Control circuit based on power conversion chip

Abstract

A control circuit based on a power conversion chip includes a power conversion chip, a plurality of first switching elements, and a controller. The power conversion chip has a first pin, a second pin, a third pin, and a fourth pin. The first pin is connected to a first AC input terminal, the second pin is connected to a second AC input terminal, the fourth pin is connected to the second pin, and the power conversion chip outputs a negative DC voltage through the third pin. The plurality of first switching elements are respectively connected to the second AC input terminal. The controller is connected to the power conversion chip and the plurality of first switching elements, and is used to control the conduction state of the plurality of first switching elements respectively driven by the negative DC voltage.

Description

Technical Field

[0001] This utility model relates to a control circuit based on an energy conversion chip. Background Technology

[0002] Currently, control circuits mostly rely on external power modules to provide DC voltage to drive the controller, often requiring additional inductors and complex circuit designs, resulting in complex system structures and increased costs. Furthermore, the controller cannot obtain negative DC voltage from AC power, limiting applications with specific power supply or control requirements. Utility Model Content

[0003] In view of the above, this utility model provides a control circuit based on an energy conversion chip.

[0004] An embodiment of this utility model discloses a control circuit based on a power conversion chip, comprising a power conversion chip, a plurality of first switching elements, and a controller. The power conversion chip has a first pin, a second pin, a third pin, and a fourth pin. The first pin is connected to a first AC input terminal, the second pin is connected to a second AC input terminal, the fourth pin is connected to the second pin, and the power conversion chip outputs a negative DC voltage through the third pin. The plurality of first switching elements are respectively connected to the second AC input terminal. The controller is connected to the power conversion chip and the plurality of first switching elements, and is used to control the conduction state of the plurality of first switching elements respectively under the drive of the negative DC voltage.

[0005] According to the control circuit based on the power conversion chip disclosed in the above embodiments, the power conversion chip can convert AC power into negative DC voltage, and the negative DC voltage drives the controller to control the conduction state of multiple switching elements, thereby controlling the open or closed circuit power supply, which can meet the needs of various electronic products on the market.

[0006] The above description of the present utility model and the following description of the embodiments are used to demonstrate and explain the principle of the present utility model, and to provide a further explanation of the protection scope of the present utility model. Attached Figure Description

[0007] Figure 1 This is a functional block diagram of a control circuit based on a power conversion chip, drawn according to an embodiment of the present invention.

[0008] Figure 2 This is a circuit diagram of a control circuit based on an energy conversion chip, drawn according to another embodiment of the present invention.

[0009] Figure 3 This is a functional block diagram of a power conversion chip drawn according to an embodiment of the present invention.

[0010] Figure 4 This is a circuit diagram of the negative voltage conversion sub-circuit of the power conversion chip according to an embodiment of the present invention.

[0011] Figure 5 This is a circuit diagram of the negative voltage conversion sub-circuit of the power conversion chip according to another embodiment of the present invention.

[0012] Figure 6 Based on Figure 5 The circuit diagram of the oscillator of the power conversion chip is shown in the embodiment.

[0013] Figure 7 Based on Figure 5 The circuit diagram of the level shifter of the power conversion chip is shown in the embodiment.

[0014] Figure 8 This is a schematic diagram illustrating the control signals of a power conversion chip according to an embodiment of the present invention.

[0015] Figure 9 This is a functional block diagram of a power conversion chip drawn according to another embodiment of the present invention.

[0016] [Explanation of Labels in the Attached Image]

