Power supply circuit and electronic device

Abstract

The application discloses a power supply circuit and electronic equipment, the power supply circuit includes Type-C interface, voltage regulation circuit, first switch unit and first control unit, Type-C interface is used for connecting with external power supply; the input end of voltage regulation circuit is connected with Type-C interface; the input end of first switch unit is connected with voltage regulation circuit, the output end of first switch unit is connected with the load of electronic equipment; first control unit is connected with Type-C interface, voltage regulation circuit and first switch unit respectively, first control unit is configured: in the case that the power supply voltage of external power supply connected with Type-C interface is higher than target voltage, voltage regulation circuit and first switch unit are started, the voltage of the electric energy transmitted by external power supply is reduced to below target voltage through voltage regulation circuit, and the load is powered through first switch unit. In this way, it is beneficial to reduce the selection standard of first switch unit and other unit components, and further beneficial to reduce the generation cost of power supply circuit.

Description

Technical Field

[0001] This application relates to the field of electronic equipment technology, and in particular to a power supply circuit and electronic equipment. Background Technology

[0002] Typically, a USB Type-C interface has a maximum output voltage of 20V, a maximum output current of 5A, and a maximum output power of 100W. To improve the power supply capabilities of the USB Type-C interface, the USB standardization organization (USB-IF) released the PD 3.1 specification (USB Power Delivery Specification Revision 3.1, Version 1.0). PD 3.1 adds the Extended Power Range (EPR) function, specifying that the USB Type-C interface can increase the output voltage to 28V, 36V, or 48V. While maintaining the maximum output current of 5A, the maximum output power of the USB Type-C interface can be increased to 140W, 180W, or 240W.

[0003] Since some motherboards still maintain a maximum input voltage of 20V, manufacturers typically choose to place a power supply circuit between the USB Type-C port and the motherboard. This circuit reduces the voltage received by the USB Type-C port to 20V to power the motherboard. However, conventional power supply circuits are not only complex in structure but also expensive. Summary of the Invention

[0004] To address the aforementioned technical problems, this application provides a power supply circuit and electronic device, the technical solution of which is shown below.

[0005] The first aspect of this application provides a power supply circuit, including: A Type-C interface is provided for connecting to an external power source. A voltage regulating circuit, wherein the input terminal of the voltage regulating circuit is connected to the Type-C interface; The first switching unit has its input terminal connected to the voltage regulating circuit and its output terminal connected to the load of the electronic device. The first control unit is connected to the Type-C interface, the voltage regulation circuit, and the first switching unit. The first control unit is configured to: when it is determined that the supply voltage of the external power supply connected to the Type-C interface is higher than the target voltage, turn on the voltage regulation circuit and the first switching unit, reduce the voltage of the electrical energy transmitted by the external power supply to below the target voltage through the voltage regulation circuit, and supply power to the load through the first switching unit.

[0006] In some embodiments, the power supply circuit further includes: A discharge circuit, wherein the input terminal of the discharge circuit is connected to the Type-C interface and the voltage regulation circuit respectively, and the output terminal of the discharge circuit is grounded; An auxiliary control circuit is connected to the first control unit, the voltage regulation circuit, and the discharge circuit. The auxiliary control circuit is configured to: keep the voltage regulation circuit and the first switching unit open to continue supplying power to the load when the Type-C interface is disconnected from the external power supply and the interface voltage of the Type-C interface is higher than the target voltage; and close the voltage regulation circuit and the first switching unit, and open the discharge circuit to release the remaining power of the Type-C interface when the interface voltage of the Type-C interface drops below the target voltage.

[0007] In some embodiments, the discharge circuit includes a second switching unit, the input terminal of which is connected to the Type-C interface, and the output terminal of which is grounded; the auxiliary control circuit includes a first comparator, a second comparator, a first reference circuit, a second reference circuit, a first sampling circuit, a first OR gate, and a third switching unit; The first reference circuit is capable of generating a first reference voltage; the second reference circuit is capable of generating a second reference voltage, which is the same as the target voltage; the first sampling circuit is connected to the Type-C interface, and the first sampling circuit is capable of generating a first sampling voltage based on the interface voltage of the Type-C interface; One input terminal of the first comparator is connected to the first reference circuit, the other input terminal of the first comparator is connected to the first sampling circuit, the output terminal of the first comparator is connected to the control terminal of the second switching unit, and the output terminal of the first comparator is also grounded through the third switching unit. One input terminal of the second comparator is connected to the second reference circuit, the other input terminal of the second comparator is connected to the first sampling circuit, the output terminal of the second comparator is connected to one input terminal of the first OR gate and the voltage regulation circuit, the other input terminal of the first OR gate is connected to the first control unit, and the output terminal of the first OR gate is connected to the control terminal of the third switching unit.

