POWER CONVERTER

Abstract

A power converter includes a primary-side rectifying/filtering circuit, an AC-DC converter, a DC/DC converter, a primary-side controller, a secondary-side rectifying controller, and a secondary-side feedback controller. The primary-side rectifying/filtering circuit receives an input voltage, and rectifies and filters the input voltage into an adjusted input voltage. The AC-DC converter receives the adjusted input voltage. The primary-side controller provides a first control signal to control the AC-DC converter to convert the adjusted input voltage into a DC input voltage, and provides a second control signal to control the DC-DC converter. The secondary-side rectifying controller provides a third control signal to control the DC-DC converter to convert the DC input voltage into a conversion voltage to supply power to a load according to a gain condition. The secondary-side feedback controller receives a power demand signal provided by the load to control the primary-side controller and the secondary-side rectifying controller.

Description

BACKGROUND

Technical Field

The present disclosure relates to a power converter, and more particularly to a power converter that can operate in half-bridge or full-bridge circuit topologies to provide multiple output voltages.

Description of Related Art

The statements in this section merely provide background information related to the present disclosure and do not necessarily constitute prior art.

When the power is greater than 100 watts, the power supply products usually use the topology of PFC plus LLC. The main reason is that LLC has the characteristic of zero voltage switching, which enables the power supply products to operate at higher frequencies, thereby reducing the size of the magnetic components and reducing the size of the power supply products.

Such as the above-mentioned structure of the first stage PFC plus the second stage LLC is a very common power supply design structure. However, in response to the increasingly sophisticated technology, the voltages required are not the same when there are many 3C products. Therefore, the specifications of power supply products with different output voltages have become more and more popular. However, since the optimal efficiency operation point of LLC is the resonant frequency point, a stable input voltage and a stable output voltage must be maintained at this resonant frequency point, LLC is usually not an optimal solution under a single output voltage.

SUMMARY

An objective of the present disclosure is to provide a power converter to solve the problems of existing technology.

In order to achieve the above-mentioned objective, the power converter includes a primary-side rectifying/filtering circuit, an AC-DC converter, a DC-DC converter, a primary-side controller, a secondary-side rectifying controller, and a secondary-side feedback controller. The primary-side rectifying/filtering circuit receives an input voltage, and rectifies and filters the input voltage into an adjusted input voltage. The AC-DC converter is coupled to the primary-side rectifying/filtering circuit, and receives the adjusted input voltage. The DC-DC converter is coupled to the AC-DC converter. The primary-side controller is coupled to the AC-DC converter and the DC-DC converter, and provides a first control signal to control the AC-DC converter to convert the adjusted input voltage into a DC input voltage, and provides a second control signal to control the DC-DC converter. The secondary-side rectifying controller is coupled to the DC-DC converter, and provides a third control signal to control the DC-DC converter to convert the DC input voltage into a conversion voltage to supply power to a load accord to a gain condition. The secondary-side feedback controller is coupled to the primary-side controller and the secondary-side rectifying controller, and the secondary-side feedback controller receives a power demand signal provided by the load to control the primary-side controller and the secondary-side rectifying controller.

In one embodiment, the secondary-side feedback controller provides a feedback control signal to the primary-side controller, and provides a rectifying control signal to the secondary-side rectifying controller. The feedback control signal includes an AC-DC feedback control signal and a DC-DC feedback control signal. The primary-side controller controls the AC-DC converter according to the AC-DC feedback control signal, controls the DC-DC converter according to the DC-DC feedback control signal, and controls the secondary-side rectifying controller and adjusts the gain condition according to the rectifying control signal.

In one embodiment, the DC-DC converter includes a primary-side isolating circuit and a secondary-side isolating circuit. The primary-side isolating circuit is coupled to the AC-DC converter and the primary-side controller, and receives the second control signal and the DC input voltage. The secondary-side isolating circuit is coupled to the secondary-side rectifying controller, and isolatedly converts the DC input voltage.

In one embodiment, the primary-side isolating circuit includes a bridge switching circuit and a resonance circuit. The primary-side isolating circuit includes a bridge synchronous rectifying circuit and a step-down conversion circuit.

