Control circuit capable of safely improving DC output voltage

Abstract

The invention discloses a control circuit capable of safely improving DC output voltage. The control circuit comprises an AC-DC controller, a control module and a voltage boosting module. The voltage boosting module can fail when the control module receives the turn-off signal; or, the voltage boosting module can take effect when the control module receives the starting signal so as to increase the output voltage; the architecture can be added on the basis of a mature scheme of the existing AC-DC controller, so that the maximum output voltage can be safely and effectively improved, and the time for re-verifying the scheme is shortened; the withstand voltage of the secondary sampling PIN of the AC-DC controller does not need to be improved through redesign, so that the time for redesign and verification of the AC-DC controller is saved, and the cost is reduced; whether the lifting circuit is started or not is controlled through the protocol controller, so that only the upper limit of the output voltage of the AC-DC controller can be improved, and the lower limit of the output voltage is not influenced.

Description

Technical Field

[0001] The present invention relates to the field, and particularly relates to a control circuit that can safely increase the DC output voltage. Background Art

[0002] In recent years, smart devices have been rapidly popularized, and devices with fast charging functions can increase the charging speed by 2-3 times. To meet the growing high-power demand, the PD3.1 protocol of the USB Implementers Forum can support voltages up to 48V. However, the sampling pin of the voltage loop on the secondary side of the IC of some AC-DC controllers cannot withstand the 48V high-voltage output. Secondly, existing AC-DC controllers all output a fixed voltage, and then use a DC-DC buck circuit to control and convert the fixed voltage into an adjustable voltage lower than the fixed voltage. The highest voltage output by this kind of circuit is limited by the AC-DC controller and can only output up to the maximum output voltage of the AC-DC controller, which cannot meet the demand for higher output voltages.

[0003] Therefore, there is an urgent need for a control circuit that can safely increase the DC output voltage to solve the above problems. Summary of the Invention

[0004] The present invention aims to at least solve one of the technical problems existing in the prior art. For this purpose, the present invention provides a control circuit that can safely increase the DC output voltage.

[0005] An embodiment of the present invention solves the technical problem by adopting the following technical solution: A control circuit that can safely increase the DC output voltage, including an AC-DC controller, a control module, and a voltage boosting module;

[0006] The AC-DC controller is connected to the voltage boosting module;

[0007] The control module is connected to the voltage boosting module and is used to receive a turn-off signal or a turn-on signal;

[0008] The voltage boosting module can be invalidated when the control module receives a turn-off signal; or, the voltage boosting module can become effective when the control module receives a turn-on signal to increase the output voltage.

[0009] As one of the preferred embodiments of the present invention, the control module includes MOS transistors M1-M2 and resistors R1-R2. The gate of MOS transistor M1 is connected to the protocol controller. The drain of MOS transistor M1 is connected to the gate of MOS transistor M2 and one end of resistor R2 through resistor R1. The source of MOS transistor M1 is connected to the GND terminal. The source of MOS transistor M2 is connected to the other end of resistor R2 and the voltage boosting module respectively. The drain of MOS transistor M2 is connected to the voltage boosting module.

[0010] As one of the preferred embodiments of the present invention, the voltage boosting module includes resistors R3-R4, capacitors C1-C2, and a reference voltage chip D1. One end of resistor R3 is connected to the control module, one end of capacitor C1, one end of capacitor C2, and the output terminal of the reference voltage chip D1 respectively. The other end of resistor R3 is connected to the other end of capacitor C1, one end of resistor R4, and the control terminal of the reference voltage chip D1 respectively. The other end of resistor R4 is connected to the control module, the input terminal of the reference voltage chip D1, the other end of capacitor C2, and the AC-DC controller respectively.

[0011] As one of the preferred embodiments of the present invention, a control circuit for safely increasing the DC output voltage further includes a resistor R5. One end of resistor R5 is connected to the control module, one end of resistor R3, and one end of capacitor C2 respectively. The other end of resistor R5 is connected to one end of capacitor C1 and the output terminal of the reference voltage chip D1 respectively.

[0012] As one of the preferred embodiments of the present invention, a control circuit for safely increasing the DC output voltage further includes a protocol controller connected to the AC-DC controller and the control module. The protocol controller is used to control the output voltage of the AC-DC controller and send a shutdown signal or an enable signal to the control module.

