EP3914986A1

EP3914986A1 - Integrated power regulator and method

Info

Publication number: EP3914986A1
Application number: EP20767041.5A
Authority: EP
Inventors: Heping Dai; Peng Zou
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Digital Power Technologies Co Ltd
Priority date: 2019-03-06
Filing date: 2020-03-06
Publication date: 2021-12-01
Also published as: CN113424127A; WO2020177757A1; EP3914986A4; CN113424127B

Abstract

An integrated power regulator comprises a plurality of power modules connected in parallel between a positive terminal and a negative terminal of a power source. Each power module of the plurality of power modules comprises a plurality of power conversion cells connected in parallel between the positive terminal and the negative terminal of the power source. A first power conversion cell and a second power conversion cell of the plurality of power conversion cells are configured to operate in two different operating phases. A third power conversion cell and a fourth power conversion cell of the plurality of power conversion cells are configured to operate in a same operating phase.

Description

Integrated Power Regulator and Method

TECHNICAL FIELD

The present disclosure relates to an integrated power regulator and method, and, in particular embodiments, to an M×N-phase integrated power regulator for converting energy in high current applications.

BACKGROUND

As technologies further advance, artificial intelligence (AI) has emerged as an effective alternative to further improve the capability of the computing technology. AI based computing machines exhibit human intelligence such as perceiving, learning, reasoning and solving problems.
The AI based computing machines may be implemented as graphical processing units (GPU) . The graphical processing units allow for performance gains through parallel computations. As the computing power of the graphical processing units has increased, the demand for electrical power has continued to rise.
In order to efficiently power low-voltage, high current loads (e.g., graphical processing units) , a direct-to-chip power architecture has been employed. For example, the input of the direct-to-chip power architecture is a 48-Volt distribution bus. The output of the direct-to-chip power architecture is an IC voltage as low as 0.45 V. The current flowing through the direct-to-chip power architecture is up to 1000 A. In the direct-to-chip power architecture, the inductor of the direct-to-chip power architecture has to endure high current stress.
Integrated voltage regulators can achieve high efficiency for high current applications. A typical integrated voltage regulator comprises a plurality of step-down power converters operating in different phases, thereby achieving fast transient responses, accurate voltage regulation and smaller output voltage ripples. Under a light load operation, the efficiency of the integrated voltage regulator drops significantly due to the switching losses associated with the large number of switching elements operating at a high switching frequency.
In some applications such as portable devices (e.g., smart phones and laptops) , the light load efficiency is very important. As such, it would be desirable to have an integrated regulator capable of achieving high efficiency under a variety of operating conditions.
SUMMARY
These and other problems are generally solved or circumvented, and technical advantages are generally achieved, by preferred embodiments of the present disclosure which provide an integrator power regulator for improving light load efficiency.
In accordance with an embodiment, an apparatus comprises a plurality of power modules connected in parallel between a positive terminal and a negative terminal of a power source. Each power module of the plurality of power modules comprises a plurality of power conversion cells connected in parallel between the positive terminal and the negative terminal of the power source. A first power conversion cell and a second power conversion cell of the plurality of power conversion cells are configured to operate in two different operating phases. A third power conversion cell and a fourth power conversion cell of the plurality of power conversion cells are configured to operate in a same operating phase.
In some embodiments, the plurality of power modules is configured to operate in different operating phases in an interleaved manner, and the plurality of power conversion cells of a same power module is controlled by same gate drive signals. In alternative embodiments, the plurality of power conversion modules is configured to operate in a same operating phase, and the plurality of power conversion cells of a same power module is configured to operate in an interleaved manner.
In some embodiments, a first power conversion module and a second power conversion module are configured to operate in two different operating phases in an interleaved manner, and wherein the first power conversion cell and the second power conversion cell are in the first power conversion module and the second power conversion module respectively. The third power conversion cell and the fourth power conversion cell are in a same power conversion module.
In some embodiments, the first power conversion cell and the second power conversion cell are in a same power conversion module having a plurality power conversion cells operating in a plurality of operating phases. A first power conversion module and a second power conversion module are configured to operate in a same operating phase, and wherein the third power conversion cell and the fourth power conversion cell are in the first power conversion module and the second power conversion module respectively.
In some embodiments, at least two inductors of the plurality of power conversion cells are magnetically coupled to each other. In alternative embodiments, all inductors of the plurality of power conversion cells are magnetically coupled to each other.
In accordance with another embodiment, a method comprises configuring M×N power conversion cells of a power regulator to operate in N operating phases. N and M are predetermined integers greater than or equal to 2. During a light load operation, disabling a plurality of power conversion cells to reduce switching losses while maintaining ripple reduction.
In some embodiments, the power regulator comprises N power conversion modules connected in parallel between a positive terminal and a negative terminal of a power source. Each power conversion module of the N power conversion modules comprises M power conversion cells connected in parallel between the positive terminal and the negative terminal of the power source. The N power conversion modules are configured to operate in the N operating phases in an interleaved manner. The M power conversion cells are controlled by same gate drive signals. The method comprises during the light load operation, disabling one power conversion cell from each power conversion module to reduce the switching losses while maintaining the ripple reduction. The method further comprises during the light load operation, disabling one power conversion module to reduce the switching losses while improving the ripple reduction.
In some embodiments, the power regulator comprises M power conversion modules connected in parallel between a positive terminal and a negative terminal of a power source. Each power conversion module of the M power conversion modules comprises N power conversion cells connected in parallel between the positive terminal and the negative terminal of the power source. The M power modules are configured to operate in a same operating phase, and the N power conversion cells of each power conversion module are configured to operate in in the N operating phases in an interleaved manner. The method comprises during the light load operation, disabling one power conversion module to reduce the switching losses while maintaining the ripple reduction. The method further comprises during the light load operation, disabling one power conversion cell to reduce the switching losses while improving the ripple reduction.
In accordance with yet another embodiment, a method comprises configuring M×N power conversion cells of a power regulator to operate in N operating phases. The power regulator is connected between a power source and a load, and N and M are predetermined integers greater than or equal to 2. During a light load operation, disabling a plurality of power conversion cells to reduce switching losses while maintaining ripple reduction, and during a load transient, dynamically adjusting the N operating phases to improve transient response performance.