In one embodiment, the bridge switching circuit includes an upper switch and a lower switch. A first end of the upper switch is coupled to the AC-DC converter. A first end of the lower switch is coupled to a second end of the upper switch and the resonance circuit. The primary-side controller provides the second control signal to control the upper switch and the lower switch.

In one embodiment, the bridge synchronous rectifying circuit includes a first switch, a second switch, a third switch, a fourth switch, a first main resonance inductor, a second main resonance inductor, a first auxiliary resonance inductor, and a second auxiliary resonance inductor. A first end of the first auxiliary resonance inductor is coupled to a second end of the first switch, a second end of the first auxiliary resonance inductor is coupled to a first end of the second switch and a second end of the first main resonance inductor; a first end of the second auxiliary resonance inductor is coupled to a second end of the third switch, a second end of the second auxiliary resonance inductor is coupled to a first end of the fourth switch and a first end of the second main resonance inductor; a first end of the first main resonance inductor is coupled to a second end of the second main resonance inductor. A first end of the third switch coupled to a first end of the first switch and the step-down conversion circuit; a second end of the fourth switch is coupled to a second end of the second switch and the step-down conversion circuit. The secondary-side rectifying controller provides the third control signal to control the first switch, the second switch, the third switch, and the fourth switch.

In one embodiment, the bridge synchronous rectifying circuit further includes a first capacitor and a second capacitor. A first end of the first capacitor is coupled to the third switch. A first end of the second capacitor is coupled to a second end of the first capacitor, and a second end of the second capacitor is coupled to the fourth switch.

In one embodiment, the step-down conversion circuit includes a fifth switch, a sixth switch, a diode, an inductor, and a capacitor. A first end of the fifth switch is coupled to the first end of the third switch. A first end of the sixth switch is coupled to the first end of the first main resonance inductor and the second end of the second main resonance inductor, and a second end of the sixth switch is coupled to a second end of the fifth switch. A cathode of the diode is coupled to the second end of the fifth switch and the second end of the sixth switch. A first end of the inductor is coupled to the cathode of the diode. A first end of the capacitor is coupled to a second end of the inductor, and a second end of the capacitor is coupled to an anode of the diode and a second end of the fourth switch.

In one embodiment, when the conversion voltage is a first voltage, the first switch and the third switch are turned off, and the second switch and the fourth switch are alternately switched on so that the first main resonance inductor or the second main resonance inductor is excited.

In one embodiment, when the second switch is turned on, a first excitation path including the second switch, the first main resonance inductor, and the step-down conversion circuit is formed to excite the first main resonance inductor; when the fourth switch is turned on, a second excitation path comprising the fourth switch, the second main resonance inductor, and the step-down conversion circuit is formed to excite the second main resonance inductor.

In one embodiment, when the conversion voltage is a first voltage, the second switch and the fourth switch are turned off, and the first switch and the third switch are alternately switched on so that the first main resonance inductor or the second main resonance inductor is excited.

In one embodiment, when the first switch is turned on, a third excitation path including the first switch, the first main resonance inductor, and the step-down conversion circuit is formed to excite the first main resonance inductor; when the third switch is turned on, a fourth excitation path comprising the third switch, the second main resonance inductor, and the step-down conversion circuit is formed to excite the second main resonance inductor.

In one embodiment, when the conversion voltage is a second voltage, the first switch and the fourth switch are simultaneously turned on and turned off, the second switch and the third switch are simultaneously turned on and turned off, and the first switch and the third switch are alternately switched on so that the first main resonance inductor and the second main resonance inductor, and the first auxiliary resonance inductor or the second auxiliary resonance inductor are excited.

In one embodiment, when the first switch and the fourth switch are simultaneously turned on, a first excitation path including the first switch, the first auxiliary resonance inductor, the first main resonance inductor, the second main resonance inductor, the fourth switch, and the step-down conversion circuit is formed; when the second switch and the third switch are simultaneously turned on, a second excitation path comprising the second switch, the first main resonance inductor, the second main resonance inductor, the second auxiliary resonance inductor, the third switch, and the step-down conversion circuit is formed.

In one embodiment, an operation frequency of the primary-side isolating circuit is greater than a resonance frequency to adjust the output voltage of the power converter.

In one embodiment, a voltage of a front-stage power factor correction circuit is decreased to adjust the output voltage of the power converter.

