Direct current conversion circuit, control method thereof, electronic equipment and server

Abstract

The invention discloses a direct current conversion circuit, a control method thereof, electronic equipment and a server, and relates to the technical field of electronic circuits. The switch topology module is used for converting an input voltage into a target voltage according to a driving signal received by a driving receiving port of the switch topology module; the switch topology module comprises a transformer, the primary side of the transformer is used as an output filter inductor of the switch topology module, and when the transformer is coupled with the inductive coupling module, the equivalent inductance of the output filter inductor is reduced so as to improve the current dynamic response of the DC conversion circuit; the inductive coupling module is connected with the secondary side of the transformer, receives a coupling control signal through a coupling control port of the inductive coupling module, controls the inductive coupling module to be coupled with the transformer, reduces equivalent inductance of an output filter inductor, improves current dynamic response of the direct-current conversion circuit, and enables the direct-current conversion circuit to be in a stable state after the direct-current conversion circuit reaches the stable state. The compensation inductor is decoupled from the primary side of the transformer so as to reduce ripples of the output end and improve the conversion efficiency of the direct current conversion circuit.

Description

Technical Field

[0001] The present application relates to the field of electronic circuit technology, and in particular to a direct current conversion circuit and a control method thereof, an electronic device and a server. Background Art

[0002] The switching power supply is a voltage conversion circuit widely used in electronic products. The energy storage element is used to adjust the circuit working state when the load changes, so that the circuit returns to a steady state. When the load current suddenly changes and the circuit enters a transient state, the inductor current must be adjusted to the new load current in time. After a period of adjustment, there will be a certain gap between the load current and the inductor current. At this time, the capacitor is charged and discharged for adjustment. The shorter the transient adjustment time, the better the dynamic response capability of the circuit.

[0003] Under the same voltage excitation, a small inductance value can make the current change rate faster and the transient adjustment time of the load current shorter. Therefore, the dynamic response capability of the circuit is usually improved by reducing the output filter inductance. However, a small inductance will cause the peak-to-peak value of the inductor current to increase, which is easy to cause inductor saturation and reduce the power conversion efficiency. Due to the above contradiction, in actual situations, the dynamic response capability of the switching power supply cannot be improved by simply reducing the inductance. Summary of the invention

[0004] In order to solve the contradiction between the dynamic response capability of the switching power supply and the inductor saturation and the reduction of power conversion efficiency, the present application provides the following technical solutions: In a first aspect, a direct current conversion circuit is provided, comprising: A switch topology module, used for converting an input voltage into a target voltage according to a driving signal received by a driving receiving port thereof; The switch topology module includes a transformer, the primary side of the transformer serves as an output filter inductor of the switch topology module, and when the transformer is coupled with the inductor coupling module, the equivalent inductance of the output filter inductor is reduced to improve the current dynamic response of the DC conversion circuit; The inductive coupling module is connected to the secondary side of the transformer, receives a coupling control signal through its coupling control port, and controls the coupling between the inductive coupling module and the transformer to reduce the equivalent inductance of the output filter inductor and improve the current dynamic response of the DC conversion circuit.

[0005] Further, the switch topology module also has: a switch topology module first coupling port and a switch topology module second coupling port; The inductive coupling module also has: a first coupling port of the inductive coupling module and a second coupling port of the inductive coupling module; The first coupling port of the switch topology module is connected to the first coupling port of the inductive coupling module, and the second coupling port of the switch topology module is connected to the second coupling port of the inductive coupling module.

[0006] Further, the switch topology module also includes a switch unit; The switch unit has a drive input port, a voltage input port and a switch unit output port; The driving input port serves as the driving receiving port, the switching unit output port is connected to the same-name end of the primary side of the transformer, the same-name end of the secondary side of the transformer serves as the first coupling port of the switching topology module, and the other end of the secondary side of the transformer serves as the second coupling port of the switching topology module.

[0007] Furthermore, the inductive coupling module includes: a coupled inductor and a switch; The switch has: a first switch port, a second switch port and a third switch port; The first port of the switch is used as a coupling control port, the second port of the switch is used as a first coupling port of the inductive coupling module, the third port of the switch is connected to one end of the coupling inductor and then grounded, and the other end of the coupling inductor is used as a second coupling port of the inductive coupling module.

[0008] Furthermore, the DC conversion circuit further includes: A current sampling module, used for collecting the current flowing through the secondary side of the transformer from the inductive coupling module; A signal amplification module, used to amplify the collected current flowing through the secondary side of the transformer; The signal processing module is used to transmit a control signal to the coupling control port according to the amplified current signal on the secondary side of the transformer, and to adjust the drive signal according to the output voltage.

[0009] Furthermore, the inductive coupling module also has: a first detection port and a second detection port; The current sampling module has: a first sampling port, a second sampling port and a third sampling port; The signal amplification module has: a first port of the signal amplification module, a second port of the signal amplification module and a third port of the signal amplification module; The signal processing module has: a first feedback port, a second feedback port, a first output port and a second output port; The first detection port is connected to the first sampling port, the second detection port is connected to the second sampling port, the third sampling port is connected to the first port of the signal amplification module, the second port of the signal amplification module is connected to the second detection port of the inductive coupling module, the third port of the signal amplification module is connected to the second feedback port, the first feedback port is connected to the voltage output port of the switch topology module, the first output port is connected to the coupling control port, and the second output port is connected to the drive receiving port.

[0010] Further, the current sampling module includes: a first resistor and a first capacitor; One end of the first resistor serves as a first sampling port, the other end of the first resistor is connected to one end of the first capacitor and serves as a third sampling port, and the other end of the first capacitor serves as a second sampling port.

[0011] Further, the signal amplification module includes: an operational amplifier, a second resistor, a third resistor, a fourth resistor and a fifth resistor; One end of the second resistor is connected to one end of the fourth resistor and then connected to the in-phase input terminal of the operational amplifier, the other end of the second resistor serves as the first port of the signal amplification module, one end of the third resistor is connected to one end of the fifth resistor and then connected to the inverting input terminal of the operational amplifier, the other end of the third resistor serves as the second port of the signal amplification module, and the other end of the fifth resistor is connected to the output terminal of the operational amplifier and then serves as the third port of the signal amplification module.

[0012] Furthermore, the signal processing module includes: The analog-to-digital conversion unit is used to determine the coupling control signal according to the output terminal signal of the operational amplifier, and determine the pulse signal according to the output voltage, so that the driving unit can determine the driving signal; The driving unit is used to determine the driving signal according to the pulse signal determined by the analog-to-digital conversion unit.

[0013] Further, the analog-to-digital conversion unit has: a first receiving port, a second receiving port, a first transmitting port and a second transmitting port; The driving unit has: a pulse receiving port and a driving transmission port; The first receiving port serves as a first feedback port, the second receiving port serves as a second feedback port, the first transmission port serves as a first output port, the second transmission port is connected to the pulse receiving port, and the driving transmission port serves as a second output port.

[0014] Further, the switch unit includes a first transistor and a diode; The first transistor comprises: a first transistor first electrode, a first transistor second electrode and a first transistor third electrode; The first electrode of the first transistor is used as a driving input port, the second electrode of the first transistor is connected to the input voltage, the third electrode of the first transistor is connected to the cathode of the diode, and the anode of the diode is grounded.

[0015] Further, the driver receiving port has a first receiving sub-port and a second receiving sub-port; The switch unit includes a second transistor and a third transistor; The second transistor comprises: a second transistor first electrode, a second transistor second electrode and a second transistor third electrode; The third transistor comprises: a third transistor first electrode, a third transistor second electrode and a third transistor third electrode; The first electrode of the second transistor serves as a first receiving sub-port, the third electrode of the second transistor is connected to the second electrode of the third transistor, and the first electrode of the third transistor serves as a second receiving sub-port.

[0016] Further, the second transistor and the third transistor are both N-MOSFETs; The high level phases of the driving signals received by the first receiving sub-port and the second receiving sub-port are complementary.

[0017] Further, the second transistor is a P-MOSFET, and the third transistor is an N-MOSFET; The high level phases of the driving signals received by the first receiving sub-port and the second receiving sub-port are the same.

[0018] Further, the second output port includes a first driver output sub-port and a second driver output sub-port; The first driving output sub-port is connected to the first receiving sub-port and is used to provide a driving signal to the second transistor; And the second driving output sub-port is connected to the second receiving sub-port for providing a driving signal to the third transistor.

