Multi-phase switching power supply and phase number control method and control circuit thereof

Abstract

The invention discloses a multiphase switching power supply and a phase number control method and control circuit thereof, the multiphase switching power supply comprises n phases of power conversion circuits, n is an integer greater than or equal to 2, and the method comprises the following steps: controlling the working phase number of the multiphase switching power supply according to a first parameter and a load current; the first parameter comprises at least one of the input voltage, the output voltage and the temperature of the multiphase switching power supply, and the working phase number is the phase number of a power conversion circuit for power operation. Compared with the prior art that the working phase number of the multi-phase switching power supply is controlled only according to the load current, the method has the advantages that the multi-phase switching power supply can work closer to a real optimal efficiency curve and even work on the real optimal efficiency curve, and the efficiency is improved.

Description

Technical Field

[0001] This invention relates to the field of power electronics technology, and in particular to a multiphase switching power supply and its phase number control method and control circuit. Background Technology

[0002] Existing multiphase switching power supply control schemes operate with different numbers of phases under varying load current conditions. Under the same load current, the efficiency of a multiphase switching power supply varies depending on the number of phases it operates with. To ensure maximum efficiency under different load conditions, it is necessary to adjust the number of operating phases to maintain the multiphase switching power supply at its highest efficiency.

[0003] Existing phase control schemes for multiphase switching power supplies rely solely on load current to control the number of operating phases; that is, the number of operating phases changes only with load current. Specifically, these schemes derive multiple switching thresholds based on efficiency curves for different numbers of operating phases, aiming to achieve the optimal efficiency curve. The number of operating phases is then controlled based on the load current sampling signal and these thresholds. However, in existing schemes, these switching thresholds remain fixed regardless of changes in input voltage, output voltage, or temperature. In reality, the optimal efficiency curve obtained by existing technologies is not the true optimal efficiency curve switching threshold. The true optimal efficiency curve is related not only to load current but also to input voltage, output voltage, and temperature. Existing schemes fail to consider all these factors, resulting in the system not always operating on the true optimal efficiency curve and thus not reaching its maximum efficiency. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a multiphase switching power supply and a phase number control method and control circuit thereof, so as to solve the technical problem that the existing multiphase switching power supply cannot work on the true optimal efficiency curve and the efficiency cannot reach the highest level.

[0005] The technical solution of the present invention is, in a first aspect, to provide a phase number control method for a multiphase switching power supply, wherein the multiphase switching power supply includes an n-phase power conversion circuit, where n is an integer greater than or equal to 2, and the phase number control method includes: controlling the number of working phases of the multiphase switching power supply according to a first parameter and a load current;

[0006] The first parameter includes at least one of the input voltage, output voltage, and temperature of the multiphase switching power supply, and the number of operating phases is the number of phases of the power conversion circuit for power operation.

[0007] Optionally, the switching threshold of each adjacent number of working phases corresponding to the value of the first parameter sampling signal is obtained based on the first parameter sampling signal characterizing the first parameter;

[0008] The number of operating phases of the multiphase switching power supply is controlled based on the load current sampling signal characterizing the load current and the switching threshold of each adjacent operating phase corresponding to the first parameter sampling signal value.

[0009] Optionally, based on the first parameter sampling signal and the optimal switching load current information of the number of adjacent working phases under different values ​​of the first parameter, the switching threshold of each number of adjacent working phases corresponding to the value of the first parameter sampling signal is obtained.

[0010] The optimal switching load current information is the load current information corresponding to the intersection point of the efficiency curves of adjacent operating phases with the same first parameter.

[0011] Optionally, data is stored in the first register based on the optimal switching load current information of adjacent working phases under different sizes of the first parameter;

[0012] A lookup instruction is obtained based on the first parameter sampling signal, and data is read from the first register based on the lookup instruction to obtain the switching threshold of each adjacent working phase corresponding to the value of the first parameter sampling signal.

[0013] Optionally, the optimal switching load current information of adjacent working phases under different sizes of the first parameter is fitted to obtain the fitting formula corresponding to each adjacent working phase. The independent variable of the fitting formula can characterize the information of the first parameter or the first parameter sampling signal, and the dependent variable can characterize the information of the switching load current or switching threshold of the adjacent working phases.

[0014] The switching load current or switching threshold of each adjacent working phase under different sizes of the first parameter is obtained according to the fitting formula of each adjacent working phase, and the data is stored in the first register according to the switching load current or switching threshold of each adjacent working phase under different first parameters.

[0015] Optionally, the optimal switching load current information of adjacent working phases under different sizes of the first parameter is fitted to obtain the fitting formula corresponding to each adjacent working phase. The independent variable of the fitting formula can characterize the information of the first parameter or the first parameter sampling signal, and the dependent variable can characterize the information of the switching load current of adjacent working phases or the switching threshold of adjacent working phases.

[0016] Based on the first parameter sampling signal and the fitting formula of each adjacent working phase, the switching threshold of each adjacent working phase corresponding to the first parameter sampling signal value is obtained by calculation.

[0017] Optionally, the switching threshold of each adjacent working phase corresponding to the first parameter sampling signal is obtained by calculation based on the first parameter sampling signal, the fitting formula of each adjacent working phase corresponding to the first parameter sampling signal value, the optimal switching load current information of the adjacent working phase when the first parameter or the first parameter sampling signal is equal to a specific value, and the specific value.

