A power supply circuit and a power supply method for improving an output loop of a power supply chip

Abstract

The application relates to the technical field of power supply circuits, and provides a low-cost power supply circuit and a power supply method for improving an output isolation driving circuit of a power supply chip, wherein the power supply circuit comprises a power supply circuit and an isolation driving circuit connected through signals, the power supply circuit comprises a voltage reduction unit and a bypass device, the isolation driving circuit comprises a transformer T1, a plurality of diodes and a plurality of output ends, a primary winding of the transformer T1 is provided with a first output end, the transformer T1 is provided with at least one secondary winding, each secondary winding is connected with one diode, and the output end of the diode is a second output end corresponding to the secondary winding. The application realizes the purposes of considering low cost, miniaturization and flexible expandability.

Description

Technical Field

[0001] This application relates to the technical field of power supply circuits, specifically to a power supply circuit and power supply method for improving the output circuit of a power chip. Background Technology

[0002] In power electronic converter drive systems, multiple isolated drive power supplies are often required to power the drive chips of power devices. Existing multi-channel isolated drive power supply solutions mainly fall into two categories: Solution 1: Each isolated drive circuit is configured with a separate isolated power conversion circuit. This method offers reliable isolation performance, but each circuit requires an independent transformer, rectifier, and controller, resulting in a large number of components, a large PCB footprint, and high material costs. Expanding the circuit requires adding a completely new power supply circuit, leading to extremely high expansion costs. Solution 2: A single transformer is used to fix multiple secondary-side pre-built isolated power supply modules. The number of secondary windings is fixed at the factory, making it impossible to flexibly add or remove output circuits. If additional drive channels are needed later, the power supply module must be replaced, resulting in poor versatility.

[0003] Meanwhile, in existing solutions, each of the multiple isolated driver power supplies has its own independent front-end buck circuit, resulting in redundant system components and low utilization of power chips. When the equipment requires multiple isolated drivers and there is a need for channel expansion in the future, traditional solutions struggle to balance low cost, miniaturization, and flexible scalability. Summary of the Invention

[0004] To address the challenge of achieving low cost, miniaturization, and flexible scalability in seamless solutions, this application provides a power supply circuit and method for improving the output isolation drive circuit of a power chip at a low cost.

[0005] In a first aspect, this application provides a low-cost power supply circuit for improving the output isolation drive circuit of a power chip, employing the following technical solution: A low-cost power supply circuit for improving the output isolation drive circuit of a power chip is disclosed. The circuit includes a power supply circuit and an isolation drive circuit connected by signals. The power supply circuit includes a step-down unit and a bypass device. The isolation drive circuit includes a transformer T1, multiple diodes, and multiple output terminals. The primary winding of the transformer T1 is provided with a first output terminal. The transformer T1 is provided with at least one secondary winding. Each secondary winding is connected to a diode, and the output terminal of the diode is the second output terminal corresponding to the secondary winding.

[0006] By adopting the above technical solution, the present invention divides the circuit into an electrically connected power supply circuit and an isolation drive circuit. The voltage is stepped down by the front-stage step-down unit to provide a stable power supply for the subsequent isolation drive circuit. A single transformer T1 is used to set up a primary winding and an expandable structure of multiple secondary windings, so that the electrical energy of the primary winding is transmitted to each secondary winding through electromagnetic coupling. Each secondary winding can be independently matched with a diode to complete the rectification and conversion. After rectification, each secondary winding independently forms a second output terminal.

[0007] This power supply circuit eliminates the need for separate power chips and independent transformers (T1) for each isolated drive circuit. The number of isolated drive circuits can be expanded simply by increasing the number of secondary windings and adding a small number of rectifier devices. This effectively reduces the number of core power supply components, lowers the hardware material cost and PCB footprint of the multi-channel isolated drive circuit, and solves the defects of traditional multi-channel isolated drive circuits, such as redundant components, large size, high cost, and poor scalability. While ensuring electrical isolation and independent operation of each output, it achieves a low-cost and flexibly expandable multi-channel isolated drive power supply architecture.

