Gating circuit and display panel

Abstract

The invention discloses a gating circuit and a display panel. In the gating circuit, a power supply line is connected with a power supply end, and the power supply end provides power supply voltage for the power supply line; one end of the step-down switch module is connected with a power supply line and the other end is connected with a step-down circuit; one end of the boost switch module is connected with a power supply line, and the other end is connected with a boost circuit; one end of the comparison output module is connected with a power supply line and the other end is connected with an output circuit; the comparison output module is used for receiving the lower limit voltage and the upper limit voltage, when the power supply voltage is between the lower limit voltage and the upper limit voltage, the comparison output module is switched on, and the step-down switch module and the step-up switch module are switched off; when the power supply voltage is smaller than the lower limit voltage, the boost switch module is switched on, and the buck switch module and the comparison output module are switched off; when the power supply voltage is larger than the upper limit voltage, the step-down switch module is switched on, and the step-up switch module and the comparison output module are switched off. According to the technical scheme, the influence of the external environment temperature on the resistance of the metal wire can be effectively reduced.

Description

Technical Field

[0001] The present application belongs to the field of display technology, and in particular relates to a gating circuit and a display panel. Background Art

[0002] The switching voltage required by the display is generally converted by the internal circuit of the control chip and input into the panel. However, since the data lines connecting the panel are usually metal traces, the resistance of the metal traces will change when affected by the external temperature. When the resistance of the metal traces is greatly affected by the external temperature, it will directly affect the size of the switching voltage reaching the panel, resulting in abnormal display of the display screen, or even failure to turn on normally. Summary of the invention

[0003] The purpose of the present application is to provide a gating circuit that can effectively reduce the influence of the external ambient temperature on the resistance of the metal wiring, ensure the accuracy of the switching voltage within the surface, and reduce the situation where the screen display is abnormal and the display screen cannot be turned on normally.

[0004] Other features and advantages of the present application will become apparent from the following detailed description, or may be learned in part by the practice of the present application.

[0005] According to one aspect of an embodiment of the present application, the present application provides a gating circuit, the gating circuit comprising:

[0006] A power supply line, the power supply line is connected to a power supply terminal, and the power supply terminal provides a power supply voltage to the power supply line;

[0007] A step-down switch module, one end of which is connected to the power supply line, and the other end of which is used to connect to a step-down circuit;

[0008] A boost switch module, one end of which is connected to the power supply line, and the other end of which is used to connect to a boost circuit;

[0009] A comparison output module, one end of which is connected to the power supply line, and the other end of which is used to connect to an output circuit;

[0010] The comparison output module is used to receive a lower limit voltage and an upper limit voltage, the upper limit voltage is greater than the lower limit voltage, and when the supply voltage is between the lower limit voltage and the upper limit voltage, the comparison output module is turned on, and the buck switch module and the boost switch module are both turned off;

[0011] The supply voltage is less than the lower limit voltage, the boost switch module is turned on, and the buck switch module and the comparison output module are both turned off;

[0012] When the supply voltage is greater than the upper limit voltage, the step-down switch module is turned on, and the step-up switch module and the comparison output module are both turned off.

[0013] In one aspect, the step-down switch module includes a first voltage-stabilizing diode and a first transistor, the emitter of the first transistor is connected to the power supply line, the emitter of the first transistor is connected to the step-down circuit, the anode of the first voltage-stabilizing diode is connected to the base of the first transistor, the cathode of the first voltage-stabilizing diode is connected to the first ground wire, one end of the first ground wire is connected to the power supply line, and the other end of the first ground wire is grounded.

[0014] In one aspect, the step-down switch module further includes a first current limiting resistor and a first voltage dividing resistor, and the first current limiting resistor and the first voltage dividing resistor are arranged on the first ground line;

[0015] The cathode of the first voltage-limiting diode is connected to the first node of the first grounding line, one end of the first current-limiting resistor is connected to the first node, and the other end of the first current-limiting resistor is grounded;

[0016] One end of the first voltage-dividing resistor is connected to the first node, and the other end of the first voltage-dividing resistor is connected to the power supply line.

[0017] In one aspect, the lower limit voltage is a threshold voltage of the first Zener diode.

[0018] In one aspect, the boost switch module includes a first gating submodule and a second gating submodule;

[0019] The threshold voltage of the first gating submodule is the upper limit voltage, and the second gating submodule has a conduction voltage, which is less than the lower limit voltage;

[0020] One end of the first gating submodule is connected to the power supply line, and the other end of the first gating submodule is grounded;

[0021] One end of the second gating submodule is connected to the power supply line, the other end of the second gating submodule is connected to the boost circuit, and the second gating submodule is connected to the first gating submodule;

[0022] When the supply voltage is greater than the turn-on voltage and less than the lower limit voltage, the second gating submodule is turned on, and the step-down switch module and the comparison output module are both turned off.