[0017] 1,1': Control circuit based on power conversion chip

[0018] 11,11': Power conversion chip

[0019] 111: First position

[0020] 112: Second foot position

[0021] 113: Third foot position

[0022] 114: Fourth position

[0023] 115: Fifth position

[0024] 12-1, 12-N: First switching element

[0025] 13: Controller

[0026] 14: AC-DC converter sub-circuit

[0027] 141: Rectifier

[0028] 142: Sample-and-hold sub-circuit

[0029] 143: Linear regulator

[0030] 144, 145: Capacitors

[0031] 15,15': Negative voltage conversion sub-circuit

[0032] 151: Charge Pump

[0033] 1511: Second switching element

[0034] 1512: Third switching element

[0035] 1513: Fourth Switching Element

[0036] 1514: Fifth Switching Element

[0037] 152, 153: Capacitors

[0038] 154: Oscillator

[0039] 1541, 1543, 1544, 1552, 1553, 1554, 1555, 1556, 1557: Switching elements

[0040] 1542: Resistor

[0041] 1545, 1551, 1558: Amplifiers

[0042] 1546: Driver

[0043] 155: Level shifter

[0044] AC_In1, AC_In2: AC input terminals

[0045] CA1, CA2, CA3, CA4: Capacitors

[0046] COM: Common Terminal

[0047] D1: Diode

[0048] P1: Endpoint

[0049] R1: Resistor

[0050] OUT_1, OUT_N: Output terminals

[0051] V in Input voltage

[0052] PV: Positive DC voltage

[0053] NV: Negative DC voltage

[0054] n1: Node

[0055] T1-T11: Endpoints

[0056] t1, t2: Time points

[0057] C1: First control signal

[0058] C2: Second control signal Detailed Implementation

[0059] The following detailed description of the features and advantages of this utility model in the embodiments is sufficient to enable any person skilled in the art to understand the technical content of this utility model and implement it accordingly. Based on the content, scope of protection, and drawings disclosed in this specification, any person skilled in the art can easily understand the related objectives and advantages of this utility model. The following embodiments are further detailed in illustrating the viewpoints of this utility model, but are not intended to limit the scope of this utility model in any way.

[0060] Please refer to Figure 1 , Figure 1 This is a functional block diagram of a control circuit based on a power conversion chip, drawn according to an embodiment of the present invention. Figure 1 As shown, the control circuit 1 based on the power conversion chip includes a power conversion chip 11, a plurality of first switching elements 12-1 to 12-N, and a controller 13. The power conversion chip 11 has a first pin 111, a second pin 112, a third pin 113, and a fourth pin 114. The first pin 111 is connected to a first AC input terminal AC_In1. The second pin 112 is connected to a second AC input terminal AC_In2. The fourth pin 114 is connected to the second pin 112. The power conversion chip 11 outputs a negative DC voltage through the third pin 113. The plurality of first switching elements 12-1 to 12-N are respectively connected to the second AC input terminal AC_In2. The controller 13 is connected to the power conversion chip 11 and the plurality of first switching elements 12-1 to 12-N, and is used to control the conduction state of the plurality of first switching elements 12-1 to 12-N respectively under the drive of the negative DC voltage. In one embodiment, when the controller 13 controls the conduction state of the plurality of first switching elements 12-1 to 12-N, it can further conduct to the output terminals OUT_1 to OUT_N.

[0061] In one embodiment, each of the plurality of first switching elements 12-1 to 12-N is a bidirectional AC switch. For example, the bidirectional AC switch may be a bidirectional thyristor (TRIAC) for controlling the bidirectional conduction of AC current. Specifically, each bidirectional AC switch may include two anti-parallel thyristors, and the gate drive circuit ensures that conduction is triggered in both the positive and negative half-cycles of the AC cycle.

[0062] In one embodiment, the number of the plurality of first switching elements 12-1 to 12-N is 4 to 6. For example, the plurality of first switching elements 12-1 to 12-N may be configured as a combination of bidirectional thyristor devices or insulated-gate bipolar transistors. Specifically, the number of switching elements can be selected according to the load power requirements; when the system is applied in a low-power mode, 4 switching elements can be configured; when applied in a high-power mode, 6 switching elements can be configured to achieve current shunting and heat dissipation.

[0063] In one embodiment, the first AC input terminal AC_In1 connected to the first pin 111 is the live wire of a socket, and the second AC input terminal AC_In2 connected to the second pin 112 is the neutral wire of a socket. For example, the AC input terminals can be used for a wide voltage range of 90 volts to 240 volts and comply with general electrical safety standards. Specifically, an overcurrent protection element (such as a fuse or circuit breaker) can be connected in series between the first pin 111 and the live wire, and the second pin 112 can be directly connected to the neutral wire to form a loop, wherein the wire color can be adjusted according to local standards (e.g., brown or red for the live wire and blue or black for the neutral wire).

[0064] Please refer to Figure 2 , Figure 2 This is a circuit diagram illustrating a control circuit based on a power conversion chip, according to another embodiment of the present invention. Figure 2 As shown, the control circuit 1' based on the power conversion chip includes, in addition to, the... Figure 1 In addition to the same power conversion chip 11, multiple first switching elements 12-1 to 12-N, and controller 13, it further includes capacitors CA1 to CA4, diode D1, terminal P1, and resistor R1. The common terminal COM is connected to the AC input terminal AC_In1 via resistor R1. The AC input terminal AC_In1 is connected to the power conversion chip 11 via resistor R1 and diode D1 for rectification and input voltage. The AC input terminal AC_In2 is connected to the ground terminal of the power conversion chip 11 and outputs a voltage to the power conversion chip 11 after filtering and voltage regulation by capacitor CA4. The number of the multiple first switching elements 12-1 and 12-N is... Figure 2 The figure schematically illustrates two, however, this disclosure is not limited to what is shown in the figure. Preferably, the number of the plurality of first switching elements is four to six.