[0018] Optionally, linear fitting is performed based on the optimal switching load current information of adjacent operating phases under different sizes of the first parameter to obtain the fitting formula for each adjacent operating phase.

[0019] Optionally, the load current sampling signal is compared with the switching threshold of each adjacent working phase corresponding to the first parameter sampling signal value, and the working phase of the multiphase switching power supply is controlled according to the comparison result.

[0020] Optionally, the first battery pack provides the input voltage to the multiphase switching power supply, and the first parameter includes the input voltage.

[0021] In a second aspect, the present invention also provides a control circuit for a multiphase switching power supply, the multiphase switching power supply including an n-phase power conversion circuit, wherein n is an integer greater than or equal to 2, and the control circuit controls the number of operating phases of the multiphase switching power supply according to a first parameter and a load current.

[0022] The first parameter includes at least one of the input voltage, output voltage, and temperature of the multiphase switching power supply, and the number of operating phases is the number of phases of the power conversion circuit for power operation.

[0023] Optionally, the control circuit includes:

[0024] The switching threshold generation unit outputs a switching threshold for each adjacent number of working phases corresponding to the value of the first parameter sampling signal, based on the first parameter sampling signal characterizing the first parameter.

[0025] The phase number control signal generation unit receives a load current sampling signal characterizing the load current, and receives the switching threshold of each adjacent working phase number corresponding to the first parameter sampling signal value output by the switching threshold generation unit, and outputs a phase number control signal according to the load current sampling signal and the switching threshold of each adjacent working phase number corresponding to the first parameter sampling signal value.

[0026] The control circuit controls the number of operating phases of the multiphase switching power supply according to the phase number control signal.

[0027] Optionally, the switching threshold generation unit obtains the switching threshold of each adjacent number of working phases corresponding to the value of the first parameter sampling signal based on the first parameter sampling signal and the optimal switching load current information of the adjacent number of working phases under different values ​​of the first parameter.

[0028] The optimal switching load current information is the load current information corresponding to the intersection point of the efficiency curves of adjacent operating phases with the same first parameter.

[0029] Optionally, the switching threshold generation unit includes an instruction generation unit and a first register.

[0030] The instruction generation unit receives the first parameter sampling signal and generates a lookup instruction based on the value of the first parameter sampling signal;

[0031] The switching threshold generation unit reads data from the first register according to the lookup instruction to obtain the switching threshold of each adjacent working phase number corresponding to the first parameter sampling signal value;

[0032] The data stored in the first register is obtained based on the optimal switching load current information of adjacent working phases under different sizes of the first parameter.

[0033] Optionally, the switching threshold generation unit includes a first calculation unit.

[0034] The first calculation unit receives the first parameter sampling signal and performs calculations based on the first parameter sampling signal and the fitting formula of each adjacent working phase number to output the switching threshold of each adjacent working phase number corresponding to the value of the first parameter sampling signal.

[0035] The fitting formula for each adjacent number of working phases is a formula obtained by fitting the optimal switching load current information of adjacent working phases under different sizes of the first parameter. The independent variable of the fitting formula can characterize the information of the first parameter or the first parameter sampling signal, and the dependent variable can characterize the information of the switching load current of adjacent working phases or the switching threshold of adjacent working phases.

[0036] Optionally, the switching threshold generation unit further includes a second register.

[0037] The first calculation unit reads data from the second register to obtain the fitting parameters of the fitting formula corresponding to each adjacent working phase number; and / or,

[0038] The optimal switching load current information for the number of adjacent working phases when the first parameter or the first parameter sampling signal is equal to a specific value.

[0039] Thirdly, the present invention also provides a multiphase switching power supply, the multiphase switching power supply including an n-phase power conversion circuit, the multiphase switching power supply including the control circuit described above, or using the phase number control method described above to control the number of working phases of the multiphase switching power supply.

[0040] The solution of the present invention has the following advantages: Compared with the prior art which controls the number of working phases of a multiphase switching power supply only based on the load current, the present invention controls the number of working phases of the multiphase switching power supply based on the first parameter and the load current, which enables the multiphase switching power supply to operate closer to the true optimal efficiency curve, or even operate on the true optimal efficiency curve, thus further improving efficiency compared with the prior art. Attached Figure Description

[0041] Figure 1 This is a schematic flowchart of a phase number control method for a multiphase switching power supply according to an embodiment of the present invention;

[0042] Figure 2 This is a flowchart illustrating a method for obtaining the switching threshold of each adjacent number of working phases corresponding to the value of the first parameter sampling signal according to an embodiment of the present invention.

[0043] Figure 3 This is a flowchart illustrating a method for obtaining the switching threshold of each adjacent number of working phases corresponding to the value of the first parameter sampling signal, according to another embodiment of the present invention.