[0008] In some embodiments, the voltage regulation circuit includes a first field-effect transistor (FET), a second field-effect transistor (FET), a first inductor, and a second control unit. The input terminal of the first FET is connected to the Type-C interface, and the output terminal of the first FET is grounded through the second FET. The second control unit is connected to the first control unit, the input terminal of the first FET, and the input terminal of the second FET, respectively. The input terminal of the first inductor is connected to the output terminal of the first FET, and the output terminal of the first inductor is connected to the first switching unit.

[0009] In some embodiments, the voltage regulation circuit further includes a second sampling circuit and a sampling adjustment circuit, wherein the second control unit is connected to the output terminal of the first inductor through the second sampling circuit, and the second sampling circuit is used to detect the output voltage of the first inductor; The sampling adjustment circuit is connected to the second sampling circuit, the output terminal of the first inductor, and the output terminal of the first switching unit, respectively. The sampling adjustment circuit is configured to reduce the detection value of the second sampling circuit when the output voltage of the first inductor is lower than the output voltage of the first switching unit, so that the second control unit increases the output voltage of the first inductor.

[0010] In some embodiments, the power supply circuit further includes a bypass branch, which is connected in parallel with the voltage regulating circuit and connected to the first control unit, and the bypass branch can bypass the voltage regulating circuit.

[0011] In some embodiments, the first switching unit includes a third field-effect transistor (FET), the input terminal of which is connected to the voltage regulating circuit, the output terminal of which is connected to the load, and the control terminal of which is connected to the first control unit. The first control unit is connected to the output terminal of the voltage regulating circuit via a third sampling circuit, and is also connected to the input terminal of the load via a fourth sampling circuit. The first control unit is configured to control the third FET based on the voltage at the output terminal of the voltage regulating circuit and the voltage at the input terminal of the load.

[0012] In some embodiments, the first switching unit includes a third field-effect transistor and a fourth field-effect transistor. The input terminal of the third field-effect transistor is connected to the voltage regulation circuit, and the output terminal of the third field-effect transistor is connected to the load through the fourth field-effect transistor. The current flow direction of the body diode of the third field-effect transistor is opposite to that of the body diode of the fourth field-effect transistor. The first control unit is connected to the control terminal of the third field-effect transistor and the control terminal of the fourth field-effect transistor, respectively.

[0013] In some embodiments, the power supply circuit further includes: A power interface for connecting to an external power source with a supply voltage below the target voltage, the power interface being different from the Type-C interface; The fourth switching unit has its input terminal connected to the power interface, its output terminal connected to the load of the electronic device, and its control terminal connected to the first control unit.

[0014] A second aspect of this application provides an electronic device, including a load and a power supply circuit as described above.

[0015] In this embodiment of the power supply circuit, the Type-C interface is connected to the load of the electronic device via a voltage regulating circuit and a first switching unit connected in sequence. When the first switching unit determines that the supply voltage of the external power source connected to the Type-C interface is higher than the target voltage, it activates the voltage regulating circuit and the first switching unit. The voltage regulating circuit reduces the voltage of the electrical energy transmitted from the external power source to below the target voltage before transmitting it to the first switching unit, which then transmits it to the load of the electronic device to power the load. Thus, the first switching unit located on the output side of the voltage regulating circuit, as well as other components in the power supply circuit, can operate at relatively low voltages. The structural design is reasonable, which helps to reduce the selection criteria for the first switching unit and other components, thereby reducing the manufacturing cost of the power supply circuit. Attached Figure Description

[0016] Figure 1 This is a circuit block diagram of the power supply circuit according to the first embodiment of this application; Figure 2 This is a circuit block diagram of the power supply circuit according to the second embodiment of this application; Figure 3 This is a circuit diagram of the power supply circuit according to the second embodiment of this application; Figure 4 This is a circuit diagram of the discharge circuit and auxiliary control circuit in the second embodiment of this application; Figure 5 This is a circuit diagram of the voltage regulation circuit in the second embodiment of this application; Figure 6 This is a circuit block diagram of the power supply circuit according to the third embodiment of this application. Detailed Implementation

[0017] Various embodiments and features of this application are described herein with reference to the accompanying drawings.

[0018] It should be understood that various modifications can be made to the embodiments described herein. Therefore, the above description should not be considered as limiting, but merely as an example of embodiments. Other modifications within the scope and spirit of this application will be apparent to those skilled in the art.

[0019] The accompanying drawings, which are included in and form part of this specification, illustrate embodiments of the present application and, together with the general description of the present application given above and the detailed description of the embodiments given below, serve to explain the principles of the present application.

[0020] These and other features of this application will become apparent from the following description of preferred forms of embodiments given as non-limiting examples, with reference to the accompanying drawings.

[0021] The above and other aspects, features and advantages of this application will become more apparent when taken in conjunction with the accompanying drawings and in view of the following detailed description.

[0022] Specific embodiments of this application are described thereafter with reference to the accompanying drawings; however, it should be understood that the claimed embodiments are merely examples of this application, which can be implemented in various ways. Well-known and / or repeated functions and structures are not described in detail to avoid unnecessary or redundant details that could obscure the application. Therefore, the specific structural and functional details claimed herein are not intended to be limiting, but merely serve as the basis and representative basis for the claims to teach those skilled in the art to use this application in a variety of substantially any suitable detailed structures.

