Power supply protection circuit and display device

Abstract

The invention discloses a power supply protection circuit and a display device. The power supply protection circuit comprises a switch control module and a discharge module, the input end of the switch control module is connected with the input port, the output end of the switch control module is connected with the output port, and the first end of the switch control module is grounded; the control end of the discharging module is connected with the second end of the switch control module, the first end of the discharging module is connected with the output port, and the second end of the discharging module is grounded; the switch control module is used for conducting the input port and the output port when the input voltage is greater than a preset value; and the switch control module is also used for controlling the discharge module to be conducted when the input voltage is smaller than or equal to a preset value. According to the power supply protection circuit provided by the invention, the on-off of the discharge module is controlled through the switch control module, so that normal shutdown can be ensured after shutdown and restart when the input voltage is powered down to a certain range, normal work can be ensured when the input voltage returns to a normal value again, and a display device can perform normal display.

Description

Technical Field

[0001] The present invention relates to the technical field of power supply protection, and in particular to a power supply protection circuit and a display device. Background Art

[0002] In the related art, when the input voltage of the power management chip (Power IC) of the display device drops to a certain range (such as between 2.0V-2.3V), the reset function of the power management chip will be triggered, and the frame start signal (STV), clock signal (CLK) and other signals in the power management chip will be pulled up to a high level (VGH). The high level is instantly pulled down, causing the input voltage to be pulled down, triggering the undervoltage lockout function of the power management chip, and the input voltage drops and locks to the undervoltage lockout falling threshold UVLO_F (such as 1.8V), causing the power management chip to shut down, and the various outputs of the power management chip are turned off. When the various outputs of the power management chip are turned off, the load becomes lighter, so that the input voltage is raised, and the undervoltage lockout function of the power management chip is triggered again, and the input voltage rises to the undervoltage lockout rising threshold UVLO_R (such as 2.3V). When the power management chip is restarted, it is measured that the power management chip has output except VGL (low level), triggering the channel output abnormal protection, causing the chip to shut down abnormally. When the input voltage returns to normal value, the display device cannot display normally.

[0003] The power management chip of the existing display device shuts down abnormally when the input voltage drops within a certain range, and fails to display normally when the input voltage returns to a normal value, which has become a technical problem that needs to be solved urgently in the industry. Summary of the invention

[0004] The present invention provides a power protection circuit and a display device to solve the problem that the existing display device shuts down abnormally when the input voltage drops to a certain range, and cannot display normally when the input voltage returns to a normal value.

[0005] According to one aspect of the present invention, there is provided a power protection circuit, comprising: a switch control module and a discharge module;

[0006] The input end of the switch control module is connected to the input port, the output end of the switch control module is connected to the output port, and the first end of the switch control module is grounded;

[0007] The control end of the discharge module is connected to the second end of the switch control module, the first end of the discharge module is connected to the output port, and the second end of the discharge module is grounded;

[0008] The switch control module is used to connect the input port and the output port when the input voltage is greater than a preset value;

[0009] The switch control module is further configured to control the discharge module to turn on when the input voltage is less than or equal to the preset value.

[0010] Optionally, the switch control module includes: a voltage dividing unit, an impedance unit, a first switch unit, and a second switch unit;

[0011] The first end of the voltage dividing unit is connected to the input port, the second end of the voltage dividing unit is grounded, and the voltage dividing output end of the voltage dividing unit is connected to the control end of the first switch unit; the voltage dividing unit is configured to output a first voltage dividing signal when the input voltage is greater than the preset value; and output a second voltage dividing signal when the input voltage is less than or equal to the preset value;

[0012] The first end of the first switch unit is connected to the control end of the second switch unit, and the second end of the first switch unit is grounded; the first switch unit turns on in response to the first voltage dividing signal and outputs a first level from its first end, and turns off in response to the second voltage dividing signal;

[0013] The first end of the second switch unit is connected to the input port, and the second end of the second switch unit is connected to the output port; the second switch unit turns on in response to the first level and turns off in response to a second level, where the second level is logically opposite to the first level;

[0014] The first end of the impedance unit is connected to the input port, and the second end of the impedance unit is connected to the second end of the first switch unit;

[0015] The discharge module is connected to the first end of the first switch unit, and the discharge module is configured to turn off in response to the first level and turn on in response to the second level.