[0044] Figure 4 This is a schematic diagram of the efficiency curve of a multiphase switching power supply according to an embodiment of the present invention;

[0045] Figure 5a According to Figure 4 A schematic diagram of the fitting curve of one embodiment;

[0046] Figure 5b According to Figure 4 A schematic diagram of the fitting curve of another embodiment;

[0047] Figure 6 This is a schematic diagram of the circuit structure of a multiphase switching power supply according to an embodiment of the present invention;

[0048] Figure 7 According to Figure 6 A schematic diagram of the circuit structure of the first embodiment of the switching threshold generation unit;

[0049] Figure 8 According to Figure 6 A schematic diagram of the circuit structure of the second embodiment of the switching threshold generation unit;

[0050] Figure 9 According to Figure 6A schematic diagram of the circuit structure of the switching threshold generation unit in the third embodiment. Detailed Implementation

[0051] The preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings, but the present invention is not limited to these embodiments. The present invention covers any substitutions, modifications, equivalent methods, and solutions made within the spirit and scope of the present invention.

[0052] To provide the public with a thorough understanding of the present invention, specific details are described in detail in the following preferred embodiments of the invention, but those skilled in the art can fully understand the invention without these details.

[0053] The invention is described more specifically in the following paragraphs by way of example with reference to the accompanying drawings. It should be noted that the drawings are in a simplified form and use non-precise proportions, and are only used to facilitate and clarify the illustration of the embodiments of the invention.

[0054] Figure 1 A flowchart illustrating a phase number control method for a multiphase switching power supply according to an embodiment of the present invention is shown. The multiphase switching power supply includes an n-phase power conversion circuit, where n is an integer greater than or equal to 2. The phase number control method of this embodiment includes controlling the number of operating phases of the multiphase switching power supply based on a first parameter and a load current. The first parameter includes at least one of the input voltage, output voltage, and temperature of the multiphase switching power supply, and the number of operating phases is the number of phases of the power conversion circuit performing power operation. Specifically, the phase number control method of this embodiment may include:

[0055] In step S100, the switching threshold of each adjacent working phase number corresponding to the value of the first parameter sampling signal is obtained based on the first parameter sampling signal characterizing the first parameter.

[0056] In some embodiments, the switching thresholds for each adjacent number of operating phases corresponding to the first parameter sampling signal value (or, in other words, corresponding to the first parameter value) can be obtained based on the first parameter sampling signal and the optimal switching load current information for adjacent operating phases under different first parameter values. The optimal switching load current information is the load current information corresponding to the intersection point of the efficiency curves of adjacent operating phases with the same first parameter value. The optimal switching load current information for adjacent operating phases under different first parameter values ​​represents the optimal switching load current information for adjacent operating phases when the first parameter is equal to two or more different values. For example, the optimal switching load current information includes the optimal switching load current or the optimal switching threshold, where the optimal switching load current is the load current corresponding to the intersection point, and the optimal switching threshold is the load current sampling signal corresponding to the intersection point. See [reference needed] for details. Figure 4 , Figure 4Taking the input voltage Vin of the multiphase switching power supply as an example with the first parameter as the input voltage, the efficiency curves are shown for 1, 2, 3, and 4 operating phases, respectively, under the condition that the input voltage Vin is equal to V1, V2, and V3. The vertical axis of the efficiency curve is efficiency, and the horizontal axis can be either the load current i0 or the load current sampling signal Sio, where i0 is the efficiency. 12_1 I 23_1 I 34_1 These represent the optimal switching load currents for 1-phase to 2-phase, 2-phase to 3-phase, and 3-phase to 4-phase operations when the input voltage Vin = V1, respectively; I 12_2 I 23_2 I 34_2 These represent the optimal switching load currents for 1-phase to 2-phase, 2-phase to 3-phase, and 3-phase to 4-phase operations when the input voltage Vin = V2, respectively; I 12_3 I 23_3 I 34_3 These represent the optimal switching load currents for 1-phase to 2-phase, 2-phase to 3-phase, and 3-phase to 4-phase operations, respectively, when the input voltage Vin = V3. Correspondingly, th 12_1 ,th 23_1 ,th 34_1 These represent the optimal switching thresholds for 1-phase to 2-phase, 2-phase to 3-phase, and 3-phase to 4-phase when the input voltage Vin = V1, respectively. 12_2 ,th 23_2 ,th 34_2 These represent the optimal switching thresholds for 1-phase to 2-phase, 2-phase to 3-phase, and 3-phase to 4-phase respectively, when the input voltage Vin = V2; 12_3 ,th 23_3 ,th 34_3 These represent the optimal switching thresholds for 1-phase to 2-phase, 2-phase to 3-phase, and 3-phase to 4-phase when the input voltage Vin = V3, respectively.

[0057] In step S200, the number of working phases of the multiphase switching power supply is controlled according to the load current sampling signal characterizing the load current and the switching threshold of each adjacent working phase corresponding to the first parameter sampling signal value.

[0058] In some embodiments, the load current sampling signal and the switching threshold of each adjacent working phase corresponding to the first parameter sampling signal value can be compared, and the number of working phases of the multiphase switching power supply can be controlled according to the comparison result.

[0059] Figure 2This diagram illustrates a method for obtaining the switching threshold of each adjacent number of operating phases corresponding to the value of a first parameter sampling signal according to an embodiment of the present invention. In this embodiment, the switching threshold of each adjacent number of operating phases corresponding to the value of the first parameter sampling signal is obtained by looking up a table based on the first parameter sampling signal. Figure 2 Step S100 includes steps S111 and S112, that is, in this embodiment, the method for obtaining the switching threshold of each adjacent number of working phases corresponding to the first parameter sampling signal value includes:

[0060] In step S111, data is stored in the first register based on the optimal switching load current information of adjacent working phases under different sizes of the first parameter;

[0061] In step S112, a lookup instruction is obtained based on the first parameter sampling signal, and data is read from the first register according to the lookup instruction to obtain the switching threshold of each adjacent working phase number corresponding to the value of the first parameter sampling signal.