[0023] This specification may use the phrases “in one embodiment,” “in another embodiment,” “in yet another embodiment,” or “in other embodiments,” all of which may refer to one or more of the same or different embodiments according to this application.

[0024] It should also be understood that the first, second, third, fourth and various numerical designations used herein are merely for descriptive convenience and are not intended to limit the scope of this application.

[0025] This application provides a power supply circuit for use in electronic devices, including but not limited to laptops, tablets, smartphones, etc., without limiting the type of electronic device. Figure 1 This is a circuit block diagram of the power supply circuit according to the first embodiment of this application. See also: Figure 1 As shown, the power supply circuit of this application embodiment includes a Type-C interface 110, a voltage regulation circuit, a first switching unit, and a first control unit.

[0026] The Type-C interface 110 is used to connect to an external power source. Optionally, the Type-C interface 110 may be a Type-C interface 110 conforming to the PD 3.1 specification (USB Power Delivery Specification Revision 3.1, Version 1.0) so that the maximum supply voltage of the Type-C interface 110 can be increased to above 20V.

[0027] The input terminal of the voltage regulating circuit is connected to the Type-C interface 110. Optionally, the input terminal of the voltage regulating circuit can be connected to the VBUS pin of the Type-C interface 110. For example, the Type-C interface 110 may include VBUS1, VBUS2, VBUS3, and VBUS4 pins, which can be connected in parallel and all connected to the input terminal of the voltage regulating circuit. Figure 3 As shown.

[0028] The input terminal of the first switching unit is connected to the voltage regulating circuit, and the output terminal of the first switching unit is connected to the load of the electronic device. The first switching unit can turn on the voltage regulating circuit and the load of the electronic device to supply power to the load. The first switching unit can also turn off the voltage regulating circuit and the load to stop supplying power to the load and prevent power from flowing back from the load side to the voltage regulating circuit.

[0029] The first control unit is connected to the Type-C interface 110, the voltage regulation circuit, and the first switching unit. The first control unit is configured to: when it is determined that the supply voltage of the external power supply connected to the Type-C interface 110 is higher than the target voltage, activate the voltage regulation circuit and the first switching unit, reduce the voltage of the electrical energy transmitted by the external power supply to below the target voltage through the voltage regulation circuit, and supply power to the load through the first switching unit.

[0030] Optionally, the target voltage may include a first target voltage and a second target voltage lower than the first target voltage. For example, the first target voltage may be 22V, and the second target voltage may be 20V. When the voltage regulating circuit is in the off state, the first control unit may be configured to turn on the voltage regulating circuit and the first switching unit when the interface voltage of the Type-C interface 110 is higher than the first target voltage, thereby reducing the voltage to below the second target voltage through the voltage regulating circuit to supply power to the load. When the voltage regulating circuit is in the on state, the first control unit may be configured to keep the voltage regulating circuit and the first switching unit on when the interface voltage of the Type-C interface 110 is higher than the second target voltage. This avoids triggering the voltage regulating circuit and the first switching unit to turn on when there are small, uncontrolled fluctuations in the interface voltage of the Type-C interface 110.

[0031] Optionally, the first switching unit can determine the interface voltage of the Type-C interface 110 in various ways. For example, the first switching unit can be connected to one or more CC pins of the Type-C interface 110, and the first switching unit can interact with an external power supply through the Type-C interface 110 to determine the supply voltage of the external power supply. Alternatively, the first switching unit can also be connected to the VBUS pin of the Type-C interface 110 via a sampling circuit to detect the interface voltage of the Type-C interface 110.

[0032] Optionally, the first control unit may include a single controller or multiple controllers. For example, the first control unit may include a power controller 141 and an embedded controller 142. The power controller 141 may be connected to the Type-C interface 110, the voltage regulation circuit, the first switching unit, and the embedded controller 142, respectively. The power controller 141 may be configured to control the voltage regulation circuit and the first switching unit under the instruction of the embedded controller 142, such as... Figure 1 As shown. That is, the embedded controller 142 can be configured to have higher control authority than the power controller 141.

[0033] In this embodiment of the power supply circuit, the Type-C interface 110 is connected to the load of the electronic device via a voltage regulating circuit and a first switching unit connected in sequence. When the first switching unit determines that the supply voltage of the external power source connected to the Type-C interface 110 is higher than the target voltage, it activates the voltage regulating circuit and the first switching unit. The voltage regulating circuit reduces the voltage of the electrical energy transmitted from the external power source to below the target voltage before transmitting it to the first switching unit, which then transmits it to the load of the electronic device to supply power. Thus, the first switching unit located on the output side of the voltage regulating circuit, as well as other components in the power supply circuit, can operate at relatively low voltages. The structural design is reasonable, which helps to reduce the selection criteria for the first switching unit and other components, thereby reducing the manufacturing cost of the power supply circuit.

