Integrated synchronous rectification controller, flyback converter and electronic equipment

Abstract

The invention provides an integrated synchronous rectification controller, a flyback converter and electronic equipment, the integrated synchronous rectification controller comprises a first switch tube and a synchronous rectification controller, the synchronous rectification controller comprises a sampling circuit, a transistor, a power supply circuit, a detection circuit and a logic control circuit; the first switch tube, the sampling circuit and the transistor are arranged on the first bare chip; the power supply circuit, the detection circuit and the logic control circuit are arranged on the second bare chip; the first bare chip is manufactured by adopting a high-voltage process, and the second bare chip is manufactured by adopting a low-voltage process; the synchronous rectification controller is used for controlling on or off of the first switch tube. The high-voltage circuit part in the synchronous rectification controller is arranged on the first bare chip, and the low-voltage circuit part is arranged on the second bare chip, so that the high-voltage circuit part and the low-voltage circuit part are separated, and the second bare chip only needs to be manufactured by a low-voltage process. The manufacturing cost of the synchronous rectification controller can be reduced, and then the dependency degree on the technological process is reduced.

Description

Technical Field

[0001] The present application relates to the technical field of power management chips, and in particular to an integrated synchronous rectification controller, a flyback converter and an electronic device. Background Art

[0002] With the continuous development of the global economy, energy shortage is becoming increasingly serious. Energy conservation, emission reduction and green economy have become the general consensus of major countries and regions in the world. In recent years, in order to further improve global energy conservation, global regulatory agencies have proposed new efficiency standards. In the power supply industry, in addition to safety performance, it is more urgent to improve the conversion efficiency of power supplies and reduce no-load standby power consumption. The U.S. Department of Energy (Department of A series of new requirements issued by the Department of Energy (DOE) require manufacturers to improve the efficiency of existing independent power supply products, and they can enter the US market for sale only after the efficiency reaches the 6th level of energy efficiency (DOE VI) standard. In addition, manufacturers also need to design products that meet other energy specifications, such as the EU CoC V5Tier2 standard, to further regulate and improve the energy efficiency requirements of independent power supply products.

[0003] To improve the efficiency of the power adapter in converting AC to DC, see Figure 1 , Figure 1 A flyback converter is provided in the related art. Figure 1 Replacing the freewheeling Schottky diode (i.e., P1) in the flyback converter with a synchronous rectifier controller (SR) based on a metal-oxide-semiconductor field-effect transistor (MOSFET) can improve efficiency by 2% to 3% or more. In addition, the use of a synchronous rectifier controller also helps save the cost of the freewheeling Schottky diode heat sink and the cost of manual assembly. Designers can also save further costs by choosing a cheaper MOSFET while still achieving the target efficiency. Summary of the invention

[0004] The present application provides an integrated synchronous rectification controller, a flyback converter and an electronic device to reduce the manufacturing cost of the synchronous rectification controller. The specific technical solution is as follows:

[0005] In a first aspect, the present application provides an integrated synchronous rectification controller, the integrated synchronous rectification controller comprising: a first switch tube and a synchronous rectification controller, wherein a control end of the first switch tube is electrically connected to the synchronous rectification controller;

[0006] The synchronous rectification controller includes: a sampling circuit, a transistor, a power supply circuit, a detection circuit and a logic control circuit; the first switch tube, the sampling circuit and the transistor are arranged on a first bare chip; the power supply circuit, the detection circuit and the logic control circuit are arranged on a second bare chip; wherein the first bare chip is manufactured by a high-voltage process, and the second bare chip is manufactured by a low-voltage process;

[0007] The synchronous rectification controller is used to control the on or off of the first switch tube.

