A multi-phase switching circuit and a thermal balance adjustment method thereof

Abstract

The present invention discloses a multi-phase switch circuit and a heat balance adjustment method thereof, wherein the multi-phase switch circuit includes an n-phase switch circuit and a k-phase heat balance adjustment circuit, and if the heat dissipation condition of the m-phase switch circuit is better than that of the first-phase switch circuit, the m-phase heat balance adjustment circuit can adjust the inductance current of the m-phase switch circuit to increase relative to the inductance current of the first-phase switch circuit; if the heat dissipation condition of the m-phase switch circuit is worse than that of the first-phase switch circuit, the m-phase heat balance adjustment circuit can adjust the inductance current of the m-phase switch circuit to decrease relative to the inductance current of the first-phase switch circuit; wherein n is an integer greater than 1, k is an integer from 1 to (n-1), and m is an integer from 2 to n. The present application can adjust the relative size of the current of each phase switch circuit according to the actual heat dissipation condition of each phase switch circuit of the multi-phase switch circuit to achieve temperature balance.

Description

Technical Field

[0001] The present invention relates to the technical field of power electronics, and in particular to a multi-phase switch circuit and a thermal balance regulating method thereof. Background Art

[0002] The parallel connection of multi-phase switch circuits can meet the needs of high current applications. By controlling the staggered conduction of each phase switch circuit, the input and output current ripples can be reduced while reducing the inductance of the single-phase switch circuit, and the output capacitance can be effectively reduced. In the prior art, the output currents of each phase switch circuit are generally set to be the same to achieve uniform distribution of power and heat. Ideally, if the output currents of each phase switch circuit are the same, the heating conditions at the physical positions of each phase switch circuit are the same, and accordingly, the temperatures at the physical positions of each phase switch circuit are the same. However, the actual situation is that due to external factors or layout influences, the temperatures of each phase switch circuit are unequal. For example, the phase switch circuits are located at different positions on the circuit board, and the different distances from the cooling fan at different positions will cause differences in heat dissipation. If the output currents of each phase switch circuit are still controlled to be the same, then the position with poor heat dissipation will heat up seriously. Summary of the invention

[0003] In view of this, an object of the present invention is to provide a multi-phase switching circuit and a method for adjusting thermal balance thereof, so as to solve the technical problem of serious heating at positions with poor heat dissipation in the multi-phase switching circuit in the prior art.

[0004] The technical solution of the present invention is, in a first aspect, to provide a multi-phase switching circuit, the multi-phase switching circuit comprising an n-phase switching circuit and a k-phase thermal balance regulating circuit, wherein:

[0005] The m-phase thermal balance adjustment circuit adjusts the inductor current of the m-phase switch circuit according to the heat dissipation condition of the m-phase switch circuit and the heat dissipation condition of the first-phase switch circuit.

[0006] so that the inductor current of the m-th phase switch circuit matches the heat dissipation condition of the m-th phase switch circuit;

[0007] Herein, n is an integer greater than 1, k is an integer from 1 to (n-1), and m is an integer from 2 to n.

[0008] Optionally, if the heat dissipation condition of the m-phase switch circuit is better than that of the first-phase switch circuit, the m-phase heat balance adjustment circuit may adjust the inductance current of the m-phase switch circuit to increase relative to the inductance current of the first-phase switch circuit;

[0009] If the heat dissipation condition of the m-phase switching circuit is worse than that of the 1st-phase switching circuit, the m-phase thermal balance adjustment circuit can adjust the inductance current of the m-phase switching circuit to be smaller than the inductance current of the 1st-phase switching circuit.

[0010] Optionally, if the heat dissipation condition of the m-th phase switch circuit is better than that of the 1st phase switch circuit, the m-th phase heat balance adjustment circuit may adjust the average value of the m-th sampling signal to be greater than the average value of the 1st sampling signal;

[0011] If the heat dissipation condition of the m-th phase switch circuit is worse than that of the first phase switch circuit, the m-th phase heat balance adjustment circuit may adjust the average value of the m-th sampling signal to be smaller than the average value of the first sampling signal;

[0012] The first sampling signal represents the inductor current of the first phase switch circuit, and the mth sampling signal represents the inductor current of the mth phase switch circuit.

[0013] Optionally, the m-th phase thermal balance adjustment circuit includes:

[0014] an m-th target value generating circuit, receiving the average value of the first sampling signal to output the m-th target value, and adjusting the m-th target value according to the heat dissipation conditions of the m-th phase switching circuit and the first phase switching circuit; if the heat dissipation condition of the m-th phase switching circuit is better than that of the first phase switching circuit, the m-th target value can be adjusted to be greater than the average value of the first sampling signal; if the heat dissipation condition of the m-th phase switching circuit is worse than that of the first phase switching circuit, the m-th target value can be adjusted to be less than the average value of the first sampling signal;

[0015] The mth sampling signal processing circuit receives the mth sampling signal and the mth target value to output an mth processed sampling signal.

[0016] Optionally, the mth target value generating circuit includes:

[0017] A programmable control circuit, which can be programmed according to the heat dissipation conditions of the m-phase switch circuit and the first-phase switch circuit to set the control signal output by the programmable control circuit;

[0018] The signal processing circuit receives the average value of the first sampling signal and the control signal to output the mth target value.

[0019] Optionally, the signal processing circuit includes a first operational amplifier and a resistor array module,

[0020] The first input terminal of the first operational amplifier receives the average value of the first sampling signal; the resistor array module is connected to the second input terminal of the first operational amplifier and the output terminal of the first operational amplifier, and the output terminal of the resistor array module outputs the mth target value;

[0021] The control signal controls a connection scheme among the resistor array module, the second input terminal of the first operational amplifier, the output terminal of the first operational amplifier, and the output terminal of the resistor array module.

