阅读说明：本技术 过流保护电路、电源电路和显示装置 (Overcurrent protection circuit, power supply circuit and display device ) 是由 杨勇 于 2021-06-25 设计创作，主要内容包括：本申请涉及一种过流保护电路、电源电路和显示装置,该过流保护电路用于控制电源管理电路的输出电流,包括：第一电阻,第一电阻的第一端和第二端分别接地和电连接于电源管理电路,且流经第一电阻的电流为电源管理电路的输出电流；第二电阻和第三电阻,第二电阻的第一端和第二端分别电连接于第一电阻的第一端和第三电阻的第二端；稳压器,用于控制第三电阻的第一端与第一电阻的第二端之间的电压差为预设值；运放比较器,其第一输入端和第二输入端分别电连接于第一电阻的第二端和第二电阻的第二端,且当第一输入端与第二输入端之间的电压差为正值时,其第二输出端输出控制电信号,以使电源管理电路减小输出电流,从而避免输出功率过大而造成损害。(The application relates to an overcurrent protection circuit, a power supply circuit and a display device, wherein the overcurrent protection circuit is used for controlling the output current of a power supply management circuit and comprises: the first end and the second end of the first resistor are respectively grounded and electrically connected with the power management circuit, and the current flowing through the first resistor is the output current of the power management circuit; the first end and the second end of the second resistor are respectively and electrically connected with the first end of the first resistor and the second end of the third resistor; the voltage stabilizer is used for controlling the voltage difference between the first end of the third resistor and the second end of the first resistor to be a preset value; and when the voltage difference between the first input end and the second input end is a positive value, the second output end outputs a control electric signal so that the power management circuit reduces the output current, thereby avoiding the damage caused by overlarge output power.)

1. An overcurrent protection circuit for controlling the output current of a power management circuit, the overcurrent protection circuit comprising:

the first end of the first resistor is grounded, the second end of the first resistor is electrically connected to the power management circuit, and the current flowing through the first resistor is the output current of the power management circuit;

the first end of the second resistor is electrically connected to the first end of the first resistor, and the second end of the second resistor is electrically connected to the second end of the third resistor;

the voltage stabilizer comprises a first output end, the first output end is electrically connected to the first end of the third resistor, and the voltage stabilizer is used for controlling the voltage difference between the first end of the third resistor and the second end of the first resistor to be a preset value;

the operational amplifier comparator comprises a first input end, a second input end and a second output end, wherein the first input end is electrically connected to the second end of the first resistor, the second input end is electrically connected to the second end of the second resistor, and when the voltage difference between the first input end and the second input end is a positive value, the operational amplifier comparator outputs a control electric signal through the second output end so that the power management circuit reduces the output current.

2. The overcurrent protection circuit of claim 1, wherein the power management circuit comprises a third output terminal and at least one output circuit electrically connected to the third output terminal, a preset voltage is applied to the third output terminal, each output circuit is connected to a corresponding electronic device, the output circuit is configured to provide an operating current to the corresponding electronic device, and the output current of the power management circuit is a sum of the operating currents provided by all the output circuits or the operating current provided by one output circuit.

3. The over-current protection circuit of claim 2, wherein the output current of the power management circuit is the operating current provided by a target output circuit of the at least one output circuit, and the first resistor is connected in series with the electronic device connected to the target output circuit.

4. The over-current protection circuit according to claim 3, further comprising a first control switch, wherein the first control switch, the first resistor and the electronic device connected to the target output circuit are connected in series, and when a voltage difference between the first input terminal and the second input terminal is a positive value, the operational amplifier comparator outputs the control electrical signal to the first control switch through the second output terminal, and the first control switch receives the control electrical signal and is turned off to stop the power supply to the target output circuit.

5. The overcurrent protection circuit of claim 3, wherein the power management circuit further comprises a current output control unit, the current output control unit is electrically connected to the second output terminal of the operational amplifier comparator, and when a voltage difference between the first input terminal and the second input terminal is a positive value, the operational amplifier comparator outputs the control electrical signal to the current output control unit through the second output terminal, and the current output control unit receives the control electrical signal and reduces the working current provided by the target output circuit.

