Voltage conversion circuit and power supply assembly

Abstract

The invention discloses a voltage conversion circuit and a power supply assembly. The voltage conversion circuit comprises a power module, a magnetic element, a first gain unit and an output capacitor. A third end of the magnetic element is used as a second power supply input end of the voltage conversion circuit, and the magnetic element can store or release energy; the first gain unit comprises a first charge storage element, the second end of the first gain unit is electrically connected with the first end of the magnetic element, and the third end of the first gain unit is electrically connected with the first end of the output capacitor; the first gain unit can conduct the second end of the first charge storage element and the second end of the first gain unit based on the control of the first switch control signal, and conduct the second end of the first charge storage element and the third end of the first gain unit based on the control of the second switch control signal; the second end of the output capacitor is electrically connected with the second power input end of the voltage conversion circuit. According to the invention, a relatively high voltage transformation ratio can be realized by utilizing a relatively low switch duty ratio.

Description

Technical Field

[0001] The present invention relates to the technical field of voltage conversion, and in particular to a voltage conversion circuit and a power supply component. Background Art

[0002] The voltage conversion circuit can transform the voltage generated by the power supply so that the subsequent circuit can obtain the required voltage. Therefore, the voltage conversion circuit with a high voltage conversion ratio plays an important role as a core component of power conversion.

[0003] In the related art, a boost voltage conversion circuit is used to achieve voltage conversion; however, when the voltage conversion ratio increases, the switch duty cycle in the boost voltage conversion circuit will reach a very high level, causing a serious reverse recovery current spike in the output diode. In addition, the extremely high switch duty cycle will also lead to reduced power supply efficiency and reliability. Summary of the invention

[0004] The present invention provides a voltage conversion circuit and a power supply component, which can realize a higher voltage conversion ratio by utilizing a lower switch duty cycle.

[0005] According to one aspect of the present invention, a voltage conversion circuit is provided, the voltage conversion circuit comprising: a power module, a magnetic element, a first gain unit and an output capacitor;

[0006] The input end of the power module serves as the first power input end of the voltage conversion circuit, the first output end of the power module is electrically connected to the first end of the magnetic element, the second output end of the power module is electrically connected to the second end of the magnetic element, and the power module can be controlled to conduct its input end with its first output end based on a first power control signal, and to conduct its input end with its second output end based on a second power control signal;

[0007] The third end of the magnetic element serves as the second power input end of the voltage conversion circuit, and the magnetic element can store or release energy;

[0008] The first gain unit includes a first charge storage element, a first end of the first charge storage element serves as a first end of the first gain unit and is electrically connected to a second end of the magnetic element, a second end of the first gain unit is electrically connected to a first end of the magnetic element, a third end of the first gain unit is electrically connected to a first end of the output capacitor, and the first gain unit is capable of conducting the second end of the first charge storage element with the second end of the first gain unit based on a control of a first switch control signal, and conducting the second end of the first charge storage element with the third end of the first gain unit based on a control of a second switch control signal;

[0009] The second end of the output capacitor is electrically connected to the second power input end of the voltage conversion circuit.

[0010] Optionally, the first gain unit further includes: a first switch element and a second switch element;

[0011] The first end of the first switch element is electrically connected to the second end of the first charge storage element, the second end of the first switch element is electrically connected to the second end of the first gain unit, and the control end of the first switch element is connected to the first switch control signal;

[0012] The first end of the second switch element is electrically connected to the second end of the first charge storage element, the second end of the second switch element is electrically connected to the third end of the first gain unit, and the control end of the second switch element is connected to the second switch control signal.

[0013] Optionally, the first power control signal has the same duty cycle and period as the second power control signal, and a phase difference of the second power control signal with the first power control signal is 180 degrees;

[0014] The first switch control signal is inverted to the first power control signal; the second switch control signal is inverted to the second power control signal.

[0015] Optionally, the voltage conversion circuit further includes at least one stage of detachable second gain unit, the second gain unit includes a second charge storage element and a third charge storage element, the first end of the second charge storage element serves as the first end of the second gain unit, the first end of the third charge storage element serves as the third end of the second gain unit, and the second end of the third charge storage element serves as the fourth end of the second gain unit; the second gain unit is capable of conducting the second end of the second charge storage element with the second end of the second gain unit based on the control of the first switch control signal, and conducting the second end of the second charge storage element with the third end of the second gain unit based on the control of the second switch control signal;

[0016] When the voltage conversion circuit is configured to be connected to at least one stage of the second gain unit, the second end of the first gain unit is electrically connected to the first end of the magnetic element through the at least one stage of the second gain unit; wherein the first end of each stage of the second gain unit is electrically connected to the second end of the magnetic element, the second end of the first stage of the second gain unit is electrically connected to the first end of the magnetic element, and the fourth end of the first stage of the second gain unit is electrically connected to the second end of the first stage of the second gain unit;

[0017] The third end of the second gain unit is electrically connected to the second end of the second gain unit of the next stage, and the fourth end of the second gain unit is electrically connected to the fourth end of the second gain unit of the next stage, wherein the third end of the second gain unit of the last stage is electrically connected to the second end of the first gain unit, and the fourth end of the second gain unit of the last stage is suspended.

[0018] Optionally, the second gain unit further includes a third switch element and a fourth switch element, the first end of the third switch element is electrically connected to the second end of the second charge storage element, the second end of the third switch element is electrically connected to the second end of the second gain unit, and the control end of the third switch element is connected to the first switch control signal;

[0019] The first end of the fourth switch element is electrically connected to the second end of the second charge storage element, the second end of the fourth switch element is electrically connected to the third end of the second gain unit, and the control end of the fourth switch element is connected to the second switch control signal.