In one embodiment, when the conversion voltage is less than the first voltage, the step-down conversion circuit is turned on by the fifth switch and the sixth switch.

In one embodiment, when the conversion voltage is less than the second voltage, the step-down conversion circuit is turned on by the fifth switch and the sixth switch.

In one embodiment, the step-down conversion circuit is used to convert the conversion voltage into a DC output voltage.

In one embodiment, a duty cycle of the fifth switch or a duty cycle of the sixth switch is controlled to step down the conversion voltage into the DC output voltage with different magnitudes.

Accordingly, the power converter can operate in half-bridge or full-bridge circuit topologies to flexibly provide multiple output voltages. Moreover, the output voltage can meet the requirements of a wider range of voltages by the design of different winding turns ratios of the first main resonance inductor, the second main resonance inductor, the first auxiliary resonance inductor, and the second auxiliary resonance inductor.

It is to be understood that both the foregoing general description and the following detailed description are exemplary, and are intended to provide further explanation of the present disclosure as claimed. Other advantages and features of the present disclosure will be apparent from the following description, drawings and claims.

BRIEF DESCRIPTION OF DRAWINGS

The present disclosure can be more fully understood by reading the following detailed description of the embodiment, with reference made to the accompanying drawing as follows:

FIG. 1 is a structural block diagram of a power converter according to the present disclosure.

FIG. 2 is a detailed block diagram of the power converter according to the present disclosure.

FIG. 3 and FIG. 4 are circuit diagrams of a DC-DC converter according to the present disclosure.

DETAILED DESCRIPTION

Reference will now be made to the drawing figures to describe the present disclosure in detail. It will be understood that the drawing figures and exemplified embodiments of present disclosure are not limited to the details thereof.

Please refer to FIG. 1 and FIG. 2, which respectively show a structural block diagram and a detailed block diagram of a power converter according to the present disclosure. The power converter with step-down and step-up (buck-boost) conversion includes a primary-side rectifying/filtering circuit 1, an AC-DC converter 2, a DC-DC converter 3, a primary-side controller 4, a secondary-side rectifying controller 5, and a secondary-side feedback controller 6.

The primary-side rectifying/filtering circuit 1 receive an input voltage V_IN, and rectifies and filters the input voltage V_IN into an adjusted input voltage V_INRF. Specifically, the primary-side rectifying/filtering circuit 1 includes a primary-side rectifying circuit and a primary-side filtering circuit (not shown). The primary-side rectifying circuit is used to rectify the input voltage V_IN. The primary-side filtering circuit is sued to filter the rectified input voltage V_IN to output the adjusted input voltage V_INRF to the AC-DC converter 2.

The AC-DC converter 2 is coupled to the primary-side rectifying/filtering circuit 1, and receives the adjusted input voltage V_INRF outputted from the primary-side rectifying/filtering circuit 1.

The DC-DC converter 3 is coupled to the AC-DC converter 2. Please refer to FIG. 3 and FIG. 4, which show circuit diagrams of a DC-DC converter according to the present disclosure. Specifically, the DC-DC converter 3 includes a primary-side isolating circuit 31 and a secondary-side isolating circuit 32. The primary-side isolating circuit 31 is coupled to the AC-DC converter 2 and the primary-side controller 4, and receives a second control signal S_C2 and the DC input voltage V_INDC. The secondary-side isolating circuit 32 is coupled to the secondary-side rectifying controller 5, and isolatedly converts the DC input voltage V_INDC.

The primary-side isolating circuit 31 includes a bridge switching circuit 311 and a resonance circuit 312. The bridge switching circuit 311 includes an upper switch Q_H and a lower switch Q_L. A first end of the upper switch Q_H is coupled to the AC-DC converter 2. A first end of the lower switch Q_L is coupled to a second end of the upper switch Q_H and the resonance circuit 312. The primary-side controller 4 provides the second control signal S_C2 to control the upper switch Q_H and the lower switch Q_L.