[0019] In a second aspect, an electronic device is provided, comprising the DC conversion circuit described in the first aspect.

[0020] In a third aspect, a server is provided, comprising the DC conversion circuit described in the first aspect.

[0021] In a fourth aspect, a DC conversion circuit control method is provided, which is applied to the DC conversion circuit described in the first aspect, comprising: In response to the absolute value of the difference between the output voltage and the preset voltage value exceeding the first threshold value, and the output voltage change rate exceeding the second threshold value, the drive signal is adjusted to restore the output voltage to the preset voltage value, and the coupling signal is used as the coupling control signal and transmitted to the coupling control port to couple the inductive coupling module with the transformer to reduce the equivalent inductance of the output filter inductor in the DC conversion circuit and improve the response speed of the DC conversion circuit.

[0022] Furthermore, the DC conversion circuit control method further includes: In response to the output voltage change rate not exceeding the second threshold value, and the absolute value of the difference between the output voltage and the preset voltage value exceeding the first threshold value, the driving signal is adjusted to restore the output voltage to the preset voltage value.

[0023] Furthermore, the DC conversion circuit control method further includes: In response to the DC current component of the compensation inductor dropping to 0, it is transmitted to the coupling control port, and the decoupling signal is used as the coupling control signal and transmitted to the coupling control port, so that the inductive coupling module is decoupled from the transformer, and the primary side of the transformer is used as the output filter inductor to reduce the output ripple.

[0024] The technical solution provided in the embodiment of the present application has the following beneficial effects: by using the primary side of the transformer as the output filter inductor and adopting a switch on the secondary side of the transformer to control the compensation inductor to couple with the primary side of the transformer, the equivalent inductance of the output filter inductor can be reduced when the compensation inductor is coupled with the primary side of the transformer, thereby improving the dynamic response capability of the DC conversion circuit; and after the DC conversion circuit reaches a steady state, the compensation inductor is decoupled from the primary side of the transformer, and a larger output filter inductor is adopted to reduce the ripple at the output end and improve the conversion efficiency of the DC conversion circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0026] Figure 1 This is a schematic diagram of a DC conversion circuit module provided in an embodiment of the present application; Figure 2 is another schematic diagram of a DC conversion circuit module provided in an embodiment of the present application; Figure 3 is a schematic diagram of an inductive coupling module circuit provided in an embodiment of the present application; Figure 4 is a circuit diagram of a current sampling module provided in an embodiment of the present application; Figure 5 is a circuit diagram of a signal amplification module provided in an embodiment of the present application; Figure 6 is a schematic diagram of a signal processing module provided in an embodiment of the present application; Figure 7 is a schematic diagram of a switch unit circuit provided in an embodiment of the present application; Figure 8 This is another schematic diagram of connecting a signal processing module and a switch topology module provided in an embodiment of the present application; Fig. 9 is another schematic diagram of a switch unit circuit provided in an embodiment of the present application; Fig.10 is another schematic diagram of a switch unit circuit provided in an embodiment of the present application; Fig.111 is a timing diagram of the compensation inductor current provided in an embodiment of the present application. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solutions and advantages of this application clearer, the technical solutions in the implementation mode of this application will be clearly and completely described below in conjunction with the drawings in the implementation mode of this application. Obviously, the described implementation mode is only a part of the embodiments of this application, not all embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0028] Unless otherwise defined, the technical terms or scientific terms used in the present disclosure shall have the usual meanings understood by persons with ordinary skills in the field to which the present disclosure belongs. The words "first", "second" and similar words used in the present disclosure do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, words such as "one", "one" or "the" do not indicate a quantity limitation, but indicate that there is at least one. The numbers in the drawings of the specification only indicate the distinction between various functional components or modules, and do not indicate the logical relationship between components or modules. Words such as "include" or "comprise" and similar words mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Words such as "connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0029] Hereinafter, various embodiments according to the present disclosure will be described in detail with reference to the accompanying drawings. It should be noted that in the accompanying drawings, the same reference numerals are given to components having substantially the same or similar structures and functions, and repeated descriptions thereof will be omitted.

[0030] In view of the contradiction that improving the dynamic response capability of the switching power supply by reducing the output filter inductance will bring about defects such as inductor saturation and reduced power conversion efficiency, the present application provides the following embodiments.

[0031] In some embodiments, Figure 1 As shown, a DC conversion circuit includes: The switch topology module 100 is used to drive the input voltage V according to the driving signal received by the driving receiving port 101. IN Convert to target voltage; The switch topology module 100 includes a transformer 120, the primary side of the transformer 120 serves as an output filter inductor of the switch topology module 100, and when the transformer 120 is coupled with the inductor coupling module 200, the equivalent inductance of the output filter inductor is reduced to improve the current dynamic response of the DC conversion circuit; The inductive coupling module 200 is connected to the secondary side of the transformer 120, receives a coupling control signal through its coupling control port 201, and controls the coupling between the inductive coupling module 200 and the transformer 120 to reduce the equivalent inductance of the output filter inductor and improve the current dynamic response of the DC conversion circuit.

[0032] It should be noted that the DC conversion circuit referred to in the present application is a switch circuit including an output filter inductor. For ease of explanation, a BUCK circuit is used as an example for explanation.

[0033] The switch topology module 100 further comprises: a switch topology module first coupling port 103 and a switch topology module second coupling port 104; The inductive coupling module 200 further comprises: an inductive coupling module first coupling port 202 and an inductive coupling module second coupling port 203; The first coupling port 103 of the switch topology module is connected to the first coupling port 202 of the inductive coupling module, and the second coupling port 104 of the switch topology module is connected to the second coupling port 203 of the inductive coupling module.

[0034] The voltage output port 102 of the switch topology module 100 is used to output a preset voltage.

[0035] Specifically, the switch topology module 100 further includes a switch unit 110; The switch unit 110 has a driving input port 111 , a voltage input port 112 , and a switch unit output port 113 ; The driving input port 111 serves as the driving receiving port 101, the switching unit output port 113 is connected to the same-name end of the primary side of the transformer 120, the same-name end of the secondary side of the transformer 120 serves as the first coupling port 103 of the switching topology module, and the other end of the secondary side of the transformer 120 serves as the second coupling port 104 of the switching topology module.

[0036] The other end of the primary side of the transformer 120 serves as a voltage output port 102 .

[0037] Preferably, if Figure 2 As shown, the other end of the primary side of the transformer 120 is connected in series with a second capacitor C 2 Then ground.

[0038] like Figure 3 As shown, the inductive coupling module 200 includes: a coupling inductor L c and a switch S; The switch S has: a first switch port S 1 , switch second port S 2 And the third port of the switch S 3 ; Switch first port S 1 As the coupling control port 201, the switch second port S 2 As the first coupling port 202 of the inductive coupling module, the third port S of the switch 3 With coupled inductor L c One end is connected to ground, and the coupling inductor L c The other end serves as the second coupling port 203 of the inductive coupling module.

[0039] The DC conversion circuit also includes: The current sampling module 300 is used to collect the current flowing through the secondary side of the transformer 120 from the inductive coupling module 200; The signal amplification module 400 is used to amplify the collected current flowing through the secondary side of the transformer 120; The signal processing module 500 is used to transmit a control signal to the coupling control port 201 according to the amplified current signal on the secondary side of the transformer 120 , and to adjust the driving signal according to the output voltage.

[0040] The inductive coupling module 200 further has: a first detection port 204 and a second detection port 205; The current sampling module 300 has: a first sampling port 301 , a second sampling port 302 and a third sampling port 303 ; The signal amplifying module 400 has: a first signal amplifying module port 401 , a second signal amplifying module port 402 , and a third signal amplifying module port 403 ; The signal processing module 500 has: a first feedback port 501 , a second feedback port 502 , a first output port 503 and a second output port 504 ; The first detection port 204 is connected to the first sampling port 301, the second detection port 205 is connected to the second sampling port 302, the third sampling port 303 is connected to the first port 401 of the signal amplification module, the second port 402 of the signal amplification module is connected to the second detection port 205 of the inductive coupling module, the third port 403 of the signal amplification module is connected to the second feedback port 502, the first feedback port 501 is connected to the voltage output port 102 of the switch topology module, the first output port 503 is connected to the coupling control port 201, and the second output port 504 is connected to the drive receiving port 101.

