Gradual start-up circuit and wireless charging circuit

Abstract

This disclosure relates to a soft-start circuit and a wireless charging circuit. The soft-start circuit has a switch with a first terminal, a second terminal, and a control terminal. A first power supply unit outputs voltage and current to a power-consuming unit, and the first and second terminals of the switch are connected in series in the power supply circuit containing the first power supply unit and the power-consuming unit. The soft-start circuit may further include a first diode and a delay circuit. The anode of the first diode is coupled to the control terminal of the switch. The input terminal of the delay circuit receives a second control voltage, and the output terminal of the delay circuit is coupled to a reference ground. The control terminal of the delay circuit is coupled to the cathode of the first diode. When the first control voltage supplies power to the switch and the second control voltage supplies power to the delay circuit, the first diode conducts. The potential of the control terminal of the switch is positively correlated with the potential of the control terminal of the delay circuit. The delay circuit can delay the rise of the potential of its control terminal, thereby delaying the conduction of the switch and realizing the soft start of the first power supply unit supplying power to the power-consuming unit.

Description

Technical Field

[0001] This disclosure relates to the field of startup circuit technology, and more particularly to a soft-start circuit and a wireless charging circuit. Background Technology

[0002] In related wireless charging technologies, electrical energy is transmitted between the transmitting and receiving ends via coils. At the receiving end, a WPIC (Wireless Charging Integrated Circuit, also known as a wireless charging chip) converts the electrical energy into current and voltage to supply the power-consuming unit, thus achieving the wireless charging function. However, in these technologies, the WPIC is directly connected to the power-consuming unit, and voltage / current anomalies can easily affect the unit, leaving it unable to react in time. For example, a sudden surge in current can damage the components of the power-consuming unit. Although some technologies use software soft-start, software bugs (defects, problems) can also cause soft-start anomalies.

[0003] In summary, there are still some technical problems that need to be solved in terms of protecting the power-consuming unit in current wireless charging technology. Utility Model Content

[0004] This disclosure provides a soft-start circuit and a wireless charging circuit that can improve the safety of wireless charging.

[0005] This disclosure provides a soft-start circuit, including:

[0006] A switch has a first terminal, a second terminal, and a control terminal. The switch is connected in series with its first and second terminals in a power supply circuit containing a first power supply unit and a power consumption unit. The control terminal of the switch receives a first control voltage, which is used to control the switch to be turned on or off. The first power supply unit is used to output voltage and current to the power consumption unit.

[0007] The first diode has its anode coupled to the control terminal of the switch;

[0008] A delay circuit has an input terminal, an output terminal, and a control terminal. The input terminal of the delay circuit receives a second control voltage, the output terminal of the delay circuit is coupled to a reference ground, and the control terminal of the delay circuit is coupled to the cathode of the first diode.

[0009] When the first control voltage supplies power to the switch and the second control voltage supplies power to the delay circuit, the first diode is turned on, and the potential of the control terminal of the switch is positively correlated with the potential of the control terminal of the delay circuit.

[0010] In one possible implementation, the delay circuit includes a first resistor, a second resistor, and an energy storage capacitor;

[0011] Wherein, the first end of the first resistor is coupled to the first end of the energy storage capacitor, the second end of the first resistor is coupled to the second end of the energy storage capacitor, the second end of the energy storage capacitor is coupled to the output terminal of the delay circuit, the first end of the second resistor is coupled to the first power supply unit, and the second end of the second resistor is coupled to the first end of the energy storage capacitor.

[0012] In one possible implementation, the soft-start circuit includes a second diode, the anode of which is coupled to a first terminal of the switch, and the cathode of which is coupled to a control terminal of the switch.

[0013] In one possible implementation, the voltage drop across the first resistor during the discharge of the energy storage capacitor is greater than the voltage regulation value of the second diode.

[0014] In one possible implementation, the soft-start circuit further includes a third resistor and a fourth resistor, the first end of the third resistor being coupled to the control terminal of the switch, the second end of the third resistor being coupled to the first end of the fourth resistor, and the second end of the fourth resistor being coupled to the second terminal of the switch.

[0015] In one possible implementation, the soft-start circuit includes a fifth resistor, a first end of which is coupled to the first power supply unit, and a second end of which is coupled to the control terminal of the switch.

[0016] In one possible implementation, the soft-start circuit includes a fifth resistor and a second power supply unit, the second power supply unit outputting the first control voltage, a first end of the fifth resistor being coupled to the second power supply unit, and a second end of the fifth resistor being coupled to the control terminal of the switch.

