A starting control circuit and electronic device

Abstract

The application relates to the technical field of power supply soft starting, in particular to a starting control circuit and electronic equipment. The starting control circuit comprises a main control module, a first switch module and a second switch module. The main control module is used for realizing driving control of the starting control circuit, and is configured to output a starting control signal after a preset delay time in response to access of an external power supply; the first switch module is arranged in a power supply loop between the external power supply and a powered load, and is used for controlling the conduction state of the power supply loop; the second switch module is connected with the main control module and the first switch module, a control end of the second switch module accesses the starting control signal, and the second switch module is configured to be turned on after receiving the starting control signal and control the first switch module to be turned on. The starting control circuit can improve the stability of circuit starting power supply.

Description

Technical Field

[0001] This application relates to the field of power supply soft-start technology, and in particular to a start-up control circuit and electronic device. Background Technology

[0002] PoE (Power over Ethernet) technology is a technology that transmits both data and power simultaneously over Ethernet cables (such as Cat5e and Cat6). It allows network devices (such as IP cameras, wireless access points, and VoIP phones) to be powered directly through the network cable without additional power cords, thus simplifying cabling, reducing costs, and improving deployment flexibility. With the widespread application of PoE technology, efficient and secure power transmission between power supply equipment (PSE) and powered devices (PD) has become a critical requirement. The PoE controller chip, as the core management unit, is responsible for power negotiation, hierarchical detection, and power supply control; the stability of its startup process directly affects system reliability.

[0003] In related technologies, Power over Ethernet (PoE) controller chips are currently widely used in consumer electronics products powered by power supplies with network interfaces. In traditional architectures, controllers typically employ a hard-start approach, applying full voltage directly after detecting a valid powered device.

[0004] However, the current startup control circuit has the following technical problems:

[0005] Currently, the startup control method based on hard-start architecture can cause a large overshoot voltage at the power supply output at the moment of power-on, which may cause a momentary drop in line voltage and interfere with other devices in the same network; it can also increase the stress on MOSFET switches, shorten device lifespan; and it can cause frequent triggering of system protection circuits, reducing power supply efficiency. These issues need to be optimized. Utility Model Content

[0006] Therefore, it is necessary to provide a startup control circuit and electronic device that can improve the stability of startup power supply and enhance the stability of product circuits.

[0007] This application provides a start-up control circuit and an electronic device.

[0008] In a first aspect, this application provides a startup control circuit, including:

[0009] A first switch module has a first terminal, a second terminal and a control terminal. The first terminal of the first switch module is coupled to a power supply, and the second terminal of the first switch module is coupled to a power supply terminal between the powered load.

[0010] The second switch module has a first terminal, a second terminal and a control terminal. The first terminal of the second switch module is coupled to the control terminal of the first switch module, and the second terminal of the second switch module is coupled to a reference ground.

[0011] The main control module is connected to the control terminal of the power supply and the second switch module. The main control module is configured to output a start control signal after a delay in response to the power supply being turned on, wherein the start control signal is used to turn on the second switch module.

[0012] In one embodiment, the first switching module includes a first switching transistor and a second switching transistor. Both the first switching transistor and the second switching transistor include an input terminal, an output terminal, and a control terminal. The input terminal of the first switching transistor is coupled to the input terminal of the second switching transistor, the output terminal of the first switching transistor is coupled to the output terminal of the second switching transistor, and the control terminal of the first switching transistor is coupled to the control terminal of the second switching transistor.

[0013] The control terminal of the first switch is also coupled to the input terminal of the first switch, and the control terminal of the second switch is also coupled to the input terminal of the second switch.

[0014] In one embodiment, the second switching module (300) includes a third switching transistor, which includes an input terminal, an output terminal, and a control terminal. The control terminals of the first and second switching transistors are both coupled to the output terminal of the third switching transistor. The input terminals of the first and second switching transistors are both coupled to the output terminal of the power supply. The output terminals of the first and second switching transistors are both coupled to the input terminal of the powered load.

[0015] The control terminal of the third switch is coupled to the main control module (100), and the input terminal of the third switch is coupled to reference ground.

[0016] In one embodiment, the first switching module further includes a first resistor having a first terminal and a second terminal. The first terminal of the first resistor is coupled to the control terminal of both the first switching transistor and the second switching transistor, and the second terminal of the first resistor is coupled to the input terminal of both the first switching transistor and the second switching transistor.

[0017] In one embodiment, the first switching module further includes a first capacitor having a first terminal and a second terminal. The first terminal of the first capacitor is coupled to the output terminal of both the first switching transistor and the output terminal of both the second switching transistor, and the second terminal of the first capacitor is coupled to the input terminal of both the first switching transistor and the input terminal of both the second switching transistor.

