Driving power supply circuit based on transformer

Abstract

The invention provides a driving power supply circuit based on a transformer. The driving power supply circuit can be applied to the technical field of circuit design. The circuit comprises a conversion module which comprises a transformer and a resonance unit connected with the primary side of the transformer, the resonance unit is connected to a driving power supply module, and the conversion module is used for converting received alternating voltage and alternating current into target voltage and target current respectively; the driving power supply module comprises a filter capacitor and a plurality of driving switches, and the driving power supply module is configured to switch the respective conduction states of the plurality of driving switches according to the current driving voltage of the filter capacitor and the target driving voltage required by the circuit, and dynamically adjust the resonant current generated by the resonant unit as the charging duration of the filter capacitor; the voltage of the filter capacitor is stabilized at the target driving voltage, and the time sequence of the target driving voltage is synchronous with the phase of the resonance current.

Description

Technical Field

[0001] The present disclosure relates to the technical field of circuit design, and more particularly, to a transformer-based drive power supply circuit. Background Art

[0002] Transformer-based full-bridge DC-to-DC converters (DC-DC converters) are commonly used in high-voltage, high-conversion-ratio, and high-current applications. However, in high-current applications, the large size of the power transistors also leads to high power consumption in the gate driver.

[0003] In the process of realizing the concept of the present disclosure, the inventors discovered that the converter driving power supply in the related art has at least a technical problem of low efficiency or low power density. Summary of the Invention

[0004] In view of this, the present disclosure provides a transformer-based converter circuit.

[0005] One aspect of the present disclosure provides a transformer-based converter circuit, comprising:

[0006] A conversion module includes a transformer and a resonant unit connected to the primary side of the transformer, wherein the resonant unit is connected to a driving power supply module, and the conversion module is used to convert the received AC voltage and AC current into a target voltage and target current respectively; a driving power supply module includes a filter capacitor and multiple driving switches, and the driving power supply module is configured to switch the respective conduction states of the multiple driving switches according to the current driving voltage of the filter capacitor and the target driving voltage required by the circuit, and dynamically adjust the resonant current generated by the resonant unit to the charging time of the filter capacitor, ensuring that the voltage of the filter capacitor is stable at the target driving voltage, and that the timing of the target driving voltage is synchronized with the phase of the resonant current.

[0007] According to an embodiment of the present disclosure, the driving power supply module is also used to generate an error signal based on the current driving voltage and the target driving voltage required by the circuit; using the error signal, the duty cycle of each of the multiple phases in a single working cycle is adjusted to adjust the resonant current generated by the resonant unit to the charging time of the filter capacitor, thereby stabilizing the voltage of the filter capacitor at the target driving voltage.

[0008] According to an embodiment of the present disclosure, the multiple phases include a charging phase, the error signal includes a first error signal and a second error signal, and the driving power supply module generates a first error signal in response to the current driving voltage being less than the target driving voltage; using the first error signal, the duty cycle of the charging phase is increased, the charging time of the filter capacitor is increased, and the current driving voltage is increased to the target driving voltage.

[0009] According to an embodiment of the present disclosure, the driving power supply module generates a second error signal in response to the current driving voltage being greater than the target driving voltage; the second error signal is used to reduce the duty cycle of the charging phase, shorten the charging time of the filter capacitor, and reduce the current driving voltage to the target driving voltage.

[0010] According to an embodiment of the present disclosure, the circuit also includes an inverter module, which includes a first diagonal switch unit and a second diagonal switch unit. The first diagonal switch unit and the second diagonal switch unit each include multiple power switches. The target driving voltage provides a gate control signal for the multiple power switches. The inverter module is configured to control the first diagonal switch unit and the second diagonal switch unit to alternately conduct according to the respective duty cycles of the multiple phases to invert the DC voltage into AC voltage and AC current, and drive the resonant unit to generate a periodic resonant current.

[0011] According to an embodiment of the present disclosure, the first diagonal switch unit includes a first power switch and a fourth power switch, the second diagonal switch unit includes a second power switch and a third power switch, the first end of the first power switch, the first end of the second power switch and the resonant unit are commonly connected to the first node, and the first end of the third power switch, the first end of the fourth power switch and the resonant unit are commonly connected to the second node.