[0016] Optionally, the voltage dividing unit includes: a first resistor and a second resistor;

[0017] The first end of the first resistor is connected to the input port, the second end of the first resistor is connected to the first end of the second resistor, and the second end of the second resistor is grounded.

[0018] Optionally, the switch control module further includes: a third resistor and / or a fourth resistor;

[0019] The first end of the third resistor is connected to the second end of the first switch unit, and the second end of the third resistor is grounded;

[0020] The first end of the fourth resistor is connected to the control end of the second switch unit, and the second end of the fourth resistor is connected to the first end of the first switch unit.

[0021] Optionally, the discharging module includes: a third switching unit;

[0022] The control terminal of the third switching unit is connected to the control terminal of the second switching unit. The first terminal of the third switching unit is connected to the output port, and the second terminal of the third switching unit is grounded.

[0023] Optionally, the discharging module further includes: a fifth resistor;

[0024] The first terminal of the fifth resistor is connected to the second terminal of the third switching unit, and the second terminal of the fifth resistor is grounded.

[0025] Optionally, the power protection circuit further includes: a first filtering module;

[0026] The first terminal of the first filtering module is connected to the input port, the second terminal of the first filtering module is connected to the input terminal of the switch control module, and the third terminal of the first filtering module is grounded.

[0027] Optionally, the power protection circuit further includes: a second filtering module;

[0028] The first terminal of the second filtering module is connected to the output terminal of the switch control module, the second terminal of the second filtering module is connected to the output port, and the third terminal of the second filtering module is grounded.

[0029] Optionally, the first resistor and / or the second resistor is an adjustable resistor.

[0030] According to another aspect of the present invention, a display device is provided, including the above-mentioned power protection circuit.

[0031] The technical solution of the embodiment of the present invention, by setting the switch control module and the discharging module, the switch control module is used to directly conduct the input port and the output port when the input voltage is higher than the preset value, so that the power management chip directly receives the input voltage. When the input voltage is less than or equal to the preset value, the switch control module controls the discharging module to conduct. Since one end of the discharging module is grounded, the input voltage is close to 0 at this time, causing the power management chip to shut down. When the input voltage returns to normal, the switch control module controls the discharging module to turn off, the input port is connected to the output port, and the power management chip receives the normal input voltage. The power protection circuit of the embodiment of the present invention, by setting the switch control module and the discharging module, and controlling the conduction and turn-off of the discharging module through the switch control module, can enable the power management chip to shut down normally when the input voltage drops, and when the input voltage returns to normal, the power management chip can start up normally, and the display device can display normally, effectively solving the problems existing in the prior art.

[0032] It should be understood that the content described in this section is not intended to identify the key or important features of the embodiments of the present invention, nor is it used to limit the scope of the present invention. Other features of the present invention will become readily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0034] Figure 1 It is a schematic structural diagram of a power supply circuit in the prior art;

[0035] Figure 2 It is a schematic structural diagram of a power supply protection circuit provided by an embodiment of the present invention;

[0036] Figure 3 It is a schematic structural diagram of another power supply protection circuit provided by an embodiment of the present invention;

[0037] Figure 4 It is a schematic structural diagram of another power supply protection circuit provided by an embodiment of the present invention;

[0038] Figure 5 It is a schematic structural diagram of another power supply protection circuit provided by an embodiment of the present invention;

[0039] Figure 6 It is a schematic structural diagram of another power supply protection circuit provided by an embodiment of the present invention;