[0041] like Figure 4 As shown, the current sampling module 300 includes: a first resistor R 1And the first capacitor C 1 ; The first resistor R 1 One end of the first sampling port 301 is used as the first sampling port 301, and the first resistor R 1 The other end of the first capacitor C 1 One end of the first capacitor C is connected as the third sampling port 303. 1 The other end of the device serves as a second sampling port 302 .

[0042] After the first resistor and the second capacitor are connected in series, they are connected in parallel to the two ends of the compensation inductor, and current sampling is performed on the compensation inductor. The current sampling method is DCR (DC equivalent resistance) current sampling. Since the non-productive inductor can be equivalent to the series connection of an ideal inductor and a parasitic resistor, by adjusting the values ​​of the first capacitor and the first resistor, the voltage across the first capacitor can be equal to the voltage of the parasitic resistor, and the current value flowing through the compensation inductor is obtained by dividing the voltage value by the resistance value of the parasitic resistor.

[0043] like Figure 5 As shown, the signal amplification module 400 includes: an operational amplifier 410, a second resistor R 2 , the third resistor R 3 , the fourth resistor R 4 And the fifth resistor R 5 ; The second resistor R 2 One end of the fourth resistor R 4 The second resistor R 2 The other end of the signal amplification module is used as the first port 401, and the third resistor R 3 One end of the fifth resistor R 5 is connected to the inverting input terminal of the operational amplifier 410, and the third resistor R 3 The other end of the signal amplification module is used as the second port 402, and the fifth resistor R 5 The other end is connected to the output end of the operational amplifier and serves as the third port 403 of the signal amplification module.

[0044] The operational amplifier and the second resistor, the third resistor, the fourth resistor, and the fifth resistor form a differential amplifier circuit. Since the current flowing through the parasitic resistance on the compensation inductor is very small, the signal needs to be amplified and then sent to the analog-to-digital conversion unit of the signal processing module through the second feedback port for analog-to-digital sampling.

[0045] like Figure 5 As shown, the signal processing module 500 includes: The analog-to-digital conversion unit 510 is used to determine a coupling control signal according to the output terminal signal of the operational amplifier 410, and to determine a pulse signal according to the output voltage, so that the driving unit 520 can determine a driving signal; The driving unit 520 is used to determine a driving signal according to the pulse signal determined by the analog-to-digital conversion unit 510.

[0046] Specifically, the analog-to-digital conversion unit 510 has: a first receiving port 511 , a second receiving port 512 , a first transmitting port 513 , and a second transmitting port 514 ; The driving unit 520 has: a pulse receiving port 521 and a driving transmission port 522; The first receiving port 511 serves as the first feedback port 501 , the second receiving port 512 serves as the second feedback port 502 , the first transmitting port 513 serves as the first output port 503 , the second transmitting port 514 is connected to the pulse receiving port 521 , and the driving transmitting port 522 serves as the second output port 504 .

[0047] Alternatively, if Figure 7 As shown, the switch unit 110 includes a first transistor T 1 and a diode D; The first transistor T 1 Having: a first transistor first electrode T 11 , the second electrode T of the first transistor 12 and the third electrode T of the first transistor 13 ; The first transistor first electrode T 11 As the driving input port 111, the second electrode T of the first transistor 12 Connect input voltage V IN , the third electrode of the first transistor T 13 Connected to the cathode of diode D, the anode of diode D is grounded.

[0048] Optionally, the first transistor is an N-MOSFET. The first electrode of the first transistor is a gate electrode, the second electrode of the first transistor is a drain electrode, and the third electrode of the first transistor is a source electrode.

[0049] Alternatively, if Figure 8 As shown, the driving receiving port 101 has a first receiving sub-port 1011 and a second receiving sub-port 1012; The switch unit 110 includes a second transistor T 2 and the third transistor T 3 ; The second transistor T 2 Having: a first electrode T of a second transistor 21 , the second transistor second electrode T 22 and the third electrode T of the second transistor23 ; The third transistor T 3 Having: a first electrode T of a third transistor 31 , the second electrode T of the third transistor 32 and the third electrode T of the third transistor 33 ; The first electrode T of the second transistor 21 As the first receiving sub-port 1011, the third electrode of the second transistor and the second electrode of the third transistor T 32 Connect the first electrode of the third transistor T 31 Acts as the second receiving subport 1012 .

[0050] Alternatively, if Fig. 9 As shown, the second transistor T 2 The third transistor T 3 All are N-MOSFETs. The first pole of the second transistor is the gate, the second pole of the second transistor is the drain, and the third pole of the second transistor is the source; the first pole of the third transistor is the gate, the second pole of the third transistor is the drain, and the third pole of the third transistor is the source.

[0051] The high level phases of the driving signals received by the first receiving sub-port 1011 and the second receiving sub-port 1012 are complementary.

[0052] Alternatively, if Fig.10 As shown, the second transistor T 2 is a P-MOSFET, the third transistor T 3 It is an N-MOSFET; the first pole of the second transistor is the gate, the second pole of the second transistor is the source, and the third pole of the second transistor is the drain; the first pole of the third transistor is the gate, the second pole of the third transistor is the drain, and the third pole of the third transistor is the source.

[0053] The high level phases of the driving signals received by the first receiving sub-port 1011 and the second receiving sub-port 1012 are the same.

[0054] Alternatively, if Figure 8 As shown, the second output port 504 includes a first drive output sub-port 5041 and a second drive output sub-port 5042; The first driving output sub-port 5041 is connected to the first receiving sub-port 1011 and is used to provide a driving signal to the second transistor; And the second driving output sub-port 5042 is connected to the second receiving sub-port 1012 for providing a driving signal to the third transistor.

[0055] Unless otherwise specified, the “connections” described in this application refer to electrical connections.

[0056] The output filter inductor in the conventional BUCK circuit is replaced by a transformer, the turns ratio between the primary side and the secondary side of the transformer is 1:1, the primary side of the transformer is connected between the switch unit and the voltage output port, and the secondary side is connected in series with a switch and a compensation inductor. The switch S is controlled by the analog-to-digital conversion unit in the signal processing module through the GPIO bus. When the switch is disconnected, the secondary side of the transformer is open, and the excitation inductance of the primary side of the transformer participates in the output filtering of the BUCK circuit, which is equivalent to a conventional BUCK circuit (i.e., a BUCK circuit with an inductor as the output filter inductor). When the switch is closed, the secondary side of the transformer and the compensation inductor form a closed loop, and the compensation inductor is converted to the primary side of the transformer as the load of the transformer, which is equivalent to the excitation inductance of the primary side of the transformer being connected in parallel with the compensation inductor, thereby reducing the inductance value of the output filter inductor of the BUCK circuit.

[0057] The output voltage of the branch current conversion circuit is connected to the analog-to-digital conversion unit of the signal processing module through the first feedback port for analog-to-digital sampling. According to the magnitude relationship between the output voltage and the voltage setting value, a pulse width modulation signal is sent through the driving unit to drive the switch unit.

[0058] In addition to signal sampling, the analog-to-digital conversion unit also performs the following logic: continuously sampling the output voltage at the sampling frequency through the first feedback port, and marking the series of voltage values ​​obtained by sampling as V 1 、V 2 ,…,V n , and calculate the absolute value of the rate of change of the output voltage:

[0059] When the signal processing module detects that the output voltage is close to the voltage setting value, it means that the load current does not change much and the system operates under steady-state conditions.

[0060] When the signal processing module detects that the absolute value of the error between the output voltage and the voltage setting value is greater than the first threshold, and the absolute value of the output voltage change rate is greater than the second threshold, it means that the load current has a large mutation, and the system will operate in a transient response state. The signal processing module stabilizes the output voltage by changing the duty cycle of the pulse width modulation signal. At the same time, the analog-to-digital conversion unit of the signal processing module controls the switch to close through the GPIO bus, and the secondary side of the transformer and the compensation inductor form a closed loop. Then the compensation inductor is converted to the primary side of the transformer as the load of the transformer, which is equivalent to the excitation inductance of the primary side of the transformer and the compensation inductor in parallel, reducing the inductance value of the output filter inductor of the DC conversion circuit. Due to the equivalent inductance value of the output filter inductor of the DC conversion circuit, the rate of change of the current flowing through the output filter inductor increases, and it only takes a shorter time to complete the adjustment of the load current, thereby reducing the fluctuation of the output voltage and improving the dynamic response of the DC conversion circuit. Under transient response conditions, the equivalent inductance of the primary side of the transformer and the compensation inductor after coupling will break the volt-second balance, so a DC current component will be generated on the compensation inductor, such as Fig.11 shown.