[0022] Optionally, the mth sampling signal processing circuit includes:

[0023] an m-th averaging circuit, receiving the m-th sampling signal, and performing an averaging operation to output an average value of the m-th sampling signal;

[0024] A second operational amplifier, having a first input terminal receiving the mth target value, a second input terminal receiving the average value of the mth sampling signal, and an output terminal outputting an error amplified signal;

[0025] A subtractor, having a first input terminal receiving the mth sampling signal and a second input terminal receiving the error amplified signal, performs a subtraction operation on the mth sampling signal and the error amplified signal to output the mth processed sampling signal.

[0026] Optionally, the multi-phase switching circuit further includes a first switching signal generating circuit and an mth switching signal generating circuit,

[0027] The first switch signal generating circuit receives the first sampling signal and the first upper limit voltage to output the first phase switch signal; the mth switch signal generating circuit receives the mth processed sampling signal and the first upper limit voltage to output the mth phase switch signal; wherein the first upper limit voltage controls the peak values ​​of the first sampling signal and the mth processed sampling signal;

[0028] The first phase switch signal is used to control the on and off of the main switch tube of the first phase switch circuit; the mth phase switch signal is used to control the on and off of the main switch tube of the mth phase switch circuit.

[0029] Optionally, if the heat dissipation condition of the m-phase switching circuit is better than that of the 1st-phase switching circuit, the m-phase thermal balance regulation circuit can set the m-th upper limit voltage to be greater than the first upper limit voltage; if the heat dissipation condition of the m-phase switching circuit is worse than that of the 1st-phase switching circuit, the m-phase thermal balance regulation circuit can set the m-th upper limit voltage to be less than the first upper limit voltage.

[0030] Optionally, the multi-phase switching circuit further includes a first switching signal generating circuit and an mth switching signal generating circuit,

[0031] The first switch signal generating circuit receives the first sampling signal representing the inductor current of the first phase switch circuit and the first upper limit voltage to output the first phase switch signal; the mth switch signal generating circuit receives the mth sampling signal representing the inductor current of the mth phase switch circuit and the mth upper limit voltage to output the mth phase switch signal; wherein the first upper limit voltage controls the peak value of the first sampling signal, and the mth upper limit voltage controls the peak value of the mth sampling signal;

[0032] The first phase switch signal is used to control the on and off of the main switch tube of the first phase switch circuit; the mth phase switch signal is used to control the on and off of the main switch tube of the mth phase switch circuit.

[0033] On the other hand, the present invention further provides a method for thermally balancing a multi-phase switch circuit, wherein the multi-phase switch circuit includes an n-phase switch circuit, and the method for thermally balancing includes:

[0034] If the heat dissipation condition of the m-phase switch circuit is better than that of the first-phase switch circuit, the inductor current of the m-phase switch circuit may be adjusted to increase relative to the inductor current of the first-phase switch circuit;

[0035] If the heat dissipation condition of the m-phase switch circuit is worse than that of the first-phase switch circuit, the inductor current of the m-phase switch circuit may be adjusted to be smaller than the inductor current of the first-phase switch circuit;

[0036] Herein, n is an integer greater than 1, and m is an integer from 2 to n.

[0037] Optionally, the thermal balance adjustment method further comprises:

[0038] If the heat dissipation condition of the m-th phase switch circuit is better than that of the 1st phase switch circuit, the average value of the m-th sampling signal can be adjusted to be greater than the average value of the 1st sampling signal;

[0039] If the heat dissipation condition of the m-th phase switch circuit is worse than that of the 1st phase switch circuit, the average value of the m-th sampling signal may be adjusted to be smaller than the average value of the 1st sampling signal;

[0040] The first sampling signal represents the inductor current of the first phase switch circuit, and the mth sampling signal represents the inductor current of the mth phase switch circuit.

[0041] Optionally, the method for adjusting the average value of the mth sampling signal further comprises:

[0042] If the heat dissipation condition of the m-th phase switch circuit is better than that of the 1st phase switch circuit, the m-th target value may be set to be greater than the average value of the 1st sampling signal; if the heat dissipation condition of the m-th phase switch circuit is worse than that of the 1st phase switch circuit, the m-th target value may be set to be less than the average value of the 1st sampling signal;

[0043] and making the average value of the mth sampling signal equal to the mth target value;

[0044] And obtain the mth processed sampling signal according to the mth sampling signal and the mth target value.

[0045] Optionally, the thermal balance adjustment method further includes:

[0046] Obtaining a first-phase switching signal according to the first sampling signal and a first upper limit voltage; obtaining an m-phase switching signal according to the m-th processed sampling signal and the first upper limit voltage; wherein the first upper limit voltage controls the peak values ​​of the first sampling signal and the m-th processed sampling signal;

[0047] The first phase switch signal is used to control the on and off of the main switch tube of the first phase switch circuit; the mth phase switch signal is used to control the on and off of the main switch tube of the mth phase switch circuit.

[0048] Optionally, the thermal balance adjustment method further comprises:

[0049] If the heat dissipation condition of the m-th phase switch circuit is better than that of the first phase switch circuit, the m-th upper limit voltage may be set to be greater than the first upper limit voltage; if the heat dissipation condition of the m-th phase switch circuit is worse than that of the first phase switch circuit, the m-th upper limit voltage may be set to be less than the first upper limit voltage;

[0050] The first upper limit voltage is used to control the peak value of the inductor current of the first phase switching circuit; the mth upper limit voltage is used to control the peak value of the inductor current of the mth phase switching circuit.