[0012] According to an embodiment of the present disclosure, the plurality of drive switches include a first drive switch, a second drive switch and a third drive switch, the first end of the first drive switch is connected to the inverter module, the second end of the first drive switch, the first end of the third drive switch and the first end of the second drive switch are commonly connected to the third node, the second end of the second drive switch is connected to the second node, the second end of the third drive switch is connected to the first plate of the filter capacitor, and the second plate of the filter capacitor is grounded.

[0013] According to an embodiment of the present disclosure, the working cycle includes a first sub-cycle and a second sub-cycle. The multiple phases within the first sub-cycle include a first initial phase. In the first initial phase, the resonant current charges the second node and the second node simultaneously until the body diode conduction threshold voltage of the third drive switch is reached, ensuring that the third drive switch is turned on in zero voltage mode, triggering the charging phase.

[0014] According to an embodiment of the present disclosure, the multiple phases within the second sub-period include a second initial phase. In the second initial phase, the resonant current charges the first node and the third node simultaneously until the body diode conduction threshold voltage of the third drive switch is reached, ensuring that the third drive switch is turned on in zero voltage mode, triggering the charging phase.

[0015] According to an embodiment of the present disclosure, the circuit further includes a rectifier module connected to the secondary side of the transformer, the rectifier module includes a plurality of load switches, and the target drive voltage is used to power gate drivers of the plurality of load switches.

[0016] According to the embodiments of the present disclosure, the driving power supply module can charge the filter capacitor according to the resonant current generated by the resonant unit of the primary side of the transformer by adjusting the conduction timing of multiple driving switches, and stabilize the voltage of the filter capacitor at the target driving voltage required by the circuit by dynamically adjusting the current driving voltage of the filter capacitor, thereby ensuring the stable operation of the circuit. Therefore, a stable driving voltage supply can be achieved without adding additional passive components, reducing additional energy consumption and improving power density. At the same time, the timing of the target driving voltage is synchronized with the phase of the resonant current, so that the power tube including the multiple driving switches can operate in a soft switching mode, thereby improving the overall efficiency of the circuit and allowing the power tube to perform switching actions at the moment when the voltage or current passes through zero. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The above and other objects, features and advantages of the present disclosure will become more apparent through the following description of the embodiments of the present disclosure with reference to the accompanying drawings, in which:

[0018] Figure 1 The figure schematically shows a structure diagram of a transformer-based driving power supply circuit according to an embodiment of the present disclosure.

[0019] Figure 2 The figure schematically shows a circuit diagram of a transformer-based driving power supply circuit according to an embodiment of the present disclosure.

[0020] Figure 3A Schematically shows Figure 2 Equivalent circuit diagram of the circuit shown in the first phase.

[0021] Figure 3B Schematically shows Figure 2 Equivalent circuit diagram of the circuit shown in the first initial phase.

[0022] Figure 3C Schematically shows Figure 2 Equivalent circuit diagram of the circuit shown in the charging phase.

[0023] Figure 3D Schematically shows Figure 2 Equivalent circuit diagram of the circuit shown in the second phase.

[0024] Figure 4A Schematically shows Figure 2 Equivalent circuit diagram of the circuit shown in the third phase.

[0025] Figure 4B Schematically shows Figure 2 Equivalent circuit diagram of the circuit shown in the second initial phase.

[0026] Figure 4C Schematically shows Figure 2 Equivalent circuit diagram of the circuit shown in the second charging phase.

[0027] Figure 4D Schematically shows Figure 2 Equivalent circuit diagram of the circuit shown in the fourth phase.

[0028] Figure 5 Schematically shows Figure 2 Waveform diagram of the circuit shown. DETAILED DESCRIPTION

[0029] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are merely exemplary and are not intended to limit the scope of the present disclosure. In the detailed description below, for ease of explanation, many specific details are set forth to provide a comprehensive understanding of the embodiments of the present disclosure. However, it is apparent that one or more embodiments may also be implemented without these specific details. In addition, in the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessary confusion of the concepts of the present disclosure.

