Switching power supply circuit with wide voltage input
By connecting the switching tube Q1 in series with the built-in MOS tube of the main control chip U1 in the switching power supply, combined with the RCD peak absorption and voltage stabilization protection module, the stability problem of the switching power supply in a wide voltage environment is solved, and efficient voltage conversion and low-cost power supply circuit design are achieved.
Patent Information
- Application Number
- CN202422837433.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-20
- Publication Date
- 2025-10-17
- Estimated Expiration
- 2034-11-20
AI Technical Summary
Existing switching power supplies are difficult to operate stably in a wide voltage environment. Traditional solutions require the use of high-voltage components, which results in high cost and large size, and low economic efficiency.
By connecting the switch tube Q1 in series with the built-in MOS tube of the main control chip U1, combining the RCD peak absorption module and the voltage stabilization protection module, the voltage resistance and stability of the switching power supply are improved, and the main control chip U1 is used to control the switch state to achieve efficient voltage conversion.
The voltage resistance of the switching power supply is improved, the scope of use is expanded, the applicability and reliability are increased, the cost is reduced, the energy loss is reduced and the service life is extended.
Smart Images
Figure CN223451813U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model belongs to switching power supply technical field, concretely relates to a switching power supply circuit of wide voltage input. BACKGROUND
[0002] Switching power supply, also known as switching power supply, switching converter, is a kind of high-frequency power conversion device, is a kind of power supply unit. Its function is to convert the voltage of one level into the voltage or current required by user end through different forms of architecture. The input of switching power supply is mostly alternating current (for example, mains) or direct current, and the output is mostly the device requiring direct current.
[0003] At present, the existing switching power supply, usually its voltage application range is limited, it is difficult to work stably in wide voltage environment, in order to cope with high voltage input condition, traditional switching power supply often selects high-voltage component, and its cost is higher and the size is larger, and the economy is lower. INVENTION CONTENTS
[0004] In view of the above problems in the prior art, the utility model aims at providing a switching power supply circuit of wide voltage input, which improves the voltage resistance of the switching power supply by connecting the switching tube Q1 and the built-in MOS tube of the main control chip U1 in series, improves the voltage resistance degree of the switching power supply circuit by fewer components and lower cost, improves the cost-effectiveness of the circuit, expands the use range of the switching power supply circuit, and increases the applicability and reliability of the circuit.
[0005] A switching power supply circuit of wide voltage input, comprising a transformer T1, a switching tube Q1 and a main control chip U1, the main control chip U1 is built-in with a MOS tube, the switching tube Q1 is connected in series with the built-in MOS tube of the main control chip U1, and the main control chip U1 is used to control the switching state of the MOS tube and the switching tube Q1, so as to control the connection or disconnection of the input voltage of the primary winding of the transformer T1, and further control the output of the secondary winding of the transformer T1.
[0006] When the MOS tube and the switching tube Q1 are turned on, the input voltage is loaded to the primary winding of the transformer T1, and at this time, the output induced voltage of the secondary winding of the transformer T1 is used to power the load. When the MOS tube and the switching tube Q1 are turned off, the input voltage is loaded to the two ends of the switching tube Q1 and the MOS tube of the main control chip U1.
[0007] Preferably, the voltage stabilizing protection module comprises a resistor R3, a resistor R4, a resistor R5, a resistor R6, a resistor R7, a voltage stabilizing diode ZD1 and a diode TVS1, the resistor R3, the resistor R4, the resistor R5, the resistor R6 and the resistor R7 are connected in series, one end of the resistor R3 is connected to the VIN end of the switching power supply circuit, one end of the resistor R7 is connected to the diode TVS1, the other end of the diode TVS1 is grounded, the circuit between the resistor R6 and the resistor R7 is connected to the gate of the switching tube Q1, and the gate and the source of the switching tube Q1 are connected to the two ends of the voltage stabilizing diode ZD1.
[0008] Preferably, the RCD peak absorption module comprises a resistor R12, a resistor R8, a resistor R9, a capacitor C6, a diode D1 and a diode D2, the resistor R12, the resistor R8 and the capacitor C6 are connected in parallel, one end of the RCD peak absorption module is connected to the VIN end of the circuit, the other end of the RCD peak absorption module is connected to the resistor R9, the diode D1 and the diode D2 which are connected in series, and the other end of the diode D2 is connected to the drain of the switching tube Q1 and the primary winding of the transformer T1.
