Multi-phase switching converter, controller and control method thereof

Abstract

The application discloses a multiphase switching converter, a controller and a control method thereof. The controller comprises a comparison circuit, a time length adjusting unit and a switch control unit. The comparison circuit generates a comparison signal according to an output voltage and a reference signal. The time length adjusting unit provides an adjusted turn-on time length signal according to an initial turn-on time length signal and the comparison signal, so as to adjust the turn-on time length of a plurality of switch circuits in the multiphase switching converter according to the period of the comparison signal on the basis of the initial turn-on time length. The switch control unit controls the plurality of switch circuits to turn on in sequence according to the comparison signal, and controls the turn-off time of the plurality of switch circuits according to the adjusted turn-on time length signal. The multiphase switching converter adjusts the turn-on time length of the plurality of switch circuits in real time according to the period of the comparison signal, the control is more flexible, the power supply capacity is ensured when the switching frequency is increased, and therefore the response speed is faster.

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 lower output voltages and higher output currents are in demand, along with increasingly stringent requirements for thermal and transient response performance. Multiphase switching converters have gained widespread application due to their superior performance. A multiphase switching converter comprises multiple switching circuits, each representing a phase, with the outputs of the multiple switching circuits coupled together to provide an output voltage to the load.

[0003] To achieve fast load response, constant on-time control is increasingly used in multi-phase switching converters. However, as the number of phases increases and the switching frequency increases, setting a stable and reliable constant on-time control for multi-phase switching converters becomes a new challenge. Summary of the Invention

[0004] Therefore, the purpose of the present invention is to solve the above 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 based on 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 based on 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 switching control unit, which provides multiple pulse width modulation signals based on the comparison signal and the adjusted on-time signal to control the multiple switching circuits in the multi-phase switching converter, wherein the switching 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 based on 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 based on 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 with reference 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 on-time 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 Waveform diagram of the multi-phase switching converter 100 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 the 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 for 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] Specific embodiments of the present invention will be described in detail below. It should be noted that the embodiments described herein are for illustrative purposes only and are not intended to limit the present invention. In the following description, numerous specific details are set forth to provide a thorough understanding of the present invention. However, it will be apparent to one of ordinary skill in the art that these specific details are not necessarily required to practice the present invention. In other instances, well-known circuits, materials, or methods are not described in detail to avoid obscuring the present invention.

[0021] Throughout this specification, references to "one embodiment," "an embodiment," "an example," or "an example" mean that a particular feature, structure, or characteristic described in connection with that embodiment or example is included in at least one embodiment of the present invention. Therefore, the phrases "in one embodiment," "in an embodiment," "an example," or "an example" that appear in various places throughout this specification do not necessarily refer to the same embodiment or example. Furthermore, particular features, structures, or characteristics may be combined in one or more embodiments or examples in any suitable combinations and / or subcombinations. Furthermore, those skilled in the art will appreciate that the figures provided herein are for illustrative purposes only and are not necessarily drawn to scale. It should be understood that when an element is referred to as being "coupled to" or "connected to" another element, it can be directly coupled or coupled to the other element or intervening elements may be present. In contrast, when an element is referred to as being "directly coupled to" or "directly connected to" another element, there are no intervening elements. Identical reference numerals indicate identical elements. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0022] Figure 1 FIG. 1 is a circuit diagram of a multi-phase switching circuit 100 according to an embodiment of the present invention. The multi-phase switching 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, where 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] Comparison circuit 21 generates a comparison signal SET by comparing feedback signal Vfb, representing output voltage Vo, with reference signal Vref. Reference signal Vref is, for example, equal to target voltage Vtgt minus slope compensation signal Vramp. Target voltage Vtgt is the target value of output voltage Vo to be provided by multi-phase switching circuit 100. In another embodiment, slope compensation signal Vramp may also be superimposed on feedback signal Vfb.

