more of the above implementations. The multiphase voltage reduction circuit is used for supplying power to the chip. The output end of the multiphase voltage reduction circuit is connected with the power supply pin of the chip.

In one possible implementation, the circuit board includes a plurality of multi-phase buck circuits connected in parallel to provide sufficient operating current for the chip. The multiphase voltage reduction circuits are distributed on different sides of the chip, so that the length of a power transmission line when the chip is powered can be shortened, the line loss is further reduced, and the power transmission efficiency is improved.

In one possible implementation, the electronic device is a server.

Drawings

FIG. 1 is a schematic diagram of a multiphase voltage step-down circuit;

FIG. 2 is a schematic diagram of waveforms of PWM signals and inductor currents;

fig. 3 is a schematic diagram of a multiphase voltage reduction circuit according to an embodiment of the present disclosure;

FIG. 4 is a schematic diagram of another multi-phase buck circuit according to an embodiment of the present disclosure;

FIG. 5 is a schematic diagram of waveforms of PWM signals and inductor currents according to an embodiment of the present disclosure;

FIG. 6 is a schematic diagram of a multi-phase buck circuit according to an embodiment of the present disclosure;

FIG. 7 is a schematic diagram of coupling of the inductance of the area A in FIG. 6 according to an embodiment of the present application;

fig. 8 is an equivalent circuit diagram of area a in fig. 6 provided in an embodiment of the present application;

fig. 9 is a schematic diagram of a hysteresis loop of a saturation inductor according to an embodiment of the present disclosure;

FIG. 10 is a schematic diagram of a multi-phase buck circuit according to an embodiment of the present disclosure;

FIG. 11 is a schematic diagram of another multi-phase buck circuit according to an embodiment of the present disclosure;

FIG. 12 is a schematic diagram of a multi-phase buck circuit according to an embodiment of the present disclosure;

FIG. 13 is a schematic diagram of a multiphase voltage step-down circuit according to an embodiment of the present disclosure;

FIG. 14 is a schematic diagram of another multi-phase buck circuit according to an embodiment of the present disclosure;

fig. 15a is a schematic diagram of a filter circuit according to an embodiment of the present application;

FIG. 15b is a schematic diagram of another filtering circuit according to an embodiment of the present disclosure;

FIG. 15c is a schematic diagram of a further filtering circuit according to an embodiment of the present disclosure;

FIG. 15d is a schematic diagram of a further filtering circuit according to an embodiment of the present disclosure;

FIG. 15e is a schematic diagram of another filtering circuit according to an embodiment of the present disclosure;

FIG. 15f is a schematic diagram of a further filtering circuit according to an embodiment of the present disclosure;

FIG. 15g is a schematic diagram of a further filtering circuit according to an embodiment of the present disclosure;

fig. 16 is a schematic diagram of an electronic device according to an embodiment of the present application.

Detailed Description

In order to enable a person skilled in the art to better understand the technical solution provided in the embodiments of the present application, an application scenario of the technical solution of the present application is first described below.

Types of chips in the present application include, but are not limited to, central processing units (Central Processing Unit, CPU), graphics processors (Graphics Processing Unit, GPU), field programmable gate arrays (Field-programmable Gate Array, FPGA), and neural network processors (Neural network Processing Unit, NPU), among others.

Along with the continuous evolution of chips, the areas of the chips and the power supply types required by the chips are more and more, the power consumption is more and more, and the available area reserved for a power supply on a single board is smaller and less, so that the improvement of the power supply density of the power supply is critical.

In addition, the clock frequency of the chip is faster and faster, the working voltage is lower and the required working current is higher, and the working current is continuously and dynamically adjusted along with the change of the operation business.

For example, the current working voltage of some CPU cores is reduced to below 1V, the working current can reach 500A to 1000A or even above, and the dynamic change rate of the working current can reach above 1000A/mu s.

In order to adapt to the above working conditions of the chip, the multiphase voltage reduction circuit shown in fig. 1 is adopted when the chip is powered, and the overall output capacity of the VRM is improved by connecting multiple voltage reduction circuits in parallel and sharing input voltage and output voltage.

The controller of the multiphase voltage reduction circuit outputs PWM signals to respectively control the working states of the switching tubes in each phase of voltage reduction circuit.

Referring to fig. 2, waveforms of the PWM signal and the inductor current are shown.

Output inductance L ₂ The one-phase voltage-reducing circuit is illustrated as an example, and the corresponding PWMThe signal is PWM2. When the PWM2 is at a high level, the Q1 is conducted, the Q2 is closed, the inductor L2 stores energy, and the inductor current rises; when PWM2 is low, Q1 is on and Q2 is off, and the inductor current decreases. When the transient load changes in the subsequent stage, the step-down circuit with the high instantaneous PWM signal increases the duty ratio DeltaD of the PWM signal to increase the inductance current and further provide energy for the load, i _L2 The waveform of (a) corresponds to the dotted line part in FIG. 1, i.e.) _L2 Increasing.

At present, in order to reduce the conduction loss and the switching loss of a switching tube and improve the efficiency of a multi-phase voltage reduction circuit, the voltage reduction circuit of each phase generally adopts an inductor with a larger inductance value, so that the ripple current in the inductor is smaller when a load is steady, and the purposes are further achieved. The magnitude of the ripple in the inductance corresponds to iΔ in fig. 2.

However, when the load is subjected to transient loading, the inductor with smaller inductance value can increase the inductance current until the speed of the current required by the load is slower, namely the dynamic response speed is slow, so that more capacitors are required to be connected in parallel at the output end to provide energy for the load of the subsequent stage, the occupied area and the hardware cost of the multiphase voltage reduction circuit are increased, and the improvement of the power density of the multiphase voltage reduction circuit is also limited.

In addition, since the available area of the power supply on the single board is smaller and smaller, which contradicts the requirement of adding the capacitor, even if the available area on the single board is used up, the number of the capacitors is insufficient, so that the multi-phase voltage reduction circuit still cannot meet the requirement of quick dynamic response.

In order to solve the technical problem, the application provides a multiphase voltage reduction circuit, a filter circuit and electronic equipment, wherein an output inductor of the multiphase voltage reduction circuit is electrically coupled with an auxiliary inductor module through a coupling winding. The inductance of the auxiliary inductance module when the load current of the multiphase voltage reduction circuit is larger than the preset current is smaller than the inductance of the auxiliary inductance module when the load current is smaller than or equal to the preset current. According to the scheme, the circuit efficiency can be improved, the quick dynamic response is realized, the occupied area of the multiphase voltage reduction circuit is reduced, and the power density of the multiphase voltage reduction circuit is further improved.

In order to make the technical solution more clearly understood by those skilled in the art, the following description will refer to the technical solution in the embodiments of the present application with reference to the accompanying drawings in the embodiments of the present application.

The words "first," "second," and the like in the description herein are used for descriptive purposes only and are not to be interpreted as indicating or implying a relative importance or implicitly indicating the number of technical features indicated.