[0051] Compared with the prior art, the circuit structure of the present invention has the following advantages: the current of the switch circuit at a position with good heat dissipation conditions in the multi-phase switch circuit can be increased, and the current of the switch circuit at a position with good heat dissipation conditions can be reduced, thereby achieving temperature balance. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 A schematic diagram of the circuit principle of a multi-phase switch circuit according to a first embodiment of the present invention;

[0053] Figure 2 A schematic diagram of the circuit structure of an embodiment of the m-th phase thermal balance regulating circuit of the first embodiment of the present invention;

[0054] Figure 3 FIG. 1 is a circuit structure diagram of an embodiment of the first averaging circuit of the first embodiment of the present invention;

[0055] Figure 4a1 is a circuit structure diagram of an embodiment of the m-th phase thermal balance adjustment circuit of the first embodiment of the present invention when the m-th phase switch circuit has a better heat dissipation condition than the first phase switch circuit;

[0056] Figure 4b Based on Figure 4a The first upper limit voltage Vc1, the first sampling signal CS1, the mth processed sampling signal CSm_O, the mth sampling signal CSm, the first phase switch circuit inductor current i L1 and the inductor current i of the m-phase switching circuit Lm Waveform diagram of ;

[0057] Figure 5a 1 is a circuit structure diagram of an embodiment of the m-th phase thermal balance adjustment circuit of the first embodiment of the present invention when the heat dissipation condition of the m-th phase switch circuit is worse than that of the first phase switch circuit;

[0058] Figure 5b Based on Figure 5a The first upper limit voltage Vc1, the first sampling signal CS1, the mth processed sampling signal CSm_O, the mth sampling signal CSm, the first phase switch circuit inductor current i L1 and the inductor current i of the m-phase switching circuit Lm Waveform diagram of ;

[0059] Figure 6 A schematic diagram of the circuit principle of a multi-phase switch circuit according to a second embodiment of the present invention;

[0060] Figure 7 A circuit structure diagram of an embodiment of the m-th phase thermal balance adjustment circuit of the second embodiment of the present invention

[0061] Figure 8a is a circuit structure diagram of an embodiment of the m-th phase thermal balance adjustment circuit of the second embodiment of the present invention when the m-th phase switch circuit has a better heat dissipation condition than the first phase switch circuit;

[0062] Figure 8b Based on Figure 8a The first upper limit voltage Vc1, the mth upper limit voltage Vcm, the first sampling signal CS1, the mth sampling signal CSm, the first phase switch circuit inductor current i L1 and the inductor current i of the m-phase switching circuit Lm Waveform diagram of ;

[0063] Figure 9a is a circuit structure diagram of an embodiment of the m-th phase thermal balance adjustment circuit of the second embodiment of the present invention when the heat dissipation condition of the m-th phase switch circuit is worse than that of the first phase switch circuit;

[0064] Figure 9b Based on Figure 9a The first upper limit voltage Vc1, the mth upper limit voltage Vcm, the first sampling signal CS1, the mth sampling signal CSm, the first phase switch circuit inductor current i L1 and the inductor current i of the m-phase switching circuit Lm Schematic diagram of the waveform. DETAILED DESCRIPTION

[0065] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings, but the present invention is not limited to these embodiments. The present invention covers any substitution, modification, equivalent method and scheme made within the spirit and scope of the present invention.

[0066] In order to make the public have a thorough understanding of the present invention, specific details are described in detail in the following preferred embodiments of the present invention, but those skilled in the art can fully understand the present invention without these detailed descriptions.

[0067] The present invention is described in more detail in the following paragraphs by way of example with reference to the accompanying drawings. It should be noted that the accompanying drawings are all simplified and not in exact proportion, and are only used for the purpose of conveniently and clearly assisting in explaining the embodiments of the present invention.

[0068] like Figure 1 As shown, the multi-phase switch circuit of the first embodiment of the present invention includes an n-phase switch circuit 10, an inductor current sampling circuit 20, an n-1-phase thermal balance adjustment circuit 30, a first switch signal generating circuit 40 and an m-th switch signal generating circuit 41, wherein n is an integer greater than 1, and m is an integer from 2 to n. For example, the inductor current sampling circuit 20 includes n sampling resistors Rcs1, Rcs2...Rcsn with equal resistance values, wherein the first end of the j-th sampling resistor Rcsj receives the inductor current i of the j-th switch circuit. Lj, the second end is connected to the common mode voltage VCM, and the first end of the j-th sampling resistor Rcsj is used as the output end to output the j-th sampling signal CSj, where j is an integer from 1 to n. The m-th phase thermal balance adjustment circuit 30 receives the m-th sampling signal CSm, and can adjust the m-th sampling signal CSm according to the heat dissipation condition of the m-th phase switch circuit and the heat dissipation condition of the first phase switch circuit, and output the m-th processed sampling signal CSm_O. The first switch signal generating circuit 40 receives the first sampling signal CS1 and the first upper limit voltage Vc1 to output the first phase switch signal PWM1; the m-th switch signal generating circuit 41 receives the m-th processed sampling signal CSm_O and the first upper limit voltage Vc1 to output the m-th phase switch signal PWMm; wherein the first upper limit voltage Vc1 controls the peak values ​​of the first sampling signal CS1 and the m-th processed sampling signal CSm_O. The j-phase switch circuit 10 receives the j-phase switch signal PWMj, and the j-phase switch signal PWMj is used to control the on and off of the main switch tube of the j-phase switch circuit 10. If the j-phase switch circuit 10 also includes a synchronous rectifier tube, the j-phase switch signal PWMj controls the on and off of the main switch tube and the synchronous rectifier tube of the j-phase switch circuit 10. The multi-phase switch circuit of this embodiment also includes a first upper limit voltage generating circuit 50, and the first upper limit voltage generating circuit 50 performs compensation operation according to the error between the output feedback signal FB of the multi-phase switch circuit and the reference voltage Vref to output the first upper limit voltage Vc1. For example, the first upper limit voltage generating circuit 50 includes an error amplifier U00 and a compensation circuit 501. The error amplifier U00 receives the feedback voltage FB and the reference voltage Vref for operational amplification, and the output signal of the error amplifier U00 is processed by the compensation circuit 501 to obtain the first upper limit voltage Vc1.

