Multi-phase switching converter, and controller and control method thereof

Abstract

The invention discloses a multiphase switching converter, and a controller and a control method thereof. The controller comprises a comparison circuit, a duration adjusting unit and a switch control unit. The comparison circuit generates a comparison signal according to the output voltage and a reference signal. The duration adjusting unit provides an adjusted conduction duration signal according to the initial conduction duration signal and the comparison signal, so as to adjust the conduction duration of a plurality of switching circuits in the multiphase switching converter according to the period of the comparison signal on the basis of the initial conduction duration. The switch control unit controls the plurality of switch circuits to be sequentially switched on according to the comparison signal, and controls the switch-off time of the plurality of switch circuits according to the adjusted switch-on duration signal. The multiphase switching converter adjusts the conduction duration of a plurality of switching circuits in real time according to the period of the comparison signal, the control is more flexible, the power supply capability when the switching frequency is increased is ensured, and the response speed is higher.

Description

Technical Field

[0001] The present invention relates to an electronic circuit, and more particularly to a multi-phase switching converter, a controller and a control method thereof. Background Art

[0002] In recent years, with the emergence of high-performance processors, power supply systems with smaller output voltages and larger output currents are required, and the requirements for their thermal performance and transient response performance are becoming increasingly higher. Multiphase switching converters have been widely used due to their superior performance. Multiphase switching converters include multiple switching circuits, each of which is one phase, and the outputs of multiple switching circuits are coupled together to provide output voltages to loads.

[0003] In order to achieve fast load response, constant on-time control is increasingly used in multi-phase switching converters. However, with the increase in the number of phases and switching frequency of multi-phase switching converters, how to set a stable and reliable constant on-time control of multi-phase switching converters has become a new challenge. Summary of the invention

[0004] Therefore, the purpose of the present invention is to solve the above-mentioned technical problems in the prior art and to provide a multi-phase switching converter, a controller and a control method thereof.

[0005] According to an embodiment of the present invention, a controller for a multi-phase switching converter is proposed, comprising: a comparison circuit, which generates a comparison signal according to the output voltage of the multi-phase switching converter and a reference signal; an initial duration generating unit, which provides an initial on-time signal to control the initial on-time of each switching circuit in the multi-phase switching converter; a duration adjusting unit, which provides an adjusted on-time signal according to the initial on-time signal and the comparison signal, so as to adjust the on-time of multiple switching circuits in the multi-phase switching converter according to the period of the comparison signal on the basis of the initial on-time; and a switch control unit, which provides multiple pulse width modulation signals according to the comparison signal and the adjusted on-time signal to control the multiple switching circuits in the multi-phase switching converter, wherein the switch control unit controls the multiple switching circuits to be turned on in sequence according to the comparison signal, and controls the turn-off moments of the multiple switching circuits in the multi-phase switching converter according to the adjusted on-time signal.

[0006] According to an embodiment of the present invention, a controller for a multi-phase switching converter is also proposed, comprising: a comparison circuit, which generates a comparison signal according to the output voltage of the multi-phase switching converter and a reference signal; and a programmable circuit, which generates a plurality of pulse width modulation signals according to the comparison signal to control a plurality of switching circuits in the multi-phase switching converter, wherein the programmable control circuit controls the plurality of switching circuits to be turned on in sequence according to the comparison signal, and controls the turn-off moments of the plurality of switching circuits according to the cycle and initial on-time of the comparison signal; wherein when the cycle of the comparison signal is less than the adjustment cycle, the programmable circuit controls the on-time of the corresponding switching circuit to decrease in response to an increase in the cycle of the comparison signal, and to increase in response to a decrease in the comparison cycle; and when the cycle of the comparison signal is greater than the adjustment cycle, the programmable circuit controls the on-time of the corresponding switching circuit to be equal to the initial on-time.

[0007] According to an embodiment of the present invention, a multi-phase switching converter is further provided, comprising: a plurality of switching circuits connected in parallel to provide an output voltage; and the controller as described above.