[0065] In this example, capacitor CA1 can be connected in series between the AC input terminal AC_In1 and the power supply terminal (VDD) of the power conversion chip 11, and also in series with the ground terminal (GND) of the power conversion chip 11. Capacitor CA1 can form an energy storage filter capacitor to stabilize the rectified DC voltage after input. Capacitor CA1 can, for example, have a capacitance value of 470 microfarads (μF). Capacitor CA2 is connected to two pins of the power conversion chip 11 and can form a coupling capacitor in the negative voltage generation unit to transfer charge during the switching cycle and further generate a negative voltage. Capacitor CA2 can, for example, have a capacitance value of 0.33 microfarads. Capacitor CA3 can be located at the output pin of the power conversion chip 11 and can serve as a filter capacitor for terminal P1, and terminal P1 can, for example, be connected to the AC input terminal AC_In2. Capacitor CA3 can, for example, have a capacitance value of 2.2 microfarads. Capacitor CA4 is connected to the power supply terminal (VDD) and ground terminal (GND) of the power conversion chip 11. Together with capacitor CA1, it is used for smoothing and energy storage at the positive voltage output terminal, further providing a stable voltage for use by the back-end controller 13. Capacitor CA4 may have, for example, a capacitance value of 3.3 microfarads. By configuring capacitors CA1 to CA4 as described above, the traditional inductor-based architecture can be simplified, effectively reducing cost and size.

[0066] Please refer to Figure 3 , Figure 3 This is a functional block diagram of a power conversion chip drawn according to an embodiment of the present invention. Figure 3 As shown, the power conversion chip 11 may include a first pin 111, a third pin 113, a fifth pin 115, an AC-DC converter sub-circuit 14, and a negative voltage converter sub-circuit 15. The first pin 111 is used to receive the input voltage V of an AC power source. in Pin 113 is used to output a negative DC voltage NV. Pin 115 is a selectively configured component used to output a positive DC voltage PV. An AC-DC converter sub-circuit 14 is connected to pins 111 and 115 to convert the input voltage V of the AC power supply. in The positive DC voltage PV is converted to a positive DC voltage PV. The negative voltage conversion sub-circuit 15 is connected to the AC-DC conversion sub-circuit 14 and is used to convert the positive DC voltage PV to a negative DC voltage NV.

[0067] In this example, the power conversion chip 11 may have a package and multiple pins. The first pin 111 is used to receive AC power input from the mains, such as an AC power supply with a voltage of 90 to 240 volts. The third pin 113 is used to output a low-voltage negative DC power, such as a DC power of -5 volts. The fifth pin 115 is used to output a low-voltage positive DC power, such as a DC power of 5 volts. Alternatively, the power conversion chip 11 may also include multiple pins for outputting low-voltage positive DC power, such as pins for outputting DC power of 3.3 volts. The power conversion chip 11 may also include multiple pins for outputting low-voltage negative DC power, such as pins for outputting DC power of -3.3 volts. Overall, the power conversion chip 11 of this invention may include, for example, 8 pins, 10 pins, or 16 pins, and this invention is not limited thereto. In this example, the power conversion chip 11 may not contain any inductor components.

[0068] AC-DC converter circuit 14 can convert the input voltage V received from the first pin 111 into DC-DC converter voltage V. in It is converted to a positive DC voltage PV, and the positive DC voltage PV is transmitted to pin 5 115 and the negative voltage conversion sub-circuit 15. For the internal structure of the negative voltage conversion sub-circuit 15, please refer to [reference needed]. Figure 4 , Figure 4 This is a circuit diagram of the negative voltage conversion sub-circuit of an energy conversion chip, drawn according to an embodiment of the present invention. Figure 4 As shown, in this example, the negative voltage conversion sub-circuit 15 of the power conversion chip 11 may include a charge pump 151, a first capacitor 152, and a second capacitor 153. The charge pump 151 includes a second switching element 1511, a third switching element 1512, a fourth switching element 1513, and a fifth switching element 1514. One end of the second switching element 1511 is connected to a pin for receiving a positive DC voltage PV. One end of the third switching element 1512 is connected to the other end of the second switching element 1511, and the other end of the third switching element 1512 is grounded. One end of the fourth switching element 1513 is grounded, and the fifth switching element 1514... One end of 14 is connected to the other end of the fourth switching element 1513, and the other end of the fifth switching element 1514 is connected to the third pin 113 for outputting negative DC voltage NV. One end of the first capacitor 152 is connected between the second switching element 1511 and the third switching element 1512 and receives positive DC voltage PV through the second switching element 1511. The other end of the first capacitor 152 is connected between the fourth switching element 1513 and the fifth switching element 1514. One end of the second capacitor 153 is grounded, and the other end of the second capacitor 153 is connected to the third pin 113 and is charged by the first capacitor 152 through the fifth switching element 1514.