In some embodiments, the power regulator comprises N power conversion modules connected in parallel between a positive terminal and a negative terminal of the power source. Each power conversion module of the N power conversion modules comprises M power conversion cells connected in parallel between the positive terminal and the negative terminal of the power source. The N power conversion modules are configured to operate in the N operating phases in an interleaved manner, and the M power conversion cells are controlled by same gate drive signals. A time delay of T/N is placed between gate drive signals of two adjacent power conversion modules. T is a switching cycle of the power regulator. The method comprises during the load transient, dynamically reducing the time delay between two adjacent power conversion modules to improve the transient response performance.
An advantage of an embodiment of the present disclosure is an M×N integrated power regulator for improving the efficiency, reliability and cost of a power conversion system in high current applications.
The foregoing has outlined rather broadly the features and technical advantages of the present disclosure in order that the detailed description of the disclosure that follows may be better understood. Additional features and advantages of the disclosure will be described hereinafter which form the subject of the claims of the disclosure. It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures or processes for carrying out the same purposes of the present disclosure. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the disclosure as set forth in the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present disclosure, and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which:
Figure 1 illustrates a block diagram of an integrated power regulator in accordance with various embodiments of the present disclosure;
Figure 2 illustrates a block diagram of a power conversion module shown in Figure 1 in accordance with various embodiments of the present disclosure;
Figure 3 illustrates a schematic diagram of the power conversion module shown in Figure 2 in accordance with various embodiments of the present disclosure;
Figure 4 illustrates a schematic diagram of another power conversion module in accordance with various embodiments of the present disclosure;
Figure 5 illustrates a schematic diagram of yet another power conversion module in accordance with various embodiments of the present disclosure;
Figure 6 illustrates a first control scheme applied to the integrated power regulator shown in Figure 1 in accordance with various embodiments of the present disclosure;
Figure 7 illustrates a second control scheme applied to the integrated power regulator shown in Figure 1 in accordance with various embodiments of the present disclosure;
Figure 8 illustrates a flow chart of a method for controlling the integrated power regulator shown in Figure 1 in accordance with various embodiments of the present disclosure;
Figure 9 illustrates a flow chart of another method for controlling the integrated power regulator shown in Figure 1 in accordance with various embodiments of the present disclosure;
Figure 10 illustrates a third control scheme applied to the integrated power regulator shown in Figure 1 in accordance with various embodiments of the present disclosure;
Figure 11 illustrates a fourth control scheme applied to the integrated power regulator shown in Figure 1 in accordance with various embodiments of the present disclosure;
Figure 12 illustrates a flow chart of yet another method for controlling the integrated power regulator shown in Figure 1 in accordance with various embodiments of the present disclosure;
Figure 13 illustrates a flow chart of yet another method for controlling the integrated power regulator shown in Figure 1 in accordance with various embodiments of the present disclosure;
Figure 14 illustrates a block diagram of another integrated power regulator in accordance with various embodiments of the present disclosure;
Figure 15 illustrates another integrated power regulator in accordance with various embodiments of the present disclosure;
Figure 16 illustrates a 3×3 integrated power regulator in accordance with various embodiments of the present disclosure; and
Figure 17 illustrates a 4×6 integrated power regulator in accordance with various embodiments of the present disclosure.
Corresponding numerals and symbols in the different figures generally refer to corresponding parts unless otherwise indicated. The figures are drawn to clearly illustrate the relevant aspects of the various embodiments and are not necessarily drawn to scale.
DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS
The making and using of the presently preferred embodiments are discussed in detail below. It should be appreciated, however, that the present disclosure provides many applicable inventive concepts that can be embodied in a wide variety of specific contexts. The specific embodiments discussed are merely illustrative of specific ways to make and use the disclosure, and do not limit the scope of the disclosure.
The present disclosure will be described with respect to preferred embodiments in a specific context, namely an M×N-phase integrated power regulator for converting energy in high current applications. The present disclosure may also be applied, however, to a variety of power regulators. Hereinafter, various embodiments will be explained in detail with reference to the accompanying drawings.
Figure 1 illustrates a block diagram of an integrated power regulator in accordance with various embodiments of the present disclosure. The integrated power regulator 100 is connected between a power source 150 and a load 160. The integrated power regulator 100 is a step-down power conversion system converting energy from the power source 150 to a low voltage and high current load (e.g., load 160) . As shown in Figure 1, the positive terminal of the power source 150 is denoted by VIN+. The negative terminal of the power source 150 is denoted by VIN-. The output of the integrated power regulator 100 is denoted by VOUT.
In some embodiments, the power source 150 is implemented as a 48-Volt direct current distribution bus. Alternatively, the power source 150 may be implemented as other suitable dc power sources such as a solar panel, an energy storage unit, a battery pack, a power converter converting energy from the utility line, a power generator, a renewable power source, any combinations thereof and the like.
The load 160 may be a processor such as a central processing unit (CPU) , a graphics processing unit (GPU) , an application-specific integrated circuit (ASIC) , any combinations thereof and the like. Alternatively, the load 160 may be a plurality of downstream power converters.
The integrated power regulator 100 comprises N power conversion modules connected in parallel between VIN+ and VIN-as shown in Figure 1. N is a predetermined integer greater than or equal to 2. Each power conversion module comprises M power conversion cells. M is a predetermined integer greater than or equal to 2. The detailed structure of the power conversion cells will be described below with respect to Figures 2-3.
As shown in Figure 1, a first power conversion module 111 has a first input terminal connected to VIN+, a second input terminal connected to VIN-and an output terminal connected to VOUT. Likewise, a second power conversion module 112 and an Nth power conversion module 113 has a first input terminal connected to VIN+, a second input terminal connected to VIN-and an output terminal connected to VOUT.
In some embodiments, each of the N power conversion modules comprises M power conversion cells connected in parallel. Each power conversion cell is a step-down power converter such as a buck switching converter. The step-down power converter comprises a high-side switch, a low-side switch and an inductor. In some embodiments, the conducting periods of the high-side switches of the M power conversion cells are equal. The duty cycle D of the integrated power regulator 100 is defined as the conducting period of a high-side switch divided by a switching cycle of the integrated power regulator 100.
