CN104200790B - Voltage switching circuit, liquid crystal panel drive circuit and liquid crystal display - Google Patents
Voltage switching circuit, liquid crystal panel drive circuit and liquid crystal display Download PDFInfo
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- CN104200790B CN104200790B CN201410480146.0A CN201410480146A CN104200790B CN 104200790 B CN104200790 B CN 104200790B CN 201410480146 A CN201410480146 A CN 201410480146A CN 104200790 B CN104200790 B CN 104200790B
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Abstract
The invention discloses a voltage switching circuit, a liquid crystal panel drive circuit and a liquid crystal display. The voltage switching circuit comprises a charge pump circuit, a boosted circuit and a switching circuit. The charge pump circuit is a capacitive adjusting circuit. The charge pump circuit receives pulse signals output by a pulse signal generating device and performs voltage regulating and rectification on the pulse signals so as to output first grid turn-on voltage. The boosted circuit is used for outputting second grid turn-on voltage. The amplitude of the second grid turn-on voltage can be adjusted by changing the values of a peripheral voltage dividing resistor. The switching circuit is connected with the charge pump circuit and the boosted circuit and used for switching to output the first grid turn-on voltage or the second grid turn-on voltage. The liquid crystal panel drive circuit and the liquid crystal display adopt the voltage switching circuit. The voltage switching circuit is simple in circuit peripheral structure, few in device and low in cost.
Description
Technical field
The present invention relates to field of liquid crystal display, more particularly to a kind of voltage conversion circuit, liquid crystal panel drive circuit
And liquid crystal display.
Background technology
Liquid crystal display (TFT-LCD) pollution etc. that has that external form is frivolous, the few one-level of power consumption is radiationless in recent years
Feature, has been widely used in the portable information products such as notebook computer, personal digital assistant (PDA)
On, wherein, liquid crystal display mainly includes liquid crystal panel and drive module, and drive module provides liquid crystal panel institute
The drive signal of needs.
Fig. 4 is liquid crystal panel drive circuit module diagram in prior art.As shown in figure 4, liquid crystal display
The drive module of module mainly includes：DC voltage converting circuit (DC/DC Converter), gamma correction electricity
Road (Gamma correction), sequential control circuit (Timing controller), gate driver circuit
(Gate driver), source class drive circuit (Source driver).Wherein, charge pump circuit is unidirectional current
The circuit module of gate turn-on voltage (VGH) is produced in voltage conversion circuit.
Wherein, liquid crystal panel drive circuit is mainly input into LVDS signals to sequencing contro electricity by interface connector
Road module T-CON, generates mini LVDS signals by T-CON and enters Source driver.Source driver
Receive the control signal of T-CON and mini LVDS signals are converted into into voltage data and export to display floater.
T-CON causes Gate driver to beat by exporting the control signals such as STV, CPV line by line to Gate driver
Open the TFT switch in display floater.When Gate driver are exported to panel high voltage VGH, now TFT
Switch is opened the pixel electrode to display floater and is charged, when Gate driver are exported to panel low-voltage VGL
When, the data voltage that TFT switch is closed on pixel electrode keeps.Wherein DC voltage converting circuit module DC/DC
Necessary running voltage is provided to T-CON, Gamma module, Gate driver, Source driver.By
This understands that gate turn-on voltage (VGH) ensures pixel information voltage when being exactly and opening as control TFT switch
The condition that fully can be write.The scope of this gate turn-on voltage is typically in 10.xxV～31.xxV.
In prior art, the general grid produced using charge pump circuit module needed for display panels opens electricity
Pressure VGH, but the charge pump circuit module for producing VGH in prior art also has the disadvantage that：For large scale
Panel for the gate turn-on voltage that needs and grid current all than larger, thus may require that electric charge pump module
Larger output is provided, but with the increase of output, the transformation efficiency of charge pump circuit declines meeting
Than more serious.
For some PMIC do not design charge pump circuit output feedback voltage for cost perhaps other considerations
(FBP),
It is difficult to adjust the accurate gate turn-on voltage of output.General traditional way is to use charge pump in this case
The gate turn-on voltage that output slab needs after connecting LDO blood pressure lowerings after the higher voltage of circuit output.
