A driving circuit and a switching power supply
By designing the drive circuits for the input signal processing unit, transformer isolation unit, and output signal processing unit, the problem of requiring complex isolation drive chips for switching power supplies was solved, achieving low-cost and reliable drive signal output.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SHENZHEN LIYUAN HAINA ENERGY CO LTD
- Filing Date
- 2025-07-29
- Publication Date
- 2026-06-19
AI Technical Summary
Existing switching power supplies require the use of complex and expensive dedicated isolation driver chips for isolation driving, resulting in high costs.
A driving circuit was designed, including an input signal processing unit, a transformer isolation unit, and an output signal processing unit. Electrical isolation is achieved through transformer isolation, and energy is discharged when the input signal is low level, which simplifies the circuit structure and reduces the cost.
A simple and low-cost drive circuit was implemented, which can provide a highly reliable drive signal for switching power supplies and reduce the cost of isolated drive for switching power supplies.
Smart Images
Figure CN224385356U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of power supply circuit technology, and particularly relates to a drive circuit and a switching power supply. Background Technology
[0002] Compared to traditional power frequency power supplies, switching power supplies offer advantages such as high operating frequency, high efficiency, light weight, high power density, step-up / step-down capability, high output power, and small size, leading to their widespread application in various fields. However, in scenarios requiring isolated driving of switching power supplies, complex and expensive dedicated isolation driver chips are often necessary. Therefore, designing a simple and low-cost driver circuit for switching power supplies has always been a key research focus for those skilled in the art. Utility Model Content
[0003] Therefore, the purpose of this utility model is to provide a driving circuit and a switching power supply, so as to fundamentally solve the problem that existing switching power supplies need to use complex and expensive dedicated isolation driving chips for isolation driving.
[0004] This utility model embodiment is implemented as follows: a driving circuit is provided, comprising:
[0005] An input signal processing unit is used to receive an input PWM signal and amplify the input PWM signal.
[0006] A transformer isolation unit, connected to the input signal processing unit, is used to receive a first signal output by the input signal processing unit and to electrically isolate the first signal; and
[0007] An output signal processing unit, connected to the transformer isolation unit, is used to receive the second signal output by the transformer isolation unit, amplify the second signal, and output a drive signal synchronized with the input PWM signal.
[0008] In some embodiments, the input signal processing unit includes:
[0009] The first signal amplification module is connected to the transformer isolation unit and is used to receive the input PWM signal and amplify the PWM signal.
[0010] The first energy discharge module is connected to the first signal amplification module and the transformer isolation unit respectively, and is used to discharge the energy output to the transformer isolation unit when the input PWM signal is low.
[0011] In some embodiments, the first signal amplification module includes a first transistor, a second transistor, a third transistor, a first resistor, a second resistor, a third resistor, a fourth resistor, a first diode, and a second diode; the first resistor is connected to the base of the first transistor, the anode of the first diode, and one end of the second resistor; the collector of the first transistor is connected to the base of the second transistor, the cathode of the first diode, and one end of the third resistor; the emitter of the first transistor is connected to the other end of the second resistor, the emitter of the second transistor, and the first energy discharge module; the collector of the second transistor is connected to the base of the third transistor, the first energy discharge module, and one end of the fourth resistor; the collector of the third transistor is connected to the other end of the third resistor, the other end of the fourth resistor, and the cathode of the second diode; the emitter of the third transistor is connected to the first energy discharge module, the anode of the second diode, and the transformer isolation unit.
[0012] In some embodiments, the first energy discharge module includes a fourth transistor and a third diode, the base of the fourth transistor being connected to the first signal amplification module; the emitter of the fourth transistor being connected to the first signal amplification module, the negative terminal of the third diode, and the transformer isolation unit, respectively; and the collector of the fourth transistor being connected to the first signal amplification module and the positive terminal of the third diode, respectively.
[0013] In some embodiments, the transformer isolation unit includes a transformer, the primary end of which is connected to the input signal processing unit, and the secondary end of which is connected to the output signal processing unit.