[0008] According to an embodiment of the present invention, a control method for a multi-phase switching converter is also proposed, including: generating a comparison signal based on the output voltage and a reference signal of the multi-phase switching converter; providing an initial on-time signal to control the initial on-time of each switching circuit in the multi-phase switching converter; generating an adjusted on-time signal according to the initial on-time signal and the period of the comparison signal, so as to adjust the on-time of the corresponding switching circuit according to the period of the comparison signal on the basis of the initial on-time; controlling multiple switching circuits in the multi-phase switching converter to turn on in sequence according to the comparison signal; and controlling the turn-off moment of the corresponding switching circuit according to the adjusted on-time signal.

[0009] The multi-phase switching converter of the embodiment of the present invention can adjust the conduction time of multiple switching circuits in real time according to the period of the comparison signal, which is more flexible in control and ensures the power supply capacity of the multi-phase switching converter when the switching frequency increases, thereby having a faster response speed. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] In order to better understand the present invention, the present invention will be described in detail according to the following drawings:

[0011] Figure 1 is a circuit diagram of a multi-phase switching circuit 100 according to an embodiment of the present invention;

[0012] Figure 2 According to an embodiment of the present invention Figure 1 The flowchart of the method 200 of adjusting the conduction duration of the plurality of switch circuits 11_1 to 11_n by the duration adjustment unit 23 is shown;

[0013] Figure 3 According to an embodiment of the present invention Figure 1 The waveform diagram of the multi-phase switching converter 100 is shown;

[0014] Figure 4A is a circuit diagram of a duration adjustment unit 23A according to an embodiment of the present invention;

[0015] Figure 4B is a circuit diagram of a duration adjustment unit 23B according to an embodiment of the present invention;

[0016] Figure 5 is a circuit diagram of a switch control unit 24A according to an embodiment of the present invention;

[0017] Figure 6 is a circuit diagram of a controller 20A according to another embodiment of the present invention;

[0018] Figure 7 FIG. 7 is a flow chart of a control method 700 of a multi-phase switching converter according to an embodiment of the present invention.

[0019] In the drawings, the same or corresponding reference numerals are used to designate the same or corresponding elements. DETAILED DESCRIPTION

[0020] The specific embodiments of the present invention will be described in detail below. It should be noted that the embodiments described herein are only for illustration and are not intended to limit the present invention. In the following description, a large number of specific details are set forth in order to provide a thorough understanding of the present invention. However, it is obvious to those of ordinary skill in the art that these specific details do not have to be used to implement the present invention. In other examples, in order to avoid confusing the present invention, known circuits, materials or methods are not specifically described.

[0021] Throughout the specification, reference to "one embodiment", "embodiment", "one example" or "example" means that a particular feature, structure or characteristic described in conjunction with the embodiment or example is included in at least one embodiment of the present invention. Therefore, the phrases "in one embodiment", "in an embodiment", "one example" or "example" that appear in various places throughout the specification do not necessarily refer to the same embodiment or example. In addition, specific features, structures or characteristics can be combined in one or more embodiments or examples in any appropriate combination and / or sub-combination. In addition, it should be understood by those of ordinary skill in the art that the drawings provided herein are for illustrative purposes, and the drawings are not necessarily drawn to scale. It should be understood that when an element is said to be "coupled to" or "connected to" another element, it can be directly coupled or coupled to another element or there can be an intermediate element. On the contrary, when an element is said to be "directly coupled to" or "directly connected to" another element, there is no intermediate element. The same reference numerals indicate the same element. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0022] Figure 1 FIG. 1 is a circuit diagram of a multi-phase switch circuit 100 according to an embodiment of the present invention. The multi-phase switch circuit 100 receives an input voltage Vin and provides an output voltage Vo and an output current Io to a load. Figure 1 In the illustrated embodiment, the multi-phase switching circuit 100 includes a power circuit 10 composed of a plurality of switching circuits 11_1 to 11_n connected in parallel, and a controller 20, wherein n is a natural number greater than 1, representing the number of switching circuits, that is, the number of phases of the multi-phase switching converter 100. Each switching circuit constitutes one phase of the multi-phase switching converter. Figure 1 In the illustrated embodiment, the controller 20 includes a comparison circuit 21 , an initial duration generating unit 22 , a duration adjusting unit 23 , and a switch control unit 24 .