But although this kind of mode can export the gate turn-on voltage of degree of precision, according to the characteristic of LDO,
Larger thermal losses is generated as cost with LDO often, the feelings larger for grid current needed for large size panel
Under condition, the heat energy of loss is more projected.
The content of the invention
In view of this, the present invention is directed to the deficiencies in the prior art, and the present invention proposes a kind of voltage conversion circuit, liquid
Crystal face drive circuit and liquid crystal display, by the electric current of change-over circuit real-time monitoring TFT gate, according to electricity
The size of stream supplies the accurate grid of liquid crystal panel grid to switch with boost module or charge pump circuit modular manner
Pole cut-in voltage, to reach efficient working method.
In order to solve above-mentioned technical problem, one embodiment of the invention proposes a kind of voltage conversion circuit, and which includes：
Charge pump circuit, the charge pump circuit are a condenser type adjustment circuit, its return pulse signal generating meanss output
Pulse signal, and carry out pressure regulation and rectification to the pulse signal and process, so as to export first grid cut-in voltage；
Booster circuit, for exporting second grid cut-in voltage, the big I of amplitude of the second grid cut-in voltage is led to
The value for crossing peripheral divider resistance changes and adjusts；Change-over circuit, which connects the charge pump circuit and the liter
Volt circuit, for switching output first grid cut-in voltage or second grid cut-in voltage.
Also include that the voltage conversion circuit exports first and second gate turn-on voltage to liquid crystal panel, work as electricity
Reference value of the stream less than the liquid crystal panel grid current, it is defeated that the change-over circuit switches to the charge pump circuit
Go out the first grid cut-in voltage, when electric current more than the liquid crystal panel grid current reference value, described turn
Change circuit and switch to the booster circuit output second grid cut-in voltage.
The change-over circuit includes：First switch unit, control export the first grid cut-in voltage to institute
State liquid crystal panel；Second switch unit, control export the second grid cut-in voltage to the liquid crystal panel；
The change-over circuit includes：First switch unit includes the first p-type metal-oxide-semiconductor, the second p-type metal-oxide-semiconductor, second
Switch element includes the 3rd p-type metal-oxide-semiconductor；The first and second p-type metal-oxide-semiconductor conducting, the 3rd p-type metal-oxide-semiconductor are closed
Close, the charge pump circuit in running order output first grid cut-in voltage and at the booster circuit
In off working state；The first and second p-type metal-oxide-semiconductor is closed, the 3rd p-type metal-oxide-semiconductor conducting, the electric charge
Pump circuit is in off working state and the booster circuit in running order output second grid opens electricity
Pressure.
Improve as one, the condenser type adjustment circuit includes storage capacitor unit and diode, which is driving
The first grid cut-in voltage is pumped out under the alternating action of dynamic switch.
As one improve, the storage capacitor unit be the first storage capacitor, the second storage capacitor, the one or two
The negative pole of pole pipe connects the positive pole of the second diode, the first storage capacitor be connected on the DRVP ports of charge pump circuit with
Between first diode cathode；Second storage capacitor is connect between the output of charge pump circuit and GND；5th
Termination the second diode cathode one of resistance one terminates the FBP ports of charge pump circuit；6th resistance one terminates electric charge
The termination GND of FBP ports one of pump circuit.
Improve as one, the change-over circuit is specifically included：The first p-type metal-oxide-semiconductor source electrode connects charge pump electricity
The SUPP ports on road, drain electrode connect the positive pole of the first diode, and grid connects the backward end of second voltage comparator；
Sampling resistor one terminates the negative pole of the second diode and one end of second resistance, one end of another termination first resistor；
The other end of the other end of second resistance and first resistor connects the reverse input end of difference amplifier and forward direction respectively
Input；Feedback resistance is connected between the positive input and outfan of the difference amplifier；3rd resistor connects
Between the reverse input end and GND of the difference amplifier；The just termination difference of first voltage comparator
The outfan of amplifier；The grid of the output second p-type metal-oxide-semiconductor of termination of first voltage comparator and second voltage
The backward end of comparator, the source electrode of the second p-type metal-oxide-semiconductor are connect between sampling resistor and first resistor, drain electrode output
To panel；The grid of the 3rd p-type metal-oxide-semiconductor connects the outfan of the second voltage comparator, and source electrode connects charge pump
The SUPP ports of circuit, drain electrode connect the VIN ports of booster circuit.