[0008] In a possible design, the input end of the transistor is electrically connected to the feedback voltage end, and the output end of the transistor is electrically connected to the input end of the sampling circuit and the input end of the power supply circuit respectively; the output end of the sampling circuit is electrically connected to the first input end of the detection circuit; the output end of the power supply circuit is electrically connected to the second input end of the detection circuit and the first input end of the logic control circuit respectively; the output end of the detection circuit is electrically connected to the second input end of the logic control circuit; the output end of the logic control circuit is electrically connected to the control end of the first switch tube;

[0009] The transistor is used to clamp the feedback voltage connected to the feedback voltage terminal, output the clamped voltage, and transmit the clamped voltage to the sampling circuit and the power supply circuit respectively;

[0010] The power supply circuit is used to receive the clamping voltage, charge itself, and provide power for the detection circuit and the logic control circuit;

[0011] The sampling circuit is used to collect the clamping voltage, output a voltage signal, and transmit the voltage signal to the detection circuit;

[0012] The detection circuit is used to process the voltage signal, output a control signal, and transmit the control signal to the logic control circuit;

[0013] The logic control circuit is used to control the on or off of the first switch tube according to the control signal.

[0014] In one possible design, the sampling circuit includes: a first resistor and a second resistor;

[0015] The first end of the first resistor is electrically connected to the output end of the transistor, and the second end of the first resistor is electrically connected to the first end of the second resistor and the input end of the detection circuit respectively;

[0016] A second terminal of the second resistor is grounded.

[0017] In one possible design, the transistor is a junction field effect transistor.

[0018] In a possible design, the first switch tube is a MOSFET tube.

[0019] In a second aspect, the present application provides a flyback converter, the flyback converter comprising: the integrated synchronous rectification controller as described in the first aspect, further comprising a switching circuit, a voltage conversion circuit and an output filter circuit; the voltage conversion circuit comprises a primary winding and a secondary winding;

[0020] The input end of the switch circuit is used to access input energy, the first output end of the switch circuit is electrically connected to the first input end of the transformer circuit, and the second output end of the switch circuit is electrically connected to the second input end of the transformer circuit; the first output end of the transformer circuit is electrically connected to the input end of the output filter circuit and the output end of the output filter circuit respectively, and the second output end of the transformer circuit is electrically connected to the input end of the integrated synchronous rectification controller; the output end of the integrated synchronous rectification controller is grounded;

[0021] When the switch circuit is turned on, the voltage conversion circuit is used to store the received input energy in the primary winding to obtain stored energy;

[0022] When the switch circuit is turned off, the voltage conversion circuit is used to transfer the stored energy to the secondary winding, so that the stored energy is rectified and filtered by the integrated synchronous rectification controller and the output filter circuit and converted into an output voltage.

[0023] In a possible design, the switch circuit includes: a first capacitor, a third resistor, a diode and a second switch tube;

[0024] The first end of the first capacitor is electrically connected to the first end of the third resistor, the input end of the switch circuit, and the first output end of the switch circuit respectively; the input end of the switch circuit is used to access the input energy;

[0025] The second end of the first capacitor is electrically connected to the second end of the third resistor and the first end of the diode respectively;

[0026] The second end of the diode is electrically connected to the first end of the second switch tube and the second output end of the switch circuit respectively;

[0027] The second end of the second switch tube is grounded, and the control end of the second switch tube is used to access the PWM signal.

[0028] In one possible design, the voltage transformation circuit includes: a transformer;

[0029] A first tap of the primary winding of the transformer is electrically connected to a first output terminal of the switch circuit, and a second tap of the primary winding of the transformer is electrically connected to a second output terminal of the switch circuit;

[0030] A first tap of the secondary winding of the transformer is electrically connected to an input end of the output filter circuit, and a second tap of the secondary winding of the transformer is electrically connected to an input end of the synchronous rectification controller.

[0031] In one possible design, the output filter circuit includes: a second capacitor;

[0032] A first end of the second capacitor is electrically connected to an input end of the output filter circuit and an output end of the output filter circuit respectively, and a second end of the second capacitor is grounded.

[0033] In a third aspect, the present application provides an electronic device, which includes the flyback converter in the second aspect.