[0061] When the current of the output filter inductor is adjusted to the new load current, a new steady-state condition is achieved, such as Fig.11 t 1 At this time, the average voltage of the pulse width modulation signal loaded on the primary side of the transformer in one switching cycle is 0, and the average voltage induced on the secondary side of the transformer is also 0, so that the compensation inductor reaches volt-second balance in one switching cycle. However, due to the parasitic resistance of the compensation inductor, the parasitic resistance consumes energy, causing the DC current component of the compensation inductor to slowly approach 0, such as Fig.11 t 1 to 2 The analog-to-digital conversion unit of the signal processing module samples the current flowing through the compensation inductor. When it is detected that the current drops to 0, the switch is disconnected through the GPIO bus control, and the secondary side of the transformer is open-circuited. Then, only the excitation inductance on the primary side of the transformer participates in the output filtering of the DC conversion circuit, which is completely equivalent to the conventional BUCK circuit.

[0062] Fig.11 The timing diagram shows that the switch is only 0 ~t 2 The equivalent inductance of the output filter inductor decreases during this period, and the peak-to-peak value of the current flowing through the output filter inductor increases. However, this interval lasts for a short time, exceeding t 2 At this moment, the switch is disconnected, the secondary side of the transformer is open, and the peak-to-peak value of the inductor current drops back to the normal BUCK circuit.

[0063] The reason why the switch is disconnected when the compensation inductor current crosses zero is that if the switch is disconnected at a non-current zero-crossing point, a very large di / dt will be generated, and the energy of the compensation inductor will be discharged quickly, resulting in sparking.

[0064] In some other embodiments, an electronic device includes the DC conversion circuit described above.

[0065] Specifically, the DC conversion circuit includes: The switch topology module 100 is used to drive the input voltage V according to the driving signal received by the driving receiving port 101. IN Convert to target voltage; The switch topology module 100 includes a transformer 120, the primary side of the transformer 120 serves as an output filter inductor of the switch topology module 100, and when the transformer 120 is coupled with the inductor coupling module 200, the equivalent inductance of the output filter inductor is reduced to improve the current dynamic response of the DC conversion circuit; The inductive coupling module 200 is connected to the secondary side of the transformer 120, receives a coupling control signal through its coupling control port 201, and controls the coupling between the inductive coupling module 200 and the transformer 120 to reduce the equivalent inductance of the output filter inductor and improve the current dynamic response of the DC conversion circuit.

[0066] It should be noted that the DC conversion circuit referred to in the present application is a switch circuit including an output filter inductor. For ease of explanation, a BUCK circuit is used as an example for explanation.

[0067] The switch topology module 100 further comprises: a switch topology module first coupling port 103 and a switch topology module second coupling port 104; The inductive coupling module 200 further comprises: an inductive coupling module first coupling port 202 and an inductive coupling module second coupling port 203; The first coupling port 103 of the switch topology module is connected to the first coupling port 202 of the inductive coupling module, and the second coupling port 104 of the switch topology module is connected to the second coupling port 203 of the inductive coupling module.

[0068] The voltage output port 102 of the switch topology module 100 is used to output a preset voltage.

[0069] Specifically, the switch topology module 100 further includes a switch unit 110; The switch unit 110 has a driving input port 111 , a voltage input port 112 , and a switch unit output port 113 ; The driving input port 111 serves as the driving receiving port 101, the switching unit output port 113 is connected to the same-name end of the primary side of the transformer 120, the same-name end of the secondary side of the transformer 120 serves as the first coupling port 103 of the switching topology module, and the other end of the secondary side of the transformer 120 serves as the second coupling port 104 of the switching topology module.

[0070] The other end of the primary side of the transformer 120 serves as a voltage output port 102 .

[0071] Preferably, if Figure 2 As shown, the other end of the primary side of the transformer 120 is connected in series with a second capacitor C 2 Then ground.

[0072] like Figure 3 As shown, the inductive coupling module 200 includes: a coupling inductor L c and a switch S; The switch S has: a first switch port S 1 , switch second port S 2 And the third port of the switch S 3 ; Switch first port S 1 As the coupling control port 201, the switch second port S 2 As the first coupling port 202 of the inductive coupling module, the third port S of the switch 3 With coupled inductor L c One end is connected to ground, and the coupling inductor L c The other end serves as the second coupling port 203 of the inductive coupling module.

[0073] The DC conversion circuit also includes: The current sampling module 300 is used to collect the current flowing through the secondary side of the transformer 120 from the inductive coupling module 200; The signal amplification module 400 is used to amplify the collected current flowing through the secondary side of the transformer 120; The signal processing module 500 is used to transmit a control signal to the coupling control port 201 according to the amplified current signal on the secondary side of the transformer 120 , and to adjust the driving signal according to the output voltage.

[0074] The inductive coupling module 200 further has: a first detection port 204 and a second detection port 205; The current sampling module 300 has: a first sampling port 301 , a second sampling port 302 and a third sampling port 303 ; The signal amplifying module 400 has: a first signal amplifying module port 401 , a second signal amplifying module port 402 , and a third signal amplifying module port 403 ; The signal processing module 500 has: a first feedback port 501 , a second feedback port 502 , a first output port 503 and a second output port 504 ; The first detection port 204 is connected to the first sampling port 301, the second detection port 205 is connected to the second sampling port 302, the third sampling port 303 is connected to the first port 401 of the signal amplification module, the second port 402 of the signal amplification module is connected to the second detection port 205 of the inductive coupling module, the third port 403 of the signal amplification module is connected to the second feedback port 502, the first feedback port 501 is connected to the voltage output port 102 of the switch topology module, the first output port 503 is connected to the coupling control port 201, and the second output port 504 is connected to the drive receiving port 101.

[0075] like Figure 4 As shown, the current sampling module 300 includes: a first resistor R 1 And the first capacitor C 1 ; The first resistor R 1 One end of the first sampling port 301 is used as the first sampling port 301, and the first resistor R 1 The other end of the first capacitor C 1 One end of the first capacitor C is connected as the third sampling port 303. 1 The other end of the device serves as a second sampling port 302 .

[0076] After the first resistor and the second capacitor are connected in series, they are connected in parallel to the two ends of the compensation inductor, and current sampling is performed on the compensation inductor. The current sampling method is DCR (DC equivalent resistance) current sampling. Since the non-productive inductor can be equivalent to the series connection of an ideal inductor and a parasitic resistor, by adjusting the values ​​of the first capacitor and the first resistor, the voltage across the first capacitor can be equal to the voltage of the parasitic resistor, and the current value flowing through the compensation inductor is obtained by dividing the voltage value by the resistance value of the parasitic resistor.

[0077] Furthermore, the signal amplification module 400 includes: an operational amplifier 410, a second resistor R 2 , the third resistor R 3 , the fourth resistor R 4 And the fifth resistor R 5 ; The second resistor R 2 One end of the fourth resistor R 4 The second resistor R 2 The other end of the signal amplification module is used as the first port 401, and the third resistor R 3 One end of the fifth resistor R 5 is connected to the inverting input terminal of the operational amplifier 410, and the third resistor R3 The other end of the signal amplification module is used as the second port 402, and the fifth resistor R 5 The other end is connected to the output end of the operational amplifier and serves as the third port 403 of the signal amplification module.

[0078] The operational amplifier and the second resistor, the third resistor, the fourth resistor, and the fifth resistor form a differential amplifier circuit. Since the current flowing through the parasitic resistance on the compensation inductor is very small, the signal needs to be amplified and then sent to the analog-to-digital conversion unit of the signal processing module through the second feedback port for analog-to-digital sampling.

[0079] like Figure 5 As shown, the signal processing module 500 includes: The analog-to-digital conversion unit 510 is used to determine a coupling control signal according to the output terminal signal of the operational amplifier 410, and to determine a pulse signal according to the output voltage, so that the driving unit 520 can determine a driving signal; The driving unit 520 is used to determine a driving signal according to the pulse signal determined by the analog-to-digital conversion unit 510.