It should be noted a capacitor (capacitors) between VIN+ and VIN-can be added into each power conversion cell or power conversion module, and a capacitor (capacitors) between VOUT and VIN-can be added into each power conversion cell or power conversion module to reduce noise and/or improve dynamic response performance.
In operation, the current flowing through the integrated power regulator 100 is distributed evenly among the N power conversion modules shown in Figure 1. Furthermore, the current flowing through each power conversion module is distributed evenly among the inductors of the M power conversion cells. In other words, the average current flowing through the inductor of each power conversion cell is equal to the average load current divided by M×N.
In operation, the N power conversion modules may be configured to operate in N different operating phases. The power conversion cells of each power conversion module are trigged by the same gate drive signals. In some embodiments, a switching cycle is divided into N equal periods. Each period is a time delay between two adjacent operating phases. The N power conversion modules of Figure 1 are configured to operate in N operating phases. Each power conversion module is configured to operate in a corresponding operating phase. The turn-on edges of two adjacent power conversion modules (e.g., power conversion modules 111 and 112) are separated by a time delay of T/N. In alternative embodiments, the N power conversion modules of Figure 1 are configured to operate in N operating phases, each of which is dynamically adjustable. For example, under a load transient, the turn-on edges of two adjacent power conversion modules (e.g., power conversion modules 111 and 112) are separated by a time delay less than T/N. Such a reduced time delay helps to improve the transient response performance of the integrated power regulator 100.
One advantageous feature of having the M×N integrated regulator described above is the integrated power regulator can control M×N power conversion cells through N sets of interleaving control schemes. Such a control system configuration helps to simplify the control system design of the integrated power regulator 100.
In operation, the N power conversion modules may be configured to operate in a same operating phase. The power conversion cells of each power conversion module are configured to operate in M different operating phases. In some embodiments, a switching cycle is divided into M equal periods. Each period is a time delay between two adjacent operating phases. The M power conversion cells of each power conversion module are configured to operate in M operating phases. Each power conversion cell is configured to operate in a corresponding operating phase. The turn-on edges of two adjacent power conversion cells are separated by a time delay of T/M. In alternative embodiments, the M power conversion cells are configured to operate in M operating phases, each of which is dynamically adjustable. For example, under a load transient, the turn-on edges of two adjacent power conversion cells are separated by a time delay less than T/M. Such a reduced time delay helps to improve the transient response performance of the integrated power regulator 100.
In operation, the N power conversion modules may be configured to operate in N different operating phases. The turn-on edges of two adjacent power conversion modules (e.g., power conversion modules 111 and 112) are separated by a time delay of T/N. The power conversion cells of each power conversion module are configured to operate in M different operating phases. The turn-on edges of two adjacent power conversion cells are separated by a time delay of T/ (M·N) . In alternative embodiments, the N power conversion modules of Figure 1 are configured to operate in N operating phases, each of which is dynamically adjustable. Likewise, the M power conversion cells are configured to operate in M operating phases, each of which is dynamically adjustable. Such adjustable time delays helps to improve the transient response performance of the integrated power regulator 100.
Figure 2 illustrates a block diagram of a power conversion module shown in Figure 1 in accordance with various embodiments of the present disclosure. The first power conversion module 111 is used as an example to illustrate the structure of the plurality of power conversion modules shown in Figure 1. The first power conversion module 111 comprises a first power conversion cell 211, a second power conversion cell 212 and an Mth power conversion cell 213. As shown in Figure 2, the first power conversion cell 211 has a first input terminal connected to VIN+, a second input terminal connected to VIN-and an output terminal connected to VOUT. Likewise, a second power conversion cell 212 and the Mth power conversion cell 213 has a first input terminal connected to VIN+, a second input terminal connected to VIN-and an output terminal connected to VOUT. The detailed schematic diagram of the power conversion cells shown in Figure 2 will be described below with respect to Figure 3.
Figure 3 illustrates a schematic diagram of the power conversion module shown in Figure 2 in accordance with various embodiments of the present disclosure. As shown in Figure 3, the first power conversion cell 211, the second power conversion cell 212 and the Mth power converter cell 213 have a similar schematic structure. For simplicity, only the schematic diagram of the first power conversion cell 211 is discussed in detail below.
As shown in Figure 3, the first power conversion cell 211 comprises a high-side switch SH11, a low-side switch SL11 and an inductor L11. The high-side switch SH11 and the low-side switch SL11 are connected in series between VIN+ and VIN-. The inductor L11 is connected between a common node of SH11 and SL11, and VOUT.
In operation, the switches of the power conversion cells of Figure 3 are able to achieve zero voltage switching (ZVS) . In each switching cycle, the current flowing through the inductor of each cell varies from a positive value to zero and further goes negative to achieve ZVS. The ZVS operation helps to achieve higher efficiency and lower electromagnetic interference (EMI) .
In accordance with an embodiment, the switches of Figure 3 (e.g., switches SH11-SH1M and SL11-SL1M) may be metal oxide semiconductor field-effect transistor (MOSFET) devices. Alternatively, the switching element can be any controllable switches such as insulated gate bipolar transistor (IGBT) devices, integrated gate commutated thyristor (IGCT) devices, gate turn-off thyristor (GTO) devices, silicon controlled rectifier (SCR) devices, junction gate field-effect transistor (JFET) devices, MOS controlled thyristor (MCT) devices and the like. Furthermore, the switches may be implemented as gallium nitride (GaN) based semiconductor devices, silicon carbide (SiC) based semiconductor devices and the like.
It should be noted while Figure 3 shows the switches SH11-SH1M and SL11-SL1M are implemented as single n-type transistors, a person skilled in the art would recognize there may be many variations, modifications and alternatives. For example, depending on different applications and design needs, at least some of the switches SH11-SH1M and SL11-SL1M may be implemented as p-type transistors. Furthermore, each switch shown in Figure 3 may be implemented as a plurality of switches connected in parallel. Moreover, a capacitor may be connected in parallel with one switch to achieve zero voltage switching (ZVS) /zero current switching (ZCS) .
Figure 4 illustrates a schematic diagram of another power conversion module in accordance with various embodiments of the present disclosure. The power conversion module shown in Figure 4 is similar to the power conversion module shown in Figure 3 except that at least two inductors (e.g., L11 and L12) of the M power conversion cells are magnetically coupled to each other.
It should be noted that the magnetic coupling used in Figure 4 is selected purely for demonstration purposes and are not intended to limit the various embodiments of the present disclosure to any particular magnetic coupling configurations. One of ordinary skill in the art would recognize many variations, alternatives, and modifications. For example, the at least two inductors of the M power conversion cells may be magnetically coupled to one or more inductors of an adjacent power module, thereby reducing the size of the magnetic components. Furthermore, the coupled inductors of the N power modules may be magnetically coupled to each other.