[0069] In this example, the second switching element 1511, the third switching element 1512, the fourth switching element 1513, and the fifth switching element 1514 can be controlled by a control signal with a specific timing sequence to achieve the effect of flipping the positive DC voltage PV to a negative DC voltage NV. Specifically, in a first cycle, the second switching element 1511 and the fourth switching element 1513 can be turned on, while the third switching element 1512 and the fifth switching element 1514 can be turned off. In this first cycle, the positive DC voltage PV charges the first capacitor 152, so that the terminals of the first capacitor 152 have the same voltage across the positive DC voltage PV. Further, in a second cycle, the third switching element 1512 and the fifth switching element 1514 can be turned on, while the second switching element 1511 and the fourth switching element 1513 can be turned off. In this second cycle, the sign of the voltage across the first capacitor 152 is reversed, and the first capacitor 152 charges the second capacitor 153, causing one end of the second capacitor 153 to have a negative DC voltage NV opposite to the positive DC voltage PV. The first to fourth switching elements 1511 to 1514 in this example can be implemented using various transistors, and this invention is not limited thereto.

[0070] Please refer to Figure 5 , Figure 5 This is a circuit diagram of the negative voltage conversion sub-circuit of the power conversion chip, drawn according to another embodiment of the present invention. Figure 5 As shown, the negative voltage conversion sub-circuit 15' in this example includes, in addition to, the same as... Figure 4 In addition to the identical second to fifth switching elements 1511 to 1514, the first capacitor 152, and the second capacitor 153, an oscillator 154 and a level shifter 155 are further included. The oscillator 154 is connected to the second switching element 1511, the third switching element 1512, the fourth switching element 1513, and the fifth switching element 1514, and generates a frequency signal to turn on the second switching element 1511 and the fourth switching element 1513 and turn off the third switching element 1512 and the fifth switching element 1514 during a first cycle, and to turn on the third switching element 1512 and the fifth switching element 1514 and turn off the second switching element 1511 and the fourth switching element 1513 during a second cycle. The level shifter 155 is connected to the oscillator 154, the fourth switching element 1513, and the fifth switching element 1514, and causes a voltage shift in the frequency signal used by the oscillator 154 to control the fourth switching element 1513 and the fifth switching element 1514.

[0071] Please combine Figure 5 Reference Figure 6 , Figure 6 Based on Figure 5The circuit diagram of the oscillator of the power conversion chip shown in the embodiment is as follows. Figure 6 As shown, the oscillator 154 may include two switching elements 1541 and 1543 and a semiconductor capacitor 1544, wherein switching element 1541 is a P-type transistor and switching element 1543 is an N-type transistor. The source of switching element 1541 is connected to terminal T1, and the drain of switching element 1541 is connected to the drain of switching element 1543. The source of switching element 1543 is grounded. Two resistors 1542 are disposed between the two switching elements 1541 and 1543. The gate of switching element 1541 is connected to terminal T2 and controlled by a control signal provided by terminal T2. When the control signal provided by terminal T2 controls switching element 1541 to conduct, the first signal provided by terminal T1 passes through the source and drain of switching element 1541 and through the two resistors 1542. The gate of switching element 1543 is connected to terminal T3 and controlled by a control signal provided by terminal T3. When the control signal provided by terminal T3 turns on the switching element 1543, the first signal is grounded through the switching element 1543. The gate of the semiconductor capacitor 1544 is connected between the two resistors 1542, and the base of the semiconductor capacitor 1544 is grounded. The voltage provided by terminal T5 can serve as the power supply signal for amplifier 1545 and driver 1546. Furthermore, the first signal can be transmitted to driver 1546 through the two amplifiers 1545. Then, driver 1546 can generate the aforementioned frequency signal according to the first signal and transmit it through terminal T4 to... Figure 5 The node n1 and level shifter 155 control the switching operation of the second switching element 1511 to the fifth switching element 1514. For example, the control signal can be a square wave oscillation signal with a frequency of 200 kHz and a duty cycle of 50%, and the driver 1546 can generate higher output power.