[0018] In one embodiment, a second resistor is provided between the first switch module and the second switch module. The second resistor has a first end and a second end. The first end of the second resistor is coupled to the control end of both the first switch and the second switch, and the second end of the second resistor is coupled to the output end of the third switch.

[0019] In one embodiment, the startup control circuit further includes:

[0020] A current detection module is coupled to the power supply circuit between the first switch module and the powered load, and the current detection module is used to detect the current value on the power supply circuit.

[0021] The main control module is also connected to the current detection module and receives the current value detected by the current detection module. The main control module is used to compare the current value with a preset value and is configured to output a shutdown signal when the current value is greater than the preset value. The shutdown signal is used to shut down the second switch module.

[0022] In one embodiment, the current detection module includes:

[0023] A sampling resistor is connected in series in the power supply circuit between the first switching module and the powered load;

[0024] An operational amplifier has a first input terminal, a second input terminal, and an output terminal. The first input terminal of the operational amplifier is coupled to the first terminal of the sampling resistor, the second input terminal of the operational amplifier is coupled to the second terminal of the sampling resistor, and the output terminal of the operational amplifier is coupled to the main control module.

[0025] In one embodiment, the current detection module further includes:

[0026] A filtering unit, disposed between the sampling resistor and the operational amplifier, is used to filter the differential voltage signal acquired by the operational amplifier. The filtering unit includes:

[0027] A first filter resistor has a first terminal and a second terminal. The first terminal of the first filter resistor is coupled to the first terminal of the sampling resistor, and the second terminal of the first filter resistor is coupled to the first input terminal of the operational amplifier.

[0028] The second filter resistor has a first terminal and a second terminal. The first terminal of the second filter resistor is coupled to the second terminal of the sampling resistor, and the second terminal of the second filter resistor is coupled to the second input terminal of the operational amplifier.

[0029] A filter capacitor has a first terminal and a second terminal. The first terminal of the filter capacitor is coupled to the first terminal of the first filter resistor, and the second terminal of the filter capacitor is coupled to the second terminal of the second filter resistor.

[0030] Secondly, this application also provides an electronic device, including a start-up control circuit according to any one of the first aspects.

[0031] The aforementioned start-up control circuit and electronic device, derived from the technical features in the claims, can achieve the following beneficial effects to address the technical problems raised in the background art:

[0032] This application provides a startup control circuit, including a main control module, a first switch module, and a second switch module. The first switch module has a first terminal, a second terminal, and a control terminal. The first terminal of the first switch module is coupled to a power supply, and the second terminal is coupled to a power supply terminal between the powered load and the power source. The second switch module has a first terminal, a second terminal, and a control terminal. The first terminal of the second switch module is coupled to the control terminal of the first switch module, and the second terminal is coupled to a reference ground. The main control module is connected to the power supply and the control terminal of the second switch module. The main control module is configured to output a startup control signal with a delay in response to the power supply being turned on. The startup control signal is used to turn on the second switch module. In implementation, through the preset configuration of the main control module, a preset-delayed startup control signal is provided in response to the external power supply. At this time, the startup control signal triggers the second switch module to turn on, thereby causing the first switch module to turn on successively. This forms a delayed-triggered, two-stage switching power supply control architecture, realizing soft-start power supply for the powered load, helping to suppress inrush current during power-on scenarios, reducing the negative impact of power-on shocks on product devices, and thus improving circuit stability. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments of this application or the conventional technology, the drawings used in the description of the embodiments or the conventional technology will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1 This is a schematic diagram of the architecture of a startup control circuit in an embodiment of this application;

[0035] Figure 2 This is a schematic diagram of the architecture of a startup control circuit in another embodiment of this application;

[0036] Figure 3This is a schematic diagram of the connection of a start-up control circuit in one embodiment of this application.

[0037] Explanation of reference numerals in the attached figures:

[0038] 100. Main control module; 200. First switch module; 300. Second switch module; 400. Current detection module; 410. Filtering unit; 500. Powered load;

[0039] Q1, first switching transistor; Q2, second switching transistor; Q3, third switching transistor; R1, first resistor; R2, second resistor; C1, first capacitor; R3, sampling resistor; R6, first filter resistor; R7, second filter resistor; C3, filter capacitor. Detailed Implementation

[0040] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings, which illustrate embodiments of the present application. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of this application will be thorough and complete.

[0041] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0042] It is understood that the terms "first," "second," etc., used herein may be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish one element from another. For example, without departing from the scope of this application, a first resistor may be referred to as a second resistor, and similarly, a second resistor may be referred to as a first resistor. Both the first resistor and the second resistor are resistors, but they are not the same resistor.