[0030] The terms used herein are only for describing specific embodiments and are not intended to limit the present disclosure. The terms "comprise," "include," etc. used herein indicate the presence of the features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0031] All terms used herein (including technical and scientific terms) have the meanings commonly understood by those skilled in the art unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning consistent with the context of this specification and should not be interpreted in an idealized or overly rigid manner.

[0032] When expressions such as "at least one of A, B, and C, etc." are used, they should generally be interpreted in accordance with the meaning commonly understood by those skilled in the art (for example, "a system having at least one of A, B, and C" should include but is not limited to a system having A alone, B alone, C alone, A and B, A and C, B and C, and / or A, B, C, etc.).

[0033] In the process of implementing the inventive concept of the present disclosure, the inventors discovered that:

[0034] For the low-dropout regulator (LDO) drive power supply solution, the power transistor in the LDO generates a lot of heat, so a large chip area is required for heat dissipation. In addition, the drive efficiency is only 10%. For example, when the input voltage is 48V, the drive voltage is only 5V, which means that the power loss is relatively large.

[0035] For the driving and power supply scheme of the DC-DC converter, due to the presence of power tubes operating in hard switching mode, the overlap loss is high, which limits the conversion efficiency of the converter, and the large-sized off-chip inductor will also affect the power density of the converter.

[0036] The drive power supply solution of adding an auxiliary winding to the transformer increases the design difficulty and size of the transformer to a certain extent, affecting the power density of the converter.

[0037] Therefore, the driving and power supply methods adopted by transformer-based converter circuits in related technologies all have the problems of low converter efficiency and low power density.

[0038] In view of this, an embodiment of the present disclosure provides a transformer-based converter circuit, including: a conversion module, including a transformer and a resonant unit connected to the primary side of the transformer, wherein the resonant unit is connected to a driving power supply module, and the conversion module is used to convert the received AC voltage and AC current into a target voltage and target current, respectively; a driving power supply module, including a filter capacitor and multiple driving switches, and the driving power supply module is configured to switch the respective conduction states of the multiple driving switches according to the current driving voltage of the filter capacitor and the target driving voltage required by the circuit, and dynamically adjust the resonant current generated by the resonant unit to the charging time of the filter capacitor, to ensure that the voltage of the filter capacitor is stable at the target driving voltage, and the timing of the target driving voltage is synchronized with the phase of the resonant current.

[0039] Figure 1 The figure schematically shows a circuit structure diagram of a transformer-based converter according to an embodiment of the present disclosure.

[0040] like Figure 1 As shown, the circuit includes a conversion module 110 and a driving power supply module 120. The conversion module 110 includes a transformer 112 and a resonance unit 111 connected to the primary side of the transformer 112. The resonance unit 111 includes a resonant capacitor C r and resonant inductor I r The resonance unit 111 is connected to the driving power supply module 120, which includes a filter capacitor C PVDD and multiple drive switches S c .

[0041] According to an embodiment of the present disclosure, the conversion module 110 is used to convert the received AC voltage V1 and AC current I1 into the target voltage V0 and target current I0 respectively, wherein the conversion ratio depends on the ratio N:1:1 of the number of turns of the primary coil and the secondary coil of the transformer.

[0042] According to an embodiment of the present disclosure, the driving power supply module 120 is driven by the filter capacitor C PVDD The current driving voltage PVDD' and the target driving voltage PVDD required by the circuit are switched to a plurality of driving switches S c The conduction state of each is dynamically adjusted to adjust the resonant current I generated by the resonant unit 111 Lr is the filter capacitor C PVDD The charging time of the filter capacitor C PVDD The voltage is stabilized at the target driving voltage PVDD.

[0043] According to an embodiment of the present disclosure, the target driving voltage PVDD may also be used to power other loads in the circuit.

[0044] According to an embodiment of the present disclosure, the timing of the target driving voltage PVDD and the resonant current I Lr Phase synchronization can avoid the extra losses caused by hard switching, allowing the circuit to operate in soft switching mode. In soft switching mode, the rate of change of current and voltage in the circuit is relatively gentle, reducing the generation of high-frequency harmonics and thus reducing electromagnetic interference.

