Switched power supply architecture

Abstract

A switching power supply architecture includes a power factor correction circuit, an LLC resonant conversion circuit, and a wide input range buck circuit. The power factor correction circuit is connected to an AC power source and provides a first output voltage to a subsequent stage based on an output power. The LLC resonant conversion circuit is connected to a subsequent stage of the power factor correction circuit and receives the first output voltage. The LLC resonant conversion circuit provides a second output voltage to the subsequent stage. The LLC resonant conversion circuit is open loop controlled and operates at a series resonant frequency point to maintain the second output voltage in a full resonance mode. The wide input range buck circuit is connected to a subsequent stage of the LLC resonant conversion circuit and receives the second output voltage. The wide input range buck circuit is connected to at least one load.

Description

Technical Field

[0001] This utility model relates to a switching power supply architecture, and more particularly to a switching power supply architecture that can avoid the concentration of waste heat in a specific circuit. Background Technology

[0002] Current switching power supply architectures are disclosed in patents such as TW201505348A, CN116885952A, and CN110504847A from Taiwan, China.

[0003] Current switched-mode power supply architectures primarily consist of a power factor correction circuit and a resonant converter circuit. In this architecture, power losses are mainly distributed across the power factor correction circuit and the resonant converter circuit. The power factor correction circuit's losses primarily occur under conditions of low input voltage and high output voltage. The purpose of maintaining a high output voltage in the power factor correction circuit is to meet the output regulation requirements of the resonant converter circuit. Currently, the resonant converter circuit in switched-mode power supply architectures is generally implemented as an isolated LLC resonant circuit. The losses in this circuit are mainly generated by the transformer and synchronous rectification. Furthermore, since the output voltage of this resonant converter circuit is 12V, if the downstream load demand increases, the current will increase significantly, leading to a substantial increase in transformer secondary copper losses and synchronous rectification losses.

[0004] As mentioned above, current switching power supply architectures suffer from concentrated losses in certain circuits, and waste heat also accumulates in these circuits. This makes it difficult to apply current switching power supply architectures to fanless power supplies because they typically use an active heatsink (such as a cooling fan) for heat dissipation. Utility Model Content

[0005] The main purpose of this invention is to solve the problem that waste heat in the current switching power supply architecture is concentrated in the power factor correction circuit and the resonant conversion circuit.

[0006] To achieve the above objectives, this utility model provides a switching power supply architecture that connects to an AC power source and supplies power to at least one load. The switching power supply architecture has an output power. The switching power supply architecture includes a power factor correction circuit, an LLC resonant converter circuit, and a wide input range buck circuit. The power factor correction circuit is connected to the AC power source and adjusts a first output voltage supplied to the subsequent stage based on the output power. The LLC resonant converter circuit is the subsequent stage of the power factor correction circuit and receives the first output voltage. The LLC resonant converter circuit provides a second output voltage to the subsequent stage. The LLC resonant converter circuit is open-loop controlled and operates at its series resonant frequency to maintain the second output voltage in full resonant mode. The wide input range buck circuit is the subsequent stage of the LLC resonant converter circuit and receives the second output voltage. The wide input range buck circuit is connected to the at least one load.

[0007] In one embodiment, the power factor correction circuit has a light-load output mode and a heavy-load output mode. The power factor correction circuit operates in the light-load output mode or the heavy-load output mode based on the output power compared to a comparison value. In the light-load output mode, the power factor correction circuit makes the first output voltage greater than the peak value of an input voltage provided by the AC power supply. In the heavy-load output mode, the power factor correction circuit adjusts the first output voltage based on the output power.

[0008] In one embodiment, the switching power supply architecture includes a flyback converter circuit that serves as the stage after the power factor correction circuit and receives the first output voltage, a transformer connected to the flyback converter circuit, and an auxiliary power output circuit that serves as the stage after the transformer, the auxiliary power output circuit providing a standby power.

[0009] In one embodiment, the switching power supply architecture includes a secondary power conversion circuit as a downstream stage of the wide input range buck circuit, the secondary power conversion circuit providing at least a third output voltage.

[0010] In one embodiment, the switching power supply architecture includes a first management circuit as an accessory circuit to the LLC resonant converter circuit, a second management circuit as an accessory circuit to the power factor correction circuit, and a signal isolator connecting the first management circuit and the second management circuit. The first management circuit is capable of receiving a power-on signal from the at least one load. The first management circuit and the second management circuit are capable of transmitting signals via the signal isolator. The first management circuit provides a power-normal signal to the at least one load.