[0020] Optionally, the voltage conversion circuit also includes a digital hybrid control module, which is electrically connected to the output end of the voltage conversion circuit, and the digital hybrid control module is used to generate the first power control signal, the second power control signal, the first switch control signal and the second switch control signal according to the output voltage of the voltage conversion circuit.

[0021] Optionally, the digital hybrid control module includes:

[0022] A threshold comparison unit, a transient mode compensation control unit, a control mode selection unit, and a steady-state PID compensation control unit;

[0023] The threshold comparison unit is electrically connected to the output end of the voltage conversion circuit, and the threshold comparison unit is used to generate a comparison signal according to the output voltage of the voltage conversion circuit; the transient mode compensation control unit is electrically connected to the threshold comparison unit, and is used to generate a selection signal and a transient control signal according to the comparison signal, and the transient control signal is used to generate the first power control signal, the second power control signal, the first switch control signal, and the second switch control signal whose duty ratio is not higher than a preset upper limit or not lower than a preset lower limit;

[0024] The steady-state PID compensation control unit is electrically connected to the control mode selection unit, and the steady-state PID compensation control unit is used to generate a steady-state adjustment signal according to the output voltage, and the steady-state adjustment signal is used to generate the first steady-state power control signal, the second power control signal, the first switch control signal, and the second switch control signal;

[0025] The control mode selection unit is used to output the transient control signal or the steady-state regulation signal according to the selection signal.

[0026] Optionally, the digital hybrid control module also includes a dead zone setting unit, and the output end of the control mode selection unit is electrically connected to the dead zone setting unit, and the dead zone setting unit is used to generate the first power control signal, the second power control signal, the first switch control signal and the second switch control signal with a set dead zone time.

[0027] Optionally, the power module includes a first transistor and a second transistor, the first end of the first transistor is electrically connected to the first end of the second transistor and serves as the input end of the power module, the second end of the first transistor serves as the first output end of the power module, and the control end of the first transistor serves as the first control end of the power module to access the first power control signal; the second end of the second transistor serves as the second output end of the power module, and the control end of the second transistor serves as the second control end of the power module to access the second power control signal.

[0028] Optionally, the magnetic element includes a first inductor and a second inductor, the first end of the first inductor serves as the first end of the magnetic element, the second end of the first inductor is electrically connected to the first end of the second inductor and serves as the third end of the magnetic element, and the second end of the second inductor serves as the second end of the magnetic element.

[0029] Optionally, the first inductor and the second inductor constitute a coupled inductor.

[0030] According to another aspect of the present invention, a power supply assembly is provided, the power supply assembly comprising a DC power supply and the voltage conversion circuit as described above, the DC power supply being electrically connected to a power input terminal of the voltage conversion circuit.

[0031] The technical solution of the embodiment of the present invention adopts a voltage conversion circuit comprising: a power module, a magnetic element, a first gain unit and an output capacitor; the input end of the power module serves as the first power input end of the voltage conversion circuit, the first output end of the power module is electrically connected to the first end of the magnetic element, the second output end of the power module is electrically connected to the second end of the magnetic element, the power module can connect its input end with its first output end based on the control of the first power control signal, and connect its input end with its second output end based on the control of the second power control signal; the third end of the magnetic element serves as the second power input end of the voltage conversion circuit, and the magnetic element can store or release energy; the first gain unit comprises a first charge storage element, the first end of the first charge storage element serves as the first end of the first gain unit and is electrically connected to the second end of the magnetic element, the second end of the first gain unit is electrically connected to the first end of the magnetic element, the third end of the first gain unit is electrically connected to the first end of the output capacitor, the first gain unit can connect the second end of the first charge storage element with the second end of the first gain unit based on the control of the first switch control signal, and connect the second end of the first charge storage element with the third end of the first gain unit based on the control of the second switch control signal; the second end of the output capacitor is electrically connected to the second power input end of the voltage conversion circuit. In one cycle, the portion between the first end and the third end and the portion between the second end and the third end of the magnetic element can be alternately charged and discharged, so that the first charge storage element can store more charge in one cycle, and thus can obtain a higher voltage during discharge, that is, a higher voltage transformation ratio can be achieved by using a lower switching duty cycle.

[0032] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0034] Figure 1 A schematic diagram of a circuit structure of a voltage conversion circuit provided by an embodiment of the present invention;

[0035] Figure 2 A schematic diagram of an application of a voltage conversion circuit provided by an embodiment of the present invention;

[0036] Figure 3A schematic diagram of a circuit structure of another voltage conversion circuit provided by an embodiment of the present invention;

[0037] Figure 4 A schematic diagram of an application of another voltage conversion circuit provided by an embodiment of the present invention;

[0038] Figure 5 A schematic diagram of a circuit structure of another voltage conversion circuit provided by an embodiment of the present invention;

[0039] Figure 6 A schematic diagram of an application of another voltage conversion circuit provided by an embodiment of the present invention;

[0040] Figure 7 A schematic diagram of the circuit structure of a digital hybrid control module provided by an embodiment of the present invention;

[0041] Figure 8 A schematic diagram of the circuit structure of a comparison reference generator provided by an embodiment of the present invention;

