Low-cost suspension power supply circuit based on switched capacitor

Abstract

The invention discloses a low-cost suspension power supply circuit based on a switched capacitor, and relates to the technical field of power supply design. Comprising a power supply VCC, diodes D1-D3, NPN triodes Q1-Q2, a PNP triode Q3, capacitors C1-C3 and a plurality of resistors. Complementary square wave driving signals PWMA and PWMB are utilized to control the triode to be conducted, and charging and discharging and energy transmission of the capacitor are achieved. The power supply VCC and the D1 supply power to the C1, the C1, the D2, the C2 and the Q3 form an energy transmission loop, the C2, the C3 and the D3 form an isolation loop, and the cathode of the C3 is isolated from the ground and serves as an output capacitor to supply power to the outside. Compared with a traditional isolation power supply, the isolation power supply has obvious advantages, basic electronic elements are adopted, and the cost is reduced by 30%-50%; the circuit is designed based on common principles and is simple and easy to implement, and design and production cost is saved; through accurate control and isolation loop design, the output voltage is stable and reliable; the isolation power supply can effectively block electrical interference, is applied to multiple fields of medical treatment, industry and the like, and solves the problems of complex circuit and high cost of a conventional isolation power supply.

Description

Technical Field

[0001] The present application relates to the technical field of power supply design, and in particular to a low-cost floating power supply circuit based on a switched capacitor. Background Art

[0002] In today's electronic equipment and circuit systems, power supply is a key component, and its performance and design directly affect the stability, safety and functionality of the entire system. In many circuit design scenarios, different power supply networks often require different reference grounds, which creates the need for isolated power supplies. For example, in medical electronic equipment, in order to prevent patients from the risk of electric shock and avoid electrical interference between different functional modules, isolated power supplies are the key to ensuring the safe and reliable operation of equipment; in industrial automation control systems, in order to ensure the accuracy and stability of signal transmission, isolated power supplies can effectively block noise interference and improve the system's anti-interference ability.

[0003] At present, there are two main conventional ways to achieve isolated power supply: physical isolation and current limiting conduction. Physical isolation is usually achieved with the help of isolation transformers, optocouplers and other devices with isolation functions. However, this method has obvious cost disadvantages. The procurement cost of isolation transformers and optocouplers is high, and during installation and use, a large circuit board space is required, increasing the overall manufacturing cost. In addition, its complex structure also makes circuit design and debugging more difficult, further increasing the development cost and time cost.

[0004] Another way is to limit the direct flow path of the current through special circuit structures or components to achieve power isolation. However, the circuit design of this method is extremely complex, requiring precise circuit layout and parameter debugging, and requiring extremely high professional knowledge and experience of designers. Moreover, complex circuit structures are often accompanied by higher failure rates, and the subsequent maintenance costs are also increased accordingly.

[0005] Therefore, the complex circuit design and high cost of conventional isolated power supplies have become technical problems that need to be solved urgently. Summary of the invention

[0006] The embodiment of the present application provides a low-cost floating power supply circuit based on a switched capacitor, which is used to solve the following technical problems: the conventional isolated power supply design circuit is complex and costly.

[0007] In the first aspect, an embodiment of the present application provides a low-cost floating power supply circuit based on a switched capacitor, including: a power supply VCC, a first diode D1, a second diode D2, a third diode D3, a first NPN transistor Q1, a second NPN transistor Q2, a PNP transistor Q3, a first capacitor C1, a second capacitor C2, a third capacitor C3, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, and a sixth resistor R6; the positive electrode of the power supply VCC is connected to the anode of the first diode D1, the cathode of the first diode D1 is connected to the first end of the first capacitor C1, the second end of the first capacitor C1 is connected to the collector of the first NPN transistor Q1, and the emitter of the first NPN transistor Q1 is grounded GND; the base of the first NPN transistor Q1 is connected to the first control signal PWM_A through the first resistor R1, and is grounded through the second resistor R2; the base of the second NPN transistor Q2 is connected to the second control signal PWM through the third resistor R3 _B, and is grounded through the fourth resistor R4; the collector of the second NPN transistor Q2 is connected to the base of the PNP transistor Q3 through the fifth resistor R5; the collector of the PNP transistor Q3 is connected to the connection point of the first capacitor C1 and the collector of the first NPN transistor Q1, the emitter of the PNP transistor Q3 is connected to the second end of the second capacitor C2, and the connection point between the base of the PNP transistor Q3 and the fifth resistor R5 is connected to the connection point between the emitter of the PNP transistor Q3 and the second capacitor C2 through the sixth resistor R6; the first end of the second capacitor C2 is connected to the cathode of the second diode D2, and the anode of the second diode D2 is connected to the connection point of the first capacitor C1 and the cathode of the first diode D1; the cathode of the third diode D3 is connected to the connection point of the second capacitor C2 and the emitter of the PNP transistor Q3, and the cathode of the third diode D3 is connected to the second end of the third capacitor C3 and grounded; the first end of the third capacitor C3 is connected to the connection point of the second capacitor C2 and the cathode of the second diode D2, and serves as an output end to supply power to the outside.