[0023] In one aspect, the first gating submodule includes: a second voltage stabilizing diode and a second triode, and the second gating submodule includes a third voltage stabilizing diode and a response switch;

[0024] The emitter of the second transistor is connected to the power supply line, the collector of the second transistor is grounded, the anode of the second voltage zener diode is connected to the collector of the second transistor, the cathode of the second voltage zener diode is connected to the power supply line, and the base of the second transistor is connected to the line between the cathode of the second voltage zener diode and the power supply line;

[0025] The input end of the response switch is connected to the power supply line, the output end of the response switch is connected to the boost circuit, the anode of the third voltage regulator diode is connected to the collector of the second transistor, the cathode of the third voltage regulator diode is connected to the power supply line, and the control end of the response switch is connected to the anode of the third voltage regulator diode.

[0026] In one aspect, the first gating submodule includes a second current limiting resistor, a third current limiting resistor, and a second voltage dividing resistor, and the second gating submodule includes a fourth current limiting resistor;

[0027] One end of the second current limiting resistor is connected to the cathode of the second voltage stabilizing diode, and the other end of the second current limiting resistor is connected to the power supply line;

[0028] One end of the second voltage-dividing resistor is connected to the base of the second transistor, and the other end of the second voltage-dividing resistor is connected to the line between the second current-limiting resistor and the second voltage-stabilizing diode;

[0029] One end of the third current limiting resistor is connected to the collector of the second transistor, and the other end of the third current limiting resistor is grounded;

[0030] One end of the fourth current limiting resistor is connected to the anode of the third voltage stabilizing diode and the control end of the response switch, and the other end of the fourth current limiting resistor is grounded.

[0031] In one aspect, the upper limit voltage is a threshold voltage of the second Zener diode.

[0032] In one aspect, the comparison output module includes a first operational amplifier and a second operational amplifier, the first operational amplifier having a first non-inverting input terminal and a first inverting input terminal, and the second operational amplifier having a second non-inverting input terminal and a second inverting input terminal;

[0033] The first non-inverting input terminal of the first operational amplifier is used to receive the lower limit voltage, the second inverting input terminal of the second operational amplifier is used to receive the upper limit voltage, and the first inverting input terminal of the first operational amplifier and the second non-inverting input terminal of the second operational amplifier are both connected to the power supply line;

[0034] The comparison output module also includes a third transistor, the output end of the first operational amplifier and the output end of the second operational amplifier are both connected to the base of the third transistor, the collector of the third transistor is connected to the power supply line, the emitter of the third transistor is grounded, and the output circuit is connected to the collector of the third transistor.

[0035] In addition, in order to solve the above problems, the present application also provides a display panel, which includes a control chip and a gating circuit as described above, the control chip is connected to the power supply end of the gating circuit, and the control chip provides the power supply voltage to the power supply line.

[0036] In the present application, an upper limit voltage and a lower limit voltage are provided. When the supply voltage provided by the power supply line is between the upper limit voltage and the lower limit voltage, it indicates that the supply voltage is less affected by the ambient temperature. At this time, the comparison output module is turned on, and the supply voltage is directly output through the output circuit of the comparison output module. When the supply voltage is less than the lower limit voltage, it indicates that the ambient temperature affects the voltage of the power supply line, resulting in a decrease in the supply voltage. At this time, the boost switch module is turned on, and the supply voltage is output to the boost circuit through the boost switch module. The boost circuit can increase the size of the supply voltage and reduce the situation where the supply voltage is reduced by temperature. When the supply voltage is greater than the upper limit voltage, it also indicates that the ambient temperature affects the voltage of the power supply line, resulting in an excessively high supply voltage. At this time, the buck switch module is turned on, and the supply voltage is output to the buck circuit through the buck switch module. The size of the supply voltage can be reduced by the buck circuit. It can be seen from this that by starting and turning on one of the buck switch module, the boost switch module and the comparison output module, the influence of the external ambient temperature on the resistance of the metal wiring can be reduced, ensuring the accuracy of the switch voltage within the surface, and reducing the abnormal display of the screen and the situation where the display screen cannot be turned on normally.

[0037] It should be understood that the above general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The drawings herein are incorporated into the specification and constitute a part of the specification, illustrate embodiments consistent with the present application, and together with the specification are used to explain the principles of the present application. Obviously, the drawings described below are only some embodiments of the present application, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0039] Figure 1 The circuit diagram of an embodiment of a gating circuit of the present application is schematically shown.

[0040] Figure 2The circuit diagram of the buck switch module in the gating circuit of the present application is schematically shown.

[0041] Figure 3 The schematic diagram of the circuit signal trend when the boost switch module in the gating circuit of the present application is turned on is shown schematically.

[0042] Figure 4 The schematic diagram of the circuit signal trend in which the comparison output module in the gating circuit of the present application plays a role is shown schematically.

[0043] Figure 5 The schematic diagram shows the circuit signal trend of the buck switch module in the gating circuit of the present application when it is turned on.

[0044] Figure 6 The schematic diagram schematically shows an embodiment of a control chip connected to a gating circuit in a display panel of the present application.