[0045] Figure 1 This is only an equivalent schematic diagram of the circuit provided in the embodiment of the present disclosure, and does not show the specific device composition. In actual application, the specific topology of the circuit can be determined based on the conversion ratio, power switch withstand voltage, etc.

[0046] According to the embodiments of the present disclosure, the driving power supply module can charge the filter capacitor according to the resonant current generated by the resonant unit of the primary side of the transformer by adjusting the conduction timing of multiple driving switches, and stabilize the voltage of the filter capacitor at the target driving voltage required by the circuit by dynamically adjusting the current driving voltage of the filter capacitor, thereby ensuring the stable operation of the circuit. Therefore, a stable driving voltage supply can be achieved without adding additional passive components, reducing additional energy consumption and improving power density. At the same time, the timing of the target driving voltage is synchronized with the phase of the resonant current, so that the power tube including the multiple driving switches can operate in a soft switching mode, thereby improving the overall efficiency of the circuit and allowing the power tube to perform switching actions at the moment when the voltage or current passes through zero.

[0047] According to an embodiment of the present disclosure, the driving power supply module is also used to generate an error signal based on the current driving voltage and the target driving voltage required by the circuit; using the error signal, the duty cycle of each of the multiple phases in a single working cycle is adjusted to adjust the resonant current generated by the resonant unit to the charging time of the filter capacitor, thereby stabilizing the voltage of the filter capacitor at the target driving voltage.

[0048] According to an embodiment of the present disclosure, the driving power supply module may further include a control unit for monitoring the current driving voltage in real time, and comparing and calculating the current driving voltage and the target driving voltage to generate an error signal, so that the difference between the current driving voltage and the target driving voltage can be reflected by the size and polarity of the error signal.

[0049] According to an embodiment of the present disclosure, the control unit may adjust the duty cycle of each of the multiple phases within a single working cycle using an error signal based on a proportional-integral-derivative control algorithm (PID control algorithm).

[0050] According to an embodiment of the present disclosure, the driving power supply module generates a first error signal in response to the current driving voltage being less than the target driving voltage; the first error signal is used to increase the duty cycle of the charging phase, increase the charging time of the filter capacitor, and increase the current driving voltage to the target driving voltage.

[0051] According to an embodiment of the present disclosure, the driving power supply module generates a second error signal in response to the current driving voltage being greater than the target driving voltage; the second error signal is used to reduce the duty cycle of the charging phase, shorten the charging time of the filter capacitor, and reduce the current driving voltage to the target driving voltage.

[0052] According to an embodiment of the present disclosure, the multiple phases include a charging phase, and the error signal includes a first error signal and a second error signal. The first error signal is used to indicate that the current driving voltage is higher than the target driving voltage, and the second error signal is used to indicate that the current driving voltage is lower than the target driving voltage.

[0053] According to an embodiment of the present disclosure, when the current driving voltage is lower than the target driving voltage, within a single working cycle, the conduction time of the driving switch corresponding to the charging phase increases, and the charging time of the filter capacitor also increases accordingly. The filter capacitor continuously accumulates charge, and the voltage across both ends gradually increases until the current driving voltage is stably increased to the target driving voltage.

[0054] For example, if the target driving voltage required by the circuit is 20V and the current driving voltage is 16V, since 16V<20V, the conduction time of the driving switch corresponding to the charging phase can be increased in the next working cycle until the current driving voltage is increased from 16V to 20V.

[0055] According to an embodiment of the present disclosure, when the current driving voltage is lower than the target driving voltage, within a single working cycle, the conduction time of the driving switch corresponding to the charging phase is shortened, and the charging time of the filter capacitor is also reduced accordingly. The charge accumulated in the filter capacitor is reduced, and the voltage across both ends gradually decreases until the current driving voltage is stably reduced to the target driving voltage.