[0017] In one possible implementation, the delay circuit includes a first resistor, a second resistor, an energy storage capacitor, and a third power supply unit, wherein the third power supply unit outputs the second control voltage;

[0018] Wherein, the first end of the first resistor is electrically connected to the first end of the energy storage capacitor, the second end of the first resistor is coupled to the second end of the energy storage capacitor, the second end of the energy storage capacitor is coupled to the output terminal of the delay circuit, the first end of the second resistor is coupled to the third power supply unit, and the second end of the second resistor is coupled to the first end of the energy storage capacitor.

[0019] In one possible implementation, the first control voltage is the same as the second control voltage.

[0020] This disclosure also provides a wireless charging circuit, which includes a first power supply unit, a power consumption unit, and a soft-start circuit as described in any of the first aspects. The first power supply unit includes a power supply terminal and a first ground terminal, and the power consumption unit includes a receiving terminal and a second ground terminal.

[0021] The switch of the soft-start circuit is connected in series between the power supply terminal and the receiving terminal through the first and second terminals of the switch, or the switch of the soft-start circuit is connected in series between the first ground terminal and the second ground terminal through the first and second terminals of the switch.

[0022] According to the soft-start circuit and wireless charging circuit provided in the embodiments of this disclosure, the switch of the soft-start circuit has a first terminal, a second terminal, and a control terminal. A first power supply unit is used to output voltage and current to a power-consuming unit. The first terminal and the second terminal of the switch are connected in series in the power supply circuit where the first power supply unit and the power-consuming unit are located, so as to realize the control of the first power supply unit to supply power to the power-consuming unit. The soft-start circuit may further include a first diode and a delay circuit. The anode of the first diode is coupled to the control terminal of the switch. The input terminal of the delay circuit receives a second control voltage. The output terminal of the delay circuit is coupled to a reference ground. The control terminal of the delay circuit is coupled to the cathode of the first diode. When the first control voltage supplies power to the switch and the second control voltage supplies power to the delay circuit, the first diode conducts. The potential of the control terminal of the switch is positively correlated with the potential of the control terminal of the delay circuit. The delay circuit can delay the rise of the potential of its control terminal, thereby delaying the rise of the potential of the control terminal of the switch, thereby delaying the conduction of the switch, and realizing the soft start of the first power supply unit supplying power to the power-consuming unit. In other words, this disclosure can effectively delay the conduction of the switches in the power supply circuit where the first power supply unit and the power consumption unit are located, so that the conduction of voltage and current from the first power supply unit to the power consumption unit is delayed, reducing the impact of inrush current on the power consumption unit, avoiding damage to the components of the power consumption unit due to instantaneous large current, and thus ensuring the stability and safety of the circuit. Attached Figure Description

[0023] The accompanying drawings, incorporated in and forming part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure. To more clearly illustrate the technical solutions in the embodiments of this disclosure or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, those skilled in the art can obtain other drawings based on these drawings without creative effort. One or more embodiments are illustrated by way of example through the corresponding images in the accompanying drawings. These exemplary descriptions do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings represent similar elements. Unless otherwise stated, the figures in the drawings do not constitute a limitation on scale.

[0024] Figure 1 A circuit diagram of a soft-start circuit provided in an embodiment of this disclosure;

[0025] Figure 2 A circuit diagram of another soft-start circuit provided in an embodiment of this disclosure;

[0026] Figure 3 A circuit diagram of another soft-start circuit provided in an embodiment of this disclosure;

[0027] Figure 4 A circuit diagram of another soft-start circuit provided in an embodiment of this disclosure;

[0028] Figure 5 A circuit diagram of another soft-start circuit provided in an embodiment of this disclosure;

[0029] Figure 6 A circuit diagram of another soft-start circuit provided in an embodiment of this disclosure;

[0030] Figure 7 This is a circuit diagram of another wireless charging circuit provided in an embodiment of the present disclosure.

[0031] Explanation of reference numerals in the attached figures:

[0032] 100. First power supply unit; 200. Soft start circuit; 210. Delay circuit; 300. Power consumption unit; 400. Second power supply unit; 500. Third power supply unit;

[0033] Q1, switch; C1, energy storage capacitor; R1, first resistor; R2, second resistor; R3, third resistor; R4, fourth resistor; R5, fifth resistor; D1, first diode; D2, second diode;

[0034] TX, Transmitter; RX, Receiver; TX Control, Wireless Charging Pad Control System; TX Coil, Wireless Charging Pad Coil; RX Coil, Receiver Coil; WP IC, Wireless Charging Chip. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this disclosure. Based on the embodiments of this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.