[0069] In this embodiment, if the heat dissipation condition of the m-phase switch circuit is better than that of the first-phase switch circuit, the m-phase thermal balance adjustment circuit 30 can adjust the average value of the m-th sampling signal Csm to be greater than the average value of the first sampling signal Cs1; if the heat dissipation condition of the m-phase switch circuit is worse than that of the first-phase switch circuit, the m-phase thermal balance adjustment circuit 30 can adjust the average value of the m-th sampling signal Csm to be less than the average value of the first sampling signal Cs1. Thus, if the heat dissipation condition of the m-phase switch circuit is better than that of the first-phase switch circuit, the inductor current i of the m-phase switch circuit can be adjusted. Lm With respect to the first phase switch circuit inductor current i L1 If the heat dissipation condition of the m-phase switching circuit is worse than that of the 1st-phase switching circuit, the inductor current i of the m-phase switching circuit can be adjusted Lm With respect to the first phase switch circuit inductor current i L1It can be understood that in this embodiment, the multi-phase switch circuit includes n-1 phase thermal balance adjustment circuits 30, and in other embodiments, it can also include k-phase thermal balance adjustment circuits 30, where k is an integer from 1 to (n-1).

[0070] It should be noted that the 1st phase or the mth phase in the present application is for the convenience of description and does not limit the specific position of the phase. The 1st phase can be one of the n phases, and the mth phase can be another phase among the n phases. The 1st phase serves as the basis for adjusting the other phases.

[0071] In one embodiment, Figure 2 As shown, the m-th phase thermal balance adjustment circuit 30 includes an m-th target value generating circuit 301 and an m-th sampling signal processing circuit 302. The m-th target value generating circuit 301 receives the average value CS1′ of the first sampling signal to output the m-th target value Vm, and can adjust the size of the m-th target value Vm according to the heat dissipation conditions of the m-th phase switching circuit and the first phase switching circuit. The m-th sampling signal processing circuit 302 receives the m-th sampling signal CSm and the m-th target value Vm to output the m-th processed sampling signal CSm_O, and finally automatically realizes that the average value of the m-th sampling signal CSm is equal to the m-th target value Vm through the switching circuit loop adjustment. Among them, the average value CS1′ of the first sampling signal is generated by the first averaging circuit 60 performing an averaging operation on the first sampling signal CS1. For example, refer to Figure 3, the first averaging circuit 60 includes an RC filter circuit, the RC filter circuit includes a first resistor R01 and a first capacitor C01 connected in series, the first end of the first resistor R01 receives the first sampling signal CS1, the second end of the first capacitor C01 receives the common mode voltage VCM, and the common end of the second end of the first resistor R01 and the first end of the first capacitor C01 is used as an output end to output the average value CS1' of the first sampling signal. Further, the m-th target value generating circuit 301 includes a programmable control circuit 3011 and a signal processing circuit 3012. The programmable control circuit 3011 can be programmed according to the heat dissipation conditions of the m-th phase switching circuit and the first phase switching circuit to set the control signal output by the programmable control circuit 3011; the signal processing circuit 3012 receives the average value CS1' of the first sampling signal and the control signal to output the m-th target value Vm. The m-th sampling signal processing circuit 302 includes an m-th averaging circuit 3021, a second operational amplifier U02 and a subtractor U03. The m-th averaging circuit 3021 receives the m-th sampling signal CSm, and performs an averaging operation to output the average value CSm′ of the m-th sampling signal; the second operational amplifier U02 receives the m-th target value Vm at the first input terminal, receives the average value CSm′ of the m-th sampling signal at the second input terminal, and outputs the error amplified signal at the output terminal; the subtractor U03 receives the m-th sampling signal CSm at the first input terminal, receives the error amplified signal at the second input terminal, and performs a subtraction operation on the m-th sampling signal CSm and the error amplified signal to output the m-th processed sampling signal CSm_O. By way of example, the m-th averaging circuit 3021 includes an RC filter circuit, the RC filter circuit includes a second resistor R02 and a second capacitor C02 connected in series, the first terminal of the second resistor R02 receives the m-th sampling signal CSm, the second terminal of the second capacitor C02 receives the common mode voltage VCM, and the common terminal of the second terminal of the second resistor R02 and the first terminal of the second capacitor C02 is used as the output terminal to output the average value CSm′ of the m-th sampling signal.

[0072] If the heat dissipation condition of the m-th phase switch circuit is better than that of the 1st phase switch circuit, the programmable control circuit 3011 can be programmed to set the control signal output by the programmable control circuit 3011 to adjust the m-th target value Vm output by the signal processing circuit 3012 to be greater than the average value CS1′ of the 1st sampling signal; if the heat dissipation condition of the m-th phase switch circuit is worse than that of the 1st phase switch circuit, the programmable control circuit 3011 can be programmed to set the control signal output by the programmable control circuit 3011 to adjust the m-th target value Vm to be less than the average value CS1′ of the 1st sampling signal. According to the "virtual short" characteristic of the second operational amplifier U02 in the m-th sampling signal processing circuit 302, it can be known that the average value CSm′ of the m-th sampling signal after the switch circuit loop adjustment will be equal to the m-th target value Vm. Thus, it can be achieved that if the heat dissipation condition of the m-phase switching circuit is better than that of the 1st-phase switching circuit, the average value of the m-th sampling signal Csm is greater than the average value of the 1st sampling signal Cs1; if the heat dissipation condition of the m-phase switching circuit is worse than that of the 1st-phase switching circuit, the average value of the m-th sampling signal Csm is less than the average value of the 1st sampling signal Cs1.

[0073] refer to Figure 4a and Figure 5a In one embodiment, the signal processing circuit 3012 includes a first operational amplifier U01 and a resistor array module 30121. The first input terminal of the first operational amplifier U01 receives the average value CS1′ of the first sampling signal; the resistor array module 30121 is connected to the second input terminal of the first operational amplifier U01 and the output terminal of the first operational amplifier U01, and the output terminal of the resistor array module 30121 outputs the mth target value Vm. The control signal output by the programmable control circuit 3011 is used to control the connection scheme between the resistor array module 30121, the second input terminal of the first operational amplifier U01, the output terminal of the first operational amplifier U01 and the output terminal of the resistor array module 30121. By way of example, the resistor array module 30121 includes a first resistor array 301211 and a second resistor array 301212.