[0045] The following are the descriptions of the reference numerals:

[0046] VIN, power supply line; 110, buck switch module; 120, comparison output module; 130, boost switch module; 140, control chip; D1, first voltage-stabilizing diode; D2, second voltage-stabilizing diode; D3, third voltage-stabilizing diode; Q1, first transistor; Q2, second transistor; Q3, third transistor; T, response switch; R1, first current-limiting resistor; R2, second current-limiting resistor; R3, third current-limiting resistor; R4, fourth current-limiting resistor; R1, first voltage-dividing resistor; R2, second voltage-dividing resistor; Vout1, buck circuit; Vout2, boost circuit; Vout3, output circuit; V1, lower limit voltage; V2, upper limit voltage; V3, turn-on voltage; U1, first operational amplifier; U2, second operational amplifier; 131, first selection submodule; 132, second selection submodule. DETAILED DESCRIPTION

[0047] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in a variety of forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that this application will be more comprehensive and complete and fully convey the concept of the example embodiments to those skilled in the art.

[0048] Embodiment 1

[0049] See also Figure 1 As shown, a gating circuit includes: a power supply line VIN, a buck switch module 110 , a boost switch module 130 and a comparison output module 120 .

[0050] The power supply line VIN is connected to the power supply end, and the power supply end provides a power supply voltage to the power supply line VIN; the power supply line VIN is generally a metal line or a line whose resistivity is more likely to change when the temperature changes.

[0051] One end of the buck switch module 110 is connected to the power supply line VIN, and the other end of the buck switch module 110 is used to connect the buck circuit Vout1; the buck voltage is used to reduce the size of the power supply voltage. When the buck switch module 110 is started and turned on, the power supply voltage will flow to the buck circuit Vout1 through the buck switch module 110.

[0052] One end of the boost switch module 130 is connected to the power supply line VIN, and the other end of the boost switch module 130 is used to connect the boost circuit Vout2; when the boost switch module 130 is started and turned on, the supply voltage will flow to the boost circuit Vout2 through the boost switch module 130, and the boost circuit Vout2 will increase the size of the supply voltage.

[0053] One end of the comparison output module 120 is connected to the power supply line VIN, and the other end of the comparison output module 120 is used to connect the output circuit Vout3; when the comparison output module 120 is started and turned on, the power supply voltage is output normally and transmitted to the in-plane components of the display panel through the output circuit Vout3.

[0054] The specific process may be that the comparison output module 120 is used to receive the lower limit voltage V1 and the upper limit voltage V2, and the upper limit voltage V2 is greater than the lower limit voltage V1. Generally, if the supply voltage exceeds the upper limit voltage V2, it means that the supply voltage is too high and needs to be reduced. If the supply voltage is lower than the lower limit voltage V1, it means that the supply voltage is too low and needs to be boosted. If the supply voltage is between the lower limit voltage V1 and the upper limit voltage V2, it means that the supply voltage is normal, and the temperature has limited influence on the power supply line VIN. At this time, the supply voltage can be directly output.

[0055] For example, when the power supply voltage is between the lower limit voltage V1 and the upper limit voltage V2, the comparison output module 120 is turned on, and the buck switch module 110 and the boost switch module 130 are both disconnected. It can be understood that when the power supply voltage is within a normal fluctuation range, only the comparison output module 120 is turned on, while the buck switch module 110 and the boost switch module 130 are disconnected, thereby reducing the impact on the normal output power supply voltage of the power supply line VIN.

[0056] When the supply voltage is less than the lower limit voltage V1, the boost switch module 130 is turned on, and the buck switch module 110 and the comparison output module 120 are both disconnected; it can also be understood that when the supply voltage is less than the lower limit voltage V1, it means that the supply voltage is too low. At this time, only the boost switch module 130 is turned on, and the buck switch module 110 and the comparison output module 120 are both disconnected, reducing the impact on the boost process.

[0057] When the supply voltage is greater than the upper limit voltage V2, the buck switch module 110 is turned on, and the boost switch module 130 and the comparison output module 120 are both turned off. When the supply voltage is greater than the upper limit voltage V2, it means that the supply voltage is too high. At this time, the buck switch module 110 is turned on to reduce the voltage. The boost switch module 130 and the comparison output module 120 are both turned off to reduce the impact on the voltage reduction process.

