TWI851348B - Power supply device - Google Patents

Abstract

A power supply device includes a rectifier module, a booster module, a first switch module, a second switch module, a detecting module, a logic module and a control module. The rectifier module converts an AC voltage into a DC voltage. The booster module receives the DC voltage, and generates a booster voltage. The first and second switch modules determine whether to conduct according to first and second control signals. The detecting module generates a first detecting signal according to a first conduction number of the first switch module and a predetermined conduction number, and generates a second detecting signal according to a second conduction number of the second switch module and the predetermined conduction number. The logic module generates a first logic signal and a second logic signal according to the first detecting signal, the second detecting signal and a reference voltage. The control module generates first and second control signals according to the first and second logic signals.

Description

Power supply device

The present invention relates to a power supply device, and more particularly to a power supply device with improved boost conversion ratio and power factor.

Generally speaking, the power supply will operate the boost inductor current of the boost power factor corrector in continuous current mode to provide more energy. In addition, in order to achieve miniaturization of the charger, the power switch is designed to switch at a high switching frequency. However, at a high switching frequency, the power switch reaction speed cannot keep up with the continuous current, resulting in abnormal boost inductor current and leaving the continuous mode, causing abnormal boost conversion or output voltage oscillation. Therefore, how to effectively improve the boost conversion abnormality or output voltage oscillation and increase the convenience of use is an important issue at present.

The present invention provides a power supply device, which can effectively improve the boost conversion ratio and power factor and increase the convenience of use.

The present invention provides a power supply device, including a rectifier module, a boost module, a first switch module, a second switch module, a detection module, a logic module and a control module. The rectifier module receives an AC voltage and converts the AC voltage into a DC voltage. The boost module is coupled to the rectifier module, receives a DC voltage, and generates a boost voltage. The first switch module is coupled to the boost module, and determines whether to conduct according to a first control signal. The second switch module is coupled to the boost module, and determines whether to conduct according to a second control signal. The detection module is coupled to the first switch module and the second switch module, detects a first conduction number of the first switch module, and generates a first detection signal according to the first conduction number and a preset conduction number, and detects a second conduction number of the second switch module, and generates a second detection signal according to the second conduction number and the preset conduction number. The logic module is coupled to the detection module, generates a first logic signal according to the first detection signal and a reference voltage, and generates a second logic signal according to the second detection signal and a reference voltage. The control module is coupled to the first switch module, the second switch module and the logic module, receives the first logic signal and the second logic signal, generates a first control signal according to the first logic signal, and generates a second control signal according to the second logic signal.

The voltage supply device disclosed in the present invention detects the first conduction number of the first switch module through the detection module, and generates a first detection signal according to the first conduction number and the preset conduction number, and detects the second conduction number of the second switch module, and generates a second detection signal according to the second conduction number and the preset conduction number. The logic module generates a first logic signal according to the first detection signal and a reference voltage, and generates a second logic signal according to the second detection signal and the reference voltage. The control module generates a first control signal according to the first logic signal, and generates a second control signal according to the second logic signal, so as to intermittently control the first switch module and the second switch module to perform switching operations. In this way, the boost conversion ratio and power factor can be effectively improved, and the convenience of use can be increased.

It must be understood that the words "comprise", "include" and the like used in this specification are used to indicate the existence of specific technical features, numerical values, method steps, operation processes, elements and/or components, but do not exclude the addition of more technical features, numerical values, method steps, operation processes, elements, components, or any combination thereof.

The terms "first", "second", etc. are used to modify components and are not used to indicate a priority or precedence relationship between them. They are only used to distinguish components with the same name.

In the various embodiments listed below, the same reference numerals will be used to represent the same or similar elements or components.

FIG. 1 is a schematic diagram of a power supply device according to an embodiment of the present invention. Referring to FIG. 1 , the power supply device 100 includes a rectifier module 110 , a voltage conversion module 120 , a first switch module 130 , a second switch module 140 , a detection module 150 , a logic module 160 and a control module 170 .