[0043] It is understood that the term "connection" in the following embodiments should be understood as "electrical connection," "communication connection," etc., if the connected circuits, modules, units, etc., have electrical signal or data transmission with each other.

[0044] It is understandable that "at least one" refers to one or more, and "multiple" refers to two or more. "At least a part of an element" refers to part or all of an element.

[0045] When used herein, the singular forms of “a,” “an,” and “the” may also include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising / including” or “having,” etc., specify the presence of the stated features, wholes, steps, operations, components, parts, or combinations thereof, but do not preclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof. Meanwhile, the term “and / or” as used in this specification includes any and all combinations of the associated listed items.

[0046] As mentioned in the background section, current common startup power supply control circuits still need optimization.

[0047] This application is based on the inventor's understanding and research on the following issues, specifically:

[0048] Currently, the startup control method based on hard-start architecture can cause a large overshoot voltage at the power supply output at the moment of power-on, which may cause a momentary drop in line voltage and interfere with other devices in the same network; it can also increase the stress on MOSFET switches, shorten device lifespan; and it can cause frequent triggering of system protection circuits, reducing power supply efficiency. These issues need to be optimized.

[0049] To address the aforementioned problems, this application provides a startup control circuit that can, as follows: Figure 1 As shown, Figure 1 The diagram shows a schematic of the architecture of a startup control circuit according to an embodiment of this application. The startup control circuit provided in this embodiment includes a main control module 100, a first switch module 200, and a second switch module 300.

[0050] The main control module 100 is used to drive the start control circuit. The main control module 100 is configured to output a start control signal after a preset delay time in response to the access of an external power supply.

[0051] For example, the main control module 100 can be the drive control center of the startup control circuit. In this embodiment, it is mainly used to detect the external power supply input signal and output a startup control signal after a preset delay interval, thereby achieving the purpose of delayed triggering. The delayed triggering of the main control module 100 can also be based on existing delay programs, as long as it can output a startup control signal after a set delay interval after the external power supply is connected. The main functions of the main control module 100 mainly include power detection and delay control. The main control module 100 can be implemented based on programmable logic devices, microcontrollers, delay circuits, dedicated power management chips, etc. The specific implementation method can be determined by technicians according to the actual application scenario.

[0052] For example, the main control module 100 is primarily used to send a start control signal after a preset delay following the detection of external power supply access or the detection of power supply voltage. Specifically, when external power supply accesses the main control module, an indication signal is generated to confirm the access. The scenario where the main control module 100 detects power supply voltage indicates that the external power supply has started operating and is outputting a voltage signal to the main control module. For example, the delay time can be 0.1 seconds, 0.5 seconds, 1 second, etc., and the specific delay time can be determined by technicians based on the application scenario. The start control signal can refer to the control command output by the main control module 100, used to trigger lower-level circuit modules, such as the second switch module 300. The start control signal can be a level trigger signal, an edge trigger signal, a pulse trigger signal, a differential trigger signal, etc.

[0053] In one embodiment, taking a microcontroller as the main control module 100 as an example, the microcontroller has an independent power supply circuit, and the trigger delay time can be preset to 0.5 seconds in the microcontroller. When the external power supply is not connected or no power supply is detected to start working and output a voltage signal to the main control module 100, the microcontroller's MCU-IO port outputs a level signal indicating that the second switch module 300 is turned off. In one embodiment, this level signal is low. When the external power supply is connected or the power supply is detected to start working and output a voltage signal to the main control module 100, the microcontroller triggers and outputs a level signal indicating that the second switch module 300 is turned on through the MCU-IO port after a preset delay interval of 0.5 seconds. In one embodiment, this level signal is high, thus realizing the delay control of the second switch module 300. In other embodiments, the level signal indicating that the second switch module 300 is turned off can also be high, and conversely, the level signal indicating that the second switch module 300 is turned on is low.

[0054] The first switch module 200 is located in the power supply circuit between the external power source and the powered load 500. The first switch is used to control the conduction state of the power supply circuit.

[0055] For example, the first switch module 200 can be an execution module in the start control circuit that controls the on / off state of the power supply circuit. In one embodiment, the control command output by the main control module 100 may include a start control signal, and the first switch module 200 can turn on the power supply circuit between the external power source and the powered load 500 according to the start control signal. In another embodiment, the control command output by the main control module 100 may also include a stop control signal, and the first switch module 200 can also turn off the power supply circuit between the external power source and the powered load 500 according to the stop control signal.

[0056] For example, the first switching module 200 can be implemented based on various switching devices, such as mechanical switches, like relays; semiconductor switches, such as MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors) and IGBTs (Insulated Gate Bipolar Transistors); and intelligent integrated switches, such as load switch ICs. The first switching module 200 can be any one of the above exemplary embodiments, or a combination of multiple of the above exemplary embodiments.