[0058] In this embodiment, an upper limit voltage V2 and a lower limit voltage V1 are provided. When the supply voltage provided by the power supply line VIN is between the upper limit voltage V2 and the lower limit voltage V1, it indicates that the supply voltage is less affected by the ambient temperature. At this time, the comparison output module 120 starts to conduct, and the supply voltage is directly output through the output circuit Vout3 of the comparison output module 120. When the supply voltage is less than the lower limit voltage V1, it indicates that the ambient temperature affects the voltage of the power supply line VIN, resulting in a decrease in the supply voltage. At this time, the boost switch module 130 starts to conduct, and the supply voltage is output to the boost circuit Vout2 through the boost switch module 130. The boost circuit Vout2 can increase the supply voltage and reduce the situation where the supply voltage is reduced by the temperature. When the supply voltage is greater than the upper limit voltage V2, it also indicates that the ambient temperature affects the voltage of the power supply line VIN, resulting in an excessively high supply voltage. At this time, the buck switch module 110 starts to conduct, and the supply voltage is output to the buck circuit Vout1 through the buck switch module 110. The buck circuit Vout1 can reduce the supply voltage. It can be seen that by starting and turning on one of the buck switch module 110, the boost switch module 130 and the comparison output module 120, the influence of the external ambient temperature on the resistance of the metal wiring can be reduced, the accuracy of the switching voltage within the surface can be ensured, and the abnormal screen display and the failure of the display screen to turn on normally can be reduced.

[0059] In one embodiment of the present application, for the buck switch module 110, the buck switch module 110 includes a first voltage-stabilizing diode D1 and a first transistor Q1, the emitter of the first transistor Q1 is connected to the power supply line VIN, the collector of the first transistor Q1 is connected to the buck circuit Vout1, the anode of the first voltage-stabilizing diode D1 is connected to the base of the first transistor Q1, the cathode of the first voltage-stabilizing diode D1 is connected to the first grounding line, one end of the first grounding line is connected to the power supply line VIN, and the other end of the first grounding line is grounded.

[0060] When the supply voltage is less than the lower limit voltage V1, the first voltage regulator diode D1 is not conducting, the base of the first transistor Q1 does not receive a voltage signal, and the first transistor Q1 is turned off. The buck switch module 110 is in the off state, and the buck circuit Vout1 cannot intervene in the work.

[0061] It should be noted that in this embodiment, the first transistor Q1 can be a PNP transistor, and the voltage difference between the base and the emitter of the first transistor Q1 must be greater than the initial conduction voltage V3 of the emitter junction, so that the first transistor Q1 can be turned on.

[0062] When the supply voltage is greater than the lower limit voltage V1 but less than the upper limit voltage V2, the first voltage zener diode D1 is turned on, but the voltage difference between the base and the emitter of the first transistor Q1 is less than the turn-on condition of the first transistor Q1, the first transistor Q1 is still in the off state, and the step-down circuit Vout1 cannot intervene in the work.

[0063] When the supply voltage is greater than the upper limit voltage V2, the first voltage stabilizing diode D1 is turned on, and at the same time, the voltage difference between the base and the emitter of the first transistor Q1 satisfies the turn-on condition of the first transistor Q1, and the first transistor Q1 is turned on. The power supply line VIN is connected to the buck circuit Vout1 through the buck switch module 110, and the supply voltage is stepped down by the buck circuit Vout1, and the stepped-down supply voltage is then provided to the in-plane components of the display panel.

[0064] In one embodiment of the present application, the step-down switch module 110 also includes a first current limiting resistor R1 and a first voltage dividing resistor r1, and the first current limiting resistor R1 and the first voltage dividing resistor r1 are arranged on a first ground line; the cathode of the first voltage zener diode D1 is connected to a first node of the first ground line, one end of the first current limiting resistor R1 is connected to the first node, and the other end of the first current limiting resistor R1 is grounded; one end of the first voltage dividing resistor r1 is connected to the first node, and the other end of the first voltage dividing resistor r1 is connected to the power supply line VIN.

[0065] The first current limiting resistor R1 can reduce the current on the first grounding line and protect the first voltage zener diode D1. The first voltage divider voltage can share the voltage applied to the cathode of the first voltage zener diode D1, ensuring that the voltage applied to the first voltage zener diode D1 meets the design requirements.

[0066] In one embodiment of the present application, the lower limit voltage V1 is the threshold voltage of the first Zener diode D1. When the power supply voltage is lower than the lower limit voltage V1, that is, when the power supply voltage is lower than the threshold voltage of the first Zener diode D1, the first Zener diode D1 is in a disconnected state, and when the power supply voltage is greater than the threshold voltage of the first Zener diode D1, the first Zener diode D1 is turned on. It should be noted that when the first Zener diode D1 is turned on and stabilized, it is reverse breakdown conduction, that is, the cathode voltage of the first Zener diode D1 is greater than the threshold voltage, and the positive voltage signal is stabilized and thus loaded to the base of the first transistor Q1.

[0067] See also Figure 2As shown, in one embodiment of the present application, the boost switch module 130 includes a first gating submodule 131 and a second gating submodule 132; the threshold voltage of the first gating submodule 131 is an upper limit voltage V2, and the second gating submodule 132 has a turn-on voltage V3, and the turn-on voltage V3 is less than the lower limit voltage V1; one end of the first gating submodule 131 is connected to the power supply line VIN, and the other end of the first gating submodule 131 is grounded; one end of the second gating submodule 132 is connected to the power supply line VIN, and the other end of the second gating submodule 132 is connected to the boost circuit Vout2, and the second gating submodule 132 is connected to the first gating submodule 131.