Figure 5 illustrates a schematic diagram of yet another power conversion module in accordance with various embodiments of the present disclosure. The power conversion module shown in Figure 5 is similar to the power conversion module shown in Figure 4 except that all inductors (e.g., L11-L1M) of the M power conversion cells are magnetically coupled to each other.
It should be noted that the magnetic coupling used in Figure 5 is selected purely for demonstration purposes and are not intended to limit the various embodiments of the present disclosure to any particular magnetic coupling configurations. One of ordinary skill in the art would recognize many variations, alternatives, and modifications. For example, the M inductors of the M power conversion cells may be magnetically coupled to one or more inductors of an adjacent power module, thereby reducing the size of the magnetic components. Furthermore, the coupled inductors of the N power modules may be magnetically coupled to each other.
Figure 6 illustrates a first control scheme applied to the integrated power regulator shown in Figure 1 in accordance with various embodiments of the present disclosure. In some embodiments, the N power conversion modules of the integrated power regulator are configured to operate in N different operating phases. Each power conversion module comprises M power conversion cells. The M power conversion cells of a same power module are configured to operate in a same operating phase. In other words, the leading edges of the M power conversion cells are triggered simultaneously or almost simultaneously. For example, the high-side switches of the M power conversion cells are controlled by a same high-side gate drive signal. Likewise, the low-side switches of the M power conversion cells are controlled by a same low-side gate drive signal.
In response to the N different operating phases, a switching cycle of the integrated power regulator 100 is divided into N equal portions. The leading edge of the high-side switches of the first power conversion module 111 is trigged at the beginning of the switching period. The leading edge of the high-side switches of the second power conversion module 112 is trigged at T/N as shown in Figure 6. The leading edge of the high-side switches of the Nth power conversion module 113 is trigged at T· (N-1) /N. In other words, there is a time delay or a phase shift between two adjacent power conversion modules. The time delay or the phase shift is equal to T/N.
Figure 7 illustrates a second control scheme applied to the integrated power regulator shown in Figure 1 in accordance with various embodiments of the present disclosure. The system configuration of the integrated power regulator shown in Figure 7 is similar to that shown in Figure 6 except that the time delay between two adjacent power conversion modules is dynamically adjustable.
In some embodiments, the N power conversion modules of the integrated power regulator are configured to operate in N different operating phases. In response to the N different operating phases, a switching cycle of the integrated power regulator is divided into N portions. The leading edge of the high-side switches of the first power conversion module 111 is trigged at the beginning of the switching period. The leading edge of the high-side switches of the second power conversion module 112 is trigged at a·T, where a is a predetermined parameter in a range from 0 to 1. The leading edge of the high-side switches of the Nth power conversion module 113 is trigged at b·T, where b is predetermined parameter in a range from 0 to 1. In some embodiments, b is greater than a.
During a load transient, the time delay (e.g., a·T) between two adjacent power conversion modules (e.g., power conversion modules 111 and 112) is dynamically adjustable. For example, at a time instant between 0 and a·T, a load transient is applied to the integrated power regulator 100. In order to achieve better load transient response performance, the high-side switches of the second power conversion module 112 are turned on immediately. In other words, the time delay between the first power conversion module 111 and the second power conversion module 112 is reduced so as to trigger the turn-on of the high-side switches of the second power conversion module 112 immediately after detecting the load transient.
Figure 8 illustrates a flow chart of a method for controlling the integrated power regulator shown in Figure 1 in accordance with various embodiments of the present disclosure. This flowchart shown in Figure 8 is merely an example, which should not unduly limit the scope of the claims. One of ordinary skill in the art would recognize many variations, alternatives, and modifications. For example, various steps illustrated in Figure 8 may be added, removed, replaced, rearranged and repeated.
Referring back to Figure 1, the integrated power regulator 100 comprises N power conversion modules connected in parallel between a positive terminal and a negative terminal of a power source. Each power module of the N power modules comprises M power conversion cells connected in parallel between the positive terminal and the negative terminal of the power source. In some embodiments, the N power modules are configured to operate in the N operating phases in an interleaved manner, and the M power conversion cells are controlled by same gate drive signals.
At step 802, a first sensing device is configured to detect an output voltage of the integrated power regulator. A second sensing device is configured to detect a load current of the integrated power regulator.
At step 804, in response to a light load operation, one power conversion cell of each power module is disabled. As a result of disabling one power conversion cell from each power module, the switching losses of the integrated power regulator is reduced accordingly.
It should be noted that disabling one or a plurality of power conversion cells to improve the light load efficiency may be alternatively referred to as cell shedding. The cell shedding technique helps to boost the light load efficiency through turning off one or a plurality of power conversion cells. By turning off the plurality of power conversion cells, the power consumption of switching the MOSFETs is saved for every power conversion cell that is disabled.
It should further be noted that the control method described at step 804 may be applied again to disable additional power conversion cells. After the number of the power conversion cells is reduced from M to 1, a power conversion module (having one active power conversion cell and M-1 inactive power conversion cells) may be disabled to further reduce the switching losses. As a result, the total number of power conversion modules is reduced from N to N-1. After the load further drops, additional power conversion modules are disabled accordingly. At an ultra-light load operation, there may be only one active power conversion cell converting energy between the power source and the load.
At step 806, after the integrated power regulator leaves the light load operation, the inactive power conversion cells are enabled to reduce conduction losses.
Figure 9 illustrates a flow chart of another method for controlling the integrated power regulator shown in Figure 1 in accordance with various embodiments of the present disclosure. This flowchart shown in Figure 9 is merely an example, which should not unduly limit the scope of the claims. One of ordinary skill in the art would recognize many variations, alternatives, and modifications. For example, various steps illustrated in Figure 9 may be added, removed, replaced, rearranged and repeated.
At step 902, a first sensing device is configured to detect an output voltage of the integrated power regulator. A second sensing device is configured to detect a load current of the integrated power regulator.
