Power supply circuit and electronic equipment
By using a combination scheme of a trigger circuit and a transformer circuit in the power supply circuit of the power chip, the circuit structure and judgment logic of the dual-branch power supply are simplified, solving the problems of complexity and high power consumption in the existing technology, and achieving a more efficient and Reliable power supply effect.
Patent Information
- Application Number
- CN202323417340.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2023-12-14
- Publication Date
- 2025-01-14
- Estimated Expiration
- 2033-12-14
AI Technical Summary
The existing dual branch power supply scheme requires at least two PWM controllers, resulting in complex circuit structure, high cost, large power consumption and complex judgment logic.
The trigger circuit and the transformer circuit are used as the two power supply branches of the power chip respectively. During the initial power supply, the RC series circuit supplies power. When the capacitor is fully charged, it switches to the transformer circuit for power supply, which simplifies the circuit structure and judgment logic.
The simplified structure and logic of the power supply circuit are realized, the power consumption and cost are reduced, and the stability and reliability of the system are improved.
Smart Images
Figure CN222356183U_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of electricity, and more specifically to a power supply circuit and an electronic device. Background Art
[0002] There are two power supply solutions for power supply chips: a single-branch power supply solution and a dual-branch power supply solution. The dual-branch power supply solution in the related art requires at least two PWM controllers to complete the switching of different power supply branches, and the judgment logic and circuit structure are relatively complex. Utility Model Content
[0003] The utility model is proposed to solve at least one of the above problems. According to the first aspect of the present application, a power supply circuit is provided, the power supply circuit comprising: a power interface, a power chip, a trigger circuit and a transformer circuit; wherein the power interface has a positive pole and a negative pole, and the positive pole and the negative pole of the power interface are used to connect the positive pole and the negative pole of the power supply respectively; the power chip has a power supply end and a reference voltage end; the trigger circuit comprises an RC series circuit, the first end of the RC series circuit is connected to the positive pole of the power interface, and the second end of the RC series circuit is connected to the power supply end; the transformer circuit comprises a primary side and a secondary side, the positive pole of the primary side is connected to the positive pole of the power interface, and the negative pole of the primary side is connected to the ground end; the positive pole of the secondary side is connected to the power supply end, and the negative pole of the secondary side is connected to the ground end.
[0004] In one embodiment of the present application, the trigger circuit further includes: a first RC parallel circuit, wherein two ends of the first RC parallel circuit are respectively connected to the positive electrode and the negative electrode of the power interface.
[0005] In one embodiment of the present application, the trigger circuit further includes: a voltage stabilizing circuit connected between the second end of the RC series circuit and the power supply end.
[0006] In one embodiment of the present application, the voltage stabilizing circuit includes: a transient voltage suppression diode and a first capacitor; wherein the transient voltage suppression diode is connected between the second end of the RC series circuit and the ground terminal; the first capacitor is connected between the second end of the RC series circuit and the ground terminal, and the first capacitor is connected in parallel with the transient voltage suppression diode.
[0007] In one embodiment of the present application, the trigger circuit also includes: a first switch tube; the first end of the first switch tube is connected to the positive pole of the power interface, and the second end of the first switch tube is connected to the power supply end; the control end of the first switch tube is connected to the second end of the RC series circuit; and when the RC series circuit passes current, the first switch tube is turned on.
[0008] In one embodiment of the present application, the trigger circuit also includes: a transistor, the base of the transistor is connected to the second end of the first switch tube, the collector of the transistor is connected to the control end of the first switch tube, and the emitter of the transistor is connected to the second end of the RC series circuit; and when current flows through the RC series circuit, the transistor is configured to be able to control the first switch tube to conduct.
[0009] In one embodiment of the present application, the trigger circuit also includes: a second switch tube, a first end of the second switch tube is connected to the control end of the first switch tube, and a second end of the second switch tube is connected to the ground end; the control end of the second switch tube is connected to the reference voltage end; when the power chip inputs a reference voltage signal through the reference voltage end, the second switch tube is turned on to disconnect the first switch tube.
[0010] In one embodiment of the present application, the trigger circuit also includes: a second RC parallel circuit, a first end of the second RC parallel circuit connecting the reference voltage end and the control end of the second switch tube; a second end of the second RC parallel circuit connecting the ground end and the second end of the second switch tube.
[0011] In one embodiment of the present application, the transformer circuit also includes: a third switch tube, the first end of the third switch tube is connected to the negative pole of the primary side, the second end of the switch tube is connected to the ground end, and the control end of the third switch tube is connected to the power chip; the power chip can control the conduction and disconnection of the third switch tube.
[0012] In one embodiment of the present application, the transformer circuit also includes: a first diode and a second capacitor; wherein the positive electrode of the first diode is connected to the positive electrode of the secondary side; the first end of the second capacitor is connected to the power supply end and the negative electrode of the first diode, and the second end of the second capacitor is connected to the ground end.