[0062] In some embodiments, in step S111, the optimal switching load current information for adjacent operating phases under different sizes of the first parameter can be stored in the first register. For example, the optimal switching load current information for adjacent operating phases under different sizes of the first parameter can be stored in the first register. Figure 4 The optimal switching load currents (I) shown in the figure are as follows: 12_1 I 23_1 I 34_1 I 12_2 I 23_2 I 34_2 I 12_3 I 23_3 I 34_3 ) or each optimal switching threshold (th 12_1 ,th 23_1 ,th 34_1 ,th 12_2 ,th 23_2 ,th 34_2 ,th 12_3 ,th 23_3 ,th 34_3 The input voltage is stored in the first register. Accordingly, in step S112, a lookup instruction can be obtained by determining which of V1, V2, and V3 the input voltage value corresponding to the input voltage sampling signal value is closest to. For example, if the input voltage value corresponding to the input voltage sampling signal value is closest to V1, then I is read from the first register. 12_1 I 23_1 I 34_1 or th 12_1 ,th 23_1 ,th 34_1In order to obtain the switching threshold of each adjacent working phase number corresponding to the first parameter sampling signal value.

[0063] When testing efficiency, it is sufficient to test the efficiency curves under two or more different values ​​of the first parameter, for example... Figure 4 Efficiency was tested under three different input voltages (V1, V2, V3). To store more switching load currents or switching thresholds under different values ​​of the first parameter in the first register without increasing efficiency testing costs, making the multiphase switching power supply closer to the true optimal efficiency curve, in some embodiments, step S111 can also be performed by fitting the optimal switching load current information of adjacent operating phases under different values ​​of the first parameter to obtain a fitting formula for each adjacent operating phase. The independent variable of the fitting formula can characterize the information of the first parameter or the first parameter sampling signal, and the dependent variable can characterize the information of the switching load current or the switching threshold of adjacent operating phases. The switching load current or switching threshold of each adjacent operating phase under different values ​​of the first parameter is obtained according to the fitting formula, and data is stored in the first register according to the switching load current or switching threshold of each adjacent operating phase under different values ​​of the first parameter. The switching load current represents the load current corresponding to when the load current sampling signal equals the switching threshold. In some embodiments, the independent variable of the fitting formula includes a first parameter or a first parameter sampling signal, and the dependent variable of the fitting formula includes the switching load current of adjacent operating phases or the switching threshold of adjacent operating phases. For details, please refer to... Figure 5a and Figure 5b , Figure 5a and Figure 5b All based on Figure 4 The obtained fitted curves are illustrated, and all examples are based on linear fitting. Figure 5a The independent variable in each fitting formula is the input voltage Vin, and the dependent variable is the switching load current I of each adjacent operating phase. 12 I 23 I 34 , Figure 5b The independent variable in each fitting formula is the input voltage sampling signal Svin, and the dependent variable is the switching threshold th for each adjacent operating phase. 12 ,th 23 ,th 34 Of course, in other embodiments, the independent variable of the fitting formula can be set to the input voltage, and the dependent variable to the switching threshold of the number of adjacent operating phases; or the independent variable can be the input voltage sampling signal, and the dependent variable can be the switching load current of the number of adjacent operating phases. Figure 5a Taking the fitting formulas shown as examples, substitute the input voltage Vin = V4 into each fitting formula (I 12 =A12 *Vin+B 12 I 23 =A 23 *Vin+B 23 I 34 =A 34 *Vin+B 34 Since V4 is not equal to V1, V2, and V3, the switching load current of each adjacent working phase corresponding to the input voltage Vin = V4 can be obtained and stored in the first register. This allows more switching load currents under different values ​​of the first parameter to be stored in the first register without increasing the efficiency test cost.

[0064] Figure 3 This is a flowchart illustrating a method for obtaining the switching threshold of each adjacent operating phase corresponding to the value of a first parameter sampling signal, according to another embodiment of the present invention. In this embodiment, the switching threshold of each adjacent operating phase corresponding to the value of the first parameter sampling signal is obtained by calculating based on the first parameter sampling signal and the optimal switching load current information of the adjacent operating phases under different values ​​of the first parameter. Figure 3 Step S100 includes steps S121 and S122, that is, in this embodiment, the method for obtaining the switching threshold of each adjacent working phase number corresponding to the first parameter sampling signal value includes:

[0065] In step S121, the optimal switching load current information of adjacent working phases under different sizes of the first parameter is fitted to obtain the fitting formula for each adjacent working phase. The independent variable of the fitting formula can characterize the information of the first parameter or the first parameter sampling signal, and the dependent variable can characterize the information of the switching load current of adjacent working phases or the switching threshold of adjacent working phases.

[0066] For the fitting formula, please refer to [link / reference]. Figure 5a and Figure 5b As for the introduction mentioned above, it will not be repeated here.

[0067] In step S122, the switching threshold of each adjacent working phase corresponding to the value of the first parameter sampling signal is obtained by calculation based on the fitting formula of the first parameter sampling signal and the fitting formula of each adjacent working phase.