[0068] When the power supply voltage is greater than the conduction voltage V3 and less than the lower limit voltage V1, it indicates that the power supply voltage is too low, the second selection submodule 132 is turned on, and the buck switch module 110 and the comparison output module 120 are both turned off. When the second selection submodule 132 is turned on, the power supply line VIN can be connected to the boost circuit Vout2, and the power supply voltage is increased by the boost circuit Vout2.

[0069] The supply voltage is less than the lower limit voltage V1, and is also less than the upper limit voltage V2, that is, the supply voltage is less than the threshold voltage of the first gating submodule 131, and the first gating submodule 131 is disconnected and does not intervene in the work.

[0070] In an embodiment of the present application, the first gating submodule 131 includes: a second voltage stabilizing diode D2 and a second transistor Q2 , and the second gating submodule 132 includes a third voltage stabilizing diode D3 and a response switch T.

[0071] The emitter of the second triode Q2 is connected to the power supply line VIN, the collector of the second triode Q2 is grounded, the anode of the second zener diode D2 is connected to the collector of the second triode Q2, the cathode of the second zener diode D2 is connected to the power supply line VIN, and the base of the second triode Q2 is connected to the line between the cathode of the second zener diode D2 and the power supply line VIN; the input end of the response switch T is connected to the power supply line VIN, the output end of the response switch T is connected to the boost circuit Vout2, the anode of the third zener diode D3 is connected to the collector of the second triode Q2, the cathode of the third zener diode D3 is connected to the power supply line VIN, and the control end of the response switch T is connected to the anode of the third zener diode D3. The turn-on voltage V3 of the second selection submodule 132 is the threshold voltage of the third zener diode D3.

[0072] The specific working process of the boost switch module 130 is as follows:

[0073] When the supply voltage is less than the lower limit voltage V1 and greater than the conduction voltage V3, the second voltage zener diode D2 is disconnected and does not conduct. In this way, the potential difference between the emitter and the base of the second transistor Q2 does not meet the conduction condition of the second transistor Q2, and the second transistor Q2 is cut off. The third voltage zener diode D3 is turned on, and the supply voltage on the power line VIN forms a clamping voltage through the third voltage zener diode D3. The clamping voltage is defined as V, and the supply voltage on the power line VIN is V0. After the voltage division of the third voltage zener diode D3, the gate of the response switch T, that is, the control end voltage is V0-V. At this time, the control end voltage of the response switch T is less than the voltage on the power line VIN, and meets the turn-on condition of the response switch T. The response switch T is turned on, and the power line VIN is connected to the boost circuit Vout2. The response switch T can be a P-type MOS tube.

[0074] When the supply voltage is between the lower limit voltage V1 and the upper limit voltage V2, the second voltage stabilizing diode D2 is still disconnected and not conducting. The potential difference between the emitter and the base of the second transistor Q2 satisfies the conduction condition of the second transistor Q2, and the second transistor Q2 is turned on. In response to the equal potentials of the control end and the input end of the switch T, the switch T is also disconnected, cutting off the connection between the boost switch module 130 and the boost circuit Vout2.

[0075] When the supply voltage is greater than the upper limit voltage V2, the second voltage stabilizing diode D2 is turned on, and the potential difference between the emitter and the base of the second transistor Q2 satisfies the conduction condition of the second transistor Q2, and the second transistor Q2 is turned on. As a result, the potentials of the control end and the input end of the response switch T are equal, and the response switch T is still turned off, cutting off the connection between the boost switch module 130 and the boost circuit Vout2.

[0076] In one embodiment of the present application, the first gating submodule 131 includes a second current limiting resistor R2, a third current limiting resistor R3 and a second voltage dividing resistor r2, and the second gating submodule 132 includes a fourth current limiting resistor R4; one end of the second current limiting resistor R2 is connected to the cathode of the second voltage zener diode D2, and the other end of the second current limiting resistor R2 is connected to the power supply line VIN; one end of the second voltage dividing resistor r2 is connected to the base of the second transistor Q2, and the other end of the second voltage dividing resistor r2 is connected to the line between the second current limiting resistor R2 and the second voltage zener diode D2; one end of the third current limiting resistor R3 is connected to the collector of the second transistor Q2, and the other end of the third current limiting resistor R3 is grounded; one end of the fourth current limiting resistor R4 is connected to the anode of the third voltage zener diode D3 and the control end of the response switch T, and the other end of the fourth current limiting resistor R4 is grounded.

[0077] The second current limiting resistor R2, the third current limiting resistor R3 and the fourth current limiting resistor R4 are used to reduce the current on the line to avoid excessive current and breakdown of the voltage-stabilizing diode or transistor. The second current limiting resistor R2 is used to protect the second voltage-stabilizing diode D2, and the third current limiting resistor R3 is used to protect the second transistor Q2. The fourth current limiting resistor R4 is used to protect the third voltage-stabilizing diode D3. The second voltage-dividing resistor r2 is used to protect the second transistor Q2, and is also used to share the voltage on the base of the second transistor Q2 to ensure that the voltage on the base of the second transistor Q2 meets the design requirements.