At step 904, in response to a light load operation, one power conversion module is disabled when the integrated power regulator operates at a particular duty cycle. As a result of disabling one power module, the switching losses of the integrated power regulator is reduced accordingly. For example, the integrated power regulator is a 3×3 integrated power regulator. At a particular input/output voltage ratio, the integrated power regulator operates a 50%duty cycle. When the integrated power regulator enters into the light load operation, a power conversion module is disabled. As a result of disabling one power conversion module, the total number of the operating phases is reduced from 3 to 2. For a 50%duty cycle, an integrated power regulator having two operating phases in an interleaved manner is able to fully cancel the output current ripple. As such, during the light load operation, a power conversion module is disabled first. As the load further drops, the control method described above with respect to Figure 8 is applicable to the remaining two power conversion modules.
At step 906, after the integrated power regulator leaves the light load operation, the inactive power conversion module is enabled to reduce conduction losses.
Figure 10 illustrates a third control scheme applied to the integrated power regulator shown in Figure 1 in accordance with various embodiments of the present disclosure. In some embodiments, the N power conversion modules of the integrated power regulator are configured to operate in a same operating phase. In other words, the leading edges of the first power conversion cells of the N power conversion modules are triggered simultaneously or almost simultaneously. For example, the high-side switches the first power conversion cells of the N power conversion modules are controlled by a same high-side gate drive signal. The low-side switches of the first power conversion cells of the N power conversion modules are controlled by a same low-side gate drive signal.
Each power conversion module comprises M power conversion cells. The M power conversion cells of a same power module are configured to operate in M different operating phases. In response to the M different operating phases, a switching cycle of the integrated power regulator is divided into M equal portions. The leading edge of the high-side switch of the first power conversion cell 211 is trigged at the beginning of the switching period. The leading edge of the high-side switch of the second power conversion cell 212 is trigged at T/M. The leading edge of the high-side switch of the Mth power conversion cell 213 is trigged at T· (M-1) /M.
Figure 11 illustrates a fourth control scheme applied to the integrated power regulator shown in Figure 1 in accordance with various embodiments of the present disclosure. The system configuration of the integrated power regulator shown in Figure 11 is similar to that shown in Figure 10 except that the time delay between two adjacent power conversion cells is dynamically adjustable.
In some embodiments, the M power conversion cells of the first power conversion module 111 are configured to operate in M different operating phases. In response to the M different operating phases, a switching cycle of the integrated power regulator is divided into M portions. The leading edge of the high-side switches of the first power conversion cell 211 is trigged at the beginning of the switching period. The leading edge of the high-side switches of the second power conversion cell 212 is trigged at c·T, where c is predetermined parameter in a range from 0 to 1. The leading edge of the high-side switches of the Mth power conversion cell 213 is trigged at d·T, where d is predetermined parameter in a range from 0 to 1. In some embodiments, d is greater than c.
During a load transient, the time delay (e.g., c·T) between two adjacent power conversion cells (e.g., power conversion cells 211 and 212) is dynamically adjustable. For example, at a time instant between 0 and c·T, a load transient is applied to the integrated power regulator 100. In order to achieve better load transient response performance, the high-side switch of the second power conversion cell 212 is turned on immediately. In other words, the time delay between the first power conversion cell 211 and the second power conversion cell 212 is reduced so as to trigger the turn-on of the high-side switch of the second power conversion cell 212 immediately after detecting the load transient.
Figure 12 illustrates a flow chart of yet another method for controlling the integrated power regulator shown in Figure 1 in accordance with various embodiments of the present disclosure. This flowchart shown in Figure 12 is merely an example, which should not unduly limit the scope of the claims. One of ordinary skill in the art would recognize many variations, alternatives, and modifications. For example, various steps illustrated in Figure 12 may be added, removed, replaced, rearranged and repeated.
Referring back to Figure 1, the integrated power regulator 100 comprises N power conversion modules connected in parallel between a positive terminal and a negative terminal of a power source. Each power module of the N power modules comprises M power conversion cells connected in parallel between the positive terminal and the negative terminal of the power source. In some embodiments, the N power modules are configured to operate in a same operating phase, and the M power conversion cells operate in M different operating phases in an interleaved manner.
At step 1202, a first sensing device is configured to detect an output voltage of the integrated power regulator. A second sensing device is configured to detect a load current of the integrated power regulator.
At step 1204, in response to a light load operation, one power conversion module is disabled. As a result of disabling one power conversion module, the switching losses of the integrated power regulator is reduced accordingly. The disabled power conversion module has no impact on the interleaving operation of the integrated power regulator.
It should be noted that the control method described at step 1204 may be applied again to disable additional power conversion modules. After the number of the power conversion modules is reduced from N to 1, a power conversion cell of the remaining power conversion module is disabled to further reduce the switching losses. As a result, the total number of power conversion cells is reduced from M to M-1. After the load further drops, additional power conversion cells are disabled accordingly. At an ultra-light load operation, there may be only one active power conversion cell converting energy from the power source to the load.
At step 1206, after the integrated power regulator leaves the light load operation, the inactive power conversion cells and/or power conversion modules are enabled to reduce conduction losses.
Figure 13 illustrates a flow chart of yet another method for controlling the integrated power regulator shown in Figure 1 in accordance with various embodiments of the present disclosure. This flowchart shown in Figure 13 is merely an example, which should not unduly limit the scope of the claims. One of ordinary skill in the art would recognize many variations, alternatives, and modifications. For example, various steps illustrated in Figure 13 may be added, removed, replaced, rearranged and repeated.
At step 1302, a first sensing device is configured to detect an output voltage of the integrated power regulator. A second sensing device is configured to detect a load current of the integrated power regulator.
At step 1304, in response to a light load operation, one power conversion cell is disabled when the integrated power regulator operates at a particular duty cycle. As a result of disabling one power conversion cell, the switching losses of the integrated power regulator is reduced accordingly. For example, the integrated power regulator is a 3×3 integrated power regulator. The three power conversion modules operate in a same phase. The three power conversion cells of each power conversion module operate in three different phases in an interleaved manner. At a particular input/output voltage ratio, the integrated power regulator operates a 50%duty cycle. When the integrated power regulator enters into the light load operation, one power conversion cell of each power conversion module is disabled. As a result of disabling one power conversion module, the total number of the operating phases of each power conversion module is reduced from 3 to 2. For a 50%duty cycle, an integrated power regulator having two operating phases in an interleaved manner is able to fully cancel the output current ripple. As such, during the light load operation, a power conversion cell is disabled first. By using this control scheme, the ripple cancellation can be achieved.