[0072] Please combine Figure 5 Reference Figure 7 , Figure 7 Based on Figure 5 The circuit diagram of the level shifter of the power conversion chip shown in the embodiment is as follows. Figure 7As shown, the level shifter 155 may include two front-end amplifiers 1551, six switching elements 1552 to 1557, and two rear-end amplifiers 1558. The two amplifiers 1551 are connected to terminal T6 and are driven by a voltage supplied to terminal T7. The sources of switching elements 1552 and 1553 are connected to terminals T8 and T9, respectively, and the drains of switching elements 1552 and 1553 are connected to the drains of switching elements 1554 and 1555, respectively. The sources of switching elements 1554 and 1555 are connected to the drains of switching elements 1556 and 1557, respectively. The sources of switching elements 1556 and 1557 are grounded. The gate of switching element 1556 is connected to amplifier 1558. The drain of switching element 1557 is connected to amplifier 1558. Amplifier 1558 is driven by a voltage supplied to terminal T10 and outputs a signal through terminal T11. In this example, terminal T6 is used to receive the aforementioned frequency signal from oscillator 154. This frequency signal, after being modulated by amplifier 1551, serves as the gate control signal for switching elements 1552 and 1553. By using this frequency signal as the gate control signal, the six switching elements 1552 to 1557 can retain the control timing information of the frequency signal and have a voltage level offset. Finally, the second signal generated by level shifter 155 can be transmitted via terminal T10 to... Figure 5 The fourth switching element 1513 and the fifth switching element 1514. The polarity of the frequency signal generated by the oscillator 154 can be changed through this level shifter 155.

[0073] Please combine Figure 5 Reference Figure 8 , Figure 8 This is a schematic diagram illustrating the control signals of a power conversion chip according to an embodiment of the present invention. Figure 8 As shown, the first control signal C1 controls the second switching element 1511 and the third switching element 1512, and the second control signal C2 controls the fourth switching element 1513 and the fifth switching element 1514. The first control signal C1 is the signal directly output from the oscillator 154 to node n1 (to output to the second switching element 1511 and the third switching element 1512), and the second control signal C2 is the signal output from the level shifter 155 to the fourth switching element 1513 and the fifth switching element 1514. In this example, the first cycle of the first control signal C1 and the second cycle of the second control signal C2 are staggered in timing, and the first cycle and the second cycle have the same duration. It should be noted that, as... Figure 3As shown, in this example, the second switching element 1511 and the fourth switching element 1513 are P-type transistors, and the third switching element 1512 and the fifth switching element 1514 are N-type transistors. The source of the second switching element 1511 is connected to pin 5 115, the drain of the second switching element 1511 is connected to the drain of the third switching element 1512, the source of the third switching element 1512 is grounded, the source of the fourth switching element 1513 is grounded, the drain of the fourth switching element 1513 is connected to the drain of the fifth switching element 1514, and the source of the fifth switching element 1514 is grounded. With this configuration, the second switching element 1511 and the fourth switching element 1513 can be simultaneously turned on or off by the first control signal C1, and the third switching element 1512 and the fifth switching element 1514 can be simultaneously turned on or off by the second control signal C2, and the conduction periods of the first control signal C1 and the second control signal C2 can be staggered.

[0074] Please refer to Figure 9 , Figure 9 This is a functional block diagram of a power conversion chip drawn according to another embodiment of the present invention. Figure 9 As shown, the power conversion chip 11' in this example includes and Figure 3 The circuit includes a first pin 111, a third pin 113, a fifth pin 115, an AC-DC converter, and a negative voltage converter 15. The AC-DC converter includes a rectifier 141, a sample-and-hold (SLD) circuit 142, a linear regulator 143, a third capacitor 144, and a fourth capacitor 145. The rectifier 141 is connected to the first pin 111, and the SLD circuit 142 is connected to the rectifier 141. The linear regulator 143 is connected to the SLD circuit 142. The third capacitor 144 is connected between the SLD circuit 142 and the linear regulator 143 and grounded. The fourth capacitor 145 is connected between the linear regulator 143 and the fifth pin 115 and grounded. With this configuration, the power conversion chip 11' in this example can use a rectifier 141, a sample-and-hold sub-circuit 142, a linear regulator 143, a third capacitor 144, and a fourth capacitor 145 to convert the AC mains input voltage V in The positive DC voltage PV is converted to low-voltage DC power, and then the negative DC voltage PV is converted to a negative DC voltage NV using a negative voltage conversion sub-circuit 15. The rectifier, sample-and-hold sub-circuit, and low-dropout regulator (LDO) described above can be implemented in ways that are understandable to those skilled in the art, and will not be elaborated here. Furthermore, various embodiments of the power conversion chip of this invention can be combined with each other, and are not limited to the embodiments described above.

