USB voltage stabilizing circuit

Abstract

A USB voltage stabilizing circuit comprises a power supply module, a voltage stabilizing module and a voltage stabilizing element, the power supply module is used for providing a power supply voltage, an input end of the voltage stabilizing module is electrically connected with the power supply module, an output end of the voltage stabilizing module is electrically connected with a USB interface, and the output end of the voltage stabilizing module is also electrically connected to the USB interface through the voltage stabilizing element, when the USB interface is connected with a load, the voltage stabilizing module directly outputs the power supply voltage to the USB interface, and when the USB interface is not connected with a load, the voltage stabilizing module outputs the power supply voltage to the USB interface through the voltage stabilizing element. By adding a voltage stabilizing element between the voltage stabilizing module and the USB interface, the circuit can be effectively stabilized when the current in the USB voltage stabilizing circuit instantaneously changes greatly, and the output power supply voltage is more stable and reliable.

Description

Technical Field

[0001] This invention relates to a USB voltage regulator circuit. Background Technology

[0002] Currently, the use of Type-C interfaces on motherboards is becoming increasingly common. However, in some Type-C power supply circuits, when the current in the Type-C power supply circuit suddenly changes significantly, a voltage drop will occur in the output power supply voltage. This will lead to unstable output power supply voltage. Summary of the Invention

[0003] In view of the above, it is necessary to provide a USB voltage regulator circuit that can stably output power supply voltage.

[0004] A USB voltage regulator circuit includes a power module, a voltage regulator module, and a voltage regulator element. The power module provides a power supply voltage. The input terminal of the voltage regulator module is electrically connected to the power module, and the output terminal of the voltage regulator module is electrically connected to a USB interface. The output terminal of the voltage regulator module is also electrically connected to the USB interface through the voltage regulator element. When a load is connected to the USB interface, the voltage regulator module directly outputs the power supply voltage to the USB interface. When no load is connected to the USB interface, the voltage regulator module outputs the power supply voltage to the USB interface through the voltage regulator element.

[0005] Preferably, the voltage regulator is a Schottky diode.

[0006] Preferably, the voltage regulator module includes a first filter element, an integrated chip, and a second filter element. One end of the first filter element is electrically connected to the power module and the integrated chip, and the other end of the first filter element is grounded. One end of the second filter element is electrically connected to the integrated chip, and the other end of the second filter element is grounded.

[0007] Preferably, the integrated chip includes an input terminal, a first output terminal, a second output terminal, and a filter terminal. The input terminal of the integrated chip is electrically connected between the power module and the first filter element. The first output terminal is directly electrically connected to the USB interface. The second output terminal is electrically connected to the USB interface through the voltage regulator element. The filter terminal is grounded through the second filter element.

[0008] Preferably, the voltage regulator module further includes a control unit, and the integrated chip further includes an enable terminal. The control unit is electrically connected to the enable terminal. The control unit is used to detect whether the USB interface is connected to a load. When the control unit detects that the USB interface is connected to a load, the control unit outputs a first level signal to the enable terminal to control the integrated chip to output the power supply voltage to the USB interface through the first output terminal. When the control unit detects that the USB interface is not connected to a load, the control unit outputs a second level signal to the enable terminal to control the integrated chip to output the power supply voltage to the USB interface through the second output terminal and the voltage regulator element.

[0009] Preferably, the voltage regulator module further includes a protection element, one end of which is electrically connected between the USB interface, one end of the voltage regulator and the first output terminal, and the other end of which is grounded. The protection element is used to prevent inversion.

[0010] Preferably, the integrated chip includes a first electronic switch and a second electronic switch. A first terminal of the first electronic switch is electrically connected to the input terminal of the integrated chip, a second terminal of the first electronic switch is electrically connected to the enable terminal, a third terminal of the first electronic switch is electrically connected to the second output terminal, one end of the voltage regulator element, and the third terminal of the second electronic switch, a first terminal of the second electronic switch is electrically connected to the first output terminal and the other end of the voltage regulator element, and a second terminal of the second electronic switch is electrically connected to the enable terminal.