[0078] In one embodiment of the present application, the upper limit voltage V2 is the threshold voltage of the second voltage zener diode D2. The second voltage zener diode D2 is turned on only when the supply voltage is greater than the upper limit voltage V2, that is, greater than the threshold voltage of the second voltage zener diode D2. When the supply voltage is less than the upper limit voltage V2, that is, less than the threshold voltage of the second voltage zener diode D2, the second voltage zener diode D2 is turned off.

[0079] In one embodiment of the present application, the comparison output module 120 includes a first operational amplifier U1 and a second operational amplifier U2, the first operational amplifier U1 has a first same-direction input terminal and a first reverse input terminal, and the second operational amplifier U2 has a second same-direction input terminal and a second reverse input terminal; the first same-direction input terminal of the first operational amplifier U1 is used to receive the lower limit voltage V1, and the second reverse input terminal of the second operational amplifier U2 is used to receive the upper limit voltage V2, and the first reverse input terminal of the first operational amplifier U1 and the second same-direction input terminal of the second operational amplifier U2 are both connected to the power supply line VIN; the lower limit voltage V1 can be transmitted to the first operational amplifier U1 through the data line, and the upper limit voltage V2 can also be transmitted to the second operational amplifier U2 through other data lines. The first operational amplifier U1 can receive the lower limit voltage V1 and the power supply voltage, and compare the data sizes of the two. The second operational amplifier U2 can receive the upper limit voltage V2 and the power supply voltage, so as to compare the data sizes of the two.

[0080] The comparison output module 120 also includes a third transistor Q3, the output end of the first operational amplifier U1 and the output end of the second operational amplifier U2 are both connected to the base of the third transistor Q3, the collector of the third transistor Q3 is connected to the power supply line VIN, the emitter of the third transistor Q3 is grounded, and the output circuit Vout3 is connected to the collector of the third transistor Q3.

[0081] Regarding the working process of the comparison output module 120:

[0082] When the power supply voltage is less than the lower limit voltage V1, the power supply voltage of the power supply line VIN enters the first reverse input terminal of the first operational amplifier U1, and the power supply voltage also enters the second forward input terminal of the second operational amplifier U2. The output terminal of the second operational amplifier U2 has no output, the output terminal of the first operational amplifier U1 outputs a high level, the third transistor Q3 is turned on, the third transistor Q3 is connected to the ground, the voltage of the output circuit Vout3 is pulled down to the ground voltage, and the output circuit Vout3 has no output.

[0083] When the supply voltage is greater than the upper limit voltage V2, the output end of the first operational amplifier U1 has no output, the output end of the second operational amplifier U2 outputs a high level, the third transistor Q3 is turned on and grounded, the voltage of the output circuit Vout3 is pulled down to the ground voltage, and the output circuit Vout3 has no output.

[0084] When the supply voltage is between the lower limit voltage V1 and the upper limit voltage V2, the supply voltage of the first reverse input terminal of the first operational amplifier U1 is greater than the lower limit voltage V1 of the first non-inverting input terminal, and the first operational amplifier U1 has no output. The upper limit voltage V2 of the second reverse input of the second operational amplifier U2 is greater than the supply voltage of the second non-inverting input terminal, and the second operational amplifier U2 also has no output. It can be seen that the base terminal voltage acting on the third transistor Q3 is zero, and the third transistor Q3 is disconnected. The supply voltage is directly transmitted to the output circuit Vout3.

[0085] In order to further explain the working process of each stage in the present application, it is explained again according to the size of the power supply voltage. Among them, the first voltage zener diode D1, the second voltage zener diode D2 and the third voltage zener diode D3 all have the characteristic of reverse conduction. The first transistor Q1 and the second transistor Q2 can be PNP type, and the third transistor Q3 can be NPN type.

[0086] When the supply voltage of the power supply line VIN is less than the conduction voltage V3, that is, less than the threshold voltage of the third voltage stabilizing diode D3, it indicates that the supply voltage is too small and does not meet the requirements, and the buck switch module 110, the boost switch module 130 and the comparison output module 120 are all in the off state.

[0087] See also Figure 3 As shown, when the supply voltage is greater than or equal to the conduction voltage V3 and less than the lower limit voltage V1, the third voltage zener diode D3 conducts in reverse, and the control end of the response switch T receives the control voltage passing through the third voltage zener diode D3, and the response switch T is turned on, and the power supply line VIN connects to the boost circuit Vout2. At the same time, the first voltage zener diode D1 and the second voltage zener diode D2 are both in the off state, and the first voltage zener diode Q1 and the second voltage zener diode Q2 are turned off. The third transistor Q3 is in the on state, and the output circuit Vout3 is grounded. It can be seen that only the boost circuit Vout2 works.

