CN-115296529-B - DC-DC power conversion system and power conversion method thereof

Abstract

The DC-DC power conversion system comprises a resonant switching capacitor converter and a controller. The resonant switching capacitor converter receives an input voltage and switches between a first state and a second state to generate an output voltage. The resonant switching type capacitance converter comprises an input end, a resonant tank, an output capacitance, a first group of switches and a second group of switches. The input terminal receives an input voltage. The output capacitor generates an output voltage. The first group of switches are coupled to the resonant tank and the output capacitor, receive the first control signal to be turned on in the first state and turned off in the second state. The second group of switches are coupled to the resonant tank and the output capacitor, receive a second control signal to be turned on in a second state and turned off in a first state. The controller adjusts the first control signal and the second control signal according to the output voltage.

Inventors

• LIU GUOJI
• YANG DAYONG
• BAI ZHONGLONG

Assignees

• 立锜科技股份有限公司

Dates

Publication Date

20260505

Application Date

20210929

Priority Date

20210908

Claims (19)

1. 1. A dc-dc power conversion system comprising: An input terminal for receiving an input voltage; a resonant switched capacitor converter for receiving the input voltage and switching between a first state and a second state to generate an output voltage, the resonant switched capacitor converter comprising: A first resonant tank; The output capacitor is provided with a first end and a second end, wherein the first end is used for generating the output voltage; a first set of switches coupled to the first resonant tank and the output capacitor for receiving a first control signal to turn on in the first state and turn off in the second state, and The second group of switches are coupled with the first resonant tank and the output capacitor and are used for receiving a second control signal to be turned on in the second state and turned off in the first state; an output terminal coupled to the output capacitor for outputting the output voltage, and The controller is coupled to the first group of switches and the second group of switches, and is used for adjusting the first control signal according to the output voltage to control the first conduction time of the first group of switches and adjusting the second control signal according to the output voltage to control the second conduction time of the second group of switches; Wherein the controller comprises: the voltage divider is coupled to the first end of the output capacitor and used for generating the divided voltage of the output voltage; the first comparison circuit is coupled to the voltage divider and used for comparing the divided voltage with a reference voltage to generate a first comparison voltage; the second comparison circuit is coupled to the first comparison circuit and is used for comparing the first comparison voltage with the slope voltage to generate a second comparison voltage; The first AND gate is coupled to the second comparison circuit and used for performing AND operation on the second comparison voltage and the clock signal to generate a control signal; the trigger is coupled to the first AND gate and used for generating an output signal and a reverse output signal according to the control signal; a second AND gate coupled to the flip-flop for performing an AND operation on the control signal and the output signal to generate the first control signal, and And the third AND gate is coupled with the trigger and used for performing AND operation on the control signal and the reverse output signal to generate the second control signal.
2. 2. The dc-dc power conversion system of claim 1, wherein in the first state, the first set of switches is configured to connect the first resonant tank in series between the input terminal and the output capacitor.
3. 3. The dc-dc power conversion system of claim 1, wherein in the second state, the second set of switches is configured to connect the first resonant tank and the output capacitor in parallel.
4. 4. The dc-dc power conversion system of claim 1, wherein the controller is configured to alternately switch the resonant switching capacitor converter between the first state and the second state.
5. 5. The dc-dc power conversion system of claim 1, wherein the first on-time is less than a first off-time of the first set of switches and the second on-time is less than a second off-time of the second set of switches.
6. 6. The dc-dc power conversion system of claim 1, wherein a length of the first on-time is equal to a length of the second on-time.
7. 7. The dc-dc power conversion system of claim 1, wherein The first resonant tank includes: A first resonant capacitor having a first end and a second end, and The first resonant inductor is provided with a first end and a second end, and is coupled with the first end of the output capacitor; The resonant switching type capacitive converter further comprises a second resonant tank, comprising: a second resonance capacitor having a first end and a second end, and The second resonance inductor is provided with a first end and a second end, and is coupled with the first end of the output capacitor; The first set of switches comprises: The first transistor is provided with a first end, a second end, a control end and a first control signal, wherein the second end is coupled with the first end of the first resonant capacitor; the second transistor is provided with a first end, a second