[0013] In one embodiment of the present application, the transformer circuit further includes: a second diode, the anode of the second diode is connected to the cathode of the first diode, and the cathode of the second diode is connected to the power supply end and the second end of the RC series circuit.
[0014] In one embodiment of the present application, the power supply circuit further includes: a starting resistor, a first end of the starting resistor is connected to the power supply end, and a second end of the starting resistor is connected to the second end of the RC series circuit and the positive electrode of the secondary side.
[0015] According to a second aspect of the present application, an electronic device is provided, comprising: a power supply, and any one of the power supply circuits described above, wherein the positive and negative poles of the power interface are respectively connected to the positive and negative poles of the power supply.
[0016] According to the power supply circuit and electronic device provided by the embodiment of the present application, a trigger circuit and a transformer circuit are used as two power supply branches of the power chip respectively; at the time of initial power supply, the RC series circuit first supplies power to the power supply end of the power chip; when the capacitor in the RC series circuit is fully charged, the trigger circuit is disconnected from the power chip, the trigger circuit no longer supplies power to the power chip, and switches to the transformer circuit to supply power to the power chip. Compared with the solution of the related art that requires at least two PWM controllers, the judgment logic and circuit structure of the power supply circuit shown in the present application are relatively simple. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.
[0018] Figure 1 A circuit topology diagram of a power supply circuit according to an embodiment of the present utility model;
[0019] Figure 2 A schematic block diagram of two power supply branches shown in an embodiment of the utility model;
[0020] Figure 3 This is a current flow diagram when the trigger circuit is powered according to an embodiment of the present utility model;
[0021] Figure 4 This is a current flow diagram when power is supplied by a transformer circuit according to an embodiment of the present utility model. DETAILED DESCRIPTION
[0022] In order to make the purpose, technical solution and advantages of the utility model more obvious, the exemplary embodiments according to the utility model will be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the utility model, rather than all the embodiments of the utility model, and it should be understood that the utility model is not limited to the exemplary embodiments described here. Based on the embodiments of the utility model described in the utility model, all other embodiments obtained by those skilled in the art without creative work should fall within the protection scope of the utility model.
[0023] In the following description, a large number of specific details are given to provide a more thorough understanding of the utility model. However, it is obvious to those skilled in the art that the utility model can be implemented without one or more of these details. In other examples, in order to avoid confusion with the utility model, some technical features known in the art are not described.
[0024] It should be understood that the utility model can be implemented in different forms and should not be interpreted as being limited to the embodiments proposed herein. On the contrary, providing these embodiments will make the disclosure thorough and complete, and will fully convey the scope of the utility model to those skilled in the art.
[0025] In order to thoroughly understand the present invention, a detailed structure will be presented in the following description to illustrate the technical solution proposed by the present invention. The optional embodiments of the present invention are described in detail below, but in addition to these detailed descriptions, the present invention may also have other implementations.
[0026] In conjunction with the accompanying drawings, some embodiments of the present invention are described in detail below. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.
[0027] In the related art, a single power supply branch is used to supply power to the power chip. In this solution, the power consumption of the power chip is very large under a wide voltage input range, which affects the power efficiency. The embodiment of the present application adopts a dual power supply branch method to solve the defect of high power consumption of the single power supply branch solution, meet the functional safety requirements, and ensure the normal operation of the system.
[0028] The dual power supply branch solution in the related art has the following disadvantages: it requires the use of multiple transformers and flyback power supplies, the circuit structure is relatively complex and the power consumption is relatively large; it requires at least two PWM controllers to judge the switching conditions, resulting in a high circuit cost; there is no voltage stabilization protection circuit in the circuit, and the system reliability needs to be improved; a certain amount of power is required to maintain the operation of the PWM controller, which increases the power consumption, and the switch needs to be turned on and off according to different situations, and the judgment logic is relatively complex. The above technical problems existing in the dual power supply branch solution in the related art can be solved by the technical solutions shown in some embodiments of the present application.
[0029] The present application embodiment provides a power supply circuit, referring to Figure 1The power supply circuit includes: a power interface, a power chip, a trigger circuit and a transformer circuit; wherein the power interface has a positive pole and a negative pole, and the positive pole and the negative pole of the power interface are used to connect the positive pole and the negative pole of the power supply respectively; the power chip has a power supply end and a reference voltage end; the trigger circuit includes an RC series circuit, the first end of the RC series circuit is connected to the positive pole of the power interface, and the second end of the RC series circuit is connected to the power supply end; the transformer circuit includes a primary side and a secondary side, the positive pole of the primary side is connected to the positive pole of the power interface, and the negative pole of the primary side is connected to the ground end; the positive pole of the secondary side is connected to the power supply end, and the negative pole of the secondary side is connected to the ground end.