[0008] Preferably, the step-down unit includes a voltage conversion chip U1, a first voltage divider resistor R2, and a second voltage divider resistor R3. The first voltage divider resistor R2 is signal-connected to the voltage conversion chip U1, and the other end of the second voltage divider resistor R2 is grounded. One end of the second voltage divider resistor R3 is signal-connected to the end of the first voltage divider resistor R2 near the voltage conversion chip U1, and the other end of the second voltage divider resistor R3 is signal-connected to the primary winding of the transformer T1.

[0009] By adopting the above technical solution, a feedback voltage regulation network is formed by the voltage conversion chip in conjunction with the first voltage divider resistor and the second voltage divider resistor. The voltage divider resistor is grounded to form a reference potential and performs voltage sampling feedback on the voltage conversion chip. By changing the resistance ratio of the two voltage divider resistors, the feedback voltage of the voltage conversion chip can be changed in real time, so that the voltage conversion chip can dynamically adjust the output voltage and accurately regulate the input power supply voltage of the primary winding of transformer T1.

[0010] This voltage regulation structure eliminates the need for additional voltage regulation chips and control circuits. It achieves continuous adjustable output voltage by relying solely on hardware resistor-capacitor voltage division. The circuit structure is simple, with high voltage regulation accuracy and strong adaptability. It can flexibly adjust the overall output voltage level according to the voltage requirements of different drive loads, improving circuit versatility and debugging convenience, while reducing overall power consumption and hardware costs.

[0011] Preferably, the bypass device includes multiple capacitors, with the first capacitor C1 and the second capacitor C2 located at the input terminal of the buck unit, and the third capacitor C3 and the fourth capacitor C4 located at the output terminal of the buck unit.

[0012] By adopting the above technical solution, first and second capacitors are set at the input end of the buck unit to perform high-frequency filtering of the external input voltage, absorb voltage spikes and fluctuation interference, and purify the input power quality; third and fourth capacitors are set at the output end of the buck unit to stabilize the output voltage of the voltage conversion chip and suppress switching ripple.

[0013] By using a dual-side bypass filter design for both input and output, power supply disturbances, high-frequency noise, and voltage ripples can be effectively filtered out. This avoids the problem of unstable output caused by input voltage fluctuations and chip switching ripples, ensuring stable input and output voltages of the buck unit. It also reduces the probability of power supply jitter and malfunctions in the downstream transformer T1 and the driven load, significantly improving the overall circuit's anti-interference capability and long-term operational stability.

[0014] Preferably, both the first output terminal and the second output terminal are connected in parallel with a filter capacitor.

[0015] By adopting the above technical solution, filter capacitors are configured at the first output terminal of the primary winding of transformer T1 and the second output terminal of each secondary winding. The step-down output voltage and the multi-channel isolated output voltage after rectification are subjected to secondary smoothing and filtering, absorbing rectification pulsation, high-frequency harmonics and voltage spikes, and significantly reducing the ripple of each output voltage.

[0016] It effectively solves the problems of large waveform ripple and unstable output voltage after rectification of AC voltage coupled by transformer T1, so that each isolated drive output voltage has high precision, low ripple and high stability power supply characteristics, which meets the stringent power supply quality requirements of precision drive chips and power devices. At the same time, each output is independently filtered to avoid crosstalk between channels, further improving the independence and consistency of multi-channel isolated output.

[0017] Preferably, the diode is an uncontrolled rectifier diode.

[0018] By adopting the above technical solution, the entire isolated output circuit uses uncontrolled rectifier diodes for passive rectification. Utilizing the unidirectional conduction characteristic of the diodes, the alternating AC voltage output from the secondary winding is directly converted into a DC drive voltage, eliminating the need for switching transistors, drive signals, PWM control logic, and rectifier control circuits. This significantly simplifies the structure of the subsequent isolated output circuit, reduces the number of components, lowers circuit control complexity and failure rate. The passive rectifier structure offers high reliability, fast response, and extremely low cost. It can stably achieve AC-DC power conversion without the need for software algorithms, making it suitable for large-scale multi-channel isolated drive applications and effectively reducing production, debugging, and maintenance costs.