end and a control end, wherein the first end is coupled with the second end of the first resonant capacitor; A third transistor having a first end coupled to the first end of the second resonant inductor, a second end coupled to the first end of the second resonant capacitor, and a control end for receiving the first control signal A fourth transistor having a first end coupled to the second end of the second resonant capacitor, a second end coupled to the ground, and a control end for receiving the first control signal, and The second set of switches comprises: the first transistor is provided with a first end, a second end and a control end, wherein the first end is coupled with the first end of the first resonant inductor; a sixth transistor having a first terminal coupled to the second terminal of the first resonant capacitor; the second end is coupled to the grounding end, and the control end is used for receiving the second control signal; a seventh transistor having a first end coupled to the first end of the second resonance capacitor, a second end, and a control end for receiving the second control signal, and The eighth transistor has a first end coupled to the second end of the second resonant capacitor, a second end coupled to the first end of the second resonant inductor, and a control end for receiving the second control signal.
8. 8. The dc-dc power conversion system of claim 1, wherein The first resonant tank includes: A first resonant capacitor having a first end and a second end, and The first resonant inductor is provided with a first end, a second end and a third end, wherein the second end is coupled with the first resonant capacitor; The resonant switching type capacitive converter further comprises a second resonant tank, comprising: a second resonance capacitor having a first end and a second end, and The second resonance inductor is provided with a first end, a second end and a third end, wherein the second end is coupled with the second end of the second resonance capacitor; The first set of switches comprises: The first transistor is provided with a first end, a second end, a control end and a first control signal, wherein the second end is coupled with the first end of the first resonant capacitor; the second transistor is provided with a first end, a second end and a control end, wherein the first end is coupled with the second end of the first resonant inductor; a third transistor having a first end coupled to the first end of the output capacitor, a second end coupled to the first end of the second resonance capacitor, and a control end for receiving the first control signal A fourth transistor having a first end coupled to the second end of the second resonant inductor, a second end coupled to the ground end, and a control end for receiving the first control signal, and The second set of switches comprises: the first transistor is provided with a first end, a second end and a control end, wherein the first end is coupled with the first end of the output capacitor; a sixth transistor having a first terminal coupled to the second terminal of the first resonant inductor; the second end is coupled to the grounding end, and the control end is used for receiving the second control signal; a seventh transistor having a first end coupled to the first end of the second resonance capacitor, a second end, and a control end for receiving the second control signal, and The eighth transistor has a first end coupled to the second end of the second resonant inductor, a second end coupled to the first end of the output capacitor, and a control end for receiving the second control signal.
9. 9. The dc-dc power conversion system of claim 1, wherein The first resonant tank includes: A first resonant capacitor having a first end and a second end, and The first resonant inductor is provided with a first end, a second end and a third end, wherein the second end is coupled with the first resonant capacitor; The resonant switching capacitor converter further comprises a storage capacitor, a first capacitor and a second capacitor, wherein the storage capacitor is provided with a first end and a second end; The first set of switches comprises: The first transistor is provided with a first end, a second end and a control end, wherein the first end is coupled with the first end of the storage capacitor; a second transistor having a first end coupled to the second end of the first resonant inductor, a second end coupled to the first end of the output capacitor, and a control end for receiving the first control signal, and A third transistor having a first end coupled to the second end of the storage capacitor, a second end coupled to the ground, and a control end for receiving the first control signal The second set of switches comprises: The first transistor is provided with a first end, a second end and a control end, wherein the first end is coupled with the first end of the first resonant capacitor; a sixth transistor having a first terminal coupled to the second terminal of the first resonant inductor; the second end is coupled to the grounding end, and the control end is used for receiving the second control signal; A seventh transistor having a first end, a second end coupled to the first end of the storage capacitor, and a control end for receiving the second control signal, and The eighth transistor has a first end coupled to the second end of the storage capacitor, a second end coupled to the first end of the output capacitor, and a control end for receiving the second control signal.