[0034] Cooperate Figure 2 As shown, in some embodiments, the power supply circuit may further include a power interface 160 and a fourth switching unit. The power interface 160 is used to connect to an external power source with a supply voltage below the target voltage, and this power interface 160 is different from the Type-C interface 110. The input terminal of the fourth switching unit is connected to the power interface 160, the output terminal of the fourth switching unit is connected to the load of the electronic device, and the control terminal of the fourth switching unit is connected to the first control unit. Thus, multiple power supply options can be provided for the electronic device.

[0035] Optionally, the power interface 160 may be a direct current (DC) power interface. For example, a circular DC interface, a square DC interface, etc.

[0036] Optionally, the fourth switching unit may include a switch control circuit 171 and a field-effect transistor (FET) PQ1. The input terminal of the FET PQ1 can be connected to the power interface 160, and the output terminal of the FET PQ1 can be connected to the load. The control terminal of the FET PQ1 can be connected to the first control unit through the switch control circuit 171, such as... Figure 2 As shown, this results in lower production costs.

[0037] Optionally, the fourth switching unit may include a switch control circuit 171, a field-effect transistor (FET) PQ1, and a field-effect transistor (FET) PQ2. The input terminal of FET PQ1 can be connected to a power interface 160, and the output terminal of FET PQ1 can be connected to a load through FET PQ2. The current flow direction of the body diode of FET PQ1 is opposite to that of the body diode of FET PQ2. The first control unit can be connected to the control terminals of FET PQ1 and FET PQ2 respectively through the switch control circuit 171, such as... Figure 6As shown. This enables bidirectional cutoff, preventing power from the Type-C interface 110 from flowing back to the power interface 160.

[0038] Optionally, the power interface 160 and the Type-C interface 110 may have different power supply priorities. The first control unit may be configured to select either the power interface 160 or the Type-C interface 110 to supply power to the load of the electronic device based on the power supply priority. For example, the power supply priority of the power interface 160 may be higher than that of the Type-C interface 110. If it is determined that both the power interface 160 and the Type-C interface 110 are connected to an external power source, the first control unit activates the fourth switching unit, deactivates the voltage regulation circuit and the first switching unit, and supplies power to the load through the power interface 160. Alternatively, for example, the power supply priority of the Type-C interface 110 may be higher than that of the power interface 160. If it is determined that both the power interface 160 and the Type-C interface 110 are connected to an external power source, the first control unit activates the voltage regulation circuit and the first switching unit, supplies power to the load through the Type-C interface 110, and deactivates the fourth switching unit to prevent power from the Type-C interface 110 from flowing back to the power interface 160.

[0039] Optionally, the first control unit can also be configured to select either the power interface 160 or the Type-C interface 110 to supply power to the load based on the order in which the power interface 160 and the Type-C interface 110 are connected to the external power source. That is, if the power interface 160 is connected to the external power source before the Type-C interface 110, the first control unit preferentially selects the power interface 160 to supply power to the load. If the Type-C interface 110 is connected to the external power source before the power interface 160, the first control unit preferentially selects the Type-C interface 110 to supply power to the load.

[0040] Cooperate Figure 2As shown, in some embodiments, the power supply circuit may further include a discharge circuit 180 and an auxiliary control circuit 190. The input terminal of the discharge circuit 180 is connected to the Type-C interface 110 and the voltage regulation circuit, respectively, and the output terminal of the discharge circuit 180 is grounded. The auxiliary control circuit 190 is connected to the first control unit, the voltage regulation circuit, and the discharge circuit 180, respectively. The auxiliary control circuit 190 is configured to: keep the voltage regulation circuit and the first switching unit open to continue supplying power to the load when the Type-C interface 110 is disconnected from the external power supply and the interface voltage of the Type-C interface 110 is higher than the target voltage; and close the voltage regulation circuit and the first switching unit, open the discharge circuit 180, and release the remaining power of the Type-C interface 110 when the interface voltage of the Type-C interface 110 drops below the target voltage.

[0041] For example, the external power supply connected to the Type-C interface 110 can have a supply voltage of 48V, and the target voltage can be 20V. When the external power supply is disconnected from the Type-C interface 110, the first control unit does not immediately shut down the voltage regulation circuit and the first switching unit, but keeps them open to continue supplying power to the load. This allows a portion of the remaining charge in the Type-C interface 110 to be quickly transferred to the load, and the interface voltage of the Type-C interface 110 can be quickly reduced from 48V to 20V. When the interface voltage of the Type-C interface 110 drops to 20V, the auxiliary control circuit 190 shuts down the voltage regulation unit and the first switching unit, and turns on the discharge circuit 180 to release the remaining charge in the Type-C interface 110 to ground. This improves the discharge speed of the Type-C interface 110 and reduces the current requirements of the discharge circuit 180, thus reducing production costs.