[0034] Beneficial effects of the embodiments of the present application:

[0035] In an embodiment of the present application, an integrated synchronous rectification controller includes: a first switch tube and a synchronous rectification controller, wherein the control end of the first switch tube is electrically connected to the synchronous rectification controller; the synchronous rectification controller includes: a sampling circuit, a transistor, a power supply circuit, a detection circuit and a logic control circuit; the first switch tube, the sampling circuit and the transistor are arranged on a first die; the power supply circuit, the detection circuit and the logic control circuit are arranged on a second die; wherein the first die is manufactured by a high-voltage process and the second die is manufactured by a low-voltage process; the high-voltage circuit part in the synchronous rectification controller is arranged on the first die that needs to adopt a high-voltage process, and the low-voltage circuit part in the synchronous rectification controller is arranged on the second die, so as to realize the separation of the high-voltage circuit part and the low-voltage circuit part in the synchronous rectification controller, so that the second die only needs to be manufactured by a low-voltage process. Compared with the synchronous rectification controller including the high-voltage circuit part and the low-voltage circuit part, which needs to be manufactured by both the high-voltage process and the low-voltage process, the synchronous rectification controller in the integrated synchronous rectification controller provided by the present application only needs to adopt the low-voltage process, which can reduce the manufacturing cost of the synchronous rectification controller and further reduce the dependence on the process.

[0036] The beneficial effects provided in the above-mentioned second aspect and various possible designs of the above-mentioned second aspect can refer to the beneficial effects brought about by the above-mentioned first aspect and various possible implementation methods of the first aspect, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application, and for ordinary technicians in this field, other embodiments can also be obtained based on these drawings.

[0038] Figure 1 A schematic diagram of the structure of a flyback converter provided for related technology;

[0039] Figure 2 A schematic diagram of the structure of a flyback converter with a synchronous rectification controller provided in the related art;

[0040] Figure 3 A schematic diagram of the structure of a flyback converter with a synchronous rectification controller integrating a MOSFET tube provided in the related art;

[0041] Figure 4 A schematic diagram of the structure of an integrated synchronous rectification controller provided in one embodiment of the present application;

[0042] Figure 5 A schematic diagram of the structure of a flyback converter provided in one embodiment of the present application;

[0043] Figure 6 A schematic diagram of the circuit structure of a sampling circuit provided in one embodiment of the present application. DETAILED DESCRIPTION

[0044] In this application, "at least one" means one or more, and "plurality" means two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone, where A and B can be singular or plural. The character " / " generally indicates that the associated objects before and after are in an "or" relationship. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b, or c alone can represent: a, b, c, a and b, a and c, or a, b, and c, where a, b, and c can be single or multiple. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0045] The directions or positional relationships indicated by terms such as "center", "longitudinal", "lateral", "up", "down", "left", "right", "front", and "back" are based on the directions or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present application and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present application.

[0046] The terms "connected" and "connected" should be understood in a broad sense. For example, the "connected" or "connected" of a circuit structure can refer to not only physical connection, but also electrical connection or signal connection. For example, it can be directly connected, that is, physically connected, or indirectly connected through at least one intermediate element, as long as the circuit is connected, or it can be the internal connection of two elements; signal connection can refer to signal connection through a circuit or through a media medium, such as radio waves. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0047] In the related art, the freewheeling Schottky diode in the flyback converter is replaced with a synchronous rectifier controller (SR) based on a metal-oxide-semiconductor field-effect transistor (MOSFET). Since the on-state voltage drop of the freewheeling Schottky diode is much higher than the on-state voltage drop of the MOSFET tube, the energy loss in the loop can be effectively reduced. For example, when the on-state voltage drop of the freewheeling Schottky diode is 0.7V and the current in the loop is 3A, the loss of the freewheeling Schottky diode is 2.1W; when the internal resistance of the MOSFET tube is 10mΩ and the current in the loop is 3A, the loss of the MOSFET tube is 0.09W. It can be seen from the comparison that replacing the freewheeling Schottky diode in the flyback converter with a MOSFET tube can effectively reduce the energy loss in the loop and improve the efficiency of the flyback converter.