The primary-side isolating circuit 32 includes a bridge synchronous rectifying circuit 321 and a step-down conversion circuit 322. The bridge synchronous rectifying circuit 321 includes a first switch Q₁, a second switch Q₂, a third switch Q₃, a fourth switch Q₄, a first main resonance inductor W₁, a second main resonance inductor W₁₂, a first auxiliary resonance inductor W₂₁, and a second auxiliary resonance inductor W₂₂. In particular, the first main resonance inductor W₁, the second main resonance inductor W₁₂, the first auxiliary resonance inductor W₂₁, and the second auxiliary resonance inductor W₂₂ are respectively realized by main windings and auxiliary windings of the same inductive device (for example, but not limited to, a transformer). Therefore, voltages on the first main resonance inductor W₁₁, the second main resonance inductor W₁₂, the first auxiliary resonance inductor W₂₁, and the second auxiliary resonance inductor W₂₂ are proportional to the corresponding winding turns ratios.

A first end of the first auxiliary resonance inductor W₂₁ is coupled to the second end of the first switch Q₁, a second end of the first auxiliary resonance inductor W₂₁ is coupled to a first end of the second switch Q₂ and a first end of the first main resonance inductor W₁₁. A first end of the second auxiliary resonance inductor W₂₂ is coupled to the second end of the third switch Q₃, a second end of the second auxiliary resonance inductor W₂₂ is coupled to a first end of the fourth switch Q₄ and a first end of the second main resonance inductor W₁₂. In one embodiment, for example, but not limited to, the first ends of the first main resonance inductor W₁₁, the second main resonance inductor W₁₂, the first auxiliary resonance inductor W₂₁, and the second auxiliary resonance inductor W₂₂ are dotted ends; the second ends of the first main resonance inductor W₁₁, the second main resonance inductor W₁₂, the first auxiliary resonance inductor W₂₁, and the second auxiliary resonance inductor W₂₂ are non-dotted ends.

A first end of the third switch Q₃ is coupled to a first end of the first switch Q₁ and the step-down conversion circuit 322. A second end of the fourth switch Q₄ is coupled to a second end of the second switch Q₂ and the step-down conversion circuit 322. The secondary-side rectifying controller 5 provides a third control signal S_C3 to control the first switch Q₁, the second switch Q₂, the third switch Q₃, and the fourth switch Q₄.

The bridge synchronous rectifying circuit 321 further includes a first capacitor C₁ and a second capacitor C₂. A first end of the first capacitor C₁ is coupled to the first end of the third switch Q₃ and the first end of the first switch Q₁. A first end of the second capacitor C₂ is coupled to a second end of the first capacitor C₁, and the first end of the first main resonance inductor W₁₁ and the second end of the second main resonance inductor W₁₂ (i.e., a common-connected end of the first main resonance inductor W₁₁ and the second main resonance inductor W₁₂). A second end of the second capacitor C₂ is coupled to the second end of the fourth switch Q₄ and the second end of the second switch Q₂.

The step-down conversion circuit 322 is used to convert a conversion voltage V_CON into a DC output voltage V_OUTDC. The step-down conversion circuit 322 includes a fifth switch Q₅, a sixth switch Q₆, a diode D, an inductor L, and a capacitor C. A first end of the fifth switch Q₅ is coupled to the first end of the third switch Q₃ and the first end of the first capacitor C₁. A first end of the sixth switch Q₆ is coupled to the first end of the first main resonance inductor W₁₁ and the second end of the second main resonance inductor W₁₂, and a second end of the sixth switch Q₆ is coupled to a second end of the fifth switch Q₅. A cathode of the diode D is coupled to the second end of the fifth switch Q₅ and the second end of the sixth switch Q₆. A first end of the inductor L is coupled to the cathode of the diode D. A first end of the capacitor C is coupled to a second end of the inductor L, and a second end of the capacitor C is coupled to an anode of the diode D and a second end of the fourth switch Q₄. In one embodiment, the sixth switch Q₆ may be implemented with back-to-back semiconductor components, but this does not limit the present disclosure.

The primary-side controller 4 is coupled to the AC-DC converter 2 and the DC-DC converter 3, and provides a first control signal Sci to control the AC-DC converter 2 to convert the adjusted input voltage V_INRF into a DC input voltage V_INDC, and provide the second control signal S_C2 to control the DC-DC converter 3.

The secondary-side rectifying controller 5 is coupled to the DC-DC converter 3, and provides the third control signal S_C3 to control the DC-DC converter 3 to convert the DC input voltage V_INDC into the conversion voltage V_CON to supply power to a load 7 accord to a gain condition.