[0011] Preferably, the integrated chip further includes a third electronic switch, an operational comparator, and a voltage regulator. The first terminal of the third electronic switch is electrically connected to the enable terminal and the second terminal of the second electronic switch. The third terminal of the third electronic switch is grounded. The second terminal of the third electronic switch is electrically connected to the output terminal of the operational comparator. The positive input terminal of the operational comparator is electrically connected to the first terminal of the second electronic switch, the first output terminal, and the other end of the voltage regulator. The negative input terminal of the operational comparator is electrically connected to the input terminal of the integrated chip through the voltage regulator. Preferably, the integrated chip further includes a first diode and a second diode. The cathode of the first diode is electrically connected to the input terminal of the integrated chip, the first terminal of the first electronic switch, and the anode of the voltage regulator. The anode of the first diode is electrically connected to the second output terminal of the integrated chip, one end of the voltage regulator element, and the anode of the second diode. The cathode of the second diode is electrically connected to the first output terminal of the integrated chip, the cathode of the voltage regulator element, and the positive input terminal of the operational comparator. The first diode and the second diode are used to protect the first electronic switch and the second electronic switch to prevent them from being reversed.

[0012] Preferably, the first electronic switch, the second electronic switch, and the third electronic switch are P-type MOSFETs with a turn-on voltage of 35mV.

[0013] This application adds a voltage regulator between the voltage regulator module and the USB interface, which can effectively stabilize the circuit when the current in the USB voltage regulator circuit changes rapidly, thereby ensuring a more stable and reliable output power supply voltage. Attached Figure Description

[0014] Figure 1 This is a functional block diagram of the USB voltage regulator circuit in a preferred embodiment of the present invention.

[0015] Figure 2 yes Figure 1 The circuit diagram of the USB voltage regulator circuit is shown.

[0016] Figure 3 yes Figure 2 The diagram shows the internal circuit of the integrated chip in the USB voltage regulator circuit.

[0017] Explanation of main component symbols The following detailed description, in conjunction with the accompanying drawings, will further illustrate the present invention. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] It should be noted that when one component is referred to as "electrically connected" to another component, it can be directly on the other component or there can be an intervening component. When one component is considered to be "electrically connected" to another component, it can be a contact connection, such as a wire connection, or a non-contact connection, such as a non-contact coupling.

[0020] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0021] The following detailed description of some embodiments of the present invention is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0022] Please see Figure 1 and Figure 2 This application provides a USB voltage regulator circuit 400. The USB voltage regulator circuit 400 includes a voltage regulator module 100 and a power supply module 200. The power supply module 200 is electrically connected to the voltage regulator module 100 and provides power voltage to the voltage regulator module 100. The voltage regulator module 100 is electrically connected between the power supply module 200 and a USB interface 300, and outputs the received power voltage to the USB interface 300, so that the power voltage can be output to a load through the USB interface 300.

[0023] In this embodiment, the input terminal of the voltage regulator module 100 is electrically connected to the power supply module 200. The output terminal of the voltage regulator module 100 is electrically connected to the USB interface 300. The output terminal of the voltage regulator module 100 is also electrically connected to the USB interface 300 through a voltage regulating element 500.

[0024] The voltage regulator module 100 is also used to determine whether the USB interface 300 is connected to a load. When the voltage regulator module 100 determines that the USB interface 300 is electrically connected to a load, the voltage regulator module 100 directly outputs the power supply voltage to the USB interface 300, thereby charging the load through the USB interface 300. When the voltage regulator module 100 determines that the USB interface 300 is not connected to a load, the voltage regulator module 100 outputs the power supply voltage from the power module 200 to the USB interface 300 through the voltage regulator element 500. In this way, large current changes at the output terminal of the voltage regulator module 100 can be effectively avoided when the USB interface 300 is not connected to a load, which would cause a voltage drop and affect the stability of the USB voltage regulator circuit 400.