[0048] In the related art, there are usually two ways to implement a synchronous rectification controller based on a MOSFET tube. The first way is described in Figure 2 , Figure 2 A flyback converter with a synchronous rectification controller is provided in the related art, such as Figure 2 As shown, the MOSFET tube and the synchronous rectifier controller are separate, and the synchronous rectifier controller can be used to control the on or off of the MOSFET tube. Figure 3 , Figure 3A flyback converter with a synchronous rectification controller integrated with a MOSFET tube is provided in the related art, such as Figure 3 As shown in the figure, this method integrates the MOSFET tube into the synchronous rectification controller, and also controls the on or off of the MOSFET tube through the synchronous rectification controller. The difference between the two methods is that in the first method, the MOSFET tube and the synchronous rectification controller are separate, while in the second method, the MOSFET tube and the synchronous rectification controller are integrated together.

[0049] The synchronous rectifier controller (SR) collects the feedback voltage Vsen, analyzes the collected results, and controls the on or off of the MOSFET tube according to the analysis results. The internal circuit of the synchronous rectifier controller includes a high-voltage circuit part and a low-voltage circuit part, which are manufactured using different processes according to different voltages. For example, for the 100V voltage part, a high-voltage process is required to be manufactured, and for the 5V voltage part, a low-voltage process is required to be manufactured. The synchronous rectifier controller needs to be manufactured using two processes during the production process, namely the high-voltage process and the low-voltage process. The high-voltage process is more expensive than the low-voltage process, which makes the production cost of the synchronous rectifier controller very high.

[0050] In order to reduce the manufacturing cost of a synchronous rectification controller, the present application provides an integrated synchronous rectification controller, a flyback converter and an electronic device.

[0051] The integrated synchronous rectification controller may be a chip or a circuit module.

[0052] The flyback converter may include an integrated synchronous rectification controller.

[0053] In this application, electronic devices may include, but are not limited to: adapters, chargers, tablet computers, smart home devices, vehicles, and wearable devices.

[0054] See also Figure 4 , Figure 4 An integrated synchronous rectification controller 1000 provided in an embodiment of the present application is as follows: Figure 4As shown, the integrated synchronous rectification controller 1000 may include: a first switch tube 100 and a synchronous rectification controller 200, wherein the control end of the first switch tube 100 is electrically connected to the synchronous rectification controller 200; the synchronous rectification controller 200 includes: a sampling circuit 201, a transistor 202, a power supply circuit 203, a detection circuit 204 and a logic control circuit 205; the first switch tube 100, the sampling circuit 201 and the transistor 202 are arranged on a first bare chip; the power supply circuit 203, the detection circuit 204 and the logic control circuit 205 are arranged on a second bare chip; wherein the first bare chip is manufactured using a high-voltage process, and the second bare chip is manufactured using a low-voltage process.

[0055] The synchronous rectification controller 200 is used to control the on or off of the first switch tube 100 .

[0056] The integrated synchronous rectification controller in the present application is formed by sealing a first switch tube and a synchronous rectification controller, the integrated synchronous rectification controller is electrically connected to the control end of the first switch tube, and the conduction or shutdown of the first switch tube is controlled by the synchronous rectification controller. The synchronous rectification controller includes: a sampling circuit, a transistor, a power supply circuit, a detection circuit and a logic control circuit; wherein the sampling circuit and the transistor belong to the high-voltage circuit part of the synchronous rectification controller, and the power supply circuit, the detection circuit and the logic control circuit belong to the low-voltage circuit part of the synchronous rectification controller.

[0057] During the manufacturing process of the integrated synchronous rectification controller, the first switch tube is the high-voltage circuit part, and the bare chip where the first switch tube is located needs to be manufactured using a high-voltage process; the internal circuit of the synchronous rectification controller includes a high-voltage circuit part and a low-voltage circuit part. For the high-voltage circuit part, a high-voltage process needs to be used for manufacturing, and for the low-voltage circuit part, a low-voltage process needs to be used for manufacturing. Therefore, when the internal circuit of the synchronous rectification controller includes a high-voltage circuit part and a low-voltage circuit part, the bare chip where the synchronous rectification controller is located needs to be manufactured using two processes.