[0036] The following disclosure provides numerous different embodiments or examples for implementing various structures of this disclosure. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the scope of this disclosure. Furthermore, reference numerals and / or letters may be repeated in different examples. Such repetition is for simplicity and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, various specific examples of processes and materials are provided in this disclosure; however, those skilled in the art will recognize the applicability of other processes and / or the use of other materials.

[0037] For ease of description, spatial relative terms may be used in the text to describe the relative position or movement of one element or feature relative to another element or feature, as shown in the figure. These relative terms include, for example, "inside," "outside," "middle," "outer," "below," "below," "above," "front," "back," etc. Such spatial relative terms are intended to include different orientations of the device in use or operation, other than those depicted in the figure. For example, if the device in the figure undergoes a positional flip, orientation change, or change of motion, these directional indications will change accordingly. For instance, an element described as "below other elements or features" or "below other elements or features" will subsequently be oriented "above other elements or features" or "above other elements or features." Therefore, the example term "below" can include both upper and lower orientations. The device may be otherwise oriented (rotated 90 degrees or in other directions), and the spatial relative descriptors used in the text will be interpreted accordingly.

[0038] In some exemplary embodiments, reference is made to Figure 1 As shown, a soft-start circuit 200 is provided. The soft-start circuit 200 may include a switch Q1, a first diode D1, and a delay circuit 210.

[0039] The switch Q1 has a first terminal, a second terminal, and a control terminal. The control terminal is used to control the switching Q1 to be turned on and off. The switch Q1 is connected in series with its first and second terminals in the power supply circuit where the first power supply unit 100 and the power consumption unit 300 are located. The control terminal of the switch Q1 receives a first control voltage, which is used to control the switching Q1 to be turned on or off, thereby controlling whether the first power supply unit 100 outputs voltage and current to the power consumption unit 300.

[0040] It should be noted that switch Q1 can be a MOSFET or other types of switches, and there is no limitation thereto. In one embodiment, switch Q1 is an N-channel MOSFET, where the gate of the MOSFET can be used as the control terminal of switch Q1, the source of the MOSFET can be used as the first terminal of switch Q1, and the drain of the MOSFET can be used as the second terminal of switch Q1. In another embodiment, the MOSFET is a P-channel MOSFET, where the gate of the MOSFET can be used as the control terminal of switch Q1, the drain of the MOSFET can be used as the second terminal of switch Q1, and the source of the MOSFET can be used as the first terminal of switch Q1.

[0041] The delay circuit 210 has an input terminal, an output terminal, and a control terminal. The control terminal is used to control the voltage of the cathode of the first diode D1. The input terminal of the delay circuit 210 is used to receive a second control voltage. The output terminal of the delay circuit 210 is coupled to a reference ground. The control terminal of the delay circuit 210 is coupled to the cathode of the first diode D1, and the anode of the first diode D1 is coupled to the control terminal of the switch Q1.

[0042] Wherein, the first control voltage is used to control the switching Q1 to be turned on or off. When the second control voltage supplies power to the delay circuit 210, the potential of the cathode of the first diode D1 is the potential of the control terminal of the delay circuit 210, and the potential of the anode of the first diode D1 is the potential of the control terminal of the switch Q1 (i.e., the first control voltage), thereby creating a voltage difference between the cathode and anode of the first diode D1, which in turn causes the first diode D1 to be turned on. The potential of the control terminal of the switch Q1 is positively correlated with the potential of the control terminal of the delay circuit 210, that is, the larger the potential of the control terminal of the delay circuit 210, the larger the potential of the control terminal of the switch Q1.

[0043] It should be noted that the delay of the delay circuit 210 refers to slowing down the rate of potential rise at the control terminal of the delay circuit 210. Therefore, the potential rise at the control terminal of the delay circuit 210 is slow, and thus, under the action of the first diode D1, the potential at the control terminal of the switch Q1 will also rise slowly, thereby realizing the slow conduction of the switch Q1 and achieving a soft start.