6. The overcurrent protection circuit of claim 2, further comprising:

and the second control switch, the third output end and the at least one output circuit are connected in series, and when the voltage difference between the first input end and the second input end is a positive value, the operational amplifier comparator outputs the control electric signal to the second control switch through the second output end, and the second control switch receives the control electric signal and is disconnected, so that all the output circuits stop supplying power.

7. The overcurrent protection circuit of claim 2, further comprising:

and each third control switch is electrically connected to the corresponding output circuit, and when the voltage difference between the first input end and the second input end is a positive value, the operational amplifier comparator outputs the control electrical signal to the third control switch through the second output end, and the third control switches receive the control electrical signal and are disconnected so as to stop the power supply of the corresponding output circuit.

8. The overcurrent protection circuit of claim 1, wherein the control electrical signal is a high level signal, and when the voltage difference between the first input terminal and the second input terminal is not a positive value, the operational amplifier comparator outputs a low level electrical signal through the second output terminal.

9. A power supply circuit comprising the overcurrent protection circuit as set forth in any one of claims 1 to 8 and a power management circuit, the overcurrent protection circuit being configured to control an output current of the power management circuit.

10. A display device comprising the power supply circuit according to claim 9 and a display panel electrically connected to the power supply circuit, wherein the output current is an operating current supplied from the power management circuit to the display panel.

[ technical field ] A method for producing a semiconductor device

The application relates to the technical field of power supplies, in particular to an overcurrent protection circuit, a power supply circuit and a display device.

[ background of the invention ]

Currently, the input voltage of the display device driving circuit is usually 12V or 24V, and the display panel driving circuit converts the input voltage into each path of voltage required for display of the display panel by using a DC/DC buck-boost circuit.

However, when the display device driving circuit actually works, a situation that the load is increased drastically (for example, a certain output circuit fails, or the forward voltage of the light emitting diode chip is reduced after heating) often occurs, and the occurrence of these situations may increase the input power of the display device driving circuit, and further cause the power supply system to work in an overload state (that is, in an over-power working device), and risks such as heating and burning are likely to occur.

[ summary of the invention ]

The present application is directed to an over-current protection circuit, a power supply circuit and a display device, so as to avoid damage caused by an excessive output power of a power management circuit in a power supply system.

In order to solve the above problem, an embodiment of the present application provides an overcurrent protection circuit, where the overcurrent protection circuit is used to control an output current of a power management circuit, and the overcurrent protection circuit includes: the first end of the first resistor is grounded, the second end of the first resistor is electrically connected to the power management circuit, and the current flowing through the first resistor is the output current of the power management circuit; the first end of the second resistor is electrically connected to the first end of the first resistor, and the second end of the second resistor is electrically connected to the second end of the third resistor; the voltage stabilizer comprises a first output end, the first output end is electrically connected to the first end of the third resistor, and the voltage stabilizer is used for controlling the voltage difference between the first end of the third resistor and the second end of the first resistor to be a preset value; the operational amplifier comparator comprises a first input end, a second input end and a second output end, wherein the first input end is electrically connected to the second end of the first resistor, the second input end is electrically connected to the second end of the second resistor, and when the voltage difference between the first input end and the second input end is a positive value, the operational amplifier comparator outputs a control electric signal through the second output end so that the power management circuit reduces the output current.

The power management circuit comprises a third output end and at least one output circuit electrically connected with the third output end, a preset voltage is applied to the third output end, each output circuit is connected with corresponding electronic equipment, the output circuits are used for providing working current for the corresponding electronic equipment, and the output current of the power management circuit is the sum of the working currents provided by all the output circuits or the working current provided by one output circuit.

The output current of the power management circuit is the working current provided by the target output circuit in the at least one output circuit, and the first resistor is connected in series with the electronic equipment connected to the target output circuit.