The rectifier module 110 receives the AC voltage VAC and converts the AC voltage VAC into a DC voltage VDC. In the present embodiment, the rectifier module 110 may include a bridge rectifier, such as a full-bridge rectifier, but the present embodiment is not limited thereto. The boost module 120 is coupled to the rectifier module 110. The voltage conversion module 120 receives the DC voltage VDC to generate a boost voltage VB.

The first switch module 130 is coupled to the boost module 120. The first switch module 130 determines whether to conduct according to the first control signal CS1. In the present embodiment, the first control signal CS1 may be a pulse width modulation signal, but the present embodiment is not limited thereto. For example, when the first control signal CS1 is, for example, a high logic level, the first switch module 130 is conducted. When the first control signal CS1 is, for example, a low logic level, the first switch module 130 is not conducted.

The second switch module 140 is coupled to the boost module 120. The second switch module 140 determines whether to conduct according to the second control signal CS2. In the present embodiment, the second control signal CS2 may be a pulse width modulation signal, but the present embodiment is not limited thereto. For example, when the second control signal CS2 is, for example, a high logic level, the second switch module 140 is conducted. When the second control signal CS2 is, for example, a low logic level, the second switch module 140 is not conducted.

The detection module 150 couples the first switch module 130 and the second switch module 140. The detection module 150 detects the first conduction number of the first switch module 130, and generates a first detection signal DS1 according to the first conduction number and the preset conduction number. In other words, the detection module 150 detects the first conduction number of the first switch module 130 and counts the first conduction number. Then, the detection module 150 can compare the first conduction number with the preset conduction number to determine whether the first conduction number is the same as the preset conduction number, so as to generate the first detection signal DS1.

For example, when the detection module 150 determines that the first conduction number is not the same as the preset conduction number, the detection module 150 generates a first detection signal DS1, such as a first voltage level. When the detection module 150 determines that the first conduction number is the same as the preset conduction number, the detection module 150 generates a first detection signal DS1, such as a second voltage level. In this embodiment, the first voltage level is, for example, a high voltage level, and the second voltage level is, for example, a low voltage level, but the embodiments of the present invention are not limited thereto.

In addition, the detection module 150 detects the second conduction times of the second switch module 140, and generates a second detection signal DS2 according to the second conduction times and the preset conduction times. In other words, the detection module 150 detects the second conduction times of the second switch module 140, and counts the second conduction times. Then, the detection module 150 can compare the second conduction times with the preset conduction times to determine whether the second conduction times are the same as the preset conduction times, so as to generate the second detection signal DS2.

For example, when the detection module 150 determines that the second conduction number is not the same as the preset conduction number, the detection module 150 generates a second detection signal DS2 such as a first voltage level. When the detection module 150 determines that the second conduction number is the same as the preset conduction number, the detection module 150 generates a second detection signal DS2 such as a second voltage level.

In this embodiment, the first detection signal DS1 and the second detection signal DS2 are complementary. For example, when the detection module 150 generates the first detection signal DS1, such as a first voltage level, the detection module 150 generates the second detection signal DS2, such as a second voltage level. For example, when the detection module 150 generates the first detection signal DS1, such as a second voltage level, the detection module 150 generates the second detection signal DS2, such as a first voltage level.

In some embodiments, the preset conduction times are, for example, associated with the switching frequency of the first switch module 130 and the second switch module 140. For example, when the switching frequency of the first switch module 130 and the second switch module 140 is higher, the preset conduction times are lower. When the switching frequency of the first switch module 130 and the second switch module 140 is lower, the preset conduction times are higher. In this embodiment, assuming that the switching frequency of the first switch module 130 and the second switch module 140 is 250KHz, the preset conduction times are 2 times, but the embodiments of the present invention are not limited thereto.

The logic module 160 is coupled to the detection module 150. The logic module 160 receives the first detection signal DS1, the second detection signal DS2 and the reference voltage VF. The logic module 160 generates the first logic signal LS1 according to the first detection signal DS1 and the reference voltage VF. In the present embodiment, the reference voltage VF is, for example, a voltage of a high voltage level, but the embodiments of the present invention are not limited thereto. In addition, the reference voltage VF can be provided by the control module 170 or other reference voltage generating circuits (not shown).