[0025] In this embodiment, the voltage regulator 500 is a Schottky diode. The voltage regulator 500 has a large current capacity and can prevent voltage drop when the USB interface 300 is not connected to a load.

[0026] Please refer to the following: Figure 2 In this embodiment, the power module 200 is used to provide the power supply voltage. The voltage value of the power supply voltage can be 5V.

[0027] The voltage regulator module 100 includes a first filter element 10, an integrated chip 20, a second filter element 30, and a current limiting element 40.

[0028] The first filter element 10 is a capacitor with a capacitance of 10 microfarads (mF). One end of the first filter element 10 is electrically connected to the power module 200 through a voltage-regulating resistor R1. The other end of the first filter element 10 is grounded. The first filter element 10 is used to filter the power supply voltage output by the power module 200 to suppress interference.

[0029] It is understood that in this embodiment, the resistance of the voltage regulator R1 is relatively small, which can be 10 milliohms. It is used to maintain the stability of the circuit and prevent the power module 200 from directly acting on the voltage regulator module 100.

[0030] The integrated chip 20 includes an input terminal VIN, an enable terminal EN, a first output terminal VBUS, a second output terminal VCP, a current limiting terminal ILM, a filter terminal CAP, and a ground terminal GND. It can be understood that in this embodiment, the first output terminal VBUS and the second output terminal VCP are the output terminals of the voltage regulator module 100. Specifically, the first output terminal VBUS is directly electrically connected to the USB interface 300. The second output terminal VCP is electrically connected to the USB interface 300 through the voltage regulator component 500.

[0031] Specifically, the input terminal VIN is electrically connected between the voltage regulating resistor R1 and the first filter element 10. The first output terminal VBUS is directly electrically connected to the USB interface 300. The second output terminal VCP is electrically connected to the anode of the voltage regulating element 500. The cathode of the voltage regulating element 500 is also directly electrically connected to the USB interface 300. Alternatively, the voltage regulating element 500 is positioned between the first output terminal VBUS and the second output terminal VCP. The current limiting terminal ILM is grounded through the current limiting element 40. The filter terminal CAP is grounded through the second filter element 30. The ground terminal GND is grounded. The enable terminal EN is used to receive a control signal to control the conduction or cutoff of electronic components within the integrated chip 20.

[0032] In this embodiment, the second filter element 30 is a capacitor with a capacitance of 1 nanofarad (nF). The second filter element 30 is used to filter the power supply voltage output from the integrated chip 20 to suppress signal interference. The current-limiting element 40 is a resistor with a resistance of 16 kΩ. The current-limiting element 40 is used to prevent excessive current within the integrated chip 20, which could burn out the integrated chip 20.

[0033] In this embodiment, the voltage regulator module 100 further includes a control unit 50. The control unit 50 is electrically connected to the USB interface 300. The control unit 50 is used to detect whether a load is connected to the USB interface 300. The control unit 50 is also electrically connected to the enable terminal EN of the integrated chip 20. The control unit 50 is used to output the control signal, such as a first level signal or a second level signal, according to the detection result, and then control the conduction or cutoff of the electronic components in the integrated chip 20 through the enable terminal EN.

[0034] Specifically, in this embodiment, when the control unit 50 detects that a load is connected to the USB interface 300, the control unit 50 outputs a first-level signal to the enable terminal EN to control the electronic components in the integrated chip 20 to conduct, thereby outputting a power supply voltage through the first output terminal VBUS to charge the load through the USB interface 300. When the control unit 50 detects that no load is connected to the USB interface 300, the control unit 50 outputs a second-level signal to the enable terminal EN to control the electronic components in the integrated chip 20 to cut off, thereby outputting a power supply voltage to the USB interface 300 through the second output terminal VCP and the voltage regulator 500 to prevent voltage drop.