The overcurrent protection circuit further comprises a first control switch, the first resistor and the electronic equipment connected to the target output circuit are connected in series, when the voltage difference between the first input end and the second input end is a positive value, the operational amplifier comparator outputs a control electric signal to the first control switch through the second output end, and the first control switch receives the control electric signal and is disconnected, so that the target output circuit stops supplying power.

The power management circuit further comprises a current output control unit, the current output control unit is electrically connected to a second output end of the operational amplifier comparator, when the voltage difference between the first input end and the second input end is a positive value, the operational amplifier comparator outputs a control electric signal to the current output control unit through the second output end, and the current output control unit receives the control electric signal and reduces the working current provided by the target output circuit.

Wherein, overcurrent protection circuit still includes: and the second control switch, the third output end and the at least one output circuit are connected in series, when the voltage difference between the first input end and the second input end is a positive value, the operational amplifier comparator outputs a control electric signal to the second control switch through the second output end, and the second control switch receives the control electric signal and is disconnected so as to stop all the output circuits from supplying power.

Wherein, overcurrent protection circuit still includes: and each third control switch is electrically connected to the corresponding output circuit, and when the voltage difference between the first input end and the second input end is a positive value, the operational amplifier comparator outputs a control electric signal to the third control switch through the second output end, and the third control switch receives the control electric signal and is disconnected so as to stop the power supply of the corresponding output circuit.

The control electrical signal is a high-level signal, and when the voltage difference between the first input end and the second input end is not a positive value, the operational amplifier comparator outputs a low-level electrical signal through the second output end.

In order to solve the above problem, an embodiment of the present application further provides a power supply circuit, where the power supply circuit includes any one of the overcurrent protection circuit and the power management circuit, and the overcurrent protection circuit is configured to control an output current of the power management circuit.

In order to solve the above problem, an embodiment of the present application further provides a display device, where the display device includes the above power supply circuit and a display panel electrically connected to the power supply circuit, and the output current is an operating current provided by the power management circuit to the display panel.

The beneficial effect of this application is: be different from prior art, the overcurrent protection circuit that this application provided for control power management circuit's output current, including first resistance, the second resistance, the third resistance, stabiliser and fortune are put the comparator, can be at the voltage difference between the first input of fortune amplifier comparator and the second input for the positive value, promptly, when power management circuit's output current was too big, control power management circuit reduced output current, thereby under power management circuit's the fixed unchangeable condition of output voltage, can avoid power management circuit to lead to the high temperature and damage because output current is too big.

[ description of the drawings ]

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is a schematic structural diagram of an overcurrent protection circuit provided in an embodiment of the present application;

fig. 2 is another schematic structural diagram of an overcurrent protection circuit provided in an embodiment of the present application;

fig. 3 is another schematic structural diagram of an overcurrent protection circuit provided in an embodiment of the present application;

fig. 4 is another schematic structural diagram of an overcurrent protection circuit provided in an embodiment of the present application;

fig. 5 is another schematic structural diagram of an overcurrent protection circuit provided in an embodiment of the present application;

fig. 6 is another schematic structural diagram of an overcurrent protection circuit provided in an embodiment of the present application;

fig. 7 is another schematic structural diagram of an overcurrent protection circuit provided in an embodiment of the present application;

fig. 8 is another schematic structural diagram of an overcurrent protection circuit according to an embodiment of the present application;

FIG. 9 is a schematic diagram of a power circuit according to an embodiment of the present disclosure;

fig. 10 is a schematic structural diagram of a display device according to an embodiment of the present application.

[ detailed description ] embodiments

The present application will be described in further detail with reference to the following drawings and examples. It is to be noted that the following examples are only illustrative of the present application, and do not limit the scope of the present application. Likewise, the following examples are only some examples and not all examples of the present application, and all other examples obtained by a person of ordinary skill in the art without any inventive step are within the scope of the present application.

Referring to fig. 1, fig. 1 is a schematic structural diagram of an overcurrent protection circuit according to an embodiment of the present disclosure. As shown in fig. 1, the overcurrent protection circuit 10 is electrically connected to the power management circuit 20 for controlling the output current I of the power management circuit 20, and specifically, the overcurrent protection circuit 10 may include a first resistor R1, a second resistor R2, a third resistor R3, a voltage regulator 14, and an operational amplifier comparator 15.