Furthermore, the logic module 160 may perform an AND operation on the first detection signal DS1 and the reference voltage VF to generate a first logic signal LS1. For example, when the first detection signal DS1 and the reference voltage VF are both at a high voltage level, the logic module 160 generates the first logic signal LS1, for example, at a first logic level. When the first detection signal DS1 is at a low voltage level and the reference voltage VF is at a high voltage level, the logic module 160 generates the first logic signal LS1, for example, at a second logic level. In this embodiment, the first logic level is, for example, a high logic level, and the second logic level is, for example, a low logic level, but the embodiment of the present invention is not limited thereto.

In addition, the logic module 160 generates a second logic signal LS2 according to the second detection signal DS2 and the reference voltage VF. Further, the logic module 160 can perform an AND operation on the second detection signal DS2 and the reference voltage VF to generate the second logic signal LS2. For example, when the second detection signal DS2 and the reference voltage VF are both at a high voltage level, the logic module 160 generates a second logic signal LS2 at, for example, a first logic level. When the second detection signal DS2 is at a low voltage level and the reference voltage VF is at a high voltage level, the logic module 160 generates a second logic signal LS2 of, for example, a second logic level.

The control module 170 couples the first switch module 130, the second switch module 140 and the logic module 160. The control module 170 receives the first logic signal LS1 and the second logic signal LS2. The control module 170 generates the first control signal CS1 according to the first logic signal LS1. For example, when the first logic signal LS1 is at a high logic level, the control module 170 generates the first control signal CS1 so that the first switch module 130 can perform a switching operation between conduction and non-conduction according to the first control signal CS1. When the first logic signal LS1 is at a low logic level, the control module 170 does not generate the first control signal CS1, and the first switch module 130 does not operate.

In addition, the control module 170 generates a second control signal CS2 according to the second logic signal LS2. For example, when the second logic signal LS2 is at a high logic level, the control module 170 generates the second control signal CS2, so that the second switch module 140 can perform a switching operation between conducting and non-conducting according to the second control signal CS2. When the second logic signal LS2 is at a low logic level, the control module 170 does not generate the second control signal CS2, and the second switch module 140 does not operate.

In this way, the power supply device 100 of the present embodiment intermittently controls the first switch module 130 and the second switch module 140 through the detection module 150, the logic module 160 and the control module 170, so that the first switch module 130 and the second switch module 140 perform intermittent switching operations to effectively improve the boost conversion ratio and power factor and increase the convenience of use.

In some embodiments, the power supply device 100 further includes an output module 180. The output module 180 is coupled to the boost module 120. The output module 180 receives the boost voltage VB to generate an output voltage VO.

Figure 2 is a detailed schematic diagram of a power supply device according to an embodiment of the present invention. Referring to Figure 2, the rectifier module 110 includes rectifier diodes D1, D2, D3 and D4. The rectifier diode D1 has a first end (e.g., an anode end) and a second end (e.g., a cathode end). The first end of the rectifier diode D1 is coupled to the first end of the AC power source 210 and receives the AC voltage VAC. The second end of the rectifier diode D1 generates a DC voltage VDC. The rectifier diode D2 has a first end (e.g., an anode end) and a second end (e.g., a cathode end). The first end of the rectifier diode D2 is coupled to the second end of the AC power source 210. The second end of the rectifier diode D2 is coupled to the second end of the rectifier diode D1.

The rectifier diode D3 has a first end (e.g., an anode end) and a second end (e.g., a cathode end). The first end of the rectifier diode D3 is coupled to the ground end GND. The second end of the rectifier diode D3 is coupled to the first end of the rectifier diode D1. The rectifier diode D4 has a first end (e.g., an anode end) and a second end (e.g., a cathode end). The first end of the rectifier diode D4 is coupled to the ground end GND. The second end of the rectifier diode D4 is coupled to the first end of the rectifier diode D2.