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

[0025] The duration adjustment unit 23 provides an adjusted on-time signal CTon based on the initial on-time signal CTini and the comparison signal SET. This adjusts the on-times Ton of the multiple switch circuits 11_1 to 11_n based on the initial on-time Tini and the period Tset of the comparison signal SET. 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 on-times Ton of the switch circuits 11_1 to 11_n to be equal to the initial on-time 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 on-times Ton of the switch circuits 11_1 to 11_n to vary with the period Tset of the comparison signal SET. For example, as the period Tset of the comparison signal SET increases, the on-times Ton of the switch circuits 11_1 to 11_n decrease, and as the period Tset of the comparison signal SET decreases, the on-times Ton of the switch circuits 11_1 to 11_n increase. 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 based on the comparison signal SET and the adjusted on-time signal CTon to control the plurality of switch circuits 11_1-11_n. The switch control unit 24 sequentially turns on the plurality of switch circuits 11_1-11_n based on the comparison signal SET (e.g., controls at least one switch in the plurality of switch circuits 11_1-11_n to turn on in sequence), and controls the turn-off timing of the plurality of switch circuits 11_1-11_n based on the adjusted on-time signal CTon (e.g., controls the turn-off timing of at least one switch in the plurality of switch circuits 11_1-11_n).

[0027] According to an embodiment of the present invention, the multi-phase switching circuit 100 can adjust the on-times Ton of the multiple switching circuits 11_1 to 11_n in real time based on the period Tset of the comparison signal SET, providing more flexible control. Especially when the switching frequency fs is above 2 MHz, as factors such as load current draw cause the period Tset of the comparison signal SET to decrease further, extending the on-time Ton ensures the power supply capability of the multi-phase switching converter 100, thereby achieving faster response speed. Furthermore, by reducing the on-time Ton when the period Tset of the comparison signal SET increases, and increasing the on-time Ton when the period Tset of the comparison signal SET decreases, control accuracy is improved, ensuring a more stable output voltage Vo of the multi-phase switching converter 100. Furthermore, setting the adjustment period Tadj further enhances the system robustness of the multi-phase switching converter 100 and reduces unnecessary fluctuations in the switching frequency fs.

[0028] Each switching circuit may include, for example, a buck switching circuit, a boost switching circuit, a buck-boost switching circuit, etc. Figure 1 The embodiment shown is described by taking a buck switching circuit as an example. Figure 1 In the illustrated embodiment, each switching circuit includes an upper switching transistor S1, a lower switching transistor S2, and an output inductor Lo. A first terminal of the upper switching transistor S1 receives an input voltage Vin, a second terminal of the upper switching transistor S1 is coupled to a first terminal of the lower switching transistor S2 and a first terminal of the output inductor Lo, a second terminal of the lower switching transistor S2 is coupled to a reference ground, and a second terminal of the output inductor Lo is coupled to an output capacitor Co to provide an output voltage Vo. The upper switching transistor S1 and the lower switching transistor S2 are complementary-conducted under the control of corresponding pulse-width modulation signals. For example, the pulse-width modulation signal PWM1 controls the complementary conduction of the upper switching transistor S1 and the lower switching transistor S2 in the switching circuit 11_1, the pulse-width modulation signal PWM2 controls the complementary conduction of the upper switching transistor S1 and the lower switching transistor S2 in the switching circuit 11_2, and the pulse-width modulation signal PWMn controls the complementary conduction of the upper switching transistor S1 and the lower switching transistor S2 in the switching circuit 11_n. Controlling the switch circuit to be turned on, for example, includes controlling the corresponding upper switch S1 to be turned on, and controlling the switch circuit to be turned off, for example, includes controlling the corresponding upper switch S1 to be turned off. Controlling the on-time of the switch circuit, for example, includes controlling the on-time of the upper switch 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 to 11_n according to the period Tset of the comparison signal SET includes steps S11 to S14.