Improve as one, the booster circuit includes：Boost module, input capacitance are connected on the boost module
Between VIN ports and GND；Inductance is connected between the VIN ports of the boost module and LX ports；Three or two pole
The LX ports of boost module described in the positive pole of pipe, negative pole connect one end of pull-up resistor and export to panel；Drop-down electricity
Resistance is connected between the FB ports of the boost module and GND；Output capacitance be connected on the 3rd diode cathode with
Between GND.
In order to solve above-mentioned technical problem, another embodiment of the present invention proposes a kind of liquid crystal panel drive circuit,
Which includes one for driving the drive integrated circult of liquid crystal panel, and the drive integrated circult includes voltage conversion electricity
Road, it is characterised in that：The voltage conversion circuit is the voltage conversion circuit described in above-described embodiment.
In order to solve above-mentioned technical problem, further embodiment of this invention proposes a kind of liquid crystal display, and which includes
One liquid crystal panel and a liquid crystal panel drive circuit, the liquid crystal panel drive circuit are provided normally for the liquid crystal panel
Running voltage and working signal needed for work, which includes that one is driven with working signal for producing the running voltage
Integrated circuit, the drive integrated circult include a voltage conversion circuit, it is characterised in that：The voltage conversion circuit
For the voltage conversion circuit described in above-described embodiment.
The present invention compared with prior art, has an advantage in that：The key problem in technology point of voltage conversion circuit is to drive electricity
Road is suitable for the magnitude of voltage required for sizes panel is opened to TFT gate.Charge pump circuit module and boosting
Module mutually flexibly switches according to the detection to grid current.Circuit power consumption is reduced to greatest extent improves turning for system
Change efficiency.
Description of the drawings
Fig. 1 is voltage conversion circuit principle schematic of the present invention；
Fig. 2 is charge pump circuit principle schematic of the present invention；
Fig. 3 is booster circuit principle schematic of the present invention；
Fig. 4 is liquid crystal panel drive circuit module diagram in prior art.
Main Reference Numerals explanation：
Charge pump circuit -1, change-over circuit -2, booster circuit -3；
Charge pump-IC1, boost module-IC2；
First p-type metal-oxide-semiconductor-Q1, the second p-type metal-oxide-semiconductor-Q2, the 3rd p-type metal-oxide-semiconductor-Q3；
First diode-D1, the second diode-D2, the 3rd diode-D3；
L- inducer difference amplifier-U1；
First voltage comparator-U2A second voltage comparator-U2B；
First resistor-R1, second resistance-R2,3rd resistor-R3, feedback resistance-Rf, the 5th resistance-R5, the 6th
Resistance-R6, pull-up resistor-Ra, pull down resistor-Rb, sampling resistor-Rs；
First storage capacitor-CFLY, the second storage capacitor-Cout, input capacitance-Cin, output capacitance-Co.
Specific embodiment
The present invention is further illustrated with embodiment below in conjunction with the accompanying drawings.
Fig. 1 is voltage conversion circuit principle schematic of the present invention.As shown in figure 1, one embodiment of the invention is proposed
A kind of voltage conversion circuit, which includes：Charge pump circuit 1, the charge pump circuit 1 are a condenser type adjustment circuit,
The pulse signal of its output of return pulse signal generating meanss 4, and the pulse signal is carried out at pressure regulation and rectification
Reason, so that export first grid cut-in voltage VGH1；Booster circuit 3, for exporting second grid cut-in voltage
The big I of amplitude of VGH2, the second grid cut-in voltage VGH2 is by the value change of peripheral divider resistance
Adjust；Change-over circuit 2, its described charge pump circuit 1 of connection and the booster circuit 3, for switching output the
One gate turn-on voltage VGH1 or second grid cut-in voltage VGH2.