[0042] Cooperate Figure 3 and Figure 4 As shown, in some embodiments, the discharge circuit 180 includes a second switching unit. The input terminal of the second switching unit is connected to the Type-C interface 110, and the output terminal of the second switching unit is grounded. Optionally, the second switching unit may include a field-effect transistor PQ16 and a resistor PR6. The input terminal of the field-effect transistor PQ16 can be connected to the VBUS pin of the Type-C interface 110 through the resistor PR6, and the output terminal of the field-effect transistor PQ16 can be grounded. The control terminal of the field-effect transistor PQ16 is connected to the auxiliary control circuit 190.

[0043] The auxiliary control circuit 190 includes a first comparator PU1A, a second comparator PU4A, a first reference circuit, a second reference circuit, a first sampling circuit, a first OR gate PU3A, and a third switching unit. The first reference circuit generates a first reference voltage. The third target voltage can be a lower threshold for the Type-C interface 110 to discharge. That is, when the Type-C interface 110 discharges to the third target voltage, the discharge operation can be paused. For example, the third target voltage can be 5V, and the first reference voltage can be 0.525V.

[0044] The second reference circuit is capable of generating a second reference voltage. Optionally, the second reference voltage can be used to identify either the first target voltage or the second target voltage. For example, the second reference voltage can be proportional to the VBUS pin voltage of the Type-C interface 110 at a ratio of 1:10. The first target voltage can be 22V, and the second target voltage can be 20V. The second reference circuit is configured to generate reference voltages of 2.2V and 2.0V.

[0045] The first sampling circuit is connected to the Type-C interface 110, and the first sampling circuit can generate a first sampling voltage based on the interface voltage of the Type-C interface 110. Optionally, the first sampling voltage can be used to represent the interface voltage of the Type-C interface 110. For example, the first sampling voltage and the interface voltage of the Type-C interface 110 can be in a 1:10 ratio. When the interface voltage of the Type-C interface 110 is 48V, the first sampling voltage is 4.8V, and so on.

[0046] One input terminal of the first comparator PU1A is connected to the first reference circuit, the other input terminal of the first comparator PU1A is connected to the first sampling circuit, the output terminal of the first comparator PU1A is connected to the control terminal of the second switching unit, and the output terminal of the first comparator PU1A is also grounded through the third switching unit.

[0047] One input terminal of the second comparator PU4A is connected to the second reference circuit, the other input terminal of the second comparator PU4A is connected to the first sampling circuit, the output terminal of the second comparator PU4A is connected to one input terminal of the first OR gate PU3A and the voltage regulation circuit, the other input terminal of the first OR gate PU3A is connected to the first control unit, and the output terminal of the first OR gate PU3A is connected to the control terminal of the third switching unit.

[0048] When the Type-C interface 110 is connected to an external power supply, the first comparator PU1A compares the first reference voltage and the first sampled voltage. If the supply voltage of the external power supply connected to the Type-C interface 110 is higher than the third target voltage, the first comparator PU1A outputs a high-level signal. The first control unit can interact with the external power supply. If it is determined that the supply voltage of the external power supply is higher than the first target voltage, the first control unit can output a high-level signal to the first OR gate PU3A. The first OR gate PU3A outputs a high-level signal to the third switching unit, turning on the third switching unit. The control of the second switching unit is grounded through the third switching unit. Therefore, even if the first comparator PU1A outputs a high-level signal, the control terminal of the second switching unit receives a low-level signal, and the second switching unit remains in the open state, not performing a discharge operation.

[0049] The second comparator PU4A compares the first sampled voltage and the second reference voltage. If, based on the first sampled voltage and the second reference voltage, it is determined that the supply voltage of the external power source is higher than the first target voltage, then the second comparator PU4A outputs a high-level signal to the voltage regulation circuit. In response to this high-level signal, the voltage regulation circuit performs a step-down operation, reducing the voltage of the received power source to below the second target voltage.

[0050] When the external power supply is disconnected from the Type-C interface 110, the interface voltage of the Type-C interface 110 remains higher than the third target voltage, and the first comparator PU1A continues to output a high-level signal. The first control unit can detect the disconnection of the external power supply from the Type-C interface 110 through the CC pin of the Type-C interface 110, and the first control unit outputs a low-level signal to the first OR gate PU3A. However, the first control unit still keeps the first switching unit in the ON state. Since the interface voltage of the Type-C interface 110 is higher than the second target voltage at this time, the second comparator PU4A continues to output a high-level signal, the voltage regulation circuit remains ON, and power is continuously supplied to the load through the voltage regulation circuit and the first switching unit. The remaining charge at the Type-C interface 110 gradually decreases, and the interface voltage of the Type-C interface 110 also gradually decreases.

[0051] Until the interface voltage of Type-C interface 110 drops below the second target voltage, the second comparator outputs a low-level signal. Since both inputs of the second OR gate receive low-level signals, the second OR gate outputs a low-level signal to the third switching unit, disconnecting the third switching unit. The input of the second switching unit receives a high-level signal from the first comparator PU1A, turning the second switching unit on. Type-C interface 110 is grounded through the second switching unit, and the remaining power of Type-C interface 110 is released to ground via the second switching unit. In this way, through the cooperation of the first switching unit and the auxiliary control circuit 190, a portion of the remaining power of Type-C interface 110 can be released to the load, improving energy utilization and reducing the current requirements of the discharge circuit 180, which is beneficial for reducing production costs.

