Summary of the invention
In order to solve the above technical problems, the invention discloses a kind of control circuit of display device, display device and its controls
Method processed, effectively prevent display device shut down when power supply signal after decline again rise to booting detecting voltage caused by
Timing of shutting down is abnormal.
Technical solution provided by the invention is as follows:
The invention discloses a kind of control circuit of display device, the control circuit of the display device includes: maintenance control
Module, the maintenance control module include node control submodule and switch submodule;Node control submodule and switch submodule
Block is connected to maintenance control node;The node control submodule include the second field-effect tube, first resistor, second resistance and
The grid input of 3rd resistor, the second field-effect tube maintains control signal and is grounded through 3rd resistor, the source of the second field-effect tube
Pole connection maintains control node, the grounded drain of the second field-effect tube;Analog signal inputs through first resistor and maintains control node;
Control node is maintained to be grounded through second resistance;The switch submodule includes the first field-effect tube, the grid of the first field-effect tube
The maintenance control node is connected, the source electrode of the first field-effect tube inputs power supply signal, and the drain electrode of the first field-effect tube exports electricity
Source signal;When display device shutdown, control signal is maintained to rise to high level, the shutdown of the second field-effect tube by low level;Power supply
The voltage of signal is reduced to shutdown detecting voltage by default supply voltage, and the voltage of control node is maintained to rise to the by ground potential
One control voltage, the shutdown detecting voltage and the first control voltage meet the turn-off criterion of the first field-effect tube.
Preferably, first field-effect tube and the second field-effect tube are p-type field-effect tube.
Preferably, the control circuit of the display device further includes discharge module, and the discharge module includes third field-effect
Pipe;The grid input of third field-effect tube maintains control signal, the source electrode ground connection of third field-effect tube, the leakage of third field-effect tube
Pole input power supply signal simultaneously connects maintenance control module.
Preferably, the third field-effect tube is N-shaped field-effect tube.
Preferably, the first resistor, second resistance and the second field-effect tube meet:
UVLO1*r2/(r1+r2) >-Vth2,
Wherein r1For the resistance value of first resistor, r2For the resistance value of second resistance, UVLO1 is booting detecting voltage, Vth2
For the threshold voltage of the second field-effect tube.
Preferably, the first resistor, second resistance and the first field-effect tube meet:
UVLO1*r1/(r1+r2) >-Vth1,
Wherein r1For the resistance value of first resistor, r2For the resistance value of second resistance, UVLO1 is booting detecting voltage, Vth1
For the threshold voltage of the first field-effect tube.
Preferably, the first resistor, second resistance and the first field-effect tube meet:
VIN1-AVDD1*r2/(r1+r2) <-Vth1,
Wherein r1For the resistance value of first resistor, r2For the resistance value of second resistance, Vth1 is the threshold value of the first field-effect tube
Voltage, AVDD1For the voltage value of the analog signal described when power supply signal is reduced to shutdown detecting voltage, VIN1Voltage value etc.
Voltage is detected in shutdown.
The invention also discloses a kind of display device, which includes the control of display device described in any of the above embodiments
Circuit processed.
The invention also discloses a kind of control method of display device, the control method of the display device can be applied to one kind
Display device, the display device include the control circuit of display device described in any of the above embodiments, the control of the display device
Method the following steps are included:
When display device works normally, the input of node control submodule is located at low level maintenance control signal and is located at
The analog signal of predetermined analog voltage, the conducting of the second field-effect tube make the maintenance control node for connecting the second field-effect tube source electrode
Ground connection;The source electrode input for switching the first field-effect tube in submodule is located at the power supply signal of high level, the grid of the first field-effect tube
Pole connection is located at the maintenance control node of ground potential, and the first field-effect tube is opened;
When display device shutdown, the maintenance control signal of input node control submodule rises to high level by low level,
Second field-effect tube shutdown, so that being connected to that the voltage of the first fet gate of control node is maintained to be risen to by ground potential
Higher than the first control voltage, while the voltage for inputting the power supply signal of the first field-effect tube source electrode is reduced to by default supply voltage
The voltage difference of shutdown detecting voltage, shutdown detecting voltage and the grid voltage of the first field-effect tube after variation meets first effect
Should pipe turn-off criterion so that the first field-effect tube turn off.