The first end of the first resistor R1 is grounded GND, the second end of the first resistor R1 is electrically connected to the power management circuit 20, and the current flowing through the first resistor R1 is the output current I of the power management circuit 20. A first end of the second resistor R2 is electrically connected to a first end of the first resistor R1, and a second end of the second resistor R2 is electrically connected to a second end of the third resistor R3. The voltage regulator 14 includes a first output terminal 141, the first output terminal 141 is electrically connected to the first terminal of the third resistor R3, and specifically, the voltage regulator 14 is configured to control a voltage difference (V3-V1) between the first terminal of the third resistor R3 and the second terminal of the first resistor R1 to be a predetermined value (e.g., 2.5V). The operational amplifier comparator 15 includes a first input terminal 151, a second input terminal 152 and a second output terminal 153, specifically, the first input terminal 151 is electrically connected to the second terminal of the first resistor R1, the second input terminal 152 is electrically connected to the second terminal of the second resistor R2, and when a voltage difference (V1-V2) between the first input terminal 151 and the second input terminal 152 of the operational amplifier comparator 15 is a positive value, that is, the voltage V1 applied to the first input terminal 151 is greater than the voltage V2 applied to the second input terminal 152, the operational amplifier comparator 15 outputs a control electrical signal through the second output terminal 153, so that the power management circuit 20 reduces the output current I, and the power management circuit 20 is prevented from being damaged due to an excessive output power.

In this embodiment, the output voltage V4 of the power management circuit 20 may be constant, and the output power P corresponding to the power management circuit 20 is (I × V4), that is, when the output voltage V4 is constant, the output power P of the power management circuit 20 is proportional to the output current I.

Specifically, the control electrical signal output by the second output terminal 153 of the operational amplifier comparator 15 may be a high level signal, and when the voltage difference (V1-V2) between the first input terminal 151 and the second input terminal 152 of the operational amplifier comparator 15 is not a positive value, that is, the voltage V1 applied to the first input terminal 151 is not greater than the voltage V2 applied to the second input terminal 152, the operational amplifier comparator 15 outputs a low level electrical signal through the second output terminal 153, and the output current I of the power management circuit 20 is not changed, that is, there is no need to perform over-current or over-power protection on the power management circuit 20. The high level signal may be a logic level "1", and the low level signal may be a logic level "0".

In this embodiment, the calculation formula of the voltage V1 applied to the first input terminal 151 of the operational amplifier comparator 15 may be: v1 ═ I R1; the calculation formula of the voltage V2 applied to the second input terminal 152 of the operational amplifier comparator 15 may be: v2 ═ V3 × R2/(R3+ R2). Based on this, the output voltage between the first input terminal 151 and the second input terminal 152 of the operational amplifier comparator 15 can be obtainedThe voltage difference (V1-V2) is calculated as: (V1-V2) ═ I R1R 3-_△V × R2)/(R3+ R2). Wherein R1, R2 and R3 are resistance values of a first resistor R1, a second resistor R2 and a third resistor R3 respectively,_△v is equal to (V3-V1), i.e.,_△v is used to represent the voltage difference (V3-V1) between the first end of the third resistor R3 and the second end of the first resistor R1, which is a predetermined value (e.g., 2.5V) and is fixed.