[0052] Optionally, the first sampling circuit may include resistors PR9 and PR11, such as... Figure 4 As shown. One end of resistor PR9 is connected to the VBUS pin of the Type-C interface 110, and the other end of resistor PR9 is grounded through resistor PR11. The other input of the first comparator PU1A and the other input of the second comparator PU4A can be connected between resistors PR9 and PR11.

[0053] Optionally, the first reference circuit may include resistors PR7 and PR8, such as... Figure 4 As shown. One end of resistor PR7 is connected to the 3.3V system power supply VCC of the electronic device, and the other end of resistor PR7 is grounded through resistor PR8. One input of the first comparator PU1A can be connected between resistors PR7 and PR8. The first reference circuit can be configured to output a 0.525V reference voltage.

[0054] Optionally, the second reference circuit may include resistors PR14, PR17, PR18, and field-effect transistor PQ10, such as... Figure 4As shown. One end of resistor PR14 is connected to the 3.3V system power supply terminal VCC of the electronic device, and the other end of resistor PR14 is grounded through resistor PR18. One end of resistor PR17 is connected between resistors PR14 and PR18, and the other end of resistor PR17 is grounded through field-effect transistor PQ10. The control terminal of field-effect transistor PQ10 is connected to the output terminal of the second comparator PU4A. When the external power supply is not connected to the Type-C interface 110, the second comparator PU4A outputs a low-level signal, field-effect transistor PQ10 is turned off, and the second reference circuit outputs a 2.2V reference voltage to the second comparator PU4A. When the second comparator PU4A determines that the interface voltage of the Type-C interface 110 is higher than the first target voltage, the second comparator PU4A outputs a high-level signal, turning on the voltage regulation circuit. At the same time, field-effect transistor PQ10 is turned on, resistors PR17 and PR18 are connected in parallel, and the second reference circuit outputs a 2.0V reference voltage to the second comparator PU4A.

[0055] Optionally, the third switching unit may include a field-effect transistor (FET) PQ7. The auxiliary control circuit 190 may also include a field-effect transistor (FET) PQ13. The input terminal of FET PQ13 may be connected to the other input terminal of the second comparator PU4A, the output terminal of FET PQ13 may be grounded, and the control terminal of FET PQ13 may be connected to the first control unit. For example, the control terminal of FET PQ13 may be connected to a power controller 141 or an embedded controller 142. In this way, FET PQ13 can, in response to the control of the first controller, pull down the input voltage of the other input terminal of the second comparator PU4A, thereby actively shutting down the voltage regulation circuit.

[0056] In specific implementation, the voltage regulation circuit can have various circuit structures. The structure and principle of the voltage regulation circuit are illustrated below, but it should not be understood that the voltage regulation circuit is limited to the following structure, as long as it can reduce the voltage of the electrical energy received by the Type-C interface 110 to below the target voltage.

[0057] Cooperate Figure 2 , Figure 3 and Figure 5As shown, in some embodiments, the voltage regulation circuit includes a first field-effect transistor (FET) PQ5, a second field-effect transistor (FET) PQ6, a first inductor PL1, and a second control unit 121. The input terminal of the first FET PQ5 is connected to the Type-C interface 110, and the output terminal of the first FET PQ5 is grounded through the second FET PQ6. The second control unit 121 is connected to the first control unit, the input terminal of the first FET PQ5, and the input terminal of the second FET PQ6, respectively. The input terminal of the first inductor PL1 is connected to the output terminal of the first FET PQ5, and the output terminal of the first inductor PL1 is connected to the first switching unit. When the first control unit determines that the supply voltage of the external power supply connected to the Type-C interface 110 is higher than the target voltage, it can send a signal to the second switching unit. The second switching unit can alternately turn on the first FET PQ5 and the second FET PQ6 to adjust the duty cycle of the voltage regulation circuit, thereby reducing the voltage below the target voltage. For example, the voltage of the power received by the Type-C interface 110 can be reduced from 28V, 36V, or 48V to below 20V. This voltage regulation circuit is not only simple in structure and easy to control, but also has a wide adjustable range.

[0058] In some embodiments, the voltage regulating circuit further includes a second sampling circuit and a sampling adjustment circuit. The second control unit 121 is connected to the output terminal of the first inductor PL1 via the second sampling circuit, which is used to detect the output voltage of the first inductor PL1. The sampling adjustment circuit is connected to the second sampling circuit, the output terminal of the first inductor PL1, and the output terminal of the first switching unit, respectively. The sampling adjustment circuit is configured to: when the output voltage of the first inductor PL1 is lower than the output voltage of the first switching unit, decrease the detection value of the second sampling circuit, so that the second control unit 121 increases the output voltage of the first inductor PL1. Thus, when the voltage regulating circuit and the first switching unit are in the ON state, it can be ensured that the voltage regulating circuit stably supplies power to the load.