[0030] In step S11, the period Tset of the comparison signal SET is detected. In step S12, a determination is made as to 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, where the on-time duration Ton of the switch circuits 11_1-11_n is controlled to increase in response to a decrease in the period Tset of the comparison signal SET, and to decrease in response to an increase in 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, where the on-time duration Ton of the switch circuits 11_1-11_n is controlled to be equal to the initial on-time duration 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 sequential conduction of multiple switching circuits 11_1 to 11_4. Before time t1, the multi-phase switching converter 100 operates in a steady state. 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. The on-time of each switching circuit 11_1 to 11_4 is equal to the initial on-time Tini. At time t1, due to the change in 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 has decreased to a value Ts1 less than the adjustment period Tadj. The pulse width modulation signal PWM4 is used to control the on-time of the currently conducting switching circuit 11_4 to increase to a value greater than the initial on-time Tini, for example, equal to the sum of the initial on-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 reduced to the sum of the initial on-time Tini and the adjusted time dT2 (Tini + dT2), where the adjusted time dT2 is less than the adjusted 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 FIG. 2 is a circuit diagram of a duration adjustment unit 23A according to an embodiment of the present invention. Figure 4A In the illustrated embodiment, the duration adjustment unit 23A includes a period detection unit 230 and an on-time calculation unit 41. The period detection unit 230 provides a period Tset of the comparison signal SET based on the comparison signal SET. The period detection unit 230 can, for example, be timed by a timer or by charging and discharging a capacitor. The on-time calculation unit 41 provides an adjusted on-time signal CTon based on the period Tset of the comparison signal SET and the initial on-time signal CTini. When the period Tset of the comparison signal SET is less than the adjustment period Tadj, the adjusted on-time signal CTon controls the on-time Ton of the current switching circuit to be equal to the sum of the initial on-time Tini and the adjustment period dT (Tini+dT). The smaller the period Tset of the comparison signal SET, the longer the adjustment period dT, and thus the longer the on-time Ton of the current switching 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 switching circuit to be equal to the initial on-time Tini.

[0033] exist Figure 4A In the illustrated embodiment, the on-time calculation unit 41 includes a calculation unit 231, a comparison unit 232, and a selection unit 233. The calculation unit 231 generates the adjustment signal Cdt based on the initial on-time 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 generate a selection signal Sel1. The selection unit 233 selects one of the initial on-time signal CTini and the adjustment signal Cdt based on the selection signal Sel1 and outputs it as the on-time signal CTon. When the period Tset of the comparison signal SET is greater than the adjustment period Tadj, the selection unit 233 selects the initial on-time signal CTini as the on-time signal CTon, thereby controlling the on-time Ton of the current switching circuit to be equal to the initial on-time 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 switching 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 vice versa.

[0034] In one embodiment, the duration adjustment unit 23A further includes an adjustment period calculation unit 234. The adjustment period calculation unit 234 calculates an adjustment period Tadj based on a preset comparison period Ts / n, such 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 the 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 an on-time calculation unit 42. The period detection unit 230 provides a period Tset of the comparison signal SET based on the comparison signal SET. The on-time calculation unit 42 provides a temporary on-time signal CTon_adp based on the period Tset of the comparison signal SET, the initial on-time signal CTini, and a preset comparison period Ts / n. When the temporary on-time Ton_adp represented by the temporary on-time signal CTon_adp is greater than the adjustment threshold Adth, the on-time calculation unit 42 provides an adjusted on-time signal CTon based on the temporary on-time signal CTon_adp to control the on-time Ton of the current switching circuit to be equal to the temporary on-time 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 switching circuit to be equal to the initial on-time Tini.

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

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

[0038] Comparison unit 236 generates a selection signal Sel based on a comparison of the temporary on-duration Ton_adp with the adjustment threshold Adth. Selection unit 237 selects, based on selection signal Sel, either the initial on-duration signal CTini or the temporary on-duration signal CTon_adp as the on-duration signal CTon. In one embodiment, when the temporary on-duration Ton_adp is greater than the adjustment threshold Adth, selection unit 237 selects the temporary on-duration signal CTon_adp as the on-duration signal CTon. Otherwise, selection unit 237 selects the initial on-duration signal CTini as the on-duration 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 an adjustment threshold Adth based on the initial on-time Tini, so that the adjustment threshold Adth is greater than the initial on-time Tini. For example, the adjustment threshold Adth is equal to 1.2 times the initial on-time 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 divider 241 and multiple pulse-width modulation units 242_1 through 242_n. The frequency divider 241 receives a comparison signal SET and generates multiple set signals Set1 through Setn based on the comparison signal SET to sequentially turn on the multiple switch circuits 11_1 through 11_n. The pulse-width modulation units 242_1 through 242_n receive the set signals Set1 through Setn and the on-time signal CTon, respectively, and provide pulse-width modulation signals PWM1 through PWMn. In one embodiment, each pulse-width modulation unit turns on the corresponding switch circuit based on the corresponding set signal and turns off the corresponding switch circuit based on the on-time signal CTon. For example, the PWM unit 242_1 provides a PWM signal PWM1 based on the set signal Set1 and the on-time signal CTon to control the switch circuit 11_1. The PWM unit 242_2 provides a PWM signal PWM2 based on the set signal Set2 and the on-time signal CTon to control the switch circuit 11_2. The PWM unit 242_n provides a PWM signal PWMn based on 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 following description uses pulse width modulation unit 242_1 as an example. The shutdown control unit 51 generates a shutdown control signal COT1 based on the on-time signal CTon and the pulse width modulation signal PWM1 to control the duration of the pulse width modulation signal PWM1 in a first state (e.g., a high level), thereby controlling the on-time of the corresponding switch circuit 11_1. The RS trigger circuit 52 has a set terminal S that receives the set signal Set1, a reset terminal R that receives the shutdown control signal COT1, and an output terminal Q that provides the pulse width modulation signal PWM1. Under the control of the set signal Set1, the pulse width modulation signal PWM1 changes to the first state to turn on the switch circuit 11_1. Under the control of the shutdown control signal COT1, the pulse width modulation signal PWM2 changes to the second state (e.g., a low level) to turn off the switch circuit 11_1.