In the following examples of the present application, the remaining inductors refer to linear inductors except for the saturation inductors which are emphasized specifically.

The embodiment of the application provides a multiphase voltage reduction circuit, which is specifically described below with reference to the accompanying drawings.

Referring to fig. 3, a schematic diagram of a multiphase voltage step-down circuit according to an embodiment of the present application is shown.

The multiphase voltage reduction circuit includes: a controller 04 and at least two-phase voltage step-down circuit.

The number of the step-down circuits included in the multiphase step-down circuit is not particularly limited, and in practical application, the number of the step-down circuits can be determined according to the working current condition of the load.

Each phase of the step-down circuit includes a switching circuit 01 and a filter circuit 02. The filter circuit 02 is an LC filter circuit, i.e. the filter circuit comprises an output inductance and an output capacitance. The filter circuit 02 of the first-phase voltage-reducing circuit shown in fig. 3 includes a filter inductance L1 and a filter capacitance C1; the filter circuit 02 of the second-phase voltage reduction circuit comprises a filter inductor L2 and a filter capacitor C2; the filter circuit 02 of the n-th phase voltage step-down circuit includes a filter inductance Ln and a filter capacitance Cn. In practical application, component parameters adopted by the common phase voltage reduction circuit are consistent.

The input end of the switching circuit 01 is connected with a power supply, the output end of the switching circuit 01 is connected with the input end of the filter circuit, and the output end of the filter circuit is connected with the output end of the multiphase voltage reduction circuit. The controller 04 is used to control the switching circuit 01.

The filter circuit includes an output inductance and at least one output capacitance. The output inductances of the filter circuits are L1, L2, … and Ln. In the embodiments of the present application and the following description, taking an example that each filter circuit includes one output inductor, the implementation manner when each filter circuit includes a plurality of output inductors is similar, and will not be described herein again.

The input end of the output inductor is the input end of the filter circuit, the output end of the output inductor is the output end of the filter circuit, the first end of the output capacitor of the filter circuit is connected with the output end of the output inductor, and the second end of the output capacitor of the filter circuit is grounded. In the circuit shown in fig. 3, the output capacitors of the step-down circuits are connected in parallel.

The output inductance of each phase of the step-down circuit is electrically coupled with the auxiliary inductance module 06 through the coupling winding.

In the circuit shown in fig. 3, the coupling windings corresponding to the respective phase step-down circuits are all connected in series. In other implementations, the corresponding coupling windings of the partial step-down circuit may be connected in series, for example, see the schematic diagram of another multiphase step-down circuit shown in fig. 4.

In fig. 4, the coupling windings corresponding to every two voltage step-down circuits are connected in series and then electrically coupled with the auxiliary inductance module 06. It should be noted that fig. 4 is only one possible implementation manner, and the implementation manner when the coupling windings corresponding to the three or more step-down circuits are connected in series is similar, which is not described herein again.

The inductance of the auxiliary inductance module 06 when the load current of the multiphase voltage reduction circuit is larger than the preset current is smaller than the inductance of the auxiliary inductance module 06 when the load current of the multiphase voltage reduction circuit is smaller than or equal to the preset current.

The preset current may be determined according to an actual application scenario, and the embodiment of the present application is not specifically limited.

That is, in the present embodiment, the inductance value of the auxiliary inductance module 06 is not fixed, but dynamically changes with the load of the multiphase voltage reduction circuit.

Referring to fig. 5, a schematic diagram of waveforms of a PWM signal and an inductor current according to an embodiment of the present application is shown.

The one-phase voltage step-down circuit in which the output inductor L2 is shown in fig. 3 is taken as an example.

When the load current is in a steady state, i.e. the load current is less than or equal to the preset current, the ripple current in the output inductor L2 is small. At this time, the inductance value of the auxiliary inductance module 06 is larger, the auxiliary inductance module 06 is coupled to each phase of voltage reduction circuit, ripple current in the coupled auxiliary winding can be further reduced, alternating current resistance loss (alternating current resistance, ACR) of the auxiliary winding is reduced, the auxiliary inductance module 06 can reduce ripple current in the output inductance, conduction loss and switching loss of the switching tube are reduced, and circuit efficiency is further improved.

When a large current occurs to the subsequent load connected to the multiphase voltage reduction circuit during the control of the second phase voltage reduction circuit, the controller 04 increases the duty ratio of the control signal, and the increased duty ratio, that is, Δd in fig. 5, at this time, the ripple current of L2 increases. When the load current is larger than the preset current, the auxiliary inductance module 06 has an impact current, and the inductance value of the auxiliary inductance module 06 is smaller. The auxiliary inductance module 06 is coupled to each phase of voltage-reducing circuit, the current variation of the auxiliary inductance module 06 affects other phases of voltage-reducing circuits, so that the current of the output inductor in each phase of voltage-reducing circuit is increased, as shown by the waveform of the broken line part of the inductor current in fig. 5, thereby accelerating the speed of the inductor current to catch up with the load current, and improving the dynamic response speed of the multi-phase voltage-reducing circuit.

The scheme realizes the efficiency improvement of the multiphase voltage reduction circuit in a steady state and quick dynamic response by using the auxiliary inductance module 06, and in addition, the scheme can also improve the power density of the multiphase voltage reduction circuit when the multiphase voltage reduction circuit is used as a power supply to supply power to a load. This is because, based on analysis of the present layout situation of the current board, it is found that removing the load chip from the board, in some typical examples, about 80% of the area is the power source, that is, the multi-phase voltage reduction circuit, wherein the output capacitance of the multi-phase voltage reduction circuit is about 50% -60%, so that reducing the output capacitance of the multi-phase voltage reduction circuit is a powerful measure for increasing the power supply density. In the scheme of the application, when the load chip is subjected to transient loading, the auxiliary inductance module 06 can realize quick dynamic response, so that more capacitors do not need to be arranged to provide energy for the load at the later stage; i.e. the same number of capacitors is provided, more energy can be provided for the load of the subsequent stage. Therefore, the scheme of the application can reduce the number of output capacitors, reduce hardware cost, and also has smaller occupied area and higher power density.

Further, in some possible implementations, the output capacitor is a device with a larger failure risk, such as a tantalum capacitor, so that the number of output capacitors is reduced, and the reliability of the multiphase voltage reduction circuit can be improved.

The controller of an embodiment of the present application is an application specific integrated circuit (Application Specific Integrated Circuit, ASIC), a programmable logic device (Programmable Logic Device, PLD), a digital signal processor (Digital Signal Processor, DSP), or a combination thereof. The PLD may be a complex programmable logic device (Complex Programmable Logic Device, CPLD), a Field programmable gate array (Field-programmable Gate Array, FPGA), a general-purpose array logic (Generic Array Logic, GAL), or any combination thereof, and embodiments of the present application are not particularly limited.