Wherein, booster circuit 3 is with charge pump circuit 1 and deposits, and booster circuit 3 is by peripheral divider resistance
Pull-up resistor Ra, the value of pull down resistor Rb determine gate turn-on voltage according to equation below：
It is allowed to output voltage to reach accurate adjustable pattern to provide the cut-in voltage needed for TFT gate switch.For example：
In the case of using 35V as gate turn-on voltage, if the feedback voltage FB of boost module IC2 is
Then pull-up resistor Ra=126.9K during 1.25V, is just capable of achieving during pull down resistor Rb=4.7K.By to grid electricity
The monitor in real time of stream, (can set the thresholding of 5-10mA) when panel consumption grid current is less and now select electricity
Lotus pump IC1 provide gate turn-on voltage for panel.And work as electric current and rise to 10-20mA or so and constantly switch to liter
Die block IC2 provide gate turn-on voltage for panel.
The general wide in range adjustable load capacity of 3 output voltage of booster circuit is strong and transformation efficiency can reach 80%-85%
Left and right, is well suited for the situation higher to gate turn-on voltage and current requirements.Change-over circuit 2 passes through three PMOS
Pipe Q1, Q2, Q3 make with unification difference amplifier U1, doubleway output voltage comparator U2A, a U2B
For switching of the switch to charge pump circuit 1 and booster circuit 3, coordinate different output requirements.
As shown in figure 1, the change-over circuit 2 includes：First switch unit, controls to open the first grid
Voltage VGH1 is exported to the liquid crystal panel；Second switch unit, controls the second grid cut-in voltage
VGH2 is exported to the liquid crystal panel.
Wherein, first switch unit includes the first p-type metal-oxide-semiconductor Q1, the second p-type metal-oxide-semiconductor Q2, second switch unit
Including the 3rd p-type metal-oxide-semiconductor Q3；First and second p-type metal-oxide-semiconductor Q1, Q2 conducting, the 3rd p-type metal-oxide-semiconductor Q3
Close, the in running order output first grid cut-in voltage VGH1 of the charge pump circuit 1 and the liter
Volt circuit 3 is in off working state；Described first and second p-type metal-oxide-semiconductor Q1, Q2 are closed, the 3rd p-type MOS
Pipe Q3 is turned on, and the charge pump circuit 1 is in off working state 3 in running order output of the booster circuit
The second grid cut-in voltage VGH2.
Wherein, the charge pump circuit 1 includes storage capacitor unit and diode, and which is in driving switch
The first grid cut-in voltage VGH1 is pumped out under alternating action.
Wherein, the storage capacitor unit be the first storage capacitor CFLY, the second storage capacitor Cout, first
The negative pole of diode D1 connects the positive pole of the second diode D2, and the first storage capacitor CFLY is connected on charge pump IC1
DRVP ports and the first diode D1 negative poles between；；Second storage capacitor Cout connects charge pump circuit
Output and GND between, the 5th resistance R5 mono- termination the second diode D2 negative poles one termination charge pump IC1
FBP ports；The termination GND of FBP ports one of termination charge pumps IC1 of the 6th resistance R6 mono-.
Wherein, the change-over circuit 2 is specifically included：The first p-type metal-oxide-semiconductor Q1 source electrodes connect charge pump IC1
SUPP ports, drain electrode connects the positive pole of the first diode D1, and grid connects the reverse of second voltage comparator U2B
End；Sampling resistor Rs mono- terminates the negative pole of the second diode D2 and one end of second resistance R2, another termination
One end of first resistor R1；The other end of the other end of second resistance R2 and first resistor R1 connects difference respectively
The positive input and reverse input end of amplifier U1；Feedback resistance Rf is connected on the difference amplifier U1's
Between positive input and outfan；3rd resistor R3 be connected on the difference amplifier U1 reverse input end and
Between GND；The outfan for just terminating the difference amplifier U1 of first voltage comparator U2A；Second is electric
The output of pressure comparator U2B terminates the reverse of the grid and first voltage comparator U1 of the second p-type metal-oxide-semiconductor Q2
End, source electrode are connect between sampling resistor Rs and first resistor R1, and drain electrode output is to panel；3rd p-type MOS
The grid of pipe Q3 connects the outfan of the second voltage comparator U2B, and source electrode meets the SUPP of charge pump IC1
Port, drain electrode connect the VIN ports of boost module IC2.