[0042] Fig. 9 and Fig.10 A simulation timing diagram of a voltage conversion circuit provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0043] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0044] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0045] Figure 1 A schematic diagram of a circuit structure of a voltage conversion circuit provided by an embodiment of the present invention, Figure 2A schematic diagram of an application of a voltage conversion circuit provided by an embodiment of the present invention, referring to Figure 1 The voltage conversion circuit includes: a power module 101, a magnetic element 102, a first gain unit 103 and an output capacitor Co; the input end of the power module 101 is used as a first power input end Vin1 of the voltage conversion circuit, the first output end of the power module 101 is electrically connected to the first end B of the magnetic element 102, the second output end of the power module 101 is electrically connected to the second end A of the magnetic element 102, and the power module 101 can be based on the first power control signal S M1 The control of the input terminal of the power supply is connected to the first output terminal of the power supply, and based on the second power control signal S M2 The control connects its input end with its second output end; the third end of the magnetic element 102 serves as the second power input end Vin2 of the voltage conversion circuit, and the magnetic element 102 can store or release energy; the first gain unit 103 includes a first charge storage element C11, the first end of the first charge storage element C11 serves as the first end a1 of the first gain unit 103 and is electrically connected to the second end A of the magnetic element 102, the second end b1 of the first gain unit 103 is electrically connected to the first end B of the magnetic element 102, the third end c1 of the first gain unit 103 is electrically connected to the first end of the output capacitor Co, and the first gain unit 103 can be based on the first switch control signal S sub11 The second end of the first charge storage element C11 is connected to the second end of the first gain unit 103 by the control of the second switch control signal S sub12 The second end of the first charge storage element C11 is electrically connected to the third end of the first gain unit 103 under the control of ; the second end of the output capacitor Co is electrically connected to the second power input terminal Vin2 of the voltage conversion circuit.

[0046] Specifically, the two power input terminals of the voltage conversion circuit are used to connect the DC power supply Vin, the first terminal of the output capacitor Co is used as the first power output terminal Vout1 of the voltage conversion circuit, the second terminal of the output capacitor Co is used as the second power output terminal Vout2 of the voltage conversion circuit, and the power output terminal of the voltage conversion circuit is used to connect the subsequent load RL, for example, the subsequent circuit. The voltage conversion circuit can convert the voltage of the DC power supply, for example, boost the voltage and transmit it to the subsequent load. Specifically, the first power control signal, the second power control signal, the first switch control signal and the second switch control signal are all PWM signals. During the operation of the voltage conversion circuit, the input end of the power module 101 and the first output end B are periodically turned on, and the input end of the power module 101 and the second output end A are periodically turned on, and energy is periodically stored between the first end and the third end, and between the second end and the third end of the magnetic element 102; for example, when the input end of the power module 101 and the first output end B are turned on, the first end B of the magnetic element 102 is connected to a DC power supply, so that energy is stored between the first end B and the third end of the magnetic element 102; when the input end of the power module 101 and the second output end are turned on, the second end A of the magnetic element 102 is connected to a DC power supply, so that energy is stored between the second end A and the third end of the magnetic element 102. And because the first gain unit 103 includes a first charge storage element C11, when the second end of the first charge storage element C11 is connected to the third end c1 of the first gain unit 103, the first charge storage element C11 and the magnetic element 102 jointly charge the output capacitor Co, so that the output voltage of the voltage conversion circuit increases; when the second end of the first charge storage element C11 is connected to the second end b1 of the first gain unit 103, the magnetic element can charge the first charge storage element C11. From the above analysis, it can be seen that the first charge storage element C11 is equivalent to being connected in series to the power supply circuit between the magnetic element 102 and the output capacitor Co, and the part between the first end and the third end and the part between the second end and the third end of the magnetic element 102 can be alternately charged and discharged in one cycle, so that the first charge storage element C11 can store more charge in one cycle, and then can obtain a higher voltage when discharging, that is, when the switch duty ratio of each control signal is low, the ratio of the output voltage to the input voltage is still large, that is, a higher voltage conversion ratio can be achieved by using a lower switch duty ratio. In the above embodiment, the output capacitor Co can also play a filtering role to reduce the ripple of the output voltage.

[0047] The technical solution of this embodiment adopts a voltage conversion circuit including: a power module, a magnetic element, a first gain unit and an output capacitor; the input end of the power module serves as the first power input end of the voltage conversion circuit, the first output end of the power module is electrically connected to the first end of the magnetic element, the second output end of the power module is electrically connected to the second end of the magnetic element, the power module can connect its input end with its first output end based on the control of the first power control signal, and connect its input end with its second output end based on the control of the second power control signal; the third end of the magnetic element serves as the second power input end of the voltage conversion circuit, and the magnetic element can store or release energy; the first gain unit includes a first charge storage element, the first end of the first charge storage element serves as the first end of the first gain unit and is electrically connected to the second end of the magnetic element, the second end of the first gain unit is electrically connected to the first end of the magnetic element, the third end of the first gain unit is electrically connected to the first end of the output capacitor, the first gain unit can connect the second end of the first charge storage element with the second end of the first gain unit based on the control of the first switch control signal, and connect the second end of the first charge storage element with the third end of the first gain unit based on the control of the second switch control signal; the second end of the output capacitor is electrically connected to the second power input end of the voltage conversion circuit. In one cycle, the portion between the first end and the third end and the portion between the second end and the third end of the magnetic element can be alternately charged and discharged, so that the first charge storage element can store more charge in one cycle, and thus can obtain a higher voltage during discharge, that is, a higher voltage transformation ratio can be achieved by using a lower switching duty cycle.