Specifically, when the voltage difference (V1-V2) between the first input terminal 151 and the second input terminal 152 of the operational amplifier comparator 15 is not a positive value, i.e., (V1-V2) is greater than zero, the calculation formula of (V1-V2) shows that (I × R1 × R3-_△V R2) is greater than zero, and it can be obtained that I is greater than_△V R2/R1R 3. By analogy, when the voltage difference (V1-V2) between the first input terminal 151 and the second input terminal 152 of the operational amplifier comparator 15 is not positive, I is not greater than_△V*R2/R1*R3。

As can be seen from the above, the present invention,_△v R2/R1R 3 is the maximum output current allowed to be output by the power management circuit 20, and V4R_△V × R2/R1 × R3 is the maximum output power allowed to be outputted by the power management circuit 20. When the output current I of the power management circuit 20 is greater than the maximum output current, the operational amplifier comparator 15 outputs a control electrical signal through the second output terminal 153, so that the power management circuit 20 reduces the output current I, thereby achieving the purpose of reducing the output power P. When the output current I of the power management circuit 20 is not greater than the maximum output current, the operational amplifier comparator 15 does not output the control electrical signal through the second output terminal 153, and the output current I of the power management circuit 20 is not changed by the corresponding overcurrent protection circuit 10.

It will be appreciated that the above description has been made with_△V R2/R1R 3 is an overcurrent protection point of the overcurrent protection circuit 10, and in specific implementation, the overcurrent protection point of the overcurrent protection circuit 10 can be flexibly set by adjusting the resistance values of the first resistor R1, the second resistor R2 and the third resistor R3, so that the requirements of different power management circuits 20 on overcurrent protection nodes can be met, and the practicability is improved.

The first resistor R1, the second resistor R2, and the third resistor R3 may be constant resistors or adjustable resistors. In this way, the adjustment of the overcurrent protection point of the overcurrent protection circuit 10 can be realized by replacing the first resistor R1, the second resistor R2 and/or the third resistor R3 in the overcurrent protection circuit 10, or changing the resistance value of the first resistor R1, the second resistor R2 and/or the third resistor R3 in the overcurrent protection circuit 10.

For example, the resistances of the first resistor R1, the second resistor R2, and the third resistor R3 may be 0.10 Ω, 10K Ω, and 25K Ω, respectively, and the voltage difference between the first end of the third resistor R3 and the second end of the first resistor R1_△V is 2.5V, the overcurrent protection point of the overcurrent protection circuit 10 for the power management circuit 20_△V R2/R1R 3 is 10A. Further, if the output voltage V4 of the power management circuit 20 is constant and 12V, the over-current protection circuit 10 protects the power management circuit 20 from the over-current protection point V4 ×_△V R2/R1R 3 was 120W.

In one embodiment, in order to reduce the amount of calculation, the voltage V1 applied to the first input terminal 151 of the operational amplifier comparator 15 may be defined as zero, that is, V1 is equal to 0V. Accordingly, a voltage difference between the first terminal of the third resistor R3 and the second terminal of the first resistor R1_△V is V3, the voltage difference (V1-V2) between the first input terminal 151 and the second input terminal 152 of the operational amplifier comparator 15 is-V2, and V2 (V3R 2-I R1R 3)/(R3+ R2) is only required to detect whether the voltage V2 applied to the second input terminal 152 is less than 0V.

Specifically, the operational amplifier comparator 15 may monitor the voltage V2 applied to the second input terminal 152 in real time, and output a control electrical signal through the second output terminal 153 when the voltage V2 applied to the second input terminal 152 is less than 0V, so that the power management circuit 20 performs overcurrent protection.

In an embodiment, as shown in fig. 1, fig. 2 and fig. 3, the power management circuit 20 may include a third output terminal 21, a preset voltage is applied to the third output terminal 21, and the preset voltage is the output voltage V4 of the power management circuit 20. Specifically, the preset voltage may be a fixed voltage, and may be any positive voltage such as 12V or 24V.

Specifically, the power management circuit 20 may be configured to provide an operating current I1/I2 to at least one electronic device 30, and as shown in fig. 2, the output current I of the power management circuit 20 may be an operating current I1 provided by the power management circuit 20 to one of the at least one electronic device 30, or, as shown in fig. 3, may be a sum of the operating currents provided by the power management circuit 20 to the electronic devices 30 (I1+ I2). As described above, the overcurrent protection circuit 10 can be used not only to control the sum of the operating currents supplied from the power management circuit 20 to the electronic devices 30, but also to control the sum of the operating currents supplied from the power management circuit 20 to one of the electronic devices 30.