[0080] Specifically, the analog-to-digital conversion unit 510 has: a first receiving port 511 , a second receiving port 512 , a first transmitting port 513 , and a second transmitting port 514 ; The driving unit 520 has: a pulse receiving port 521 and a driving transmission port 522; The first receiving port 511 serves as the first feedback port 501 , the second receiving port 512 serves as the second feedback port 502 , the first transmitting port 513 serves as the first output port 503 , the second transmitting port 514 is connected to the pulse receiving port 521 , and the driving transmitting port 522 serves as the second output port 504 .

[0081] Alternatively, if Figure 7 As shown, the switch unit 110 includes a first transistor T 1 and a diode D; The first transistor T 1 Having: a first transistor first electrode T 11 , the second electrode T of the first transistor 12 and the third electrode T of the first transistor 13 ; The first transistor first electrode T 11 As the driving input port 111, the second electrode T of the first transistor 12 Connect input voltage V IN , the third electrode of the first transistor T 13 Connected to the cathode of diode D, the anode of diode D is grounded.

[0082] Alternatively, if Figure 8As shown, the driving receiving port 101 has a first receiving sub-port 1011 and a second receiving sub-port 1012; The switch unit 110 includes a second transistor T 2 and the third transistor T 3 ; The second transistor T 2 Having: a first electrode T of a second transistor 21 , the second transistor second electrode T 22 and the third electrode T of the second transistor 23 ; The third transistor T 3 Having: a first electrode T of a third transistor 31 , the second electrode T of the third transistor 32 and the third electrode T of the third transistor 33 ; The first electrode T of the second transistor 21 As the first receiving sub-port 1011, the third electrode of the second transistor and the second electrode of the third transistor T 32 Connect the first electrode of the third transistor T 31 Acts as the second receiving subport 1012 .

[0083] Alternatively, if Fig. 9 As shown, the second transistor T 2 The third transistor T 3 All are N-MOSFET; The high level phases of the driving signals received by the first receiving sub-port 1011 and the second receiving sub-port 1012 are complementary.

[0084] Alternatively, if Fig.10 As shown, the second transistor T 2 is a P-MOSFET, the third transistor T 3 N-MOSFET; The high level phases of the driving signals received by the first receiving sub-port 1011 and the second receiving sub-port 1012 are the same.

[0085] Alternatively, if Figure 8 As shown, the second output port 504 includes a first drive output sub-port 5041 and a second drive output sub-port 5042; The first driving output sub-port 5041 is connected to the first receiving sub-port 1011 and is used to provide a driving signal to the second transistor; And the second driving output sub-port 5042 is connected to the second receiving sub-port 1012 for providing a driving signal to the third transistor.

[0086] Unless otherwise specified, the “connections” described in this application refer to electrical connections.

[0087] The output filter inductor in the conventional BUCK circuit is replaced by a transformer, the turns ratio between the primary side and the secondary side of the transformer is 1:1, the primary side of the transformer is connected between the switch unit and the voltage output port, and the secondary side is connected in series with a switch and a compensation inductor. The switch S is controlled by the analog-to-digital conversion unit in the signal processing module through the GPIO bus. When the switch is disconnected, the secondary side of the transformer is open, and the excitation inductance of the primary side of the transformer participates in the output filtering of the BUCK circuit, which is equivalent to a conventional BUCK circuit (i.e., a BUCK circuit with an inductor as the output filter inductor). When the switch is closed, the secondary side of the transformer and the compensation inductor form a closed loop, and the compensation inductor is converted to the primary side of the transformer as the load of the transformer, which is equivalent to the excitation inductance of the primary side of the transformer being connected in parallel with the compensation inductor, thereby reducing the inductance value of the output filter inductor of the BUCK circuit.

[0088] The output voltage of the branch current conversion circuit is connected to the analog-to-digital conversion unit of the signal processing module through the first feedback port for analog-to-digital sampling. According to the magnitude relationship between the output voltage and the voltage setting value, a pulse width modulation signal is sent through the driving unit to drive the switch unit.

[0089] In addition to signal sampling, the analog-to-digital conversion unit also performs the following logic: continuously sampling the output voltage at the sampling frequency through the first feedback port, and marking the series of voltage values ​​obtained by sampling as V 1 、V 2 ,…,V n , and calculate the absolute value of the rate of change of the output voltage:

[0090] When the signal processing module detects that the output voltage is close to the voltage setting value, it means that the load current does not change much and the system operates under steady-state conditions.

[0091] When the signal processing module detects that the absolute value of the error between the output voltage and the voltage setting value is greater than the first threshold, and the absolute value of the output voltage change rate is greater than the second threshold, it means that the load current has a large mutation, and the system will operate in a transient response state. The signal processing module stabilizes the output voltage by changing the duty cycle of the pulse width modulation signal. At the same time, the analog-to-digital conversion unit of the signal processing module controls the switch to close through the GPIO bus, and the secondary side of the transformer and the compensation inductor form a closed loop. Then the compensation inductor is converted to the primary side of the transformer as the load of the transformer, which is equivalent to the excitation inductance of the primary side of the transformer and the compensation inductor in parallel, reducing the inductance value of the output filter inductor of the DC conversion circuit. Due to the equivalent inductance value of the output filter inductor of the DC conversion circuit, the rate of change of the current flowing through the output filter inductor increases, and it only takes a shorter time to complete the adjustment of the load current, thereby reducing the fluctuation of the output voltage and improving the dynamic response of the DC conversion circuit. Under transient response conditions, the equivalent inductance of the primary side of the transformer and the compensation inductor after coupling will break the volt-second balance, so a DC current component will be generated on the compensation inductor, such as Fig.11 shown.

[0092] When the current of the output filter inductor is adjusted to the new load current, a new steady-state condition is achieved, such as Fig.11 t 1 At this time, the average voltage of the pulse width modulation signal loaded on the primary side of the transformer in one switching cycle is 0, and the average voltage induced on the secondary side of the transformer is also 0, so that the compensation inductor reaches volt-second balance in one switching cycle. However, due to the parasitic resistance of the compensation inductor, the parasitic resistance consumes energy, causing the DC current component of the compensation inductor to slowly approach 0, such as Fig.11 t 1 to 2 The analog-to-digital conversion unit of the signal processing module samples the current flowing through the compensation inductor. When it is detected that the current drops to 0, the switch is disconnected through the GPIO bus control, and the secondary side of the transformer is open-circuited. Then, only the excitation inductance on the primary side of the transformer participates in the output filtering of the DC conversion circuit, which is completely equivalent to the conventional BUCK circuit.

[0093] Fig.11 The timing diagram shows that the switch is only 0 ~t 2 The equivalent inductance of the output filter inductor decreases during this period, and the peak-to-peak value of the current flowing through the output filter inductor increases. However, this interval lasts for a short time, exceeding t 2 At this moment, the switch is disconnected, the secondary side of the transformer is open, and the peak-to-peak value of the inductor current drops back to the normal BUCK circuit.

[0094] The reason why the switch is disconnected when the compensation inductor current crosses zero is that if the switch is disconnected at a non-current zero-crossing point, a very large di / dt will be generated, and the energy of the compensation inductor will be discharged quickly, resulting in sparking.

[0095] In some other embodiments, a server includes the DC conversion circuit described above.

[0096] Specifically, the DC conversion circuit includes: The switch topology module 100 is used to drive the input voltage V according to the driving signal received by the driving receiving port 101. IN Convert to target voltage; The switch topology module 100 includes a transformer 120, the primary side of the transformer 120 serves as an output filter inductor of the switch topology module 100, and when the transformer 120 is coupled with the inductor coupling module 200, the equivalent inductance of the output filter inductor is reduced to improve the current dynamic response of the DC conversion circuit; The inductive coupling module 200 is connected to the secondary side of the transformer 120, receives a coupling control signal through its coupling control port 201, and controls the coupling between the inductive coupling module 200 and the transformer 120 to reduce the equivalent inductance of the output filter inductor and improve the current dynamic response of the DC conversion circuit.

[0097] It should be noted that the DC conversion circuit referred to in the present application is a switch circuit including an output filter inductor. For ease of explanation, a BUCK circuit is used as an example for explanation.

[0098] The switch topology module 100 further comprises: a switch topology module first coupling port 103 and a switch topology module second coupling port 104; The inductive coupling module 200 further comprises: an inductive coupling module first coupling port 202 and an inductive coupling module second coupling port 203; The first coupling port 103 of the switch topology module is connected to the first coupling port 202 of the inductive coupling module, and the second coupling port 104 of the switch topology module is connected to the second coupling port 203 of the inductive coupling module.