The boost module 120 includes a boost inductor LM. The boost inductor LM has a first end and a second end. The first end of the boost inductor LM receives a DC voltage VDC. The second end of the boost inductor LM generates a boost voltage VB and a boost inductor current ILM.

The first switch module 130 includes a first power switch QX1. The first power switch QX1 has a first end, a second end, and a control end. The first end of the first power switch QX1 is coupled to the boost module 120 (i.e., the second end of the boost inductor LM) and the detection module 150. The second end of the first power switch QX1 is coupled to the ground end GND. The control end of the first power switch QX1 is coupled to the control module 170 and receives the first control signal CS1. Further, the first power switch QX1 can determine whether to conduct according to the voltage level of the first control signal CS1.

For example, when the control end of the first power switch QX1 receives the first control signal CS1 of, for example, a high voltage level, the first power switch QX1 is turned on. When the control end of the first power switch QX1 receives the first control signal CS1 of, for example, a low voltage level, the first power switch QX1 is not turned on. In the present embodiment, the first power switch QX1 is, for example, an N-type transistor, wherein the first end of the first power switch QX1 is, for example, a drain end of the N-type transistor, the second end of the first power switch QX1 is, for example, a source end of the N-type transistor, and the control end of the first power switch QX1 is, for example, a gate end of the N-type transistor, but the present embodiment is not limited thereto. In some embodiments, the first power switch QX1 may also be a P-type transistor or other suitable transistors.

The second switch module 140 includes a second power switch QX2. The second power switch QX2 has a first end, a second end, and a control end. The first end of the second power switch QX2 is coupled to the boost module 120 (i.e., the second end of the boost inductor LM) and the detection module 150. The second end of the second power switch QX2 is coupled to the ground end GND. The control end of the second power switch QX2 is coupled to the control module 170 and receives the second control signal CS2. Further, the second power switch QX2 can determine whether to conduct according to the voltage level of the second control signal CS2.

For example, when the control end of the second power switch QX2 receives the second control signal CS2 of, for example, a high voltage level, the second power switch QX2 is turned on. When the control end of the second power switch QX2 receives the second control signal CS2 of, for example, a low voltage level, the second power switch QX2 is not turned on. In the present embodiment, the second power switch QX2 is, for example, an N-type transistor, wherein the first end of the second power switch QX2 is, for example, a drain end of the N-type transistor, the second end of the second power switch QX2 is, for example, a source end of the N-type transistor, and the control end of the second power switch QX2 is, for example, a gate end of the N-type transistor, but the present embodiment is not limited thereto. In some embodiments, the second power switch QX2 may also be a P-type transistor or other suitable transistors.

The detection module 150 includes a first detection unit 220 and a second detection unit 230. The first detection unit 220 is coupled to the first switch module 130 (i.e., the first end of the first power switch QX1). The first detection unit 220 detects and counts the first conduction times of the first switch module 130 (i.e., the first power switch QX1), and generates a first detection signal DS1 according to the first conduction times and the preset conduction times. In this embodiment, the first detection unit 220, for example, detects the voltage VDS (i.e., the drain-source voltage) of the first end of the first power switch QX1 as a basis for the first conduction times of the first switch module 130 (i.e., the first power switch QX1).

For example, as shown in FIG. 3 , when the first control signal CS1 is at a high voltage level, the first switch module 130 (i.e., the first power switch QX1) is turned on, and the first detection unit 220 detects that the voltage VDS at the first end of the first power switch QX1 is at a low voltage level. Then, when the first control signal CS1 switches from a high voltage level to a low voltage level, the first switch module 130 (i.e., the first power switch QX1) is not turned on, and the first detection unit 220 detects that the voltage VDS at the first end of the first power switch QX1 is at a high voltage level. Afterwards, when the first control signal CS1 switches from a low voltage level to a high voltage level, the first switch module 130 (i.e., the first power switch QX1) is turned on. At this time, the first detection unit 220 detects that the voltage VDS of the first end of the first power switch QX1 decreases from a high voltage level to a low voltage level (i.e., label "310"), and the first detection unit 220 can use this low voltage level (i.e., label "310") as the first conduction number of the first switch module 130 (i.e., the first power switch QX1), that is, the first conduction number is 1. The rest is analogous.