[0013] Advantages of the present invention:

[0014] 1. It is possible to add this architecture on the basis of the existing mature solution of the AC-DC controller, so that it can safely and effectively increase the maximum output voltage, and reduce the time required to re-verify the solution;

[0015] 2. There is no need to re-design to increase the withstand voltage of the secondary sampling PIN of the AC-DC controller, saving the time for re-designing and verifying the AC-DC controller and reducing the cost;

[0016] 3. By controlling whether the boosting circuit is turned on through the protocol controller, it is possible to only increase the upper limit of the output voltage of the AC-DC controller without affecting the lower limit of the output voltage. Description of the drawings

[0017] The above and / or additional aspects and advantages of the present invention will become apparent and easy to understand from the description of the embodiments in conjunction with the following drawings, where:

[0018] Figure 1 It is a principle block diagram of a control circuit for safely increasing the DC output voltage;

[0019] Figure 2 It is a circuit schematic diagram of a control circuit for safely increasing the DC output voltage. Detailed implementation manners

[0020] This section will describe in detail the specific embodiments of the present invention. The preferred embodiments of the present invention are shown in the accompanying drawings. The function of the accompanying drawings is to supplement the description in the text part of the specification, enabling people to intuitively and vividly understand each technical feature and the overall technical solution of the present invention. However, it should not be construed as a limitation on the protection scope of the present invention.

[0021] In the description of the present invention, the meaning of "a plurality of" is more than two. Understandings such as "greater than", "less than", and "exceeding" do not include the present number, and understandings such as "above", "below", and "within" include the present number. If there is a description of "first" and "second", it is only for the purpose of distinguishing technical features and cannot be construed as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features or implicitly indicating the sequence relationship of the indicated technical features.

[0022] In the description of the present invention, it should be understood that for the orientation description, such as the orientation or positional relationship indicated by "upper", "lower", "front", "rear", "left", "right", etc., is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the indicated device or element must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation on the present invention.

[0023] In the present invention, unless otherwise clearly defined, terms such as "set", "installed", and "connected" should be understood in a broad sense. For example, they can be directly connected, or indirectly connected through an intermediate medium; they can be fixedly connected, or detachably connected, or integrally formed; they can be mechanically connected; they can be the communication inside two elements or the interaction relationship between two elements. Those skilled in the art can reasonably determine the specific meanings of the above terms in the present invention in combination with the specific content of the technical solution.

[0024] Refer to Figures 1 to 2 , a control circuit that can safely increase the DC output voltage, including an AC-DC controller 20, a control module 30, and a voltage boosting module 40;

[0025] The AC-DC controller 20 is connected to the voltage boosting module 40;

[0026] The control module 30 is connected to the voltage boosting module 40 and is used to receive a turn-off signal or a turn-on signal;

[0027] The voltage boosting module 40 can be invalid when the control module 30 receives a turn-off signal; or, the voltage boosting module 40 can be effective when the control module 30 receives a turn-on signal to increase the output voltage.

[0028] In the present invention, the control module 30 is used to control whether the voltage boosting module 40 becomes effective; the voltage boosting module 40 is used to boost a fixed voltage; the AC-DC controller 20 is used to output a voltage; in some embodiments, it further includes a protocol controller 10 connected to the AC-DC controller 20 and the control module 30. The protocol controller 10 is used to control the output voltage of the AC-DC controller 20 and send a turn-off signal or an on signal to the control module 30. The protocol controller 10 communicates according to the protocol, determines how much voltage needs to be output, controls the AC-DC controller 20 to output the corresponding voltage. At this time, the protocol control gives a low level to make the voltage boosting module 40 ineffective; when the voltage exceeding the maximum voltage that the AC-DC controller 20 can output is required, while adjusting the AC-DC controller 20 to the maximum output voltage, the voltage boosting is controlled to boost the output voltage to the required value of the protocol. Specifically:

[0029] ① Refer to Figure 2 , as a preferred embodiment of the control module 30, the control module 30 includes MOS transistors M1-M2 and resistors R1-R2. The gate of the MOS transistor M1 is connected to the protocol controller 10. The drain of the MOS transistor M1 is connected to the gate of the MOS transistor M2 and one end of the resistor R2 through the resistor R1 respectively. The source of the MOS transistor M1 is connected to the GND terminal. The source of the MOS transistor M2 is connected to the other end of the resistor R2 and the voltage boosting module 40 respectively. The drain of the MOS transistor M2 is connected to the voltage boosting module 40.

[0030] According to the communication between the protocol controller 10 and the protocol, it is judged whether the voltage to be output needs to turn on the voltage boost; specifically, when it is not necessary to turn on, when the protocol controller 10 sends an on signal (low-level signal, in some embodiments, the MOS transistor M1 uses an N-channel MOSFET, and it enters the conduction state when a high level is input to its gate) to the control module 30, in the low-level state given by the MOS transistor M1, the MOS transistor M2 is default in the conduction state. At this time, part of the voltage boosting module 40 will be short-circuited to make it ineffective; when it is necessary to turn on, a high level is given to the gate of the MOS transistor M1 to make it conductive. At this time, the gate of the MOS transistor M2 is connected to the GND terminal. At this time, the V gs <0 of the MOS transistor M2 makes the MOS transistor M2 turn off. At this time, part of the voltage boosting module 40 comes into play; among them, both the MOS transistor M1 and the MOS transistor M2 are depletion-type N-channel MOSFETs.