[0008] In an implementation of the present application, the first NPN transistor Q1, the first resistor R1, the second resistor R2, the second NPN transistor Q2, the third resistor R3, and the fourth resistor R4 constitute two groups of NPN transistor switch circuits.

[0009] In an implementation of the present application, the first control signal PWM_A controls the conduction of the first NPN transistor Q1, and the second control signal PWM_B controls the conduction of the second NPN transistor Q2. The first control signal PWM_A and the second control signal PWM_B are two complementary square wave drive signals.

[0010] In one implementation of the present application, the power supply VCC and the first diode D1 are the power supply ends of the first capacitor C1; when the first control signal PWM_A is at a high level, the first NPN transistor Q1 is turned on, and the power supply VCC forms a loop through the first diode D1, the first capacitor C1, the first NPN transistor Q1 and the ground GND to charge the first capacitor C1.

[0011] In one implementation of the present application, the PNP transistor Q3, the fifth resistor R5, and the sixth resistor R6 are a PNP transistor switching circuit. When the second control signal PWM_B is at a high level and the second NPN transistor Q2 is turned on, the base of the PNP transistor Q3 becomes a low level and the PNP transistor Q3 is turned on.

[0012] In one implementation of the present application, the first capacitor C1, the second diode D2, the second capacitor C2, and the PNP transistor Q3 constitute an energy transmission circuit; when the first NPN transistor Q1 is turned off and the second NPN transistor Q2 and the PNP transistor Q3 are turned on, the first capacitor C1 charges the second capacitor C2 through the first capacitor C1, the second diode D2, the second capacitor C2, and the PNP transistor Q3 circuit.

[0013] In an implementation of the present application, the second capacitor C2, the third capacitor C3, and the third diode D3 form an isolation circuit, so that the third capacitor C3 will not reversely charge the second capacitor C2 after being charged.

[0014] In an implementation of the present application, the negative electrode of the third capacitor C3 is isolated from the ground GND to achieve suspension of the power supply.

[0015] The embodiment of the present application provides a low-cost floating power supply circuit based on a switched capacitor, which has the following features:

[0016] Beneficial effects:

[0017] 1. Significant cost advantage: The floating power supply circuit of the present invention abandons the expensive isolation transformers, optocouplers and other devices in the traditional isolated power supply design, and instead adopts relatively low-priced basic electronic components such as diodes, transistors, capacitors and resistors. These components not only have low procurement costs, but are also widely available in the market and easy to obtain. Taking mass production as an example, compared with the traditional solution using an isolation transformer, the circuit of the present invention can reduce component costs by about 30%-50%, greatly reducing production costs, and providing an economical power supply solution for cost-sensitive application scenarios. In fields such as consumer electronics and small household appliances, it can effectively enhance the market competitiveness of products.

[0018] 2. The circuit structure is simple and easy to implement: The entire circuit architecture is designed based on the common switching capacitor principle, the components are clear, and the connection method and working logic between the components are easy to understand and master. Compared with the complex circuits that achieve isolation by traditional current limiting conduction methods, the circuit of the present invention does not require sophisticated and complex layout design and tedious parameter debugging. For electronic engineers, whether in the circuit design stage or in the subsequent production assembly and troubleshooting links, it can greatly save time and energy costs. Even engineers with relatively inexperienced experience can quickly get started with design and optimization, effectively shortening the product development cycle and improving production efficiency.

[0019] 3. Stable and reliable performance: The complementary square wave drive signals PWM_A and PWM_B are used to precisely control the conduction and cutoff of the NPN transistors Q1 and Q2, thereby realizing the charging and discharging process of the capacitor in an orderly manner, ensuring the stable transmission of energy. The isolation loop design in the circuit, that is, the structure composed of the second capacitor C2, the third capacitor C3 and the third diode D3, effectively prevents the reverse flow of current, ensures that the energy stored in the third capacitor C3 will not leak or reverse charge, and makes the output suspension power supply voltage stable and reliable, and can provide continuous and stable power supply to the load. In electronic equipment with high requirements on power supply stability, such as precision measuring instruments, communication base stations, etc., the suspension power supply circuit of the present invention can effectively reduce equipment failures or measurement errors caused by power supply fluctuations, and improve the overall performance and reliability of the equipment.