[0056] For example, if the target driving voltage required by the circuit is 20V and the current driving voltage is 26V, since 26V>20V, the conduction time of the driving switch corresponding to the charging phase can be shortened in the next working cycle until the current driving voltage is reduced from 26V to 20V.

[0057] According to an embodiment of the present disclosure, the driving power supply module generates an error signal by comparing the current driving voltage and the target driving voltage, thereby reducing the duty cycle of the charging phase when the current driving voltage is greater than the target driving voltage, reducing the charging time of the filter capacitor, and reducing the current driving voltage to the target driving voltage. Conversely, when the current driving voltage is less than the target driving voltage, the duty cycle of the charging phase is increased, the charging time of the filter capacitor is increased, and the current driving voltage is increased to the target driving voltage. Therefore, the error signal is used to adjust the duty cycle of each phase. Compared with the related technology, there is no need to add a large number of additional voltage regulating elements or complex control circuits, which can not only achieve high-precision driving voltage regulation, but also improve the reliability and stability of the circuit while simplifying the circuit structure.

[0058] According to an embodiment of the present disclosure, the circuit also includes an inverter module, which includes a first diagonal switch unit and a second diagonal switch unit. The first diagonal switch unit and the second diagonal switch unit each include multiple power switches. The target driving voltage provides a gate control signal for the multiple power switches. The inverter module is configured to control the first diagonal switch unit and the second diagonal switch unit to alternately conduct according to the respective duty cycles of the multiple phases to invert the DC voltage into AC voltage and AC current, and drive the resonant unit to generate a periodic resonant current.

[0059] According to an embodiment of the present disclosure, the power switch may be a metal-oxide semiconductor field-effect transistor (MOSFET) or an insulated gate bipolar transistor (IGBT). Taking a MOSFET as an example, when a target drive voltage is applied to its gate, the on and off states of the MOSFET can be controlled by changing the voltage difference between the gate and the source, thereby ensuring the normal operation of the inverter module.

[0060] According to an embodiment of the present disclosure, the circuit further includes a rectifier module connected to the secondary side of the transformer, the rectifier module includes a plurality of load switches, and the target drive voltage is used to power gate drivers of the plurality of load switches.

[0061] According to an embodiment of the present disclosure, the load switch includes a first load switch and a second load switch, which are respectively connected to the two secondary coils of the transformer. The rectifier module can rectify the low-voltage AC voltage signal obtained in the conversion module into a DC voltage signal.

[0062] According to an embodiment of the present disclosure, the target driving voltage can power not only the load switch, the driving switch, and the power switch in the circuit, but also any load in the circuit.

[0063] To better understand the transformer-based converter circuit of the embodiment of the present disclosure, the following will be Figure 2 The specific connection relationship of the circuit is described.

[0064] Figure 2 A circuit diagram of a transformer-based converter circuit according to an embodiment of the present disclosure is schematically shown.

[0065] It should be noted that Figure 2 The number of switches, capacitors, and inductors is only for illustration and is not limited here.

[0066] like Figure 2 As shown, the converter circuit includes a conversion module 110 , a drive power supply module 120 , an inverter module 210 and a rectifier module 220 .

[0067] According to an embodiment of the present disclosure, for the inverter module 210, the first diagonal switch unit includes a first power switch S P1 and the fourth power switch S P4 The second diagonal switch unit includes a second power switch S P2 and the third power switch S P3 , the first power switch S P1 The first end of the second power switch S P2 The first end and the resonance unit are connected to the first node V P1 , the third power switch S P3 The first end of the fourth power switch S P4 The first end and the resonance unit are connected to the second node V P2 .

[0068] According to an embodiment of the present disclosure, for the driving power supply module 120, the plurality of driving switches include a first driving switch S C1 , the second drive switch S C2 and the third drive switch S C3 , the first drive switch S C1 The first end of the first drive switch S is connected to the inverter module 210. C1 The second end of the third drive switch S C3The first end and the second drive switch S C2 The first ends of the two terminals are connected to the third node V PP , the second drive switch S C2 The second end is connected to the second node V P2 , the third drive switch S C3 The second end is connected to the filter capacitor C PVDD The first plate of the filter capacitor C PVDD The second plate is grounded.