At step 1306, after the integrated power regulator leaves the light load operation, the inactive power conversion cells are enabled to reduce conduction losses.
Figure 14 illustrates a block diagram of another integrated power regulator in accordance with various embodiments of the present disclosure. The power conversion module shown in Figure 14 is similar to the power conversion module shown in Figure 1 except that the number of power conversion cells in each power module is not fixed. In some embodiments, the first power conversion module 111 comprises M power conversion cells. The second power conversion module 112 comprises 2·M power conversion cells. The Nth power conversion module 113 comprises N·M power conversion cells. The number of power conversion cells in each power conversion module shown in Figure 14 is merely an example. Depending on different applications and design needs, the number of power conversion cells in each power conversion module may vary accordingly. It should be noted that the control schemes described above with respect to Figures 1-13 are applicable to the integrated power regulator shown in Figure 14.
Figure 15 illustrates another integrated power regulator in accordance with various embodiments of the present disclosure. The integrated power regulator shown in Figure 15 is similar to the integrated power regulator shown in Figures 1-3 except that both the power conversion modules and the power conversion cells operate in an interleaved manner.
As shown in Figure 15, both the power conversion modules and the power conversion cells are interleaved. There is a time delay of T/N between two adjacent power conversion modules. Likewise, there is a time delay of T/ (N·M) between two adjacent power conversion cells.
Figure 16 illustrates a 3×3 integrated power regulator in accordance with various embodiments of the present disclosure. The integrated power regulator shown in Figure 16 is similar to the integrated power regulator shown in Figures 1-3, and hence is not discussed again to avoid repetition.
In some embodiments, the three power conversion modules 111, 112 and 113 operate in three different operating phases. Each power conversion module (e.g., power conversion module 111) comprises three power conversion cells. As shown in Figure 16, the first power conversion module 111 comprises a first power conversion cell 211, a second power conversion cell 212 and a third power conversion cell 213. The three power conversion cells of the same power conversion module operate in a same operating phase. In other words, the high-side switches of the three power conversion cells are controlled by a same high-side gate drive signal. Likewise, the low-side switches of the three power conversion cells are controlled by a same low-side gate drive signal.
Table 1 shows comparison results between a conventional 3-phase integrated regulator and the 3×3 integrated power regulator shown in Figure 16. In some embodiments, both the conventional 3-phase integrated regulator and the 3×3 integrated power regulator operate at a duty cycle of 50%. The three power conversion modules of the conventional 3-phase integrated regulator operate in three different phases in an interleaved manner. Each power conversion module of the conventional 3-phase integrated regulator is considered as a power conversion cell for comparison purposes. The three power conversion modules 111, 112 and 113 of the 3×3 integrated power regulator operate in three different operating phases. The three power conversion cells of each power conversion module of the 3×3 integrated power regulator operate in a same operating phase.
It should be noted that the interleaved power conversion modules are able to adjust the phase shift to obtain an appropriate system configuration after one or more power modules are disabled. For example, after one power conversion module is disabled, the remaining power conversion modules are able to adjust the phase shift so as to achieve a 2-phase interleaved operation. At a 50%duty cycle, such a 2-phase interleaved operation helps to cancel the output current/voltage ripples. Likewise, the interleaved power conversion cells are able to adjust the phase shift to obtain an appropriate system configuration after one or more power conversion cells are disabled.
Table 1
As shown in Table 1, the inductance of the power conversion cell of the 3×3 integrated power regulator is three times greater than the inductance of the power conversion cell of the conventional 3-phase integrated regulator so that the equivalent inductance per module or per phase is the same for the conventional 3-phase integrated regulator and the 3-module 3×3 integrated power regulator.
In a normal operation mode, the current ripple of each power conversion module of the conventional 3-phase integrated regulator is as large as the current ripple of each power conversion module of the 3×3 integrated power regulator. The current ripple of each power conversion cell of the 3×3 integrated power regulator is one-third as large as the current ripple of the power conversion cell of the conventional 3-phase integrated regulator. The total output current ripple of the conventional 3-phase integrated regulator is as large as the total output current ripple of the 3×3 integrated power regulator.
In a light load operation mode, in order to reduce switching losses, one power conversion cell is dropped from each power conversion module of the 3×3 integrated power regulator. The 3×3 integrated power regulator still maintains the three-phase interleaving operation. For the conventional 3-phase integrated regulator, one power conversion module is dropped to reduce the switching losses. As shown in Table 1, the current ripple per power conversion module of the 3×3 integrated power regulator is equal to 2· (1-D) ·Vo/ (fs·3·L) , where fs and Vo are the switching frequency and the output voltage of the 3×3 integrated power regulator respectively. The current ripple equation above can be simplified as Vo/ (3·fs·L) as shown in Table 1. The total output current ripple of the 3×3 integrated power regulator is equal to Vo/ (9·fs·L) due to the interleaving operation. In contrast, the conventional 3-phase integrated regulator becomes a 2-phase integrated regulator after dropping one power conversion module. At a 50%duty cycle, the total output current ripple of the 2-phase integrated regulator is equal to zero as shown in Table 1.
In the light load operation mode, in order to further reduce the switching losses, two power conversion cells are dropped from each power conversion module of the 3×3 integrated power regulator. The 3×3 integrated power regulator still maintains the three-phase interleaving operation. For the conventional 3-phase integrated regulator, two power conversion modules are dropped to reduce the switching losses. As shown in Table 1, the current ripple per power conversion module of the 3×3 integrated power regulator is equal to Vo/ (6·fs·L) as shown in Table 1. The total output current ripple of the 3×3 integrated power regulator is equal to Vo/ (18·fs·L) due to the interleaving operation. In contrast, the conventional 3-phase integrated regulator becomes a single phase integrated regulator after dropping two power conversion modules. At a 50%duty cycle, the total output current ripple of the single phase integrated regulator is equal to Vo/ (2·fs·L) as shown in Table 1.
As shown in Table 1, the total output current ripple of the 3×3 integrated power regulator is significantly reduced after dropping one or more power conversion cells. If the power conversion system requires same output current or voltage ripples under different operating conditions, the switching frequency of the 3×3 integrated power regulator can be reduced accordingly after the power conversion cells have been dropped. The reduced switching frequency can further reduce the switching power losses of the 3×3 integrated power regulator.
One advantageous feature shown in Table 1 is the power conversion cells in each power conversion module can be dropped without changing the interleaved operation to achieve power loss reduction. As a result, the integrated power regulator can achieve both power saving in the light load operation and output voltage ripple cancellation/reduction.