[0044] In other words, when the first control voltage supplies power to switch Q1 and the second control voltage supplies power to delay circuit 210, a voltage difference is formed between the cathode and anode of the first diode D1, which makes the first diode D1 conduct. Therefore, when the first power supply unit 100 needs to supply power to the power consumption unit 300, the first diode D1 in the soft start circuit 200 is in the conducting state. The current originally supplied by the first power supply unit 100 to the control terminal of switch Q1 can be absorbed by the control terminal of delay circuit 210 through the first diode D1. In this state, the first power supply unit 100 can be limited to supply power to the control terminal of switch Q1. Since the delay circuit 210 can delay the rise of the cathode potential of the first diode D1, when the conduction voltage drop of the first diode D1 is stable, the potential of the anode of the first diode D1, that is, the control terminal of switch Q1, also rises slowly, thereby delaying the conduction of switch Q1. As the control terminal of the delay circuit 210 is powered on, its potential gradually increases, and the potential of the control terminal of switch Q1 also gradually increases until the potential of the control terminal of switch Q1 is sufficient to turn on switch Q1. After the switch Q1 circuit is turned on, the first power supply unit 100 can supply power to the power consumption unit 300 through switch Q1.

[0045] This embodiment can effectively slow down the voltage rise rate at the control terminal of switch Q1 in the power supply circuit where the first power supply unit 100 and the power consumption unit 300 are located, thereby delaying the conduction time of switch Q1. This delays the conduction of voltage and current from the first power supply unit 100 to the power consumption unit 300, reduces the impact of inrush current on the power consumption unit 300, and avoids damage to components of the power consumption unit 300 due to instantaneous large current, thereby ensuring the stability and safety of the circuit.

[0046] In some embodiments, the first power supply unit 100 may include a power supply terminal and a first ground terminal, and the power consumption unit 300 may include a receiving terminal and a second ground terminal. The switch Q1 of the soft-start circuit 200 can be connected in series between the power supply terminal and the receiving terminal via its first and second terminals.

[0047] In other embodiments, the first power supply unit 100 may include a power supply terminal and a first ground terminal, the power consumption unit 300 may include a receiving terminal and a second ground terminal, and the switch Q1 of the soft start circuit 200 is connected in series between the first ground terminal and the second ground terminal through the first terminal and the second terminal of the switch Q1.

[0048] It should be noted that the model of switch Q1 in the different embodiments described above may be different. Moreover, regardless of which implementation method is adopted, this embodiment can effectively delay the conduction of switch Q1 in the power supply circuit where the first power supply unit 100 and the power consumption unit 300 are located. This delays the conduction of voltage and current from the first power supply unit 100 to the power consumption unit 300, reduces the impact of inrush current on the power consumption unit 300, and avoids damage to the components of the power consumption unit 300 due to instantaneous large current, thereby ensuring the stability and safety of the circuit.

[0049] In some exemplary embodiments, reference is made to Figure 2 As shown, a soft-start circuit 200 is provided. In this embodiment, the delay circuit 210 in the soft-start circuit 200 includes a first resistor R1, a second resistor R2, and an energy storage capacitor C1. The first end of the first resistor R1 is coupled to the first end of the energy storage capacitor C1, and the second end of the first resistor R1 is coupled to the second end of the energy storage capacitor C1. The second end of the energy storage capacitor C1 is coupled to the output terminal of the delay circuit 210. The second end of the second resistor R2 is coupled to the first end of the energy storage capacitor C1. The first end of the energy storage capacitor C1 can be used as the control terminal of the delay circuit 210 and coupled to the cathode of the first diode D1. The first end of the second resistor R2 can be used as the input terminal of the delay circuit 210 to receive a second control voltage.

[0050] In this embodiment, the first end of the second resistor R2 can be coupled to the power supply terminal of the first power supply unit 100. That is, the first power supply unit 100 can provide a second control voltage to the input terminal of the delay circuit 210. Based on this, when the first power supply unit 100 needs to supply power to the power consumption unit 300, the first diode D1 in the soft start circuit 200 is in the conducting state. The voltage originally provided by the first control voltage to the control terminal of switch Q1 is absorbed by the first diode D1 and the current is absorbed to the first end of the energy storage capacitor C1 of the delay circuit 210, thereby charging the energy storage capacitor C1. In this state, the first control voltage can be limited to supply power to the control terminal of switch Q1, thereby delaying the conduction of switch Q1. As the first control voltage and the second control voltage output by the first power supply unit 100 charge the energy storage capacitor C1, the potential of the first terminal of the energy storage capacitor C1 (i.e., the control terminal of the delay circuit 210) gradually increases, and the potential at the control terminal of the switch Q1 also gradually increases. When the energy storage capacitor C1 is fully charged, the potential of the first terminal of the energy storage capacitor C1 (i.e., the control terminal of the delay circuit 210) reaches its maximum, and the potential at the control terminal of the switch Q1 is sufficient to control the switch Q1 to conduct. After the switch Q1 is turned on, the first power supply unit 100 can supply power to the power consumption unit 300 through the switch Q1. At the same time, the energy storage capacitor C1 can discharge through the discharge circuit formed by the energy storage capacitor C1 and the first resistor R1. At this time, the first diode D1 is in the open state, thereby disconnecting the discharge circuit of the energy storage capacitor C1 from the control terminal of the switch Q1, which can prevent the discharge of the energy storage capacitor C1 from affecting the control terminal of the switch Q1.