[0069] According to an embodiment of the present disclosure, for the conversion module 110, the primary side of the transformer further includes an excitation inductor L connected in parallel at both ends of the primary winding of the transformer. m , resonant capacitor C r One end is connected to node V P1 , the other end is connected to the resonant inductor L r .

[0070] According to an embodiment of the present disclosure, for the rectifier module 220, the first end of the first load switch S1 is connected to the secondary winding of the transformer, and the other end is grounded; the first end of the second load switch S2 is connected to the other secondary winding of the transformer, and the other end is connected to the load capacitor C O , load capacitance C O A load resistor R can also be connected in parallel O .

[0071] According to an embodiment of the present disclosure, the first and second ends of the plurality of drive switches, load switches, and power switches may represent the source or drain of the switch tube, which is not limited here.

[0072] According to an embodiment of the present disclosure, the working cycle includes a first sub-cycle and a second sub-cycle. The multiple phases within the first sub-cycle include a first initial phase. In the first initial phase, the resonant current charges the second node and the third node simultaneously until the body diode conduction threshold voltage of the third drive switch is reached, ensuring that the third drive switch is turned on in zero voltage mode, triggering the charging phase.

[0073] According to an embodiment of the present disclosure, the first sub-cycle and the second sub-cycle may each be half a cycle, the charging phase may include a first charging phase and a second charging phase, and the first sub-cycle may sequentially include a first phase, a first initial phase, a first charging phase, and a second phase. The body diode conduction threshold voltage of the third drive switch may be the sum of the target drive voltage and the body diode voltage drop of the third drive switch.

[0074] Figure 3A Schematically shows Figure 2 Equivalent circuit diagram of the circuit shown in the first phase.

[0075] like Figure 3AAs shown, in the first phase (the duration may be t0~t1), the first power switch S P1 , the fourth power switch S P4 and the second drive switch S C2 , the first node V P1 The voltage at is the input voltage V IN , the third node V PP and the second node V P2 The voltage at the transformer is 0V, and the resonant current i Lr From the first power switch S P1 Flows to the fourth power switch S P4 , the resonant current i on the secondary side of the transformer LLC Through the second load switch S2 for the output capacitor C O Charge.

[0076] Figure 3B Schematically shows Figure 2 Equivalent circuit diagram of the circuit shown in the first initial phase.

[0077] like Figure 3B As shown, in the first initial phase (the duration may be t1 to t2), before the end of the current first sub-cycle, the fourth power switch S is first turned off. P4 , the resonant current i of the primary side of the transformer Lr The second node V P2 and the third node V PP At the same time, charging is performed to the body diode conduction threshold voltage of the third drive switch. For example, when the body diode voltage drop is 0.7V, the body diode conduction threshold voltage may be PVDD+0.7V, and the body diode of the third drive switch is turned on.

[0078] Figure 3C Schematically shows Figure 2 Equivalent circuit diagram of the circuit shown in the charging phase.

[0079] like Figure 3C As shown, in the first charging phase (the duration may be t2 to t3), the third driving switch S C3 It is turned on in zero voltage switching (ZVS) mode, with low switching loss and the resonant current i Lr is the filter capacitor C PVDD Charge to ensure that the filter capacitor C PVDD The voltage is stabilized at the target driving voltage PVDD.

[0080] Figure 3D Schematically shows Figure 2 Equivalent circuit diagram of the circuit shown in the second phase.

[0081] like Figure 3DAs shown, in the second phase (the duration can be t3~t4), all switches are turned off, and the resonant current i Lr At the same time, the first node V P1 Discharges and becomes the second node V P2 Charge.

[0082] According to an embodiment of the present disclosure, the multiple phases within the second sub-period include a second initial phase. In the second initial phase, the resonant current charges the first node and the third node simultaneously until the body diode conduction threshold voltage of the third drive switch is reached, ensuring that the third drive switch is turned on in zero voltage mode, triggering the charging phase.

[0083] According to an embodiment of the present disclosure, the second sub-period may include the third phase, the second initial phase, the second charging phase and the fourth phase in sequence.