[0014] In some embodiments, the transformer isolation unit further includes a first capacitor and a second capacitor, the first capacitor being disposed between the input signal processing unit and the primary terminal of the transformer, and the second capacitor being disposed between the secondary terminal of the transformer and the output signal processing unit.
[0015] In some embodiments, the output signal processing unit includes:
[0016] The second signal amplification module is connected to the transformer isolation unit and is used to receive the second signal output by the transformer isolation unit, amplify the second signal, and output a drive signal synchronized with the input PWM signal.
[0017] The second energy discharge module, connected to the second signal amplification module, is used to discharge the energy output to the drive load when the drive signal is low.
[0018] In some embodiments, the second signal amplification module includes a fifth transistor, a sixth transistor, a seventh transistor, an eighth transistor, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a fourth diode, and a fifth diode; one end of the fifth resistor is connected to the transformer isolation unit; the other end of the fifth resistor is connected to the base of the fifth transistor, the anode of the fourth diode, and one end of the sixth resistor; the collector of the fifth transistor is connected to the base of the sixth transistor, the cathode of the fourth diode, and one end of the seventh resistor; the emitter of the fifth transistor is connected to the sixth... The other end of the resistor, the emitter of the sixth transistor, and the second energy discharge module; the collector of the sixth transistor is connected to the base of the seventh transistor, the second energy discharge module, and one end of the eighth resistor; the collector of the seventh transistor is connected to the other end of the seventh resistor, the other end of the eighth resistor, the collector of the eighth transistor, and the negative terminal of the fifth diode; the emitter of the seventh transistor is connected to the second energy discharge module and the base of the eighth transistor; the emitter of the eighth transistor is connected to the second energy discharge module and the positive terminal of the fifth diode.
[0019] In some embodiments, the second energy discharge module includes a ninth transistor, a thirteenth transistor, and a sixth diode; the base of the ninth transistor is connected to the second signal amplification module; the emitter of the ninth transistor is connected to both the second signal amplification module and the base of the thirteenth transistor; the collector of the ninth transistor is connected to the second signal amplification module, the collector of the thirteenth transistor, and the anode of the sixth diode; and the emitter of the thirteenth transistor is connected to both the second signal amplification module and the cathode of the sixth diode.
[0020] Another embodiment of the present invention provides a switching power supply, including the drive circuit described in any of the preceding embodiments.
[0021] This utility model provides a driving circuit and a switching power supply. When the input PWM signal received by the input signal processing unit is high, the input signal processing unit amplifies the input PWM signal and outputs a first signal to the transformer isolation unit. The transformer isolation unit electrically isolates the first signal and outputs a second signal to the output signal processing unit. The output signal processing unit amplifies the second signal and outputs a driving signal synchronized with the input PWM signal to drive the load. When the input PWM signal received by the input signal processing unit is low, the input signal processing unit, the transformer isolation unit, and the output signal processing unit sequentially perform energy coordination to turn the driving signal low, preparing for the next drive of the load. The driving circuit provided by this utility model is simple in design and low in cost, and can provide a highly reliable driving signal for the load. Attached Figure Description
[0022] Figure 1 This is a schematic diagram of the drive circuit provided in an embodiment of the present invention;
[0023] Figure 2 This is a circuit diagram of the driving circuit provided in an embodiment of the present invention. Detailed Implementation
[0024] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model. Furthermore, it should be understood that the specific embodiments described herein are merely for explaining this utility model and are not intended to limit this utility model.
[0025] In the description of this utility model, it should be understood that the terms "length", "width", "upper", "lower", "left", "right", "horizontal", "top", "bottom", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.
[0026] 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 number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.
[0027] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, a link, or a connection that allows for mutual communication; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.
[0028] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.
[0029] The following disclosure provides numerous different embodiments or examples for implementing various structures of the present invention. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the scope of the invention. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, examples of various specific processes and materials are provided in this invention, but those skilled in the art will recognize the application of other processes and / or the use of other materials.