[0058] Different processes need to be adopted for different power supply voltages. Usually, in the CMOS process, a low-voltage process (i.e., LV-CMOS) is used for an operating voltage of 1V to 5V, and a high-voltage process (i.e., HV-CMOS) is used for a voltage of 12V to 40V or even higher. Of course, the critical voltage values ​​of low voltage and high voltage may be different for different types of processes. For example, for the BCD (Bipolar-CMOS-DMOS) process, the low voltage range is 1V to 5V, and the high voltage range is above 6V. The specific definitions of high and low voltages are determined by the industry standards or experience of the semiconductor manufacturing process, and this application does not limit this. In the preparation process of the high-voltage process, the breakdown voltage is mainly increased by increasing the thickness of the gate oxide layer of the switch tube, increasing the device size, increasing the isolation layer, using a lightly doped drain (LDD) structure and other drain engineering methods.

[0059] In the integrated synchronous rectification controller of the present application, the sampling circuit and transistor in the synchronous rectification controller are arranged on the first bare chip where the first switch tube is located, that is, the first switch tube, the sampling circuit and the transistor are arranged on the first bare chip. Since the first switch tube is a high-voltage circuit part, the first bare chip where the first switch tube is located needs to be manufactured using a high-voltage process. The high-voltage circuit part (that is, the sampling circuit and the transistor) in the synchronous rectification controller is arranged on the first bare chip, so that only the low-voltage circuit part remains in the synchronous rectification controller, and the low-voltage circuit (that is, the power supply circuit, the detection circuit and the logic control circuit) is arranged on the second bare chip where the synchronous rectification controller is located, so that the second bare chip only needs to be manufactured using a low-voltage process.

[0060] In the embodiment of the present application, the high-voltage circuit part in the synchronous rectification controller is arranged on the first bare chip that needs to adopt the high-voltage process, and the low-voltage circuit part in the synchronous rectification controller is arranged on the second bare chip, so as to realize the separation of the high-voltage circuit part and the low-voltage circuit part in the synchronous rectification controller, so that the second bare chip only needs to be manufactured by the low-voltage process. Compared with the synchronous rectification controller including the high-voltage circuit part and the low-voltage circuit part, which needs to be manufactured by both the high-voltage process and the low-voltage process, the synchronous rectification controller in the integrated synchronous rectification controller provided by the present application only needs to adopt the low-voltage process, which can reduce the manufacturing cost of the synchronous rectification controller and further reduce the dependence on the process.

[0061] In one possible embodiment, see Figure 5 ,like Figure 5As shown, the input end of the transistor 202 is electrically connected to the feedback voltage end, and the output end of the transistor 202 is electrically connected to the input end of the sampling circuit 201 and the input end of the power supply circuit 203 respectively; the output end of the sampling circuit 201 is electrically connected to the first input end of the detection circuit 204; the output end of the power supply circuit 203 is electrically connected to the second input end of the detection circuit 204 and the first input end of the logic control circuit 205 respectively; the output end of the detection circuit 204 is electrically connected to the second input end of the logic control circuit 205; the output end of the logic control circuit 205 is electrically connected to the control end of the first switch tube 100.

[0062] The transistor 202 is used for clamping the feedback voltage Vsen connected to the feedback voltage terminal, outputting the clamped voltage, and transmitting the clamped voltage to the sampling circuit 201 and the power supply circuit 203 respectively.

[0063] The power supply circuit 203 is used to receive the clamping voltage, charge itself, and provide power for the detection circuit 204 and the logic control circuit 205;

[0064] The sampling circuit 201 is used to collect the clamping voltage, output a voltage signal, and transmit the voltage signal to the detection circuit 204 .

[0065] The detection circuit 204 is used to process the voltage signal, output a control signal, and transmit the control signal to the logic control circuit 205 .

[0066] The logic control circuit 205 is used to control the on or off of the first switch tube 100 according to the control signal.