The following description is made in connection with specific implementations.

The implementation when the auxiliary inductor module includes a saturation inductor (saturable inductor) is first described below.

Referring to fig. 6, a schematic diagram of another multiphase voltage step-down circuit according to an embodiment of the present application is shown.

The multiphase voltage step-down circuit shown in fig. 6 includes a controller 04 and at least two-phase voltage step-down circuits. Each phase of the step-down circuit comprises a switch circuit 01 and a filter circuit.

The switching circuit 01 includes a first switching tube Q1, a second switching tube Q2, and a driving circuit 10.

The first end of the first switching tube Q1 is connected with the input end of the switching circuit 01, the second end of the first switching tube Q1 is connected with the first end of the second switching tube Q2 and the output end of the switching circuit 01, and the second end of the second switching tube Q2 is grounded.

The first and second switching transistors Q1 and Q2 may be insulated gate bipolar transistors (Insulated Gate Bipolar Transistor, IGBT), metal oxide semiconductor field effect transistors (Metal Oxide Semiconductor Filed Effect Transistor, MOSFET, MOS transistor for short), silicon carbide field effect transistors (Silicon Carbide Metal Oxide Semiconductor, siC MOSFET), or the like. The embodiment of the present application is not particularly limited thereto.

An input end of the driving circuit 10 is connected with the controller 04, and an output end of the driving circuit 10 is connected with a control end of the first switching tube Q1 and a control end of the second switching tube Q2. Taking the Q1 and Q2 as MOS transistors, and specifically as NMOS transistors as examples, the first end of the switch transistor is a drain electrode, the second end is a source electrode, and the control end is a grid electrode.

The driving Circuit (driving Circuit) 10 is used for controlling the operation states of the first switching tube Q1 and the second switching tube Q2 according to the control signal output by the controller 04.

In one possible implementation, the switching circuit 01 is a DrMOS chip, in which switching transistors Q1 and Q2 are integrated, and Q1 and Q2 are metal oxide semiconductor field effect transistors (Metal Oxide Semiconductor Filed Effect Transistor, MOSFETs), and in which the driving circuit 10 is also integrated.

The controller 04 is configured to send pulse width modulation (Pulse Width Modulation, PWM) signals to each driving circuit 10 to control the switching tubes of the voltage step-down circuits of each phase to be alternately turned on, thereby reducing ripple of the output current and reducing ripple of the output voltage.

The auxiliary inductance module 06 shown in the figure comprises a saturation inductance Lc, also called a saturable reactor or self-saturating inductance, which is a special form of inductor in which the current in the winding can saturate the core of the winding. Once the core of the winding is saturated, the inductance value of the saturated inductor decreases. This reduces the inductive reactance and causes the inductor current to increase. That is, the saturation inductor has a certain initial inductance value, where the initial inductance value refers to an inductance value when no current flows in the saturation inductor, and as the current increases, the current in the saturation inductor gradually decreases to a certain ratio less than the initial inductance value, for example, less than 50% of the initial inductance value. The specific parameters of the applied saturation inductance Lc in the embodiment of the present application are not specifically limited, and may be determined according to actual situations.

See also fig. 7 and 8. Fig. 7 is a schematic diagram of coupling of the inductance of the region a in fig. 6 according to an embodiment of the present application; fig. 8 is an equivalent circuit diagram of area a in fig. 6 provided in an embodiment of the present application.

The output inductors L1, L2, …, ln of the multiphase step-down circuit are electrically coupled to the saturation inductor Lc through the following coupling windings, respectively. For convenience of illustration, the number of winding turns of each output inductor and the coupling winding in fig. 7 is only one of the turns, and in practical application, the number of winding turns may be multiple turns.

Lr in fig. 8 is equivalent leakage inductance, lm1, …, lmn, respectively, is equivalent excitation inductance. Referring to fig. 9 for a schematic diagram of the hysteresis loop of the saturation inductance Lc, the gray area corresponds to the saturation inductance and the white area corresponds to the normal linear inductance in fig. 9, it can be seen that: the saturated inductor has the characteristic of exhibiting a small inductance value at a large current and exhibiting a large inductance value at a small current.

The following describes the operation principle of the saturated inductor Lc by taking the one-phase voltage step-down circuit in which the output inductor L2 is located as an example.

When the load current is in steady state, the ripple current in the output inductor L2 is small, so that after L2 is coupled to Lc, the current in Lc is correspondingly small. According to the characteristic of Lc, it can be determined that the inductance value of Lc is larger at this time, so after Lc is coupled to the output inductance of the step-down circuit of each phase, the ripple current in the coupled auxiliary winding can be further reduced, the ac resistance loss of the auxiliary winding is reduced, the ripple current in the output inductance is reduced, the conduction loss and the switching loss of the switching tube are reduced, and further the circuit efficiency is improved.

When a large current occurs to the subsequent load connected to the multiphase voltage reduction circuit during the control of the second phase voltage reduction circuit, the controller increases the duty ratio of the control signals to Q1 and Q2, i.e., Δd in fig. 5, so that the on time of Q1 is prolonged and the off time of Q2 is prolonged. At this time, the ripple current of L2 increases. Thus, after L2 is coupled to Lc, there is an inrush current in Lc. It can be determined from the characteristics of Lc when the inductance value of Lc is small. After Lc is coupled to the output inductor of each phase of voltage-reducing circuit, the current variation of Lc affects other phases of voltage-reducing circuits, so that the current of the output inductor in each phase of voltage-reducing circuit is increased, as shown by the waveform of the dotted line part of the inductor current in fig. 5, so that the speed of the inductor current to catch up with the load current is increased, and the dynamic response speed of the multi-phase voltage-reducing circuit is improved.

The scheme realizes the efficiency improvement and the rapid dynamic response of the multiphase voltage reduction circuit in a steady state by using the saturated inductor Lc, and in addition, the scheme can also improve the power density of the multiphase voltage reduction circuit when the multiphase voltage reduction circuit is used as a power supply to supply power to a load, because the rapid dynamic response can be realized by using the saturated inductor Lc when the load chip is subjected to transient loading, and more capacitors are not required to be arranged to supply energy for the load at the later stage; i.e. the same number of capacitors is provided, more energy can be provided for the load of the subsequent stage. Therefore, the scheme of the application can reduce the number of output capacitors, reduce hardware cost, and also has smaller occupied area and higher power density.

Further, in some possible implementations, the output capacitor is a device with a larger failure risk, such as a tantalum capacitor, so that the number of output capacitors is reduced, and the reliability of the multiphase voltage reduction circuit can be improved. In addition, the output inductors of the multiphase voltage reduction circuit are electrically coupled with the saturation inductor Lc through the auxiliary winding, and the mode does not need to be directly connected with each other physically, so that the layout flexibility is high.

The auxiliary inductor module in the above embodiment includes a saturation inductor, and in practical application, the auxiliary inductor module may also include a plurality of saturation inductors, which will be described in detail with reference to the accompanying drawings.