Compared with prior art, the present invention can bring it is at least one of following the utility model has the advantages that
1, when display device is shut down and when power supply signal powered-off fault, control circuit makes die terminals power supply and power supply
It disconnects, i.e., the power supply signal voltage influence that the voltage of the power supply signal exported in control circuit is not inputted prevents power supply signal
There is shutdown spring, guarantees that shutdown timing is normal;
2, when display device is shut down, discharge module accelerates power supply electric discharge, and power supply signal is avoided to rise to out again
Machine detects voltage.
Specific embodiment
In order to more clearly explain the embodiment of the invention or the technical proposal in the existing technology, Detailed description of the invention will be compareed below
A specific embodiment of the invention.It should be evident that drawings in the following description are only some embodiments of the invention, for
For those of ordinary skill in the art, without creative efforts, it can also be obtained according to these attached drawings other
Attached drawing, and obtain other embodiments.
To make simplified form, part related to the present invention is only schematically shown in each figure, they are not represented
Its practical structures as product.In addition, there is identical structure or function in some figures so that simplified form is easy to understand
Component only symbolically depicts one of those, or has only marked one of those.
Display device of the invention includes power supply, die terminals power supply and control circuit, control circuit connection power supply electricity
Source and die terminals power supply.Power supply exports power supply signal VIN to control circuit, and power supply signal VIN is reduced from high level rapidly
It is known as power down to low level process, Chang Fasheng is when display device is shut down.Control circuit inputs power supply signal VIN, and exports
Power supply signal VDD is to die terminals power supply, and when power supply signal VDD power down, control circuit is by power supply and die terminals power end
It opens, i.e., the power supply signal VDD exported in control circuit is not influenced by the power supply signal VIN size inputted.Die terminals power input
Power supply signal VDD, and control the work of the multiple circuit modules of die terminals.
Fig. 3 is the circuit diagram of the control circuit of the display device of that present invention, and control circuit includes maintaining control module 01
With discharge module 02.Maintain 01 input control signal VSS of control module, analog signal AVDD and power supply signal VIN, output electricity
Source signal VDD.Control module 01 is maintained to be responsible for when power supply signal VIN maintains high level, output voltage values are in default power supply
The power supply signal VDD of voltage, and be responsible in power supply signal VIN power down disconnect power supply signal VIN and power supply signal VDD, i.e., this
When control circuit output power supply signal VDD do not influenced by the power supply signal VIN inputted.Discharge module 02 inputs power supply signal
VIN and control signal VSS, discharge module 02 is responsible for will power supply electricity when power supply signal VIN is down to low level by high level rapidly
Source electric discharge, makes power supply signal VIN be reduced to ground potential GND.
As shown in figure 3, maintaining control module 01 includes node control submodule 01A and switch submodule 01B, node control
Submodule 01A and switch submodule 01B are connected to and maintain control node netA.Node control submodule 01A includes second
Effect pipe MOS2, first resistor R1, second resistance R2 and 3rd resistor R3;Switching submodule 01B includes the first field-effect tube
MOS1.First field-effect tube MOS1 and the second field-effect tube MOS2 is p-type field-effect tube.
The source electrode of the grid of first field-effect tube MOS1 and the second field-effect tube MOS2 are connected to maintenance control node
netA.Analog signal AVDD is inputted through first resistor R1 and is maintained control node netA;Maintain control node netA again through the second electricity
Hinder R2 ground connection.
The grid input of second MOS field effect transistor MOS2 maintains control signal VSS and is grounded through 3rd resistor R3, the second MOS field effect transistor
The source electrode connection of MOS2 maintains control node netA, the grounded drain of the second MOS field effect transistor MOS2.
The grid connection of first field-effect tube MOS1 maintains control node netA, the source electrode input of the first field-effect tube MOS1
Power supply signal VIN, and connect discharge module 02;The drain electrode out-put supply signal VDD of first field-effect tube MOS1.
Discharge module 02 includes third field-effect tube MOS3, and third field-effect tube MOS3 is N-shaped field-effect tube.Third field effect
Should pipe MOS3 grid input maintain control signal VSS;The source electrode of third field-effect tube MOS3 is grounded;Third field-effect tube MOS3
Drain electrode input power supply signal VIN, and connect maintain control module 01.