[0019] Preferably, the isolated drive output circuits share the same step-down unit for power supply.

[0020] By adopting the above technical solution, all isolated drive output circuits share the same set of step-down units and a single power chip for power supply, thus abandoning the traditional design method that requires multiple independent power supplies for multiple drive circuits.

[0021] By adopting a single power chip for unified step-down and a single transformer T1 for multi-channel isolated output, the redundant configuration of power chips, filtering devices, and voltage regulators is significantly reduced. This significantly reduces the PCB layout area, lowers the overall material cost and heat dissipation pressure, improves the utilization rate of power chips and the circuit integration, avoids the superimposed interference and power consumption accumulation caused by multiple power chips working at the same time, and makes the overall structure more compact, which is conducive to the miniaturization and lightweight design of equipment.

[0022] Secondly, this application provides a power supply method for the power supply circuit as described in the first aspect above, employing the following technical solution: A method for improving the power supply of a power chip output circuit, applied to the aforementioned power supply circuit, includes: The external voltage input to the power supply circuit is stepped down by the step-down unit, while the voltage ripple is reduced by the bypass device. The output voltage of the step-down unit is connected to the primary winding of transformer T1, and the energy is transferred to each secondary winding through magnetic coupling; The secondary winding outputs an AC voltage, which is rectified by a diode to obtain a multi-channel isolated DC voltage and then supplied to the outside through the output terminal. Adjust the number of secondary windings of transformer T1 according to load requirements to expand the isolation drive circuit.

[0023] By adopting the above technical solution, a power supply mode with single power input and multiple isolated drive outputs is achieved through a complete process of external voltage step-down regulation, transformer electromagnetic isolation coupling, passive rectification on the secondary side, multiple isolated outputs, and on-demand winding expansion. The front-end unified voltage regulation and filtering ensures a stable power supply reference, while the rear-end relies on transformer T1 magnetic isolation to achieve complete electrical isolation and no interference between each path. The number of drive channels can be flexibly increased or decreased by adding or removing the number of secondary windings. The entire power supply process requires no complex program control, has simple and reliable operating logic, high stability, and can adapt to multi-drive scenarios with different numbers of channels and different load types, significantly improving the circuit's versatility and scalability.

[0024] Preferably, when adding an isolation drive circuit, only the secondary winding of transformer T1, the matching diode, and the filter capacitor are added.

[0025] By adopting the above technical solution, when upgrading the isolated drive circuit, there is no need to add new core components such as voltage conversion chips, main transformers, and input filters. Only the secondary winding needs to be added to the existing transformer T1 core, along with corresponding rectifier diodes and filter capacitors, to complete the channel expansion. This greatly simplifies the circuit upgrade process, avoiding the problems of redesigning the power circuit, replacing transformer T1, and extensively modifying the PCB required by traditional solutions. It significantly reduces the hardware and modification costs of later iterations and upgrades, and significantly improves the maintainability and upgradeability of the equipment.

[0026] Preferably, adjusting the number of turns in the secondary winding changes the voltage at the corresponding output terminal to adapt to different drive loads.

[0027] By adopting the above technical solution, this invention allows for independent adjustment of the induced voltage amplitude on the secondary winding of any single path by adjusting the number of coil turns, thus achieving individually adjustable single-path isolated output voltage. It enables differentiated configuration of each output voltage to meet the rated voltage requirements of different driven loads, solving the problem of traditional multi-path isolated power supplies having uniform output voltages and being unable to adapt to various load specifications. This allows the same circuit to be compatible with multiple driving devices simultaneously, greatly expanding the circuit's applicable scenarios and improving equipment adaptability and compatibility.

[0028] Preferably, the resistance ratio of the voltage divider resistors in the step-down unit is adjusted to change the primary power supply voltage of transformer T1, and the isolation output voltage of each circuit is adjusted synchronously.