Wherein, the booster circuit 3 includes：Boost module IC2, its input capacitance Cin are connected on described liter of pressing mold
Between the VIN ports of block and GND；Inductance L is connected between the VIN ports and LX ports of the boost module IC2；
The LX ports of boost module 3 described in the positive pole of the 3rd diode D3, negative pole connect one end of pull-up resistor Ra and output
To panel；Pull down resistor Rb is connected between the FB ports of the boost module 3 and GND；Output capacitance Co is connected on institute
State between the negative pole and GND of the 3rd diode D3.
In Fig. 1, AVDD is produced by PMIC booster circuits 3.VGH1 is produced by charge pump circuit 1, VGH2
Produced by booster circuit 3.The different of electric current are consumed according to panel and output are selected to panel.First p-type MOS
Pipe Q1 connects the input of AVDD and charge pump IC1.Second p-type metal-oxide-semiconductor Q2 connects VGH1 to panel.
Rs is output current sampling resistor Rss of the VGH1 to panel.When gate turn-on voltage and the electric current of panel demand
When smaller, difference amplifier U1 samples the pressure drop on Rs as current detection circuit (calculus of differences)
It is smaller, difference is made by the reasonable value to first resistor R1, second resistance R2, feedback resistance Rf value
The value of the output (i.e. the forward end of voltage comparator first voltage comparator U2A) of amplifier U1 is less than first
The backward end ref1 of voltage comparator U2A, makes first voltage comparator U2A output low levels and less than second
The reference voltage ref2 of voltage comparator U2B, such first p-type metal-oxide-semiconductor Q1, the second p-type metal-oxide-semiconductor Q2
All turn on, the 3rd p-type metal-oxide-semiconductor Q3 shut-off, so since, the in running order output VGH1 of charge pump
Boost to panel and do not export.When the output current of panel increases to a certain value, the efficiency of charge pump circuit
Constantly decline, now difference amplifier U1 outputs increase, U2 reversions, the first p-type metal-oxide-semiconductor Q1, the 2nd P
Type metal-oxide-semiconductor Q2 turns off the 3rd p-type metal-oxide-semiconductor Q3 conductings.Now gate turn-on voltage is from charge pump circuit
VGH1 is switched to by the VGH2 of boosting output to panel.
Fig. 2 is charge pump circuit principle schematic of the present invention.As shown in Fig. 2 charge pump circuit is two energy storage
Electric capacity, a pair (or two pairs) Schottky diodes, just can pump out two in the presence of driving switch alternate conduction
Multiplication of voltage, three multiplication of voltages are supplied to the grid of TFT switch.The characteristics of this circuit is circuit peripheral simple structure, device
It is few, it is with low cost.
Its operation principle and circuit structure are described as follows：Internally under the control of clock CLK, in front half period,
When the first p-type metal-oxide-semiconductor Q1 turns off the second p-type metal-oxide-semiconductor Q2 to be turned on, AVDD passes through the first diode D1
First storage capacitor CFLY is charged, and the first storage capacitor CFLY charging voltages is made to AVDD；In second half
Phase, when the first p-type metal-oxide-semiconductor Q1 turns on the second p-type metal-oxide-semiconductor Q2 to be turned off, SUPP passes through the first p-type
Metal-oxide-semiconductor Q1, the second diode D2, output capacitance Co, the second storage capacitor COUT form loop and store up to first
Energy electric capacity CFLY charges, and according to the characteristic that capacitance voltage can not be mutated, the voltage of the first storage capacitor CFLY can
Maximum is charged to SUPP+AVDD, and now the voltage of VGH is also approximately equal to SUPP+AVDD, by FBP feedback electricity
Pressure benchmark coordinates the regulation of internal error amplifier, the voltage of VGH try to achieve by below equation：
GH=FBP (the 6th resistance R6 of the 5th resistance R5/ of 1+).