[0051] It should be noted that the second control voltage can be provided by the first power supply unit 100 or other power supply units, and there is no limitation on this.

[0052] In some implementations, reference Figure 3 and Figure 4As shown, a soft-start circuit 200 is provided. In this embodiment, the delay circuit 210 in the soft-start circuit 200 includes a first resistor R1, a second resistor R2, an energy storage capacitor C1, and a third power supply unit 500, which outputs the second control voltage. The first end of the first resistor R1 is electrically coupled to the first end of the energy storage capacitor C1, and the second end of the first resistor R1 is coupled to the second end of the energy storage capacitor C1. The second end of the energy storage capacitor C1 is coupled to the output terminal of the delay circuit 210. The first end of the second resistor R2 is coupled to the third power supply unit 500, and the second end of the second resistor R2 is coupled to the first end of the energy storage capacitor C1. In other words, in this embodiment, the third power supply unit 500 provides the second control voltage to the control terminal of the delay circuit 210. Based on this, when the first power supply unit 100 needs to supply power to the power consumption unit 300, the first diode D1 in the soft-start circuit 200 is in a conducting state. The voltage originally provided by the control terminal of the first control voltage switch Q1 can be transmitted to the first terminal of the energy storage capacitor C1 in the delay circuit 210 through the first diode D1, thereby charging the energy storage capacitor C1. In this state, the power supply to the control terminal of the first control voltage switch Q1 can be limited, thereby delaying the conduction of the switch Q1. As the first control voltage and the second control voltage output by the third power supply unit 500 charge the energy storage capacitor C1, the potential of the first terminal of the energy storage capacitor C1 (i.e., the control terminal of the delay circuit 210) gradually increases, and the potential of the control terminal of the switch Q1 also gradually increases. When the energy storage capacitor C1 is fully charged, the potential of the first terminal of the energy storage capacitor C1 (i.e., the control terminal of the delay circuit 210) reaches its maximum, and the potential of the control terminal of the switch Q1 is sufficient to control the switch Q1 to conduct. After the switch Q1 is turned on, the first power supply unit 100 can supply power to the power consumption unit 300 through the switch Q1. At the same time, the energy storage capacitor C1 can be discharged through the discharge circuit formed by the energy storage capacitor C1 and the first resistor R1. At this time, the first diode D1 is in the open state, thereby disconnecting the discharge circuit of the energy storage capacitor C1 from the control terminal of the switch Q1, which can prevent the discharge of the energy storage capacitor C1 from affecting the control terminal of the switch Q1.

[0053] In addition, in this embodiment, the soft-start circuit 200 may also include a second diode D2, the anode of the second diode D2 being coupled to the first terminal of the switch Q1, and the cathode of the second diode D2 being coupled to the control terminal of the switch Q1. The function of the second diode D2 is to protect the switch Q1 from being broken down by high voltage.

[0054] When the soft-start circuit 200 is equipped with the aforementioned second diode D2, the voltage division value of the first resistor R1 when the energy storage capacitor C1 is discharged is greater than the voltage regulation value of the second diode D2. This causes the second diode D2 to clamp the voltage between the control terminal and the first terminal of the switch Q1 within a certain range, so as to better prevent the switch Q1 from being damaged by high voltage breakdown.

[0055] This embodiment effectively protects switch Q1 by setting a second diode D2, thereby ensuring the reliability and stability of the entire soft-start circuit 200, and consequently ensuring the reliability and stability of the wireless charging circuit.

[0056] In some exemplary embodiments, reference is made to Figure 2 and Figure 4 As shown, a soft-start circuit 200 is provided. In this embodiment, the soft-start circuit 200 further includes a third resistor R3 and a fourth resistor R4. The first end of the third resistor R3 is coupled to the control terminal of the switch Q1, the second end of the third resistor R3 is coupled to the first end of the fourth resistor R4, and the second end of the fourth resistor R4 is coupled to the second terminal of the switch Q1.