[0029] This invention, by adjusting the resistance ratio of the voltage divider resistors in the pre-stage step-down unit, can uniformly change the overall output voltage of the voltage conversion chip and synchronously adjust the primary input voltage of transformer T1, thereby achieving synchronous step-up and step-down of all secondary-side isolated output voltages. It enables unified overall calibration and batch adjustment of multiple isolated output voltages, eliminating the need for individual debugging and calibration of each channel, significantly simplifying production debugging processes, improving batch production efficiency, and ensuring high consistency of output voltage parameters across all channels, thus enhancing the synchronicity and operational stability of the multi-channel drive system.

[0030] In summary, one or more technical solutions provided in the embodiments of this application have at least the following technical effects or advantages: 1. By adopting a single-set step-down unit with a single transformer T1 multi-channel expandable secondary winding architecture, multiple isolated drive circuits share the front-stage step-down circuit. Adding a new drive channel only requires adding the secondary winding of transformer T1, rectifier diodes, and matching filter devices. There is no need to add additional power conversion core components, which significantly reduces the number of components, reduces the PCB footprint, and effectively reduces the material cost and hardware modification cost of the multi-channel isolated drive power supply system. It solves the problems of component redundancy, large size, and high expansion cost when expanding isolation circuits in traditional solutions.

[0031] 2. Based on transformer magnetic coupling, multiple output electrical isolation is achieved. Combined with a pre-stage voltage divider and regulator network, input and output dual-side bypass capacitors, and independent filtering structures for each output, it can simultaneously adjust all isolated output voltages through voltage divider resistors, or achieve independent voltage configuration for each output by adjusting the number of turns in the secondary winding. At the same time, it continuously suppresses voltage ripple and electromagnetic interference, ensuring stable power supply voltage and low ripple for each isolated driver. It is compatible with the power supply requirements of different power driver chips, and the circuit is easy to debug and highly versatile.

[0032] 3. By using uncontrolled rectifier diodes to achieve passive AC-DC conversion, no additional control drive circuit is required, the hardware architecture is simple and the operation is highly reliable; at the same time, a standardized power supply expansion method is provided, and the isolation drive circuit can be flexibly added or removed according to the number of load channels, which facilitates product hardware iteration and upgrades, and is suitable for industrial mass applications that drive multiple power devices such as frequency converters and energy storage converters. Attached Figure Description

[0033] Figure 1 This is a circuit diagram of Embodiment 1 of this application, wherein the secondary winding of transformer T1 is provided with two windings; Figure 2 This is a schematic diagram of the steps in Embodiment 2 of this application.

[0034] Reference numerals: 1. Power supply circuit; 11. Step-down unit; 12. Bypass device; 2. Isolation drive circuit. Detailed Implementation

[0035] To enable those skilled in the art to better understand the technical solutions in this specification, the technical solutions in the embodiments of this specification will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0036] In the description of the embodiments of this application, the words "for example" or "for instance" are used to indicate examples, illustrations, or explanations. Any embodiment or design that is described as "for example" or "for instance" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design options. Rather, the use of the words "for example" or "for instance" is intended to present the relevant concepts in a specific manner.

[0037] In the description of the embodiments of this application, the term "multiple" means two or more. For example, multiple systems means two or more systems, and multiple screen terminals means two or more screen terminals. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the indicated technical features. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature. The terms "comprising," "including," "having," and variations thereof all mean "including but not limited to," unless otherwise specifically emphasized.

[0038] Example 1 Reference Figure 1 This embodiment provides a power supply circuit that improves the output circuit of a power chip. The power supply circuit of the present invention will be described in detail below with reference to the specific circuit connection relationship. In this embodiment, the external input power supply is the industrial standard 24V DC voltage. The power supply circuit consists of two main parts: a power supply circuit 1 electrically connected to each other and an isolation drive circuit.