[0088] See also Figure 4 As shown, when the supply voltage is greater than or equal to the lower limit voltage V1, and the supply voltage is less than or equal to the upper limit voltage V2, the first operational amplifier U1 and the second operational amplifier U2 have no output, the third transistor Q3 is disconnected, the comparison output module 120 plays a role, and the supply voltage is directly transmitted through the output circuit Vout3. At the same time, the first voltage stabilizing diode D1 is reversely conducted, but the first transistor Q1 does not meet the conduction condition, the first transistor Q1 is disconnected, the buck switch module 110 is in the off state, and the connection with the buck circuit Vout1 is disconnected. The supply voltage is lower than the threshold voltage of the second voltage stabilizing diode D2, and the second voltage stabilizing diode D2 is disconnected. The voltage at the base end of the second transistor Q2 will be lower than the voltage at the emitter, and the voltage difference makes the second transistor Q2 meet the conduction condition, but after the second transistor Q2 is turned on, the voltage at the control end and the input end of the response switch T are equal in potential, the control end of the response switch T does not meet the turn-on condition, and the response switch T is disconnected, so that the boost switch module 130 is also in the off state.

[0089] See also Figure 5 As shown, when the supply voltage is greater than the upper limit voltage V2, the first voltage stabilizing diode D1 is turned on, and at the same time, the voltage difference between the base and the emitter of the first transistor Q1 meets the conduction condition of the first transistor Q1, the emitter voltage of the first transistor Q1 is greater than the base voltage, the voltage difference meets the conduction condition, the first transistor Q1 is turned on, and the power supply line VIN is connected to the step-down circuit Vout1 through the step-down switch module 110 to step down the supply voltage. In the boost switch module 130, the second voltage stabilizing diode D2 is turned on, the potential difference between the collector and the base of the second transistor Q2 meets the conduction condition of the second transistor Q2, and the second transistor Q2 is also turned on. As a result, the potentials of the control end and the input end of the response switch T are equal, and the response switch T is still in the disconnected state, that is, the boost switch module 130 is disconnected from the boost circuit Vout2. At the same time, compared with the third transistor Q3 in the output module 120 being turned on, the voltage of the output circuit Vout3 is pulled down to the ground voltage, and the output circuit Vout3 has no output, or it can be understood that the output circuit Vout3 provides zero voltage.

[0090] Since the threshold voltages of different Zener diodes vary, in order to ensure that the first Zener diode D1, the second Zener diode D2 and the third Zener diode D3 can be turned on, the voltage difference between the emitter and the base is generally required to be greater than the difference between the upper and lower voltage limits.

[0091] Embodiment 2

[0092] See also Figure 6As shown, the present application also provides a display panel, the display panel includes a control chip 140 and a gating circuit as described above, the control chip 140 is connected to the power supply end of the gating circuit, and the control chip 140 provides a power supply voltage to the power supply line VIN. The gating circuit generally supplies power to the thin film transistor switch of the display panel to ensure that the thin film transistor switch can be accurately turned on or off, reduce the accidental start-up of the thin film transistor switch, thereby reducing the abnormality of the display screen and reducing the screen flicker.

[0093] The above-mentioned display panel can also be applied to mobile vehicles, such as vehicles, ships or airplanes. Especially for vehicles and ships, the ambient temperature environment of the mounted display panel will change, and sometimes may face extreme temperature environments. Such changes in ambient temperature will affect the resistivity of the data line in the display panel, and through the gating circuit in this embodiment, it is possible to select a start-up from the buck switch module 110, the boost switch module 130 and the comparison output module 120 according to the temperature, and output the switching voltage according to the ambient temperature, thereby reducing the impact of temperature changes on the resistivity of the data line. In addition, the above-mentioned display panel can also be used in some scenarios where the ambient temperature changes drastically.

[0094] Other specific implementations and beneficial effects of the display panel refer to the above-mentioned scheme of the gating circuit, which will not be described in detail here.

[0095] Those skilled in the art will readily appreciate other embodiments of the present application after considering the specification and practicing the invention disclosed herein. The present application is intended to cover any modification, use or adaptation of the present application, which follows the general principles of the present application and includes common knowledge or customary technical means in the art that are not disclosed in the present application.

[0096] It should be understood that the present application is not limited to the precise structures that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present application is limited only by the appended claims.

Claims

1. A gating circuit, characterized in that: The gating circuit comprises: A power supply line, the power supply line is connected to a power supply terminal, and the power supply terminal provides a power supply voltage to the power supply line; A step-down switch module, one end of which is connected to the power supply line, and the other end of which is used to connect to a step-down circuit; A boost switch module, one end of which is connected to the power supply line, and the other end of which is used to connect to a boost circuit; A comparison output module, one end of which is connected to the power supply line, and the other end of which is used to connect to an output circuit; The comparison output module is used to receive a lower limit voltage and an upper limit voltage, the upper limit voltage is greater than the lower limit voltage, and when the supply voltage is between the lower limit voltage and the upper limit voltage, the comparison output module is turned on, and the buck switch module and the boost switch module are both turned off; The supply voltage is less than the lower limit voltage, the boost switch module is turned on, and the buck switch module and the comparison output module are both turned off; When the supply voltage is greater than the upper limit voltage, the step-down switch module is turned on, and the step-up switch module and the comparison output module are both turned off.