The second detection unit 230 is coupled to the second switch module 140 (i.e., the first end of the second power switch QX2) and the first detection unit 220. The second detection unit 230 detects and counts the second conduction times of the second switch module 140 (i.e., the second power transistor QX2), and generates a second detection signal DS2 according to the second conduction times and the preset conduction times. In this embodiment, the second detection unit 230, for example, detects the voltage of the first end of the second power switch QX2 (i.e., the drain-source voltage) as a basis for the second conduction times of the second switch module 140 (i.e., the second power switch QX2). The second detection unit 230 detecting the second conduction number is the same as or similar to the first detection unit 220 detecting the first conduction number. Please refer to the above description of the embodiment of the first detection unit 220, so it will not be repeated here.

In some embodiments, the first detection unit 220 can determine whether the first conduction number is the same as the preset conduction number. When it is determined that the first conduction number is not the same as the preset conduction number, the first detection unit 220 can generate a first detection signal DS1 of a first voltage level (e.g., a high voltage level). When it is determined that the first conduction number is the same as the preset conduction number, the first detection unit 220 can generate a first detection signal DS1 of a second voltage level (e.g., a low voltage level) and reset the first conduction number and stop the action. At the same time, the first detection unit 220 can generate an enable signal ENS to the second detection unit 230, so that the second detection unit 230 starts to operate to generate a second detection signal DS2 of a first voltage level (eg, a high voltage level), and detect and count the second conduction times.

Similarly, the second detection unit 230 can determine whether the second conduction number is the same as the preset conduction number. When it is determined that the second conduction number is not the same as the preset conduction number, the second detection unit 230 can generate a second detection signal DS2 of a first voltage level (e.g., a high voltage level). When it is determined that the second conduction number is the same as the preset conduction number, the second detection unit 230 can generate a second detection signal DS2 of a second voltage level (e.g., a low voltage level) and reset the second conduction number and stop the action. At the same time, the second detection unit 230 can generate an enable signal ENS to the first detection unit 220, so that the first detection unit 220 starts to operate to generate a first detection signal DS1 of a first voltage level (eg, a high voltage level), and detect and count the first conduction times.

The logic module 160 includes a first logic unit 240 and a second logic unit 250. The first logic unit 240 has a first input terminal, a second input terminal and an output terminal. The first input terminal of the first logic unit 240 receives a reference voltage VF. The second input terminal of the first logic unit 240 is coupled to the first detection unit 220 and receives a first detection signal DS1. The output terminal of the first logic unit 240 generates a first logic signal LS1.

The second logic unit 250 has a first input terminal, a second input terminal and an output terminal. The first input terminal of the second logic unit 250 receives a reference voltage VF. The second input terminal of the second logic unit 250 is coupled to the second detection unit 230 and receives a second detection signal DS2. The output terminal of the second logic unit 250 generates a second logic signal LS2. In some embodiments, the first logic unit 240 and the second logic unit 250 are, for example, AND gates, so as to perform an AND operation on the signals received by the first input terminal and the second input terminal.

The output module 180 includes an output diode DO and an output capacitor CO. The output diode DO has a first end (e.g., an anode end) and a second end (e.g., a cathode end). The first end of the output diode DO is coupled to the boost module 120 and receives the boost voltage VB. The second end of the output diode DO generates an output voltage VO. The output capacitor CO has a first end and a second end. The first end of the output capacitor CO is coupled to the second end of the output diode DO. The second end of the output capacitor CO is coupled to the ground end GND.

In the overall operation of the power supply device 100, the boost module 120 receives the DC voltage VDC to generate the boost voltage VB. Then, the control module 170 generates the first control signal CS1 to switch the first power switch QX1 (i.e., the first switch module 130) between conducting and non-conducting. Afterwards, when the first detection unit 220 (i.e., the detection module 150) detects that the voltage VDS at the first end of the first power switch QX1 decreases from a high voltage level to a low voltage level for the first time (i.e., as indicated by the label "310" in FIG. 3), the first detection unit 220 counts the first conduction times of the first power switch QX1 (i.e., the first switch module 130) as 1.