[0084] Figure 4A Schematically shows Figure 2 Equivalent circuit diagram of the circuit shown in the third phase.

[0085] like Figure 4A As shown, when the first node V P1 When the voltage at the node is discharged to be equal to the voltage at the third node VPP, the first driving switch S C1 It is turned on in ZVS mode, and the switching loss is small. And when the first node V P1 The voltage at the second node V P2 The voltage is charged to the input voltage V IN When the second power switch S P2 and the third power switch S P3 All are turned on in ZVS mode, and the circuit enters the second sub-cycle. In the third phase (the duration can be t4~t5), the resonant current i Lr From the third power switch S P3 Flows to the second power switch S P2 , the resonant circuit i on the secondary side of the transformer LLC Through the first load switch S1 is the load capacitor C O Charge.

[0086] Figure 4B Schematically shows Figure 2 Equivalent circuit diagram of the circuit shown in the second initial phase.

[0087] like Figure 4B As shown, in the second initial phase (the duration may be t5 to t6), the second power switch S is first turned off. P2 , the resonant current i of the primary side of the transformer Lr The first node V P1 and the third node V PPAt the same time, it is charged to the body diode conduction threshold voltage of the third drive switch. For example, when the body diode voltage drop is 0.7V, the body diode conduction threshold voltage may be PVDD+0.7V, and the body diode of the third drive switch is turned on.

[0088] Figure 4C Schematically shows Figure 2 Equivalent circuit diagram of the circuit shown in the second charging phase.

[0089] like Figure 4C As shown, in the second charging phase (the duration may be t6 to t7), the third driving switch S C3 Start in ZVS mode, the switching loss is small, and the resonant current i Lr is the filter capacitor C PVDD Charge to ensure that the filter capacitor C PVDD The voltage is stabilized at the target driving voltage PVDD.

[0090] Figure 4D Schematically shows Figure 2 Equivalent circuit diagram of the circuit shown in the fourth phase.

[0091] like Figure 4D As shown, in the fourth phase (the duration can be t7~t8), the second sub-cycle ends, all switches in the circuit are turned off, and the resonant current i Lr At the same time, the first node V P1 Charges and supplies the second node V P2 discharge.

[0092] Figure 5 Schematically shows Figure 2 Waveform diagram of the circuit shown.

[0093] like Figure 5 As shown, i Lm Indicates the excitation inductance L m The current, i SEC Represents the current on the secondary side of the transformer, i SC3 represents the current flowing through the third drive switch S C3 The current. V P1 and V P2 Generates alternating voltage to achieve input voltage V IN Inversion from DC to AC voltage. V P1 and V P2 There is a phase difference between them, which are alternately high level, driving the primary side of the transformer to generate a resonant current i Lr , so that the resonant unit oscillates at the resonant frequency, achieving soft switching conditions and reducing switching losses. The resonant current i Lr In the first charging phase and the second charging phase, the filter capacitor C PVDDCharging is the target driving voltage PVDD that stably supplies power to the circuit. The current i SEC In half-wave form, the secondary side of the transformer passes through the rectifier circuit to rectify the AC current induced by the secondary side of the transformer into a unidirectional current, which is the load capacitor C O powered by.

[0094] The circuit diagrams and waveform diagrams in the accompanying drawings illustrate the possible architectures, functions, and operations of the circuits according to the various embodiments of the present disclosure. Those skilled in the art will appreciate that the features described in the various embodiments of the present disclosure may be combined and / or combined in various ways, even if such combinations or combinations are not explicitly described in the present disclosure. In particular, without departing from the spirit and teachings of the present disclosure, the features described in the various embodiments of the present disclosure may be combined and / or combined in various ways. All such combinations and / or combinations fall within the scope of the present disclosure.

[0095] The above describes the embodiments of the present disclosure. However, these embodiments are for illustrative purposes only and are not intended to limit the scope of the present disclosure. Although each embodiment has been described separately above, this does not mean that the measures in each embodiment cannot be advantageously used in combination. Without departing from the scope of the present disclosure, those skilled in the art may make various substitutions and modifications, which should all fall within the scope of the present disclosure.