Table 2 shows the current ripples of the 3×3 integrated power regulator after one or more power conversion modules or power conversion cells have been dropped.
Table 2
The current ripples of the normal operation shown in Table 2 are similar to those shown in Table 1, and hence are not discussed again herein. In response to a light load operation mode, one power conversion module is dropped. As a result of dropping one power conversion module, the 3×3 integrated power regulator becomes a 2-phase integrated regulator. At a 50%duty cycle, the total output current ripple of the 3×3 integrated power regulator (2-phase integrated regulator) is equal to zero as shown in Table 2.
In order to further reduce the switching losses, one power conversion cell is dropped from each remaining active power conversion module of the 3×3 integrated power regulator. The total output current ripple of the 3×3 integrated power regulator (two active power conversion modules, each of which has two power conversion cells) is equal to zero as shown in Table 2. Furthermore, two power conversion cells are dropped from each remaining active power conversion module of the 3×3 integrated power regulator. The total output current ripple of the 3×3 integrated power regulator (two active power conversion modules, each of which has one power conversion cell) is equal to zero as shown in Table 2. Moreover, one more power conversion module is dropped to reduce the switching losses. The 3×3 integrated power regulator becomes a single phase integrated regulator. The remaining power conversion module comprises one active power conversion cell. The total output current ripple of the 3×3 integrated power regulator is equal to Vo/ (6·fs·L) as shown in Table 2.
Figure 17 illustrates a 4×6 integrated power regulator in accordance with various embodiments of the present disclosure. The integrated power regulator shown in Figure 17 is similar to the integrated power regulator shown in Figures 1-3, and hence is not discussed again to avoid repetition.
In some embodiments, the six power conversion modules 111-116 operate in six different operating phases. Each power conversion module (e.g., power conversion module 111) comprises four power conversion cells. As shown in Figure 17, the first power conversion module 111 comprises power conversion cells 211-214. The four power conversion cells of the same power conversion module operate in a same operating phase. In other words, the high-side switches of the four power conversion cells are controlled by a same high-side gate drive signal. Likewise, the low-side switches of the four power conversion cells are controlled by a same low-side gate drive signal.
Table 3 shows comparison results between a conventional 6-phase integrated regulator and the 4×6 integrated power regulator shown in Figure 17. In some embodiments, both the conventional 6-phase integrated regulator and the 4×6 integrated power regulator operate at a duty cycle of 50%. The six power conversion modules of the conventional 6-phase integrated regulator operate in six different phases in an interleaved manner. Each power conversion module of the conventional 6-phase integrated regulator is considered as a power conversion cell for comparison purposes. The six power conversion modules 111-116 of the 4×6 integrated power regulator operate in six different operating phases. The four power conversion cells of each power conversion module of the 4×6 integrated power regulator operate in a same operating phase.
It should be noted that the interleaved power conversion modules are able to adjust the phase shift to obtain an appropriate system configuration after one or more power modules are disabled. For example, after one power conversion module is disabled, the remaining power conversion modules are able to adjust the phase shift so as to achieve a 5-phase interleaved operation. Likewise, the interleaved power conversion cells are able to adjust the phase shift to obtain an appropriate system configuration after one or more power conversion cells are disabled.
Table 3
As shown in Table 3, the inductance of the power conversion cell of the 4×6 integrated power regulator is four times greater than the inductance of the power conversion cell of the conventional 6-phase integrated regulator to have the same equivalent inductor per module.
In a normal operation mode, the current ripple of each power conversion module of the conventional 6-phase integrated regulator is as large as the current ripple of each power conversion module of the 4×6 integrated power regulator. The current ripple of each power conversion cell of the 4×6 integrated power regulator is one-fourth as large as the current ripple of the power conversion cell of the conventional 6-phase integrated regulator. Both the 4×6 integrated power regulator and the conventional 6-phase integrated regulator can achieve ripple cancellation.
In a light load operation mode, in order to reduce switching losses, one power conversion cell is dropped from each power conversion module of the 4×6 integrated power regulator. The 4×6 integrated power regulator still maintains the six-phase interleaving operation. For the conventional 6-phase integrated regulator, one power conversion module is dropped to reduce the switching losses. As shown in Table 3, the current ripple per power conversion module of the 4×6 integrated power regulator is equal to 3·Vo/ (8·fs·L) . The total output current ripple of the 4×6 integrated power regulator is equal to zero due to the ripple cancellation described above. In contrast, the conventional 6-phase integrated regulator becomes a 5-phase integrated regulator after dropping one power conversion module. The current ripple of the conventional 6-phase integrated regulator is equal to Vo/ (10·fs·L) as shown in Table 3.
In the light load operation mode, in order to further reduce the switching losses, two power conversion cells are dropped from each power conversion module of the 4×6 integrated power regulator. The 4×6 integrated power regulator still maintains the six-phase interleaving operation. For the conventional 6-phase integrated regulator, two power conversion modules are dropped to reduce the switching losses. As shown in Table 3, the current ripple per power conversion module of the 4×6 integrated power regulator is equal to Vo/ (4·fs·L) as shown in Table 3. The total output current ripple of the 4×6 integrated power regulator is equal to zero due to the ripple cancellation described above. In contrast, the conventional 6-phase integrated regulator becomes a 4-phase integrated regulator after dropping two power conversion modules. At a 50%duty cycle, the total output current ripple of the conventional 6-phase integrated regulator is equal to zero as shown in Table 3.
Furthermore, three power conversion cells are dropped from each power conversion module of the 4×6 integrated power regulator. The 4×6 integrated power regulator still maintains the six-phase interleaving operation. For the conventional 6-phase integrated regulator, three power conversion modules are dropped to reduce the switching losses. As shown in Table 3, the current ripple per power conversion module of the 4×6 integrated power regulator is equal to Vo/ (8·fs·L) as shown in Table 3. The total output current ripple of the 4×6 integrated power regulator is equal to zero due to the ripple cancellation described above. In contrast, the conventional 6-phase integrated regulator becomes a 3-phase integrated regulator after dropping three power conversion modules. The total output current ripple of the conventional 6-phase integrated regulator is equal to Vo/ (6·fs·L) as shown in Table 3.
Although embodiments of the present disclosure and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the disclosure as defined by the appended claims.
Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one of ordinary skill in the art will readily appreciate from the disclosure of the present disclosure, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed, that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized according to the present disclosure. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps. The specification and drawings are, accordingly, to be regarded simply as an illustration of the disclosure as defined by the appended claims, and are contemplated to cover any and all modifications, variations, combinations or equivalents that fall within the scope of the present disclosure.