[0067] The feedback voltage Vsen is usually a high voltage with a voltage range of 65V to 120V. In one example, the feedback voltage Vsen can be 100V. In actual project applications, it is usually necessary to convert the high voltage into a low voltage to facilitate the processing of the subsequent circuit. The transistor is used to clamp the feedback voltage Vsen connected to the feedback voltage terminal, and clamp the feedback voltage Vsen at a suitable voltage level. In one example, the transistor clamps the feedback voltage Vsen, and the output clamping voltage is 30V. The clamping voltage is transmitted to the sampling circuit 201 and the power supply circuit 203 for sampling and charging respectively.

[0068] The power supply circuit can charge itself based on the received clamping voltage and perform level conversion to provide the required power for the detection circuit and the logic control circuit. In one example, the power supply circuit can convert 8VDC into 5VDC or 3.3VDC to provide power for the detection circuit and the logic control circuit.

[0069] In one possible embodiment, see Figure 6 , Figure 6A circuit structure diagram of a sampling circuit provided in an embodiment of the present application is shown in FIG. Figure 6 As shown, the sampling circuit 201 includes: a first resistor R1 and a second resistor R2.

[0070] The first end of the first resistor R1 is electrically connected to the output end of the transistor 202 , and the second end of the first resistor R1 is electrically connected to the first end of the second resistor R2 and the input end of the detection circuit 204 .

[0071] A second end of the second resistor R2 is grounded.

[0072] The output end of the transistor outputs a clamping voltage, the sampling circuit is used to collect the clamping voltage, divide the clamping voltage through the first resistor and the second resistor to obtain a voltage signal, and transmit the voltage signal to the detection circuit.

[0073] In a specific embodiment, when the clamping voltage is a high voltage signal and the divided voltage on the first resistor and the second resistor is also a high voltage signal, the sampling circuit is disposed on the first bare chip and needs to be manufactured using a high voltage process.

[0074] In a specific embodiment, when the clamping voltage is a high-voltage signal, the divided voltage on the first resistor is a high-voltage signal, and the divided voltage on the second resistor is a low-voltage signal, the first resistor in the sampling circuit can be set on the first bare chip, which needs to be manufactured using a high-voltage process, and the second resistor in the sampling circuit can be set on the second bare chip, which needs to be manufactured using a low-voltage process.

[0075] In a possible embodiment, the transistor is a junction field effect transistor.

[0076] The transistor is a Junction Field-Effect Transistor (JFET), which clamps the feedback voltage Vsen connected to the feedback voltage terminal and outputs the clamped voltage. Since the feedback voltage Vsen is a high-voltage signal, the transistor needs to be manufactured using a high-voltage process.

[0077] In a possible embodiment, the first switch tube is a MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor).

[0078] The present application embodiment provides a flyback converter, see Figure 5 , Figure 5 A flyback converter is provided in an embodiment of the present application, such as Figure 5As shown, the flyback converter includes: an integrated synchronous rectification controller 1000, a switch circuit 300, a voltage conversion circuit 400 and an output filter circuit 500; the voltage conversion circuit 400 includes a primary winding and a secondary winding.

[0079] The input end of the switch circuit 300 is used to access the input energy Vin, the first output end of the switch circuit 300 is electrically connected to the first input end of the transformer circuit 400, and the second output end of the switch circuit 300 is electrically connected to the second input end of the transformer circuit 400; the first output end of the transformer circuit 400 is electrically connected to the input end of the output filter circuit 500 and the output end of the output filter circuit 500 respectively, and the second output end of the transformer circuit 400 is electrically connected to the input end of the integrated synchronous rectification controller 1000; the output end of the integrated synchronous rectification controller 1000 is grounded;

[0080] When the switch circuit 300 is turned on, the voltage transformation circuit 400 is used to store the received input energy Vin in the primary winding to obtain stored energy.

[0081] When the switch circuit 300 is turned off, the transformer circuit 400 is used to transfer the stored energy to the secondary winding, so that the stored energy is rectified and filtered through the integrated synchronous rectification controller 1000 and the output filter circuit 500 and converted into the output voltage Vout.