[0035] It is understood that in one embodiment, the first level signal is a high level signal and the second level signal is a low level signal.

[0036] It is understood that in this embodiment, the voltage regulator module 100 further includes a protection element 60. In this embodiment, the protection element 60 can be a diode, which is used to prevent inversion. The cathode of the protection element 60 is electrically connected between the USB interface 300, the cathode of the voltage regulator element 500, and the first output terminal VBUS, and the anode of the protection element 60 is grounded.

[0037] Please refer to the following: Figure 3 , Figure 3 This is a schematic diagram of the internal circuit of the integrated chip 20. The integrated chip 20 includes a first electronic switch Q1, a second electronic switch Q2, a third electronic switch Q3, a voltage regulator 21, and an operational comparator 22.

[0038] The first terminal of the first electronic switch Q1 is electrically connected to the input terminal VIN and the anode of the voltage regulator 21. The cathode of the voltage regulator 21 is electrically connected to the inverting input terminal of the operational comparator 22. In this embodiment, the voltage regulator 21 can be an ammeter, used to maintain a constant voltage of 20mV.

[0039] The second terminal of the first electronic switch Q1 is electrically connected to the enable terminal EN, and is then electrically connected to the control unit 50 via the enable terminal EN. The third terminal of the first electronic switch Q1 is electrically connected to the second output terminal VCP, the anode of the voltage regulator 500, and the third terminal of the second electronic switch Q2.

[0040] The first terminal of the second electronic switch Q2 is electrically connected to the first output terminal VBUS, the cathode of the voltage regulator 500, and the positive input terminal of the operational comparator 22. The second terminal of the second electronic switch Q2 is electrically connected to the enable terminal EN and the first terminal of the third electronic switch Q3. The second terminal of the third electronic switch Q3 is electrically connected to the output terminal of the operational comparator 22. The third terminal of the third electronic switch Q3 is electrically connected to the ground terminal GND of the integrated chip 20 for grounding.

[0041] In this embodiment, the first electronic switch Q1, the second electronic switch Q2, and the third electronic switch Q3 are all P-type MOSFETs, and their on-state voltage is 35mV. The first terminal of the first electronic switch Q1, the first terminal of the second electronic switch Q2, and the first terminal of the third electronic switch Q3 are the drains. The second terminals of the first electronic switch Q1, the second electronic switch Q2, and the third electronic switch Q3 are the gates. The third terminals of the first electronic switch Q1, the second electronic switch Q2, and the third electronic switch Q3 are the sources.

[0042] It is understood that in other embodiments, the first electronic switch Q1, the second electronic switch Q2, and the third electronic switch Q3 are not limited to P-type MOS transistors, and can also be other types of electronic components.

[0043] It is understood that the integrated chip 20 also includes a first diode D1 and a second diode D2. The cathode of the first diode D1 is electrically connected to the input terminal VIN of the integrated chip 20, the first terminal of the first electronic switch Q1, and the anode of the voltage regulator 21. The anode of the first diode D1 is electrically connected to the second output terminal VCP of the integrated chip 20, the anode of the voltage regulator 500, and the anode of the second diode D2. The cathode of the second diode D2 is electrically connected to the first output terminal VBUS of the integrated chip 20, the cathode of the voltage regulator 500, and the positive input terminal of the operational comparator 22.

[0044] In this embodiment, the first diode D1 and the second diode D2 are used to protect the first electronic switch Q1 and the second electronic switch Q2 to prevent them from being upside down.

[0045] In this embodiment, when the voltage at the positive input terminal of the operational comparator 22 is greater than the voltage at its negative input terminal, for example, greater than 4.98V, the operational comparator 22 outputs a high voltage, thereby turning on the third electronic switch Q3. When the voltage at the positive input terminal of the operational comparator 22 is less than the voltage at its negative input terminal, the operational comparator 22 outputs a low voltage, causing the third electronic switch Q3 to turn off.