[0040] Figure 7 It is a schematic structural diagram of another power supply protection circuit provided by an embodiment of the present invention;

[0041] Figure 8 It is a schematic structural diagram of another power supply protection circuit provided by an embodiment of the present invention;

[0042] Figure 9 It is a schematic structural diagram of another power supply protection circuit provided by an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0043] To enable those skilled in the art to better understand the solution of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0044] It should be noted that the terms "first", "second", etc. in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and do not necessarily need to be used to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of the present invention described here can be implemented in an order other than those illustrated or described here. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device including a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0045] Figure 1 It is a schematic structural diagram of a power supply circuit in the prior art. As described in the background art, refer to Figure 1 , when the input voltage (i.e., the voltage on the input port Vin) of the existing power supply circuit drops to a certain range (such as 2.0V - 2.3V), it will trigger the under-voltage lockout function of the power management chip (Power IC), resulting in the input voltage being pulled down to the corresponding under-voltage lockout drop threshold of the power management chip, causing the power management chip to shut down. When the outputs of all channels of the power management chip are turned off, the input voltage will be pulled up and trigger the under-voltage lockout function of the power management chip. The input voltage is pulled up to the under-voltage lockout rise threshold, and the power management chip will restart. Since the power management chip has outputs for all voltages except the low level (VGL), triggering the output abnormal protection of the channel causes the power management chip to shut down abnormally. When the input voltage returns to the normal value, the display device cannot display normally, which does not meet the requirements and seriously affects the user experience.

[0046] To solve the above technical problems, the present invention provides a power supply protection circuit, Figure 2 It is a schematic structural diagram of a power supply protection circuit provided by an embodiment of the present invention. Refer to Figure 2, the power protection circuit 100 includes a switch control module 10 and a discharge module 20. The input end of the switch control module 10 is connected to the input port Vin, the output end of the switch control module 10 is connected to the output port Vout, and the first end of the switch control module 10 is grounded; the control end of the discharge module 20 is connected to the second end of the switch control module 10, the first end of the discharge module 20 is connected to the output port Vout, and the second end of the discharge module 20 is grounded; the switch control module 10 is configured to turn on the input port Vin and the output port Vout when the input voltage is greater than a preset value; the switch control module 10 is further configured to control the discharge module 20 to turn on when the input voltage is less than or equal to the preset value.

[0047] Specifically, the present invention provides a power protection circuit 100. The power protection circuit 100 is connected to the input pin of the power management chip, which can ensure that the power management chip can be shut down normally after restarting when the input voltage drops, and the power management chip can work normally when the input voltage returns to the working voltage, and the display device can display normally. The power protection circuit 100 includes a switch control module 10 and a discharge module 20. The input end of the switch control module 10 is connected to the input voltage input port Vin, and the output end of the switch control module 10 is connected to the output port Vout, that is, connected to the input pin of the power management chip. The first end of the switch control module 10 is grounded, the second end of the switch control module 10 is connected to the control end of the discharge module 20, the first end of the discharge module 20 is connected to the output port Vout, that is, connected to the input end of the power management chip, and the second end of the discharge module 20 is grounded. The switch control module 10 is mainly used to receive the input voltage and determine the working states of itself and the discharge module according to the amplitude of the input voltage. When the amplitude of the input voltage is greater than the preset value, the switch control module 10 directly turns on the input port Vin and the output port Vout, and the input port Vin directly supplies power to the power management chip. When the amplitude of the input voltage is less than or equal to the preset value, the switch control module 10 controls the discharge module 20 to turn on. Since the second end of the discharge module 20 is grounded, it is equivalent to that the output end is grounded through the discharge module 20, the input pin of the power management chip is grounded, and the input voltage of the power management chip is approximately equal to 0, triggering the shutdown voltage of the power management chip, and the power management chip shuts down.