[0068] In some embodiments, the first parameter sampling signal can be substituted into the fitting formula corresponding to each adjacent number of working phases to obtain the switching threshold of each adjacent number of working phases corresponding to the value of the first parameter sampling signal. For example, when the independent variable of the fitting formula is the first parameter sampling signal, the first parameter sampling signal can be directly substituted into the fitting formula; when the independent variable of the fitting formula is the first parameter, the quotient of the first parameter sampling signal and the first parameter sampling coefficient can be substituted into the fitting formula, where the first parameter sampling coefficient is the proportionality coefficient between the first parameter sampling signal and the first parameter; when the dependent variable of the fitting formula is the switching threshold of the adjacent number of working phases, the result calculated by substituting the first parameter sampling signal into the fitting formula can be directly used as the switching threshold of the adjacent number of working phases; when the dependent variable of the fitting formula is the switching load current of the adjacent number of working phases, the result calculated by substituting the first parameter sampling signal into the fitting formula can be multiplied by the load current sampling coefficient and used as the switching threshold of the adjacent number of working phases, where the load current sampling coefficient is the proportionality coefficient between the load current sampling signal and the load current.

[0069] In other embodiments, the switching threshold of each adjacent operating phase corresponding to the first parameter sampling signal value can also be calculated based on the first parameter sampling signal, the fitting formula for each adjacent operating phase number, the optimal switching load current information of the adjacent operating phase number when the first parameter or the first parameter sampling signal equals a specific value, and the specific value. In one embodiment, using Figure 5b Taking the fitting formula corresponding to the shown fitting curve as an example, it can be based on the input voltage sampling signal Svin and the fitting formula corresponding to each adjacent working phase (th). 12 =a 12 *Svin+b 12 ,th 23 =a 23 *Svin+b 23 ,th 34 =a 34 *Svin+b 34 When the input voltage sampling signal Svin equals a specific value (e.g., S...), V2 The optimal switching threshold for the number of adjacent working phases (th) 12_2 ,th 23_2 ,th 34_2 (at least one of them), and the specific value S V2 The switching threshold for each adjacent operating phase corresponding to the first parameter sampling signal value is obtained by calculation. For example, when the input voltage sampling signal Svin equals a specific value (e.g., S... V2 The optimal switching threshold for phase 1 to phase 2 at this time is th. 12_2 When performing calculations, one can calculate th. 12_2 +a12 *(Svin-S V2 The value of ) is used to obtain the 1-phase to 2-phase switching threshold corresponding to the first parameter sampling signal value; when the input voltage sampling signal Svin equals S V2 The optimal 2-phase to 3-phase switching threshold th 23_2 When performing calculations, by calculating th 23_2 +a 23 *(Svin-S V2 The value of ) is used to obtain the 2-phase to 3-phase switching threshold corresponding to the value of the first parameter sampled signal.

[0070] In summary, compared with the prior art, the phase control method provided by the present invention allows the switching threshold to change with the sampling signal of the first parameter (or the switching threshold to change with the first parameter). The number of working phases of the multiphase switching power supply is controlled not only by the load current but also by the first parameter, which makes the switching threshold closer to the optimal switching threshold, or even equal to the optimal switching threshold. This allows the multiphase switching power supply to operate closer to the true optimal efficiency curve, or even operate on the true optimal efficiency curve, further improving the efficiency of the multiphase switching power supply.

[0071] In one embodiment, a first battery pack provides an input voltage to the multiphase switching power supply. The first battery pack includes one or more batteries. The input voltage provided by the first battery pack varies with usage and power level. Setting the first parameter to include the input voltage of the multiphase switching power supply and the switching threshold varying with the input voltage can improve the efficiency of the multiphase switching power supply and save battery consumption.

[0072] refer to Figure 6 The multiphase switching power supply provided in this embodiment of the invention receives an input voltage Vin and provides an output voltage Vout and a load current io to the load. The multiphase switching power supply includes n-phase power conversion circuits 301-30n, a control circuit 10, and an output capacitor Cout, where n is an integer greater than or equal to 2. The n-phase power conversion circuits 301-30n are connected in parallel between the input voltage Vin of the multiphase switching power supply and the load. The control circuit 10 controls the number of operating phases of the multiphase switching power supply according to a first parameter and the load current. The first parameter includes at least one of the input voltage Vin, the output voltage Vout, and the temperature of the multiphase switching power supply. The number of operating phases refers to the number of phases of the power conversion circuits performing power operation. This application does not limit the topology of the power conversion circuits 301-30n. Figure 6Using only a buck topology as an example, the specific circuit structure of the power conversion circuit 301 is shown, including a first switch T1 and a second switch T2 connected between the input voltage Vin and ground, and an inductor L01 connected between the common terminal of the first switch T1 and the second switch T2 and the output terminal.