[0099] The voltage output port 102 of the switch topology module 100 is used to output a preset voltage.

[0100] Specifically, the switch topology module 100 further includes a switch unit 110; The switch unit 110 has a driving input port 111 , a voltage input port 112 , and a switch unit output port 113 ; The driving input port 111 serves as the driving receiving port 101, the switching unit output port 113 is connected to the same-name end of the primary side of the transformer 120, the same-name end of the secondary side of the transformer 120 serves as the first coupling port 103 of the switching topology module, and the other end of the secondary side of the transformer 120 serves as the second coupling port 104 of the switching topology module.

[0101] The other end of the primary side of the transformer 120 serves as a voltage output port 102 .

[0102] Preferably, if Figure 2 As shown, the other end of the primary side of the transformer 120 is connected in series with a second capacitor C 2 Then ground.

[0103] like Figure 3 As shown, the inductive coupling module 200 includes: a coupling inductor L c and a switch S; The switch S has: a first switch port S 1 , switch second port S 2 And the third port of the switch S 3 ; Switch first port S 1 As the coupling control port 201, the switch second port S 2 As the first coupling port 202 of the inductive coupling module, the third port S of the switch 3 With coupled inductor L c One end is connected to ground, and the coupling inductor L c The other end serves as the second coupling port 203 of the inductive coupling module.

[0104] The DC conversion circuit also includes: The current sampling module 300 is used to collect the current flowing through the secondary side of the transformer 120 from the inductive coupling module 200; The signal amplification module 400 is used to amplify the collected current flowing through the secondary side of the transformer 120; The signal processing module 500 is used to transmit a control signal to the coupling control port 201 according to the amplified current signal on the secondary side of the transformer 120 , and to adjust the driving signal according to the output voltage.

[0105] The inductive coupling module 200 further has: a first detection port 204 and a second detection port 205; The current sampling module 300 has: a first sampling port 301 , a second sampling port 302 and a third sampling port 303 ; The signal amplifying module 400 has: a first signal amplifying module port 401 , a second signal amplifying module port 402 , and a third signal amplifying module port 403 ; The signal processing module 500 has: a first feedback port 501 , a second feedback port 502 , a first output port 503 and a second output port 504 ; The first detection port 204 is connected to the first sampling port 301, the second detection port 205 is connected to the second sampling port 302, the third sampling port 303 is connected to the first port 401 of the signal amplification module, the second port 402 of the signal amplification module is connected to the second detection port 205 of the inductive coupling module, the third port 403 of the signal amplification module is connected to the second feedback port 502, the first feedback port 501 is connected to the voltage output port 102 of the switch topology module, the first output port 503 is connected to the coupling control port 201, and the second output port 504 is connected to the drive receiving port 101.

[0106] like Figure 4 As shown, the current sampling module 300 includes: a first resistor R 1 And the first capacitor C 1 ; The first resistor R 1 One end of the first sampling port 301 is used as the first sampling port 301, and the first resistor R 1 The other end of the first capacitor C 1 One end of the first capacitor C is connected as the third sampling port 303. 1 The other end of the device serves as a second sampling port 302 .

[0107] After the first resistor and the second capacitor are connected in series, they are connected in parallel to the two ends of the compensation inductor, and current sampling is performed on the compensation inductor. The current sampling method is DCR (DC equivalent resistance) current sampling. Since the non-productive inductor can be equivalent to the series connection of an ideal inductor and a parasitic resistor, by adjusting the values ​​of the first capacitor and the first resistor, the voltage across the first capacitor can be equal to the voltage of the parasitic resistor, and the current value flowing through the compensation inductor is obtained by dividing the voltage value by the resistance value of the parasitic resistor.

[0108] Furthermore, the signal amplification module 400 includes: an operational amplifier 410, a second resistor R 2 , the third resistor R 3 , the fourth resistor R 4 And the fifth resistor R 5 ; The second resistor R 2 One end of the fourth resistor R 4 The second resistor R 2 The other end of the signal amplification module is used as the first port 401, and the third resistor R 3 One end of the fifth resistor R 5 is connected to the inverting input terminal of the operational amplifier 410, and the third resistor R3 The other end of the signal amplification module is used as the second port 402, and the fifth resistor R 5 The other end is connected to the output end of the operational amplifier and serves as the third port 403 of the signal amplification module.

[0109] The operational amplifier and the second resistor, the third resistor, the fourth resistor, and the fifth resistor form a differential amplifier circuit. Since the current flowing through the parasitic resistance on the compensation inductor is very small, the signal needs to be amplified and then sent to the analog-to-digital conversion unit of the signal processing module through the second feedback port for analog-to-digital sampling.

[0110] like Figure 5 As shown, the signal processing module 500 includes: The analog-to-digital conversion unit 510 is used to determine a coupling control signal according to the output terminal signal of the operational amplifier 410, and to determine a pulse signal according to the output voltage, so that the driving unit 520 can determine a driving signal; The driving unit 520 is used to determine a driving signal according to the pulse signal determined by the analog-to-digital conversion unit 510.

[0111] Specifically, the analog-to-digital conversion unit 510 has: a first receiving port 511 , a second receiving port 512 , a first transmitting port 513 , and a second transmitting port 514 ; The driving unit 520 has: a pulse receiving port 521 and a driving transmission port 522; The first receiving port 511 serves as the first feedback port 501 , the second receiving port 512 serves as the second feedback port 502 , the first transmitting port 513 serves as the first output port 503 , the second transmitting port 514 is connected to the pulse receiving port 521 , and the driving transmitting port 522 serves as the second output port 504 .

[0112] Alternatively, if Figure 7 As shown, the switch unit 110 includes a first transistor T 1 and a diode D; The first transistor T 1 Having: a first transistor first electrode T 11 , the second electrode T of the first transistor 12 and the third electrode T of the first transistor 13 ; The first transistor first electrode T 11 As the driving input port 111, the second electrode T of the first transistor 12 Connect input voltage V IN , the third electrode of the first transistor T 13 Connected to the cathode of diode D, the anode of diode D is grounded.

[0113] Alternatively, if Figure 8As shown, the driving receiving port 101 has a first receiving sub-port 1011 and a second receiving sub-port 1012; The switch unit 110 includes a second transistor T 2 and the third transistor T 3 ; The second transistor T 2 Having: a first electrode T of a second transistor 21 , the second transistor second electrode T 22 and the third electrode T of the second transistor 23 ; The third transistor T 3 Having: a first electrode T of a third transistor 31 , the second electrode T of the third transistor 32 and the third electrode T of the third transistor 33 ; The first electrode T of the second transistor 21 As the first receiving sub-port 1011, the third electrode of the second transistor and the second electrode of the third transistor T 32 Connect the first electrode of the third transistor T 31 Acts as the second receiving subport 1012 .

[0114] Alternatively, if Fig. 9 As shown, the second transistor T 2 The third transistor T 3 All are N-MOSFET; The high level phases of the driving signals received by the first receiving sub-port 1011 and the second receiving sub-port 1012 are complementary.

[0115] Alternatively, if Fig.10 As shown, the second transistor T 2 is a P-MOSFET, the third transistor T 3 N-MOSFET; The high level phases of the driving signals received by the first receiving sub-port 1011 and the second receiving sub-port 1012 are the same.

[0116] Alternatively, if Figure 8 As shown, the second output port 504 includes a first drive output sub-port 5041 and a second drive output sub-port 5042; The first driving output sub-port 5041 is connected to the first receiving sub-port 1011 and is used to provide a driving signal to the second transistor; And the second driving output sub-port 5042 is connected to the second receiving sub-port 1012 for providing a driving signal to the third transistor.

[0117] Unless otherwise specified, the “connections” described in this application refer to electrical connections.

[0118] The output filter inductor in the conventional BUCK circuit is replaced by a transformer, the turns ratio between the primary side and the secondary side of the transformer is 1:1, the primary side of the transformer is connected between the switch unit and the voltage output port, and the secondary side is connected in series with a switch and a compensation inductor. The switch S is controlled by the analog-to-digital conversion unit in the signal processing module through the GPIO bus. When the switch is disconnected, the secondary side of the transformer is open, and the excitation inductance of the primary side of the transformer participates in the output filtering of the BUCK circuit, which is equivalent to a conventional BUCK circuit (i.e., a BUCK circuit with an inductor as the output filter inductor). When the switch is closed, the secondary side of the transformer and the compensation inductor form a closed loop, and the compensation inductor is converted to the primary side of the transformer as the load of the transformer, which is equivalent to the excitation inductance of the primary side of the transformer being connected in parallel with the compensation inductor, thereby reducing the inductance value of the output filter inductor of the BUCK circuit.