Claims

1. A transformer-based drive power supply circuit, comprising: a conversion module, comprising a transformer and a resonance unit connected to the primary side of the transformer, wherein the resonance unit is connected to the drive power supply module, and the conversion module is used to convert the received AC voltage and AC current into a target voltage and target current respectively; The driving power supply module includes a filter capacitor and multiple driving switches. The driving power supply module is configured to switch the conduction state of each of the multiple driving switches according to the current driving voltage of the filter capacitor and the target driving voltage required by the circuit, and dynamically adjust the resonant current generated by the resonant unit to the charging time of the filter capacitor, ensuring that the voltage of the filter capacitor is stable at the target driving voltage, and the timing of the target driving voltage is synchronized with the phase of the resonant current.

2. The circuit according to claim 1, wherein The driving power supply module is further configured to generate an error signal according to the current driving voltage and the target driving voltage required by the circuit; The error signal is used to adjust the duty ratios of the multiple phases within a single working cycle to adjust the resonant current generated by the resonant unit to the charging time of the filter capacitor, thereby stabilizing the voltage of the filter capacitor at the target driving voltage.

3. The circuit according to claim 2, wherein The multiple phases include a charging phase, the error signal includes a first error signal and a second error signal, and the driving power supply module generates the first error signal in response to the current driving voltage being less than the target driving voltage; The first error signal is used to increase the duty cycle of the charging phase, thereby increasing the charging time of the filter capacitor and increasing the current driving voltage to the target driving voltage.

4. The circuit according to claim 3, wherein The driving power supply module generates the second error signal in response to the current driving voltage being greater than the target driving voltage; The second error signal is used to reduce the duty cycle of the charging phase, shorten the charging time of the filter capacitor, and reduce the current driving voltage to the target driving voltage.

5. The circuit according to claim 4, wherein The circuit also includes an inverter module, which includes a first diagonal switch unit and a second diagonal switch unit. The first diagonal switch unit and the second diagonal switch unit each include multiple power switches. The target drive voltage provides a gate control signal for the multiple power switches. The inverter module is configured to control the first diagonal switch unit and the second diagonal switch unit to alternately conduct according to the respective duty cycles of the multiple phases, so as to invert the DC voltage into the AC voltage and the AC current, and drive the resonant unit to generate a periodic resonant current.

6. The circuit according to claim 5, wherein The first diagonal switch unit includes a first power switch and a fourth power switch, the second diagonal switch unit includes a second power switch and a third power switch, the first end of the first power switch, the first end of the second power switch and the resonant unit are commonly connected to a first node, and the first end of the third power switch, the first end of the fourth power switch and the resonant unit are commonly connected to a second node.

7. The circuit according to claim 6, wherein The multiple drive switches include a first drive switch, a second drive switch, and a third drive switch. The first end of the first drive switch is connected to the inverter module, the second end of the first drive switch, the first end of the third drive switch, and the first end of the second drive switch are commonly connected to a third node, the second end of the second drive switch is connected to the second node, the second end of the third drive switch is connected to the first plate of the filter capacitor, and the second plate of the filter capacitor is grounded.

8. The circuit according to claim 7, wherein The working cycle includes a first sub-cycle and a second sub-cycle. The multiple phases in the first sub-cycle include a first initial phase. In the first initial phase, the resonant current simultaneously charges the second node and the third node until the body diode conduction threshold voltage of the third drive switch is reached, ensuring that the third drive switch is turned on in zero voltage mode, triggering the charging phase.

9. The circuit according to claim 8, wherein The multiple phases within the second sub-period include a second initial phase. In the second initial phase, the resonant current simultaneously charges the first node and the third node until the body diode conduction threshold voltage of the third drive switch is reached, ensuring that the third drive switch is turned on in zero voltage mode, triggering the charging phase.

10. The circuit of claim 1, wherein The circuit further includes a rectifier module connected to the secondary side of the transformer. The rectifier module includes a plurality of load switches. The target driving voltage is used to power gate drivers of the plurality of load switches.

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