[0011] In one embodiment, the switching power supply architecture does not include a cooling fan for providing heat dissipation at least for the LLC resonant converter circuit and the wide input range buck circuit.

[0012] In one embodiment, the first output voltage ranges from 130 volts to 420 volts, and the second output voltage ranges from 13 volts to 60 volts.

[0013] Compared to conventional power supplies, this invention, through the aforementioned implementation, has the following advantages: The switching power supply architecture avoids excessive losses in certain circuits, distributing losses across different circuit stages to achieve heat dissipation. Furthermore, the LLC resonant converter circuit in this switching power supply architecture employs open-loop control and operates in full resonant mode, simplifying the control of the LLC resonant converter circuit compared to conventional designs. Moreover, this switching power supply architecture effectively reduces losses and improves the overall efficiency of the switching power supply architecture, making it suitable for application in high-power-density power supplies. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of a unit in the first embodiment of the switching power supply architecture of this utility model;

[0015] Figure 2 This is a schematic diagram of a unit in the second embodiment of the switching power supply architecture of this utility model;

[0016] Figure 3 This is a schematic diagram of a third embodiment of the switching power supply architecture of this utility model.

[0017] [Symbol Explanation]

[0018] 20: Switching power supply architecture

[0019] 21: Power Factor Correction Circuit

[0020] 211: First output voltage

[0021] 22: LLC resonant converter circuit

[0022] 221: Second output voltage

[0023] 23: Wide input range buck circuit

[0024] 24: Flyback Conversion Circuit

[0025] 25: Transformer

[0026] 26: Auxiliary power supply output circuit

[0027] 27: Secondary power conversion circuit

[0028] 28: First Management Circuit

[0029] 29: Second Management Circuit

[0030] 30: Signal isolator

[0031] PS_ON: Power-on signal

[0032] PGO: Operational Signal

[0033] PW OK: Power is normal signal

[0034] 40: AC power supply

[0035] 41: Load Detailed Implementation

[0036] The terms "first" and "second" used in this article are used to distinguish components with the same name, not to restrict the order of events.

[0037] The detailed description and technical content of this utility model are now explained in conjunction with the accompanying drawings:

[0038] Please see Figure 1 This invention provides a switching power supply architecture 20, which aims to solve the problem that conventional architectures generate concentrated waste heat on some main circuits during operation, requiring a cooling fan. This switching power supply architecture 20 can be used in a power supply designed according to the ATX standard or a fanless power supply. The switching power supply architecture 20 connects to an AC power source 40, converts the AC power 40, and supplies power to at least one load 41. The switching power supply architecture 20 has an output power. The AC power supply architecture 20 includes a power factor correction circuit 21, an LLC resonant converter circuit 22, and a wide input range buck circuit 23.

[0039] The power factor correction circuit 21 is connected to the AC power supply 40 and serves as the power input terminal of the switching power supply architecture 20. The power factor correction circuit 21 adjusts a first output voltage 211 supplied to the subsequent stage based on the output power. More specifically, the power factor correction circuit 21 changes its operation according to the current output state of the switching power supply architecture 20 to adjust the first output voltage 211 supplied to the subsequent stage. In one embodiment, the power factor correction circuit 21 has a light-load output mode and a heavy-load output mode. The power factor correction circuit 21 operates in the light-load output mode and the heavy-load output mode based on the output power compared to a comparison value. The aforementioned comparison value may be based on a rated power of the AC power supply architecture 20; for example, the comparison value may be 60% of the rated power. When the current output power of the switching power supply architecture 20 is less than 60% of its rated power, it can be considered that the switching power supply architecture 20 is in a light-load state, and the power factor correction circuit 21 operates in the light-load output mode. Conversely, when the current output power of the switching power supply architecture 20 is less than 60% of its rated power, it can be considered that the switching power supply architecture 20 is in a heavy-load state, and the power factor correction circuit 21 operates in the heavy-load output mode. In the light-load output mode, the power factor correction circuit 21 makes the first output voltage 211 greater than the peak value of an input voltage provided by the AC power supply 40. The aforementioned "greater than" does not mean excessive increase, but only appropriately increases the voltage value of the first output voltage 211. For example, in the light-load output mode, the voltage value of the first output voltage 211 will be 7 to 10 volts greater than the peak value of the input voltage. This effectively adjusts the power factor and improves the conversion efficiency, thereby reducing losses and overall heat generation. On the other hand, in the heavy-load output mode, the power factor correction circuit 21 adjusts the first output voltage 211 based on the output power. In this mode, the power factor correction circuit 21 needs to ensure that the switching power supply architecture 20 still has the output hold-up time specified in the ATX specification. Continuing above, in one embodiment, the first output voltage 211 of the power factor correction circuit 21 ranges from 130 volts to 420 volts.