[0023] The comparison circuit 21 generates a comparison signal SET by comparing the feedback signal Vfb representing the output voltage Vo with the reference signal Vref. The reference signal Vref is, for example, equal to the target voltage value Vtgt minus the slope compensation signal Vslope. The target voltage value Vtgt is the target value of the output voltage Vo that the multi-phase switching circuit 100 needs to provide. In another embodiment, the slope compensation signal Vslope may also be superimposed on the feedback signal Vfb.

[0024] The initial duration generating unit 22 provides an initial conduction duration signal CTini to control the initial conduction duration Tini of each switch circuit, and to control the conduction duration of each switch circuit (e.g., the conduction duration of at least one switch in the switch circuit) when the multi-phase switching converter 100 is in steady-state operation (e.g., the output current Io and the output voltage Vo are stable). In one embodiment, the initial conduction duration Tini is a fixed duration. In another embodiment, the initial conduction duration Tini varies with the preset switching period Ts, the input voltage Vin, and / or the target voltage value Vtgt. The preset switching period Ts represents the switching period of the switch circuits 11_1 to 11_n in steady-state operation.

[0025] The duration adjustment unit 23 provides an adjusted conduction duration signal CTon according to the initial conduction duration signal CTini and the comparison signal SET, so as to adjust the conduction duration Ton of the plurality of switch circuits 11_1 to 11_n according to the period Tset of the comparison signal SET on the basis of the initial conduction duration Tini. In one embodiment, when the period Tset of the comparison signal SET is greater than the adjustment period Tadj, the duration adjustment unit 23 controls the conduction duration Ton of the switch circuits 11_1 to 11_n to be equal to the initial conduction duration Tini. In one embodiment, when the period Tset of the comparison signal SET is less than the adjustment period Tadj, the duration adjustment unit 23 controls the conduction duration Ton of the switch circuits 11_1 to 11_n to change with the change of the period Tset of the comparison signal SET. For example, when the period Tset of the comparison signal SET increases, the conduction duration Ton of the control switch circuits 11_1 to 11_n decreases, and when the period Tset of the comparison signal SET decreases, the conduction duration Ton of the control switch circuits 11_1 to 11_n increases. In one embodiment, the adjustment period Tadj is less than one nth of the preset switching period Ts, that is, Tadj <Ts / n。

[0026] The switch control unit 24 provides a plurality of pulse width modulation signals PWM1-PWMn to control the plurality of switch circuits 11_1-11_n according to the comparison signal SET and the adjusted on-time signal CTon. The switch control unit 24 controls the plurality of switch circuits 11_1-11_n to be turned on in sequence according to the comparison signal SET (for example, controls at least one switch tube in the switch circuits 11_1-11_n to be turned on in sequence), and controls the turn-off time of the plurality of switch circuits 11_1-11_n according to the adjusted on-time signal CTon (for example, controls the turn-off time of at least one switch tube in the switch circuits 11_1-11_n).

[0027] The multi-phase switch circuit 100 according to the embodiment of the present invention can adjust the conduction time Ton of the multiple switch circuits 11_1 to 11_n in real time according to the period Tset of the comparison signal SET, and the control is more flexible. Especially when the switching frequency fs is as high as 2MHz or more, due to factors such as load current extraction, the period Tset of the comparison signal SET is further reduced. By extending the conduction time Ton, the power supply capacity of the multi-phase switch converter 100 is guaranteed, so that it has a faster response speed. Further, when the period Tset of the comparison signal SET increases, the conduction time Ton is reduced, and when the period Tset of the comparison signal SET decreases, the conduction time Ton is increased, which improves the accuracy of control and ensures that the output voltage Vo of the multi-phase switch converter 100 is more stable. In addition, setting the adjustment period Tadj can further improve the system robustness of the multi-phase switch converter 100 and reduce unnecessary fluctuations in the switching frequency fs.