[0046] In this embodiment, when the control unit 50 detects that the USB interface 300 is electrically connected to a load, the control unit 50 outputs a high-level signal to the integrated chip 20 through the enable terminal EN, so that the first electronic switch Q1 and the second electronic switch Q2 inside the chip are turned on. Thus, the power supply voltage of the power module 200 is output to the first output terminal VBUS through the turned-on first electronic switch Q1 and second electronic switch Q2, and then directly output to the USB interface 300 through the first output terminal VBUS to charge the load.

[0047] In this embodiment, when the control unit 50 detects that the USB interface 300 is not connected to the load or that the current of the USB interface 300 suddenly becomes 0, the control unit 50 outputs a low-level signal to the integrated chip 20 through the enable terminal EN. At this time, due to the decrease in current, the voltage recovers quickly, and the voltage at the positive input terminal of the operational comparator 22 is greater than 4.98V, causing the operational comparator 22 to output a high voltage to control the third electronic switch Q3 to conduct, the first electronic switch Q1 to conduct, and the second electronic switch Q2 to be turned off. The power supply voltage of the power module 200 is output to the USB interface 300 via the conducted first electronic switch Q1, the VCP, and the voltage regulator 500. This effectively avoids the voltage drop that occurs when the current in the USB voltage regulator circuit 400 changes drastically.

[0048] It is understood that in this embodiment, the first electronic switch Q1 is always on.

[0049] It is understood that in this embodiment, the resistance of the voltage regulator 500 is very small, while the current is very large. Therefore, when no load is connected, the current changes significantly, flowing directly through the voltage regulator 500 and not through the second electronic switch Q2. In this embodiment, the forward voltage of the voltage regulator 500 is very small, at 0.2V.

[0050] In this embodiment, when no load is connected, the first electronic switch Q1 is always on, and its on-state voltage is very small and negligible. Therefore, the voltage at the second output terminal VCP of the integrated chip 20 is almost equal to the voltage at the input terminal VIN. Therefore, the voltage of the USB interface 300 can be the difference between the second output terminal VCP of the integrated chip and the voltage regulator 500, i.e., 4.8V. Therefore, in this embodiment, the difference in the USB voltage regulator circuit 400 design exceeds the protocol-specified design requirement of greater than 4.75V, and the USB voltage regulator circuit 400 can be applied in industrial applications.

[0051] It is understood that in this embodiment, the power supply voltage output by the power module 200 can be appropriately adjusted so that the input terminal VIN receives a suitable power supply voltage, and then the USB interface 300 outputs a stable 5V voltage to charge the load.

[0052] This application adds a voltage regulator 500 between the voltage regulator module 100 and the USB interface 300, which can effectively stabilize the circuit when the current in the USB voltage regulator circuit 400 changes instantaneously, thereby ensuring a more stable and reliable output power supply voltage.

[0053] The above embodiments are merely illustrative of the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to the preferred embodiments above, those skilled in the art should understand that modifications or equivalent substitutions to the technical solutions of the present invention should not depart from the spirit and scope of the present invention. Those skilled in the art can also make other changes within the spirit of the present invention and use them in the design of the present invention, as long as they do not deviate from the technical effects of the present invention. These changes made according to the spirit of the present invention should all be included within the scope of protection claimed by the present invention.