The working timing figure of the main signal of driving circuit is as shown in figure 4, illustrate present invention driving electricity below in conjunction with Fig. 4
The working principle on road:
The signal of input control circuit includes power supply signal VIN, maintains control signal VSS and analog signal AVDD,
In: the voltage of power supply signal VIN rises to default supply voltage by ground potential GND when display device is switched on, and when normal work ties up
Supply voltage is held, ground potential GND is down to by supply voltage in display device shutdown.Maintain control signal VSS in display device
When booting, (i.e. level translator Level shift IC start to work after) is down to low by ground potential GND after delay time Td
Level VGL maintains low level VGL when normal work, is rapidly increased to high level VGH by low level VGL in display device shutdown,
It is slowly drop down to ground potential GND later.Analog signal AVDD display device be switched on when without input, when power supply signal VDD is higher than
After booting detecting voltage UVLO1, multiple circuit modules of die terminals are started to work, and analog signal AVDD starts input and by being switched on
Detecting voltage UVLO1 gradually rises to predetermined analog voltage, and when normal work maintains analog voltage, in display device shutdown by
Analog voltage gradually decreases down ground potential GND.
As shown in figure 4, power supply signal VIN, maintaining control signal VSS, power supply signal VDD, mould before display device booting
Quasi- signal AVDD is in ground potential GND, the first field-effect tube MOS1, the second field-effect tube MOS2, third field-effect tube MOS3
It is in closed state.
When display device is switched on, as the power supply signal VIN of input starts to increase, the source electrode one of the first field-effect tube MOS1
Side voltage is raised, and grid side is still ground potential GND, note the first field-effect tube MOS1 gate-source voltage difference be Vgs1, first
The threshold voltage of field-effect tube MOS1 is Vth1, as satisfaction-Vgs1 >-Vth1, the first field-effect tube MOS1 conducting, and power supply letter
Number VDD starts to input die terminals power supply.As power supply signal VIN is persistently increased, power supply signal VDD is also increased, and works as power supply
When the voltage of signal VDD is higher than booting detecting voltage UVLO1, multiple circuit modules of die terminals are started to work, analog signal
AVDD starts input and the voltage value of analog signal AVDD gradually rises by booting detecting voltage UVLO1.
Due to maintaining control signal VSS just to begin to decline after level translator Level shift IC start-up operation, because
The grid side of this second field-effect tube MOS2 before delay time Td is still ground potential GND.Make second in design
The threshold voltage vt h2 of effect pipe MOS2 meets:
UVLO1*r2/(r1+r2) >-Vth2,
Wherein r1For the resistance value of first resistor R1, r2For the resistance value of second resistance R2, UVLO1 is booting detecting voltage,
Vth2 is the threshold voltage of the second field-effect tube MOS2.Then when power supply signal VDD once be higher than booting detecting voltage UVLO1 when,
The gate-source voltage difference Vgs2 of second field-effect tube MOS2 meets :-Vgs2 >-Vth2, the second field-effect tube MOS2 are opened, and are maintained
Control node netA is pulled low to ground potential GND.
Moment the second field-effect tube MOS2 simultaneously in order to avoid the generation of indefinite situation, such as in analog signal AVDD starting
It does not open successfully, the first field-effect tube MOS1 is turned off again, causes control circuit that can not be operating normally;Preferably, it is designing
When meet the threshold voltage vt h1 of the first field-effect tube MOS1:
UVLO1*r1/(r1+r2)>-Vth1
Wherein r1For the resistance value of first resistor R1, r2For the resistance value of second resistance R2, UVLO1 is booting detecting voltage,
Vth1 is the threshold voltage of the first field-effect tube MOS1.Then analog signal AVDD establish moment the first field-effect tube MOS1 not
It can be turned off.