[0073] Figure 6 A schematic diagram of the circuit structure of a multiphase switching power supply according to an embodiment of the present invention is shown. Figure 6 Taking the input voltage Vin of the multiphase switching power supply as an example, with the first parameter being... Figure 6 In the illustrated embodiment, the control circuit 10 controls the number of operating phases of the multiphase switching power supply based on the input voltage Vin and the load current io. Specifically, the control circuit 10 controls the number of operating phases of the multiphase switching power supply based on the input voltage sampling signal Svin, which characterizes the input voltage Vin, and the load current sampling signal Sio, which characterizes the load current io. The control circuit 10 includes a switching threshold generation unit 11 and a phase number control signal generation unit 12. The switching threshold generation unit 11 outputs a switching threshold th corresponding to the input voltage sampling signal value (or, in other words, corresponding to the input voltage value) for each adjacent operating phase based on the input voltage sampling signal Svin. 12 ,th 23 …th (n-1)n The phase number control signal generation unit 12 receives the load current sampling signal Sio and the switching threshold of each adjacent working phase corresponding to the input voltage sampling signal value output by the switching threshold generation unit 11, and outputs a phase number control signal according to the load current sampling signal and the switching threshold of each adjacent working phase corresponding to the input voltage sampling signal value; the control circuit 10 controls the number of working phases of the multi-phase switching power supply according to the phase number control signal. In addition, the control circuit 10 also includes a PWM signal generation module 13, n drive circuits 201-20n, an input voltage sampling circuit (not shown in the figure), and a load current sampling circuit (not shown in the figure). The input voltage sampling circuit generates the input voltage sampling signal Svin. The load current sampling circuit generates the load current sampling signal Sio. The PWM signal generation module 13 generates n-phase PWM signals PWM1 to PWMn. Each drive circuit receives a PWM signal and controls the switching transistors in the corresponding power conversion circuit to turn on and off according to the received PWM signal. In one embodiment, such as... Figure 6As shown, the PWM signal generation module 13 receives the phase number control signal and controls whether the PWM signals PWM1 to PWMn are in a high-impedance state according to the phase number control signal, so as to control whether each power conversion circuit works (i.e., whether it operates with power). When the PWM signal is in a high-impedance state, the power conversion circuit of the corresponding phase is controlled to not work; when the PWM signal is not in a high-impedance state, the power conversion circuit of the corresponding phase is controlled to work. In another embodiment, the PWM signal generation module 13 can also be configured not to receive the phase number control signal, but to control whether each drive circuit 201-20n is enabled (not shown in the figure) according to the phase number control signal, so as to control whether the power conversion circuit of the corresponding phase works. In one embodiment, the phase number control signal generation unit 12 can compare the load current sampling signal with the switching threshold of each adjacent working phase corresponding to the input voltage sampling signal value, and output the phase number control signal according to the comparison result. For example, the phase number control signal generation unit 12 includes comparators U0 to U(n-1). The first input terminals of comparators U0 to U(n-1) all receive load current sampling signals, and the second input terminals respectively receive the switching threshold th of each adjacent working phase number corresponding to the input voltage sampling signal value. 12 ,th 23 …th (n-1)n The output terminals respectively output comparison signals L 12 L 23 …L (n-1)n Each comparison signal is used as the phase number control signal.

[0074] Figure 7 It shows according to Figure 6 A schematic diagram of the circuit structure of the first embodiment of the switching threshold generation unit is shown below. In this embodiment, the switching threshold generation unit 11 includes an instruction generation unit 111 and a first register 112. The instruction generation unit receives an input voltage sampling signal Svin and generates a lookup table instruction based on the input voltage sampling signal value. The switching threshold generation unit 111 reads data from the first register 112 according to the lookup table instruction to obtain the switching threshold th for each adjacent number of working phases corresponding to the input voltage sampling signal value. 12 ,th 23 …th (n-1)n , among which th 12 The 1-phase to 2-phase switching threshold represented by th 23 The 2-phase to 3-phase switching threshold represented by th (n-1)nThe (n-1) phase to n phase switching threshold is represented by the data stored in the first register 112, which is obtained based on the optimal switching load current information of the number of adjacent operating phases under different input voltage values. For example, when the data stored in the first register 112 is the optimal switching threshold, the optimal switching threshold corresponding to the number of adjacent operating phases corresponding to the input voltage sampling signal value can be read from the first register 112 and output as the switching threshold of the number of adjacent operating phases corresponding to the input voltage sampling signal value. When the data stored in the first register 112 is the optimal switching load current, the switching threshold generation unit 11 further includes a signal processing unit (not shown in the figure). This signal processing unit processes the optimal switching load current of the number of adjacent operating phases corresponding to the input voltage sampling signal value read from the first register 112 to output the switching threshold of the number of adjacent operating phases corresponding to the input voltage sampling signal value.

[0075] Figure 8 It shows according to Figure 6 A schematic diagram of the circuit structure of the switching threshold generation unit in a second embodiment is provided. In this embodiment, the switching threshold generation unit 11 includes a first calculation unit 113. The first calculation unit 113 receives an input voltage sampling signal Svin and calculates the switching threshold of each adjacent operating phase number according to the input voltage sampling signal Svin and the fitting formula corresponding to each adjacent operating phase number, so as to output the switching threshold of each adjacent operating phase number corresponding to the input voltage sampling signal value. The fitting formula corresponding to each adjacent operating phase number is a formula obtained by fitting the optimal switching load current information of the adjacent operating phase number under different input voltage values. The independent variable of the fitting formula can characterize the information of the input voltage or the input voltage sampling signal, and the dependent variable can characterize the information of the switching load current or the switching threshold of the adjacent operating phase number. In some embodiments, the first calculation unit 113 can substitute the input voltage sampling signal into the fitting formula corresponding to each adjacent operating phase number to output the switching threshold of each adjacent operating phase number corresponding to the input voltage sampling signal value. In other embodiments, the first calculation unit 113 may also perform calculations based on the input voltage sampling signal, the fitting formula corresponding to each adjacent number of working phases, the optimal switching load current information of the adjacent number of working phases when the input voltage signal or the input voltage sampling signal is equal to a specific value, and the specific value, to output the switching threshold of each adjacent number of working phases corresponding to the input voltage sampling signal value.