2. The gating circuit according to claim 1, characterized in that: The step-down switch module includes a first voltage-stabilizing diode and a first transistor, the emitter of the first transistor is connected to the power supply line, the collector of the first transistor is connected to the step-down circuit, the anode of the first voltage-stabilizing diode is connected to the base of the first transistor, the cathode of the first voltage-stabilizing diode is connected to the first grounding wire, one end of the first grounding wire is connected to the power supply line, and the other end of the first grounding wire is grounded.

3. The gating circuit according to claim 2, characterized in that: The step-down switch module further includes a first current limiting resistor and a first voltage dividing resistor, wherein the first current limiting resistor and the first voltage dividing resistor are arranged on the first ground line; The cathode of the first voltage-limiting diode is connected to the first node of the first grounding line, one end of the first current-limiting resistor is connected to the first node, and the other end of the first current-limiting resistor is grounded; One end of the first voltage-dividing resistor is connected to the first node, and the other end of the first voltage-dividing resistor is connected to the power supply line.

4. The gating circuit according to claim 2, characterized in that: The lower limit voltage is a threshold voltage of the first voltage zener diode.

5. The gating circuit according to claim 1, characterized in that: The boost switch module includes a first gating submodule and a second gating submodule; The threshold voltage of the first gating submodule is the upper limit voltage, and the second gating submodule has a conduction voltage, which is less than the lower limit voltage; One end of the first gating submodule is connected to the power supply line, and the other end of the first gating submodule is grounded; One end of the second gating submodule is connected to the power supply line, the other end of the second gating submodule is connected to the boost circuit, and the second gating submodule is connected to the first gating submodule; When the supply voltage is greater than the turn-on voltage and less than the lower limit voltage, the second gating submodule is turned on, and the step-down switch module and the comparison output module are both turned off.

6. The gating circuit according to claim 5, characterized in that: The first gating submodule includes: a second voltage stabilizing diode and a second triode, and the second gating submodule includes a third voltage stabilizing diode and a response switch; The emitter of the second transistor is connected to the power supply line, the collector of the second transistor is grounded, the anode of the second voltage zener diode is connected to the collector of the second transistor, the cathode of the second voltage zener diode is connected to the power supply line, and the base of the second transistor is connected to the line between the cathode of the second voltage zener diode and the power supply line; The input end of the response switch is connected to the power supply line, the output end of the response switch is connected to the boost circuit, the anode of the third voltage regulator diode is connected to the collector of the second transistor, the cathode of the third voltage regulator diode is connected to the power supply line, and the control end of the response switch is connected to the anode of the third voltage regulator diode.

7. The gating circuit according to claim 6, characterized in that: The first gating submodule includes a second current limiting resistor, a third current limiting resistor and a second voltage dividing resistor, and the second gating submodule includes a fourth current limiting resistor; One end of the second current limiting resistor is connected to the cathode of the second voltage stabilizing diode, and the other end of the second current limiting resistor is connected to the power supply line; One end of the second voltage-dividing resistor is connected to the base of the second transistor, and the other end of the second voltage-dividing resistor is connected to the line between the second current-limiting resistor and the second voltage-stabilizing diode; One end of the third current limiting resistor is connected to the collector of the second transistor, and the other end of the third current limiting resistor is grounded; One end of the fourth current limiting resistor is connected to the anode of the third voltage stabilizing diode and the control end of the response switch, and the other end of the fourth current limiting resistor is grounded.

8. The gating circuit according to claim 6, characterized in that: The upper limit voltage is a threshold voltage of the second voltage zener diode.

9. The gating circuit according to any one of claims 1 to 8, characterized in that: The comparison output module comprises a first operational amplifier and a second operational amplifier, the first operational amplifier having a first non-inverting input terminal and a first reverse input terminal, and the second operational amplifier having a second non-inverting input terminal and a second reverse input terminal; The first non-inverting input terminal of the first operational amplifier is used to receive the lower limit voltage, the second inverting input terminal of the second operational amplifier is used to receive the upper limit voltage, and the first inverting input terminal of the first operational amplifier and the second non-inverting input terminal of the second operational amplifier are both connected to the power supply line; The comparison output module also includes a third transistor, the output end of the first operational amplifier and the output end of the second operational amplifier are both connected to the base of the third transistor, the collector of the third transistor is connected to the power supply line, the emitter of the third transistor is grounded, and the output circuit is connected to the collector of the third transistor.

10. A display panel, characterized in that: The display panel comprises a control chip and a gating circuit as claimed in any one of claims 1 to 9, wherein the control chip is connected to a power supply terminal of the gating circuit, and the control chip provides the power supply voltage to the power supply line.

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