[0059] Optionally, the second sampling circuit may include Figure 5 The sampling and adjustment circuit includes resistors PR12 and PR15, and comprises comparator PU5A, field-effect transistor PQ14, field-effect transistor PQ9, and auxiliary circuitry. It should be noted that the voltage regulation circuit is not limited to the above structure; it may also include other electronic components, such as... Figure 5 Medium capacitor PC5 and capacitor PC7, etc.

[0060] Cooperate Figure 6As shown, in some embodiments, the power supply circuit further includes a bypass branch 200, which is connected in parallel with the voltage regulating circuit and connected to the first control unit. The bypass branch 200 can bypass the voltage regulating circuit. The first controller can be configured to: shut down the voltage regulating circuit and turn on the bypass branch 200 and the first switching unit when it is determined that the supply voltage of the power supply connected to the Type-C interface 110 is less than or equal to the target voltage. In this way, electrical energy flows through the bypass branch 200 and the first switching unit to supply power to the load, which can reduce power loss and is beneficial to reducing the energy consumption level of electronic devices.

[0061] Optionally, the bypass branch 200 may include an electronic fuse. The input terminal of the electronic fuse may be connected to the VBUS pin of the Type-C interface 110, the output terminal of the electronic fuse may be connected to the input terminal of the first switching unit, and the control terminal of the electronic fuse may be connected to the power controller 141. The power controller 141 can turn the electronic fuse on or off. Of course, the bypass branch 200 can also be formed by switching devices, such as transistors, field-effect transistors, etc.

[0062] It should be noted that, in practical implementation, the bypass branch 200 may not be required. Without the bypass branch 200, if it is determined that the supply voltage of the external power supply connected to the Type-C interface 110 is less than or equal to the target voltage, the first MOSFET PQ5 can be kept normally open, and the second MOSFET PQ6 can be turned off. This also achieves the goal of not performing a voltage reduction operation.

[0063] Cooperate Figure 6 As shown, in some embodiments, the first switching unit may include a third field-effect transistor (FET) PQ4 and a fourth FET PQ3. The input terminal of the third FET PQ4 is connected to the voltage regulation circuit, and the output terminal of the third FET PQ4 is connected to the load through the fourth FET PQ3. The current flow direction of the body diode of the third FET PQ4 is opposite to that of the body diode of the fourth FET PQ3. The first control unit is connected to the control terminals of the third FET PQ4 and the fourth FET PQ3, respectively. Thus, when both the third FET PQ4 and the fourth FET PQ3 are in the off state, bidirectional blocking can be achieved, preventing backflow of power from the system to the voltage regulation circuit.

[0064] Cooperate Figure 2As shown, in some embodiments, the first switching unit includes a third field-effect transistor (FET) PQ4. The input terminal of the third FET PQ4 is connected to the voltage regulating circuit, the output terminal of the third FET is connected to the load, and the control terminal of the third FET PQ4 is connected to the first control unit. The first control unit is connected to the output terminal of the voltage regulating circuit via a third sampling circuit 131, and is also connected to the input terminal of the load via a fourth sampling circuit 132. The first control unit can be configured to control the third FET PQ4 based on the voltage at the output terminal of the voltage regulating circuit and the voltage at the input terminal of the load. For example, the first control unit can be configured to turn on the third FET PQ4 when it is determined that the Type-C interface 110 is connected to an external power source and the output voltage of the voltage regulating circuit is higher than the input voltage of the load. In this way, the purpose of preventing power backflow from the system end to the voltage regulating circuit can be achieved through a single FET, which is beneficial to reducing production costs.

[0065] This application also provides an electronic device, including a load and a power supply circuit as described in any embodiment. Since the power supply circuit can reduce the voltage of the electrical energy received by the Type-C interface 110 to below a target voltage to power the load, and the production cost of this power supply circuit is low, the electronic device using the above power supply circuit also has a low production cost. Optionally, the electronic device includes, but is not limited to, laptops, tablets, smartphones, etc.

[0066] The above embodiments are merely exemplary embodiments of this application and are not intended to limit this application. The scope of protection of this application is defined by the claims. Those skilled in the art can make various modifications or equivalent substitutions to this application within its substance and scope of protection, and such modifications or equivalent substitutions should also be considered to fall within the scope of protection of this application.