In a specific implementation, as shown in fig. 2 and fig. 3, the power management circuit 20 may further include at least one output circuit 22 electrically connected to the third output terminal 21, each output circuit 22 is connected to a corresponding electronic device 30, and each output circuit 22 is configured to provide an operating current I1/I2 to the corresponding electronic device 30. Accordingly, the output current I of the power management circuit 20 is the sum (I1+ I2) of the operating currents provided by all the output circuits 22, or the operating current I1 provided by one of the output circuits 22 in the at least one output circuit 22.

In some embodiments, as shown in fig. 2, the output current 1 of the power management circuit 20 may be an operating current I1 provided by a target output circuit of the at least one output circuit 22, and the first resistor R1 may be connected in series with the electronic device 30 connected to the target output circuit, so as to ensure that the current flowing through the first resistor R1 is the output current I of the power management circuit 20.

In an embodiment, as shown in fig. 4, the over-current protection circuit 10 may further include a first control switch K1, the first control switch K1, the first resistor R1 and the electronic device 30 connected to the target output circuit are connected in series, and when a voltage difference (V1-V2) between the first input terminal 151 and the second input terminal 152 of the operational amplifier comparator 15 is a positive value, the operational amplifier comparator 15 outputs a control electrical signal to the first control switch K1 through the second output terminal 153, and then the first control switch K1 receives the control electrical signal and turns off to stop the power supply to the target output circuit. In this way, when the output current I of the power management circuit 20 is greater than the overcurrent protection point of the overcurrent protection circuit 10, the overcurrent protection circuit 10 can set the output current I1/I2 of any one of the output circuits 22 of the power management circuit 20 to zero.

Specifically, the first control switch K1 may include a logic control unit and a switch unit. The logic control unit is configured to receive a high level signal (that is, the control electrical signal) sent by the operational amplifier comparator 15, and send a conducting signal to the switch unit according to the received high level signal, and is configured to receive a low level signal sent by the operational amplifier comparator 15, and send a disconnecting signal to the switch unit according to the received low level signal.

In an embodiment, the switching unit may be a field effect transistor, for example, a MOS transistor. The logic control unit may be connected to a gate of the field effect transistor. The conducting signal may be a voltage signal, and a voltage value corresponding to the voltage signal may be greater than a threshold voltage of the field effect transistor. The turn-off signal may also be a voltage signal, and a voltage value corresponding to the voltage signal is not greater than a threshold voltage of the field effect transistor.

In some alternative embodiments, the first control switch K1 may be disposed in the power management circuit 20 instead of the first control switch K1 disposed in the over-current protection circuit 10. In a specific embodiment, the first control switch K1 provided in the power management circuit 20 may be connected in series to the target output circuit.

In another embodiment, as shown in fig. 5, the power management circuit 20 may further include a first current output control unit 23, where the first current output control unit 23 is electrically connected to the second output terminal 153 of the operational amplifier comparator 15. When the voltage difference (V1-V2) between the first input terminal 151 and the second input terminal 152 of the operational amplifier comparator 15 is a positive value, the operational amplifier comparator 15 outputs a control electrical signal to the first current output control unit 23 through the second output terminal 153, and then the first current output control unit 23 receives the control electrical signal and reduces the working current I1 provided by the target output circuit according to the control electrical signal. In this way, when the output current I of the power management circuit 20 is greater than the overcurrent protection point of the overcurrent protection circuit 10, the overcurrent protection circuit 10 can reduce the output current I1/I2 of any one of the output circuits 22 of the power management circuit 20, thereby achieving the purpose of reducing the output current I or the output power P of the power management circuit 20.

Specifically, the first current output control unit 23 may increase the resistance in the target output circuit to achieve the purpose of reducing the operating current I1 provided by the target output circuit. Also, in some alternative embodiments, the first current output control unit 23 may be disposed in the overcurrent protection circuit 10 instead of the first current output control unit 23 disposed in the power management circuit 20. In concrete implementation, the first current output control unit 23 provided in the overcurrent protection circuit 10 is also connected in series to the target output circuit.