[0074] like Figure 4aAs shown, if the heat dissipation condition of the m-th phase switch circuit is better than that of the 1st phase switch circuit, the control signal output by the programmable control circuit 3011 can be set by programming the programmable control circuit 3011, and the control signal can control the first end of the first resistor array 301211 and the output end of the first operational amplifier U01 to be connected to the first node, the second end of the first resistor array 301211, the first end of the second resistor array 301212 and the second input end of the first operational amplifier U01 to be connected to the second node, the second end of the second resistor array 301212 receives the common mode voltage VCM, and the first node outputs the m-th target value Vm as the output end of the resistor array module 30121. For example, the equivalent resistance of the second resistor array 301212 can be set to be equal to R, and the equivalent resistance of the first resistor array 301211 can be set to be equal to k1·R, where k1>0, and the m-th target value V can be obtained at this time. m =(1+k1)·CS1′, the m-th target value Vm is achieved to be greater than the average value CS1′ of the first sampling signal CS1, so that the average value of the m-th sampling signal Csm can be achieved to be greater than the average value of the first sampling signal CS1.

[0075] Figure 4b Based on Figure 4a The first upper limit voltage Vc1, the first sampling signal CS1, the mth processed sampling signal CSm_O, the mth sampling signal CSm, the first phase switch circuit inductor current i L1 and the inductor current i of the m-phase switching circuit Lm The first upper limit voltage Vc1 controls the peak values ​​of the first sampling signal CS1 and the mth processed sampling signal CSm_O, the average value of the mth processed sampling signal CSm_O is equal to the average value of the first sampling signal CS1, the average value of the mth sampling signal Csm is greater than the average value of the first sampling signal Cs1, and accordingly, the inductor current i of the mth phase switch circuit is Lm Greater than the inductor current i of the first phase switch circuit L1 If the heat dissipation condition of the m-phase switching circuit is better than that of the 1st-phase switching circuit, you can set Figure 4a The larger the equivalent resistance k1·R of the first resistor array 301211 is, the greater the average value of the mth sampling signal Csm is greater than the average value of the first sampling signal Cs1, thereby making the inductor current i of the mth phase switch circuit Lm With respect to the first phase switch circuit inductor current i L1 The greater the increase.

[0076] like Figure 5aAs shown, if the heat dissipation condition of the m-th phase switch circuit is worse than that of the 1st phase switch circuit, the control signal output by the programmable control circuit 3011 can be set by programming the programmable control circuit 3011, and the control signal can control the first end of the first resistor array 301211, the second input end of the first operational amplifier U01 and the output end of the first operational amplifier U01 to be connected to the third node, the second end of the first resistor array 301211 and the first end of the second resistor array 301212 to be connected to the fourth node, the second end of the second resistor array 301212 receives the common mode voltage VCM, and the fourth node outputs the m-th target value Vm as the output end of the resistor array module 30121. For example, the equivalent resistance of the first resistor array 301211 can be set to be equal to (1-k2)·R, and the equivalent resistance of the second resistor array 301212 can be set to be equal to k2·R, where 0<k2<1, and the m-th target value V can be obtained at this time. m =k2·CS1′, the m-th target value Vm is smaller than the average value CS1′ of the first sampling signal CS1, so that the average value of the m-th sampling signal Csm is smaller than the average value of the first sampling signal Cs1.

[0077] Figure 5b Based on Figure 5a The first upper limit voltage Vc1, the first sampling signal CS1, the mth processed sampling signal CSm_O, the mth sampling signal CSm, the first phase switch circuit inductor current i L1 and the inductor current i of the m-phase switching circuit Lm Schematic diagram of waveform. The first upper limit voltage Vc1 controls the peak values ​​of the first sampling signal CS1 and the mth processed sampling signal CSm_O, the average value of the mth processed sampling signal CSm_O is equal to the average value of the first sampling signal CS1, and the average value of the mth sampling signal Csm is less than the average value of the first sampling signal Cs1. Accordingly, the inductor current i of the mth phase switch circuit is Lm Less than the inductor current i of the first phase switch circuit L1 If the heat dissipation condition of the m-phase switching circuit is worse than that of the 1st-phase switching circuit, you can set Figure 5a The smaller the equivalent resistance (1-k2)·R of the first resistor array 301211 and the equivalent resistance k2·R of the second resistor array 301212, the greater the degree to which the average value of the mth sampling signal Csm is less than the average value of the first sampling signal Cs1, thereby making the inductor current i of the mth phase switch circuit Lm With respect to the first phase switch circuit inductor current i L1 The greater the reduction.

[0078] In the first embodiment, the average value of the m-th sampling signal can be adjusted relative to the average value of the 1st sampling signal according to the heat dissipation conditions of the m-th phase switching circuit and the 1st phase switching circuit, thereby adjusting the current size of the inductor current of the m-th phase switching circuit relative to the inductor current of the 1st phase switching circuit, ultimately making the current of the switching circuit at a position with good heat dissipation conditions in the multi-phase switching circuit larger, and the current of the switching circuit at a position with good heat dissipation conditions smaller, thereby achieving temperature balance.

[0079] like Figure 6 As shown, the multi-phase switching circuit of the second embodiment of the present invention includes: an n-phase switching circuit 10, an inductor current sampling circuit 20, an n-1-phase thermal balance adjustment circuit 30', a first switching signal generating circuit 40', an m-th switching signal generating circuit 41' and a first upper limit voltage generating circuit 50, wherein n is an integer greater than 1, and m is an integer from 2 to n. Among them, the n-phase switching circuit 10, the inductor current sampling circuit 20 and the first upper limit voltage generating circuit 50 in this embodiment are the same as the corresponding circuits in the first embodiment, and are not repeated here. In this embodiment, the m-th phase thermal balance adjustment circuit 30' receives the first upper limit voltage Vc1, and can adjust the output m-th upper limit voltage Vcm according to the heat dissipation condition of the m-th phase switching circuit and the heat dissipation condition of the first phase switching circuit. The first switching signal generating circuit 40' receives a first upper limit voltage Vc1 representing the inductor current i of the first phase switching circuit. L1 The first sampling signal CS1 and the first upper limit voltage Vc1 are used to output the first phase switching signal PWM1; the mth switching signal generating circuit 41 ′ receives the inductor current i representing the mth phase switching circuit. Lm The mth sampling signal CSm and the mth upper limit voltage Vcm are used to output the mth phase switching signal PWMm; wherein the first upper limit voltage Vc1 controls the peak value of the first sampling signal CS1 to control the inductor current i of the first phase switching circuit. L1 The m-th upper limit voltage Vcm controls the peak value of the m-th sampling signal CSm to control the inductor current i of the m-th phase switch circuit. Lm The first phase switching signal PWM1 is used to control the on and off of the main switch tube of the first phase switching circuit; the m-th phase switching signal PWMm is used to control the on and off of the main switch tube of the m-th phase switching circuit.