[0048] In the above implementation, each module adopts modular design, with fewer components and higher integration, resulting in a smaller volume. At the same time, it has the effect of staggered parallel connection (to be described later) in high-power applications, reduces the current ripple of the voltage conversion circuit, and improves the power quality.

[0049] Optionally, in the above embodiment, the power module 101 includes a first transistor M1 and a second transistor M2, the first end of the first transistor M1 is electrically connected to the first end of the second transistor M2 and serves as the input end of the power module 101, the second end of the first transistor M1 serves as the first output end B of the power module 101, the control end of the first transistor M1 serves as the first control end of the power module 101, and the first control end of the power module 101 is used to access the first power control signal; the second end of the second transistor M2 serves as the second output end A of the power module 101, and the second transistor M2 serves as the second control end of the power module to access the second power control signal. The magnetic element 102 includes a first inductor L1 and a second inductor L2, the first end of the first inductor L1 serves as the first end B of the magnetic element 102, the second end of the first inductor L1 is electrically connected to the first end of the second inductor L2 and serves as the third end of the magnetic element 102, and the second end of the second inductor L2 serves as the second end A of the magnetic element 102. The first gain unit 103 also includes: a first switch element MK1 and a second switch element MK2; the first end of the first switch element MK1 is electrically connected to the second end of the first charge storage element C11, the second end of the first switch element MK1 is electrically connected to the second end of the first gain unit 103, and the control end of the first switch element MK1 is connected to the first switch control signal; the first end of the second switch element MK2 is electrically connected to the second end of the first charge storage element C11, the second end of the second switch element MK2 is electrically connected to the third end c1 of the first gain unit 103, and the control end of the second switch element MK2 is connected to the second switch control signal. The first switch element MK1 and the second switch element MK2 can both be transistors. The transistors in the voltage conversion circuit can all be transistors with an operating frequency range of 0kHz to 300kHz, and the transistors are any one of metal oxide semiconductor field effect transistors, silicon carbide transistors, gallium nitride transistors, high electron mobility transistors, or insulated gate bipolar transistors.

[0050] In the above embodiment, the duty cycle and period of the first power control signal are the same as those of the second power control signal, and the second power control signal is 180 degrees out of phase with the first power control signal; the first switch control signal is inverted to the first power control signal; and the second switch control signal is inverted to the second power control signal. The first charge storage element may be a capacitor. In some embodiments, the first inductor and the second inductor may form a coupled inductor, thereby further improving the power density of the power supply. Of course, the first inductor and the second inductor may also be discrete inductors.

[0051] Specifically, the above configuration allows each transistor to have three combination modes when the duty cycle of the control signal is determined. When the duty cycle is greater than 0.5, it includes mode 1: the second transistor M2 is turned on, the first transistor M1 is turned off, the first switch element MK1 is turned on, and the second switch element MK2 is turned off; at this time, the DC power supply charges the second inductor L2, and the current of the second inductor L2 increases; the DC power supply and the first inductor L1 charge the first charge storage element C11, and the current of the first inductor L1 decreases, and at this time, the output capacitor Co supplies power to the output end of the power supply.

[0052] Mode 2: The first transistor M1 is turned on, the second transistor M2 is turned off, the second switch element MK2 is turned on, and the first switch element MK1 is turned off. At this time, the DC power supply charges the first inductor L1, and the current of the first inductor L1 increases; the second inductor L2 and the first charge storage element C11 charge the output capacitor Co, and the current of the second inductor L2 decreases. The second inductor L2 and the first charge storage element C11 jointly supply power to the output capacitor Co.

[0053] Mode three: the first transistor M1 is turned on, the second transistor M2 is turned on, the first switch element MK1 is turned off, and the second switch element MK2 is turned off; at this time, the DC power supply charges the first inductor L1 and the second inductor L2, and the current of the first inductor L1 and the second inductor L2 increases; the first charge storage element C11 maintains balance, and the terminal voltage remains unchanged. At this time, the output capacitor Co supplies power to the output end of the power supply.

[0054] From the above analysis, it can be known that within one cycle, when one inductor is in a discharging state, the other inductor is in a charging state, and both inductors can release the stored energy to the first charge storage element C11, thereby enabling the first charge storage element C11 to obtain higher energy within one cycle even if the duty cycle is low, and ultimately enabling the power supply output end to output a higher voltage.

[0055] When the duty cycle of the control signal is less than 0.5, it includes the above-mentioned Mode 1 and Mode 2, and also includes Mode 4: the first transistor M1 and the second transistor M2 are turned off, and the first switch element MK1 and the second switch element MK2 are turned on. At this time, the first charge storage element C11 and the second inductor L2 jointly power the output capacitor Co through the second switch element MK2; and the first charge storage element C11 and the first inductor L1 jointly power the output capacitor Co through the first switch element MK1 and the second switch element MK2. It can be seen that when the duty cycle is low, within one cycle, when one inductor is in a discharging state, the other inductor is in a charging state, and both inductors can release the stored energy to the first charge storage element C11, so that the first charge storage element C11 can obtain higher energy within one cycle even if the duty cycle is low, and finally the power supply output end can output a higher voltage.

[0056] In addition, when the duty cycle is equal to 0.5, only the above-mentioned mode 1 and mode 2 are included, and the first charge storage element C11 can still supply power to the output capacitor Co.