[0030] In the above scheme, a trigger circuit and a transformer circuit are used as two power supply branches of the power chip respectively; at the time of initial power supply, the RC series circuit first supplies power to the power supply end of the power chip; when the capacitor in the RC series circuit is fully charged, the trigger circuit is disconnected from the power chip, and the trigger circuit no longer supplies power to the power chip, and switches to the transformer circuit to supply power to the power chip. That is, the trigger circuit only works at the initial stage of power-on to supply power to the power chip; when the output of the transformer circuit is stable, it switches to the transformer circuit to supply power to the power chip. Compared with the scheme of the related art that requires at least two PWM controllers, the judgment logic and circuit structure of the power supply circuit shown in this application are relatively simple. The following is a detailed introduction to the above structures in conjunction with the accompanying drawings.
[0031] When setting up the power interface, refer to Figure 1 The power interface has a positive pole and a negative pole, and the positive pole and negative pole of the power interface are used to connect the positive pole and negative pole of the power supply respectively. Specifically, the positive pole of the power interface is connected to the positive pole of the power supply, and the negative pole of the power interface is connected to the negative pole of the power supply. Regarding the structure of the power interface, various types of external connectors such as but not limited to plug-in interfaces, pads, pins, etc. can be used. The power source can be a DC power source that outputs DC power such as but not limited to a battery. When the DC power source supplies power through the power interface, the power supply mode can be a trigger type, a forward type, or a flyback type.
[0032] When setting the power chip, refer to Figure 1 The power chip has a power supply terminal and a reference voltage terminal. The power chip can convert the direct current input from the power supply terminal into one or more reference voltages and output them through the reference voltage terminal. Exemplarily, the power supply terminal can be a pin on the power chip, and the reference voltage terminal can be another pin on the power chip. Exemplarily, the module constituting the power chip includes, in addition to the power chip, a power chip auxiliary circuit. The power chip auxiliary circuit ensures that each pin of the power chip works normally and provides reliability and stability for the system and the module.
[0033] When setting up the trigger circuit, refer to Figure 1The trigger circuit is used as the first power supply branch, and has an RC series circuit. The RC series circuit has two ends. The first end of the RC series circuit is connected to the positive electrode of the power interface, and the second end of the RC series circuit is connected to the power supply end. The RC series circuit can be any RC circuit formed by connecting a resistor and a capacitor in series. For example, refer to Figure 1 The RC series circuit includes a resistor R2 and a capacitor C2, and the resistor R2 and the capacitor C2 are connected in series. The resistor R2 is connected between the positive electrode of the power interface and the capacitor C2, and the capacitor C2 is connected between the resistor R2 and the power supply end of the power chip. When the power supply is initially powered, the RC series circuit serves as the first power supply branch and can first power the power supply end of the power chip.
[0034] When setting up the transformer circuit, Figure 1 As shown, the transformer circuit includes a primary side and a secondary side, wherein the primary side serves as an input auxiliary winding of the transformer, the positive pole of the primary side is connected to the positive pole of the power interface, and the negative pole of the primary side is connected to the ground terminal. The ground terminal can provide a stable zero potential. The secondary side serves as an output auxiliary winding of the transformer, the positive pole of the secondary side is connected to the power supply terminal, and the negative pole of the secondary side is connected to the ground terminal. Therefore, when the power supply adopts a trigger type, a forward type, a flyback type, etc., when the conditions are met, the transformer circuit can be used as a second power supply branch to power the power chip. In some embodiments, when the trigger circuit only includes an RC series circuit, when the capacitor in the RC series circuit is fully charged, the trigger circuit is disconnected from the power chip, and the trigger circuit no longer supplies power to the power chip, and switches to the transformer circuit to supply power to the power chip.
[0035] Exemplary, reference Figure 1 The trigger circuit may further include: a first RC parallel circuit, wherein two ends of the first RC parallel circuit are respectively connected to the positive electrode and the negative electrode of the power interface. Figure 1 , the first end of the first RC parallel circuit is connected to the positive electrode of the power interface, and the second end of the first RC parallel circuit is connected to the negative electrode of the power interface. Therefore, when the power supply is connected to the power interface, the first RC parallel circuit can provide functions such as but not limited to delay, filtering, and rectification. When setting the first RC parallel circuit, any RC parallel circuit formed by a resistor and a capacitor in parallel can be used. For example, refer to Figure 1 The first RC parallel circuit includes a resistor R1 and a capacitor C1 connected in parallel, wherein the two ends of the resistor R1 are respectively connected to the positive and negative electrodes of the power interface, and the two ends of the capacitor C1 are respectively connected to the positive and negative electrodes of the power interface, so as to perform, for example but not limited to, delay, filter, and rectify the current just input from the power interface.
[0036] Exemplary, reference Figure 1The trigger circuit may also include: a voltage stabilizing circuit, which is connected between the second end of the RC series circuit and the power supply end, so that when the first power supply branch supplies power to the power supply end of the power chip, it can provide a voltage stabilizing function. When setting the voltage stabilizing circuit, multiple methods can be used.