[0040] Furthermore, the LLC resonant converter circuit 22 of this invention is the stage following the power factor correction circuit 21 and receives the first output voltage 211. The LLC resonant converter circuit 22 provides a second output voltage 221 to the stage following it. The LLC resonant converter circuit 22 of this invention is open-loop controlled, that is, the LLC resonant converter circuit 22 does not perform feedback control. In other words, the control of the LLC resonant converter circuit 22 is independent of the load and the first output voltage 211 (i.e., the input voltage of the LLC resonant converter circuit 22). The LLC resonant converter circuit 22 maintains operation at the series resonant frequency point to maintain the provision of the second output voltage 221 in full resonant mode. Further, the LLC resonant converter circuit 22 of this invention operates in zero-voltage switching mode under full load, and the output voltage (i.e., the second output voltage 221) of the LLC resonant converter circuit 22 is different from the conventional fixed value, and has a wider output range. In one embodiment, the second output voltage 221 of the LLC resonant converter circuit 22 is 13 to 60 volts. Compared to conventional circuits, the LLC resonant converter circuit 22 of this invention reduces the output current supplied to subsequent stages, thereby reducing losses and heat generation. In one embodiment, the turns ratio of the LLC resonant converter circuit 22 is 7. Furthermore, the turns ratio of the LLC resonant converter circuit 22 can be adjusted according to the efficiency distribution of the overall architecture.

[0041] Continuing from the above, the wide input range buck circuit 23 is the subsequent stage of the LLC resonant converter circuit 22. The wide input range buck circuit 23 receives the second output voltage 221 and is connected to the at least one load 41. The wide input range buck circuit 23 of this invention can be an interleaved buck converter, a switched capacitor converter, a dual phase 3-level buck converter, or a regulated hybrid switched capacitor converter. The wide input range buck circuit 23 supplies 12 volts of power to the at least one load 41. The wide input range buck circuit 23 can be combined with various buck circuits according to output voltage requirements to achieve a buck ratio of 2:1, 4:1, or 8:1. The output voltage of the wide input range buck circuit 23 of this invention can be DC power from 3.3 volts to 12 volts.

[0042] This utility model's switching power supply architecture 20 achieves heat dissipation by distributing losses across various circuit stages, thus avoiding excessive losses on certain circuits. Furthermore, this utility model's switching power supply architecture 20 does not include a cooling fan for at least cooling the LLC resonant converter circuit 22 and the wide input range buck circuit 23. In addition, the LLC resonant converter circuit 22 in this utility model's switching power supply architecture 20 employs open-loop control and operates in full resonant mode, simplifying the control of the LLC resonant converter circuit 22 compared to conventional methods. Moreover, this utility model's switching power supply architecture 20 effectively reduces losses and improves the overall efficiency of the switching power supply architecture 20.

[0043] Please see Figure 2 and Figure 3 In one embodiment, the switching power supply architecture 20 includes a flyback converter circuit 24, a transformer 25, and an auxiliary power output circuit 26. The flyback converter circuit 24 serves as the stage following the power factor correction circuit 21 and receives the first output voltage 211. The transformer 25 is connected to the flyback converter circuit 24. The auxiliary power output circuit 26 serves as the stage following the transformer 25 and provides a standby power supply to the aforementioned flyback converter circuit 24. This standby power supply is what those skilled in the art typically describe as standby power. This standby power supply can be 5 volts or 12 volts.