Referring to fig. 10, a schematic diagram of still another multiphase voltage step-down circuit according to an embodiment of the present application is shown.

The difference between the multiphase voltage reduction circuit shown in fig. 10 and fig. 6 is that the auxiliary inductance module 06 includes m saturation inductances, where m is an integer greater than or equal to 2. Wherein, m saturated inductances are connected in parallel.

At this time, the ripple current in the output inductor is regulated by the m saturated inductors together, when the high current appears in the later-stage load connected with the multiphase voltage reduction circuit, the inductance value of the m saturated inductors after being connected in parallel is smaller, so that the current of the output inductor in each phase of voltage reduction circuit can be increased more rapidly, and the dynamic response speed of the multiphase voltage reduction circuit is further improved.

Referring to fig. 11, a schematic diagram of another multiphase voltage step-down circuit according to an embodiment of the present application is shown.

The difference between the multiphase voltage reduction circuit shown in fig. 11 and fig. 6 is that the auxiliary inductance module 06 includes m saturation inductances, where m is an integer greater than or equal to 2. Wherein, m saturated inductances are connected in series.

At this time, the ripple current in the output inductor is regulated by the m saturated inductors together, when the load current is in a steady state, the inductance value of the m saturated inductors after being connected in series is larger, so that the inductance value of the auxiliary inductance module 06 is larger, after the auxiliary inductance module 06 is coupled to the output inductor of each phase of voltage reduction circuit, the ripple current in the coupled auxiliary winding can be further reduced, the alternating current resistance loss of the auxiliary winding is reduced, the ripple current in the output inductor is further reduced, the conduction loss and the switching loss of the switching tube are reduced, and the circuit efficiency is further improved.

And after a plurality of saturation inductors are connected in series, the inductance change range of the auxiliary inductance module 06 is wider, so that the method can be suitable for a scene that load current fluctuates in a larger range.

In other embodiments, the auxiliary inductor module 06 includes at least two sets of saturation inductors: a first set of saturated inductances and a second set of saturated inductances. The multiphase voltage reduction circuit at least comprises the following two groups of voltage reduction circuits: a first set of buck circuits and a second set of buck circuits. Each of the first set of saturated inductors and the second set of saturated inductors includes at least one saturated inductor. Each of the first group of voltage-reducing circuits and the second group of voltage-reducing circuits comprises at least one voltage-reducing circuit; the output inductances of the step-down circuits in the first group of step-down circuits are electrically coupled with the first group of auxiliary inductance modules through coupling windings respectively; the output inductors of the step-down circuits in the second set of step-down circuits are electrically coupled to the second set of auxiliary inductor modules through a coupling winding, respectively, and are described in detail below with reference to the accompanying drawings.

Referring to fig. 12, a schematic diagram of another multiphase voltage step-down circuit according to an embodiment of the present application is shown.

The illustration is given by taking an example that each group of saturated inductors comprises one saturated inductor, and each group of voltage reduction circuits comprises two voltage reduction circuits. The principle is similar when a greater number of saturated inductors are included in each group of saturated inductors, or a greater number of step-down circuits are included in each group of step-down circuits, and will not be described again. When a plurality of saturation inductors are included in each group of saturation inductors, the plurality of saturation inductors may be connected in parallel or in series.

That is, the output inductance of every two voltage step-down circuits is electrically coupled with one saturation inductance through the coupling winding, the auxiliary inductance module 06 comprises m saturation inductances, the multiphase voltage step-down circuit comprises an n-phase voltage step-down circuit, and m is one half of n.

The above embodiment can be seen that the above scheme utilizes the saturation inductance to realize the efficiency improvement of the multiphase voltage reduction circuit in steady state and rapid dynamic response, and in addition, the mode can also carry out flexible layout, thereby having higher practicability.

Another implementation of the auxiliary inductance module is described below.

Referring to fig. 13, a schematic diagram of still another multiphase voltage step-down circuit according to an embodiment of the present application is shown.

The multiphase voltage step-down circuit shown in fig. 13 includes a controller 04 and at least two-phase voltage step-down circuits. Each phase of the step-down circuit comprises a switch circuit 01 and a filter circuit.

An input end of the driving circuit 10 is connected with the controller 04, and an output end of the driving circuit 10 is connected with a control end of the first switching tube Q1 and a control end of the second switching tube Q2. The driving circuit 10 is used for controlling the working states of the first switching tube Q1 and the second switching tube Q2 according to the control signal output by the controller 04.

The auxiliary inductance module 06 comprises at least two auxiliary inductance units connected in series: a first auxiliary inductance unit 61 and a second auxiliary inductance unit 62.

Each auxiliary inductance unit includes a switching tube and a linear inductance connected in parallel. Specifically, the first auxiliary unit 61 includes Lc1 and S1 connected in parallel, and the second auxiliary unit 62 includes Lc2 and S2 connected in parallel.

The controller 04 is used to control the switching tubes in each auxiliary inductive unit in accordance with the load current.

In one possible implementation, the controller 04 sends control signals to the driving circuits corresponding to S1 and S2 to cause the driving circuits to control the operating states of S1 and S2.

The controller 04 changes the inductance of the auxiliary inductance module 06 by controlling the switching tube in each auxiliary inductance unit to be turned on or off. In one possible implementation, the magnitude of the load current is positively correlated with the number of closures of the switching tubes in the auxiliary inductance module. In practical application, the corresponding relation between the load current and the number of the closed switch tubes can be calibrated and stored in advance, and the corresponding relation is called when the controller 04 is used.

The inductance values of the linear inductance Lc1 and the linear inductance Lc2 are L0, for example.

When the controller 04 controls both S1 and S2 to be turned off, the linear inductor Lc1 and the linear inductor Lc2 are connected in series, and the inductance value of the auxiliary inductance module 06 is 2L0.

When the controller 04 controls the opening of the S1 and the closing of the S2, the linear inductor Lc1 is connected to the circuit, the linear inductor Lc2 is shorted, and the inductance value of the auxiliary inductor module 06 is L0. Or when the controller 04 controls the on/off of the S1 and the off of the S2, the linear inductor Lc2 is connected to the circuit, the linear inductor Lc1 is shorted, and the inductance value of the auxiliary inductor module 06 is L0.

When the controller 04 controls both S1 and S2 to be closed, the inductance value of the auxiliary inductance module 06 is 0.

When the load current is in a steady state, ripple current in the output inductor L2 is smaller, at this moment, the controller can control the S1 and the S2 to be disconnected so that the Lc1 and the Lc2 are connected in series, at this moment, the inductance value of the auxiliary inductor module 06 is larger, therefore, after the auxiliary inductor module 06 is coupled to the output inductor of the voltage reduction circuit of each phase, the ripple current in the coupled auxiliary winding can be further reduced, the alternating current resistance loss of the auxiliary winding is reduced, the ripple current in the output inductor is reduced, the conduction loss and the switching loss of the switching tube are reduced, and further the circuit efficiency is improved.