Then, the first detection unit 220 compares the first conduction number (i.e., 1 time) with the preset conduction number (i.e., 2 times) to determine whether the first conduction number (i.e., 1 time) is the same as the preset conduction number (i.e., 2 times). When it is determined that the first conduction number (i.e., 1 time) is not the same as the preset conduction number (i.e., 2 times), the first detection unit 220 generates a first detection signal DS1 of a first voltage level (e.g., a high voltage level), and transmits the first detection signal DS1 of the first voltage level (e.g., a high voltage level) to the first logic unit 240 (i.e., the logic module 160).

Afterwards, the first logic unit 240 (i.e., the logic module 160) performs an AND operation on the first detection signal DS1 of the first voltage level (e.g., high voltage level) and the reference voltage VF of the high voltage level to generate a first logic signal LS1 of a high logic level, and transmits the first logic signal LS1 of the high logic level to the control module 170. Then, the control module 170 continuously generates the first control signal CS1 according to the first logic signal LS1 of the high logic level.

Thereafter, when the first detection unit 220 (i.e., the detection module 150) detects that the voltage VDS at the first end of the first power switch QX1 decreases from the high voltage level to the low voltage level for the second time (i.e., as indicated by the label “310” in FIG. 3 ), the first detection unit 220 counts the first conduction times of the first power switch QX1 (i.e., the first switch module 130) as 2 times.

Then, the first detection unit 220 compares the first conduction number (i.e., 2 times) with the preset conduction number (i.e., 2 times) to determine whether the first conduction number (i.e., 2 times) is the same as the preset conduction number (i.e., 2 times). When determining that the first conduction number (i.e., 2 times) is the same as the preset conduction number (i.e., 2 times), the first detection unit 220 generates a first detection signal DS1 of a second voltage level (e.g., a low voltage level), and transmits the first detection signal DS1 of the second voltage level (e.g., a low voltage level) to the first logic unit 240 (i.e., the logic module 160), and the first detection unit 220 resets the first conduction number (i.e., resets 2 times to 0 times) and stops the action. At the same time, the first detection unit 220 can generate an enable signal ENS to the second detection unit 230, so that the second detection unit 230 starts to operate to generate a second detection signal DS2 of a first voltage level (eg, a high voltage level), and detect and count the second conduction times.

Afterwards, the first logic unit 240 (i.e., the logic module 160) performs an AND operation on the first detection signal DS1 of the second voltage level (e.g., the low voltage level) and the reference voltage VF of the high voltage level to generate a first logic signal LS1 of a low logic level, and transmits the first logic signal LS1 of the low logic level to the control module 170. Then, the control module 170 does not generate the first control signal CS1 according to the first logic signal LS1 of the low logic level.

On the other hand, the second logic unit 250 (i.e., the logic module 160) receives the second detection signal DS2 of the first voltage level (e.g., a high voltage level) generated by the second detection unit 230, and performs an AND operation on the second detection signal DS2 of the first voltage level (e.g., a high voltage level) and the reference voltage VF of the high voltage level to generate a second logic signal LS2 of a high logic level, and transmits the second logic signal LS2 of the high logic level to the control module 170. Then, the control module 170 generates a second control signal CS2 according to the second logic signal LS2 of the high logic level, so that the second power switch QX2 (i.e., the second switch module 140) performs a switching operation between conducting and non-conducting. The control operation of the second power switch QX2 (i.e., the second switch module 140) is the same as or similar to the control operation of the first power switch QX1 (i.e., the first switch module 130), and the description of the embodiment of the control operation of the first power switch QX1 (i.e., the first switch module 130) can be referred to above, so it is not repeated here.