[0044] Please refer to the following: Figure 3 In one embodiment, the switching power supply architecture 20 includes a secondary power conversion circuit 27. This secondary power conversion circuit 27 serves as a downstream stage of the wide input range buck circuit 23. The secondary power conversion circuit 27 receives power from the wide input range buck circuit 23 and performs further power conversion (e.g., step-down), providing at least one third output voltage. In this embodiment, the switching power supply architecture 20 can provide multiple voltages required for ATX specifications through the wide input range buck circuit 23 and the secondary power conversion circuit 27. For example, the wide input range buck circuit 23 provides a +12V voltage, while the secondary power conversion circuit 27 can output 3.3V and 5V voltages. In one embodiment, the secondary power conversion circuit 27 can also output a -12V voltage.

[0045] Please refer to the following: Figure 2In one embodiment, the switching power supply architecture 20 includes a first management circuit 28, a second management circuit 29, and a signal isolator 30. The first management circuit 28 serves as an auxiliary circuit to the LLC resonant converter circuit 22, and the second management circuit 29 serves as an auxiliary circuit to the power factor correction circuit 21. The signal isolator 30 connects the first management circuit 28 and the second management circuit 29, allowing them to transmit signals. When the first management circuit 28 receives a power-on signal (PS_ON) from the at least one load 41, it sends a status confirmation signal to the second management circuit 29 via the signal isolator 30. The second management circuit 29 then generates an operational signal (PGO) based on the operating state of the power factor correction circuit 21, and this operational signal (PGO) is transmitted to the first management circuit 28 via the signal isolator 30. The first management circuit 28 then provides a power-normal signal (PW OK) to the at least one load 41. In addition, the first management circuit 28 and the second management circuit 29 are used to activate the LLC resonant converter circuit 22 and the power factor correction circuit 21, respectively. The first management circuit 28 can be implemented by an analog integrated circuit or a digital integrated circuit, as can the second management circuit 29.

Claims

1. A switching power supply architecture, connected to an AC power source and supplying power to at least one load, the switching power supply architecture having an output power, characterized in that, This switching power supply architecture includes: A power factor correction circuit is connected to the AC power supply. The power factor correction circuit adjusts a first output voltage supplied to the subsequent stage based on the output power. An LLC resonant converter circuit serves as the downstream stage of the power factor correction circuit and receives the first output voltage. This LLC resonant converter circuit provides a second output voltage to the downstream stage. The LLC resonant converter circuit is open-loop controlled and operates at its series resonant frequency to maintain the second output voltage in full resonant mode. A wide input range buck converter is provided as the stage following the LLC resonant converter circuit and receives the second output voltage. The wide input range buck converter is connected to the at least one load.

2. The switching power supply architecture as described in claim 1, characterized in that, The power factor correction circuit has a light-load output mode and a heavy-load output mode. The power factor correction circuit operates in the light-load output mode or the heavy-load output mode based on the output power compared to a comparison value. In the light-load output mode, the power factor correction circuit makes the first output voltage greater than the peak value of an input voltage provided by the AC power supply. In the heavy-load output mode, the power factor correction circuit adjusts the first output voltage based on the output power.

3. The switching power supply architecture as described in claim 1, characterized in that, The switching power supply architecture includes a flyback converter circuit that serves as the stage after the power factor correction circuit and receives the first output voltage, a transformer connected to the flyback converter circuit, and an auxiliary power output circuit that serves as the stage after the transformer and provides a standby power.

4. The switching power supply architecture as described in claim 1, characterized in that, The switching power supply architecture includes a secondary power conversion circuit as a stage following the wide input range buck circuit, which provides at least a third output voltage.

5. The switching power supply architecture as described in any one of claims 1 to 4, characterized in that, The switching power supply architecture includes a first management circuit as an auxiliary circuit of the LLC resonant converter circuit, a second management circuit as an auxiliary circuit of the power factor correction circuit, and a signal isolator connecting the first management circuit and the second management circuit. The first management circuit can receive a power-on signal from the at least one load. The first management circuit and the second management circuit can transmit signals through the signal isolator. The first management circuit provides a power-normal signal to the at least one load.

6. The switching power supply architecture as described in claim 5, characterized in that, The switching power supply architecture does not include a cooling fan for at least the LLC resonant converter circuit and the wide input range buck circuit.

7. The switching power supply architecture as described in any one of claims 1 to 4, characterized in that, The first output voltage ranges from 130 volts to 420 volts, and the second output voltage ranges from 13 volts to 60 volts.

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