[0037] Exemplary, reference Figure 1 , the voltage stabilizing circuit may include: a transient voltage suppression diode and a first capacitor. Figure 1 and Figure 3 The TVS in the above code indicates transient voltage suppression diode. Figure 1 and Figure 3 C3 in the figure represents a first capacitor. The transient voltage suppression diode is connected between the second end of the RC series circuit and the ground. The first capacitor is connected between the second end of the RC series circuit and the ground, and the first capacitor is connected in parallel with the transient voltage suppression diode. Of course, the arrangement of the voltage stabilizing circuit is not limited to the above-mentioned arrangement. For example, a voltage stabilizing chip can also be used as the voltage stabilizing circuit.
[0038] In the above embodiments, reference Figure 1 and Figure 2 The trigger circuit includes a voltage regulator circuit. The trigger circuit only works at the initial power-on stage to supply power to the power chip. The voltage regulator circuit is connected to the power chip. The voltage regulator circuit stabilizes and filters the output voltage of the trigger circuit to meet the power supply requirements of the power chip. The power chip is connected to the transformer circuit. After the transformer circuit works stably, it supplies power to the power chip to ensure the normal operation of the power chip, while reducing power consumption and increasing the stability and reliability of the system. Figure 3 and Figure 4 , the current path is supplied to the power chip through the RC series circuit, the TVS tube and the first capacitor C3, and then the voltage is stabilized. After switching to the transformer circuit for power supply, the TVS tube and the first capacitor C3 stop working. That is, when the transformer circuit supplies power, the voltage stabilization circuit stops working.
[0039] Exemplary, reference Figure 1 The trigger circuit may further include: a first switch tube, such as Figure 1Q1 in the figure represents the first switch tube. The first end of the first switch tube is connected to the positive pole of the power interface, and the second end of the first switch tube is connected to the power supply end; the control end of the first switch tube is connected to the second end of the RC series circuit; and when the RC series circuit is conducting current, the first switch tube is turned on. That is, in the process of the power supply conducting current through the RC series circuit, the current output by the second end of the RC series circuit can control the first switch tube to conduct, so that the positive pole of the power interface can also be electrically connected to the power supply end of the power chip through the first switch tube, and the power supply end of the power chip is powered. In this process, the function of the RC series circuit is not limited to serving as the first power supply branch to supply power to the power chip, but can also provide functions such as but not limited to filtering, rectification, delay, etc.
[0040] When setting the first switch tube, various methods can be used. For example, the first switch tube can include but is not limited to MOSFET, IGBT, silicon carbide and other switching devices. For example, refer to Figure 1 The first switch tube is selected to use an N-type MOS tube. After the second end of the RC series circuit powers on the control end of the first switch tube, the first switch tube can be controlled to be turned on. Of course, in other embodiments, other methods can be used. For example, a triode can also be used as the first switch tube.
[0041] Exemplary, reference Figure 1 and Figure 3 , the trigger circuit may also include: a transistor, such as Figure 1 and Figure 3 Q2 in the figure represents a transistor. Figure 1 and Figure 3 , the base of the transistor is connected to the second end of the first switch tube, the collector of the transistor is connected to the control end of the first switch tube, and the emitter of the transistor is connected to the second end of the RC series circuit. When the RC series circuit is flowing with current, the transistor is configured to control the first switch tube to be turned on. That is, when the RC series circuit is flowing with current, the transistor can clamp the control end of the first switch tube, thereby controlling the first switch tube to be turned on. When setting the transistor, refer to Figure 1 and Figure 3 , you can choose to use NPN transistor.
[0042] Exemplary, reference Figure 1 and Figure 3 , the trigger circuit may also include: a current limiting resistor, such as Figure 1 and Figure 3 R4 in the figure represents a current limiting resistor. A first end of the current limiting resistor is connected to a second end of the first switch tube, and a second end of the current limiting resistor is connected to a power supply end of the power chip, so that when the power chip is powered by the first switch tube, the current limiting resistor can limit the current.
[0043] In some embodiments, reference Figure 1 and Figure 3 The trigger circuit may further include: a second switch tube, such as Figure 1 and Figure 3 Q3 in the figure represents the second switch tube. The first end of the second switch tube is connected to the control end of the first switch tube, and the second end of the second switch tube is connected to the ground end; the control end of the second switch tube is connected to the reference voltage end. When the power chip inputs a reference voltage signal through the reference voltage end, the second switch tube is turned on to disconnect the first switch tube. After the power chip is able to supply power through the transformer circuit, the power chip can output a reference voltage signal to the second switch tube to turn on the second switch tube, thereby connecting the control end of the first switch tube to the ground end, thereby controlling the first switch tube to disconnect, so that the trigger circuit no longer supplies power to the power chip. When setting the second switch tube, a variety of methods can be used. Exemplarily, the second switch tube may include but is not limited to switching devices such as MOSFET, IGBT, and silicon carbide. Exemplarily, refer to Figure 1 and Figure 3 , the second switch tube can be selected as an N-type MOS tube. Of course, in other embodiments, a triode can also be used as the second switch tube. For example, Figure 1 and Figure 3 BVREF5V in the figure represents a reference voltage signal of 5 V. Of course, the reference voltage signal is not limited to 5 V, and can also be a reference voltage signal of other voltage values.