[0082] Flyback converter is a switching power supply topology, widely used in AC / DC and DC / DC conversion, and provides insulation isolation between the input and output stages. It is a type of switching power supply. Its application range includes low-power switching power supplies, high-voltage power supplies for cathode ray tubes, and insulated gate drivers. It has the advantages of simple structure and wide application.

[0083] The operation of the flyback converter can be divided into two stages: the switch circuit conduction stage and the switch circuit shutdown stage.

[0084] In one possible embodiment, see Figure 5 ,like Figure 5 As shown, the switch circuit 300 includes: a first capacitor C1, a third resistor R3, a diode D1 and a second switch tube Q1.

[0085] The first end of the first capacitor C1 is electrically connected to the first end of the third resistor R3, the input end of the switch circuit 300, and the first output end of the switch circuit 300 respectively; the input end of the switch circuit 300 is used to access the input energy Vin.

[0086] The second end of the first capacitor C1 is electrically connected to the second end of the third resistor R3 and the first end of the diode D1 respectively.

[0087] The second end of the diode D1 is electrically connected to the first end of the second switch tube Q1 and the second output end of the switch circuit 300 respectively.

[0088] A second terminal of the second switch tube Q1 is grounded, and a control terminal of the second switch tube Q1 is used to access a PWM signal.

[0089] The PWM (Pulse width modulation) signal connected to the control end of the second switch tube in the embodiment of the present application is generated by a PWM generation circuit. The PWM signal enables the second switch tube to be turned on or off at a certain frequency. Since this is the prior art, it will not be repeated in this application.

[0090] In one possible embodiment, see Figure 5 ,like Figure 5 As shown, the voltage transformation circuit 400 includes: a transformer T1.

[0091] A first tap of the primary winding of the transformer T1 is electrically connected to a first output terminal of the switch circuit 300 , and a second tap of the primary winding of the transformer T1 is electrically connected to a second output terminal of the switch circuit 300 .

[0092] A first tap of the secondary winding of the transformer T1 is electrically connected to the input end of the output filter circuit 500 , and a second tap of the secondary winding of the transformer T1 is electrically connected to the input end of the synchronous rectification controller 1000 .

[0093] A transformer is a device that uses the principle of electromagnetic induction to change AC voltage. Its main components are a primary coil (or primary winding), a secondary coil (or secondary winding), and an iron core (magnetic core). The main functions of a transformer include: voltage conversion, current conversion, impedance conversion, isolation, voltage stabilization (magnetic saturation transformer), etc. The function of the transformer in the embodiment of the present application is to perform voltage conversion.

[0094] In one possible embodiment, see Figure 5 ,like Figure 5 As shown, the output filter circuit 500 includes: a second capacitor C2.

[0095] A first end of the second capacitor C2 is electrically connected to an input end of the output filter circuit 500 and an output end of the output filter circuit 500 , respectively, and a second end of the second capacitor C2 is grounded.

[0096] The output filter circuit mainly filters the DC output voltage Vout through the second capacitor.

[0097] An embodiment of the present application further provides an electronic device, including: the above-mentioned flyback converter.

[0098] Finally, it should be noted that the above embodiments are only specific implementation methods of the present application, but the protection scope of the present application is not limited thereto, and any changes or substitutions within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. An integrated synchronous rectification controller, characterized in that: The integrated synchronous rectification controller comprises: a first switch tube and a synchronous rectification controller, wherein the control end of the first switch tube is electrically connected to the synchronous rectification controller; The synchronous rectification controller includes: a sampling circuit, a transistor, a power supply circuit, a detection circuit and a logic control circuit; the first switch tube, the sampling circuit and the transistor are arranged on a first bare chip; the power supply circuit, the detection circuit and the logic control circuit are arranged on a second bare chip; wherein the first bare chip is manufactured by a high-voltage process, and the second bare chip is manufactured by a low-voltage process; The synchronous rectification controller is used to control the on or off of the first switch tube.