[0048] Specifically, when the input voltage is greater than the preset value, that is, when the input voltage is normal, the input voltage does not need to be processed by the power protection circuit. The switch control module 20 controls the input port Vin of the power protection circuit 100 to be directly connected to the output port Vout, and the power management chip can receive the normal input voltage. When the output voltage drops, if the input voltage drops below or equal to the preset value after the input voltage drops, and within a certain range of the input voltage drop (such as 2.0V - 2.3V), if the input voltage is directly transmitted to the power management chip at this time, it will trigger the under-voltage lockout function of the power management chip, causing the power management chip to shut down abnormally. After the abnormal shutdown, the load becomes lighter and the input voltage is pulled up. Since the trigger channel output abnormal protection causes the display device to fail to display normally. At this time, if the input voltage drops below or equal to the preset value after the input voltage drops, the discharge module 20 is controlled to conduct through the switch control module 10. One end of the discharge module 20 is grounded. At this time, the input voltage is close to 0. At this time, the input voltage is less than the under-voltage lockout drop threshold UVLO_F (1.8V), and the power management chip shuts down directly. After the power management chip shuts down, since its input pin is grounded through the discharge module 20, the input voltage will not be pulled up, and the power management chip remains in the shutdown state. When the input voltage resumes and is higher than the preset value, the switch control module 10 controls the discharge module 20 to disconnect and controls the input port Vin to be directly connected to the output port Vout, and the power management chip receives the input voltage and works normally. Among them, the present invention does not limit the preset value, which can be set according to the actual situation. Exemplarily, the preset value of the present invention can be taken as 2.3V. When the input voltage is greater than 2.3V, the input pin of the power management chip directly receives the normal input voltage. When the input voltage is less than or equal to 2.3V, the power management chip is grounded through the discharge module 20, so that the input voltage of the power management chip is lower than the under-voltage lockout drop threshold UVLO_F, and the power management chip shuts down normally.

[0049] The power protection circuit 100 provided by the embodiment of the present invention, by setting the switch control module 10 and the discharge module 20, the switch control module 10 is used to directly conduct the input port Vin and the output port Vout when the input voltage is higher than the preset value, so that the power management chip directly receives the input voltage. When the input voltage is less than or equal to the preset value, it controls the discharge module 20 to conduct. Since one end of the discharge module 20 is grounded, at this time the input voltage is close to 0, and the power management chip shuts down. When the input voltage returns to normal, the switch control module 10 controls the discharge module 20 to turn off, the input port Vin is connected to the output port Vout, and the power management chip receives the normal input voltage. The power protection circuit 100 of the embodiment of the present invention, by setting the switch control module 10 and the discharge module 20, and controlling the conduction and turn-off of the discharge module 20 through the switch control module 10, can enable the power management chip to shut down normally when the input voltage drops, and when the input voltage returns to normal, the power management chip can start up normally, and the display device can display normally, effectively solving the problems existing in the prior art.

[0050] Optionally, Figure 3 It is a schematic structural diagram of another power protection circuit provided by the embodiment of the present invention. On the basis of the above embodiments, refer to Figure 3 . The switch control module 10 includes a voltage dividing unit 11, an impedance unit 12, a first switch unit 13 and a second switch unit 14. The first end of the voltage dividing unit 11 is connected to the input port Vin, the second end of the voltage dividing unit 11 is grounded, and the voltage dividing output end of the voltage dividing unit 11 is connected to the control end of the first switch unit 13; the voltage dividing unit 11 is used to output a first voltage dividing signal when the input voltage is greater than the preset value, and output a second voltage dividing signal when the input voltage is less than or equal to the preset value; the first end of the first switch unit 13 is connected to the control end of the second switch unit 14, and the second end of the first switch unit 13 is grounded; the first switch unit 13 conducts in response to the first voltage dividing signal and outputs a first level from its first end, and turns off in response to the second voltage dividing signal; the first end of the second switch unit 14 is connected to the input port Vin, and the second end of the second switch unit 14 is connected to the output port Vout; the second switch unit 14 conducts in response to the first level and turns off in response to the second level, where the second level is opposite in logic to the first level; the first end of the impedance unit 12 is connected to the input port Vin, and the second end of the impedance unit 12 is connected to the second end of the first switch unit 13; the discharge module 20 is connected to the first end of the first switch unit 13, and the discharge module 20 is used to turn off in response to the first level and conduct in response to the second level.