[0044] Exemplary, reference Figure 1 and Figure 3 , the trigger circuit may also include: a second RC parallel circuit, the first end of the second RC parallel circuit is connected to the reference voltage end and the control end of the second switch tube; the second end of the second RC parallel circuit is connected to the ground end and the second end of the second switch tube. Therefore, when the reference voltage end of the power chip outputs a reference voltage signal to the control end of the second switch tube, the reference voltage signal can be filtered to improve the reliability and stability of controlling the conduction of the second switch tube. When setting the second RC parallel circuit, a variety of methods can be used. For example, reference Figure 1 and Figure 3 The second RC parallel resistor includes a resistor R4 and a capacitor C4 connected in parallel. The first end formed by the resistor R4 and the capacitor C4 connected in parallel serves as the first end of the second RC parallel circuit, and is connected to the reference voltage end and the control end of the second switch tube. The second end formed by the resistor R4 and the capacitor C4 connected in parallel serves as the second end of the second RC parallel circuit, and is connected to the ground end and the second end of the second switch tube.
[0045] Exemplary, reference Figure 1 and Figure 3 The transformer circuit may further include: a third switch tube, such as Figure 1 and Figure 3 Q4 in the figure represents the third switch tube. The first end of the third switch tube is connected to the negative pole of the primary side, the second end of the switch tube is connected to the ground terminal, and the control end of the third switch tube is connected to the power chip. The power chip can control the third switch tube to be turned on and off. After the power supply supplies power to the power chip through the trigger circuit, the power chip can control the third switch tube to be turned on so that the transformer circuit starts working. And after the current input to the transformer circuit meets the requirements, the power supply can be switched from the trigger circuit to the transformer circuit. The specific switching method can be as described above by controlling the second switch tube to be turned on to disconnect the first switch tube. When setting the third switch tube, a variety of methods can be used. Exemplarily, the third switch tube may include but is not limited to switching devices such as MOSFET, IGBT, and silicon carbide.
[0046] Exemplary, reference Figure 1 and Figure 3 The third switch tube can be an N-type MOS tube, and the control end of the third switch tube can also be connected to the reference voltage end of the power chip, so that the power chip can control the third switch tube to be turned on by outputting a reference voltage signal to the control end of the third switch tube. Of course, in other embodiments, the third switch tube can also be in other ways. For example, a triode can also be used as the switch tube.
[0047] Exemplary, reference Figure 1 and Figure 4 , the transformer circuit may further include: a first diode and a second capacitor. Figure 1 and Figure 4 D1 in the figure represents the first diode. Figure 1 and Figure 4 C5 in the figure represents a second capacitor. The positive electrode of the first diode is connected to the positive electrode of the secondary side; the first end of the second capacitor is connected to the power supply end and the negative electrode of the first diode, and the second end of the second capacitor is connected to the ground end. Through the first diode and the second capacitor, the current signal output from the positive electrode of the secondary side can be rectified, filtered, etc. but not limited to. The first diode can be a rectifier diode and other rectifier devices that use diodes to achieve rectification.
[0048] Exemplary, reference Figure 1 and Figure 4 , the transformer circuit may further include: a second diode, such as Figure 1 and Figure 4 D2 in the figure represents a second diode. The anode of the second diode is connected to the cathode of the first diode, and the cathode of the second diode is connected to the power supply end and the second end of the RC series circuit. By setting the second diode, it is possible to prevent the trigger circuit from backflowing current to the anode of the secondary side during the process of supplying power to the power chip, thereby affecting the normal operation of the transformer circuit.
[0049] Exemplary, reference Figure 1 , the power supply circuit may also include: a starting resistor, such as Figure 1 , Figure 3 and Figure 4 R3 in the figure represents a startup resistor. The first end of the startup resistor is connected to the power supply end, and the second end of the startup resistor is connected to the second end of the RC series circuit and the positive electrode of the secondary side, so that the first power supply branch is connected to the power supply end of the power chip through the startup resistor to perform functions such as but not limited to current limiting. For example, refer to Figure 1 The starting resistor is also connected between the positive electrode of the secondary side and the power supply end of the power chip, that is, the second power supply branch is also connected to the power supply end of the power chip through the starting resistor.