[0042] Figure 6 FIG2 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) and includes 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 coupled 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, whose two inputs are coupled to the remote voltage feedback pin VOSEN and the remote voltage feedback return pin VORTN, respectively, and whose output provides a voltage feedback signal Vfb.

[0044] In one embodiment, the controller 20A further includes an interface circuit 62 coupled to 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 based on the voltage identification code VID. In one embodiment, the controller 20A further includes an interface circuit 64 coupled to communication pins SCLK_P, SDA_P, and ALT_P to receive user settings for the multi-phase switching converter 100, such as the 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, and the like.

[0045] Figure 71 is a flow chart of a control method 700 for a multi-phase switching converter according to an embodiment of the present invention, including 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 based on the initial on-time signal and the period of the comparison signal to adjust the on-time of the current switching circuit based on the period 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 turn on in sequence based on the comparison signal. And in step S15, the turn-off moment of the current switching circuit is controlled based on the adjusted on-time signal.

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

Claims

1. A controller for a multi-phase switching converter, comprising: 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 on-time signal to control the initial on-time of each switching circuit in the multi-phase switching converter; a duration adjustment unit, providing an adjusted on-duration signal according to the initial on-duration signal and the comparison signal, so as to adjust the on-duration 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-duration; as well as a switch control unit, providing a plurality of pulse width modulation signals to control a plurality of switch circuits in the multi-phase switching converter according to the comparison signal and the adjusted on-time signal, wherein the switch control unit controls the plurality of switch circuits to be turned on in sequence according to the comparison signal, and controls the turn-off timing of the plurality of switch circuits in the multi-phase switching converter according to the adjusted on-time signal; in When the period of the comparison signal is less 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; as well as 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. 2 . The controller as claimed in claim 1 , wherein the regulation period is less than one nth of the preset switching periods of the plurality of switching circuits, where n is the number of the switching circuits.

3. The controller as claimed in claim 1 , wherein when the period of the comparison signal is less 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.

4. The controller according to claim 1 , wherein the duration adjustment unit comprises: 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 an adjusted on-time signal according to the period of the comparison signal and the initial on-time 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 longer the adjustment time.

5. The controller according to claim 1 , wherein the duration adjustment unit comprises: 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 based on the period of the comparison signal, the initial on-time signal, and a preset comparison period. 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 based on the temporary on-time signal to control the on-time of the corresponding switch circuit to be equal to the temporary on-time.

6. A controller for a multi-phase switching converter, comprising: 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 that 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 turning-off timing of the plurality of switching circuits according to the period and initial 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 on-time of the corresponding switch circuit to be equal to the initial on-time.

7. A multiphase switching converter comprising: a plurality of switching circuits connected in parallel to provide an output voltage; as well as The controller according to any one of claims 1 to 6.

8. A control method for a multi-phase switching converter, comprising: 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 switching 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 switching circuits in the multi-phase switching converter to conduct in sequence according to the comparison signal; and Controlling the turn-off moment of the corresponding switch circuit according to the adjusted on-time signal; in When the period of the comparison signal is less than the adjustment period, the on-time of the corresponding switch circuit is controlled 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 on-time of the corresponding switch circuit is controlled to be equal to the initial on-time. 9 . The control method according to claim 8 , wherein the regulation period is less than one nth of the preset switching periods 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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