[0119] The output voltage of the branch current conversion circuit is connected to the analog-to-digital conversion unit of the signal processing module through the first feedback port for analog-to-digital sampling. According to the magnitude relationship between the output voltage and the voltage setting value, a pulse width modulation signal is sent through the driving unit to drive the switch unit.

[0120] In addition to signal sampling, the analog-to-digital conversion unit also performs the following logic: through the first feedback port, the sampling frequency , continuously sample the output voltage, and mark the series of voltage values ​​obtained by sampling as V 1 、V 2 ,…,V n , and calculate the absolute value of the rate of change of the output voltage:

[0121] When the signal processing module detects that the output voltage is close to the voltage setting value, it means that the load current does not change much and the system operates under steady-state conditions.

[0122] When the signal processing module detects that the absolute value of the error between the output voltage and the voltage setting value is greater than the first threshold, and the absolute value of the output voltage change rate is greater than the second threshold, it means that the load current has a large mutation, and the system will operate in a transient response state. The signal processing module stabilizes the output voltage by changing the duty cycle of the pulse width modulation signal. At the same time, the analog-to-digital conversion unit of the signal processing module controls the switch to close through the GPIO bus, and the secondary side of the transformer and the compensation inductor form a closed loop. Then the compensation inductor is converted to the primary side of the transformer as the load of the transformer, which is equivalent to the excitation inductance of the primary side of the transformer and the compensation inductor in parallel, reducing the inductance value of the output filter inductor of the DC conversion circuit. Due to the equivalent inductance value of the output filter inductor of the DC conversion circuit, the rate of change of the current flowing through the output filter inductor increases, and it only takes a shorter time to complete the adjustment of the load current, thereby reducing the fluctuation of the output voltage and improving the dynamic response of the DC conversion circuit. Under transient response conditions, the equivalent inductance of the primary side of the transformer and the compensation inductor after coupling will break the volt-second balance, so a DC current component will be generated on the compensation inductor, such as Fig.11 shown.

[0123] When the current of the output filter inductor is adjusted to the new load current, a new steady-state condition is achieved, such as Fig.11 t 1 At this time, the average voltage of the pulse width modulation signal loaded on the primary side of the transformer in one switching cycle is 0, and the average voltage induced on the secondary side of the transformer is also 0, so that the compensation inductor reaches volt-second balance in one switching cycle. However, due to the parasitic resistance of the compensation inductor, the parasitic resistance consumes energy, causing the DC current component of the compensation inductor to slowly approach 0, such as Fig.11 t 1 to 2 The analog-to-digital conversion unit of the signal processing module samples the current flowing through the compensation inductor. When it is detected that the current drops to 0, the switch is disconnected through the GPIO bus control, and the secondary side of the transformer is open-circuited. Then, only the excitation inductance on the primary side of the transformer participates in the output filtering of the DC conversion circuit, which is completely equivalent to the conventional BUCK circuit.

[0124] Fig.11 The timing diagram shows that the switch is only 0 ~t 2 The equivalent inductance of the output filter inductor decreases during this period, and the peak-to-peak value of the current flowing through the output filter inductor increases. However, this interval lasts for a short time, exceeding t 2 At this moment, the switch is disconnected, the secondary side of the transformer is open, and the peak-to-peak value of the inductor current drops back to the normal BUCK circuit.

[0125] The reason why the switch is disconnected when the compensation inductor current crosses zero is that if the switch is disconnected at a non-current zero-crossing point, a very large di / dt will be generated, and the energy of the compensation inductor will be discharged quickly, resulting in sparking.

[0126] In some other embodiments, a DC conversion circuit control method is applied to the DC conversion circuit described above, including: In response to the absolute value of the difference between the output voltage and the preset voltage value exceeding the first threshold value, and the output voltage change rate exceeding the second threshold value, the drive signal is adjusted to restore the output voltage to the preset voltage value, and the coupling signal is used as the coupling control signal and transmitted to the coupling control port to couple the inductive coupling module with the transformer to reduce the equivalent inductance of the output filter inductor in the DC conversion circuit to improve the response speed of the DC conversion circuit.

[0127] The DC conversion circuit control method further includes: In response to the output voltage change rate not exceeding the second threshold value, and the absolute value of the difference between the output voltage and the preset voltage value exceeding the first threshold value, the driving signal is adjusted to restore the output voltage to the preset voltage value.

[0128] The DC conversion circuit control method further includes: In response to the DC current component of the compensation inductor dropping to 0, it is transmitted to the coupling control port, and the decoupling signal is used as the coupling control signal and transmitted to the coupling control port, so that the inductive coupling module is decoupled from the transformer, and the primary side of the transformer is used as the output filter inductor to reduce the output ripple.

[0129] The present invention takes a sudden and substantial increase in load current as an example, and describes a specific implementation method as follows: When the load current suddenly increases significantly, since the inductor current cannot change suddenly, the load current will be drawn from the output filter capacitor (i.e., the second capacitor), causing the output voltage to drop rapidly and the output voltage change rate to be negative.

[0130] like Fig.11 Medium 0At this moment, the signal processing module detects that the absolute value of the error between the output voltage and the voltage setting value is greater than the first threshold, and the absolute value of the output voltage change rate is also greater than the second threshold, indicating that the load current has a large mutation. The system will operate in a transient response state, and the signal processing module stabilizes the output voltage by changing the duty cycle of the pulse width modulation signal. At the same time, the analog-to-digital conversion unit of the signal processing module controls the switch to close through the GPIO bus, and the secondary side of the transformer and the compensation inductor form a closed loop. Then the compensation inductor is converted to the primary side of the transformer as the load of the transformer, which is equivalent to the excitation inductance of the primary side of the transformer and the compensation inductor in parallel, reducing the inductance value of the output filter inductor of the DC conversion circuit. Due to the equivalent inductance value of the output filter inductor of the DC conversion circuit, the rate of change of the current flowing through the output filter inductor increases, and it only takes a shorter time to complete the adjustment of the load current, thereby reducing the fluctuation of the output voltage and improving the dynamic response of the DC conversion circuit. Under transient response conditions, the equivalent inductance of the primary side of the transformer and the compensation inductor after coupling will break the volt-second balance, so a DC current component will be generated on the compensation inductor, such as Fig.11 shown.

[0131] When the current of the output filter inductor is adjusted to the new load current, a new steady-state condition is achieved, such as Fig.11 t 1 At this time, the average voltage of the pulse width modulation signal loaded on the primary side of the transformer in one switching cycle is 0, and the average voltage induced on the secondary side of the transformer is also 0, so that the compensation inductor reaches volt-second balance in one switching cycle. However, due to the parasitic resistance of the compensation inductor, the parasitic resistance consumes energy, causing the DC current component of the compensation inductor to slowly approach 0, such as Fig.11 t 1 to 2 The analog-to-digital conversion unit of the signal processing module samples the current flowing through the compensation inductor. When it is detected that the current drops to 0, the switch is disconnected through the GPIO bus control, and the secondary side of the transformer is open-circuited. Then, only the excitation inductance on the primary side of the transformer participates in the output filtering of the DC conversion circuit, which is completely equivalent to the conventional BUCK circuit.

[0132] Fig.11 The timing diagram shows that the switch is only 0 ~t 2 The equivalent inductance of the output filter inductor decreases during this period, and the peak-to-peak value of the current flowing through the output filter inductor increases. However, this interval lasts for a short time, exceeding t 2 At this moment, the switch is disconnected, the secondary side of the transformer is open, and the peak-to-peak value of the inductor current drops back to the normal BUCK circuit.

[0133] By using the primary side of the transformer as the output filter inductor and using a switch on the secondary side of the transformer to control the compensation inductor to couple with the primary side of the transformer, the equivalent inductance of the output filter inductor can be reduced when the compensation inductor is coupled with the primary side of the transformer, thereby improving the dynamic response capability of the DC conversion circuit; and after the DC conversion circuit reaches a steady state, the compensation inductor is decoupled from the primary side of the transformer, and a larger output filter inductor is used to reduce the ripple at the output end and improve the conversion efficiency of the DC conversion circuit.