[0050] Exemplary, reference Figure 1 , the transformer circuit may also include: auxiliary resistors, such as Figure 1 R6 in the figure represents an auxiliary resistor. One end of the auxiliary resistor is connected to the positive electrode of the primary side, and the other end of the auxiliary resistor is connected to the negative electrode of the second diode. Regarding the setting of the auxiliary resistor, auxiliary components and auxiliary circuits may be used, such as but not limited to, and auxiliary circuits or auxiliary components may be added according to design requirements.
[0051] For example, the following is combined Figure 1 , Figure 3 and Figure 4 The accompanying drawings are shown to exemplarily describe several application modes.
[0052] Exemplary, reference Figure 1 and Figure 3 The trigger circuit is composed of the first RC parallel circuit (resistor R1 and capacitor C1), RC series circuit (resistor R2 and capacitor C2), starting resistor R3, and voltage stabilizing circuit (TVS tube and capacitor C3). Among them, resistor R1 and capacitor C1 are connected in parallel, and are connected in series with resistor R2 and capacitor C2 in sequence. The starting resistor R3 is connected in series with the RC series circuit. The voltage stabilizing circuit is connected to the RC series circuit. The TVS tube is connected to the ground terminal, and the current loop is as follows Figure 3 In the initial stage of power-on, the transformer circuit (TR1) has no output yet, and the power chip needs to be powered by the startup resistor (R3).
[0053] refer to Figure 1 and Figure 3, the trigger circuit includes but is not limited to an RC series circuit and a switch tube switching circuit. The switch tube switching circuit includes a first switch tube (Q1), a triode (Q2), a second switch tube (Q3) and a peripheral auxiliary circuit. The first switch tube (Q1), the second switch tube (Q3) and the triode (Q2) are connected in parallel in sequence, and the control end of the second switch tube is connected to the reference voltage end of the power chip. When the power supply is supplied, the triode clamps the first switch tube so that the first switch tube works in the amplification area, and the trigger circuit supplies power to the power chip. When the reference voltage end of the power chip stably outputs a reference voltage signal, it is fed back to the first switch tube (Q1), the first switch tube is disconnected, and the trigger circuit no longer supplies power to the power chip, that is, it switches to the transformer circuit for power supply.
[0054] Exemplary, reference Figure 1 and Figure 3 , the trigger circuit includes an RC series circuit, an RC parallel circuit, and a switch tube switching circuit. When the trigger circuit only includes the RC series circuit (excluding the switch tube switching circuit), the current path passes through the RC series circuit from the power supply. When the capacitor C2 in the RC series circuit is fully charged, the trigger circuit is disconnected from the power chip, that is, the trigger circuit no longer supplies power to the power chip, and switches to the transformer circuit to supply power to the power chip. When the trigger circuit includes both the RC series circuit and the switch tube switching circuit, the RC series circuit plays a delay and filtering role. The current path passes through the RC series circuit to the first switch tube. The first switch tube is turned on, and the trigger circuit supplies power to the power chip. After the delay, the transformer circuit outputs stably, and the power chip enable pin outputs 5V to the control end of the second switch tube, so that the first switch tube is disconnected, and the transformer circuit continues to supply power to the power chip.
[0055] The specific power supply process is as follows: At the initial stage of system power-on, the current path flows from the trigger circuit to the voltage stabilizing circuit, and then flows through the power chip. The trigger circuit supplies power to the power chip, and the parameters of each device in the trigger circuit are set according to the power supply requirements of the power chip. After the power chip works, the third switch tube (Q4) is controlled to be turned on, and the transformer circuit starts to work. After the transformer circuit outputs stably, it supplies power to the power chip. After the set time delay, the power chip output is fed back to the trigger circuit, and the trigger circuit is disconnected from the power chip. At the same time, the transformer circuit is connected to the power supply end of the power chip, and the transformer circuit relays the power supply to the power chip.
[0056] refer to Figure 1 and Figure 4The transformer circuit is composed of a primary side, a secondary side, a first diode (D1), a second capacitor (C5), and a second diode (D2). The primary side, the secondary side, the first diode, and the second diode are connected in series in sequence. The second capacitor is connected in parallel between the first diode and the second diode, and the second capacitor is connected to the ground terminal. The primary and secondary sides of the transformer circuit, the first diode, the second capacitor, and the second diode are connected in series in sequence, and the cathode of the second diode is connected to the power supply terminal of the power chip. The current loop is as follows Figure 4 As shown by the dotted line, the secondary side → the first diode → the second capacitor → the second diode. In addition, the transformer circuit may also include but is not limited to an auxiliary resistor (R6) connected in series with the power chip. For example, refer to Figure 1 and Figure 4 The transformer circuit further includes a third switch tube (Q4). After the third switch tube (Q4) is turned on, the first diode and the second capacitor rectify and filter the output voltage of the secondary side of the transformer to ensure the working stability of the power chip.