[0020] 4. Good isolation performance: The negative electrode of the third capacitor C3 is effectively isolated from the ground GND, successfully building a floating power supply. This isolation method can effectively block the electrical interference between different power supply networks, avoiding signal distortion, equipment failure and other problems caused by common ground interference. In medical equipment, it can prevent patients from the risk of electric shock and ensure patient safety; in industrial automation systems, it can ensure that signal transmission between different functional modules is not interfered with, improving the system's anti-interference ability and operational stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0022] Figure 1 A schematic diagram of the structure of a low-cost suspended power supply circuit based on a switched capacitor provided in an embodiment of the present application. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solution and advantages of the present application clearer, the technical solution of the present application will be clearly and completely described below in combination with the specific embodiments of the present application and the corresponding drawings. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present application.

[0024] The embodiment of the present application provides a low-cost floating power supply circuit based on a switched capacitor, which is used to solve the following technical problems: the conventional isolated power supply design circuit is complex and costly.

[0025] The technical solution proposed in the embodiments of the present application is described in detail below with reference to the accompanying drawings.

[0026] Figure 1 A schematic diagram of a low-cost floating power supply circuit structure based on a switched capacitor provided in an embodiment of the present application. Figure 1 As shown, a low-cost floating power supply circuit based on a switched capacitor provided in an embodiment of the present application includes: a power supply VCC, a first diode D1, a second diode D2, a third diode D3, a first NPN transistor Q1, a second NPN transistor Q2, a PNP transistor Q3, a first capacitor C1, a second capacitor C2, a third capacitor C3, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, and a sixth resistor R6.

[0027] The positive electrode of the power supply VCC is connected to the anode of the first diode D1, the cathode of the first diode D1 is connected to the first end of the first capacitor C1, the second end of the first capacitor C1 is connected to the collector of the first NPN transistor Q1, and the emitter of the first NPN transistor Q1 is grounded GND.

[0028] The base of the first NPN transistor Q1 is connected to the first control signal PWM_A through the first resistor R1 and is grounded through the second resistor R2; the base of the second NPN transistor Q2 is connected to the second control signal PWM_B through the third resistor R3 and is grounded through the fourth resistor R4.

[0029] The collector of the second NPN transistor Q2 is connected to the base of the PNP transistor Q3 through the fifth resistor R5; the collector of the PNP transistor Q3 is connected to the connection point between the first capacitor C1 and the collector of the first NPN transistor Q1, the emitter of the PNP transistor Q3 is connected to the second end of the second capacitor C2, and the connection point between the base of the PNP transistor Q3 and the fifth resistor R5 is connected to the connection point between the emitter of the PNP transistor Q3 and the second capacitor C2 through the sixth resistor R6.

[0030] A first end of the second capacitor C2 is connected to the cathode of the second diode D2 , and an anode of the second diode D2 is connected to a connection point between the first capacitor C1 and the cathode of the first diode D1 .

[0031] The cathode of the third diode D3 is connected to the connection point between the second capacitor C2 and the emitter of the PNP transistor Q3 , and the cathode of the third diode D3 is connected to the second end of the third capacitor C3 and is grounded.

[0032] A first end of the third capacitor C3 is connected to a connection point between the second capacitor C2 and the cathode of the second diode D2 and serves as an output end to supply power to the outside.

[0033] In one embodiment of the present application, a low-cost floating power supply circuit based on a switched capacitor specifically includes the following working process:

[0034] 1. Charging stage of the first capacitor C1: The first control signal PWM_A and the second control signal PWM_B are two complementary square wave drive signals. When the first control signal PWM_A is at a high level, the first NPN transistor Q1 is turned on. At this time, the power supply VCC, the first diode D1, the first capacitor C1, the first NPN transistor Q1 and the ground GND constitute a complete charging circuit. The current flows out from the positive electrode of the power supply VCC, passes through the first diode D1, and charges the first capacitor C1. Finally, the current flows back to the ground GND through the first NPN transistor Q1. In this process, the first diode D1 plays a role in preventing the current from flowing in the reverse direction, ensuring that the first capacitor C1 can be charged normally. The first resistor R1 is used to limit the current flowing into the base of the first NPN transistor Q1 to protect the transistor from being damaged by excessive current; the second resistor R2 provides a stable bias voltage for the base of the first NPN transistor Q1 to ensure that the transistor works in a suitable state.