[0039] Specifically, the power supply circuit 1 includes a step-down unit 11 and a bypass device 12. The step-down unit 11 mainly consists of a voltage conversion chip U1, a first voltage divider resistor R2, and a second voltage divider resistor R3. The power input terminal of the voltage conversion chip U1 is connected to an external 24V DC power supply; one end of the first voltage divider resistor R2 is electrically connected to the feedback pin of the voltage conversion chip U1, and the other end of the first voltage divider resistor R2 is grounded to establish a stable potential reference. One end of the second voltage divider resistor R3 is connected to the common connection node between the first voltage divider resistor R2 and the feedback pin of the voltage conversion chip U1, and the other end of the second voltage divider resistor R3 is electrically connected to the isolation drive circuit. The voltage conversion chip U1 collects the voltage signal from the voltage divider network through the feedback pin. Operators can change the value of the feedback sampling voltage by changing or adjusting the resistance ratio of the first voltage divider resistor R2 and the second voltage divider resistor R3. The voltage conversion chip U1 dynamically adjusts the duty cycle of the internal switching transistor according to the sampling voltage, and finally realizes the continuously adjustable step-down output voltage. This allows for precise control of the input power supply voltage of the transformer primary winding, adapting to the power supply requirements of different drive loads.

[0040] The bypass device 12 includes a first capacitor C1, a second capacitor C2, a third capacitor C3, and a fourth capacitor C4. The first capacitor C1 and the second capacitor C2 are connected in parallel, and both capacitors are located at the input terminal of the voltage conversion chip U1. The first capacitor C1 and the second capacitor C2 form an input bypass filter network, which can absorb voltage spikes and high-frequency pulse interference in the external input voltage, suppress voltage fluctuations caused by the front-end power supply line, and prevent input disturbances from causing the operating point of the voltage conversion chip to shift or the output to be abnormal.

[0041] The third capacitor C3 and the fourth capacitor C4 are connected in parallel. Both capacitors are located at the output terminal of the voltage conversion chip U1 as output bypass capacitors. The third capacitor C3 and the fourth capacitor C4 are used to filter out the high-frequency voltage ripple generated during the switching operation of the voltage conversion chip, smooth the DC voltage after step-down, and deliver low-ripple stable power to the primary winding of the subsequent transformer T1, thereby reducing the interference of switching noise on the isolation drive circuit.

[0042] Furthermore, the isolation drive circuit consists of a transformer T1, several uncontrolled rectifier diodes, multiple sets of filter capacitors, and multiple output terminals. Transformer T1 is configured with one primary winding and at least one expandable secondary winding. The primary winding of transformer T1 has a first output terminal, which is connected in parallel with an independent filter capacitor to further stabilize the primary supply voltage and suppress voltage drift caused by dynamic load changes. The end of the second voltage divider resistor C3 furthest from the voltage conversion chip U1 is connected to the primary winding of transformer T1.

[0043] Each secondary winding on transformer T1 is independently matched with an uncontrolled rectifier diode. The AC voltage induced by the secondary winding is connected to the input terminal of the uncontrolled rectifier diode. Utilizing the diode's unidirectional conduction characteristic, passive uncontrolled rectification is achieved, directly converting alternating AC to pulsating DC without the need for additional drive control signals. The output terminal of the uncontrolled rectifier diode forms the second output terminal corresponding to that secondary winding. Each second output terminal is connected in parallel with a filter capacitor to filter out the AC pulsating component and high-frequency harmonics in the rectified voltage, further reducing output voltage ripple and ensuring stable isolated power supply voltages for each circuit.

[0044] In this circuit structure, all isolated drive output circuits share the same set of step-down unit 11 for power supply, eliminating the need to configure voltage conversion chips and matching input / output filter devices for each isolated drive channel separately.

[0045] The power supply circuit operates as follows: A 24V external DC voltage is input, filtered and purified by the first capacitor C1 and the second capacitor C2, and then sent to the voltage conversion chip U1. The voltage conversion chip U1 performs DC-DC step-down conversion, and the stepped-down voltage is further regulated and filtered by the third capacitor C3 and the fourth capacitor C4 to obtain a low-ripple DC voltage. This DC voltage is then supplied to the primary winding of transformer T1 through the second voltage divider resistor R3. After the primary winding is energized, it forms an alternating excitation magnetic field, which, through electromagnetic coupling, transfers energy to each secondary winding of transformer T1 under electrical isolation. Each secondary winding induces an AC voltage, which is fed into the corresponding uncontrolled rectifier diode to complete the AC-DC conversion. The rectified voltage is smoothed by the output filter capacitor and finally provides an electrically isolated DC drive power supply to each driver chip and power device through multiple independent second output terminals.