FIG. 4 is a waveform diagram of the boost inductor current and the control signal of a conventional power supply. FIG. 5 is a waveform diagram of the boost inductor current, the first control signal, and the second control signal of a power supply device according to an embodiment of the present invention. Please refer to FIG. 4 and FIG. 5, the reference numeral "IL" is the boost inductor current of the conventional power supply, the reference numeral "CS" is the control signal of the conventional power supply, the reference numeral "ILM" is the boost inductor current of the power supply device 100 of the present embodiment, the reference numeral "CS1" is the first control signal of the power supply device 100 of the present embodiment, and the reference numeral "CS2" is the second control signal of the power supply device 100 of the present embodiment.

In FIG. 4, it can be seen that under high switching frequency, the response speed of the power switch cannot keep up with the continuous current (i.e., the control signal CS and the boost inductor current IL cannot correspond), resulting in the boost inductor current IL being abnormal and leaving the continuous mode. In FIG. 5, the boost inductor current ILM, the first control signal CS1 and the second control signal CS2 of the power supply device 100 of the embodiment of the present invention can correspond, that is, the first power switch QX1 and the second power switch QX2 can keep up with the boost inductor current ILM. In this way, the power supply device 100 of the embodiment of the present invention can effectively realize the boost inductor current in the precise continuous current mode, prevent the boost conversion circuit from operating abnormally, improve the boost ratio and power factor, and increase the convenience of use.

In summary, the power supply device disclosed in the present invention detects the first conduction number of the first switch module through the detection module, and generates a first detection signal according to the first conduction number and the preset conduction number, and detects the second conduction number of the second switch module, and generates a second detection signal according to the second conduction number and the preset conduction number. The logic module generates a first logic signal according to the first detection signal and a reference voltage, and generates a second logic signal according to the second detection signal and the reference voltage. The control module generates a first control signal according to the first logic signal, and generates a second control signal according to the second logic signal, so as to intermittently control the first switch module and the second switch module to perform switching operations. In this way, the boost conversion ratio and power factor can be effectively improved, and the convenience of use can be increased.

Although the present invention is disclosed as above by the embodiments, it is not intended to limit the scope of the present invention. Any person with ordinary knowledge in the relevant technical field can make some changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be defined by the scope of the attached patent application.

100: Power supply device 110: Rectifier module 120: Boost module 130: First switch module 140: Second switch module 150: Detection module 160: Logic module 170: Control module 180: Output module 210: AC power supply 220: First detection unit 230: Second detection unit 240: First logic unit 250: Second logic unit 310: Low voltage level D1, D2, D3, D4: Rectifier diode LM: Boost inductor QX1: First power switch QX2: Second power switch DO: Output diode CO: Output capacitor GND: ground terminal VAC: AC voltage VDC: DC voltage VB: boost voltage CS: control signal CS1: first control signal CS2: second control signal DS1: first detection signal DS2: second detection signal LS1: first logic signal LS2: second logic signal ENS: enable signal VF: reference voltage VO: output voltage IL, ILM: boost inductor current VDS: voltage

FIG. 1 is a schematic diagram of a power supply device according to an embodiment of the present invention. FIG. 2 is a detailed schematic diagram of a power supply device according to an embodiment of the present invention. FIG. 3 is a waveform diagram of a first control signal and a voltage at a first end of a first power switch according to an embodiment of the present invention. FIG. 4 is a waveform diagram of a boost inductor current and a control signal of a conventional power supply. FIG. 5 is a waveform diagram of a boost inductor current, a first control signal, and a second control signal of a power supply device according to an embodiment of the present invention.

100: Power supply device

110: Rectifier module

120:Boost module

130: First switch module

140: Second switch module

150: Detection module

160:Logic module

170: Control module

180: Output module

VAC: alternating current voltage

VDC: DC voltage

VB: boost voltage

CS1: First control signal

CS2: Second control signal

DS1: First detection signal

DS2: Second detection signal

LS1: First logic signal

LS2: Second logic signal

VF: reference voltage

VO: output voltage

Claims (11)