When a large current occurs to the subsequent load connected to the multiphase voltage reduction circuit during the control of the second phase voltage reduction circuit, the controller increases the duty ratio of the control signals to Q1 and Q2, i.e., Δd in fig. 5, so that the on time of Q1 is prolonged and the off time of Q2 is prolonged. At this time, the ripple current of L2 increases. At this time, the controller controls one of the switching tubes S1 and S2 to be opened and the other switching tube to be closed, so that the inductance value of the auxiliary inductance module 06 is reduced. After the auxiliary inductance module 06 is coupled to the output inductance of each phase of voltage-reducing circuit, other phases of voltage-reducing circuits are affected, so that the current of the output inductance in each phase of voltage-reducing circuit is increased, as shown by the waveform of the broken line part of the inductance current in fig. 5, the speed of the inductance current to catch up the load current is increased, and the dynamic response speed of the multi-phase voltage-reducing circuit is improved.

When more remarkable heavy current appears in the later-stage load, the controller can control the S1 and the S2 to be closed so as to minimize the inductance value of the auxiliary inductance module 06, thereby further accelerating the speed of the inductance current to catch up with the load current and further improving the dynamic response speed of the multiphase voltage reduction circuit.

In the above embodiment, only the implementation manner when the auxiliary inductance module 06 includes two auxiliary inductance units is illustrated, and the principle when the auxiliary inductance module 06 includes a greater number of auxiliary inductance units is similar, which will not be described herein.

The scheme realizes the efficiency improvement and the rapid dynamic response of the multiphase voltage reduction circuit in a steady state by using the auxiliary inductance module, and in addition, the scheme can also improve the power density of the multiphase voltage reduction circuit when the multiphase voltage reduction circuit is used as a power supply to supply power to a load, because the rapid dynamic response can be realized by using the auxiliary inductance module when a load chip is subjected to transient loading, more capacitors do not need to be arranged to provide energy for a later-stage load; i.e. the same number of capacitors is provided, more energy can be provided for the load of the subsequent stage. Therefore, the scheme provided by the embodiment of the application can reduce the number of output capacitors, reduce the hardware cost, and also has smaller occupied area and higher power density.

Further, in some possible implementations, the output capacitor is a device with a larger failure risk, such as a tantalum capacitor, so that the number of output capacitors is reduced, and the reliability of the multiphase voltage reduction circuit can be improved. And each output inductor of the multiphase voltage reduction circuit is electrically coupled with the auxiliary inductor module through the auxiliary winding, and the mode does not need to be directly connected with each output inductor physically, so that the layout flexibility is high.

A further implementation of the auxiliary inductance module is described below.

Referring to fig. 14, a schematic diagram of still another multiphase voltage step-down circuit according to an embodiment of the present application is shown.

The multiphase voltage step-down circuit shown in fig. 14 includes a controller 04 and at least two-phase voltage step-down circuits. Each phase of the step-down circuit comprises a switch circuit 01 and a filter circuit.

An input end of the driving circuit 10 is connected with the controller 04, and an output end of the driving circuit 10 is connected with a control end of the first switching tube Q1 and a control end of the second switching tube Q2. The driving circuit 10 is used for controlling the working states of the first switching tube Q1 and the second switching tube Q2 according to the control signal output by the controller 04. The controller 04 is configured to send a pwm signal to each driving circuit 10 to control the switching transistors of the voltage-reducing circuits of each phase to be alternately turned on, thereby reducing ripple of the output current and reducing ripple of the output voltage.

The auxiliary inductance module 06 comprises at least two auxiliary inductance branches connected in parallel: the first auxiliary inductance branch and the second auxiliary inductance branch.

Each auxiliary inductive leg comprises a switching tube and a linear inductance connected in series. Specifically, the first auxiliary inductive branch comprises Lc1 and S1 connected in series, and the second auxiliary inductive branch comprises Lc2 and S2 connected in series.

The controller 04 changes the inductance of the auxiliary inductance module 06 by controlling the switching tube in each auxiliary inductance branch to be turned on or off. In one possible implementation, the magnitude of the load current is positively correlated with the number of closures of the switching tubes in the auxiliary inductance module. In practical application, the corresponding relation between the load current and the number of the closed switch tubes can be calibrated and stored in advance, and the corresponding relation is called when the controller 04 is used.

When the controller 04 controls the opening of the S1 and the closing of the S2, the linear inductor Lc2 is connected to the circuit, and the inductance value of the auxiliary inductor module 06 is L0. Or when the controller 04 controls the S1 to be closed and the S2 to be opened, the linear inductor Lc1 is connected to the circuit, and the inductance value of the auxiliary inductor module 06 is L0.

When the controller 04 controls both the S1 and the S2 to be closed, the linear inductor Lc1 and the linear inductor Lc2 are connected in parallel and then connected into a circuit, and the inductance value of the auxiliary inductor module 06 is L0/2.

When the load current is in a steady state, ripple current in the output inductor L2 is smaller, at the moment, the controller can control one of the switches S1 and S2 to be closed, and the other switch is turned off, so that Lc1 or Lc2 is connected into the circuit, at the moment, the inductance value of the auxiliary inductor module 06 is larger, therefore, after the auxiliary inductor module 06 is coupled to the output inductor of the voltage reduction circuit of each phase, the ripple current in the coupled auxiliary winding can be further reduced, the alternating current resistance loss of the auxiliary winding is reduced, the ripple current in the output inductor is reduced, the conduction loss and the switching loss of the switching tube are reduced, and further the circuit efficiency is improved.

When a large current occurs to the subsequent load connected to the multiphase voltage reduction circuit during the control of the second phase voltage reduction circuit, the controller increases the duty ratio of the control signals to Q1 and Q2, i.e., Δd in fig. 5, so that the on time of Q1 is prolonged and the off time of Q2 is prolonged. At this time, the ripple current of L2 increases. At this time, the controller controls S1 and S2 to be both closed, and at this time Lc1 and Lc2 are connected in parallel and then connected to the circuit, so that the inductance value of the auxiliary inductance module 06 is reduced. After the auxiliary inductance module 06 is coupled to the output inductance of each phase of voltage-reducing circuit, other phases of voltage-reducing circuits are affected, so that the current of the output inductance in each phase of voltage-reducing circuit is increased, as shown by the waveform of the broken line part of the inductance current in fig. 5, the speed of the inductance current to catch up the load current is increased, and the dynamic response speed of the multi-phase voltage-reducing circuit is improved.

In the above embodiment, only the implementation manner when the auxiliary inductance module 06 includes two auxiliary inductance branches is illustrated, and the principle when the auxiliary inductance module 06 includes a greater number of auxiliary inductance branches is similar, which is not described herein.