Fig. 3 is booster circuit principle schematic of the present invention.As shown in figure 3, inputs of the VIN for booster circuit,
LX is the drain electrode of internal switch pipe, and FB is feedback voltage, and GND is ground.L be an inductance, input capacitance
CIN and output capacitance Co are respectively input into and output capacitance, and D is fly-wheel diode, and pull-up resistor Ra is with
Pull-up resistor Rb is the upper pull down resistor for adjusting output voltage respectively.Its boosting operation principle be：Work as internal switch
Pipe is turned on, outside inductance L accumulation of energys, and fly-wheel diode cut-off, while output capacitance is to load discharge；When interior
When portion's switch is opened, inductance L is charged to output capacitance to load discharge simultaneously by the 3rd diode D3 of afterflow.
By regulated output voltage under the cooperation of the feedback voltage FB regulation of switch and PWM controller internally.
Another embodiment of the present invention proposes a kind of liquid crystal panel drive circuit, and which includes one for driving liquid crystal surface
The drive integrated circult of plate, the drive integrated circult include a voltage conversion circuit, the voltage conversion circuit with it is upper
The structure for stating embodiment is identical, will not be described here.
Further embodiment of this invention proposes a kind of liquid crystal display, and which includes a liquid crystal panel and a liquid crystal panel
Drive circuit, running voltage and work of the liquid crystal panel drive circuit for needed for the liquid crystal panel provides normal work
Make signal, which includes one for producing the running voltage and working signal drive integrated circult, the integrated electricity of the driving
Road includes a voltage conversion circuit, and the voltage conversion circuit is identical with the structure of above-described embodiment, and here is no longer gone to live in the household of one's in-laws on getting married
State.
The present invention propose it is a kind of produce gate turn-on voltage booster circuit 3 is with charge pump circuit 1 and deposits, boost
Circuit 3 by the reasonable value to peripheral divider resistance (Ra, Rb) be allowed to output voltage reach it is accurate adjustable
Pattern come provide TFT gate switch needed for cut-in voltage VGH2.By the monitor in real time to grid current,
Charge pump circuit 1 is selected to provide gate turn-on voltage VGH1 for panel during small current.Liter is switched to during high current
Volt circuit 3 provides gate turn-on voltage VGH2 for panel.Due to general booster circuit output voltage is wide in range can
Adjust load capacity by force and transformation efficiency can reach 80%-85% or so, being well suited for will to gate turn-on voltage and electric current
Seek higher situation.Charge pump circuit 1 and booster circuit 3 are switched by change-over circuit 2.
The present invention be suitable for sizes panel to TFT gate open required for magnitude of voltage, electric charge pump module and
Boost module flexibly switches according to the detection to grid current, reduces circuit power consumption to greatest extent and improves turning for system
Change efficiency.
The undeclared part that is related in the present invention is same as the prior art or is realized using prior art.Should
Point out：To those of ordinary skill in the art, under the premise without departing from the principles of the invention, every
Any simple modification, change and the equivalent structure change substantially above example made according to the technology of the present invention,
Belong in the protection domain of technical solution of the present invention.