[0057] The second switch module 300 is connected to both the main control module 100 and the first switch module 200. The control terminal of the second switch module 300 is connected to the start control signal. The second switch module 300 is configured to turn on after receiving the start control signal and control the first switch module 200 to turn on.

[0058] For example, the second switch module 300 can be a front-end execution module in the start-up control circuit that controls the on / off state of the power supply circuit. In one embodiment, the control command output by the main control module 100 may include a start control signal, and the second switch module 300 can control the first switch module 200 to turn on according to the start control signal. In another embodiment, the control command output by the main control module 100 may also include a stop control signal, and the second switch module 300 can also control the first switch module 200 to turn off according to the stop control signal. Thus, structurally, the first switch module 200 and the second switch module 300 cooperate to form a two-stage trigger switch.

[0059] For example, the second switching module 300 can be implemented based on various switching devices, such as mechanical switches, like relays; semiconductor switches, such as MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors) and IGBTs (Insulated Gate Bipolar Transistors); and intelligent integrated switches, such as load switch ICs. The second switching module 300 can be any one of the exemplary embodiments described above, or a combination of multiple exemplary embodiments described above.

[0060] By implementing the above-described start-up control circuit, the following beneficial effects can be achieved:

[0061] This application provides a startup control circuit, including a main control module 100, a first switch module 200, and a second switch module 300. The main control module 100 is used to drive and control the startup control circuit. The main control module 100 is configured to output a startup control signal after a preset delay time in response to the access of an external power source. The first switch module 200 is located in the power supply circuit between the external power source and the powered load 500, and the first switch is used to control the conduction state of the power supply circuit. The second switch module 300 is connected to the main control module 100 and the first switch module 200. The control terminal of the second switch module 300 receives the startup control signal. The second switch module 300 is configured to conduct upon receiving the startup control signal and control the first switch module 200 to conduct. In implementation, through the preset configuration of the main control module 100, a startup control signal with a preset delay is provided in response to the access of an external power source. At this time, the startup control signal triggers the second switch module 300 to conduct, thereby causing the first switch module 200 to conduct sequentially. This forms a delayed-triggered, two-stage switching power supply control architecture, enabling soft-start power supply for 500V power-received loads. This helps suppress surge current during power-on scenarios, reduces the negative impact of power-on shocks on product components, and thus improves circuit stability.

[0062] In one embodiment, it can be as follows Figure 3 As shown, Figure 3 The diagram shows a connection schematic of a start-up control circuit according to an embodiment of this application. The first switch module 200 includes a first switch transistor Q1 and a second switch transistor Q2. Both the first switch transistor Q1 and the second switch transistor Q2 include an input terminal, an output terminal, and a control terminal. The input terminal of the first switch transistor Q1 is coupled to the input terminal of the second switch transistor Q2, the output terminal of the first switch transistor Q1 is coupled to the output terminal of the second switch transistor Q2, and the control terminal of the first switch transistor Q1 is coupled to the control terminal of the second switch transistor Q2. The control terminal of the first switch transistor Q1 is also coupled to the input terminal of the first switch transistor Q1, and the control terminal of the second switch transistor Q2 is also coupled to the input terminal of the second switch transistor Q2.

[0063] In one embodiment, the first switch Q1 can be a P-channel field-effect transistor (PMOS), which has a gate terminal G, a source terminal S, and a drain terminal D. In this embodiment, the input terminal of the first switch Q1 is the source S, the control terminal is the gate G, and the output terminal is the drain D. In another embodiment, the first switch Q1 can be an N-channel field-effect transistor (NMOS), where the input terminal is the source S, the control terminal is the gate G, and the output terminal is the drain D.

[0064] In one embodiment, the second switch Q2 can be an N-channel field-effect transistor (NMOS), which has a gate terminal G, a source terminal S, and a drain terminal D. In this embodiment, the input terminal of the second switch Q2 is the source S, the control terminal is the gate G, and the output terminal is the drain D. In another embodiment, the second switch Q2 can be an N-channel field-effect transistor (NMOS), and in this embodiment, the input terminal of the second switch Q2 is the source S, the control terminal is the gate G, and the output terminal is the drain D.

[0065] For example, in the application of delayed triggering based on this application, both the first switch Q1 and the second switch Q2 can be selected as P-channel field-effect transistors (PMOS). A P-channel field-effect transistor (PMOS) is composed of a P-type channel (source S and drain D) and an N-type substrate, and the gate G controls the channel on and off through an insulating layer.