Based on the multiphase voltage reduction circuit provided in the above embodiment, the embodiment of the application further provides a filter circuit, which is specifically described below with reference to the accompanying drawings.

Referring to fig. 15a, a schematic diagram of a filtering circuit according to an embodiment of the present application is shown.

The filter circuit includes: the auxiliary inductance module 06, a plurality of coupling windings, a plurality of output inductances and a plurality of output capacitances.

The output inductances are L1, L2, …, ln, respectively.

The first end of each output inductor is an input end of the filter circuit, and each input end in the figure is marked by Vi1, vi2, … and Vin in sequence, wherein n is an integer greater than or equal to 2. The second end of each output inductor is connected with the output end Vout of the filter circuit.

The first end formed by connecting the plurality of output capacitors in parallel is connected with the output end of the filter circuit, and the second end formed by connecting the plurality of output capacitors in parallel is grounded.

The output inductances are electrically coupled to the auxiliary inductance module 06 via a coupling winding.

The inductance of the auxiliary inductance module when the load current of the filter circuit is larger than the preset current is smaller than the inductance of the auxiliary inductance module when the load current is smaller than or equal to the preset current.

In a typical application scenario, the multi-phase filter circuit is applied to a multi-phase voltage-reducing circuit, where each input end of the filter circuit is connected to a switch circuit to form a one-phase voltage-reducing circuit, and an output end of the filter circuit is an output end of the multi-phase voltage-reducing circuit.

The implementation of the filter circuit is described in detail below.

Referring to fig. 15b, a schematic diagram of another filtering circuit according to an embodiment of the present application is shown.

The auxiliary inductance module 06 includes a saturation inductance Lc, lc having a determined initial inductance value, where the initial inductance value refers to an inductance value of the saturation inductance when no current flows through the saturation inductance, and the current of the saturation inductance gradually decreases to a certain ratio less than the initial inductance value, for example, less than 50% of the initial inductance value with increasing current. The specific parameters of the applied saturation inductance Lc in the embodiment of the present application are not specifically limited, and may be determined according to actual situations.

The principle of operation of the filter circuit is described below with respect to the application of the filter circuit to a multiphase buck circuit.

When the load current of the multiphase voltage reduction circuit is in a steady state, the ripple current in the output inductor is smaller, so that the current in Lc is correspondingly smaller after the output inductor is coupled to Lc. According to the characteristic of Lc, it can be determined that the inductance value of Lc is larger at this time, so after Lc is coupled to the output inductance of the step-down circuit of each phase, the ripple current in the coupled auxiliary winding can be further reduced, the ac resistance loss of the auxiliary winding is reduced, the ripple current in the output inductance is reduced, the conduction loss and the switching loss of the switching tube are reduced, and the circuit efficiency is further improved

When a large current occurs to a subsequent load connected to the multiphase voltage reduction circuit, the controller increases the duty ratio of the control signal to increase the ripple current of the output inductor. Thus, the output is inductively coupled to Lc, causing Lc to generate an inrush current. It can be determined from the characteristics of Lc when the inductance value of Lc is small. After Lc is coupled to the output inductor of each phase of voltage-reducing circuit, the current change of Lc affects other phases of voltage-reducing circuits, so that the current of the output inductor in each phase of voltage-reducing circuit is increased, the speed of the inductor current to catch up the load current is increased, and the dynamic response speed of the multi-phase voltage-reducing circuit is improved.

The filter circuit can realize quick dynamic response by using the saturated inductor Lc, so that more capacitors do not need to be arranged to provide energy for the load at the later stage; i.e. the same number of capacitors is provided, more energy can be provided for the load of the subsequent stage. Therefore, the scheme of the application can reduce the number of output capacitors, reduce hardware cost, and also has smaller occupied area and higher power density.

Further, in some possible implementations, the output capacitor uses a device with a larger failure risk, such as a tantalum capacitor, so that the number of output capacitors is reduced, and the reliability of the filter circuit can be further improved. The output inductors of the filter circuit are electrically coupled to the saturation inductor Lc through the auxiliary winding, and this eliminates the need for physically and directly connecting the output inductors, so that the flexibility of layout is high.

Referring to fig. 15c, a schematic diagram of another filtering circuit according to an embodiment of the present application is shown.

The difference between the filter circuit shown in fig. 15c and fig. 15b is that the auxiliary inductance module 06 includes m saturation inductances, where m is an integer greater than or equal to 2. Wherein, m saturated inductances are connected in parallel.

At this time, the ripple current in the output inductor is regulated by the m saturated inductors together, and when a high current appears in a later-stage load connected with the multiphase voltage reduction circuit, the inductance value of the m saturated inductors after being connected in parallel is smaller, so that the current of the output inductor in each phase of voltage reduction circuit can be increased more rapidly, and the dynamic response speed of the multiphase voltage reduction circuit is further improved.

Referring to fig. 15d, a schematic diagram of still another filtering circuit according to an embodiment of the present application is shown.

The difference between the filter circuit shown in fig. 15d and fig. 15b is that the auxiliary inductance module 06 includes m saturation inductances, where m is an integer greater than or equal to 2. Wherein, m saturated inductances are connected in series.

In other embodiments, the auxiliary inductor module includes at least two sets of saturation inductors: the filter circuit at least comprises the following two groups of output inductances: a first set of output inductances and a second set of output inductances. The first group of saturated inductors and the second group of saturated inductors respectively comprise at least one saturated inductor, and the first group of output inductors and the second group of output inductors respectively comprise at least one output inductor. Each output inductor in the first group of output inductors is electrically coupled with the first group of auxiliary inductor modules through a coupling winding, and each output inductor in the second group of output inductors is electrically coupled with the second group of auxiliary inductor modules through a coupling winding. In the following, it is described in detail with reference to the accompanying drawings.

Referring to fig. 15e, a schematic diagram of another filtering circuit according to an embodiment of the present application is shown.

The illustration is given by taking as an example that each set of saturation inductors comprises one saturation inductor and each set of output inductors comprises one output inductor. The principle is similar when a greater number of saturation inductors are included in each set of saturation inductors, or a greater number of output inductors are included in each set of output inductors, and will not be described in detail herein. When a plurality of saturation inductors are included in each group of saturation inductors, the plurality of saturation inductors may be connected in parallel or in series.

That is, every two output inductors are electrically coupled with one saturation inductor through the coupling winding, the auxiliary inductor module 06 comprises m saturation inductors, the filter circuit comprises n output inductors, and m is one half of n.

The embodiment can be seen that the above scheme realizes the efficiency improvement of the filter circuit in a steady state by using the saturation inductor and quick dynamic response, and in addition, the mode can also be flexibly distributed, so that the filter circuit has higher practicability.

Referring to fig. 15f, a schematic diagram of another filtering circuit according to an embodiment of the present application is shown.