[0030] refer to Figure 1 This utility model provides a driving circuit, including:
[0031] The input signal processing unit 100 is used to receive the input PWM signal and amplify the input PWM signal.
[0032] A transformer isolation unit 200, connected to the input signal processing unit 100, is used to receive a first signal output by the input signal processing unit 100 and electrically isolate the first signal; and
[0033] The output signal processing unit 300 is connected to the transformer isolation unit 200 and is used to receive the second signal output by the transformer isolation unit 200, amplify the second signal, and output a drive signal synchronized with the input PWM signal.
[0034] The drive circuit is used in the switching power supply. The input signal processing unit 100 is connected to the control chip, which generates an input PWM signal and outputs it to the input signal unit. The output signal processing unit 300 is connected to the power switching transistor, which outputs a drive signal to the power switching transistor. The power switching transistor turns on or off according to the drive signal, thereby controlling the energy conversion of the switching power supply. (Reference) Figure 2 In the diagram, PWM IN+ is the input PWM signal, and DRIVE OUT+ is the drive signal.
[0035] When the input PWM signal received by the input signal processing unit 100 is high, the input signal processing unit 100 amplifies the input PWM signal and outputs a first signal to the transformer isolation unit 200. The transformer isolation unit 200 electrically isolates the first signal and outputs a second signal to the output signal processing unit 300. The output signal processing unit 300 amplifies the second signal and outputs a drive signal synchronized with the input PWM signal to drive the load. When the input PWM signal received by the input signal processing unit 100 is low, the input signal processing unit 100, the transformer isolation unit 200, and the output signal processing unit 300 sequentially perform energy coordination to turn the drive signal low, preparing for the next drive of the load. The drive circuit provided by this utility model has a simple design and low cost, and can provide a highly reliable drive signal for the load.
[0036] In some specific embodiments of this application, the input signal processing unit 100 includes:
[0037] The first signal amplification module is connected to the transformer isolation unit 200 and is used to receive the input PWM signal and amplify the PWM signal.
[0038] The first energy discharge module is connected to the first signal amplification module and the transformer isolation unit 200 respectively, and is used to discharge the energy output to the transformer isolation unit 200 when the input PWM signal is low.
[0039] When the input PWM signal received by the input signal processing unit 100 is high, the input signal processing unit 100 amplifies the input PWM signal and outputs a first signal to the transformer isolation unit 200. When the PWM signal received by the input signal processing unit 100 is low, the first energy discharge module discharges the energy output to the transformer isolation unit 200.
[0040] refer to Figure 2 In some specific embodiments of this application, the first signal amplification module includes a first transistor Q1, a second transistor Q2, a third transistor Q3, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a first diode D1, and a second diode D2. The first resistor R1 is connected to the base of the first transistor Q1, the anode of the first diode D1, and one end of the second resistor R2. The collector of the first transistor Q1 is connected to the base of the second transistor Q2, the cathode of the first diode D1, and one end of the third resistor R3. The emitter of the first transistor Q1 is connected to the other end of the second resistor R2, the emitter of the second transistor Q2, and the first energy discharge module. The collector of the second transistor Q2 is connected to the base of the third transistor Q3, the first energy discharge module, and one end of the fourth resistor R4. The collector of the third transistor Q3 is connected to the other end of the third resistor R3, the other end of the fourth resistor R4, and the cathode of the second diode D2. The emitter of the third transistor Q3 is connected to the first energy discharge module, the anode of the second diode D2, and the transformer isolation unit 200.
[0041] Transistors Q1, Q2, and Q3 are all NPN transistors, serving functions such as switching logic control and current amplification. Resistor R1 acts as a current-limiting resistor for the base of transistor Q1. Resistor R2 protects transistor Q1 from electrostatic discharge (ESD) damage and prevents it from being falsely turned on when the input PWM signal is low. Resistor R3 acts as a current-limiting resistor for the collector of transistor Q1 and the base of transistor Q2, and also provides a bias voltage. Resistor R4 acts as a current-limiting resistor for the collector of transistor Q2 and the base of transistor Q3, and also provides a bias voltage. Diode D1 protects transistor Q1 from reverse voltage. Diode D2 clamps the ESD protection of transistor Q3.