[0134] All the above optional technical solutions can be arbitrarily combined to form optional embodiments of the present application, which will not be described one by one here.

[0135] Note that the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments and substitutions can be made to those skilled in the art without departing from the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of this application should be included in the scope of protection of this application. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may also include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A DC conversion circuit, characterized in that: include: A switch topology module, used for converting an input voltage into a target voltage according to a driving signal received by a driving receiving port thereof; The switch topology module includes a transformer, the primary side of the transformer serves as an output filter inductor of the switch topology module, and when the transformer is coupled with the inductor coupling module, the equivalent inductance of the output filter inductor is reduced to improve the current dynamic response of the DC conversion circuit; The inductive coupling module is connected to the secondary side of the transformer, receives a coupling control signal through its coupling control port, and controls the coupling between the inductive coupling module and the transformer to reduce the equivalent inductance of the output filter inductor and improve the current dynamic response of the DC conversion circuit.

2. The DC conversion circuit according to claim 1, characterized in that: The switch topology module further comprises: a switch topology module first coupling port and a switch topology module second coupling port; The inductive coupling module further comprises: a first coupling port of the inductive coupling module and a second coupling port of the inductive coupling module; The first coupling port of the switch topology module is connected to the first coupling port of the inductive coupling module, and the second coupling port of the switch topology module is connected to the second coupling port of the inductive coupling module.

3. The DC conversion circuit according to claim 1, characterized in that: The switch topology module also includes a switch unit; The switch unit has a drive input port, a voltage input port and a switch unit output port; The driving input port serves as the driving receiving port, the switching unit output port is connected to the same-name end of the primary side of the transformer, the same-name end of the secondary side of the transformer serves as the first coupling port of the switch topology module, and the other end of the secondary side of the transformer serves as the second coupling port of the switch topology module.

4. The DC conversion circuit according to claim 1, characterized in that: The inductive coupling module includes: a coupled inductor and a switch; The switch has: a first switch port, a second switch port and a third switch port; The first port of the switch serves as the coupling control port, the second port of the switch serves as the first coupling port of the inductive coupling module, the third port of the switch is connected to one end of the coupling inductor and then grounded, and the other end of the coupling inductor serves as the second coupling port of the inductive coupling module.

5. The DC conversion circuit according to claim 1, characterized in that: The DC conversion circuit also includes: A current sampling module, used for collecting the current flowing through the secondary side of the transformer from the inductive coupling module; A signal amplification module, used to amplify the collected current flowing through the secondary side of the transformer; The signal processing module is used to transmit a control signal to the coupling control port according to the amplified current signal on the secondary side of the transformer, and to adjust the driving signal according to the output voltage.

6. The DC conversion circuit according to claim 5, characterized in that: The inductive coupling module further comprises: a first detection port and a second detection port; The current sampling module has: a first sampling port, a second sampling port and a third sampling port; The signal amplification module has: a first port of the signal amplification module, a second port of the signal amplification module and a third port of the signal amplification module; The signal processing module has: a first feedback port, a second feedback port, a first output port and a second output port; The first detection port is connected to the first sampling port, the second detection port is connected to the second sampling port, the third sampling port is connected to the first port of the signal amplification module, the second port of the signal amplification module is connected to the second detection port of the inductive coupling module, the third port of the signal amplification module is connected to the second feedback port, the first feedback port is connected to the voltage output port of the switch topology module, the first output port is connected to the coupling control port, and the second output port is connected to the drive receiving port.

7. The DC conversion circuit according to claim 5, characterized in that: The current sampling module includes: a first resistor and a first capacitor; One end of the first resistor serves as a first sampling port, the other end of the first resistor is connected to one end of the first capacitor and serves as a third sampling port, and the other end of the first capacitor serves as a second sampling port.

8. The DC conversion circuit according to claim 5, characterized in that: The signal amplification module includes: an operational amplifier, a second resistor, a third resistor, a fourth resistor and a fifth resistor; One end of the second resistor is connected to one end of the fourth resistor and then connected to the non-inverting input terminal of the operational amplifier, the other end of the second resistor serves as the first port of the signal amplification module, one end of the third resistor is connected to one end of the fifth resistor and then connected to the inverting input terminal of the operational amplifier, the other end of the third resistor serves as the second port of the signal amplification module, and the other end of the fifth resistor is connected to the output terminal of the operational amplifier and then serves as the third port of the signal amplification module.

9. The DC conversion circuit according to claim 5, characterized in that: The signal processing module comprises: The analog-to-digital conversion unit is used to determine the coupling control signal according to the output terminal signal of the operational amplifier, and determine the pulse signal according to the output voltage, so that the driving unit can determine the driving signal; The driving unit is used to determine the driving signal according to the pulse signal determined by the analog-to-digital conversion unit.

10. The DC conversion circuit according to claim 9, characterized in that: The analog-to-digital conversion unit has: a first receiving port, a second receiving port, a first transmitting port and a second transmitting port; The driving unit has: a pulse receiving port and a driving transmission port; The first receiving port serves as a first feedback port, the second receiving port serves as a second feedback port, the first transmission port serves as a first output port, the second transmission port is connected to the pulse receiving port, and the driving transmission port serves as a second output port.

11. The DC conversion circuit according to claim 3, characterized in that: The switch unit includes a first transistor and a diode; The first transistor comprises: a first transistor first electrode, a first transistor second electrode and a first transistor third electrode; The first electrode of the first transistor serves as the driving input port, the second electrode of the first transistor is connected to the input voltage, the third electrode of the first transistor is connected to the cathode of the diode, and the anode of the diode is grounded.

12. The DC conversion circuit according to claim 3, characterized in that: The driving receiving port has a first receiving sub-port and a second receiving sub-port; The switch unit includes a second transistor and a third transistor; The second transistor comprises: a second transistor first electrode, a second transistor second electrode and a second transistor third electrode; The third transistor comprises: a third transistor first electrode, a third transistor second electrode and a third transistor third electrode; The first electrode of the second transistor serves as the first receiving sub-port, the third electrode of the second transistor is connected to the second electrode of the third transistor, and the first electrode of the third transistor serves as the second receiving sub-port.

13. The DC conversion circuit according to claim 12, characterized in that: The second transistor and the third transistor are both N-MOSFETs; The high level phases of the driving signals received by the first receiving sub-port and the second receiving sub-port are complementary.

14. The DC conversion circuit according to claim 12, characterized in that: The second transistor is a P-MOSFET, and the third transistor is an N-MOSFET; The high level phases of the driving signals received by the first receiving sub-port and the second receiving sub-port are the same.

15. The DC conversion circuit according to claim 13 or 14, characterized in that: The second output port includes a first driver output sub-port and a second driver output sub-port; The first drive output sub-port is connected to the first receiving sub-port and is used to provide a drive signal to the second transistor; And the second driving output sub-port is connected to the second receiving sub-port for providing a driving signal to the third transistor.

16. An electronic device, characterized in that The invention comprises the DC conversion circuit as described in any one of claims 1 to 15.

17. A server, characterized in that The invention comprises the DC conversion circuit as described in any one of claims 1 to 15.

18. A DC conversion circuit control method, characterized in that: The DC conversion circuit according to any one of claims 1 to 15 comprises: In response to the absolute value of the difference between the output voltage and the preset voltage value exceeding the first threshold value, and the output voltage change rate exceeding the second threshold value, the drive signal is adjusted to restore the output voltage to the preset voltage value, and the coupling signal is used as the coupling control signal and transmitted to the coupling control port to couple the inductive coupling module with the transformer to reduce the equivalent inductance of the output filter inductor in the DC conversion circuit and improve the response speed of the DC conversion circuit.

19. The DC conversion circuit control method according to claim 18, characterized in that: The method further comprises: In response to the output voltage change rate not exceeding the second threshold value, and the absolute value of the difference between the output voltage and the preset voltage value exceeding the first threshold value, the driving signal is adjusted to restore the output voltage to the preset voltage value.

20. The DC conversion circuit control method according to claim 18, characterized in that: The method further comprises: In response to the DC current component of the compensation inductor dropping to 0, it is transmitted to the coupling control port, and the decoupling signal is used as the coupling control signal and transmitted to the coupling control port, so that the inductive coupling module is decoupled from the transformer, and the primary side of the transformer is used as the output filter inductor to reduce the output ripple.

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