Claims

1. A power supply circuit, characterized in that, include: A Type-C interface is provided for connecting to an external power source. A voltage regulating circuit, wherein the input terminal of the voltage regulating circuit is connected to the Type-C interface; The first switching unit has its input terminal connected to the voltage regulating circuit and its output terminal connected to the load of the electronic device. A first control unit is connected to the Type-C interface, the voltage regulation circuit, and the first switching unit. The first control unit is configured to: when it is determined that the supply voltage of the external power supply connected to the Type-C interface is higher than the target voltage, activate the voltage regulation circuit and the first switching unit, reduce the voltage of the electrical energy transmitted by the external power supply to below the target voltage through the voltage regulation circuit, and supply power to the load through the first switching unit; The power supply circuit also includes: A discharge circuit, wherein the input terminal of the discharge circuit is connected to the Type-C interface and the voltage regulation circuit respectively, and the output terminal of the discharge circuit is grounded; An auxiliary control circuit is connected to the first control unit, the voltage regulation circuit, and the discharge circuit. The auxiliary control circuit is configured to: keep the voltage regulation circuit and the first switching unit open to continue supplying power to the load when the Type-C interface is disconnected from the external power supply and the interface voltage of the Type-C interface is higher than the target voltage; and close the voltage regulation circuit and the first switching unit, and open the discharge circuit to release the remaining power of the Type-C interface when the interface voltage of the Type-C interface drops below the target voltage. The discharge circuit includes a second switching unit, the input terminal of which is connected to the Type-C interface, and the output terminal of which is grounded; the auxiliary control circuit includes a first comparator, a second comparator, a first reference circuit, a second reference circuit, a first sampling circuit, a first OR gate, and a third switching unit; The first reference circuit is capable of generating a first reference voltage; the second reference circuit is capable of generating a second reference voltage, which is the same as the target voltage; the first sampling circuit is connected to the Type-C interface, and the first sampling circuit is capable of generating a first sampling voltage based on the interface voltage of the Type-C interface; One input terminal of the first comparator is connected to the first reference circuit, the other input terminal of the first comparator is connected to the first sampling circuit, the output terminal of the first comparator is connected to the control terminal of the second switching unit, and the output terminal of the first comparator is also grounded through the third switching unit. One input terminal of the second comparator is connected to the second reference circuit, the other input terminal of the second comparator is connected to the first sampling circuit, the output terminal of the second comparator is connected to one input terminal of the first OR gate and the voltage regulation circuit, the other input terminal of the first OR gate is connected to the first control unit, and the output terminal of the first OR gate is connected to the control terminal of the third switching unit.

2. The power supply circuit according to claim 1, characterized in that, The voltage regulation circuit includes a first field-effect transistor (FET), a second field-effect transistor (FET), a first inductor, and a second control unit. The input terminal of the first FET is connected to the Type-C interface, and the output terminal of the first FET is grounded through the second FET. The second control unit is connected to the first control unit, the input terminal of the first FET, and the input terminal of the second FET, respectively. The input terminal of the first inductor is connected to the output terminal of the first FET, and the output terminal of the first inductor is connected to the first switching unit.

3. The power supply circuit according to claim 2, characterized in that, The voltage regulation circuit further includes a second sampling circuit and a sampling adjustment circuit. The second control unit is connected to the output terminal of the first inductor through the second sampling circuit. The second sampling circuit is used to detect the output voltage of the first inductor. The sampling adjustment circuit is connected to the second sampling circuit, the output terminal of the first inductor, and the output terminal of the first switching unit, respectively. The sampling adjustment circuit is configured to reduce the detection value of the second sampling circuit when the output voltage of the first inductor is lower than the output voltage of the first switching unit, so that the second control unit increases the output voltage of the first inductor.

4. The power supply circuit according to claim 3, characterized in that, The power supply circuit also includes a bypass branch, which is connected in parallel with the voltage regulating circuit and connected to the first control unit. The bypass branch can bypass the voltage regulating circuit.

5. The power supply circuit according to claim 1, characterized in that, The first switching unit includes a third field-effect transistor (FET). The input terminal of the third FET is connected to the voltage regulating circuit, the output terminal of the third FET is connected to the load, and the control terminal of the third FET is connected to the first control unit. The first control unit is connected to the output terminal of the voltage regulating circuit through a third sampling circuit, and the first control unit is also connected to the input terminal of the load through a fourth sampling circuit. The first control unit is configured to control the third FET based on the voltage at the output terminal of the voltage regulating circuit and the voltage at the input terminal of the load.

6. The power supply circuit according to claim 1, characterized in that, The first switching unit includes a third field-effect transistor and a fourth field-effect transistor. The input terminal of the third field-effect transistor is connected to the voltage regulation circuit, and the output terminal of the third field-effect transistor is connected to the load through the fourth field-effect transistor. The current flow direction of the body diode of the third field-effect transistor is opposite to that of the body diode of the fourth field-effect transistor. The first control unit is connected to the control terminal of the third field-effect transistor and the control terminal of the fourth field-effect transistor, respectively.

7. The power supply circuit according to claim 1, characterized in that, The power supply circuit also includes: A power interface for connecting to an external power source with a supply voltage below the target voltage, the power interface being different from the Type-C interface; The fourth switching unit has its input terminal connected to the power interface, its output terminal connected to the load of the electronic device, and its control terminal connected to the first control unit.

8. An electronic device, characterized in that, Includes a load and a power supply circuit as described in any one of claims 1 to 7.

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