[0066] In one embodiment, the control terminals of the first switch Q1 and the second switch Q2 are both coupled to the first terminal of the second switch module 300, the input terminals of the first switch Q1 and the second switch Q2 are both coupled to the output terminal of the power supply, and the output terminals of the first switch Q1 and the second switch Q2 are both coupled to the input terminal of the powered load 500.

[0067] In one embodiment, the second switching module 300 may include a third switching transistor Q3, which may be a transistor and includes an output terminal, a control terminal, and a base B, a collector C, and an emitter E. The base B serves as the control terminal of the third switching transistor Q3 and is connected to the main control module 100. The collector C serves as the output terminal of the third switching transistor Q3 and is coupled to the control terminals of the first switching transistor Q1 and the second switching transistor Q2. The emitter E serves as the input terminal of the third switching transistor Q3 and is coupled to a reference ground.

[0068] It should be noted that this embodiment only uses PMOS as one possible implementation of the second switching module 300, and uses this as an example for illustration. The implementation using other switching devices is similar and will not be described in detail.

[0069] In a specific example, the gate terminal G of the first switch Q1 and the gate terminal G of the second switch Q2 are both connected to the second switch module 300, the source terminal S of the first switch Q1 and the source terminal S of the second switch Q2 are both connected to an external power supply, and the drain terminal D of the first switch Q1 and the drain terminal D of the second switch Q2 are both connected to the powered load 500.

[0070] In this embodiment, the scheme of constructing the first switching module 200 based on field-effect transistors (FETs) utilizes the turn-on characteristics of FETs to control the gradual rise of VDD voltage (power supply voltage) within the linear region, thereby further suppressing inrush current and improving the stability of circuit startup. Specifically, when the potentials of the source terminals S of the first switch Q1 and the second switch Q2 are higher than the gate terminals G of the first switch Q1 and the second switch Q2, the first switch Q1 and the second switch Q2 can gradually turn on as the potential of the source terminals S increases, and the power supply voltage will also gradually rise, making the rise edge of the power supply voltage gradual, thereby achieving the purpose of soft start.

[0071] In one embodiment, it can be as follows Figure 3 As shown, the first switching module 200 further includes a first resistor R1, which has a first terminal and a second terminal. The first terminal of the first resistor R1 is coupled to the control terminal of the first switching transistor Q1, and the first terminal of the first resistor R1 is also coupled to the control terminal of the second switching transistor Q2. The second terminal of the first resistor R1R2 is coupled to the input terminal of the first switching transistor Q1, and the second terminal of the first resistor R1R2 is also coupled to the input terminal of the second switching transistor Q2.

[0072] For example, the first end of the first resistor R1 is coupled to the gate terminal G of the first switch Q1, and the second end of the first resistor R1 is coupled to the source terminal S of the first switch Q1. This provides a charge discharge path, allowing residual charge to be released quickly and reducing the possibility of false turn-on due to charge accumulation. The first resistor R1 can also form a low-Q LRC network with the parasitic inductance and capacitance of the gate terminal G of the first switch Q1, thereby suppressing ringing and improving the stability of the startup control circuit.

[0073] In this embodiment, the first end of the first resistor R1 is coupled to the control terminal of the first switch Q1, and the first end of the first resistor R1 is also coupled to the control terminal of the second switch Q2. The second end of the first resistor R1R2 is coupled to the input terminal of the first switch Q1, and the second end of the first resistor R1R2 is also coupled to the input terminal of the second switch Q2. This helps to suppress the charge change at the gate G of the first switch Q1 and the second switch Q2 through the first resistor R1, which helps to reduce the influence of the Miller effect and improve the stability of the soft-start circuit. The Miller effect refers to the phenomenon that during the switching process of a field-effect transistor (MOSFET / IGBT), the capacitance between the gate G and the drain D of the MOSFET causes voltage fluctuations at the gate G due to the Miller effect, leading to oscillation or false triggering. Reducing the influence of the Miller effect helps to improve the stability of the circuit.

[0074] In one embodiment, it can be as follows Figure 3As shown, the first switching module 200 further includes a first capacitor C1, which has a first terminal and a second terminal. The first terminal of the first capacitor C1 is coupled to the output terminal of the first switching transistor Q1, and the second terminal of the first capacitor C1 is coupled to the input terminal of the second switching transistor Q1. The first terminal of the first capacitor C1 is also coupled to the output terminal of the second switching transistor Q2, and the second terminal of the first capacitor C1 is also coupled to the input terminal of the second switching transistor Q2.