[0009] Preferably, the output filtering module comprises a capacitor C7 and a rectifier diode D3, the capacitor C7 is connected to the two ends of the secondary winding of the transformer T1, and one end of the rectifier diode D3 is connected to the VO- end of the secondary winding of the transformer T1 and the other end is grounded.
[0010] Preferably, the input processing module comprises a resistor R1, a resistor R2, a capacitor C1 and a capacitor C2, the capacitor C1 and the capacitor C2 are connected in series to the VIN end of the switching power supply circuit and grounded at the other end, the resistor R1 is connected in parallel to the capacitor C1, and the resistor R2 is connected in parallel to the capacitor C2.
[0011] Preferably, the main control chip U1 is connected with a capacitor C5, a resistor R10 and a resistor R11, the capacitor C5 is used for providing stable working current for the main control chip U1, and the resistor R10 and the resistor R11 form a voltage dividing network for providing feedback voltage for the main control chip U1.
[0012] Preferably, the voltage resistance value of the switching power supply circuit is the sum of the voltage resistance value of the switching tube Q1 and the voltage resistance value of the built-in MOS tube of the main control chip U1.
[0013] The switching power supply circuit with wide voltage input has the advantages that the switching tube Q1 and the built-in MOS tube of the main control chip U1 are connected in series to improve the voltage resistance of the switching power supply, the voltage resistance of the switching power supply circuit is improved by using fewer components and lower cost, the cost-effectiveness of the circuit is improved, the use range of the switching power supply circuit is expanded, and the applicability and reliability of the circuit are improved.
[0014] Through the circuit design of the RCD peak absorption module and the voltage stabilizing protection module, the absorption of transient high-frequency peak voltage is realized, and the gate voltage of the switch tube Q1 is limited, thereby improving the stability and anti-interference performance of the whole circuit.
[0015] In addition, the switch control is realized through the master control chip U1, and compared with a linear power supply, the power switch circuit has higher efficiency and lower energy loss, reduces heat generation, and is beneficial to prolong the service life. BRIEF DESCRIPTION OF DRAWINGS
[0016] The accompanying drawings are included to provide a further understanding of the present application, and constitute a part of the specification, illustrate the present application and are used to explain the present application, and do not constitute a limitation on the present application. In the drawings:
[0017] Figure 1 is a circuit diagram of the present application. DETAILED DESCRIPTION
[0018] Embodiment one
[0019] As shown in Figure 1 , a wide voltage input switch power supply circuit, comprising an input processing module, a voltage stabilizing protection module, a switch tube Q1, a master control module, an RCD peak absorption module, a transformer T1 and an output filter module.
[0020] The master control module comprises a master control chip U1, a capacitor C5, a resistor R10 and a resistor R11, wherein the model of the master control chip U1 in the embodiment is LNK623DG, and the built-in MOS tube of the master control chip U1 is connected in series with the switch tube Q1. When the switch power supply circuit is normally working, the switch state of the built-in MOS tube of the master control chip U1 and the switch tube Q1 is controlled by the master control chip U1, so as to control the connection or disconnection of the input voltage of the primary winding of the transformer T1, and the high-frequency switch control of the switch power supply circuit is realized through the master control chip U1, so as to adjust the power transmission, realize efficient voltage conversion and stable output.
[0021] In addition, as shown in Figure 1 , the capacitor C5 is connected with the master control chip U1, and is used for providing stable working current for the master control chip U1; the resistor R10 and the resistor R11 constitute a voltage dividing network, which is used for providing feedback voltage for the master control chip U1, so as to facilitate the master control chip U1 to adjust the switching frequency and duty cycle, and improve the stability of the circuit.
[0022] As shown in Figure 1As shown, the input processing module includes resistors R1, R2, capacitors C1 and C2. Specifically, capacitors C1 and C2 are connected in series to the VIN terminal of the switching power supply circuit, and the other end is grounded. Resistors R1 and R2 are connected in parallel with capacitors C1 and C2, respectively. The series connection of capacitors C1 and C2 can increase the voltage resistance of the filter capacitor, and resistors R1 and R2 are used to balance the voltage of capacitors C1 and C2. By the mutual cooperation between the resistor and the capacitor, the high-frequency noise of the input voltage is suppressed, and voltage balancing is achieved.