[0028] Each switch circuit may include, for example, a buck switch circuit, a boost switch circuit, a buck-boost switch circuit, etc. Figure 1 The embodiment shown is described by taking a buck type switching circuit as an example. Figure 1 In the illustrated embodiment, each switch circuit includes an upper switch tube S1, a lower switch tube S2, and an output inductor Lo. The first end of the upper switch tube S1 receives the input voltage Vin, the second end of the upper switch tube S1 is coupled to the first end of the lower switch tube S2 and the first end of the output inductor Lo, the second end of the lower switch tube S2 is coupled to the reference ground, and the second end of the output inductor Lo is coupled to the output capacitor Co to provide an output voltage Vo. The upper switch tube S1 and the lower switch tube S2 are complementary turned on under the control of the corresponding pulse width modulation signal. For example, the pulse width modulation signal PWM1 controls the upper switch tube S1 and the lower switch tube S2 in the switch circuit 11_1 to be complementary turned on, the pulse width modulation signal PWM2 controls the upper switch tube S1 and the lower switch tube S2 in the switch circuit 11_2 to be complementary turned on, and the pulse width modulation signal PWMn controls the upper switch tube S1 and the lower switch tube S2 in the switch circuit 11_n to be complementary turned on. Controlling the switch circuit to turn on, for example, includes controlling the corresponding upper switch tube S1 to turn on, and controlling the switch circuit to turn off, for example, includes controlling the corresponding upper switch tube S1 to turn off. Controlling the on-time of the switch circuit, for example, includes controlling the on-time of the upper switch tube S1 in a switching cycle.

[0029] Figure 2 According to an embodiment of the present invention Figure 1 The flowchart of the method 200 in which the duration adjustment unit 23 adjusts the on-times of the plurality of switch circuits 11_1 - 11_n according to the period Tset of the comparison signal SET includes steps S11 - S14 .

[0030] In step S11, the period Tset of the comparison signal SET is detected. In step S12, it is determined whether the period Tset of the comparison signal SET is less than the adjustment period Tadj. When the period Tset of the comparison signal SET is less than the adjustment period Tadj, the process proceeds to step S13, and the on-time Ton of the control switch circuits 11_1 to 11_n is increased in response to the decrease of the period Tset of the comparison signal SET, and decreased in response to the increase of the period Tset of the comparison signal SET. When the period Tset of the comparison signal SET is greater than the adjustment period Tadj, the process proceeds to step S14, and the on-time Ton of the control switch circuits 11_1 to 11_n is equal to the initial on-time Tini.

[0031] Figure 3 According to an embodiment of the present invention Figure 1 The waveform diagram of the multi-phase switching converter 100 is shown. Figure 3 The illustrated embodiment is described by taking n equal to 4 as an example, that is, taking the multi-phase switching converter 100 including the switching circuits 11_1 to 11_4 as an example. Those skilled in the art will appreciate that n may also be less than or greater than 4. Figure 3 The waveforms shown are, from top to bottom, output current Io, feedback signal Vfb representing output voltage Vo, comparison signal SET, and pulse width modulation signals PWM1 to PWM4. Figure 3As shown, a comparison signal SET is generated based on the comparison between the feedback signal Vfb and the reference signal Vref to control the multiple switch circuits 11_1 to 11_4 to be turned on in sequence. Before time t1, the multi-phase switching converter 100 operates in a steady state, and the period of the comparison signal SET is equal to the preset comparison period Ts / n, that is, the preset switching period Ts divided by the number of phases n, and the conduction time of each switch circuit 11_1 to 11_4 is equal to the initial conduction time Tini. At time t1, due to the change of the output current Io, the feedback signal Vfb representing the output voltage Vo decreases, and the period Tset of the comparison signal SET decreases rapidly. At time t2, it is detected that the period Tset of the comparison signal SET decreases to a value Ts1 less than the adjustment period Tadj, and the conduction time of the currently turned-on switch circuit 11_4 is controlled by the pulse width modulation signal PWM4 to increase to greater than the initial conduction time Tini, for example, equal to the sum of the initial conduction time Tini and the adjustment time dT1 (Tini+dT1). Then, at time t3, it is detected that the value Ts2 of the period Tset of the comparison signal SET is greater than Ts1, and the on-time of the currently turned-on switch circuit 11_2 is controlled to be reduced to the sum of the initial on-time Tini and the adjustment time dT2 (Tini+dT2), and the adjustment time dT2 is less than the adjustment time dT1. At time t4, it is detected that the value Ts3 of the period Tset of the comparison signal SET is greater than the adjustment period Tadj, and the on-time of the currently turned-on switch circuit 11_3 is controlled to be equal to the initial on-time Tini.