The secondary-side feedback controller 6 is coupled to the primary-side controller 4 and the secondary-side rectifying controller 5. The secondary-side feedback controller 6 receives a power demand signal S_LP provided by the load 7 to control the primary-side controller 4 and the secondary-side rectifying controller 5. Specifically, the secondary-side feedback controller 6 provides a feedback control signal to the primary-side controller 4, and provides a rectifying control signal S_CSR to the secondary-side rectifying controller 5. The feedback control signal includes an AC-DC feedback control signal S_CAD and a DC-DC feedback control signal S_CDD.

The primary-side controller 4 controls the AC-DC converter 2 according to the AC-DC feedback control signal S_CAD, controls the DC-DC converter 3 according to the DC-DC feedback control signal S_CDD, and controls the secondary-side rectifying controller 5 and adjusts the gain condition according to the rectifying control signal S_CSR.

When the bridge synchronous rectifying circuit 321 operates as a half-bridge circuit, the conversion voltage V_CON is a first voltage, such as but not limited to 20 volts, the third control signal S_C3 turns off the first switch Q₁ and the third switch Q₃, and alternately switches on the second switch Q₂ and the fourth switch Q₄ so that the first main resonance inductor W₁₁ or the second main resonance inductor W₁₂ is excited. In this embodiment, when the second switch Q₂ is turned on, a first excitation path including the second switch Q₂, the first main resonance inductor W₁₁, and the step-down conversion circuit 322 is formed to excite the first main resonance inductor W₁₁. When the fourth switch Q₄ is turned on, a second excitation path including the fourth switch Q₄, the second main resonance inductor W₁₂, and the step-down conversion circuit 322 is formed to excite the second main resonance inductor W₁₂.

In a symmetrical circuit operation: when the conversion voltage V_CON is a first voltage, the third control signal S_C3 turns off the second switch Q₂ and the fourth switch Q₄, and alternately switches on the first switch Q₁ and the third switch Q₃ so that the first main resonance inductor W₁₁ or the second main resonance inductor W₁₂ is excited. In this embodiment, when the first switch Q₁ is turned on, a third excitation path including the first switch Q₁, the first main resonance inductor W₁₁, and the step-down conversion circuit 322 is formed to excite the first main resonance inductor W₁₁. When the third switch Q₃ is turned on, a fourth excitation path including the third switch Q₃, the second main resonance inductor W₁₂, and the step-down conversion circuit 322 is formed to excite the second main resonance inductor W₁₂.

When the conversion voltage V_CON is less than the first voltage (i.e., less than 20 volts), the step-down conversion circuit 322 is turned on by the fifth switch Q₅ and the sixth switch Q₆. Specifically, a duty cycle of the fifth switch Q₅ or a duty cycle of the sixth switch Q₆ is controlled to step down the conversion voltage V_CON into the DC output voltage V_OUTDC with different magnitudes.

However, under the full-bridge operation that requires double voltage output, when only the first main resonance inductor W₁₁ and the second main resonance inductor W₁₂ are used (that is, the first auxiliary resonance inductor W₂₁ and the second auxiliary resonance inductor W₂₂ are absent), there is a fixed multiple between the output voltage and the input voltage (for example, two times). Therefore, to realize the voltage relationship between the output voltage and the input voltage that is not a fixed multiple, for example, the input voltage is 20 volts and the output voltage of 48 volts, it is necessary to increase the input voltage of the front-stage power factor correction (PFC) circuit (for example, from 400 volts to 480 volts) so as to make it possible to provide the output voltage of 48 volts through the two-time voltage gain. However, the volume of the bulk capacitor must be increased to increase the voltage through the front-stage PFC, which is not conducive to the design of the miniaturized system.

Therefore, the present disclosure further optimizes the circuit design by using the first auxiliary resonance inductor W₂₁ and the second auxiliary resonance inductor W₂₂. Specifically, by designing winding turns ratios of the first main resonance inductor W₁₁, the second main resonance inductor W₁₂, the first auxiliary resonance inductor W₂₁, and the second auxiliary resonance inductor W₂₂ to achieve the circuit design optimization.