[0023] The voltage stabilizing protection module is used to provide a stable bias voltage for the switching tube Q1 and prevent the input voltage transient from affecting the circuit.
[0024] As shown in Figure 1 The voltage stabilizing protection module includes resistors R3, R4, R5, R6, R7, a voltage stabilizing diode ZD1, and a diode TVS1. Specifically, resistors R3, R4, R5, R6, and R7 are connected in series, one end of resistor R3 is connected to the VIN terminal of the switching power supply circuit, one end of resistor R7 is connected to diode TVS1, the other end of diode TVS1 is grounded, the circuit between resistors R6 and R7 is connected to the gate of switching tube Q1, and the gate and source of switching tube Q1 are connected to the two ends of voltage stabilizing diode ZD1, respectively, for limiting the gate voltage and preventing the gate voltage from being too high to damage the switching tube Q1.
[0025] Among them, resistors R3, R4, R5, and R6 serve as the gate bias resistors of switching tube Q1, providing a bias voltage for switching tube Q1, so that switching tube Q1 can stabilize switching when working. Resistor R7 serves as the gate discharge resistor of switching tube Q1, providing a discharge channel when the gate voltage switches from high to low during the switching process of switching tube Q1, ensuring that the gate charge can be quickly discharged, which is beneficial to prevent the gate from being suspended and ensure that switching tube Q1 can be completely turned off when it is turned off, avoiding the misdirecting or incomplete conduction of switching tube Q1, thereby reducing loss and heat, increasing the reliability of switching.
[0026] Because high-frequency peak voltage is generated during the switching of switching tube Q1, especially during the switching process caused by the leakage inductance of transformer T1, it is necessary to configure an RCD peak absorption module to absorb high-frequency peak voltage through the mutual cooperation between the resistor, capacitor, and diode, avoid damage to switching tube Q1 and main control chip U1 caused by peak voltage, improve voltage stability, and prolong the service life of the circuit.
[0027] Specifically, as shown in Figure 1As shown, the RCD spike absorption module includes a resistor R12, a resistor R8, a resistor R9, a capacitor C6, a diode D1, and a diode D2, wherein the resistor R12, the resistor R8, and the capacitor C6 are connected in parallel, one end of which is connected to the VIN end of the circuit, and the other end is connected to the resistor R9, the diode D1, and the diode D2 in sequence, and the other end of the diode D2 is connected to the drain of the switch tube Q1 and the primary winding of the transformer T1.
[0028] The output filter module includes a capacitor C7 and a rectifier diode D3 connected to the secondary winding of the transformer T1, wherein the two ends of the capacitor C7 are respectively connected to the two ends of the secondary winding of the transformer T1, and the rectifier diode D3 is connected to the VO- end of the secondary winding of the transformer T1 at one end and grounded at the other end; the output filter module is used to rectify and smooth the voltage output by the transformer T1, which is conducive to outputting stable DC power to the load.
[0029] Working principle: when the wide voltage input switching power supply circuit is used, the input voltage is connected to the VIN end of the switching power supply circuit, and the input voltage is first suppressed by the input processing module to suppress high-frequency noise and stabilize the voltage, and the filtered voltage is loaded to the drain and gate of the switch tube Q1. At this time, the built-in MOS tube and the switch tube Q of the main control chip U1 are controlled to realize the connection or disconnection of the primary winding of the transformer T1.
[0030] When the main control chip U1 controls the built-in MOS tube and the switch tube Q1 to be turned on, the input voltage is loaded to the primary winding of the transformer T1, and the secondary winding of the transformer T1 outputs an induced voltage through the working principle of the transformer T1. After the induced voltage is filtered and stabilized by the output filter module, a stable DC output is formed for supplying the load.
[0031] When the main control chip U1 controls the built-in MOS tube and the switch tube Q1 to be turned off, the input voltage is loaded to the two ends of the switch tube Q1 and the MOS tube of the main control chip U1. Since the switch tube Q1 and the MOS tube are connected in series, the withstand voltage of the entire switching circuit is the sum of the withstand voltage of the switch tube Q1 and the withstand voltage of the MOS tube. In this embodiment, the withstand voltage of the switch tube Q1 selected is 600V, and the withstand voltage of the MOS tube built in the main control chip U1 is 700V, so the withstand voltage of the entire switching power supply circuit is about 1300V. Therefore, the input voltage of the switching power supply circuit can reach AC400V / DC600V.