[0032] Figure 4A FIG4 is a circuit diagram of a duration adjustment unit 23A according to an embodiment of the present invention. In the embodiment shown in FIG4 , the duration adjustment unit 23A includes a period detection unit 230 and a conduction duration calculation unit 41. The period detection unit 230 provides a period Tset of a comparison signal SET according to a comparison signal SET. The period detection unit 230 can be timed by a timer, for example, or by charging and discharging a capacitor. The conduction duration calculation unit 41 provides an adjusted conduction duration signal CTon according to the period Tset of the comparison signal SET and the initial conduction duration signal CTini, wherein when the period Tset of the comparison signal SET is less than the adjustment period Tadj, the adjusted conduction duration signal CTon controls the conduction duration Ton of the current switch circuit to be equal to the sum of the initial conduction duration Tini and the adjustment duration dT (Tini+dT), the smaller the period Tset of the comparison signal SET, the longer the adjustment duration dT, and thus the longer the conduction duration Ton of the current switch circuit. When the period Tset of the comparison signal SET is greater than the adjustment period Tadj, the adjusted on-time signal CTon controls the on-time Ton of the current switch circuit to be equal to the initial on-time Tini.

[0033] exist Figure 4AIn the illustrated embodiment, the conduction duration calculation unit 41 includes an operation unit 231, a comparison unit 232, and a selection unit 233. The operation unit 231 obtains the adjustment signal Cdt according to the initial conduction duration signal CTini and the period Tset of the comparison signal SET. The comparison unit 232 compares the period Tset of the comparison signal SET with the adjustment period Tadj to obtain the selection signal Sel1. The selection unit 233 selects one of the initial conduction duration signal CTini and the adjustment signal Cdt as the conduction duration signal CTon according to the selection signal Sel1. When the period Tset of the comparison signal SET is greater than the adjustment period Tadj, the selection unit 233 selects the initial conduction duration signal CTini as the conduction duration signal CTon to control the conduction duration Ton of the current switch circuit to be equal to the initial conduction duration Tini. When the period Tset of the comparison signal SET is less than the adjustment period Tadj, the selection unit 233 selects the adjustment signal Cdt as the on-time signal CTon to control the on-time Ton of the current switch circuit to be equal to the sum of the initial on-time Tini and the adjustment time dT (Tini+dT). In one embodiment, the adjustment time dT and the period Tset of the comparison signal SET change in opposite directions. That is, the larger the period Tset of the comparison signal SET, the smaller the adjustment time dT, and the smaller the period Tset of the comparison signal SET, the larger the adjustment time dT.

[0034] In one embodiment, the duration adjustment unit 23A further includes an adjustment period calculation unit 234. The adjustment period calculation unit 234 calculates the adjustment period Tadj according to the preset comparison period Ts / n, so that the adjustment period Tadj is less than the preset comparison period Ts / n. For example, the adjustment period Tadj is equal to 0.8 times the preset comparison period Ts / n (Tadj=0.8Ts / n).

[0035] Figure 4B FIG. 2 is a circuit diagram of a duration adjustment unit 23B according to an embodiment of the present invention. Figure 4BIn the illustrated embodiment, the duration adjustment unit 23B includes a period detection unit 230 and a conduction duration calculation unit 42. The period detection unit 230 provides a period Tset of the comparison signal SET according to the comparison signal SET. The conduction duration calculation unit 42 provides a temporary conduction duration signal CTon_adp according to the period Tset of the comparison signal SET, the initial conduction duration signal CTini, and the preset comparison period Ts / n. When the temporary conduction duration Ton_adp represented by the temporary conduction duration signal CTon_adp is greater than the adjustment threshold Adth, the conduction duration calculation unit 42 provides an adjusted conduction duration signal CTon according to the temporary conduction duration signal CTon_adp to control the conduction duration Ton of the current switch circuit to be equal to the temporary conduction duration Ton_adp. When the temporary on-time Ton_adp represented by the temporary on-time signal CTon_adp is less than the adjustment threshold Adth, the on-time calculation unit 42 provides an adjusted on-time signal CTon according to the initial on-time signal CTini to control the on-time Ton of the current switch circuit to be equal to the initial on-time Tini.