A power supply device includes: A rectifier module, receiving an AC voltage and converting the AC voltage into a DC voltage; A boost module, coupled to the rectifier module, receiving the DC voltage to generate a boost voltage; A first switch module, coupled to the boost module, determining whether to conduct according to a first control signal; A second switch module, coupled to the boost module, determining whether to conduct according to a second control signal; A detection module coupled to the first switch module and the second switch module, detecting a first conduction number of the first switch module, and generating a first detection signal according to the first conduction number and a preset conduction number, and detecting a second conduction number of the second switch module, and generating a second detection signal according to the second conduction number and the preset conduction number; A logic module coupled to the detection module, generating a first logic signal according to the first detection signal and a reference voltage, and generating a second logic signal according to the second detection signal and the reference voltage; and A control module is coupled to the first switch module, the second switch module and the logic module, receives the first logic signal and the second logic signal, generates the first control signal according to the first logic signal, and generates the second control signal according to the second logic signal. A power supply device as claimed in claim 1, wherein the rectifier module includes a bridge rectifier. The power supply device of claim 1, wherein the boost module comprises: A boost inductor having a first end and a second end, the first end of the boost inductor receiving the DC voltage, and the second end of the boost inductor generating the boost voltage. The power supply device of claim 1, wherein the first switch module comprises: A first power switch having a first end, a second end and a control end, the first end of the first power switch is coupled to the boost module and the detection module, the second end of the first power switch is coupled to a ground end, the control end of the first power switch is coupled to the control module, and receives the first control signal. The power supply device of claim 1, wherein the second switch module comprises: A second power switch having a first end, a second end and a control end, the first end of the second power switch being coupled to the boost module and the detection module, the second end of the second power switch being coupled to a ground end, the control end of the second power switch being coupled to the control module and receiving the second control signal. The power supply device of claim 1, wherein the detection module comprises: a first detection unit coupled to the first switch module, detecting and counting the first conduction times of the first switch module, and generating the first detection signal according to the first conduction times and the preset conduction times; and a second detection unit coupled to the second switch module and the first detection unit, detecting and counting the second conduction times of the second switch module, and generating the second detection signal according to the second conduction times and the preset conduction times. The power supply device of claim 6, wherein the first detection unit determines whether the first conduction number is the same as the preset conduction number. When it is determined that the first conduction number is not the same as the preset conduction number, the first detection unit generates a first detection signal of a first voltage level. When it is determined that the first conduction number is the same as the preset conduction number, the first detection unit generates a first detection signal of a second voltage level and resets the first conduction number and stops the operation, and generates an enable signal to the second detection unit to start the operation of the second detection unit to generate the second detection signal of the first voltage level and detect and count the second conduction number; The second detection unit determines whether the second conduction number is the same as the preset conduction number. When it is determined that the second conduction number is not the same as the preset conduction number, the second detection unit generates the second detection signal of the first voltage level. When it is determined that the second conduction number is the same as the preset conduction number, the second detection unit generates the second detection signal of the second voltage level and resets the second conduction number and the same-address action, and generates the enable signal to the first detection unit, so that the first detection unit starts to operate to generate the first detection signal of the first voltage level, and detect and count the first conduction number. The power supply device of claim 1, wherein the logic module comprises: a first logic unit having a first input terminal, a second input terminal and an output terminal, the first input terminal of the first logic unit receiving the reference voltage, the second input terminal of the first logic unit receiving the first detection signal, and the output terminal of the first logic unit generating the first logic signal; and A second logic unit has a first input terminal, a second input terminal and an output terminal. The first input terminal of the second logic unit receives the reference voltage, the second input terminal of the second logic unit receives the second detection signal, and the output terminal of the second logic unit generates the second logic signal. A power supply device as claimed in claim 1, wherein the preset conduction number is associated with a switching frequency of the first switch module and the second switch module. The power supply device of claim 1 further includes: An output module coupled to the boost module, receiving the boost voltage to generate an output voltage. A power supply device as claimed in claim 10, wherein the output module comprises: an output diode having a first end and a second end, the first end of the output diode being coupled to the boost module and receiving the boost voltage, and the second end of the output diode generating the output voltage; and an output capacitor having a first end and a second end, the first end of the output capacitor being coupled to the second end of the output diode, and the second end of the output capacitor being coupled to a ground end.

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