[0057] Optionally, Figure 3 A schematic diagram of a circuit structure of another voltage conversion circuit provided by an embodiment of the present invention is shown. Figure 4 A schematic diagram of another voltage conversion circuit provided by an embodiment of the present invention is shown in FIG. Figure 3 and Figure 4 The voltage conversion circuit also includes at least one stage of detachable second gain unit SCU, the second gain unit SCU includes a second charge storage element C01 and a third charge storage element C02, the first end of the second charge storage element C01 serves as the first end a of the second gain unit SCU, the first end of the third charge storage element C02 serves as the third end c of the second gain unit SCU, and the second end of the third charge storage element C02 serves as the fourth end d of the second gain unit SCU; the second gain unit SCU can conduct the second end of the second charge storage element C01 with the second end b of the second gain unit SCU based on the control of the first switch control signal, and conduct the second end of the second charge storage element C01 with the third end c of the second gain unit SCU based on the control of the second switch control signal. When the voltage conversion circuit is configured to be connected to at least one stage of the second gain unit SCU, the second end b1 of the first gain unit 103 is electrically connected to the first end B of the magnetic element 102 through the at least one stage of the second gain unit SCU; wherein the first end a of each stage of the second gain unit SCU is electrically connected to the second end A of the magnetic element 102, the second end b(1) of the first stage of the second gain unit SCU(1) is electrically connected to the first end B of the magnetic element 102, and the fourth end d(1) of the first stage of the second gain unit SCU(1) is electrically connected to the second end b(1) of the first stage of the second gain unit SCU(1); the third end c of the previous stage of the second gain unit SCU is electrically connected to the second end of the next stage of the second gain unit, and the fourth end of the previous stage of the second gain unit is electrically connected to the fourth end of the next stage of the second gain unit, wherein the third end of the last stage of the second gain unit is electrically connected to the second end of the first gain unit, and the fourth end of the last stage of the second gain unit is suspended.

[0058] Specifically, when the voltage conversion circuit only uses the first gain unit, the voltage gain of the first gain unit is limited. Therefore, if the voltage conversion circuit needs to achieve a higher voltage gain, at least one second gain unit SCU can be added. Each additional second gain unit SCU can increase the voltage conversion ratio when the duty cycle of the control signal remains unchanged. The user can add a preset number of second gain units SCU as needed to obtain the required voltage conversion ratio.

[0059] In the above embodiment, the second gain unit further includes a third switch element MK3 and a fourth switch element MK4, the first end of the third switch element MK3 is electrically connected to the second end of the second charge storage element C01, the second end of the third switch element MK3 is electrically connected to the second end of the second gain unit SCU, and the control end of the third switch element MK3 is connected to the first switch control signal; the first end of the fourth switch element MK4 is electrically connected to the second end of the second charge storage element CO1, the second end of the fourth switch element MK4 is electrically connected to the third end of the second gain unit SCU, and the control end of the fourth switch element MK4 is connected to the second switch control signal. The third switch element MK3 and the fourth switch element MK4 can both use transistors, and the second charge storage element C01 and the third charge storage element C02 can both use capacitors.

[0060] Similar to the case where only the first gain unit is included, when at least one level of the second gain unit is used, if the duty cycle of the control signal is greater than 0.5, the combined states of the transistors also include mode 1, mode 2, and mode 3. The states of the first gain unit in each mode are as described above, and only the state of the second gain unit is described below.

[0061] In mode 1, the first transistor M1 is turned off, the second transistor M2 is turned on, the third switch element MK3 is turned on, and the fourth switch element MK4 is turned off. The DC power supply Vin charges the second inductor L2, and the current of the second inductor L2 increases. At this time, the second charge storage element C01 in the first-stage second gain unit SCU is charged by the loop composed of the DC power supply Vin and the first inductor L1; the second charge storage element C01 in other second gain units SCU is charged by the loop composed of the DC power supply Vin, the first inductor L1 and the third charge storage element C02 in the second gain unit SCU of the previous stage, and the current of the first inductor L1 decreases. The output capacitor Co supplies power to the output end of the power supply.

[0062] In mode 2, the first transistor M1 is turned on, the second transistor M2 is turned off, the third switch element MK3 is turned off, and the fourth switch element MK4 is turned on. At this time, the DC power supply Vin charges the first inductor L1, and the current of the first inductor L1 increases; in each second gain unit, the second charge storage element, the third charge storage element and the fourth switch element MK4 form a conduction loop with the second inductor L2 and the DC power supply, so that each third charge storage element is charged by the DC power supply, the second inductor and the corresponding second charge storage element, and the current on the second inductor L2 decreases. At this time, the second inductor L2, each second charge storage element and the output capacitor supply power to the output end of the power supply. In this embodiment, since multiple charge storage elements supply power to the output capacitor together, it is equivalent to a capacitor with a larger capacitance supplying power to the output capacitor, thereby further improving the output voltage value. That is, the voltage conversion ratio can be improved by adding a second gain unit.

[0063] In mode 3, the first transistor M1 is turned on, the second transistor M2 is turned on, and the third switch element MK3 and the fourth switch element MK4 are turned off. The DC power supply Vin supplies power to the first inductor L1 and the second inductor L2, and the current of the first inductor L1 and the second inductor L2 increases. The second charge storage element and the third charge storage element maintain balance, and the terminal voltage remains unchanged. The output capacitor Co supplies power to the output terminal of the power supply.

[0064] If the duty cycle of the control signal is less than 0.5, the combined states of the transistors also include mode 1, mode 2 and mode 4. The states of the voltage conversion circuit in mode 1 and mode 2 are consistent with the above, and will not be repeated here.

[0065] In mode 4, the first transistor M1 and the second transistor M2 are turned off, and the third switch element MK3 and the fourth switch element MK4 are turned on. At this time, the second charge storage element and the third charge storage element both supply power to the output capacitor Co.