In practical applications, the controller 04 controls the switching tube in each auxiliary inductance unit to be turned on or off to change the inductance of the auxiliary inductance module 06. In one possible implementation, the magnitude of the load current is positively correlated with the number of closures of the switching tubes in the auxiliary inductance module.

When the load current is in a steady state, the controller can control the S1 and the S2 to be disconnected so that the Lc1 and the Lc2 are connected in series, and the inductance value of the auxiliary inductance module 06 is larger at the moment, so that after the auxiliary inductance module 06 is coupled to each output inductance, the ripple current in the coupled auxiliary winding can be further reduced, the alternating current resistance loss of the auxiliary winding is reduced, the ripple current in the output inductance is reduced, the conduction loss and the switching loss of the switching tube are reduced, and the circuit efficiency is further improved.

When a high current occurs to the load at the later stage, the controller controls the ripple current of the output inductor to increase. At this time, the controller controls one of the switching tubes S1 and S2 to be opened and the other switching tube to be closed, so that the inductance value of the auxiliary inductance module 06 is reduced. After the auxiliary inductance module 06 is coupled to the output inductance of each phase of voltage-reducing circuit, other phases of voltage-reducing circuits are affected, so that the current of the output inductance in each phase of voltage-reducing circuit is increased, the speed of the inductor current to catch up the load current is increased, and the dynamic response speed of the multi-phase voltage-reducing circuit is improved.

When more remarkable heavy current appears in the later-stage load, the controller can control the S1 and the S2 to be disconnected so as to minimize the inductance value of the auxiliary inductance module 06, thereby further accelerating the speed of the inductance current to catch up with the load current and further improving the dynamic response speed of the multiphase voltage reduction circuit.

Referring to fig. 15g, a schematic diagram of still another filtering circuit according to an embodiment of the present application is shown.

In practical applications, the controller 04 changes the inductance of the auxiliary inductance module 06 by controlling the switching tube in each auxiliary inductance branch to be turned on or off. In one possible implementation, the magnitude of the load current is positively correlated with the number of closures of the switching tubes in the auxiliary inductance module.

When the load current is in a steady state, ripple current in the output inductor is smaller, at the moment, the controller can control one of the switches S1 and S2 to be closed, and the other switch to be turned off, so that Lc1 or Lc2 is connected into the circuit, at the moment, the inductance value of the auxiliary inductor module 06 is larger, therefore, after the auxiliary inductor module 06 is coupled to the output inductor of each phase of the voltage reduction circuit, the ripple current in the coupled auxiliary winding can be further reduced, the alternating current resistance loss of the auxiliary winding is reduced, the ripple current in the output inductor is reduced, the conduction loss and the switching loss of the switching tube are reduced, and the circuit efficiency is further improved.

When a high current occurs to the load at the later stage, the controller controls the ripple current of the output inductor to increase. At this time, the controller controls S1 and S2 to be both closed, and at this time Lc1 and Lc2 are connected in parallel and then connected to the circuit, so that the inductance value of the auxiliary inductance module 06 is reduced. After the auxiliary inductance module 06 is coupled to the output inductance of each phase of voltage-reducing circuit, other phases of voltage-reducing circuits are affected, so that the current of the output inductance in each phase of voltage-reducing circuit is increased, the speed of the inductor current to catch up the load current is increased, and the dynamic response speed of the multi-phase voltage-reducing circuit is improved.

In summary, by using the filter circuit provided by the embodiment of the application, the efficiency of the multiphase voltage reduction circuit in steady state is improved, the rapid dynamic response is realized, the number of output capacitors is reduced, the hardware cost is reduced, and the filter circuit has smaller occupied area and higher power density. Further, in some possible implementations, the output capacitor uses a device with a larger failure risk, such as a tantalum capacitor, so that the number of output capacitors is reduced, and the reliability of the filter circuit can be further improved. And each output inductor of the filter circuit is electrically coupled with the auxiliary inductor module through the auxiliary winding, and the mode does not need to be directly connected with each output inductor physically, so that the layout flexibility is high.

Based on the multiphase voltage reduction circuit provided in the above embodiment, the embodiment of the application also provides an electronic device using the multiphase voltage reduction circuit, and the following description is specific with reference to the accompanying drawings.

Referring to fig. 16, a schematic diagram of an electronic device according to an embodiment of the present application is provided.

The electronic device 160 includes one or more multi-phase buck circuits and also includes a chip 161. The embodiment of the present application is described by taking the electronic device 160 including the multiphase voltage reduction circuits 162a and 162b as an example, and the principle when other numbers are included is similar, and will not be repeated here.

Types of chips 161 in embodiments of the present application include, but are not limited to, a central processing unit (Central Processing Unit, CPU), a graphics processor (Graphics Processing Unit, GPU), a Field programmable gate array (Field-programmable Gate Array, FPGA), and a neural network processor (Neural network Processing Unit, NPU), among others.

The chip 161 is supplied with power from the multiphase voltage reduction circuits 162a and 162b as loads of the multiphase voltage reduction circuits 162a and 162 b.

Specifically, the output terminals of the multiphase voltage reduction circuits 162a and 162b may be connected in parallel and then connected to the input terminal of the chip 161, and the ground terminal of the chip 161 is connected to the ground terminals of the multiphase voltage reduction circuits 162a and 162 b.

The multiphase voltage reduction circuits 162a and 162b are specifically configured to reduce the voltage provided by the external power supply and output the reduced voltage to the power supply pin of the chip 161, and since the output ends of the multiphase voltage reduction circuits 162a and 162b2 are connected in parallel, a large current required for the operation of the chip 161 can be provided, and the magnitude of the working current required for the chip 161 is not specifically limited in this embodiment.

When the chip 161 is powered by a plurality of multi-phase voltage dropping circuits, which are disposed on different sides of the chip 161 when laid out on a printed circuit board (Printed Circuit Board, PCB), the transmission line length at the time of power supply is generally shortened. When the chip 161 shown in fig. 16 is supplied with power by the multiphase voltage reducing circuits 162a and 162b, the multiphase voltage reducing circuits 162a and 162b are provided on opposite sides of the chip 161.

With respect to the working principle and specific implementation of the multiphase voltage reduction circuit, reference may be made to the related description in the above embodiments, and the embodiments of the present application are not repeated herein.

The electronic device includes, but is not limited to, a server, a switch, a base station device, etc., and the embodiment of the present application does not specifically limit the type of the electronic device.

The electronic equipment utilizes the auxiliary inductance module to realize the efficiency improvement of the multiphase voltage reduction circuit in a steady state and quick dynamic response, so that the operation performance of the electronic equipment is improved. In addition, the scheme can also improve the power density when the multiphase voltage reduction circuit is used as a power supply to supply power for the load chip. The auxiliary inductance module is used for realizing quick dynamic response when the load chip is subjected to transient loading, so that more capacitors are not required to be arranged for supplying energy to the load at the later stage; i.e. the same number of capacitors is provided, more energy can be provided for the load of the subsequent stage. Therefore, the scheme of the application can reduce the quantity of output capacitors, further can reduce the hardware cost of the electronic equipment, and has smaller occupied area and higher power density so as to facilitate the layout design of the hardware of the electronic equipment.