[0057] Since parasitic parameters in a MOSFET can easily cause self-oscillation, this embodiment connects two resistors in series between the gate and drain of the MOSFET, namely the third resistor R3 and the fourth resistor R4 mentioned above, which can effectively prevent self-oscillation of the MOSFET.

[0058] In addition, the soft-start circuit 200 may also include a fifth resistor R5. The first end of the fifth resistor R5 is coupled to the first power supply unit 100, and the second end of the fifth resistor R5 is coupled to the control terminal of the switch Q1. In this embodiment, since the fifth resistor R5 is provided between the control terminal of the switch Q1 and the first power supply unit 100, when the first power supply unit 100 provides a first control voltage to the control terminal of the switch Q1, the presence of the fifth resistor R5 can effectively control the rising slope of the current in the first power supply unit 100 and the control terminal of the switch Q1. This can better delay the rise in potential at the control terminal of the switch Q1, thereby better delaying the conduction of the switch Q1, further improving the soft-start effect of the soft-start circuit 200. This allows the voltage and current of the first power supply unit 100 to be better conducted to the power-consuming unit 300 after a delay, better reducing the impact of the inrush current on the power-consuming unit 300, and better avoiding damage to the components of the power-consuming unit 300 due to a sudden large current, thus better ensuring the stability and safety of the circuit.

[0059] It should be noted that the first control voltage can be provided by the first power supply unit 100 or by other power supply units, and there is no limitation on this.

[0060] For example, refer to Figure 5 and Figure 6 As shown, the soft-start circuit 200 includes a fifth resistor R5 and a second power supply unit 400. The second power supply unit 400 outputs the first control voltage. The first end of the fifth resistor R5 is coupled to the second power supply unit 400, and the second end of the fifth resistor R5 is coupled to the control terminal of the switch Q1. Because the fifth resistor R5 is provided between the control terminal of the switch Q1 and the second power supply unit 400, when the second power supply unit 400 provides the first control voltage to the control terminal of the switch Q1, the presence of the fifth resistor R5 can effectively control the current rise slope between the second power supply unit 400 and the control terminal of the switch Q1. This better delays the potential rise at the control terminal of the switch Q1, thus better delaying the conduction of the switch Q1, further improving the soft-start effect of the soft-start circuit 200. This allows for better delay in the conduction of voltage and current from the first power supply unit 100 to the power-consuming unit 300, better reducing the impact of inrush current on the power-consuming unit 300, and better preventing damage to the components of the power-consuming unit 300 due to instantaneous large current, thereby better ensuring the stability and safety of the circuit.

[0061] In some exemplary embodiments, reference is made to Figure 2 As shown, a soft-start circuit 200 is provided. In this embodiment, the switch Q1 is described as an N-channel MOSFET. The first control voltage and the second control voltage in this embodiment are the same and can both be provided by the first power supply unit 100. The soft-start circuit 200 may also include a fifth resistor R5, and the delay circuit 210 may include a first resistor R1, a second resistor R2, and an energy storage capacitor C1.

[0062] In this circuit, the first end of the first resistor R1 is coupled to the first end of the energy storage capacitor C1, and the second end of the first resistor R1 is coupled to the second end of the energy storage capacitor C1. The second end of the energy storage capacitor C1 is coupled to the output terminal of the delay circuit 210. The second end of the second resistor R2 is coupled to the first end of the energy storage capacitor C1. The first end of the energy storage capacitor C1 can serve as the control terminal of the delay circuit 210, coupled to the cathode of the first diode D1. The first end of the second resistor R2 can serve as the input terminal of the delay circuit 210, receiving a second control voltage. The first end of the first resistor R1 can be coupled to the power supply terminal of the first power supply unit 100, meaning that the first power supply unit 100 can provide a second control voltage to the input terminal of the delay circuit 210.

[0063] In this embodiment, the first end of the fifth resistor R5 is coupled to the first power supply unit 100, and the second end of the fifth resistor R5 is coupled to the control terminal of the switch Q1. Because the fifth resistor R5 is provided between the control terminal of the switch Q1 and the first power supply unit 100, the first power supply unit 100 provides the first control voltage to the control terminal of the switch Q1.

[0064] In other words, in this embodiment, the first control voltage and the second control voltage can be the same.