[0042] refer to Figure 2In some specific embodiments of this application, the first energy discharge module includes a fourth transistor Q4 and a third diode D3. The base of the fourth transistor Q4 is connected to the first signal amplification module. The emitter of the fourth transistor Q4 is connected to the first signal amplification module, the cathode of the third diode D3, and the transformer isolation unit 200, respectively. The collector of the fourth transistor Q4 is connected to the first signal amplification module and the anode of the third diode D3, respectively.
[0043] The fourth transistor, Q4, is a PNP transistor. When the third transistor, Q3, is cut off, it quickly discharges the energy from the output capacitor. The third diode, D3, clamps the electrostatic discharge (ESD) voltage to protect the fourth transistor, Q4.
[0044] refer to Figure 2 In some specific embodiments of this application, the transformer isolation unit 200 includes a transformer T1, the primary end of which is connected to the input signal processing unit 100, and the secondary end of which is connected to the output signal processing unit 300.
[0045] The primary terminal of transformer T1 receives the first signal output by input signal processing unit 100. After electrical isolation of the first signal, it is output to output signal processing unit 300 through the secondary terminal.
[0046] refer to Figure 2 In some specific embodiments of this application, the transformer isolation unit 200 further includes a first capacitor C1 and a second capacitor C2. The first capacitor C1 is disposed between the input signal processing unit 100 and the primary terminal of the transformer T1, and the second capacitor C2 is disposed between the secondary terminal of the transformer T1 and the output signal processing unit 300.
[0047] The first capacitor C1 and the second capacitor C2 serve to block DC and allow AC signals to flow. The first capacitor C1 isolates the DC voltage signal from flowing to the primary winding of transformer T1, preventing excessive current and magnetic saturation, while allowing AC voltage signals to flow through the primary winding. The second capacitor C2 isolates the DC voltage signal from flowing through the secondary winding of transformer T1, while allowing AC voltage signals to flow through the secondary winding.
[0048] refer to Figure 2 In some specific embodiments of this application, the transformer isolation unit 200 further includes a ninth resistor R9 and a tenth resistor R10. The ninth resistor R9 is disposed between the first capacitor C1 and the primary terminal of the transformer T1, and the tenth resistor R10 is connected to the secondary terminal of the transformer T1.
[0049] The ninth resistor, R9, serves to limit the current. The tenth resistor, R10, is used to limit the voltage at the secondary end of transformer T1 and to provide a path for the magnetic balance and magnetic recovery at the primary end of transformer T1.
[0050] refer to Figure 2 In some specific embodiments of this application, the output signal processing unit 300 includes:
[0051] The second signal amplification module is connected to the transformer isolation unit 200, and is used to receive the second signal output by the transformer isolation unit 200, amplify the second signal, and output a drive signal synchronized with the input PWM signal;
[0052] The second energy discharge module, connected to the second signal amplification module, is used to discharge the energy output to the drive load when the drive signal is low.
[0053] When the second signal received by the second signal amplification module is at a high level, the second signal amplification module amplifies the second signal and outputs a drive signal synchronized with the input PWM signal. When the second signal received by the second signal amplification module is at a low level, the second energy discharge module discharges the energy output to the driven load.
[0054] refer to Figure 2 In some specific embodiments of this application, the second signal amplification module includes a fifth transistor Q5, a sixth transistor Q6, a seventh transistor Q7, an eighth transistor Q8, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a fourth diode D4, and a fifth diode D5. One end of the fifth resistor R5 is connected to the transformer isolation unit 200; the other end of the fifth resistor R5 is connected to the base of the fifth transistor Q5, the anode of the fourth diode D4, and one end of the sixth resistor R6; the collector of the fifth transistor Q5 is connected to the base of the sixth transistor Q6, the cathode of the fourth diode D4, and one end of the seventh resistor R7; the fifth transistor Q5... The emitter is connected to the other end of the sixth resistor R6, the emitter of the sixth transistor Q6, and the second energy discharge module, respectively; the collector of the sixth transistor Q6 is connected to the base of the seventh transistor Q7, the second energy discharge module, and one end of the eighth resistor R8, respectively; the collector of the seventh transistor Q7 is connected to the other end of the seventh resistor R7, the other end of the eighth resistor R8, the collector of the eighth transistor Q8, and the cathode of the fifth diode D5, respectively; the emitter of the seventh transistor Q7 is connected to the second energy discharge module and the base of the eighth transistor Q8, respectively; the emitter of the eighth transistor Q8 is connected to the second energy discharge module and the anode of the fifth diode D5, respectively.