[0066] In the above implementation, each gain unit distributes the voltage stress of the power device in the module to the corresponding series capacitor through the module combination, which can effectively reduce the voltage stress of the power switch tube (the first transistor and the second transistor) and improve the reliability of the circuit operation. In addition, the gain units all include high-frequency capacitors, so that the voltage conversion circuit allows high-frequency operation in the MHz range, so that the volume of the magnetic components in the voltage conversion circuit can be greatly reduced, which is conducive to circuit integration and miniaturization.

[0067] Optionally, Figure 5 A schematic diagram of a circuit structure of another voltage conversion circuit provided by an embodiment of the present invention is shown. Figure 6 A schematic diagram of another voltage conversion circuit provided by an embodiment of the present invention is shown in FIG. Figure 5 and Figure 6 The voltage conversion circuit further includes a digital hybrid control module 104, which is electrically connected to the output end of the voltage conversion circuit and is used to adjust the first power control signal, the second power control signal, the first switch control signal and the second switch control signal according to the output voltage of the voltage conversion circuit.

[0068] Specifically, when the voltage conversion circuit is in use, its output voltage may be unstable. In this embodiment, the digital hybrid control module 104 can feedback and adjust various control signals so that the output voltage can be in a stable state.

[0069] For example, Figure 7 As shown, Figure 7A schematic diagram of the circuit structure of a digital hybrid control module provided in an embodiment of the present invention. The digital hybrid control module 104 includes: a threshold comparison unit 1041, a transient mode compensation control unit 1042, a control mode selection unit 1043 and a steady-state PID compensation control unit 1044; the threshold comparison unit 1041 is electrically connected to the output end of the voltage conversion circuit, and the threshold comparison unit 1041 is used to generate a comparison signal according to the output voltage of the voltage conversion circuit; the transient mode compensation control unit 1042 is electrically connected to the threshold comparison unit 1041, and is used to generate a selection signal Sel and a transient control signal I1 according to the comparison signal, and the transient control signal is used to generate a duty cycle not higher than a preset The upper limit or the first power control signal, the second power control signal, the first switch control signal and the second switch control signal are not lower than the preset lower limit; the steady-state PID compensation control unit 1044 is electrically connected to the control mode selection unit 1043, and the steady-state PID compensation control unit 1044 is used to generate a steady-state adjustment signal I2 according to the output voltage, and the steady-state adjustment signal is used to generate a steady-state first power control signal, a second power control signal, a first switch control signal and a second switch control signal; the control mode selection unit 1043 is used to output a transient control signal or a steady-state adjustment signal according to the selection signal.

[0070] Specifically, the digital hybrid control module has steady-state control, that is, when the load corresponding to the voltage conversion circuit is stable, the voltage conversion circuit is controlled to operate stably, and the steady-state control can be achieved by the steady-state PID compensation control unit 1044. The steady-state PID compensation control unit 1044 may include an adder 201, a PID regulator 202, a limiter structure 203 and a PWM generator 204. The sampled voltage V of the output voltage of the voltage conversion circuit o_sense and the output voltage reference error V o_ref After passing through the adder 201, the PID regulator 202 performs PID regulation to obtain a steady-state regulation signal. The regulation signal is limited by the limiting structure 203 and then output to the PWM generator 204. The PWM generator 204 generates a steady-state control signal.

[0071] In addition, the digital hybrid control module can also realize the transient control mode, that is, when the load of the voltage conversion circuit changes greatly, its output voltage also changes greatly, and the power supply is greatly affected when the output voltage changes greatly. Therefore, transient control can be realized by the transient mode compensation unit. Specifically, the threshold comparison unit 1041 first generates an over-threshold signal according to the output voltage, and the over-threshold signal contains the over-threshold information at the moment of load switching, and the over-threshold information may be higher than the set threshold, or lower than the set threshold. Then the steady-state mode compensation control unit 1042 generates a transient control signal according to the over-threshold information. For example, when the load becomes larger instantly, in order to maintain the output voltage unchanged, the duty cycle of the control signal will be adjusted greatly at this time, and the duty cycle that increases instantly will cause the operation of each transistor to be greatly affected, so the transient mode compensation control unit can generate a transient control signal at this time to control the duty cycle upper limit of each control signal to avoid the duty cycle of each control signal becoming too large instantly. When the load becomes smaller instantly, in order to maintain the output voltage unchanged, the duty cycle of the control signal will be adjusted to be very small. The instantaneous decrease in duty cycle will also have a significant impact on the operation of each transistor. Therefore, the transient mode compensation control unit can generate a transient control signal at this time to control the lower limit of the duty cycle of each control signal to prevent the duty cycle of each control signal from becoming too small instantly. In other words, the transient control signal can minimize the output voltage deviation and / or recovery time of the voltage conversion circuit at the moment of load switching, that is, to generate the minimum voltage deviation value or the optimal response of the output voltage time. Prevent load switching from having a significant impact on the voltage conversion circuit and ensure the reliability of the operation of the voltage conversion circuit.

[0072] From the above analysis, it can be seen that the digital hybrid control module can realize closed-loop control of the voltage conversion circuit, and the spacing adapts to the steady-state and transient working modes of the voltage conversion circuit. It can effectively allocate the on-time between each transistor phase and realize fast and smooth transient recovery of the voltage conversion circuit.