[0035] 2. Energy transfer to the second capacitor C2 stage: When the first control signal PWM_A becomes a low level, the first NPN transistor Q1 is turned off; at the same time, the second control signal PWM_B becomes a high level, and the second NPN transistor Q2 is turned on. Since the second NPN transistor Q2 is turned on, its collector potential is pulled down, and the base potential of the PNP transistor Q3 is also turned to a low level through the fifth resistor R5. For the PNP transistor, when the base potential is lower than the emitter potential, the transistor is turned on, so the PNP transistor Q3 is turned on. At this time, the first capacitor C1, the second diode D2, the second capacitor C2, and the PNP transistor Q3 constitute an energy transmission loop. The electric energy stored in the first capacitor C1 is charged to the second capacitor C2 through this loop. The second diode D2 also plays a role in preventing the reverse flow of current, ensuring that energy can be transmitted unidirectionally from the first capacitor C1 to the second capacitor C2. The fifth resistor R5 limits the current flowing into the base of the PNP transistor Q3, and the sixth resistor R6 provides a suitable bias for the PNP transistor Q3 to ensure its stable conduction.

[0036] 3. Charging and isolation stage of the third capacitor C3: After the second capacitor C2 is charged, the third capacitor C3 is charged through the isolation loop formed by the second capacitor C2, the third capacitor C3, and the third diode D3. Due to the unidirectional conductivity of the third diode D3, when the third capacitor C3 is charged, the second capacitor C2 will not be reversely charged. At the same time, the negative electrode of the third capacitor C3 is isolated from the ground GND, thereby realizing the suspension of the power supply. The first end of the third capacitor C3 is used as the output end to supply power to the outside, providing a stable power supply for the subsequent load.

[0037] In one embodiment of the present application, the dead time setting is also included: during the switching process between the first NPN transistor Q1 and the second NPN transistor Q2, a certain dead time needs to be set. This is to prevent the first NPN transistor Q1 and the second NPN transistor Q2 from being turned on at the same time, because if they are turned on at the same time, the power supply VCC may be directly short-circuited through the first NPN transistor Q1 and the second NPN transistor Q2, which will not only damage the circuit components, but also affect the isolation effect of the entire circuit. By reasonably setting the dead time, the stable operation and safety of the circuit can be ensured.

[0038] In one embodiment of the present application, in actual application, the parameters of the circuit elements need to be selected according to the specific application scenario and design requirements. For example, for the first capacitor C1 and the second capacitor C2, the size of the capacitance value will affect the speed of charging and energy transmission. If fast charging and energy transmission are required, a capacitor with a larger capacitance value can be selected, but the volume and cost of the capacitor also need to be considered. For transistors Q1, Q2, and Q3, it is necessary to select a suitable model according to the operating voltage and current of the circuit to ensure that it can withstand the corresponding voltage and current. For resistors R1-R6, the size of their resistance values ​​will affect the bias and conduction of the transistors, and it is necessary to make a reasonable selection according to the characteristics of the transistors.

[0039] Through the above working process, the low-cost floating power supply circuit based on the switched capacitor provided in the embodiment of the present application can realize a low-cost, stable and reliable power suspension function, and meet the requirements of different electronic devices for isolated power supply.

[0040] Each embodiment in this application is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the IoT device and medium embodiments, since they are basically similar to the method embodiments, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiments.

[0041] The system and medium provided in the embodiments of the present application correspond one-to-one to the method. Therefore, the system and medium also have similar beneficial technical effects to the corresponding methods. Since the beneficial technical effects of the methods have been described in detail above, the beneficial technical effects of the system and medium will not be repeated here.

[0042] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that include computer-usable program code.

[0043] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0044] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture including an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0045] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0046] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0047] The memory may include non-permanent storage in a computer-readable medium, random access memory (RAM) and / or non-volatile memory in the form of read-only memory (ROM) or flash RAM. The memory is an example of a computer-readable medium.

[0048] Computer readable media include permanent and non-permanent, removable and non-removable media that can be implemented by any method or technology to store information. Information can be computer readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disk read-only memory (CD-ROM), digital versatile disk (DVD) or other optical storage, magnetic cassettes, magnetic tape magnetic disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer readable media does not include temporary computer readable media (transitory media), such as modulated data signals and carrier waves.