Further, in some possible implementations, the output capacitor is a device with a larger failure risk, such as a tantalum capacitor, so that the number of output capacitors is reduced, the reliability of the multiphase voltage reduction circuit is further improved, and the reliability of the electronic device is also improved.

It should be understood that in this application, "at least one" means one or more, and "a plurality" means two or more. "and/or" for describing the association relationship of the association object, the representation may have three relationships, for example, "a and/or B" may represent: only a, only B and both a and B are present, wherein a, B may be singular or plural. The character "/" generally indicates that the context-dependent object is an "or" relationship. "at least one of" or the like means any combination of these items, including any combination of single item(s) or plural items(s). For example, at least one (one) of a, b or c may represent: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", wherein a, b, c may be single or plural.

The above embodiments are merely for illustrating the technical solution of the present application, and not for limiting the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the corresponding technical solutions.

Claims

A multiphase voltage step-down circuit, comprising: the device comprises a controller, an auxiliary inductance module, a plurality of coupling windings and at least two-phase voltage reduction circuits; each phase of the step-down circuit comprises a switching circuit and a filter circuit;

the input end of the switching circuit is connected with a power supply, the output end of the switching circuit is connected with the input end of the filter circuit, and the output end of the filter circuit is connected with the output end of the multiphase voltage reduction circuit;

the controller is used for controlling the switch circuit;

the filter circuit comprises an output inductor and at least one output capacitor;

the input end of the output inductor is the input end of the filter circuit, the output end of the output inductor is the output end of the filter circuit, the first end of the at least one output capacitor is connected with the output end of the output inductor, and the second end of the at least one output capacitor is grounded;

the output inductor is coupled with the auxiliary inductor module through the coupling winding;

when the load current of the multiphase voltage reduction circuit is larger than a preset current, the inductance value of the auxiliary inductance module is a first inductance value; when the load current of the multiphase voltage reduction circuit is smaller than or equal to a preset current, the inductance value of the auxiliary inductance module is a second inductance value, and the first inductance value is smaller than the second inductance value.
The multiphase buck circuit according to claim 1, wherein the auxiliary inductor module includes one or more saturated inductors.
The multi-phase buck circuit according to claim 1, wherein the auxiliary inductor module includes a first set of saturated inductors and a second set of saturated inductors, the multi-phase buck circuit including a first set of buck circuits and a second set of buck circuits;

the output inductance of at least one step-down circuit in the first group of step-down circuits is respectively coupled with the first group of auxiliary inductance modules through a coupling winding;

and the output inductors of the step-down circuits in the second group of step-down circuits are respectively coupled with the second group of auxiliary inductance modules through a coupling winding.
The multiphase voltage reduction circuit of claim 1, wherein the auxiliary inductor module comprises at least two auxiliary inductor units connected in series;

each auxiliary inductance unit comprises a switching tube and a first inductance which are connected in parallel;

the controller is used for controlling the switching tube in each auxiliary inductance unit according to the load current.
The multiphase buck circuit according to claim 4, wherein the controller controls the number of closures of the switching tubes in the auxiliary inductor module, which is positively correlated with the magnitude of the load current.
The multiphase buck circuit according to claim 1, wherein the auxiliary inductive module includes at least two auxiliary inductive legs connected in parallel;

each auxiliary inductance branch comprises a switching tube and a second inductance which are connected in series;

the controller is used for controlling the switching tube in each auxiliary inductance branch according to the load current.
The multiphase buck circuit according to claim 6, wherein the controller controls the number of closures of the switching tubes in the auxiliary inductor module, which is positively correlated with the magnitude of the load current.
The multiphase buck circuit according to any of claims 1-7, wherein the controller increases the duty cycle of the control signal of the switching circuit, in particular when the load current increases.
The multiphase voltage reduction circuit of claim 8, wherein the switching circuit comprises a first switching tube and a second switching tube;

the first end of the first switching tube is connected with the input end of the switching circuit, the second end of the first switching tube is connected with the first end of the second switching tube and the output end of the switching circuit, and the second end of the second switching tube is grounded;

The controller is specifically configured to increase the duty ratio of the control signals to the first switching tube and the second switching tube when the load current increases, so that the on time of the first switching tube is prolonged, and the off time of the second switching tube is prolonged.
The multiphase buck circuit according to claim 9, wherein the switching circuit further includes a drive circuit;

the input end of the driving circuit is connected with the controller, and the output end of the driving circuit is connected with the control end of the first switching tube and the control end of the second switching tube;

the driving circuit is used for controlling the first switching tube and the second switching tube according to the control signal output by the controller.
A filter circuit, the filter circuit comprising: the auxiliary inductance module, a plurality of coupling windings, a plurality of output inductances and a plurality of output capacitances;

the first end of each output inductor is an input end of the filter circuit, and the second end of each output inductor is connected with the output end of the filter circuit;

a first end formed by connecting the plurality of output capacitors in parallel is connected with the output end of the filter circuit, and a second end formed by connecting the plurality of output capacitors in parallel is grounded;

Each output inductor is electrically coupled with the auxiliary inductor module through a coupling winding;

when the load current of the filter circuit is larger than the preset current, the inductance value of the auxiliary inductance module is a first inductance value; when the load current of the filter circuit is smaller than or equal to the preset current, the inductance value of the auxiliary inductance module is a second inductance value, and the first inductance value is smaller than the second inductance value.
The filter circuit of claim 11, wherein the auxiliary inductor module comprises a first set of saturated inductors and a second set of saturated inductors, the filter circuit comprising a first set of output inductors and a second set of output inductors;

each output inductor in the first group of output inductors is coupled with the first group of auxiliary inductor modules through a coupling winding respectively;

and each output inductor in the second group of output inductors is respectively coupled with the second group of auxiliary inductor modules through a coupling winding.
The filter circuit of claim 11, wherein the auxiliary inductance module comprises at least two auxiliary inductance units connected in series;

each auxiliary inductance unit comprises a switching tube and a first inductance which are connected in parallel.
The filter circuit of claim 11, wherein the auxiliary inductance module comprises at least two auxiliary inductance branches connected in parallel;

each auxiliary inductance branch comprises a switching tube and a second inductance which are connected in series;
an electronic device, the electronic device comprising a circuit board, the circuit board comprising: a chip and one or more of the multiphase buck circuits of any of claims 1-10;

the output ends of one or more of the multiphase voltage reduction circuits are connected with a power supply pin of the chip;

one or more of the multiphase voltage reduction circuits provides power to the chip.
The filter circuit of claim 15, wherein the circuit board includes a plurality of the multiphase voltage step-down circuits connected in parallel and distributed on different sides of the chip.