[0036] exist Figure 4B In the illustrated embodiment, the conduction duration calculation unit 42 includes an operation unit 235, a comparison unit 236, and a selection unit 237. The operation unit 236 generates a temporary conduction duration signal CTon_adp according to the initial conduction duration signal CTini, the period Tset of the comparison signal SET, and the preset comparison period Ts / n, so as to obtain the temporary conduction duration Ton_adp according to formula (1).

[0037] Ton_adp=Tini*(Ts / n) / Tset (1)

[0038] The comparison unit 236 generates a selection signal Sel according to the comparison between the temporary on-time Ton_adp and the adjustment threshold Adth. The selection unit 237 selects one of the initial on-time signal CTini and the temporary on-time signal CTon_adp as the on-time signal CTon according to the selection signal Sel. In one embodiment, when the temporary on-time Ton_adp is greater than the adjustment threshold Adth, the selection unit 237 selects the temporary on-time signal CTon_adp as the on-time signal CTon, otherwise the selection unit 237 selects the initial on-time signal CTini as the on-time signal CTon.

[0039] In one embodiment, the duration adjustment unit 23B further includes an adjustment threshold calculation unit 238. The adjustment threshold calculation unit 238 calculates the adjustment threshold Adth according to the initial conduction duration Tini, so that the adjustment threshold Adth is greater than the initial conduction duration Tini. For example, the adjustment threshold Adth is equal to 1.2 times the initial conduction duration Tini (Adth=1.2Tini).

[0040] Figure 5 FIG. 2 is a circuit diagram of a switch control unit 24A according to an embodiment of the present invention. Figure 5 In the illustrated embodiment, the switch control unit 24A includes a frequency division unit 241 and a plurality of pulse width modulation units 242_1 to 242_n. The frequency division unit 241 receives a comparison signal SET and generates a plurality of set signals Set1 to Setn according to the comparison signal SET to control the plurality of switch circuits 11_1 to 11_n to be turned on in sequence. The pulse width modulation units 242_1 to 242_n receive the set signals Set1 to Setn and the conduction duration signal CTon, respectively, and provide pulse width modulation signals PWM1 to PWMn. In one embodiment, each pulse width modulation unit controls the conduction of the corresponding switch circuit according to the corresponding set signal, and controls the turn-off of the corresponding switch circuit according to the conduction duration signal CTon. For example, the pulse width modulation unit 242_1 provides the pulse width modulation signal PWM1 according to the set signal Set1 and the on-time signal CTon to control the switch circuit 11_1, the pulse width modulation unit 242_2 provides the pulse width modulation signal PWM2 according to the set signal Set2 and the on-time signal CTon to control the switch circuit 11_2, and the pulse width modulation unit 242_n provides the pulse width modulation signal PWMn according to the set signal Setn and the on-time signal CTon to control the switch circuit 11_n.

[0041] In one embodiment, each pulse width modulation unit includes a shutdown control unit 51 and an RS trigger circuit 52. The pulse width modulation unit 242_1 is taken as an example for description. The shutdown control unit 51 generates a shutdown control signal COT1 according to the on-time signal CTon and the pulse width modulation signal PWM1 to control the duration of the pulse width modulation signal PWM1 in the first state (e.g., high level), thereby controlling the on-time of the corresponding switch circuit 11_1. The set terminal S of the RS trigger circuit 52 receives the set signal Set1, the reset terminal R receives the shutdown control signal COT1, and the output terminal Q provides the pulse width modulation signal PWM1. The pulse width modulation signal PWM1 changes to the first state under the control of the set signal Set1 to control the switch circuit 11_1 to be turned on, and the pulse width modulation signal PWM2 changes to the second state (e.g., low level) under the control of the shutdown control signal COT1 to control the switch circuit 11_1 to be turned off.