[0051] Specifically, the voltage dividing unit 11 is mainly used to output a first divided voltage signal at the divided voltage output end when the input voltage is greater than a preset value. After the voltage dividing unit 11 outputs the first divided voltage signal, the first switch unit 13 responds to the first divided voltage signal. The first switch unit 13 is turned on under the action of the first divided voltage signal, and the first end of the first switch unit 13 outputs a first level. The control end of the second switch unit 14 responds to the first level, and the second switch unit 14 is turned on under the action of the first level. After receiving the first level, the discharge module 20 is turned off under the action of the first level. When the input voltage is greater than the preset value, under the action of the voltage dividing unit 11, the first switch unit 11 and the second switch unit 13 are turned on, the discharge module 20 is turned off, and the input port Vin of the power protection circuit 100 is directly connected to the output port Vout under the action of the first switch unit 11, the second switch unit 13, and the third switch unit 14, and the input pin of the power management chip receives a normal input voltage. The voltage dividing unit 11 is also used to output a second divided voltage signal at the divided voltage output end when the input voltage is less than or equal to the preset value. After the control end of the first switch unit 11 receives the second divided voltage signal, the first switch unit 11 is turned off under the action of the second divided voltage signal. The second end of the impedance unit 12 is connected to the control end of the second switch 14. When the input voltage is less than or equal to the preset value, the first switch unit 13 is turned off. Under the action of the impedance unit 12, the control end of the second switch 14 receives a second level, and the second switch unit 14 is turned off under the action of the second level. The control end of the discharge module 20 can also receive the second level, and the discharge module 20 is turned on under the action of the second level. At this time, the input port Vin is grounded through the voltage dividing unit 11, the output port Vout is grounded through the discharge module 20, and the input voltage is almost 0, enabling the power management chip to shut down normally. Among them, the second level is logically opposite to the first level. Under the action of the first level, the second switch unit 14 is turned on and the discharge module 20 is turned off. Under the action of the second level, the second switch unit 14 is turned off and the discharge module 20 is turned on. When the input voltage is normal, the voltage dividing unit 11 outputs a first divided voltage signal at the output end, the first switch unit 13 and the second switch 14 are turned on, the discharge module 40 is turned off, and the power management chip works normally. Among them, the first divided voltage signal can be a signal greater than the turn-on voltage of the first switch unit 13, and the second divided voltage signal can be a signal less than or equal to the turn-on voltage of the first switch unit 13. When the input voltage is greater than the preset value, the first divided voltage signal output at the output end of the voltage dividing unit 11 is greater than the turn-on voltage of the first switch unit, causing the first switch unit 13 to be turned on. When the input voltage is less than or equal to the preset value, the second divided voltage signal output at the output end of the voltage dividing unit 11 is less than the turn-on voltage of the first switch unit, causing the first switch unit 13 to be turned off.

[0052] Optionally, Figure 4A schematic structural diagram of another power protection circuit provided by an embodiment of the present invention. Based on the above embodiments, refer to Figure 4 . The voltage dividing unit 11 includes a first resistor R1 and a second resistor R2; a first end of the first resistor R1 is connected to the input port Vin, a second end of the first resistor R1 is connected to a first end of the second resistor R2, and a second end of the second resistor R2 is grounded.