[0032] In addition, in the switching process of the switch tube Q1, the high-frequency peak voltage generated in the circuit is absorbed by the RCD peak absorption module, the voltage stability is improved, and the switch tube Q1 and the main control chip U1 are prevented from being damaged by the peak voltage.
[0033] The above merely describes preferred embodiments of the present application and is not intended to limit the present application, and although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions recorded in the foregoing embodiments or equivalently replace some technical features. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.
Claims
1. A switching power supply circuit with a wide voltage input, characterized in that: It includes a transformer T1, a switch tube Q1 and a main control chip U1. The main control chip U1 has a built-in MOS tube. The switch tube Q1 is connected in series with the built-in MOS tube of the main control chip U1. The main control chip U1 is used to control the switching state of the MOS tube and the switch tube Q1 to control the connection or disconnection of the input voltage of the primary winding of the transformer T1, thereby controlling the output of the secondary winding of the transformer T1; When the MOS tube and the switch tube Q1 are turned on, the input voltage is loaded onto the primary winding of the transformer T1. At this time, the secondary winding of the transformer T1 outputs the induced voltage to power the load; when the MOS tube and the switch tube Q1 are turned off, the input voltage is loaded onto both ends of the switch tube Q1 and the MOS tube of the main control chip U1.
2. The switching power supply circuit with wide voltage input according to claim 1, characterized in that: It also includes a voltage stabilizing protection module, which includes a resistor R3, a resistor R4, a resistor R5, a resistor R6, a resistor R7, a voltage stabilizing diode ZD1, and a diode TVS1. The resistors R3, R4, R5, R6, and R7 are connected in series in sequence. One end of the resistor R3 is connected to the VIN end of the switching power supply circuit, one end of the resistor R7 is connected to the diode TVS1, and the other end of the diode TVS1 is grounded. The circuit between the resistors R6 and R7 is connected to the gate of the switch tube Q1, and the gate and source of the switch tube Q1 are respectively connected to the two ends of the voltage stabilizing diode ZD1.
3. The switching power supply circuit with wide voltage input according to claim 1, characterized in that: It also includes an RCD peak absorption module, which includes a resistor R12, a resistor R8, a resistor R9, a capacitor C6, a diode D1, and a diode D2. The resistor R12, the resistor R8, and the capacitor C6 are connected in parallel, one end of which is connected to the VIN end of the circuit, and the other end is connected to the resistor R9, the diode D1, and the diode D2 connected in series in sequence. The other end of the diode D2 is connected to the drain of the switch tube Q1 and is connected to the primary winding of the transformer T1.
4. The switching power supply circuit with wide voltage input according to claim 1, characterized in that: It also includes an output filter module, which includes a capacitor C7 and a rectifier diode D3. The two ends of the capacitor C7 are respectively connected to the two ends of the secondary winding of the transformer T1. One end of the rectifier diode D3 is connected to the VO- end of the secondary winding of the transformer T1, and the other end is grounded.
5. The switching power supply circuit with wide voltage input according to claim 1, characterized in that: It also includes an input processing module, which includes a resistor R1, a resistor R2, a capacitor C1 and a capacitor C2. The capacitor C1 and the capacitor C2 are connected in series to the VIN end of the switching power supply circuit, and the other end is grounded. The resistor R1 is connected in parallel with the capacitor C1, and the resistor R2 is connected in parallel with the capacitor C2.
6. The switching power supply circuit with wide input voltage according to claim 1, characterized in that: The main control chip U1 is connected to a capacitor C5 and resistors R10 and R11. The capacitor C5 is used to provide a stable operating current for the main control chip U1. The resistors R10 and R11 form a voltage divider network for providing a feedback voltage to the main control chip U1.
7. The switching power supply circuit with wide voltage input according to claim 1, characterized in that: The withstand voltage of the switching power supply circuit is the sum of the withstand voltage of the switch tube Q1 and the withstand voltage of the built-in MOS tube of the main control chip U1.