[0046] In terms of hardware expansion and voltage adjustment, when a new isolated drive circuit needs to be added to the system, there is no need to replace the main body of transformer T1 or add a new voltage conversion chip U1. Only a new set of secondary windings needs to be wound onto the core of transformer T1, along with an uncontrolled rectifier diode and an output filter capacitor, to build a completely new isolated drive channel. Voltage regulation has two implementation methods: When simultaneously adjusting all isolated output voltages, the resistance ratio of the first voltage divider resistor R2 and the second voltage divider resistor R3 is adjusted to change the input voltage of the primary winding of transformer T1, achieving synchronous rise and fall of all secondary output voltages. When adjusting a single isolated output voltage, the number of turns of the corresponding secondary winding is adjusted to change the amplitude of the induced voltage in that secondary winding, enabling independent setting of the single output voltage. This allows for compatibility with various drive devices with different rated power supplies, achieving a balance between low cost, miniaturization, and flexible expandability.

[0047] Example 2 Reference Figure 2 This embodiment provides a power supply method to improve the output circuit of a power chip. This power supply method is applied to the power supply circuit described in Embodiment 1. The power supply method includes a complete power supply operation process as well as a circuit expansion and voltage regulation operation process.

[0048] Step S1: An external DC voltage is input to the step-down unit 11 within the power supply circuit 1. The voltage conversion chip performs DC step-down processing on the input voltage. Simultaneously, bypass capacitors located at the input and output terminals of the step-down unit 11 continuously perform filtering, absorbing voltage spikes, suppressing switching ripple and line voltage disturbances, and continuously outputting a stable DC voltage, which is then delivered to the primary winding of transformer T1. The bypass capacitors continuously filter and purify the input and output power in real time, ensuring that the output voltage of the step-down unit 11 does not fluctuate significantly, thus providing a stable energy input foundation for transformer T1.

[0049] Step S2: The stable DC voltage output by the step-down unit 11 is continuously connected to the primary winding of the transformer T1. The primary winding generates an alternating magnetic field. Based on the transformer magnetic coupling principle, the power is isolated and transmitted to each set of secondary windings of the transformer T1 under the condition that there is no direct electrical connection between the primary winding and the secondary winding. This achieves electrical isolation between the input side and each output side, avoiding the problems of crosstalk and potential interference between different drive circuits.

[0050] Step S3: Each secondary winding of transformer T1 induces an AC voltage. The AC voltage output from each secondary winding is sent to the corresponding uncontrolled rectifier diode. Relying on the unidirectional conduction characteristic of the diode, passive rectification is completed to convert AC power into DC power, resulting in multiple electrically isolated DC voltages. After the rectified DC voltage is further smoothed and regulated by the output filter capacitor, it is continuously supplied to the external drive load through each output terminal to meet the power supply requirements of the multi-channel power device drive chip.

[0051] Step S4: Based on the number of drive channels required by the overall load, flexibly increase or decrease the number of secondary windings of transformer T1 to expand and build the isolated drive circuit.

[0052] The specific operation method of the newly added isolation drive circuit is as follows: only a secondary winding is added to the original transformer T1 core, and corresponding rectifier diodes and output filter capacitors are added at the same time. No new step-down chip is required, and no redesign of the front-end power supply circuit is required, so as to complete the channel expansion with the fewest new components.

[0053] This method sets up two types of voltage regulation means to adapt to different debugging needs.

[0054] The first adjustment method is to adjust the number of turns of any secondary winding individually, change the amplitude of the electromagnetic induction voltage of that secondary winding, and independently adjust the power supply voltage of the isolation output terminal of that winding, so as to realize the differentiated setting of multiple output voltages and adapt to drive loads of various voltage levels at the same time.

[0055] The second adjustment method is to adjust the resistance ratio of the first voltage divider resistor R2 and the second voltage divider resistor R3 inside the step-down unit 11, change the output voltage of the voltage conversion chip U1, and synchronously adjust the supply voltage of the primary winding of the transformer T1, thereby uniformly adjusting the output voltage of all isolated output circuits. This facilitates batch uniform calibration of voltage parameters for the entire machine and simplifies the production line debugging process.