For example, but not limited to, winding turns ratios of the first main resonance inductor W₁₁, the second main resonance inductor W₁₂, the first auxiliary resonance inductor W₂₁ are designed to be 2:2:1:1, and therefore under the full-bridge operation (i.e., under the double-voltage operation), a voltage across the first main resonance inductor W₁₁ is 20 volts (referred to as a first voltage), a voltage across the second main resonance inductor W₁₂ is 20 volts (referred to as a second voltage), a voltage across the first auxiliary resonance inductor W₂₁ is 10 volts (referred to as a third voltage), and a voltage across the second auxiliary resonance inductor W₂₂ is 10 volts (referred to as a fourth voltage). Under the full-bridge operation in which the second switch Q₂ and the third switch Q₃ are turned on, the sum of voltages across the first capacitor C₁ and the second capacitor C₂ is 50 volts, that is, the sum of the first voltage, the second voltage, and the fourth voltage. Similarly, under the full-bridge operation in which the first switch Q₁ and the fourth switch Q₄ are turned on, the sum of voltages across the first capacitor C₁ and the second capacitor C₂ is 50 volts, that is, the sum of the first voltage, the second voltage, and the third voltage.

In the above-mentioned output voltage state, the output voltage of 50 volts may be corrected/adjusted to the output voltage of 48 volts through two manners. The first manner: by increasing an operation frequency of the LLC circuit (that is, the primary-side isolating circuit 31) to be greater than the resonance frequency, the voltage gain will be slightly decreased to achieve the output voltage of 48 volts. Therefore, it is no longer necessary to increase the voltage of the front-stage PFC so it is not necessary to select a large capacitor with a larger volume. The second manner: without increasing the operation frequency of the LLC circuit, the output voltage of 48 volts can be directly outputted by decreasing the voltage of the front-stage PFC (for example, from 400 volts to 380 volts) so as to make it possible to provide the output voltage of 48 volts through the two-time voltage gain. That is, the first voltage and the second voltage are slightly less than 20 volts, and the third voltage and the fourth voltage are slightly less than 10 volts, and therefore the sum of the first voltage, the second voltage, and the third voltage or the sum of the first voltage, the second voltage, and the fourth voltage directly reaches 48 volts. Accordingly, the volume of the large capacitor can be reduced, which is beneficial to the design of the design of the miniaturized system, and also the power conversion efficiency can be improved.

Moreover, in the present disclosure, the output voltage can meet the requirements of a wider range of voltages by the design of different winding turns ratios of the first main resonance inductor W₁₁, the second main resonance inductor W₁₂, the first auxiliary resonance inductor W₂₁, and the second auxiliary resonance inductor W₂₂.

When the bridge synchronous rectifying circuit 321 operates as a full-bridge circuit to provide the double voltage output, the conversion voltage V_CON is a second voltage, such as but not limited to 48 or 36 volts, the third control signal S_C3 simultaneously turns on and turns off the first switch Q₁ and the fourth switch Q₄, simultaneously turns on and turns off the second switch Q₂ and the third switch Q₃, and alternately switches on the first switch Q₁ and the second switch Q₂ so that the first main resonance inductor W₁₁ and the second main resonance inductor W₁₂, and the first auxiliary resonance inductor W₂₁ or the second auxiliary resonance inductor W₂₂. Specifically, when the first switch Q₁ and the fourth switch Q₄ are simultaneously turned on, the first excitation path includes the first switch Q₁, the first auxiliary resonance inductor W₂₁, the first main resonance inductor W₁₁, the second main resonance inductor W₁₂, the fourth switch Q₄, and the step-down conversion circuit 322 so that the first main resonance inductor W₁₁, the second main resonance inductor W₁₂, and the first auxiliary resonance inductor W₂₁ are simultaneously excited. When the second switch Q₂ and the third switch Q₃ are simultaneously turned on, the second excitation path includes the second switch Q₂, the first main resonance inductor W₁₁, the second main resonance inductor W₁₂, and the second auxiliary resonance inductor W₂₂, the third switch Q₃, and the step-down conversion circuit 322 so that the first main resonance inductor W₁₁, the second main resonance inductor W₁₂, and the second auxiliary resonance inductor W₂₂ are simultaneously excited.