[0055] Transistors Q5, Q6, Q7, and Q8 are all NPN transistors, serving functions such as switching logic control and current amplification. Resistor R5 acts as a current-limiting resistor for the base of transistor Q5. Resistor R6 protects transistor Q5 from electrostatic discharge damage and prevents it from being falsely turned on when the second signal is low. Resistor R7 acts as a current-limiting resistor for the collector of transistor Q6 and the base of transistor Q7, and also provides a bias voltage. Resistor R8 acts as a current-limiting resistor for the collector of transistor Q6 and the base of transistor Q7, and also provides a bias voltage. Diode D4 protects transistor Q5 from reverse voltage. Diode D5 clamps electrostatic discharge protection for transistor Q8.
[0056] refer to Figure 2 In some specific embodiments of this application, the second energy discharge module includes a ninth transistor Q9, a thirteenth transistor Q10, and a sixth diode D6. The base of the ninth transistor Q9 is connected to the second signal amplification module; the emitter of the ninth transistor Q9 is connected to both the second signal amplification module and the base of the thirteenth transistor Q10; the collector of the ninth transistor Q9 is connected to the second signal amplification module, the collector of the thirteenth transistor Q10, and the anode of the sixth diode D6; the emitter of the thirteenth transistor Q10 is connected to both the second signal amplification module and the cathode of the sixth diode D6.
[0057] Both transistors Q9 and Q10 are PNP transistors. When the second signal is low, they discharge the energy from the output to the drive load to -VCC1. Diode D6 clamps the electrostatic discharge protection of transistor Q10.
[0058] Based on the specific components of the first signal amplification module, the first energy discharge module, the transformer T1, the second signal amplification module, and the second energy discharge module, the circuit process is described in detail here.
[0059] After power-on VCC and VCC1, the first resistor R1 receives the input PWM signal. When the input PWM signal is high, it is current-limited by the first resistor R1 and passed to the base of the first transistor Q1, making it high. The first transistor Q1 turns on and pulls down the base of the second transistor Q2, causing the second transistor Q2 to turn off. The VCC voltage is current-limited by the fourth resistor R4 and flows into the bases of the third transistor Q3 and the fourth transistor Q4, making them high. After the third transistor Q3 turns on, it amplifies the VCC current and flows out of its emitter, through the first capacitor C1, the ninth resistor R9, and the primary terminal pins 1 and 2 of the transformer T1 to GND. At this time, the primary terminal pin 1 of the transformer T1 is high and the primary terminal pin 2 is low. At this time, the base and emitter of the fourth transistor Q4 are both high and cut off.
[0060] Next, transformer T1 performs energy transfer and electrical isolation. Since the secondary pin 4 and primary pin 1 of transformer T1 are in phase, the secondary pin 4 of transformer T1 outputs a high level. This high level is transmitted to the base of the fifth transistor Q5 through the second capacitor C2 and the fifth resistor R5, making it a high potential. The fifth transistor Q5 turns on and pulls down the base potential of the sixth transistor Q6, causing the sixth transistor Q6 to turn off. The VCC1 voltage is then limited by the eighth resistor R8 and flows into the base of the seventh transistor Q7 and the base of the ninth transistor Q9, making it a high potential. After the seventh transistor Q7 turns on, it amplifies the VCC1 current, which flows out of its emitter and into the base of the eighth transistor Q8 and the thirteenth transistor Q10, making them a high potential. After the eighth transistor Q8 turns on, it amplifies the VCC1 current again, which flows out of its emitter, making it a high potential. This serves as the drive output signal. At this time, the bases and emitters of the ninth transistor Q9 and the thirteenth transistor Q10 are both at high potentials and are turned off.