[0056] The entire power supply method relies on pure hardware circuits to achieve power conversion, isolation, and multiple outputs. It does not require complex control devices such as main control chips and PWM drive signals. The operating logic is stable and reliable, and the workload of circuit expansion and modification is small. It is suitable for power electronic equipment that requires multiple isolated drive power supplies, such as frequency converters, energy storage converters, and high-power motor drive devices.

[0057] This application is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not described in this disclosure. The specification and embodiments are to be considered exemplary only, and the scope and spirit of this disclosure are defined by the claims.

Claims

1. A power supply circuit for improving the output isolation drive circuit of a power chip at low cost, characterized in that, The power supply circuit includes a power supply circuit (1) for signal connection and an isolation drive circuit. The power supply circuit (1) includes a step-down unit (11) and a bypass device (12). The isolation drive circuit includes a transformer T1, multiple diodes and multiple output terminals. The primary winding of the transformer T1 is provided with a first output terminal. The transformer T1 is provided with at least one secondary winding. Each secondary winding is connected to a diode. The output terminal of the diode is the second output terminal corresponding to the secondary winding.

2. The power supply circuit for improving the output isolation drive circuit of a power chip according to claim 1, characterized in that, The step-down unit (11) includes a voltage conversion chip U1, a first voltage divider resistor R2, and a second voltage divider resistor R3. The first voltage divider resistor R2 is connected to the voltage conversion chip U1, and the other end of the second voltage divider resistor R2 is grounded. One end of the second voltage divider resistor R3 is connected to the end of the first voltage divider resistor R2 near the voltage conversion chip U1, and the other end of the second voltage divider resistor R3 is connected to the primary winding of the transformer T1.

3. The power supply circuit for improving the output isolation drive circuit of a power chip according to claim 1, characterized in that, The bypass device (12) includes multiple capacitors, with the first capacitor C1 and the second capacitor C2 located at the input terminal of the step-down unit (11), and the third capacitor C3 and the fourth capacitor C4 located at the output terminal of the step-down unit (11).

4. The power supply circuit for improving the output isolation drive circuit of the power chip according to claim 1, characterized in that, Both the first output terminal and the second output terminal are connected in parallel with filter capacitors.

5. The power supply circuit for improving the output isolation drive circuit of a power chip according to claim 1, characterized in that, The diode is an uncontrolled rectifier diode.

6. The power supply circuit for improving the output isolation drive circuit of a power chip according to claim 1, characterized in that, The isolated drive output circuits share the same step-down unit (11) for power supply.

7. A method for improving the power supply of a power chip output circuit, characterized in that, Applied to the power supply circuit according to any one of claims 1 to 6, comprising: The external voltage is input to the step-down unit (11) of the power supply circuit (1) for step-down processing, while the voltage ripple is reduced by the bypass device (12); The output voltage of the step-down unit (11) is connected to the primary winding of transformer T1, and the energy is transferred to each secondary winding through magnetic coupling; The secondary winding outputs an AC voltage, which is rectified by a diode to obtain a multi-channel isolated DC voltage and then supplied to the outside through the output terminal. Adjust the number of secondary windings of transformer T1 according to load requirements to expand the isolation drive circuit.

8. The method for improving the power supply of the output circuit of a power chip according to claim 7, characterized in that, When adding a new isolated drive circuit, only the secondary winding of transformer T1, the matching diode, and the filter capacitor need to be added.

9. The method for improving the power supply of the output circuit of a power chip according to claim 7, characterized in that, Adjusting the number of turns in the secondary winding changes the voltage at the corresponding output terminal, adapting to different drive loads.

10. The method for improving the power supply of the output circuit of a power chip according to claim 7, characterized in that, Adjust the resistance ratio of the voltage divider resistors in the step-down unit (11) to change the primary power supply voltage of transformer T1 and simultaneously adjust the isolation output voltage of each circuit.

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