[0053] Specifically, the voltage dividing unit 11 includes the first resistor R1 and the second resistor R2 connected in series. When the input voltage is greater than a preset value, after the input voltage is divided by the first resistor R1 and the second resistor R2, the voltage dividing output end of the voltage dividing unit 11 outputs a first divided voltage signal. Under the action of the first divided voltage signal, the first switch unit 13 is turned on, the first switch unit 13 outputs a first level, and under the action of the first level, the second switch unit 14 is turned on, and the discharge module 20 is turned off, so that the power management chip directly receives the input voltage. When the input voltage is not greater than the preset value, under the voltage dividing action of the first resistor R1 and the second resistor R2, the voltage dividing output end of the voltage dividing unit 11 outputs a second divided voltage signal. Under the action of the second divided voltage signal, the first switch unit 13 is turned off, the second switch unit 14 is turned off corresponding to the second level, the discharge module 20 is turned on corresponding to the second level, the input voltage is 0, and the power management chip shuts down. Among them, the first resistor R1 and / or the second resistor R2 is an adjustable resistor. By setting the first resistor R1 and / or the second resistor R2 as an adjustable resistor, the preset value can be set flexibly, and further the application range of the power protection circuit can be wider, and it can adapt to more scenarios. The resistance values of the first resistor R1 and the second resistor R2 are not specifically limited in the present invention and can be set according to actual situations.

[0054] Optionally, Figure 5 A schematic structural diagram of another power protection circuit provided by an embodiment of the present invention. Based on the above embodiments, refer to Figure 5 . The discharge module 20 includes a third switch unit 21; a control end of the third switch unit 21 is connected to a control end of the second switch unit 14, a first end of the third switch unit 21 is connected to the output port Vout, and a second end of the third switch unit 21 is grounded.

[0055] Specifically, the discharge module 20 includes a third switch unit 21. The third switch unit 21 is mainly used to turn off when the input voltage is greater than a preset value. When the control terminal of the third switch unit 21 receives a first level, under the action of the first level, the third switch unit turns off, and the input voltage is directly output to the power management chip through the second switch unit 14. When the input voltage is less than or equal to the preset value, the control terminal of the third switch unit 21 receives a second level. Under the action of the second level, the third switch unit turns on, and the output port Vout is grounded through the third switch unit 21, so that the input voltage is 0. When the input voltage drops to less than or equal to the preset value, the output port Vout is directly grounded, so that the power management chip can be normally powered on and off.

[0056] Optionally, on the basis of the above embodiments, continue to refer to Figure 5 . The discharge module 20 further includes a fifth resistor R5; the first end of the fifth resistor R5 is connected to the second end of the third switch unit 21, and the second end of the fifth resistor R5 is grounded.

[0057] Specifically, by connecting the fifth resistor R5 in series at the second end of the third switch unit 21, the current can be effectively controlled, avoiding electrostatic breakdown of the third switch unit 21, thereby protecting the third switch unit 21. It can also reduce the noise of the third switch unit 21, improve the stability and reliability of the circuit, improve the anti-interference ability of the circuit, and optimize the circuit performance.

[0058] Optionally, Figure 6 is a schematic structural diagram of another power protection circuit provided by an embodiment of the present invention. Figure 7 is a schematic structural diagram of another power protection circuit provided by an embodiment of the present invention. On the basis of the above embodiments, continue to refer to Figure 5 、 Figure 6 and Figure 7 . The switch control module 10 further includes a third resistor R3 and / or a fourth resistor R4; the first end of the third resistor R3 is connected to the second end of the first switch unit 13, and the second end of the third resistor R3 is grounded; the first end of the fourth resistor R4 is connected to the control terminal of the second switch unit 14, and the second end of the fourth resistor R4 is connected to the first end of the first switch unit 13.

[0059] Specifically, the switch control module 10 further includes a third resistor R3 and / or a fourth resistor R4. The third resistor R3 and the first switch unit 13 are connected in series, and the fourth resistor R4 and the second switch unit 14 are connected in series. The third resistor R3 and the fourth resistor R4 can effectively play a current limiting role, thereby protecting the first switch unit 13 and the second switch unit 14, improving the stability and reliability of the power protection circuit, and improving the anti-interference ability of the power protection circuit.