[0057] like Figure 3 The current flow direction shown is when the power is turned on. The current flows through the resistor R1, the capacitor C1, the resistor R2, the capacitor C2 to the voltage regulator circuit, and then flows to the power supply end of the power chip through the voltage regulator circuit. Assuming the input voltage is U in , the input current is i, the voltage at point A is U A (t), then:
[0058] i·R 1 +U A (t) = U in (1)
[0059] again
[0060]
[0061] The relationship between the voltage and time at point A can be expressed as:
[0062]
[0063] Where C is a constant.
[0064] The relationship between the voltage and time at point B can be expressed as:
[0065]
[0066] Combining equations (3) and (4), we can get the expression of the RC circuit delay time t:
[0067]
[0068] The solution is:
[0069]
[0070] Where C is a constant.
[0071] According to the above formulas, it can be seen that the delay time t is related to the input voltage, resistance R1, capacitance C1, resistance R2, and capacitance C2. The parameters of resistance R1, capacitance C1, resistance R2, and capacitance C2 can be set to meet the design requirements. The power supply chip can be flexibly designed while ensuring stable power supply. It is suitable for chip power supply in different application scenarios.
[0072] like Figure 4 As shown in the figure, the power supply current flow direction of the transformer circuit, the current flows from the primary side and the secondary side of the transformer, and then flows through the first diode, the second capacitor, the second diode to the power supply pin of the power chip. Assuming that the time for the transformer circuit to supply power to the power chip is t', the power consumption saved can be expressed as:
[0073]
[0074] It can be seen from formula (7) that the power consumption is related to the auxiliary resistor R6 of the circuit and the power supply time. If the system is powered on continuously for a long time, the power consumption can be reduced to a certain extent.
[0075] In the various embodiments shown above, the trigger circuit and the transformer circuit are used as two power supply branches of the power chip respectively; at the time of initial power supply, the RC series circuit first supplies power to the power supply end of the power chip; when the capacitor in the RC series circuit is fully charged, the trigger circuit is disconnected from the power chip, the trigger circuit no longer supplies power to the power chip, and the transformer circuit is switched to supply power to the power chip. Compared with the solution of the related art that requires at least two PWM controllers, the judgment logic and circuit structure of the power supply circuit shown in this application are relatively simple.
[0076] Compared with the related art, the scheme in some embodiments of the present application has the following beneficial effects. In the actual application of the circuit, the components and traces on the circuit board have certain reactance (impedance, capacitive reactance, inductive reactance), and the voltage difference generated by the parasitic inductance is U=L di / dt. When the current change rate is large enough, a relatively large peak voltage will be generated in the loop. This peak voltage also contains a large peak energy. In some embodiments of the present application, the characteristic that the voltage across the capacitor cannot change suddenly is used. The use of RC series circuits and RC parallel circuits can reduce the peak and absorb energy to improve the stability of the power supply for the chip. In some embodiments of the utility model, a power supply method combining a trigger circuit and a transformer circuit is adopted to reduce the power loss of the power supply. The trigger circuit can be flexibly designed. The switching circuit composed of the RC series circuit, the RC parallel circuit and the switch tube in the trigger circuit can be used in the circuit at the same time. The RC series circuit and the RC parallel circuit delay the power supply, and the redundant design can improve the reliability of the circuit design. While ensuring normal power supply, there is no need to perform logical judgment, which simplifies the judgment steps and can be applied to different scenarios. If applied to a flyback circuit, the trigger circuit supplies power to the power chip through the battery terminal at the initial stage of power-on. After switching to the transformer circuit for power supply, the current loop no longer flows through the resistor and other components in the trigger circuit, which greatly reduces power consumption and further improves the efficiency of the flyback power supply. According to the startup time of different transformer circuits, the corresponding parameters of different devices in the trigger circuit are designed to ensure a stable startup circuit, and a certain margin is left to improve the reliability of the product. In addition, the power supply circuit provided in the embodiment of the present application only uses one flyback power supply, designs the circuit switching time through an RC series circuit and an RC parallel circuit, uses simple components to design the circuit, and does not require complex logical judgment, which greatly reduces the complexity of the circuit. In some embodiments, the present application also introduces a voltage stabilizing circuit, which can keep the output DC voltage stable when the power supply voltage or load changes, and prevent the power chip from overvoltage at the moment of power startup. In some embodiments, the present application also adds a second diode as an anti-reverse diode to prevent current backflow from damaging components. The circuit is simple and low-cost, and the system stability is further improved.
[0077] In addition, an embodiment of the present application provides an electronic device, which includes: a power supply, and any one of the above-mentioned power supply circuits, wherein the positive and negative electrodes of the power interface are respectively connected to the positive and negative electrodes of the power supply. The electronic device may be various types of electronic devices such as, but not limited to, vehicle-mounted terminals, mobile terminals, wearable devices, computers, vehicle-mounted controllers, etc. The power supply may be, but not limited to, a power battery, an energy storage battery, etc., and the type of the power supply may be, but not limited to, a flyback power supply, a forward power supply, a trigger power supply, etc.