[0061] After power-on VCC and VCC1, the first resistor R1 receives the input PWM signal. When the input PWM signal is low, it is current-limited by the first resistor R1 and passed to the base of the first transistor Q1, making it low potential. The first transistor Q1 is cut off. VCC, after being current-limited by the third resistor R3, provides a bias voltage for the second transistor Q2. After the second transistor Q2 is turned on, it amplifies the VCC current and flows out of the second transistor Q2 to GND. The collector of the second transistor Q2, the base of the third transistor Q3, and the base of the fourth transistor Q4 are all low potential. The third transistor Q3 is cut off, and the fourth transistor Q4 is turned on. The energy of the output capacitor of the third transistor Q3 and the leakage inductance energy of the transformer isolation unit 200 are discharged to GND through the emitter of the second transistor Q2 and the collector of the fourth transistor Q4. At this time, the energy stored at the primary end of the transformer T1 is discharged to GND through pin 2. Pins 1 and 2 of the primary end of the transformer T1 are both low potential.
[0062] Next, transformer T1 performs energy transfer and electrical isolation. Since secondary pin 4 and primary pin 1 of transformer T1 are in phase, and secondary pin 3 and primary pin 2 are in phase, secondary pins 4 and 3 of transformer T1 are at low potential. The base of the fifth transistor Q5 is at a low potential and is cut off. VCC1 provides a bias voltage to the base of the sixth transistor Q6 through the seventh resistor R7. After the sixth transistor Q6 is turned on, it amplifies the current flowing from its emitter to -VCC1. The collector of the sixth transistor Q6, the primary pin 1, and the primary pin 2 are in phase. The bases of transistors Q7, Q8, Q9, and Q10 are all at low potentials. Transistors Q7 and Q8 are cut off, while transistors Q9 and Q10 are turned on. The stored energy is discharged to -VCC1 through the collectors of transistors Q9 and Q10 and the emitter of transistor Q6. At this time, the emitter of transistor Q8 and the drive signal are at low potentials, preparing for the next drive to turn on.
[0063] This utility model also provides a switching power supply, including the drive circuit described in any of the preceding embodiments. When the input PWM signal received by the input signal processing unit 100 is high, the input signal processing unit 100 amplifies the input PWM signal and outputs a first signal to the transformer isolation unit 200. The transformer isolation unit 200 electrically isolates the first signal and outputs a second signal to the output signal processing unit 300. The output signal processing unit 300 amplifies the second signal and outputs a drive signal synchronized with the input PWM signal to drive the load. When the input PWM signal received by the input signal processing unit 100 is low, the input signal processing unit 100, the transformer isolation unit 200, and the output signal processing unit 300 sequentially perform energy coordination to turn the drive signal low, preparing for the next drive of the load. The switching power supply provided by this utility model includes a drive circuit, is simple in design, low in cost, and can provide a highly reliable drive signal for the load.
[0064] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.
[0065] The above-described embodiments are merely illustrative of several implementations of this utility model, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this utility model. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the appended claims.
Claims
1. A driving circuit, characterized in that, include: An input signal processing unit is used to receive an input PWM signal and amplify the input PWM signal. A transformer isolation unit, connected to the input signal processing unit, is used to receive a first signal output by the input signal processing unit and to electrically isolate the first signal. as well as An output signal processing unit, connected to the transformer isolation unit, is used to receive the second signal output by the transformer isolation unit, amplify the second signal, and output a drive signal synchronized with the input PWM signal.
2. The driving circuit according to claim 1, characterized in that, The input signal processing unit includes: The first signal amplification module is connected to the transformer isolation unit and is used to receive the input PWM signal and amplify the PWM signal. The first energy discharge module is connected to the first signal amplification module and the transformer isolation unit respectively, and is used to discharge the energy output to the transformer isolation unit when the input PWM signal is low.