After power supply signal VDD maintains a period of time, analog signal AVDD persistently rises, since the second field-effect tube MOS2 is beaten
It opens, the source voltage of the second field-effect tube MOS2 is still ground potential GND.After delay time Td, level translator Level shift
IC starts to act, and control signal VSS is maintained to be reduced to low level VGL, the grid electricity of the second field-effect tube MOS2 by ground potential GND
Pressure drop is low, and-Vgs2 >-Vth2 is still met, therefore the second field-effect tube MOS2 is persistently maintained open state.
When display device shutdown, power supply signal VIN declines rapidly, and power supply signal VDD drops to shutdown detecting voltage
UVLO2 or less;Level translator Level shift IC executes shutdown movement, maintains control signal VSS rapidly by low level VGL
High level VGH is risen to, because the voltage value of high level VGH is the several times of analog signal AVDD voltage value, the second field-effect tube
MOS2 meets :-Vgs2 <-Vth2, the second field-effect tube MOS2 shutdown maintain the voltage of control node netA by the first electricity at this time
The partial pressure for hindering R1 and second resistance R2 determines.
Postboost sometime node is selected, as the voltage value of power supply signal VIN drops to shutdown detecting voltage UVLO2
When, in design meet the first field-effect tube MOS1:
VIN1-AVDD1*r2/(r1+r2) <-Vth1,
Wherein r1For the resistance value of first resistor R1, r2For the resistance value of second resistance R2, Vth1 is the first field-effect tube
The threshold voltage of MOS1, AVDD1For the electricity of the analog signal AVDD when power supply signal VIN is reduced to shutdown detecting voltage UVLO2
Pressure value, the voltage value of VIN1 are equal to shutdown detecting voltage UVLO2.I.e. the voltage of analog signal AVDD is higher than the second control voltage,
Then maintain voltage (the i.e. voltage AVDD at the both ends second resistance R2 of control node netA1* r2/ (r1+r2)) it is higher than the first control
Voltage, the shutdown control voltage of detecting voltage UVLO2 and first meet the turn-off criterion of the first field-effect tube MOS1, the first field-effect
Pipe MOS1 shutdown, cut off power supply and die terminals power supply connection, i.e. the voltage of power supply signal VDD do not inputted for telecommunications
Number VIN influences.After the first field-effect tube MOS1 shutdown, power supply signal VDD is gradually used up to ground potential GND.
Simultaneously because maintain the voltage of control signal VSS at this time higher, the threshold voltage vt h3 of third field-effect tube MOS3
Meet Vgs3 > Vth3 with the gate-source voltage difference Vgs3 of third field-effect tube MOS3, third field-effect tube MOS3 is opened, and accelerates to supply
The electric discharge of power supply.Due to maintaining the voltage decline of control signal VSS and analog signal AVDD slower, can be tieed up in high potential
The long period is held, within the time of the first field-effect tube MOS1 shutdown, discharge module 02 discharges power supply, makes power supply signal
Ground potential GND is down to by default supply voltage, then avoids power supply signal VDD and rises to booting detecting voltage UVLO1's again
Situation ensure that normal shutdown timing.
It should be noted that the shutdown of the first field-effect tube MOS1 necessarily occurs under the voltage value of power supply signal VIN
Drop to shutdown detecting voltage UVLO2 when or before, it is only necessary to be chosen at the postboost sometime node of display device, guarantee
The first field-effect tube MOS1 is turned off before the timing node, i.e., should fall into protection scope of the present invention.
The invention discloses a kind of control circuit of display device, when display device shutdown, maintain control signal VSS by
Low level VGL rises to high level VGH, the second field-effect tube MOS2 shutdown;The voltage of power supply signal VIN is by under default supply voltage
It is down to shutdown detecting voltage UVLO2, maintains the voltage of control node netA to rise to the first control voltage by ground potential GND, closes
Machine detects the turn-off criterion that the control voltage of voltage UVLO2 and first meets the first field-effect tube, and power supply signal VDD is avoided to decline
Rise to again afterwards booting detecting voltage cause shutdown after be switched on again rapidly shutdown;The invention also discloses apply the control circuit
Display device and its control method.
It should be noted that above-described embodiment can be freely combined as needed.The above is only of the invention preferred
Embodiment, it is noted that for those skilled in the art, in the premise for not departing from the principle of the invention
Under, multiple improvements and modifications can also be made, these modifications and embellishments should also be considered as the scope of protection of the present invention.