[0076] Figure 9 It shows according to Figure 6 A schematic diagram of the circuit structure of the switching threshold generation unit in the third embodiment. (Compared to...) Figure 8Compared to the switching threshold generation unit shown, the switching threshold generation unit 11 in this embodiment further includes a second register 114. The first calculation unit 113 reads data from the second register 114 to obtain fitting parameters of the fitting formula corresponding to each adjacent number of working phases; and / or, the optimal switching load current information of the adjacent number of working phases when the input voltage signal or the input voltage sampling signal is equal to a specific value. The following uses... Figure 5b The fitting formula corresponding to the shown fitting curve will be used as an example for explanation. In some embodiments, the fitting parameter 'a' of the fitting formula corresponding to each adjacent number of working phases can be stored in the second register 114. 12 b 12 a 23 b 23 a 34 b 34 The first calculation unit 113 calculates the input voltage sampling signal Svin and the fitting parameters a read from the second register 114. 12 b 12 a 23 b 23 a 34 b 34 The calculation is performed using fitting formulas corresponding to the number of adjacent operating phases. In some embodiments, the optimal switching threshold for the number of adjacent operating phases when the input voltage sampling signal equals a specific value can also be stored in the second register 114. The first calculation unit 113 performs the calculation based on the input voltage sampling signal Svin, the fitting formulas corresponding to the number of adjacent operating phases, and the data read from the second register 114. In one embodiment, the specific value can also be stored in the second register 114 at the same time. In another embodiment, some or all of the fitting parameters of the fitting formulas corresponding to the number of adjacent operating phases can also be stored in the second register 114 at the same time.

[0077] It should be noted that, for ease of understanding, this application... Figures 4 to 9 The examples all use the input voltage Vin of the multiphase switching power supply as the first parameter. Based on the above description, those skilled in the art can easily obtain a scheme where the first parameter is the output voltage Vout or temperature of the multiphase switching power supply, as well as a scheme where the first parameter includes two or three of the input voltage Vin, output voltage Vout, and temperature of the multiphase switching power supply. These will not be elaborated further here.

[0078] It should also be noted that this application does not limit the data type of the switching threshold; it can be digital or analog. This application does not limit the form of the fitting function used to obtain the fitting formula for each adjacent working phase; in cases where... Figure 5a and Figure 5bIn the illustrated embodiment, a relatively simple linear fitting is used, resulting in a fitting formula in the form of a linear function. In other embodiments, nonlinear fitting can also be used to obtain fitting formulas in the form of polynomial functions, exponential functions, logarithmic functions, etc.

[0079] In summary, the embodiments of the present invention can control the number of operating phases of the multiphase switching power supply according to the first parameter and the load current. Compared with the prior art which only controls the number of operating phases of the multiphase switching power supply according to the load current, the multiphase switching power supply can operate closer to the true optimal efficiency curve, or even operate on the true optimal efficiency curve, thereby further improving the efficiency of the multiphase switching power supply.

[0080] The embodiments described above do not constitute a limitation on the scope of protection of this technical solution. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the above embodiments should be included within the scope of protection of this technical solution.

Claims

1. A phase number control method for a multiphase switching power supply, the multiphase switching power supply comprising an n-phase power conversion circuit, wherein n is an integer greater than or equal to 2, characterized in that, include: The number of operating phases of the multiphase switching power supply is controlled according to the first parameter and the load current. The first parameter includes at least one of the input voltage, output voltage, and temperature of the multiphase switching power supply, and the number of operating phases is the number of phases of the power conversion circuit for power operation.

2. The phase number control method according to claim 1, characterized in that, include: The switching threshold of each adjacent working phase number corresponding to the value of the first parameter sampling signal is obtained based on the first parameter sampling signal characterizing the first parameter. The number of operating phases of the multiphase switching power supply is controlled based on the load current sampling signal characterizing the load current and the switching threshold of each adjacent operating phase corresponding to the first parameter sampling signal value.

3. The phase number control method according to claim 2, characterized in that, Based on the first parameter sampling signal and the optimal switching load current information of the number of adjacent working phases under different values ​​of the first parameter, the switching threshold of each number of adjacent working phases corresponding to the value of the first parameter sampling signal is obtained. The optimal switching load current information is the load current information corresponding to the intersection point of the efficiency curves of adjacent operating phases with the same first parameter.

4. The phase number control method according to claim 3, characterized in that, Based on the optimal switching load current information of adjacent working phases under different sizes of the first parameter, data is stored in the first register; A lookup instruction is obtained based on the first parameter sampling signal, and data is read from the first register based on the lookup instruction to obtain the switching threshold of each adjacent working phase corresponding to the value of the first parameter sampling signal.