10. 10. The dc-dc power conversion system of claim 1, wherein The first resonant tank includes: A first resonant capacitor having a first end and a second end, and The first resonant inductor is provided with a first end and a second end, and is coupled with the first end of the output capacitor; The resonant switching type capacitance converter further comprises: a second resonance capacitor having a first end and a second end, and The second resonance inductor is provided with a first end and a second end, and is coupled with the first end of the output capacitor; The first set of switches comprises: the second transistor is provided with a first end, a second end and a control end, wherein the first end is coupled with the first end of the first resonant capacitor; A third transistor having a first end coupled to the second end of the first resonant capacitor, a second end coupled to the first end of the first resonant inductor, and a control end for receiving the first control signal A fourth transistor having a first end, a second end coupled to the first end of the second resonant capacitor, and a control end for receiving the first control signal, and The second set of switches comprises: the second end is coupled with the first end of the first resonance capacitor, and the control end is used for receiving the second control signal; a sixth transistor having a first terminal coupled to the second terminal of the first resonant capacitor; the second end is coupled to the grounding end, and the control end is used for receiving the second control signal; A seventh transistor having a first end coupled to the first end of the second resonant inductor, a second end coupled to the first end of the second resonant capacitor, and a control end for receiving the second control signal, and The eighth transistor has a first end coupled to the second end of the second resonance capacitor, a second end coupled to the ground end, and a control end for receiving the second control signal.
11. 11. The dc-dc power conversion system of claim 1, wherein a ratio of the input voltage to the output voltage is greater than 2 to 1.
12. 12. The dc-dc power conversion system of claim 1, wherein the first on-time and the second on-time are equal to a predetermined on-time that is substantially less than 50% of a duty cycle at power-on.
13. 13. A power conversion method is applicable to a DC-DC power conversion system, the DC-DC power conversion system comprises a resonant switching type capacitance converter and a controller, the resonant switching type capacitance converter comprises an input end, a first resonant tank, an output capacitance, a first group of switches, a second group of switches and a third group of switches, wherein the first group of switches and the third group of switches are coupled with the first resonant tank and the output capacitance, and the method comprises the following steps: the resonant switching type capacitance converter is switched between a first state and a second state to generate an output voltage; The controller adjusts the first control signal and the second control signal according to the output voltage; the first switch receives the first control signal to conduct the first conduction time in the first state and The second group of switches receives the second control signal and conducts a second conduction time when the second control signal is in the second state; Wherein the controller comprises: the voltage divider is coupled to the first end of the output capacitor and used for generating the divided voltage of the output voltage; the first comparison circuit is coupled to the voltage divider and used for comparing the divided voltage with a reference voltage to generate a first comparison voltage; the second comparison circuit is coupled to the first comparison circuit and is used for comparing the first comparison voltage with the slope voltage to generate a second comparison voltage; The first AND gate is coupled to the second comparison circuit and used for performing AND operation on the second comparison voltage and the clock signal to generate a control signal; the trigger is coupled to the first AND gate and used for generating an output signal and a reverse output signal according to the control signal; a second AND gate coupled to the flip-flop for performing an AND operation on the control signal and the output signal to generate the first control signal, and And the third AND gate is coupled with the trigger and used for performing AND operation on the control signal and the reverse output signal to generate the second control signal.
14. 14. The method of claim 13, wherein in the first state, the first set of switches connects the first resonant tank in series between the input terminal and the output capacitor.
15. 15. The method of claim 13, wherein in the second state, the second set of switches connects the first resonant tank and the output capacitor in parallel.
16. 16. The method of claim 13, wherein the controller alternately switches the resonant switched capacitor converter between the first state and the second state.
17. 17. The method according to claim 13, wherein: the first group of switches receives the first control signal to cut off a first cut-off time; the second switch receives the second control signal to cut off the second cut-off time, and The first on-time is less than the first off-time, and the second on-time is less than the second off-time.
18. 18. The method of claim 13, wherein the length of the first on-time is equal to the length of the second on-time.
19. 19. The method of claim 13, wherein at power-on, the first on-time and the second on-time are equal to a predetermined on-time that is substantially less than 50% of a duty cycle.