[0042] Figure 6 FIG. 2 is a circuit diagram of a controller 20A according to another embodiment of the present invention. In one embodiment, the controller 20A is integrated on an integrated circuit (IC), including switch control pins PWM1 to PWMn for providing pulse width modulation signals PWM1 to PWMn, a remote voltage feedback pin VOSEN, a remote voltage feedback return pin VORTN, and communication pins SCLK_P, SDA_P, ALT_P, SCLK, and SDIO. Figure 6 In the embodiment shown, the controller 20A includes a programmable circuit 60. The programmable circuit 60 may be, for example, a field programmable gate array (FPGA), a complex programmable logic device (CPLD), a microprogrammed control unit (MCU), etc. In one embodiment, the programmable circuit 60 is used to implement, for example, Figure 1 The initial duration generating unit 22, the duration adjusting unit 23, and the switch control unit 24 are shown.

[0043] In one embodiment, the remote voltage feedback pin VOSEN and the remote voltage feedback return pin VORTN are used to couple to both ends of the output capacitor Co to sample the output voltage Vo. In one embodiment, the controller 20A includes a differential amplifier 61, two input terminals of the differential amplifier 61 are respectively coupled to the remote voltage feedback pin VOSEN and the remote voltage feedback return pin VORTN, and the output terminal of the differential amplifier 61 provides a voltage feedback signal Vfb.

[0044] In one embodiment, the controller 20A further includes an interface circuit 62 coupled to the communication pins SCLK and SDIO to receive a voltage identification code VID for setting the output voltage Vo. The interface circuit 62 provides a target voltage value Vtgt according to the voltage identification code VID. In one embodiment, the controller 20A further includes an interface circuit 64 coupled to the communication pins SCLK_P, SDA_P, and ALT_P to receive user settings for the multi-phase switching converter 100, such as output voltage, output timing, switching frequency fs, switching period Ts, and / or number of phases n. The interface circuit 64 includes, for example, a power bus (PMBus) interface circuit, a system management bus (SMBus) interface circuit, etc.

[0045] Figure 71 is a flow chart of a control method 700 of a multi-phase switching converter according to an embodiment of the present invention, comprising steps S11 to S15.

[0046] In step S11, a comparison signal is generated based on the output voltage of the multi-phase switching converter and a reference signal. In step S12, an initial on-time signal is provided to control the initial on-time of each switching circuit. In step S13, an adjusted on-time signal is generated according to the initial on-time signal and the cycle of the comparison signal, so as to adjust the on-time of the current switching circuit according to the cycle of the comparison signal on the basis of the initial on-time. In step S14, multiple switching circuits in the multi-phase switching converter are controlled to be turned on in sequence according to the comparison signal. And in step S15, the turn-off moment of the current switching circuit is controlled according to the adjusted on-time signal.

[0047] Although the present invention has been described with reference to several typical embodiments, it should be understood that the terms used are illustrative and exemplary, rather than restrictive. Since the present invention can be embodied in a variety of forms without departing from the spirit or essence of the invention, it should be understood that the above embodiments are not limited to any of the foregoing details, but should be interpreted broadly within the spirit and scope defined by the appended claims, so all changes and modifications falling within the scope of the claims or their equivalents should be covered by the appended claims.

Claims

1. A controller for a multi-phase switching converter, include: A comparison circuit generates a comparison signal according to the output voltage of the multi-phase switching converter and a reference signal; An initial duration generating unit, providing an initial conduction duration signal to control the initial conduction duration of each switch circuit in the multi-phase switching converter; A duration adjustment unit, providing an adjusted on-time signal according to the initial on-time signal and the comparison signal, so as to adjust the on-time of multiple switch circuits in the multi-phase switching converter according to the period of the comparison signal on the basis of the initial on-time; as well as A switch control unit provides multiple pulse width modulation signals to control multiple switch circuits in a multi-phase switch converter according to a comparison signal and an adjusted on-time signal, wherein the switch control unit controls the multiple switch circuits to be turned on in sequence according to the comparison signal, and controls the turn-off moments of the multiple switch circuits in the multi-phase switch converter according to the adjusted on-time signal. 2 . The controller as claimed in claim 1 , wherein when the period of the comparison signal is smaller than the adjustment period, the duration adjustment unit controls the on-time of the corresponding switch circuit to change with the change of the period of the comparison signal. 3 . The controller as claimed in claim 2 , wherein when the period of the comparison signal is greater than the adjustment period, the duration adjustment unit controls the on-time of the corresponding switch circuit to be equal to the initial on-time.