[0078] The utility model has been described through the above embodiments, but it should be understood that the above embodiments are only for the purpose of example and description, and are not intended to limit the utility model to the scope of the described embodiments. In addition, it can be understood by those skilled in the art that the utility model is not limited to the above embodiments, and more variations and modifications can be made according to the teachings of the utility model, and these variations and modifications all fall within the scope of protection claimed by the utility model. The protection scope of the utility model is defined by the attached claims and their equivalents.
Claims
1. A power supply circuit, characterized in that: include: A power interface, having a positive pole and a negative pole; the positive pole and the negative pole of the power interface are used to connect the positive pole and the negative pole of the power supply respectively; A power chip having a power supply terminal and a reference voltage terminal; The trigger circuit comprises an RC series circuit; a first end of the RC series circuit is connected to the positive electrode of the power interface, and a second end of the RC series circuit is connected to the power supply end; A transformer circuit comprises a primary side and a secondary side; wherein the positive pole of the primary side is connected to the positive pole of the power interface, and the negative pole of the primary side is connected to the ground terminal; the positive pole of the secondary side is connected to the power supply terminal, and the negative pole of the secondary side is connected to the ground terminal.
2. The power supply circuit according to claim 1, characterized in that: The trigger circuit also includes: A first RC parallel circuit, wherein two ends of the first RC parallel circuit are respectively connected to the positive electrode and the negative electrode of the power interface.
3. The power supply circuit according to claim 1, characterized in that: The trigger circuit further includes: a voltage stabilizing circuit connected between the second end of the RC series circuit and the power supply end.
4. The power supply circuit according to claim 3, characterized in that: The voltage stabilizing circuit comprises: a transient voltage suppression diode connected between the second end of the RC series circuit and the ground terminal; The first capacitor is connected between the second end of the RC series circuit and the ground end, and is connected in parallel with the transient voltage suppression diode.
5. The power supply circuit according to claim 1, characterized in that: The trigger circuit also includes: A first switch tube; the first end of the first switch tube is connected to the positive electrode of the power interface, and the second end of the first switch tube is connected to the power supply end; the control end of the first switch tube is connected to the second end of the RC series circuit; and when current flows through the RC series circuit, the first switch tube is turned on.
6. The power supply circuit according to claim 5, characterized in that: The trigger circuit further includes: a triode, wherein the base of the triode is connected to the second end of the first switch tube, the collector of the triode is connected to the control end of the first switch tube, and the emitter of the triode is connected to the second end of the RC series circuit; When current flows through the RC series circuit, the transistor is configured to control the first switch tube to conduct.
7. The power supply circuit according to claim 5, characterized in that: The trigger circuit also includes: a second switch tube, wherein a first end of the second switch tube is connected to a control end of the first switch tube, a second end of the second switch tube is connected to the ground end, and a control end of the second switch tube is connected to the reference voltage end; When the power chip inputs a reference voltage signal through the reference voltage terminal, the second switch tube is turned on to turn off the first switch tube.
8. The power supply circuit according to claim 7, characterized in that: The trigger circuit also includes: A second RC parallel circuit, wherein a first end of the second RC parallel circuit is connected to the reference voltage end and the control end of the second switch tube; and a second end of the second RC parallel circuit is connected to the ground end and the second end of the second switch tube.
9. The power supply circuit according to claim 1, characterized in that: The transformer circuit further includes: A third switch tube, wherein the first end of the third switch tube is connected to the negative electrode of the primary side, the second end of the switch tube is connected to the ground end, and the control end of the third switch tube is connected to the power chip; the power chip can control the conduction and disconnection of the third switch tube.
10. The power supply circuit according to claim 1, characterized in that: The transformer circuit further includes: a first diode, wherein an anode of the first diode is connected to an anode of the secondary side; A second capacitor, wherein a first end of the second capacitor is connected to the power supply end and the cathode of the first diode, and a second end of the second capacitor is connected to the ground end.
11. The power supply circuit according to claim 10, characterized in that: The transformer circuit further includes: A second diode, wherein the anode of the second diode is connected to the cathode of the first diode, and the cathode of the second diode is connected to the power supply end and the second end of the RC series circuit.
12. The power supply circuit according to claim 1, characterized in that: Also includes: A starting resistor, wherein a first end of the starting resistor is connected to the power supply end, and a second end of the starting resistor is connected to the second end of the RC series circuit and the positive electrode of the secondary side.
13. An electronic device, characterized in that: include: A power supply, and a power supply circuit according to any one of claims 1 to 12, wherein the positive electrode and the negative electrode of the power interface are connected to the positive electrode and the negative electrode of the power supply respectively.