[0060] Optionally,Figure 8 This is a schematic structural diagram of another power protection circuit provided by an embodiment of the present invention. Based on the above embodiments, refer to Figure 8 . The power protection circuit 100 further includes a first filtering module 30; a first end of the first filtering module 30 is connected to the input port Vin, a second end of the first filtering module 30 is connected to an input end of the switch control module 10, and a third end of the first filtering module 30 is grounded.

[0061] Specifically, the power protection circuit 100 further includes a fuse F1, and the first filtering module 30 includes a first capacitor C1, a second capacitor C2, and a third capacitor C3. A first end of the fuse F1 is connected to the input port Vin, and a second end of the fuse F1 is respectively connected to a first end of the first capacitor C1, a first end of the second capacitor C2, and a first end of the third capacitor C3. A second end of the first capacitor C1, a second end of the second capacitor C2, and a second end of the third capacitor C3 are grounded. Arranging the first filtering module 30 at the input port Vin can effectively protect the circuit against overcurrent, and the filtering capacitors can also filter out the noise in the input voltage Vin to ensure that the input voltage is cleaner.

[0062] Optionally, based on the above embodiments, continue to refer to Figure 8 . The power protection circuit 100 further includes a second filtering module 40; a first end of the second filtering module 40 is connected to an output end of the switch control module 10, a second end of the second filtering module 40 is connected to the output port Vout, and a third end of the second filtering module 40 is grounded.

[0063] Specifically, the second filtering module 40 includes a fourth capacitor C4, a fifth capacitor C5, a sixth capacitor C6, and a sixth resistor R6. A first end of the fourth capacitor C4, a first end of the fifth capacitor C5, and a first end of the sixth capacitor C6 are respectively connected to the output end of the switch control module 10. A second end of the fourth capacitor C4, a second end of the fifth capacitor C5, and a second end of the sixth capacitor C6 are grounded. A sixth resistor R6 has a first end respectively connected to the first end of the fourth capacitor C4, the first end of the fifth capacitor C5, and the first end of the sixth capacitor C6, and a second end of the sixth resistor R6 is grounded. Arranging the second filtering module 40 at the output port Vout of the circuit can filter out the ripple of the output voltage and provide a more stable signal.

[0064] Optionally, Figure 9 This is a schematic structural diagram of another power protection circuit provided by an embodiment of the present invention. Based on the above embodiments, refer to Figure 9。The impedance unit may be the seventh resistor R7. The first switching unit 13 may be an NPN transistor Q1. The second unit 14 may be a PNP transistor Q2. The third switching unit 21 may be a MOS transistor Q3. When the input voltage is greater than a preset value, after the input voltage is divided by the first resistor R1 and the second resistor R2, the voltage-dividing output terminal of the voltage-dividing unit 11 outputs a first voltage-dividing signal. The first switching unit 13 is an NPN transistor Q1 and is turned on. The first switching unit 13 outputs a first level. The second switching unit 14 is turned on, and the third switching unit 21 is turned off. The power management chip directly receives the input voltage. When the input voltage is less than or equal to the preset value, after the input voltage is divided by the first resistor R1, the second resistor R2, and the seventh resistor R7, the first switching unit 13 is turned off, the second switching unit 14 is turned off, and the third switching unit 21 is turned on. The input pin of the power management chip is grounded through the third switching unit 21. The input voltage is lower than the undervoltage lockout drop threshold, and the power management chip shuts down normally and can work normally after the input voltage returns to normal.

[0065] The embodiment of the present invention further provides a display device, including the power protection circuit provided in any of the above embodiments. The display device further includes a power management chip, and the power protection circuit is electrically connected to the power management chip. The display device may be a mobile phone, a tablet computer, an MP3, an MP4, a video phone, a personal digital assistant, an in-vehicle display, a smart watch, a smart helmet, or other wearable devices, etc. Since the display device provided by the embodiment of the present invention includes the power protection circuit provided by the embodiment of the present invention, it also has the same beneficial effects and will not be described in detail here.