[0080] In this embodiment, if the heat dissipation condition of the m-phase switch circuit is better than that of the first-phase switch circuit, the m-phase thermal balance adjustment circuit 30' can set the m-th upper limit voltage Vcm to be greater than the first upper limit voltage Vc1; if the heat dissipation condition of the m-phase switch circuit is worse than that of the first-phase switch circuit, the m-phase thermal balance adjustment circuit 30' can set the m-th upper limit voltage Vcm to be less than the first upper limit voltage Vc1. Thus, if the heat dissipation condition of the m-phase switch circuit is better than that of the first-phase switch circuit, the inductor current of the m-phase switch circuit can be adjusted to increase relative to the inductor current of the first-phase switch circuit; if the heat dissipation condition of the m-phase switch circuit is worse than that of the first-phase switch circuit, the inductor current of the m-phase switch circuit can be adjusted to decrease relative to the inductor current of the first-phase switch circuit. It can be understood that in this embodiment, the multi-phase switch circuit includes an n-1-phase thermal balance adjustment circuit 30', and in other embodiments, it can also include a k-phase thermal balance adjustment circuit 30', where k is an integer from 1 to (n-1).

[0081] In one embodiment, Figure 7 As shown, the m-th phase thermal balance regulating circuit 30' comprises a programmable control circuit 3011' and a signal processing circuit 3012'. The programmable control circuit 3011' can be programmed according to the heat dissipation conditions of the m-th phase switch circuit and the first phase switch circuit to set the control signal output by the programmable control circuit 3011'; the signal processing circuit 3012' receives the first upper limit voltage Vc1 and the control signal to output the m-th upper limit voltage Vcm.

[0082] If the heat dissipation condition of the m-th phase switch circuit is better than that of the 1st phase switch circuit, the programmable control circuit 3011′ can be programmed to set the control signal output by the programmable control circuit 3011′ to adjust the m-th upper limit voltage Vcm to be greater than the first upper limit voltage Vc1; if the heat dissipation condition of the m-th phase switch circuit is worse than that of the 1st phase switch circuit, the programmable control circuit 3011′ can be programmed to set the control signal output by the programmable control circuit 3011′ to adjust the m-th upper limit voltage Vcm to be less than the first upper limit voltage Vc1.

[0083] refer to Figure 8a and Figure 9aIn one embodiment, the signal processing circuit 3012′ includes a first operational amplifier U01′ and a resistor array module 30121′. The first input terminal of the first operational amplifier U01 receives the first upper limit voltage Vc1; the resistor array module 30121′ is connected to the second input terminal of the first operational amplifier U01′ and the output terminal of the first operational amplifier U01′, and the output terminal of the resistor array module outputs the mth upper limit voltage Vcm. The control signal output by the programmable control circuit 3011′ controls the connection scheme between the resistor array module 30121′, the second input terminal of the first operational amplifier U01′, the output terminal of the first operational amplifier U01, and the output terminal of the resistor array module 30121′. By way of example, the resistor array module 30121′ includes a first resistor array 301211′ and a second resistor array 301212′.

[0084] like Figure 8a As shown, if the m-th phase switch circuit has better heat dissipation condition than the 1st phase switch circuit, the programmable control circuit 3011′ can be programmed to set the control signal output by the programmable control circuit 3011′, and the control signal can control the connection scheme and the connection scheme between the first resistor array 301211′ and the second resistor array 301212′, the second input end of the first operational amplifier U01′, the output end of the first operational amplifier U01′ and the output end of the resistor array module 30121′. Figure 4a The connection scheme shown is the same, except that, in this embodiment, the first input terminal of the first operational amplifier U01 receives the first upper limit voltage Vc1, and the output terminal of the resistor array module 30121′ outputs the mth upper limit voltage Vcm. Similarly, the equivalent resistance of the second resistor array 301212′ can be set to be equal to R, and the equivalent resistance of the first resistor array 301211′ can be set to be equal to k1·R, where k1>0, and in this case, the mth upper limit voltage Vcm=(1+k1)·Vc1, which realizes that the mth upper limit voltage Vcm is greater than the first upper limit voltage Vc1.

[0085] Figure 8b Based on Figure 8a The first upper limit voltage Vc1, the mth upper limit voltage Vcm, the first sampling signal CS1, the mth sampling signal CSm, the first phase switch circuit inductor current i L1 and the inductor current i of the m-phase switching circuit Lm The first upper limit voltage Vc1 controls the peak value of the first sampling signal CS1 to control the inductor current i of the first phase switch circuit. L1 The mth upper limit voltage Vcm controls the peak value of the mth sampling signal CSm to control the inductor current i of the mth phase switch circuit. LmThe peak value of the m-th upper limit voltage Vcm is greater than the first upper limit voltage Vc1. Accordingly, the inductor current i of the m-th phase switch circuit is Lm Greater than the inductor current i of the first phase switch circuit L1 If the heat dissipation condition of the m-phase switching circuit is better than that of the 1st-phase switching circuit, you can set Figure 8a The larger the k1 in the m-th upper limit voltage Vcm is, the greater the degree to which it is greater than the first upper limit voltage Vc1 is, and thus the inductor current i of the m-th phase switch circuit is Lm With respect to the first phase switch circuit inductor current i L1 The greater the increase.