[0075] According to the control circuit based on the power conversion chip in the above embodiment, the power conversion chip can convert AC power into negative DC voltage, and the negative DC voltage drives the controller to control the conduction state of multiple switching elements, thereby controlling the open or closed circuit of the power supply, which can meet the needs of various electronic products on the market.

Claims

1. A control circuit based on an electrical energy conversion wafer, characterized by Include: A power conversion chip has a first pin, a second pin, a third pin, and a fourth pin. The first pin is used to connect to a first AC input terminal, the second pin is used to connect to a second AC input terminal, the fourth pin is connected to the second pin, and the power conversion chip is used to output a negative DC voltage through the third pin. A plurality of first switching elements, each of which is connected to the second AC input terminal; and A controller is connected to the power conversion chip and the plurality of the first switching elements, and is used to control the conduction state of the plurality of the first switching elements respectively driven by the negative DC voltage.

2. The control circuit based on the electric energy conversion wafer according to claim 1, characterized in that Each of the plurality of the first switching elements is a bidirectional AC switch.

3. The control circuit based on the electric energy conversion wafer according to claim 1, characterized in that, The number of the multiple first switching elements is 4 to 6.

4. The control circuit based on the electric energy conversion wafer according to claim 1, characterized in that, The first AC input terminal connected to the first pin is the live wire of a socket, and the second AC input terminal connected to the second pin is the neutral wire of the socket.

5. The control circuit based on the electric energy conversion wafer as claimed in claim 1, characterized in that, The power conversion chip includes: An AC-DC converter circuit is used to convert an AC power supply into a positive DC voltage; and A negative voltage conversion sub-circuit, connected to the AC-DC conversion sub-circuit, is used to convert the positive DC voltage into the negative DC voltage. Furthermore, the power conversion chip does not contain any inductor components.

6. The control circuit based on the electric energy conversion wafer according to claim 5, characterized in that The negative voltage conversion sub-circuit includes a charge pump, a first capacitor, and a second capacitor. The charge pump includes a second switching element, a third switching element, a fourth switching element, and a fifth switching element. One end of the first capacitor is connected between the second and third switching elements and receives the positive DC voltage through the second switching element. The other end of the first capacitor is connected between the fourth and fifth switching elements. One end of the second capacitor is grounded, and the other end of the second capacitor is connected to the third pin and is charged by the first capacitor through the fifth switching element.

7. The control circuit based on the power conversion chip as described in claim 6, characterized in that, The negative voltage conversion sub-circuit further includes an oscillator connected to the second, third, fourth, and fifth switching elements for generating a frequency signal to turn on the second and fourth switching elements and turn off the third and fifth switching elements during a first cycle, and to turn on the third and fifth switching elements and turn off the second and fourth switching elements during a second cycle, wherein the first cycle and the second cycle are staggered in timing.

8. The control circuit based on the power conversion chip as described in claim 7, characterized in that, The negative voltage conversion sub-circuit further includes a quasi-shifter connected to the oscillator, the fourth switching element, and the fifth switching element, for causing the frequency signal used by the oscillator to control the fourth and fifth switching elements to generate a voltage shift.

9. The control circuit based on the power conversion chip as described in claim 5, characterized in that, The AC-DC converter sub-circuit includes a rectifier, a sample-and-hold sub-circuit, and a linear regulator. The rectifier is connected to the first pin, the sample-and-hold sub-circuit is connected to the rectifier, and the linear regulator is connected to the sample-and-hold sub-circuit.

10. The control circuit based on the power conversion chip as described in claim 9, characterized in that, The AC-DC conversion sub-circuit further includes a third capacitor and a fourth capacitor. The third capacitor is connected between the sample-and-hold sub-circuit and the linear regulator and is grounded. The fourth capacitor is connected to the linear regulator and is grounded.

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