[0066] Note that the above is only the preferred embodiment of the present invention and the applied technical principle. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described here. Various obvious changes, re-adjustments, and substitutions can be made by those skilled in the art without departing from the protection scope of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments. Without departing from the concept of the present invention, more other equivalent embodiments can be included, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A power protection circuit, characterized in that: include: Switch control module and discharge module; The input end of the switch control module is connected to the input port, the output end of the switch control module is connected to the output port, and the first end of the switch control module is grounded; The control end of the discharge module is connected to the second end of the switch control module, the first end of the discharge module is connected to the output port, and the second end of the discharge module is grounded; The switch control module is used to connect the input port and the output port when the input voltage is greater than a preset value; The switch control module is further used to control the discharge module to be turned on when the input voltage is less than or equal to the preset value.

2. The power protection circuit according to claim 1, characterized in that: The switch control module includes: a voltage dividing unit, an impedance unit, a first switch unit and a second switch unit; The first end of the voltage dividing unit is connected to the input port, the second end of the voltage dividing unit is grounded, and the voltage dividing output end of the voltage dividing unit is connected to the control end of the first switch unit; the voltage dividing unit is used to output a first voltage dividing signal when the input voltage is greater than a preset value; and output a second voltage dividing signal when the input voltage is less than or equal to the preset value; The first end of the first switch unit is connected to the control end of the second switch unit, and the second end of the first switch unit is grounded; the first switch unit is turned on in response to the first voltage division signal and outputs the first level from its first end, and is turned off in response to the second voltage division signal; A first end of the second switch unit is connected to the input port, and a second end of the second switch unit is connected to the output port; the second switch unit is turned on in response to the first level, and is turned off in response to a second level, wherein the second level is logically opposite to the first level; The first end of the impedance unit is connected to the input port, and the second end of the impedance unit is connected to the second end of the first switch unit; The discharge module is connected to the first end of the first switch unit, and is configured to be turned off in response to the first level and turned on in response to the second level.

3. The power protection circuit according to claim 2, characterized in that: The voltage dividing unit comprises: a first resistor and a second resistor; A first end of the first resistor is connected to the input port, a second end of the first resistor is connected to a first end of the second resistor, and a second end of the second resistor is grounded.

4. The power protection circuit according to claim 2, characterized in that: The switch control module further includes: a third resistor and / or a fourth resistor; The first end of the third resistor is connected to the second end of the first switch unit, and the second end of the third resistor is grounded; A first end of the fourth resistor is connected to the control end of the second switch unit, and a second end of the fourth resistor is connected to the first end of the first switch unit.

5. The power protection circuit according to claim 2, characterized in that: The discharge module comprises: a third switch unit; The control end of the third switch unit is connected to the control end of the second switch unit, the first end of the third switch unit is connected to the output port, and the second end of the third switch unit is grounded.

6. The power protection circuit according to claim 5, characterized in that: The discharge module further includes: a fifth resistor; A first end of the fifth resistor is connected to a second end of the third switch unit, and a second end of the fifth resistor is grounded.

7. The power protection circuit according to claim 1, characterized in that: The power protection circuit further includes: a first filtering module; A first end of the first filter module is connected to the input port, a second end of the first filter module is connected to the input end of the switch control module, and a third end of the first filter module is grounded.

8. The power protection circuit according to claim 1, characterized in that: The power protection circuit further includes: a second filtering module; A first end of the second filter module is connected to the output end of the switch control module, a second end of the second filter module is connected to the output port, and a third end of the second filter module is grounded.

9. The power protection circuit according to claim 3, characterized in that: The first resistor and / or the second resistor is an adjustable resistor.

10. A display device, characterized in that: include: The power protection circuit according to any one of claims 1 to 9.

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