[0073] When the threshold comparison unit 1041 generates an over-threshold comparison signal (for example, the comparison result is 1), the transient mode compensation control unit 1042 generates a transient control signal on the one hand, and generates a selection signal on the other hand so that the control mode selection unit 1043 outputs the transient control signal to the subsequent stage. When the threshold comparison unit 1041 does not generate an over-threshold comparison signal (for example, the comparison result is 0), the transient mode compensation control unit generates a selection signal so that the control mode selection unit 1043 outputs the steady-state adjustment signal to the subsequent stage.

[0074] Figure 8 A schematic diagram of a circuit structure of a comparison reference generator provided by an embodiment of the present invention, referring to Figure 7 and Figure 8. The threshold comparison unit 1041 includes a comparison reference generator 301, a first comparator COMP1 and a second comparator COMP2; the comparison reference generator 301 includes two first resistors R1, two second resistors R2, a third resistor R3, a third comparator COMPL and a fourth comparator COMPH. The first end of the first first resistor R1 is connected to the output voltage, the second end of the first first resistor R1 is electrically connected to the first end of the third resistor R3, the second end of the third resistor R1 is electrically connected to the first end of the first second resistor R2, and the second end of the first second resistor R2 is grounded. The first end of the second first resistor R1 is connected to the output voltage, the second end of the second first resistor R1 is electrically connected to the first end of the second second resistor R2, and the second end of the second second resistor R2 is grounded. The non-inverting input terminal of the third comparator COMPL is electrically connected to the first end of the first second resistor R2, and the inverting input terminal of the third comparator COMPL is electrically connected to the first end of the second second resistor R2; the inverting input terminal of the fourth comparator COMPL is electrically connected to the second end of the first first resistor R1, and the non-inverting input terminal of the fourth comparator COMPL is electrically connected to the first end of the second second resistor R2. The output terminal of the third comparator COMPL is electrically connected to the inverting input terminal of the first comparator COMP1, and the non-inverting input terminal of the first comparator COMP1 is connected to the first reference voltage V o_f The positive input terminal of the second comparator COMP2 is connected to the first reference voltage V o_f The inverting input terminal of the second comparator COMP2 is electrically connected to the output terminal of the fourth comparator COMPL. The third comparator COMPL is used to generate a low comparison threshold value V th_H The fourth comparator COMPH is used to generate a high comparison threshold V th_L After the output voltage is divided by each resistor, different voltage comparisons are obtained according to different voltage division ratios, and then sent to the third comparator and the fourth comparator to obtain the low comparison threshold V th_H and high comparison threshold V th_L Finally, the comparison result required by the transient mode compensation control unit 1042 is generated by the first comparator and the second comparator.

[0075] It should be noted that the threshold design value output by the comparison reference generator needs to take into account the accuracy of transient detection and operation as well as preventing false triggering of the transient mode compensation control unit. Therefore, the design value needs to be specifically designed according to the fluctuation of the output voltage.

[0076] Optionally, continue to refer to Figure 7The digital hybrid control module further includes a dead zone setting unit 1045, the output end of the control mode selection unit is electrically connected to the dead zone setting unit, and the dead zone setting unit 1045 is used to generate a first power control signal, a second power control signal, a first switch control signal and a second switch control signal with a set dead time. The dead zone setting unit 1045 can insert a set dead time between the complementary control signals of the turned-on transistors to prevent any two complementary turned-on transistors from being directly turned on.

[0077] For example, Fig. 9 and Fig.10 A simulation timing diagram of a voltage conversion circuit provided by an embodiment of the present invention, referring to Fig. 9 and Fig.10 When the voltage conversion circuit includes two-stage second gain units, when the input voltage is 100V, the output voltage can reach 1000V, which has a very high voltage gain. In addition, it can be seen from the waveform that the current I L1 And the second inductor I L2 The ripple frequency is twice the frequency of the control signal of each transistor, and the current I L1 And the second inductor I L2 The circuits are staggered in parallel, thus effectively reducing the input current ripple.

[0078] The embodiment of the present invention further provides a power supply assembly, which includes a DC power supply and a voltage conversion circuit provided in any embodiment of the present invention, and the DC power supply is electrically connected to a power input terminal of the voltage conversion circuit. Since it includes the voltage conversion circuit provided in any embodiment of the present invention, it also has the same beneficial effects, which will not be described in detail here.

[0079] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the present invention can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solution of the present invention can be achieved, and this document does not limit this.

[0080] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A voltage conversion circuit, characterized in that: The voltage conversion circuit includes: a power module, a magnetic element, a first gain unit and an output capacitor; The input end of the power module serves as the first power input end of the voltage conversion circuit, the first output end of the power module is electrically connected to the first end of the magnetic element, the second output end of the power module is electrically connected to the second end of the magnetic element, and the power module can be controlled to conduct its input end with its first output end based on a first power control signal, and to conduct its input end with its second output end based on a second power control signal; The third end of the magnetic element serves as the second power input end of the voltage conversion circuit, and the magnetic element can store or release energy; The first gain unit includes a first charge storage element, a first end of the first charge storage element serves as a first end of the first gain unit and is electrically connected to a second end of the magnetic element, a second end of the first gain unit is electrically connected to a first end of the magnetic element, a third end of the first gain unit is electrically connected to a first end of the output capacitor, and the first gain unit is capable of conducting the second end of the first charge storage element with the second end of the first gain unit based on a control of a first switch control signal, and conducting the second end of the first charge storage element with the third end of the first gain unit based on a control of a second switch control signal; The second end of the output capacitor is electrically connected to the second power input end of the voltage conversion circuit.