[0075] For example, the first terminal of the first capacitor C1 is coupled to the output terminal of the first switching transistor Q1, and the second terminal of the first capacitor C1 is coupled to the input terminal of the second switching transistor Q1. The first terminal of the first capacitor C1 is also coupled to the output terminal of the second switching transistor Q2, and the second terminal of the first capacitor C1 is also coupled to the input terminal of the second switching transistor Q2, which can suppress voltage spikes when the circuit is turned off. If the first switching transistor Q1 is a MOSFET, the MOSFET has parasitic effects, and there is a parasitic capacitance between the drain terminal D and the source terminal S of the MOSFET, which will generate voltage spikes and oscillations in high-frequency switching scenarios. Connecting the first capacitor C1 between the drain terminal D and the source terminal S of the first switching transistor Q1 can provide a low-impedance path and absorb high-frequency noise in the circuit. On the other hand, the first capacitor C1 can form an LC filter with the circuit inductance to suppress high-frequency interference in the circuit, reduce coupling interference, and enhance the stability of the circuit. In addition, adding the first capacitor C1 can also increase the rise time of Vds, thereby buffering the switching speed and reducing turn-off losses.

[0076] For example, in this embodiment, the first capacitor C1 is used as an impedance device. The same effect can also be achieved by setting a resistor device at the position of the first capacitor C1. The effect is similar to that of the first capacitor C1, and will not be described in detail here.

[0077] In this embodiment, a first capacitor C1 is provided. The first end of the first capacitor C1 is coupled to the output terminal of the first switching transistor Q1, and the second end of the first capacitor C1 is coupled to the input terminal of the second switching transistor Q1. The first end of the first capacitor C1 is also coupled to the output terminal of the second switching transistor Q2, and the second end of the first capacitor C1 is also coupled to the input terminal of the second switching transistor Q2. This helps to absorb the negative effects of parasitic capacitance through the first capacitor C1, thereby improving frequency response, enhancing anti-interference capability, and strengthening circuit stability.

[0078] In one embodiment, it can be as follows Figure 3 As shown, a second resistor R2 is provided between the first switch module 200 and the second switch module 300. The second resistor R2 has a first end and a second end. The first end of the second resistor R2 is coupled to the control end of the first switch tube Q1 and the control end of the second switch tube Q2. The second end of the second resistor R2 is coupled to the first end of the second switch module 300.

[0079] For example, when the output impedance of the main control module 100 does not match the input impedance of the first switch module 200, there may be a negative effect of signal reflection. By setting a second resistor R2 between the first switch module 200 and the second switch module 300, impedance matching can be enhanced, ringing can be reduced, voltage overshoot can be prevented, voltage oscillation can be suppressed, and the stability of the startup control circuit can be enhanced.

[0080] In this embodiment, a second resistor R2 is connected between the first switch module 200 and the second switch module 300. The matching degree of the switch modules is enhanced by the second resistor R2, which helps to enhance the stability of the circuit.

[0081] In one embodiment, it can be as follows Figure 2 As shown, the start-up control circuit also includes a current detection module 400.

[0082] The current detection module 400 is coupled to the power supply circuit between the first switch module 200 and the powered load 500. The current detection module 400 is used to detect the current value on the power supply circuit. The main control module 100 is also connected to the current detection module 400 and receives the current value detected by the current detection module 400. The main control module 100 is used to compare the current value with a preset value stored internally, and is configured to output a shutdown signal when the current value is greater than the preset value. The shutdown signal is used to shut down the second switch module 300.

[0083] The internally stored preset values ​​can be current thresholds set by technicians to determine the power supply status. When the current value exceeds the preset value, it can indicate that there is an abnormality in the power supply.

[0084] For example, the current detection module 400 can be a functional module for acquiring and detecting loop current. The current detection module 400 has the functions of monitoring, abnormal feedback and signal isolation. Therefore, the current detection module 400 can be implemented based on the following optional solutions, such as a combination of sampling resistor and signal amplifier; Hall sensor; current transformer, etc.

[0085] In this embodiment, a current detection module 400 is set in the startup control circuit. The current detection module 400 provides feedback adjustment to the drive control of the main control module 100. When an abnormal scenario occurs, the power supply can be shut off, thereby further enhancing the stability and safety of the circuit startup control.

[0086] In one embodiment, it can be as follows Figure 3 As shown, the current detection module 400 includes a sampling resistor R3 and an operational amplifier.

[0087] The sampling resistor R3 is connected in series in the power supply circuit between the first switching module 200 and the powered load 500.

[0088] The operational amplifier has a first input terminal, a second input terminal, and an output terminal. The first input terminal of the operational amplifier is coupled to the first end of the sampling resistor R3, the second input terminal of the operational amplifier is coupled to the second end of the sampling resistor R3, and the output terminal of the operational amplifier is coupled to the main control module 100.

[0089] In one embodiment, an operational amplifier is connected across the sampling resistor R3 to amplify the voltage difference across the sampling resistor R3.