5. The phase number control method according to claim 4, characterized in that, The optimal switching load current information of adjacent working phases under different sizes of the first parameter is fitted to obtain the fitting formula corresponding to each adjacent working phase. The independent variable of the fitting formula can characterize the information of the first parameter or the first parameter sampling signal, and the dependent variable can characterize the information of the switching load current or switching threshold of adjacent working phases. The switching load current or switching threshold of each adjacent working phase under different sizes of the first parameter is obtained according to the fitting formula of each adjacent working phase, and the data is stored in the first register according to the switching load current or switching threshold of each adjacent working phase under different first parameters.

6. The phase number control method according to claim 3, characterized in that, The optimal switching load current information of adjacent working phases under different sizes of the first parameter is fitted to obtain the fitting formula corresponding to each adjacent working phase. The independent variable of the fitting formula can characterize the information of the first parameter or the first parameter sampling signal, and the dependent variable can characterize the information of the switching load current of adjacent working phases or the switching threshold of adjacent working phases. Based on the first parameter sampling signal and the fitting formula of each adjacent working phase, the switching threshold of each adjacent working phase corresponding to the first parameter sampling signal value is obtained by calculation.

7. The phase number control method according to claim 6, characterized in that, Based on the first parameter sampling signal, the fitting formula for each adjacent number of working phases, the optimal switching load current information of the adjacent number of working phases when the first parameter or the first parameter sampling signal is equal to a specific value, and the specific value, the switching threshold of each adjacent number of working phases corresponding to the value of the first parameter sampling signal is obtained by calculation.

8. The phase number control method according to any one of claims 5-7, characterized in that, Linear fitting is performed based on the optimal switching load current information of adjacent operating phases under different sizes of the first parameter to obtain the fitting formula for each adjacent operating phase.

9. The phase number control method according to claim 2, characterized in that, The load current sampling signal is compared with the switching threshold of each adjacent working phase corresponding to the first parameter sampling signal value, and the number of working phases of the multiphase switching power supply is controlled according to the comparison result.

10. The phase number control method according to claim 1, characterized in that, The first battery pack provides the input voltage to the multiphase switching power supply, and the first parameter includes the input voltage.

11. A control circuit for a multiphase switching power supply, the multiphase switching power supply comprising an n-phase power conversion circuit, wherein n is an integer greater than or equal to 2, characterized in that, The control circuit controls the number of working phases of the multiphase switching power supply according to the first parameter and the load current. The first parameter includes at least one of the input voltage, output voltage, and temperature of the multiphase switching power supply, and the number of operating phases is the number of phases of the power conversion circuit for power operation.

12. The control circuit according to claim 11, characterized in that, The control circuit includes: The switching threshold generation unit outputs a switching threshold for each adjacent number of working phases corresponding to the value of the first parameter sampling signal, based on the first parameter sampling signal characterizing the first parameter. The phase number control signal generation unit receives a load current sampling signal characterizing the load current, and receives the switching threshold of each adjacent working phase number corresponding to the first parameter sampling signal value output by the switching threshold generation unit, and outputs a phase number control signal according to the load current sampling signal and the switching threshold of each adjacent working phase number corresponding to the first parameter sampling signal value. The control circuit controls the number of operating phases of the multiphase switching power supply according to the phase number control signal.

13. The control circuit according to claim 12, characterized in that, The switching threshold generation unit obtains the switching threshold of each adjacent working phase corresponding to the value of the first parameter sampling signal based on the first parameter sampling signal and the optimal switching load current information of the adjacent working phases under different values ​​of the first parameter. The optimal switching load current information is the load current information corresponding to the intersection point of the efficiency curves of adjacent operating phases with the same first parameter.

14. The control circuit according to claim 13, characterized in that, The switching threshold generation unit includes an instruction generation unit and a first register. The instruction generation unit receives the first parameter sampling signal and generates a lookup instruction based on the value of the first parameter sampling signal; The switching threshold generation unit reads data from the first register according to the lookup instruction to obtain the switching threshold of each adjacent working phase number corresponding to the first parameter sampling signal value; The data stored in the first register is obtained based on the optimal switching load current information of adjacent working phases under different sizes of the first parameter.

15. The control circuit according to claim 13, characterized in that, The switching threshold generation unit includes a first calculation unit. The first calculation unit receives the first parameter sampling signal and performs calculations based on the first parameter sampling signal and the fitting formula of each adjacent working phase number to output the switching threshold of each adjacent working phase number corresponding to the value of the first parameter sampling signal. The fitting formula for each adjacent number of working phases is a formula obtained by fitting the optimal switching load current information of adjacent working phases under different sizes of the first parameter. The independent variable of the fitting formula can characterize the information of the first parameter or the first parameter sampling signal, and the dependent variable can characterize the information of the switching load current of adjacent working phases or the switching threshold of adjacent working phases.

16. The control circuit according to claim 15, characterized in that, The switching threshold generation unit also includes a second register. The first calculation unit reads data from the second register to obtain the fitting parameters of the fitting formula corresponding to each adjacent working phase number; and / or, The optimal switching load current information for the number of adjacent working phases when the first parameter or the first parameter sampling signal is equal to a specific value.

17. A multiphase switching power supply, the multiphase switching power supply comprising an n-phase power conversion circuit, characterized in that, The control circuit as described in any one of claims 11-16, or the phase number control method as described in any one of claims 1-10, is used to control the number of working phases of the multiphase switching power supply.

Images