[0086] like Figure 9a As shown, if the heat dissipation condition of the m-th phase switch circuit is worse than that of the 1st phase switch circuit, the control signal output by the programmable control circuit 3011′ can be set by programming the programmable control circuit 3011′, and the control signal can control the connection scheme and the connection scheme between the first resistor array 301211′ and the second resistor array 301212′, the second input end of the first operational amplifier U01′, the output end of the first operational amplifier U01′ and the output end of the resistor array module 30121′. Figure 5a The connection scheme shown is the same, except that, in this embodiment, the first input terminal of the first operational amplifier U01 receives the first upper limit voltage Vc1, and the output terminal of the resistor array module 30121′ outputs the mth upper limit voltage Vcm. Similarly, the equivalent resistance of the first resistor array 301211′ can be set to be equal to (1-k2)·R, and the equivalent resistance of the second resistor array 301212′ can be set to be equal to k2·R, where 0<k2<1, and the mth upper limit voltage Vcm=k2·Vc1 can be obtained at this time, so that the mth upper limit voltage Vcm is less than the first upper limit voltage Vc1.

[0087] Figure 9b Based on Figure 9a The first upper limit voltage Vc1, the mth upper limit voltage Vcm, the first sampling signal CS1, the mth sampling signal CSm, the first phase switch circuit inductor current i L1 and the inductor current i of the m-phase switching circuit Lm The first upper limit voltage Vc1 controls the peak value of the first sampling signal CS1 to control the inductor current i of the first phase switch circuit. L1 The mth upper limit voltage Vcm controls the peak value of the mth sampling signal CSm to control the inductor current i of the mth phase switch circuit. Lm The peak value of the m-th upper limit voltage Vcm is less than the first upper limit voltage Vc1. Accordingly, the inductor current i of the m-th phase switch circuit is Lm Less than the inductor current i of the first phase switch circuit L1If the heat dissipation condition of the m-phase switching circuit is worse than that of the 1st-phase switching circuit, you can set Figure 9a The smaller the k2 in the m-th upper limit voltage Vcm is, the greater the degree to which it is lower than the first upper limit voltage Vc1 is, and thus the inductor current i of the m-th phase switch circuit is Lm With respect to the first phase switch circuit inductor current i L1 The greater the reduction.

[0088] In the second embodiment, the magnitude of the mth upper limit voltage relative to the first upper limit voltage can be adjusted according to the heat dissipation conditions of the mth phase switching circuit and the first phase switching circuit, thereby adjusting the magnitude of the inductor current of the mth phase switching circuit relative to the inductor current of the first phase switching circuit, ultimately increasing the current of the switching circuit at a position with good heat dissipation conditions in the multi-phase switching circuit, and decreasing the current of the switching circuit at a position with good heat dissipation conditions, thereby achieving temperature balance.

[0089] The above-described implementation methods do not constitute a limitation on the protection scope of the technical solution. Any modification, equivalent replacement and improvement made within the spirit and principle of the above-described implementation methods shall be included in the protection scope of the technical solution.

Claims

1. A multi-phase switching circuit, comprising an n-phase switching circuit, characterized in that: The multi-phase switching circuit includes a k-phase thermal balance regulating circuit, wherein: The m-phase thermal balance adjustment circuit adjusts the inductor current of the m-phase switch circuit according to the heat dissipation condition of the m-phase switch circuit and the heat dissipation condition of the first-phase switch circuit. so that the inductor current of the m-th phase switch circuit matches the heat dissipation condition of the m-th phase switch circuit; Herein, n is an integer greater than 1, k is an integer from 1 to (n-1), and m is an integer from 2 to n.

2. The multi-phase switching circuit according to claim 1, characterized in that: If the heat dissipation condition of the m-phase switch circuit is better than that of the first-phase switch circuit, the m-phase heat balance adjustment circuit may adjust the inductance current of the m-phase switch circuit to increase relative to the inductance current of the first-phase switch circuit; If the heat dissipation condition of the m-phase switching circuit is worse than that of the 1st-phase switching circuit, the m-phase thermal balance adjustment circuit can adjust the inductance current of the m-phase switching circuit to be smaller than the inductance current of the 1st-phase switching circuit.

3. The multi-phase switching circuit according to claim 2, characterized in that: If the heat dissipation condition of the m-th phase switch circuit is better than that of the 1st phase switch circuit, the m-th phase heat balance adjustment circuit may adjust the average value of the m-th sampling signal to be greater than the average value of the 1st sampling signal; If the heat dissipation condition of the m-th phase switch circuit is worse than that of the first phase switch circuit, the m-th phase heat balance adjustment circuit may adjust the average value of the m-th sampling signal to be smaller than the average value of the first sampling signal; The first sampling signal represents the inductor current of the first phase switch circuit, and the mth sampling signal represents the inductor current of the mth phase switch circuit.

4. The multi-phase switching circuit according to claim 3, characterized in that: The m-th phase thermal balance regulating circuit comprises: an m-th target value generating circuit, receiving the average value of the first sampling signal to output the m-th target value, and adjusting the m-th target value according to the heat dissipation conditions of the m-th phase switching circuit and the first phase switching circuit; if the heat dissipation condition of the m-th phase switching circuit is better than that of the first phase switching circuit, the m-th target value can be adjusted to be greater than the average value of the first sampling signal; if the heat dissipation condition of the m-th phase switching circuit is worse than that of the first phase switching circuit, the m-th target value can be adjusted to be less than the average value of the first sampling signal; The mth sampling signal processing circuit receives the mth sampling signal and the mth target value to output an mth processed sampling signal.

5. The multi-phase switching circuit according to claim 4, characterized in that: The mth target value generating circuit comprises: A programmable control circuit, which can be programmed according to the heat dissipation conditions of the m-phase switch circuit and the first-phase switch circuit to set the control signal output by the programmable control circuit; The signal processing circuit receives the average value of the first sampling signal and the control signal to output the mth target value.