4. The controller as claimed in claim 2, wherein the regulation period is less than one nth of the preset switching periods of the plurality of switch circuits, where n is the number of the switch circuits.

5. The controller as claimed in claim 1, wherein when the period of the comparison signal is smaller than the adjustment period, the duration adjustment unit controls the on-time of the corresponding switch circuit to decrease in response to an increase in the period of the comparison signal, and to increase in response to a decrease in the period of the comparison signal.

6. The controller according to claim 1, wherein the duration adjustment unit include: The period detection unit provides a period of the comparison signal according to the comparison signal; as well as A conduction duration calculation unit, providing an adjusted conduction duration signal according to a period of a comparison signal and an initial conduction duration signal; in When the period of the comparison signal is less than the adjustment period, the adjusted on-time signal controls the on-time of the corresponding switch circuit to be equal to the sum of the initial on-time and the adjustment time, and the smaller the period of the comparison signal, the greater the adjustment time.

7. The controller according to claim 1, wherein the duration adjustment unit include: The period detection unit provides a period of the comparison signal according to the comparison signal; as well as The on-time calculation unit provides a temporary on-time signal according to the period of the comparison signal, the initial on-time signal, and a preset comparison period, wherein when the temporary on-time represented by the temporary on-time signal is greater than the adjustment threshold, the on-time calculation unit provides an adjusted on-time signal according to the temporary on-time signal to control the on-time of the corresponding switch circuit to be equal to the temporary on-time.

8. A controller for a multi-phase switching converter, include: A comparison circuit generates a comparison signal according to the output voltage of the multi-phase switching converter and a reference signal; as well as A programmable circuit generates a plurality of pulse width modulation signals according to the comparison signal to control a plurality of switch circuits in the multi-phase switch converter, wherein the programmable control circuit controls the plurality of switch circuits to be turned on in sequence according to the comparison signal, and controls the turn-off time of the plurality of switch circuits according to the cycle and the initial turn-on time of the comparison signal; in When the period of the comparison signal is less than the adjustment period, the programmable circuit controls the on-time of the corresponding switch circuit to decrease in response to an increase in the period of the comparison signal, and to increase in response to a decrease in the comparison period; as well as When the period of the comparison signal is greater than the adjustment period, the programmable circuit controls the conduction time length of the corresponding switch circuit to be equal to the initial conduction time length.

9. A multiphase switching converter, include: a plurality of switching circuits connected in parallel to provide an output voltage; as well as A controller as claimed in any one of claims 1 to 9.

10. A control method for a multi-phase switching converter, include: generating a comparison signal based on the output voltage of the multi-phase switching converter and a reference signal; Providing an initial on-time signal to control the initial on-time of each switch circuit in the multi-phase switching converter; Generate an adjusted on-time signal according to the initial on-time signal and the period of the comparison signal, so as to adjust the on-time of the corresponding switch circuit according to the period of the comparison signal on the basis of the initial on-time; Controlling multiple switch circuits in the multi-phase switching converter to conduct in sequence according to the comparison signal; and The turn-off time of the corresponding switch circuit is controlled according to the adjusted turn-on time signal.

11. The control method according to claim 10, wherein When the period of the comparison signal is less than the adjustment period, controlling the on-time of the corresponding switch circuit to decrease in response to an increase in the period of the comparison signal, and to increase in response to a decrease in the comparison period; and When the period of the comparison signal is greater than the adjustment period, the conduction time length of the corresponding switch circuit is controlled to be equal to the initial conduction time length.

12. The control method as claimed in claim 11, wherein the regulation period is less than one nth of the preset switching period of the plurality of switching circuits in the multi-phase switching converter, where n is the number of the switching circuits.

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