3. The driving circuit according to claim 2, characterized in that, The first signal amplification module includes a first transistor, a second transistor, a third transistor, a first resistor, a second resistor, a third resistor, a fourth resistor, a first diode, and a second diode. The first resistor is connected to the base of the first transistor, the anode of the first diode, and one end of the second resistor. The collector of the first transistor is connected to the base of the second transistor, the cathode of the first diode, and one end of the third resistor. The emitter of the first transistor is connected to the other end of the second resistor, the emitter of the second transistor, and the first energy discharge module. The collector of the second transistor is connected to the base of the third transistor, the first energy discharge module, and one end of the fourth resistor, respectively; the collector of the third transistor is connected to the other end of the third resistor, the other end of the fourth resistor, and the negative terminal of the second diode, respectively; the emitter of the third transistor is connected to the first energy discharge module, the positive terminal of the second diode, and the transformer isolation unit, respectively.
4. The driving circuit according to claim 2, characterized in that, The first energy discharge module includes a fourth transistor and a third diode; the base of the fourth transistor is connected to the first signal amplification module; the emitter of the fourth transistor is connected to the first signal amplification module, the negative terminal of the third diode, and the transformer isolation unit, respectively; the collector of the fourth transistor is connected to the first signal amplification module and the positive terminal of the third diode, respectively.
5. The driving circuit according to claim 1, characterized in that, The transformer isolation unit includes a transformer, the primary end of which is connected to the input signal processing unit, and the secondary end of which is connected to the output signal processing unit.
6. The driving circuit according to claim 5, characterized in that, The transformer isolation unit further includes a first capacitor and a second capacitor. The first capacitor is disposed between the input signal processing unit and the primary terminal of the transformer, and the second capacitor is disposed between the secondary terminal of the transformer and the output signal processing unit.
7. The driving circuit according to claim 1, characterized in that, The output signal processing unit includes: The second signal amplification module is connected to the transformer isolation unit and is used to receive the second signal output by the transformer isolation unit, amplify the second signal, and output a drive signal synchronized with the input PWM signal. The second energy discharge module, connected to the second signal amplification module, is used to discharge the energy output to the drive load when the drive signal is low.
8. The driving circuit according to claim 7, characterized in that, The second signal amplification module includes a fifth transistor, a sixth transistor, a seventh transistor, an eighth transistor, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a fourth diode, and a fifth diode. One end of the fifth resistor is connected to the transformer isolation unit, and the other end of the fifth resistor is connected to the base of the fifth transistor, the anode of the fourth diode, and one end of the sixth resistor. The collector of the fifth transistor is connected to the base of the sixth transistor, the cathode of the fourth diode, and one end of the seventh resistor. The emitter of the fifth transistor is connected to the other end of the sixth resistor. The emitter of the sixth transistor and the second energy discharge module are connected; the collector of the sixth transistor is connected to the base of the seventh transistor, the second energy discharge module and one end of the eighth resistor; the collector of the seventh transistor is connected to the other end of the seventh resistor, the other end of the eighth resistor, the collector of the eighth transistor and the negative terminal of the fifth diode; the emitter of the seventh transistor is connected to the second energy discharge module and the base of the eighth transistor; the emitter of the eighth transistor is connected to the second energy discharge module and the positive terminal of the fifth diode.
9. The driving circuit according to claim 7, characterized in that, The second energy discharge module includes a ninth transistor, a thirteenth transistor, and a sixth diode; the base of the ninth transistor is connected to the second signal amplification module; the emitter of the ninth transistor is connected to both the second signal amplification module and the base of the thirteenth transistor; the collector of the ninth transistor is connected to the second signal amplification module, the collector of the thirteenth transistor, and the anode of the sixth diode; and the emitter of the thirteenth transistor is connected to both the second signal amplification module and the cathode of the sixth diode.
10. A switching power supply, characterized in that, Includes the drive circuit as described in any one of claims 1-9.