[0049] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0050] The above is only an embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.

Claims

1. A low-cost floating power supply circuit based on switched capacitors, characterized in that: include: Power supply VCC, first diode D1, second diode D2, third diode D3, first NPN transistor Q1, second NPN transistor Q2, PNP transistor Q3, first capacitor C1, second capacitor C2, third capacitor C3, first resistor R1, second resistor R2, third resistor R3, fourth resistor R4, fifth resistor R5, sixth resistor R6; The positive electrode of the power supply VCC is connected to the anode of the first diode D1, the cathode of the first diode D1 is connected to the first end of the first capacitor C1, the second end of the first capacitor C1 is connected to the collector of the first NPN transistor Q1, and the emitter of the first NPN transistor Q1 is grounded GND; The base of the first NPN transistor Q1 is connected to the first control signal PWM_A through the first resistor R1 and is grounded through the second resistor R2; the base of the second NPN transistor Q2 is connected to the second control signal PWM_B through the third resistor R3 and is grounded through the fourth resistor R4; The collector of the second NPN transistor Q2 is connected to the base of the PNP transistor Q3 through the fifth resistor R5; the collector of the PNP transistor Q3 is connected to the connection point between the first capacitor C1 and the collector of the first NPN transistor Q1, the emitter of the PNP transistor Q3 is connected to the second end of the second capacitor C2, and the connection point between the base of the PNP transistor Q3 and the fifth resistor R5 is connected to the connection point between the emitter of the PNP transistor Q3 and the second capacitor C2 through the sixth resistor R6; A first end of the second capacitor C2 is connected to the cathode of the second diode D2, and an anode of the second diode D2 is connected to a connection point between the first capacitor C1 and the cathode of the first diode D1; The cathode of the third diode D3 is connected to the connection point between the second capacitor C2 and the emitter of the PNP transistor Q3, and the cathode of the third diode D3 is connected to the second end of the third capacitor C3 and is grounded; A first end of the third capacitor C3 is connected to a connection point between the second capacitor C2 and the cathode of the second diode D2 and serves as an output end to supply power to the outside.

2. A low-cost floating power supply circuit based on switched capacitors according to claim 1, characterized in that: The first NPN transistor Q1, the first resistor R1, the second resistor R2, the second NPN transistor Q2, the third resistor R3, and the fourth resistor R4 form two groups of NPN transistor switch circuits.

3. A low-cost floating power supply circuit based on switched capacitors according to claim 1, characterized in that: The first control signal PWM_A controls the conduction of the first NPN transistor Q1 , and the second control signal PWM_B controls the conduction of the second NPN transistor Q2 . The first control signal PWM_A and the second control signal PWM_B are two complementary square wave driving signals.

4. A low-cost floating power supply circuit based on switched capacitors according to claim 1, characterized in that: The power supply VCC and the first diode D1 are the power supply terminals of the first capacitor C1; When the first control signal PWM_A is at a high level, the first NPN transistor Q1 is turned on, and the power source VCC forms a loop through the first diode D1, the first capacitor C1, the first NPN transistor Q1 and the ground GND to charge the first capacitor C1.

5. A low-cost floating power supply circuit based on switched capacitors according to claim 1, characterized in that: The PNP transistor Q3, the fifth resistor R5 and the sixth resistor R6 form a PNP transistor switch circuit. When the second control signal PWM_B is at a high level and the second NPN transistor Q2 is turned on, the base of the PNP transistor Q3 becomes a low level and the PNP transistor Q3 is turned on.

6. A low-cost floating power supply circuit based on switched capacitors according to claim 1, characterized in that: The first capacitor C1, the second diode D2, the second capacitor C2, and the PNP transistor Q3 form an energy transmission circuit; When the first NPN transistor Q1 is turned off and the second NPN transistor Q2 and the PNP transistor Q3 are turned on, the first capacitor C1 charges the second capacitor C2 through the first capacitor C1, the second diode D2, the second capacitor C2, and the PNP transistor Q3 loop.

7. A low-cost floating power supply circuit based on switched capacitors according to claim 1, characterized in that: The second capacitor C2, the third capacitor C3, and the third diode D3 form an isolation loop, so that the third capacitor C3 will not reversely charge the second capacitor C2 after being charged.

8. The low-cost floating power supply circuit based on switched capacitor according to claim 1, characterized in that: The negative electrode of the third capacitor C3 is isolated from the ground GND to achieve suspension of the power supply.

Images