Claims

1. A USB voltage regulator circuit, characterized in that: The USB voltage regulator circuit includes a power module, a voltage regulator module, and a voltage regulator element. The power module provides power voltage. The input terminal of the voltage regulator module is electrically connected to the power module, and the output terminal of the voltage regulator module is electrically connected to a USB interface. The output terminal of the voltage regulator module is also electrically connected to the USB interface through the voltage regulator element. When a load is connected to the USB interface, the voltage regulator module directly outputs the power voltage to the USB interface. When no load is connected to the USB interface, the voltage regulator module outputs the power voltage to the USB interface through the voltage regulator element. The voltage regulator module includes an integrated chip, which includes an input terminal, a first output terminal, a second output terminal, an enable terminal, a first electronic switch, and a second electronic switch. The first terminal of the first electronic switch is electrically connected to the input terminal of the integrated chip, the second terminal of the first electronic switch is electrically connected to the enable terminal, the third terminal of the first electronic switch is electrically connected to the second output terminal, one end of the voltage regulator element, and the third terminal of the second electronic switch, the first terminal of the second electronic switch is electrically connected to the first output terminal and the other end of the voltage regulator element, and the second terminal of the second electronic switch is electrically connected to the enable terminal.

2. The USB voltage regulator circuit as described in claim 1, characterized in that: The voltage regulator is a Schottky diode.

3. The USB voltage regulator circuit as described in claim 1, characterized in that: The voltage regulator module includes a first filter element and a second filter element. One end of the first filter element is electrically connected to the power module and the integrated chip, and the other end of the first filter element is grounded. One end of the second filter element is electrically connected to the integrated chip, and the other end of the second filter element is grounded.

4. The USB voltage regulator circuit as described in claim 3, characterized in that: The integrated chip also includes a filter terminal. The input terminal of the integrated chip is electrically connected between the power module and the first filter element. The first output terminal is directly electrically connected to the USB interface. The second output terminal is electrically connected to the USB interface through the voltage regulator element. The filter terminal is grounded through the second filter element.

5. The USB voltage regulator circuit as described in claim 4, characterized in that: The voltage regulator module also includes a control unit electrically connected to the enable terminal. The control unit is used to detect whether the USB interface is connected to a load. When the control unit detects that the USB interface is connected to a load, the control unit outputs a first level signal to the enable terminal to control the integrated chip to output the power supply voltage to the USB interface through the first output terminal. When the control unit detects that the USB interface is not connected to a load, the control unit outputs a second level signal to the enable terminal to control the integrated chip to output the power supply voltage to the USB interface through the second output terminal and the voltage regulator element.

6. The USB voltage regulator circuit as described in claim 4, characterized in that: The voltage regulator module also includes a protection element. One end of the protection element is electrically connected between the USB interface, one end of the voltage regulator element, and the first output terminal, and the other end of the protection element is grounded. The protection element is used to prevent inversion.

7. The USB voltage regulator circuit as described in claim 1, characterized in that: The integrated chip also includes a third electronic switch, an operational comparator, and a voltage regulator. The first terminal of the third electronic switch is electrically connected to the enable terminal and the second terminal of the second electronic switch. The third terminal of the third electronic switch is grounded. The second terminal of the third electronic switch is electrically connected to the output terminal of the operational comparator. The positive input terminal of the operational comparator is electrically connected to the first terminal of the second electronic switch, the first output terminal, and the other end of the voltage regulator. The inverting input terminal of the operational comparator is electrically connected to the input terminal of the integrated chip through the voltage regulator.

8. The USB voltage regulator circuit as described in claim 7, characterized in that: The integrated chip further includes a first diode and a second diode. The cathode of the first diode is electrically connected to the input terminal of the integrated chip, the first terminal of the first electronic switch, and the anode of the voltage regulator. The anode of the first diode is electrically connected to the second output terminal of the integrated chip, one end of the voltage regulator element, and the anode of the second diode. The cathode of the second diode is electrically connected to the first output terminal of the integrated chip, the cathode of the voltage regulator element, and the positive input terminal of the operational comparator. The first diode and the second diode are used to protect the first electronic switch and the second electronic switch to prevent them from being reversed.

9. The USB voltage regulator circuit as described in claim 7, characterized in that: The first electronic switch, the second electronic switch, and the third electronic switch are P-type MOS transistors with a turn-on voltage of 35mV.

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