Description

DC-DC power conversion system and power conversion method thereof Technical Field The present invention relates to electronic circuits, and more particularly, to a dc-dc power conversion system and a power conversion method thereof. Background The dc-dc converter is a device for converting dc voltage into different dc voltages, and is commonly used in mobile electronic devices such as mobile phones and notebook computers to provide power. The resonant switched capacitor converter (resonant switched-capacitor converter, RSCC) is a dc-dc converter that generates no or only a small amount of power consumption when transmitting power. The resonant switching capacitor converter converts the input voltage into the output voltage at a fixed conversion ratio. When the input voltage is too large, the resonant switching capacitor converter still generates an excessive output voltage with a fixed conversion ratio, which causes damage to the electronic device. The related art controls the input voltage of the resonant switching capacitor converter by using an additional buck converter (bulk converter) to control the output voltage of the resonant switching capacitor converter. However, buck converters occupy a large amount of circuit area, resulting in increased manufacturing costs. Disclosure of Invention The embodiment of the invention provides a direct current-direct current power conversion system which comprises a resonant switching type capacitance converter and a controller. The resonant switching type capacitive converter is used for receiving an input voltage and switching between a first state and a second state to generate an output voltage. The resonant switching type capacitance converter comprises an input end, a resonant tank, an output capacitance, a first group of switches and a second group of switches. The input terminal is used for receiving an input voltage. The output capacitor has a first end for generating an output voltage, and a second end coupled to the ground. The first group of switches are coupled to the resonant tank and the output capacitor and are used for receiving a first control signal to be turned on in a first state and turned off in a second state. The second group of switches is coupled to the resonant tank and the output capacitor and is used for receiving a second control signal to be turned on in a second state and turned off in a first state. The output end is coupled to the output capacitor and is used for outputting output voltage. The controller is coupled to the first set of switches and the second set of switches, and is configured to adjust the first control signal according to the output voltage to control a first on time of the first set of switches, and adjust the second control signal according to the output voltage to control a second on time of the second set of switches. The embodiment of the invention provides another power conversion method which is suitable for a direct current-direct current power conversion system. The DC-DC power conversion system comprises a resonant switching type capacitance converter and a controller, wherein the resonant switching type capacitance converter comprises a resonant tank, an output capacitor, a first group of switches, a second group of switches and a third group of switches, wherein the first group of switches and the second group of switches are coupled with the resonant tank and the output capacitor. The power conversion method comprises the steps that the resonance switching type capacitance converter is switched between a first state and a second state to generate output voltage, the controller adjusts the first control signal and the second control signal according to the output voltage, the first group of switches receive the first control signal to conduct first conduction time in the first state, and the second group of switches receive the second control signal to conduct second conduction time in the second state. Drawings Fig. 1 is a block diagram of a dc-dc power conversion system in accordance with an embodiment of the present invention. Fig. 2 is a circuit schematic of a dc-dc power conversion system of fig. 1. Fig. 3 is a flow chart of a power conversion method of the dc-dc power conversion system of fig. 1. Fig. 4 is a circuit schematic of the controller of fig. 1. Fig. 5 is a waveform diagram of the controller of fig. 4. Fig. 6 is a simulated waveform diagram of the dc-dc power conversion system of fig. 1 when the first control signal Sc1 and the second control signal Sc2 are both substantially 50% duty cycle. Fig. 7 is a simulated waveform diagram of the dc-dc power conversion system of fig. 1 when the first control signal Sc1 and the second control signal Sc2 are both substantially 25% duty cycle. Fig. 8 is a circuit schematic of another resonant switched capacitor converter of fig. 1. Fig. 9 is a circuit schematic of another resonant switched capacitor converter of fig. 1. Fig. 10 is a circuit schematic