6. The multi-phase switching circuit according to claim 5, characterized in that: The signal processing circuit includes a first operational amplifier and a resistor array module. The first input terminal of the first operational amplifier receives the average value of the first sampling signal; the resistor array module is connected to the second input terminal of the first operational amplifier and the output terminal of the first operational amplifier, and the output terminal of the resistor array module outputs the mth target value; The control signal controls a connection scheme among the resistor array module, the second input terminal of the first operational amplifier, the output terminal of the first operational amplifier, and the output terminal of the resistor array module.

7. The multi-phase switching circuit according to claim 4, characterized in that: The mth sampling signal processing circuit comprises: an m-th averaging circuit, receiving the m-th sampling signal, and performing an averaging operation to output an average value of the m-th sampling signal; A second operational amplifier, having a first input terminal receiving the mth target value, a second input terminal receiving the average value of the mth sampling signal, and an output terminal outputting an error amplified signal; A subtractor, having a first input terminal receiving the mth sampling signal and a second input terminal receiving the error amplified signal, performs a subtraction operation on the mth sampling signal and the error amplified signal to output the mth processed sampling signal.

8. The multi-phase switching circuit according to claim 4, characterized in that: The multi-phase switching circuit further includes a first switching signal generating circuit and an mth switching signal generating circuit. The first switch signal generating circuit receives the first sampling signal and the first upper limit voltage to output the first phase switch signal; the mth switch signal generating circuit receives the mth processed sampling signal and the first upper limit voltage to output the mth phase switch signal; The first upper limit voltage controls the peak values ​​of the first sampling signal and the mth processed sampling signal; The first phase switch signal is used to control the on and off of the main switch tube of the first phase switch circuit; the mth phase switch signal is used to control the on and off of the main switch tube of the mth phase switch circuit.

9. The multi-phase switching circuit according to claim 2, characterized in that: If the heat dissipation condition of the m-th phase switch circuit is better than that of the 1st phase switch circuit, the m-th phase heat balance adjustment circuit may set the m-th upper limit voltage to be greater than the first upper limit voltage; If the heat dissipation condition of the m-th phase switch circuit is worse than that of the 1st phase switch circuit, the m-th phase thermal balance adjustment circuit may set the m-th upper limit voltage to be less than the first upper limit voltage.

10. The multi-phase switching circuit according to claim 9, characterized in that: The multi-phase switching circuit further includes a first switching signal generating circuit and an mth switching signal generating circuit. The first switch signal generating circuit receives a first sampling signal representing the inductor current of the first phase switch circuit and the first upper limit voltage to output a first phase switch signal; The mth switching signal generating circuit receives the mth sampling signal representing the inductor current of the mth phase switching circuit and the mth upper limit voltage to output the mth phase switching signal; The first upper limit voltage controls the peak value of the first sampling signal, and the mth upper limit voltage controls the peak value of the mth sampling signal; The first phase switch signal is used to control the on and off of the main switch tube of the first phase switch circuit; The m-th phase switch signal is used to control the on and off of the main switch tube of the m-th phase switch circuit.

11. A method for regulating thermal balance of a multi-phase switching circuit, wherein the multi-phase switching circuit comprises an n-phase switching circuit, characterized in that: include: If the heat dissipation condition of the m-phase switch circuit is better than that of the first-phase switch circuit, the inductor current of the m-phase switch circuit may be adjusted to increase relative to the inductor current of the first-phase switch circuit; If the heat dissipation condition of the m-phase switch circuit is worse than that of the first-phase switch circuit, the inductor current of the m-phase switch circuit may be adjusted to be smaller than the inductor current of the first-phase switch circuit; Herein, n is an integer greater than 1, and m is an integer from 2 to n.

12. The heat balance adjustment method according to claim 11, characterized in that: The heat balance adjustment method further comprises: If the heat dissipation condition of the m-th phase switch circuit is better than that of the 1st phase switch circuit, the average value of the m-th sampling signal can be adjusted to be greater than the average value of the 1st sampling signal; If the heat dissipation condition of the m-th phase switch circuit is worse than that of the 1st phase switch circuit, the average value of the m-th sampling signal may be adjusted to be smaller than the average value of the 1st sampling signal; The first sampling signal represents the inductor current of the first phase switch circuit, and the mth sampling signal represents the inductor current of the mth phase switch circuit.

13. The heat balance adjustment method according to claim 12, characterized in that: The method for adjusting the average value of the mth sampling signal further comprises: If the heat dissipation condition of the m-th phase switch circuit is better than that of the 1st phase switch circuit, the m-th target value may be set to be greater than the average value of the 1st sampling signal; if the heat dissipation condition of the m-th phase switch circuit is worse than that of the 1st phase switch circuit, the m-th target value may be set to be less than the average value of the 1st sampling signal; and making the average value of the mth sampling signal equal to the mth target value; And obtain the mth processed sampling signal according to the mth sampling signal and the mth target value.

14. The heat balance adjustment method according to claim 13, characterized in that: Also includes: Obtaining a first phase switch signal according to the first sampling signal and a first upper limit voltage; Obtaining an m-th phase switching signal according to the m-th processed sampling signal and the first upper limit voltage; The first upper limit voltage controls the peak values ​​of the first sampling signal and the mth processed sampling signal; The first phase switch signal is used to control the on and off of the main switch tube of the first phase switch circuit; The m-th phase switch signal is used to control the on and off of the main switch tube of the m-th phase switch circuit.

15. The heat balance regulating method according to claim 11, characterized in that: The heat balance adjustment method further comprises: If the heat dissipation condition of the m-th phase switch circuit is better than that of the first phase switch circuit, the m-th upper limit voltage may be set to be greater than the first upper limit voltage; if the heat dissipation condition of the m-th phase switch circuit is worse than that of the first phase switch circuit, the m-th upper limit voltage may be set to be less than the first upper limit voltage; The first upper limit voltage is used to control the peak value of the inductor current of the first phase switching circuit; the mth upper limit voltage is used to control the peak value of the inductor current of the mth phase switching circuit.

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