[0065] In this embodiment, when the first power supply unit 100 needs to supply power to the power consumption unit 300, the first diode D1 in the soft start circuit 200 is in the conducting state. The first control voltage originally provided by the first power supply unit 100 to the control terminal of the switch Q1 can be transmitted to the first terminal of the energy storage capacitor C1 of the delay circuit 210 through the first diode D1, thereby charging the energy storage capacitor C1. In this state, the first power supply unit 100 can be restricted from supplying power to the control terminal of the switch Q1, thereby delaying the conduction of the switch Q1.

[0066] As the first power supply unit 100 charges the energy storage capacitor C1, the potential of the first terminal of the energy storage capacitor C1 (i.e., the control terminal of the delay circuit 210) gradually increases, and the potential of the control terminal of the switch Q1 also gradually increases. When the energy storage capacitor C1 is fully charged, the potential of the first terminal of the energy storage capacitor C1 (i.e., the control terminal of the delay circuit 210) reaches its maximum, and the potential of the control terminal of the switch Q1 is sufficient to control the switch Q1 to conduct. After the switch Q1 is conducted, the first power supply unit 100 can supply power to the power consumption unit 300 through the switch Q1. At the same time, the energy storage capacitor C1 can discharge through the discharge circuit formed by the energy storage capacitor C1 and the first resistor R1. At this time, the first diode D1 is in the open state, thereby disconnecting the discharge circuit of the energy storage capacitor C1 from the control terminal of the switch Q1, which can prevent the discharge of the energy storage capacitor C1 from affecting the control terminal of the switch Q1.

[0067] Furthermore, when the first power supply unit 100 provides the first control voltage to the control terminal of switch Q1, the presence of the fifth resistor R5 can effectively control the rising slope of the current in the first power supply unit 100 and the control terminal of switch Q1. This can better delay the potential rise of the control terminal of switch Q1, thereby better delaying the conduction of switch Q1 and further improving the slow start effect of the slow start circuit 200. This allows the voltage and current of the first power supply unit 100 to be better conducted to the power consumption unit 300 after a delay, better reducing the impact of the inrush current on the power consumption unit 300. This can better prevent damage to the components of the power consumption unit 300 caused by instantaneous large current, thereby better ensuring the stability and safety of the circuit.

[0068] This embodiment, through the cooperation of devices such as delay circuit 210, switch Q1, first diode D1 and fifth resistor R5, can effectively delay the conduction of switch Q1, so that the voltage / current of the first power supply unit 100 is delayed in its transmission to the power consumption unit 300, reducing the impact of inrush current on the power consumption unit 300, avoiding damage to the components of the power consumption unit 300 due to instantaneous large current, and thus ensuring the stability and safety of the circuit.

[0069] In some exemplary embodiments, reference is made to Figure 7 As shown, a wireless charging circuit is provided. The wireless charging circuit includes a transmitter TX and a receiver RX. The transmitter TX may include a wireless charging pad control system TX Control and a wireless charging pad coil TX Coil. The receiver RX may include a receiver coil RX Coil, a wireless charging chip WP IC, and a power-consuming unit 300. The power-consuming unit 300 may include a battery and other power-consuming circuits or devices, etc., which are not limited thereto.

[0070] The wireless charging pad coil (TX) and the receiver coil (RX) are powered by alternating current of a certain frequency. Electromagnetic induction transfers energy from the transmitter (TX) to the receiver (RX). The energy transferred to the receiver (RX) is converted into corresponding voltage and current by the wireless charging chip (WP IC) to power the downstream power-consuming unit 300 (including charging the battery).

[0071] In this embodiment, a soft-start circuit 200 is provided between the wireless charging chip WP IC and the power-consuming unit 300. That is, the wireless charging IC chip can serve as the first power supply unit 100. By providing the soft-start circuit 200, this embodiment can effectively delay the conduction of switch Q1 in the power supply circuit containing the first power supply unit 100 and the power-consuming unit 300, so that the conduction of voltage and current from the first power supply unit 100 to the power-consuming unit 300 is delayed, reducing the impact of inrush current on the power-consuming unit 300, and avoiding damage to the components of the power-consuming unit 300 due to instantaneous large current, thereby ensuring the stability and safety of the circuit.

[0072] It should be understood that the terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “described” as used herein may also include the plural forms. The terms “comprising,” “including,” “containing,” and “having” are inclusive and therefore indicate the presence of the stated features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein are not construed as requiring them to be performed in a specific order described or illustrated unless the order of performance is explicitly indicated. It should also be understood that additional or alternative steps may be used.