Claims

An apparatus comprising:

a plurality of power conversion modules connected in parallel between a positive terminal and a negative terminal of a power source, each power conversion module of the plurality of power conversion modules comprises a plurality of power conversion cells connected in parallel between the positive terminal and the negative terminal of the power source, and wherein:

a first power conversion cell and a second power conversion cell are configured to operate in two different operating phases; and

a third power conversion cell and a fourth power conversion cell are configured to operate in a same operating phase.
The apparatus of claim 1, wherein:

the plurality of power modules is configured to operate in different operating phases in an interleaved manner; and

the plurality of power conversion cells of a same power module is controlled by same gate drive signals.
The apparatus of claim 1, wherein:

the plurality of power conversion modules is configured to operate in a same operating phase; and

the plurality of power conversion cells of a same power module is configured to operate in an interleaved manner.
The apparatus of any one of claims 1-3, wherein:

each of the plurality of power conversion cells is implemented as a step-down power converter comprising a high-side switch, a low-side switch and an inductor, and wherein the high-side switch and the low-side switch are connected in series between the positive terminal and the negative terminal of the power source, and the inductor is connected to a common node of the high-side switch and the low-side switch.
The apparatus of any one of claims 1-4, wherein:

a first power conversion module and a second power conversion module are configured to operate in two different operating phases in an interleaved manner, and wherein the first power conversion cell and the second power conversion cell are in the first power conversion module and the second power conversion module respectively; and

the third power conversion cell and the fourth power conversion cell are in a same power conversion module.
The apparatus of any one of claims 1-4, wherein:

the first power conversion cell and the second power conversion cell are in a same power conversion module having a plurality power conversion cells operating in a plurality of operating phases; and

a first power conversion module and a second power conversion module are configured to operate in a same operating phase, and wherein the third power conversion cell and the fourth power conversion cell are in the first power conversion module and the second power conversion module respectively.
The apparatus of any one of claims 1-6, wherein:

each of the plurality of power conversion cells comprises an inductor, and wherein at least two inductors of the plurality of power conversion cells are magnetically coupled to each other.
The apparatus of any one of claims 1-6, wherein:

each of the plurality of power conversion cells comprises an inductor, and wherein all inductors of the plurality of power conversion cells are magnetically coupled to each other.
The apparatus of any one of claims 1-6, wherein:

a first power conversion module comprises a plurality of first power conversion cells, each of which comprises an inductor; and

a second power conversion module comprises a plurality of second power conversion cells, each of which comprises an inductor, and wherein at least one inductor of the first power conversion module is magnetically coupled to at least one inductor of the second power conversion module.
The apparatus of any one of claims 1-6, wherein:

a first power conversion module comprises a plurality of first power conversion cells, each of which comprises an inductor; and

a second power conversion module comprises a plurality of second power conversion cells, each of which comprises an inductor, and wherein all inductors of the first power conversion module are magnetically coupled to all inductors of the second power conversion module.
A method comprising:

configuring M×N power conversion cells of a power regulator to operate in N operating phases, wherein N and M are predetermined integers greater than or equal to 2; and

during a light load operation, disabling a plurality of power conversion cells to reduce switching losses while maintaining ripple reduction.
The method of claim 11, wherein:

the power regulator comprises N power conversion modules connected in parallel between a positive terminal and a negative terminal of a power source, and wherein each power conversion module of the N power conversion modules comprises M power conversion cells connected in parallel between the positive terminal and the negative terminal of the power source, and wherein:

the N power conversion modules are configured to operate in the N operating phases in an interleaved manner; and

the M power conversion cells are controlled by same gate drive signals.
The method of any one of claims 11-12, further comprising:

during the light load operation, disabling one power conversion cell from each power conversion module to reduce the switching losses while maintaining the ripple reduction.
The method of any one of claims 11-12, further comprising:

during the light load operation, disabling one power conversion module to reduce the switching losses while improving the ripple reduction.
The method of claim 11, wherein:

the power regulator comprises M power conversion modules connected in parallel between a positive terminal and a negative terminal of a power source, and wherein each power conversion module of the M power conversion modules comprises N power conversion cells connected in parallel between the positive terminal and the negative terminal of the power source, and wherein the M power modules are configured to operate in a same operating phase, and the N power conversion cells of each power conversion module are configured to operate in in the N operating phases in an interleaved manner.
The method of claim 15, further comprising:

during the light load operation, disabling one power conversion module to reduce the switching losses while maintaining the ripple reduction.
The method of claim 15, further comprising:

during the light load operation, disabling one power conversion cell to reduce the switching losses while improving the ripple reduction.
A method comprising:

configuring M×N power conversion cells of a power regulator to operate in N operating phases, wherein the power regulator is connected between a power source and a load, and N and M are predetermined integers greater than or equal to 2;

during a light load operation, disabling a plurality of power conversion cells to reduce switching losses while maintaining ripple reduction; and

during a load transient, dynamically adjusting the N operating phases to improve transient response performance.
The method of claim 18, wherein:

the power regulator comprises N power conversion modules connected in parallel between a positive terminal and a negative terminal of the power source, and wherein each power conversion module of the N power conversion modules comprises M power conversion cells connected in parallel between the positive terminal and the negative terminal of the power source, and wherein the N power conversion modules are configured to operate in the N operating phases in an interleaved manner, and the M power conversion cells are controlled by same gate drive signals, and wherein a time delay of T/N is placed between gate drive signals of two adjacent power conversion modules, and wherein T is a switching cycle of the power regulator.
The method of any one of claims 18-19, further comprising:

during the load transient, dynamically reducing the time delay between two adjacent power conversion modules to improve the transient response performance.