When the conversion voltage V_CON is less than the second voltage (i.e., less than 48 or 36 volts), the step-down conversion circuit 322 is turned on by the fifth switch Q₅ and the sixth switch Q₆. Specifically, a duty cycle of the fifth switch Q₅ or a duty cycle of the sixth switch Q₆ is controlled to step down the conversion voltage V_CON into the DC output voltage V_OUTDC with different magnitudes.

Accordingly, the power converter can operate in half-bridge or full-bridge circuit topologies to flexibly provide multiple output voltages. Moreover, the output voltage can meet the requirements of a wider range of voltages by the design of different winding turns ratios of the first main resonance inductor W₁₁, the second main resonance inductor W₁₂, the first auxiliary resonance inductor W₂₁, and the second auxiliary resonance inductor W₂₂.

Although the present disclosure has been described with reference to the preferred embodiment thereof, it will be understood that the present disclosure is not limited to the details thereof. Various substitutions and modifications have been suggested in the foregoing description, and others will occur to those of ordinary skill in the art. Therefore, all such substitutions and modifications are intended to be embraced within the scope of the present disclosure as defined in the appended claims.

Claims

1. A power converter, comprising: a primary-side rectifying/filtering circuit, configured to receive an input voltage, and rectify and filter the input voltage into an adjusted input voltage,an AC-DC converter, coupled to the primary-side rectifying/filtering circuit, and configured to receive the adjusted input voltage,a DC-DC converter, coupled to the AC-DC converter,a primary-side controller, coupled to the AC-DC converter and the DC-DC converter, and configured to provide a first control signal to control the AC-DC converter to convert the adjusted input voltage into a DC input voltage, and provide a second control signal to control the DC-DC converter,a secondary-side rectifying controller, coupled to the DC-DC converter, and configured to provide a third control signal to control the DC-DC converter to convert the DC input voltage into a conversion voltage to supply power to a load accord to a gain condition, anda secondary-side feedback controller, coupled to the primary-side controller and the secondary-side rectifying controller, and the secondary-side feedback controller configured to receive a power demand signal provided by the load to control the primary-side controller and the secondary-side rectifying controller.

2. The power converter as claimed in claim 1, wherein the secondary-side feedback controller provides a feedback control signal to the primary-side controller, and provides a rectifying control signal to the secondary-side rectifying controller, wherein the feedback control signal comprises an AC-DC feedback control signal and a DC-DC feedback control signal, wherein the primary-side controller controls the AC-DC converter according to the AC-DC feedback control signal, controls the DC-DC converter according to the DC-DC feedback control signal, and controls the secondary-side rectifying controller and adjusts the gain condition according to the rectifying control signal.

3. The power converter as claimed in claim 1, wherein the DC-DC converter comprises: a primary-side isolating circuit, coupled to the AC-DC converter and the primary-side controller, and configured to receive the second control signal and the DC input voltage, anda secondary-side isolating circuit, coupled to the secondary-side rectifying controller, and configured to isolatedly convert the DC input voltage.

4. The power converter as claimed in claim 3, wherein the primary-side isolating circuit comprises a bridge switching circuit and a resonance circuit; the primary-side isolating circuit comprises a bridge synchronous rectifying circuit and a step-down conversion circuit.

5. The power converter as claimed in claim 4, wherein the bridge switching circuit comprises: an upper switch, a first end of the upper switch coupled to the AC-DC converter, anda lower switch, a first end of the lower switch coupled to a second end of the upper switch and the resonance circuit,wherein the primary-side controller provides the second control signal to control the upper switch and the lower switch.

6. The power converter as claimed in claim 4, wherein the bridge synchronous rectifying circuit comprises: a first switch, a second switch, a third switch, a fourth switch;a first main resonance inductor and a second main resonance inductor; anda first auxiliary resonance inductor and a second auxiliary resonance inductor;wherein a first end of the first auxiliary resonance inductor is coupled to a second end of the first switch, a second end of the first auxiliary resonance inductor is coupled to a first end of the second switch and a second end of the first main resonance inductor; a first end of the second auxiliary resonance inductor is coupled to a second end of the third switch, a second end of the second auxiliary resonance inductor is coupled to a first end of the fourth switch and a first end of the second main resonance inductor; a first end of the first main resonance inductor is coupled to a second end of the second main resonance inductor;wherein a first end of the third switch coupled to a first end of the first switch and the step-down conversion circuit; a second end of the fourth switch is coupled to a second end of the second switch and the step-down conversion circuit;wherein the secondary-side rectifying controller provides the third control signal to control the first switch, the second switch, the third switch, and the fourth switch.