In some alternative embodiments, as shown in fig. 6, the over-current protection circuit 10 may further include a second control switch K2, where the second control switch K2, the third output terminal 21 and the at least one output circuit 22 are connected in series, and when a voltage difference (V1-V2) between the first input terminal 151 and the second input terminal 152 of the operational amplifier comparator 15 is a positive value, the operational amplifier comparator 15 outputs a control electrical signal to the second control switch K2 through the second output terminal 153, and then the second control switch K2 receives the control electrical signal and turns off, so that all the output circuits 20 of the power management circuit 20 stop supplying power, thereby reducing the output current I or the output power P of the power management circuit 20 to zero.

The second control switch K2 and the first control switch K1 may have the same structure and working principle, and the specific structure and working principle corresponding to the second control switch K2 may be the same as those of the first control switch K1, so that the details are not repeated herein. In addition, in some alternative embodiments, the second control switch K2 may also be disposed in the power management circuit 20 instead of the second control switch K2 disposed in the over-current protection circuit 10. In a specific implementation, the second control switch K2 provided in the power management circuit 20 may be connected in series with the third output terminal 21 and the at least one output circuit 22. In this way, when the output current I of the power management circuit 20 is greater than the overcurrent protection point of the overcurrent protection circuit 10, the overcurrent protection circuit 10 can make the sum (I1+ I2) of the output currents of the output circuits 22 of the power management circuit 20 zero.

In other alternative embodiments, as shown in fig. 7, the over-current protection circuit 10 may further include at least one third control switch K1, each third control switch K1 may be electrically connected to the corresponding output circuit 22, and when the voltage difference (V1-V2) between the first input terminal 151 and the second input terminal 152 of the operational amplifier comparator 15 is positive, the operational amplifier comparator 15 outputs a control electrical signal to the third control switch K3 through the second output terminal 153, and then the third control switch K3 receives the control electrical signal and turns off, so as to stop supplying power to the corresponding output circuit 22.

The third control switch K3 and the first control switch K1 may have the same structure and operation principle, and the specific structure and operation principle corresponding to the third control switch K3 may be the same as those of the first control switch K1, which is not repeated herein. In addition, in some alternative embodiments, the third control switch K3 may be disposed in the power management circuit 20 instead of the third control switch K3 disposed in the over-current protection circuit 10. In a specific implementation, the third control switch K3 provided in the power management circuit 20 may be electrically connected to the corresponding output circuit 22. In this way, when the output current I of the power management circuit 20 is greater than the overcurrent protection point of the overcurrent protection circuit 10, the overcurrent protection circuit 10 can make the output current I1/I2 of at least one output circuit 22 of the power management circuit 20 zero.

In the above embodiment, part or all of the at least one third control switch K3, the third control switch K3 may be replaced by a second current output control unit (not shown), so that when the output current I of the power management circuit 20 is greater than the overcurrent protection point of the overcurrent protection circuit 10, the overcurrent protection circuit 10 can reduce the output current I1/I2 of the at least one output circuit 22 of the power management circuit 20.

The second current output control unit and the first current output control unit 23 may have the same structure and working principle, and the specific structure and working principle corresponding to the second current output control unit may be the same as those of the first current output control unit 23, so that the details are not repeated herein.

In the above embodiment, the specific structures of the voltage regulator 14 and the operational amplifier comparator 15 may be as shown in fig. 8, wherein the voltage regulator 14 may be an AZ431 voltage regulator, and the operational amplifier comparator 15 may be a simple voltage comparator.

Be different from prior art, the overcurrent protection circuit in this embodiment for control power management circuit's output current, including first resistance, second resistance, third resistance, stabiliser and operational amplifier comparator, can be at the voltage difference between the first input and the second input of operational amplifier comparator for the positive value, promptly, when power management circuit's output current was too big, control power management circuit reduced output current, thereby under power management circuit's the fixed unchangeable condition of output voltage, can avoid power management circuit to lead to the high temperature and damage because output current is too big.