[0090] In a specific example, the operational amplifier can be implemented based on the current sensing amplifier U2. Exemplarily, the current sensing amplifier U2 can refer to an analog integrated circuit used for high-precision current measurement, which detects the small voltage drop across the sampling resistor R3, amplifies it, and outputs a voltage signal proportional to the current.

[0091] Furthermore, the operational amplifier may also include a filter capacitor C3 that works in conjunction with the current sensing amplifier U2, an output matching impedance, etc.

[0092] In this embodiment, the current detection module 400 includes a sampling resistor R3 and an operational amplifier. The operational amplifier helps to enhance the sensitivity of current detection and can also convert the current signal, which helps to improve the efficiency of feedback response in abnormal scenarios.

[0093] In one embodiment, it can be as follows Figure 3 As shown, the current detection module 400 also includes:

[0094] Filtering unit 410 is located between sampling resistor R3 and operational amplifier, and is used to filter the differential voltage signal acquired by operational amplifier. Filtering unit 410 includes:

[0095] The first filter resistor R6 has a first end and a second end. The first end of the first filter resistor R6 is coupled to the first end of the sampling resistor R3, and the second end of the first filter resistor R6 is coupled to the first input end of the operational amplifier.

[0096] The second filter resistor R7 has a first end and a second end. The first end of the second filter resistor R7 is coupled to the second end of the sampling resistor R3, and the second end of the second filter resistor R7 is coupled to the second input end of the operational amplifier.

[0097] The filter capacitor C3 has a first terminal and a second terminal. The first terminal of the filter capacitor C3 is coupled to the first terminal of the first filter resistor R6, and the second terminal of the filter capacitor C3 is coupled to the second terminal of the second filter resistor R7.

[0098] In implementation, the first filter resistor R6, the second filter resistor R7, and the filter capacitor C3 can form a π-type filter circuit. A π-type filter circuit is a passive filter circuit named for its topology resembling the Greek letter "π". It consists of two capacitors (input / output terminals) and one inductor (or resistor), primarily used for power supply noise suppression, signal filtering, and high-frequency interference removal. This embodiment uses the above filter circuit as an example; other filter modules have similar effects and will not be elaborated upon.

[0099] In one of the most specific exemplary embodiments, a start-up control circuit is provided as follows: Figure 3 As shown, during implementation, when the external power supply VIN+ is connected, the MCU-IO pin of the main control module is controlled by the program to output a low level. At this time, the third switch Q3 is not conducting, so the first switch Q1 and the second switch Q2 are also not conducting, and VIN+ is not applied to the VDD pin of the chip. When the MCU-IO pin of the main control module is controlled by the program to output a high level, the third switch Q3 starts to conduct, and the first switch Q1 and the second switch Q2 also start to conduct. VIN+ is gradually applied to the VDD pin of the chip. Because of the circuit composed of the first switch Q1 and the second switch Q2, the input voltage spike can be suppressed, so there will be no instantaneous voltage spike entering the VDD pin of the chip. Because the first switch Q1 and the second switch Q2 are turned on, the surge voltage during power-on can be effectively limited.

[0100] In this embodiment, according to the working principle of the P-channel MOSFET, the source potential (S) of the first switch Q1 and the second switch Q2 is higher than the gate potential (G). As the source potential (S) increases, the first switch Q1 and the second switch Q2 will gradually turn on, and the power supply voltage will gradually increase. The rising edge will be relatively flat, thereby realizing the soft-start function.

[0101] Furthermore, when the first switch Q1 and the second switch Q2 are turned on, the current loaded at VIN+ will enter the VDD pin of the chip through the sampling resistor R3. At this time, the output of the operational amplifier U2 is connected to the ADC sampling port MCU-IO-ADC of the main control module. By acquiring the voltage value across the sampling resistor R3, the main control module can obtain the current value in this path in real time through the MCU-IO-ADC port. If an abnormally large current occurs in this path, the microcontroller will quickly detect the abnormality and turn off the third switch Q3 through MCU-IO, thereby turning off the first switch Q1 and the second switch Q2, terminating the voltage and current input at VIN+. Through the feedback circuit composed of the main control module, the operational amplifier U2, and peripheral components, the circuit protection function can be effectively realized in real time.

[0102] Based on the same inventive concept, this application also provides an electronic device, including a start-up control circuit according to any one of the above embodiments.

[0103] It is understood that the above-mentioned start-up control circuit can also take other forms, and is not limited to the forms mentioned in the above embodiments, as long as it can achieve the function of enhancing the stability of start-up power supply control.

[0104] In the description of this specification, references to terms such as "some embodiments," "other embodiments," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative descriptions of the above terms do not necessarily refer to the same embodiments or examples.