2. The integrated synchronous rectification controller according to claim 1, characterized in that: The input end of the transistor is electrically connected to the feedback voltage end, and the output end of the transistor is electrically connected to the input end of the sampling circuit and the input end of the power supply circuit respectively; the output end of the sampling circuit is electrically connected to the first input end of the detection circuit; the output end of the power supply circuit is electrically connected to the second input end of the detection circuit and the first input end of the logic control circuit respectively; the output end of the detection circuit is electrically connected to the second input end of the logic control circuit; the output end of the logic control circuit is electrically connected to the control end of the first switch tube; The transistor is used to clamp the feedback voltage connected to the feedback voltage terminal, output the clamped voltage, and transmit the clamped voltage to the sampling circuit and the power supply circuit respectively; The power supply circuit is used to receive the clamping voltage, charge itself, and provide power for the detection circuit and the logic control circuit; The sampling circuit is used to collect the clamping voltage, output a voltage signal, and transmit the voltage signal to the detection circuit; The detection circuit is used to process the voltage signal, output a control signal, and transmit the control signal to the logic control circuit; The logic control circuit is used to control the on or off of the first switch tube according to the control signal.

3. The integrated synchronous rectification controller according to claim 2, characterized in that: The sampling circuit comprises: a first resistor and a second resistor; The first end of the first resistor is electrically connected to the output end of the transistor, and the second end of the first resistor is electrically connected to the first end of the second resistor and the input end of the detection circuit respectively; A second terminal of the second resistor is grounded.

4. The integrated synchronous rectification controller according to claim 1 or 2, characterized in that: The transistor is a junction field effect transistor.

5. The integrated synchronous rectification controller according to claim 1 or 2, characterized in that: The first switch tube is a MOSFET tube.

6. A flyback converter, characterized in that: The flyback converter comprises: an integrated synchronous rectification controller as claimed in any one of claims 1 to 5, further comprising a switching circuit, a voltage conversion circuit and an output filtering circuit; the voltage conversion circuit comprises a primary winding and a secondary winding; The input end of the switch circuit is used to access input energy, the first output end of the switch circuit is electrically connected to the first input end of the transformer circuit, and the second output end of the switch circuit is electrically connected to the second input end of the transformer circuit; the first output end of the transformer circuit is electrically connected to the input end of the output filter circuit and the output end of the output filter circuit respectively, and the second output end of the transformer circuit is electrically connected to the input end of the integrated synchronous rectification controller; the output end of the integrated synchronous rectification controller is grounded; When the switch circuit is turned on, the voltage conversion circuit is used to store the received input energy in the primary winding to obtain stored energy; When the switch circuit is turned off, the voltage conversion circuit is used to transfer the stored energy to the secondary winding, so that the stored energy is rectified and filtered by the integrated synchronous rectification controller and the output filter circuit and converted into an output voltage.

7. The flyback converter according to claim 6, characterized in that: The switch circuit comprises: a first capacitor, a third resistor, a diode and a second switch tube; The first end of the first capacitor is electrically connected to the first end of the third resistor, the input end of the switch circuit, and the first output end of the switch circuit respectively; the input end of the switch circuit is used to access the input energy; The second end of the first capacitor is electrically connected to the second end of the third resistor and the first end of the diode respectively; The second end of the diode is electrically connected to the first end of the second switch tube and the second output end of the switch circuit respectively; The second end of the second switch tube is grounded, and the control end of the second switch tube is used to access the PWM signal.

8. The flyback converter according to claim 6, characterized in that: The voltage conversion circuit comprises: a transformer; A first tap of the primary winding of the transformer is electrically connected to a first output terminal of the switch circuit, and a second tap of the primary winding of the transformer is electrically connected to a second output terminal of the switch circuit; A first tap of the secondary winding of the transformer is electrically connected to an input end of the output filter circuit, and a second tap of the secondary winding of the transformer is electrically connected to an input end of the synchronous rectification controller.

9. The flyback converter according to claim 6, characterized in that: The output filter circuit comprises: a second capacitor; A first end of the second capacitor is electrically connected to an input end of the output filter circuit and an output end of the output filter circuit respectively, and a second end of the second capacitor is grounded.

10. An electronic device, characterized in that: include: A flyback converter as claimed in any one of claims 6 to 9.

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