Claims (7)
1. a kind of voltage conversion circuit, which includes：
Charge pump circuit, the charge pump circuit are a condenser type adjustment circuit, the pulse signal of its return pulse signal generating meanss output, and carry out pressure regulation and rectification process to the pulse signal, so as to export first grid cut-in voltage；
Booster circuit, for exporting second grid cut-in voltage, the big I of amplitude of the second grid cut-in voltage is changed by the value of peripheral divider resistance and is adjusted；
Change-over circuit, which connects the charge pump circuit and the booster circuit, for switching output first grid cut-in voltage or second grid cut-in voltage；
Also include that the voltage conversion circuit exports first and second gate turn-on voltage to liquid crystal panel, when electric current is less than the reference value of the liquid crystal panel grid current, the change-over circuit switches to the charge pump circuit and exports the first grid cut-in voltage, when electric current is more than the reference value of the liquid crystal panel grid current, the change-over circuit switches to the booster circuit and exports the second grid cut-in voltage；
The change-over circuit includes：
First switch unit, control export the first grid cut-in voltage to the liquid crystal panel；
Second switch unit, control export the second grid cut-in voltage to the liquid crystal panel；
The change-over circuit includes：
First switch unit includes the first p-type metal-oxide-semiconductor, the second p-type metal-oxide-semiconductor, and second switch unit includes the 3rd p-type metal-oxide-semiconductor；
First and second p-type metal-oxide-semiconductor conducting, the 3rd p-type metal-oxide-semiconductor are closed, the charge pump circuit in running order output first grid cut-in voltage and the booster circuit is in off working state；
The first and second p-type metal-oxide-semiconductor is closed, the 3rd p-type metal-oxide-semiconductor conducting, and the charge pump circuit is in the off working state booster circuit in running order output second grid cut-in voltage.
2. such as claim 1
- described voltage conversion circuit, it is characterised in that：The condenser type adjustment circuit includes storage capacitor unit and diode, and which pumps out the first grid cut-in voltage under the alternating action of driving switch.
3. such as claim
Voltage conversion circuit described in 2, it is characterised in that：The storage capacitor unit is the first storage capacitor, the second storage capacitor, and the negative pole of the first diode connects the positive pole of the second diode, and the first storage capacitor is connected between the DRVP ports of charge pump circuit and first diode cathode；Second storage capacitor is connect between the output of charge pump circuit and GND；
Termination the second diode cathode one of 5th resistance one terminates the FBP ports of charge pump circuit；
The termination GND of FBP ports one of the termination charge pump circuit of the 6th resistance one.
4. such as claim
Voltage conversion circuit described in 3, it is characterised in that：The change-over circuit is specifically included：
The first p-type metal-oxide-semiconductor source electrode connects the SUPP ports of charge pump circuit, and drain electrode connects the positive pole of the first diode, and grid connects the backward end of second voltage comparator；
Sampling resistor one terminates the negative pole of the second diode and one end of second resistance, one end of another termination first resistor；
The other end of the other end of second resistance and first resistor connects the reverse input end and positive input of difference amplifier respectively；
Feedback resistance is connected between the positive input and outfan of the difference amplifier；
3rd resistor is connected between the reverse input end and GND of the difference amplifier；
The outfan for just terminating the difference amplifier of first voltage comparator；The grid and the backward end of second voltage comparator of the output second p-type metal-oxide-semiconductor of termination of first voltage comparator, the source electrode of the second p-type metal-oxide-semiconductor are connect between sampling resistor and first resistor, and drain electrode output is to panel；
The grid of the 3rd p-type metal-oxide-semiconductor connects the outfan of the second voltage comparator, and source electrode connects the SUPP ports of charge pump circuit, and drain electrode connects the VIN ports of booster circuit.
5. such as claim
3
Or
Voltage conversion circuit described in 4, it is characterised in that：The booster circuit includes：
Boost module, input capacitance are connected between the VIN ports of the boost module and GND；
Inductance is connected between the VIN ports of the boost module and LX ports；
The LX ports of boost module described in the positive pole of the 3rd diode, negative pole connect one end of pull-up resistor and export to panel；
Pull down resistor is connected between the FB ports of the boost module and GND；
Output capacitance is connected between the 3rd diode cathode and GND.
6. a kind of liquid crystal panel drive circuit, which includes one for driving the drive integrated circult of liquid crystal panel, and the drive integrated circult includes a voltage conversion circuit, it is characterised in that：The voltage conversion circuit is claim
1
Extremely
Voltage conversion circuit in 5 described in any one.