2. The voltage conversion circuit according to claim 1, characterized in that: The first gain unit further includes: a first switch element and a second switch element; The first end of the first switch element is electrically connected to the second end of the first charge storage element, the second end of the first switch element is electrically connected to the second end of the first gain unit, and the control end of the first switch element is connected to the first switch control signal; The first end of the second switch element is electrically connected to the second end of the first charge storage element, the second end of the second switch element is electrically connected to the third end of the first gain unit, and the control end of the second switch element is connected to the second switch control signal.

3. The voltage conversion circuit according to claim 1, characterized in that: The first power control signal has the same duty cycle and period as the second power control signal, and the second power control signal is 180 degrees out of phase with the first power control signal; The first switch control signal is inverted to the first power control signal; the second switch control signal is inverted to the second power control signal.

4. The voltage conversion circuit according to claim 1, characterized in that: The voltage conversion circuit also includes at least one stage of detachable second gain unit, the second gain unit includes a second charge storage element and a third charge storage element, the first end of the second charge storage element serves as the first end of the second gain unit, the first end of the third charge storage element serves as the third end of the second gain unit, and the second end of the third charge storage element serves as the fourth end of the second gain unit; the second gain unit is capable of conducting the second end of the second charge storage element with the second end of the second gain unit based on the control of the first switch control signal, and conducting the second end of the second charge storage element with the third end of the second gain unit based on the control of the second switch control signal; When the voltage conversion circuit is configured to be connected to at least one stage of the second gain unit, the second end of the first gain unit is electrically connected to the first end of the magnetic element through the at least one stage of the second gain unit; wherein the first end of each stage of the second gain unit is electrically connected to the second end of the magnetic element, the second end of the first stage of the second gain unit is electrically connected to the first end of the magnetic element, and the fourth end of the first stage of the second gain unit is electrically connected to the second end of the first stage of the second gain unit; The third end of the second gain unit is electrically connected to the second end of the second gain unit of the next stage, and the fourth end of the second gain unit is electrically connected to the fourth end of the second gain unit of the next stage, wherein the third end of the second gain unit of the last stage is electrically connected to the second end of the first gain unit, and the fourth end of the second gain unit of the last stage is suspended.

5. The voltage conversion circuit according to claim 4, characterized in that: The second gain unit further includes a third switch element and a fourth switch element, the first end of the third switch element is electrically connected to the second end of the second charge storage element, the second end of the third switch element is electrically connected to the second end of the second gain unit, and the control end of the third switch element is connected to the first switch control signal; The first end of the fourth switch element is electrically connected to the second end of the second charge storage element, the second end of the fourth switch element is electrically connected to the third end of the second gain unit, and the control end of the fourth switch element is connected to the second switch control signal.

6. The voltage conversion circuit according to claim 1 or 4, characterized in that: The voltage conversion circuit also includes a digital hybrid control module, which is electrically connected to the output end of the voltage conversion circuit, and is used to generate the first power control signal, the second power control signal, the first switch control signal and the second switch control signal according to the output voltage of the voltage conversion circuit.

7. The voltage conversion circuit according to claim 6, characterized in that: The digital hybrid control module comprises: A threshold comparison unit, a transient mode compensation control unit, a control mode selection unit, and a steady-state PID compensation control unit; The threshold comparison unit is electrically connected to the output end of the voltage conversion circuit, and the threshold comparison unit is used to generate a comparison signal according to the output voltage of the voltage conversion circuit; the transient mode compensation control unit is electrically connected to the threshold comparison unit, and is used to generate a selection signal and a transient control signal according to the comparison signal, and the transient control signal is used to generate the first power control signal, the second power control signal, the first switch control signal, and the second switch control signal whose duty ratio is not higher than a preset upper limit or not lower than a preset lower limit; The steady-state PID compensation control unit is electrically connected to the control mode selection unit, and the steady-state PID compensation control unit is used to generate a steady-state adjustment signal according to the output voltage, and the steady-state adjustment signal is used to generate the first steady-state power control signal, the second power control signal, the first switch control signal, and the second switch control signal; The control mode selection unit is used to output the transient control signal or the steady-state regulation signal according to the selection signal.

8. The voltage conversion circuit according to claim 7, characterized in that: The digital hybrid control module also includes a dead zone setting unit, and the output end of the control mode selection unit is electrically connected to the dead zone setting unit, and the dead zone setting unit is used to generate the first power control signal, the second power control signal, the first switch control signal and the second switch control signal with a set dead zone time.

9. The voltage conversion circuit according to claim 1, characterized in that: The power module includes a first transistor and a second transistor, wherein the first end of the first transistor is electrically connected to the first end of the second transistor and serves as the input end of the power module, the second end of the first transistor serves as the first output end of the power module, and the control end of the first transistor serves as the first control end of the power module to access the first power control signal; the second end of the second transistor serves as the second output end of the power module, and the control end of the second transistor serves as the second control end of the power module to access the second power control signal.

10. The voltage conversion circuit according to claim 1, characterized in that: The magnetic element includes a first inductor and a second inductor, the first end of the first inductor serves as the first end of the magnetic element, the second end of the first inductor is electrically connected to the first end of the second inductor and serves as the third end of the magnetic element, and the second end of the second inductor serves as the second end of the magnetic element.

11. The voltage conversion circuit according to claim 10, characterized in that: The first inductor and the second inductor form a coupled inductor.

12. A power supply assembly, characterized in that: The power supply component includes a DC power supply and a voltage conversion circuit according to any one of claims 1 to 11, and the DC power supply is electrically connected to a power input terminal of the voltage conversion circuit.

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