Referring to fig. 9, fig. 9 is a schematic structural diagram of a power circuit according to an embodiment of the present disclosure. As shown in fig. 9, the power supply circuit 80 includes an overcurrent protection circuit 81 and a power management circuit 82 in any of the above embodiments, wherein the overcurrent protection circuit 81 is used for controlling the output current of the power management circuit 82.

Specifically, the overcurrent protection circuit 81 may include: the first end of the first resistor is grounded, the second end of the first resistor is electrically connected to the power management circuit, and the current flowing through the first resistor is the output current of the power management circuit; the first end of the second resistor is electrically connected to the first end of the first resistor, and the second end of the second resistor is electrically connected to the second end of the third resistor; the voltage stabilizer comprises a first output end, the first output end is electrically connected to the first end of the third resistor, and the voltage stabilizer is used for controlling the voltage difference between the first end of the third resistor and the second end of the first resistor to be a preset value; the operational amplifier comparator comprises a first input end, a second input end and a second output end, wherein the first input end is electrically connected to the second end of the first resistor, the second input end is electrically connected to the second end of the second resistor, and when the voltage difference between the first input end and the second input end is a positive value, the operational amplifier comparator outputs a control electric signal through the second output end so that the power management circuit reduces the output current.

Specifically, the power management circuit 82 may include a third output terminal and at least one output circuit electrically connected to the third output terminal, a preset voltage is applied to the third output terminal, each output circuit is connected to a corresponding electronic device, the output circuit is configured to provide an operating current to the corresponding electronic device, and the output current of the power management circuit is a sum of the operating currents provided by all the output circuits or an operating current provided by one output circuit. The electronic device may be embodied as a display device. In addition, in the present embodiment, the specific structure and the operation principle of the power management circuit 82 may refer to the specific structure and the operation principle of the power management circuit 20 in the foregoing embodiment, and therefore, the detailed description is omitted here.

Different from the prior art, the power supply circuit in the embodiment can avoid the damage of the power supply management circuit due to overhigh temperature caused by overlarge output current under the condition that the output voltage of the power supply management circuit is fixed and unchanged.

Referring to fig. 10, fig. 10 is a schematic structural diagram of a display device according to an embodiment of the present application. As shown in fig. 10, the display device 90 includes a power supply circuit 91 in any of the embodiments described above, and a display panel 92 electrically connected to the power supply circuit. The display device 70 may be any product or component with a display function, such as a liquid crystal panel, an OLED panel, a liquid crystal television, a tablet computer, a liquid crystal display, or a digital photo frame.

Specifically, the power supply circuit 91 may include the overcurrent protection circuit and the power management circuit in any of the embodiments, where the overcurrent protection circuit is configured to control an output current of the power management circuit, and specifically may include: the first end of the first resistor is grounded, the second end of the first resistor is electrically connected to the power management circuit, and the current flowing through the first resistor is the output current of the power management circuit; the first end of the second resistor is electrically connected to the first end of the first resistor, and the second end of the second resistor is electrically connected to the second end of the third resistor; the voltage stabilizer comprises a first output end, the first output end is electrically connected to the first end of the third resistor, and the voltage stabilizer is used for controlling the voltage difference between the first end of the third resistor and the second end of the first resistor to be a preset value; the operational amplifier comparator comprises a first input end, a second input end and a second output end, wherein the first input end is electrically connected to the second end of the first resistor, the second input end is electrically connected to the second end of the second resistor, and when the voltage difference between the first input end and the second input end is a positive value, the operational amplifier comparator outputs a control electric signal through the second output end so that the power management circuit reduces the output current.

Accordingly, the output current of the power management circuit may be the operating current provided by the power management circuit to the display panel 92.

Different from the prior art, the display device in the embodiment can avoid the damage of the power management circuit due to overhigh temperature caused by overlarge output current under the condition that the output voltage of the power management circuit is fixed and unchanged.

The above description is only exemplary of the present application and should not be taken as limiting the present application, as any modification, equivalent replacement, or improvement made within the spirit and principle of the present application should be included in the protection scope of the present application.