7. a kind of liquid crystal display, which includes a liquid crystal panel and a liquid crystal panel drive circuit, running voltage and working signal of the liquid crystal panel drive circuit for needed for the liquid crystal panel provides normal work, which includes one for producing the running voltage and working signal drive integrated circult, the drive integrated circult includes a voltage conversion circuit, it is characterised in that：The voltage conversion circuit is claim
1
Extremely
Voltage conversion circuit in 5 described in any one.
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| CN201410480146.0A CN104200790B (en) | 2014-09-18 | 2014-09-18 | Voltage switching circuit, liquid crystal panel drive circuit and liquid crystal display |
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| CN201410480146.0A CN104200790B (en) | 2014-09-18 | 2014-09-18 | Voltage switching circuit, liquid crystal panel drive circuit and liquid crystal display |
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| CN104200790B true CN104200790B (en) | 2017-03-22 |
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| CN105405423B (en) | 2015-12-15 | 2019-01-15 | 深圳市华星光电技术有限公司 | Gate drive apparatus and its array substrate |
| CN105810172A (en) * | 2016-05-31 | 2016-07-27 | 京东方科技集团股份有限公司 | Display driving circuit and display device |
| CN106027012B (en) * | 2016-06-13 | 2023-05-05 | 达凯(上海)电子科技有限公司 | Pull-down resistor switch circuit |
| CN107706906A (en) * | 2017-11-21 | 2018-02-16 | 深圳市京泉华科技股份有限公司 | Anti-back flow circuit and power supply redundancy circuit |
| CN108962119B (en) * | 2018-08-01 | 2021-11-02 | 京东方科技集团股份有限公司 | Level shift circuit, driving method thereof and display device |
| CN109256103A (en) * | 2018-11-09 | 2019-01-22 | 惠科股份有限公司 | Driving circuit of display device |
| CN109410883A (en) | 2018-12-27 | 2019-03-01 | 惠科股份有限公司 | Boost circuit of display panel, boost control method and display device |
| CN110311556B (en) * | 2019-06-27 | 2020-08-04 | 南京中电熊猫液晶显示科技有限公司 | Power module, power control circuit and method for improving insufficient discharge of display panel |
| CN110767195B (en) * | 2019-11-20 | 2022-07-01 | 京东方科技集团股份有限公司 | Display device and driving method thereof |
| CN112002290A (en) * | 2020-09-22 | 2020-11-27 | 浙江鸿泉电子科技有限公司 | Liquid crystal display pixel point display voltage providing device |
| CN112994436B (en) * | 2021-02-04 | 2022-06-03 | 重庆先进光电显示技术研究院 | Grid opening voltage generation circuit, display panel driving device and display device |
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| CN112927662B (en) * | 2021-03-09 | 2022-08-05 | 重庆惠科金渝光电科技有限公司 | Driving method and driving circuit of display panel |
| CN113205783B (en) * | 2021-04-25 | 2022-11-25 | 成都中电熊猫显示科技有限公司 | Control apparatus for display device and control method for level conversion module |
| CN113643652B (en) * | 2021-08-05 | 2022-10-14 | 深圳市合科泰电子有限公司 | Drive chip with built-in charge pump |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001272959A (en) * | 2000-03-28 | 2001-10-05 | Casio Comput Co Ltd | Liquid crystal display device |
| KR101061855B1 (en) * | 2004-10-01 | 2011-09-02 | 삼성전자주식회사 | Driving voltage generation circuit and display device including same |
| DE102005019256A1 (en) * | 2005-04-26 | 2006-11-16 | Texas Instruments Deutschland Gmbh | Bias power supply for liquid crystal display, has voltage amplifier with several charge pump stages, where one stage comprises reference potential that is based on output signal of DC to DC converter |
| CN201365305Y (en) * | 2009-02-05 | 2009-12-16 | 青岛海信电器股份有限公司 | Power supply management circuit and television equipped therewith |
| KR101055916B1 (en) * | 2009-09-16 | 2011-08-09 | 하이디스 테크놀로지 주식회사 | LCD display driving circuit |
-
2014
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