7. The power converter as claimed in claim 6, wherein the bridge synchronous rectifying circuit further comprises: a first capacitor, a first end of the first capacitor coupled to the third switch, anda second capacitor, a first end of the second capacitor coupled to a second end of the first capacitor, and a second end of the second capacitor coupled to the fourth switch.

8. The power converter as claimed in claim 6, wherein the step-down conversion circuit comprises: a fifth switch, a first end of the fifth switch coupled to the first end of the third switch,a sixth switch, a first end of the sixth switch coupled to the first end of the first main resonance inductor and the second end of the second main resonance inductor, and a second end of the sixth switch coupled to a second end of the fifth switch,a diode, a cathode of the diode coupled to the second end of the fifth switch and the second end of the sixth switch,an inductor, a first end of the inductor coupled to the cathode of the diode, anda capacitor, a first end of the capacitor coupled to a second end of the inductor, and a second end of the capacitor coupled to an anode of the diode and a second end of the fourth switch.

9. The power converter as claimed in claim 6, wherein when the conversion voltage is a first voltage, the first switch and the third switch are turned off, and the second switch and the fourth switch are alternately switched on so that the first main resonance inductor or the second main resonance inductor is excited.

10. The power converter as claimed in claim 9, wherein when the second switch is turned on, a first excitation path comprising the second switch, the first main resonance inductor, and the step-down conversion circuit is formed to excite the first main resonance inductor; when the fourth switch is turned on, a second excitation path comprising the fourth switch, the second main resonance inductor, and the step-down conversion circuit is formed to excite the second main resonance inductor.

11. The power converter as claimed in claim 6, wherein when the conversion voltage is a first voltage, the second switch and the fourth switch are turned off, and the first switch and the third switch are alternately switched on so that the first main resonance inductor or the second main resonance inductor is excited.

12. The power converter as claimed in claim 11, wherein when the first switch is turned on, a third excitation path comprising the first switch, the first main resonance inductor, and the step-down conversion circuit is formed to excite the first main resonance inductor; when the third switch is turned on, a fourth excitation path comprising the third switch, the second main resonance inductor, and the step-down conversion circuit is formed to excite the second main resonance inductor.

13. The power converter as claimed in claim 6, wherein when the conversion voltage is a second voltage, the first switch and the fourth switch are simultaneously turned on and turned off, the second switch and the third switch are simultaneously turned on and turned off, and the first switch and the third switch are alternately switched on so that the first main resonance inductor and the second main resonance inductor, and the first auxiliary resonance inductor or the second auxiliary resonance inductor are excited.

14. The power converter as claimed in claim 12, wherein when the first switch and the fourth switch are simultaneously turned on, a first excitation path comprising the first switch, the first auxiliary resonance inductor, the first main resonance inductor, the second main resonance inductor, the fourth switch, and the step-down conversion circuit is formed; when the second switch and the third switch are simultaneously turned on, a second excitation path comprising the second switch, the first main resonance inductor, the second main resonance inductor, the second auxiliary resonance inductor, the third switch, and the step-down conversion circuit is formed.

15. The power converter as claimed in claim 6, wherein an operation frequency of the primary-side isolating circuit is greater than a resonance frequency to adjust the output voltage of the power converter.

16. The power converter as claimed in claim 6, wherein a voltage of a front-stage power factor correction circuit is decreased to adjust the output voltage of the power converter.

17. The power converter as claimed in claim 9, wherein when the conversion voltage is less than the first voltage, the step-down conversion circuit is turned on by the fifth switch and the sixth switch.

18. The power converter as claimed in claim 13, wherein when the conversion voltage is less than the second voltage, the step-down conversion circuit is turned on by the fifth switch and the sixth switch.

19. The power converter as claimed in claim 6, wherein the step-down conversion circuit is used to convert the conversion voltage into a DC output voltage.

20. The power converter as claimed in claim 19, wherein a duty cycle of the fifth switch or a duty cycle of the sixth switch is controlled to step down the conversion voltage into the DC output voltage with different magnitudes.