[0031] ② Refer to Figure 2, as a preferred embodiment of the voltage boosting module 40, the voltage boosting module 40 includes resistors R3 - R4, capacitors C1 - C2, and a reference voltage chip D1. One end of resistor R3 is respectively connected to the control module 30, one end of capacitor C1, one end of capacitor C2, and the output terminal of the reference voltage chip D1. The other end of resistor R3 is respectively connected to the other end of capacitor C1, one end of resistor R4, and the control terminal of the reference voltage chip D1. The other end of resistor R4 is respectively connected to the control module 30, the input terminal of the reference voltage chip D1, the other end of capacitor C2, and the AC - DC controller 20.

[0032] The reference voltage chip D1 is a precision programmable reference voltage chip. With the voltage division of resistor R3 and resistor R4, by adjusting the resistance values of the voltage - dividing resistors R3 and R4, the boosted voltage of the output voltage can be adjusted. The calculation formula is as follows: Vo = ((1 + R3 / R4)*Vref)+Vout, where Vref is the reference voltage of the reference voltage chip D1, and Vout is the original output voltage. In a further embodiment, it further includes a resistor R5. One end of resistor R5 is respectively connected to the control module 30, one end of resistor R3, and one end of capacitor C2. The other end of resistor R5 is respectively connected to one end of capacitor C1 and the output terminal of the reference voltage chip D1. Resistor R5 is a current - limiting resistor, which can avoid excessive large current when the voltage difference is too large.

[0033] ③ The advantages of the present invention are as follows: 1. It is possible to add this architecture on the basis of the mature solution of the existing AC - DC controller, enabling it to safely and effectively increase the maximum output voltage and reduce the time required for re - verifying the solution. 2. For the AC - DC controller, the sampled voltage and the withstand voltage value of the PINs in contact with the output generally do not exceed the output voltage of the AC - DC controller by much. After using this architecture, the output voltage that the relevant PINs are in contact with is the voltage before boosting, which will not cause the problem of insufficient withstand voltage of the PINs on the secondary side of the AC - DC controller, and can work normally without being affected. There is no need to re - design to increase the withstand voltage of the secondary - side sampling PINs of the AC - DC controller, saving the time for re - designing and verifying the AC - DC controller and reducing the cost. 3. By controlling whether the boosting circuit is turned on through the protocol controller, it is possible to only increase the upper limit of the output voltage of the AC - DC controller without affecting the lower limit of the output voltage.

[0034] Of course, the present invention is not limited to the above - mentioned embodiments. Those skilled in the art can make equivalent deformations or substitutions without departing from the spirit of the present invention, and these equivalent deformations and substitutions are all included in the scope defined by the claims of this application.

Claims

1. A control circuit for safely increasing a DC output voltage, characterized in that: It includes an AC-DC controller (20), a control module (30) and a voltage raising module (40); The AC-DC controller (20) is connected to the voltage raising module (40); The control module (30) is connected to the voltage raising module (40) and is used to receive a shutdown signal or a start signal; The voltage raising module (40) may be disabled when the control module (30) receives a shutdown signal; or, the voltage raising module (40) may be enabled when the control module (30) receives a start signal to increase the output voltage.

2. A control circuit capable of safely increasing a DC output voltage according to claim 1, characterized in that: The control module (30) comprises MOS tubes M1-M2 and resistors R1-R2, the gate of the MOS tube M1 is connected to the protocol controller (10), the drain of the MOS tube M1 is respectively connected to the gate of the MOS tube M2 and one end of the resistor R2 via the resistor R1, the source of the MOS tube M1 is connected to the GND end, the source of the MOS tube M2 is respectively connected to the other end of the resistor R2 and the voltage raising module (40), and the drain of the MOS tube M2 is connected to the voltage raising module (40).

3. A control circuit capable of safely increasing a DC output voltage according to claim 1, characterized in that: The voltage raising module (40) comprises resistors R3-R4, capacitors C1-C2 and a reference voltage chip D1, one end of the resistor R3 is respectively connected to the control module (30), one end of the capacitor C1, one end of the capacitor C2 and the output end of the reference voltage chip D1, the other end of the resistor R3 is respectively connected to the other end of the capacitor C1, one end of the resistor R4 and the control end of the reference voltage chip D1, and the other end of the resistor R4 is respectively connected to the control module (30), the input end of the reference voltage chip D1, the other end of the capacitor C2 and the AC-DC controller (20).

4. A control circuit capable of safely increasing a DC output voltage according to claim 3, characterized in that: It also includes a resistor R5, one end of which is respectively connected to the control module (30), one end of the resistor R3 and one end of the capacitor C2, and the other end of the resistor R5 is respectively connected to one end of the capacitor C1 and the output end of the reference voltage chip D1.

5. A control circuit capable of safely increasing a DC output voltage according to claim 1, characterized in that: It also includes a protocol controller (10) connected to the AC-DC controller (20) and the control module (30), wherein the protocol controller (10) is used to control the output voltage of the AC-DC controller (20) and to send the shutdown signal or the startup signal to the control module (30).

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