[0073] Although terms such as first, second, third, etc., may be used in this document to describe multiple elements, components, regions, layers, and / or segments, these elements, components, regions, layers, and / or segments should not be limited by these terms. These terms may be used only to distinguish one element, component, region, layer, or segment from another. Unless the context clearly indicates otherwise, terms such as "first," "second," and other numerical terms used herein do not imply order or sequence. Therefore, the first element, component, region, layer, or segment discussed below may be referred to as the second element, component, region, layer, or segment without departing from the teachings of the exemplary embodiments.

[0074] The above description is merely a specific embodiment of this disclosure, enabling those skilled in the art to understand or implement it. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this disclosure. Therefore, this disclosure is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A soft start circuit, characterized by include: A switch has a first terminal, a second terminal, and a control terminal. The switch is connected in series with its first and second terminals in a power supply circuit containing a first power supply unit and a power consumption unit. The control terminal of the switch receives a first control voltage, which is used to control the switch to be turned on or off. The first power supply unit is used to output voltage and current to the power consumption unit. The first diode has its anode coupled to the control terminal of the switch; A delay circuit has an input terminal, an output terminal, and a control terminal. The input terminal of the delay circuit receives a second control voltage, the output terminal of the delay circuit is coupled to a reference ground, and the control terminal of the delay circuit is coupled to the cathode of the first diode. When the first control voltage supplies power to the switch and the second control voltage supplies power to the delay circuit, the first diode is turned on, and the potential of the control terminal of the switch is positively correlated with the potential of the control terminal of the delay circuit.

2. The soft-start circuit of claim 1, wherein, The delay circuit includes a first resistor, a second resistor, and an energy storage capacitor; Wherein, the first end of the first resistor is coupled to the first end of the energy storage capacitor, the second end of the first resistor is coupled to the second end of the energy storage capacitor, the second end of the energy storage capacitor is coupled to the output terminal of the delay circuit, the first end of the second resistor is coupled to the first power supply unit, and the second end of the second resistor is coupled to the first end of the energy storage capacitor.

3. The soft start circuit of claim 2, wherein, The soft-start circuit includes a second diode, the anode of which is coupled to the first terminal of the switch, and the cathode of which is coupled to the control terminal of the switch.

4. The soft-start circuit of claim 3, wherein, The voltage drop across the first resistor during the discharge of the energy storage capacitor is greater than the voltage regulation value of the second diode.

5. The soft-start circuit of claim 1, wherein, The soft-start circuit further includes a third resistor and a fourth resistor. The first end of the third resistor is coupled to the control terminal of the switch, the second end of the third resistor is coupled to the first end of the fourth resistor, and the second end of the fourth resistor is coupled to the second terminal of the switch.

6. The soft start circuit of claim 5, wherein, The soft-start circuit includes a fifth resistor, the first end of which is coupled to the first power supply unit, and the second end of which is coupled to the control terminal of the switch.

7. The soft-start circuit of claim 5, wherein, The soft-start circuit includes a fifth resistor and a second power supply unit. The second power supply unit outputs the first control voltage. The first end of the fifth resistor is coupled to the second power supply unit, and the second end of the fifth resistor is coupled to the control terminal of the switch.

8. The soft-start circuit of claim 1, wherein, The delay circuit includes a first resistor, a second resistor, an energy storage capacitor, and a third power supply unit, wherein the third power supply unit outputs the second control voltage; Wherein, the first end of the first resistor is electrically connected to the first end of the energy storage capacitor, the second end of the first resistor is coupled to the second end of the energy storage capacitor, the second end of the energy storage capacitor is coupled to the output terminal of the delay circuit, the first end of the second resistor is coupled to the third power supply unit, and the second end of the second resistor is coupled to the first end of the energy storage capacitor.

9. The soft start circuit of any of claims 1-8, wherein, The first control voltage is the same as the second control voltage.

10. A wireless charging circuit, comprising: The wireless charging circuit includes a first power supply unit, a power consumption unit, and a soft-start circuit as described in any one of claims 1-9. The first power supply unit includes a power supply terminal and a first ground terminal, and the power consumption unit includes a receiving terminal and a second ground terminal. The switch of the soft-start circuit is connected in series between the power supply terminal and the receiving terminal through the first and second terminals of the switch, or the switch of the soft-start circuit is connected in series between the first ground terminal and the second ground terminal through the first and second terminals of the switch.

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