[0105] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0106] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these modifications and improvements all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A start-up control circuit, characterized in that, include: A first switch module has a first terminal, a second terminal and a control terminal. The first terminal of the first switch module is coupled to a power supply, and the second terminal of the first switch module is coupled to a power supply terminal between the powered load. The second switch module has a first terminal, a second terminal and a control terminal. The first terminal of the second switch module is coupled to the control terminal of the first switch module, and the second terminal of the second switch module is coupled to a reference ground. The main control module is connected to the control terminal of the power supply and the second switch module. The main control module is configured to output a start control signal after a delay in response to the power supply being turned on, wherein the start control signal is used to turn on the second switch module.

2. The start-up control circuit according to claim 1, characterized in that, The first switching module includes a first switching transistor and a second switching transistor. Both the first switching transistor and the second switching transistor include an input terminal, an output terminal and a control terminal. The input terminal of the first switching transistor is coupled to the input terminal of the second switching transistor, the output terminal of the first switching transistor is coupled to the output terminal of the second switching transistor, and the control terminal of the first switching transistor is coupled to the control terminal of the second switching transistor. The control terminal of the first switch is also coupled to the input terminal of the first switch, and the control terminal of the second switch is also coupled to the input terminal of the second switch.

3. The start-up control circuit according to claim 2, characterized in that, The second switching module includes a third switching transistor, which includes an input terminal, an output terminal, and a control terminal. The control terminals of the first and second switching transistors are both coupled to the output terminal of the third switching transistor. The input terminals of the first and second switching transistors are both coupled to the output terminal of the power supply. The output terminals of the first and second switching transistors are both coupled to the input terminal of the powered load. The control terminal of the third switch is coupled to the main control module, and the input terminal of the third switch is coupled to reference ground.

4. The start-up control circuit according to claim 3, characterized in that, The first switching module further includes a first resistor, which has a first end and a second end. The first end of the first resistor is coupled to the control end of the first switching transistor and the control end of the second switching transistor, and the second end of the first resistor is coupled to the input end of the first switching transistor and the input end of the second switching transistor.

5. The start-up control circuit according to claim 3, characterized in that, The first switching module further includes a first capacitor, which has a first terminal and a second terminal. The first terminal of the first capacitor is coupled to the output terminal of the first switching transistor and the output terminal of the second switching transistor, and the second terminal of the first capacitor is coupled to the input terminal of the first switching transistor and the input terminal of the second switching transistor.

6. The start-up control circuit according to claim 3, characterized in that, A second resistor is provided between the first switch module and the second switch module. The second resistor has a first end and a second end. The first end of the second resistor is coupled to the control end of both the first switch and the second switch. The second end of the second resistor is coupled to the output end of the third switch.

7. The start-up control circuit according to any one of claims 1 to 6, characterized in that, The start-up control circuit also includes: A current detection module is coupled to the power supply circuit between the first switch module and the powered load, and the current detection module is used to detect the current value on the power supply circuit. The main control module is also connected to the current detection module and receives the current value detected by the current detection module. The main control module is used to compare the current value with a preset value and is configured to output a shutdown signal when the current value is greater than the preset value. The shutdown signal is used to shut down the second switch module.

8. The start-up control circuit according to claim 7, characterized in that, The current detection module includes: A sampling resistor is connected in series in the power supply circuit between the first switching module and the powered load; An operational amplifier has a first input terminal, a second input terminal, and an output terminal. The first input terminal of the operational amplifier is coupled to the first terminal of the sampling resistor, the second input terminal of the operational amplifier is coupled to the second terminal of the sampling resistor, and the output terminal of the operational amplifier is coupled to the main control module.

9. The start-up control circuit according to claim 8, characterized in that, The current detection module also includes: A filtering unit, disposed between the sampling resistor and the operational amplifier, is used to filter the differential voltage signal acquired by the operational amplifier. The filtering unit includes: A first filter resistor has a first terminal and a second terminal. The first terminal of the first filter resistor is coupled to the first terminal of the sampling resistor, and the second terminal of the first filter resistor is coupled to the first input terminal of the operational amplifier. The second filter resistor has a first terminal and a second terminal. The first terminal of the second filter resistor is coupled to the second terminal of the sampling resistor, and the second terminal of the second filter resistor is coupled to the second input terminal of the operational amplifier. A filter capacitor has a first terminal and a second terminal. The first terminal of the filter capacitor is coupled to the first terminal of the first filter resistor, and the second terminal of the filter capacitor is coupled to the second terminal of the second filter resistor.

10. An electronic device, characterized in that, Includes the start-up control circuit according to any one of claims 1-9.

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