CN209471733U

CN209471733U - A kind of liquid crystal display bias power supply circuit

Info

Publication number: CN209471733U
Application number: CN201920378094.4U
Authority: CN
Inventors: 王洪
Original assignee: Hunan Diwen Technology Co Ltd
Current assignee: Hunan Diwen Technology Co Ltd
Priority date: 2019-03-22
Filing date: 2019-03-22
Publication date: 2019-10-08
Anticipated expiration: 2029-03-22

Abstract

The utility model relates to a kind of liquid crystal display bias power supply circuits, include switching circuit, AVDD voltage circuit, VCOM potential circuit, VGL potential circuit and VGH potential circuit；The AVDD voltage circuit is connected with switching circuit, and the VCOM potential circuit is connected with AVDD voltage circuit, and the VGL is connected with switching circuit, and the VGH is connected with switching circuit；The software closed-loop control to switching circuit is formed by PWM pulse-width signal and IFB analog quantity voltage feedback signal, last and different component of arranging in pairs or groups makes accurately voltage control, to provide simple, stable, reliable, versatile liquid crystal display bias power supply circuit.

Description

A kind of liquid crystal display bias power supply circuit

Technical field

The utility model relates to technical field of integrated circuits, and in particular to a kind of liquid crystal display bias power supply circuit.

Background technique

With the development of industrial agricultural and science and technology, the continuous improvement of living standards of the people is more and more colored Liquid crystal display occurs in the daily life of the people, and color LCD screen provides colored information more and more for the mankind and mentions Show.

What is be most widely used at present in current social is TFT color LCD screen；TFT (ThinFilmTransistor) is Refer to thin film transistor (TFT), imply that each liquid crystal pixel point be driven by being integrated in the subsequent thin film transistor (TFT) of pixel, thus It can accomplish high speed, high brightness, high contrast display screen information, be one of LCD color display apparatus best at present, Effect is the mainstream display device on present Laptop & Desktop close to CRT monitor.Each pixel of TFT It is to be controlled by TFT integrated on itself, is active pixel.Therefore, not only speed can be greatly improved, and contrast It is also substantially increased with brightness, while resolution ratio has also reached high level.

Meanwhile TFT color LCD screen is while having many advantages, such as, it is also necessary to reliable and stable driving circuit, wherein It just include the circuit of liquid crystal display bias supply, since the circuit needs the fluctuation of multiple voltage and the circuit to will cause display Effect is impacted, therefore the reliable and stable content for becoming developer and being extremely concerned about of the bias power supply circuit of liquid crystal display.But Current liquid crystal screen bias supply often uses the additional mating capacitance resistance ware of outsourcing driving chip to realize, but the program can be limited by The driving chip of outsourcing, program cost is not only high but also driving chip stops production or liquid crystal display change is often made again if encountered It is unsatisfactory for requiring to re-replace driving chip again at driving chip, will cause the stability decline and product versatility of product It is not strong；The extension and development amount that will also result in developer's development cycle simultaneously increase.

Utility model content

The technical problem to be solved by the utility model is to provide a kind of simple, stable, reliable, low in cost, versatilities Strong liquid crystal display bias power supply circuit.

The technical solution that the utility model solves above-mentioned technical problem is as follows: liquid crystal display bias power supply circuit includes switch Circuit, AVDD voltage circuit, VCOM potential circuit, VGL potential circuit and VGH potential circuit；The AVDD voltage circuit with Switching circuit is connected；The VCOM potential circuit is connected with AVDD voltage circuit；The VGL is connected with switching circuit； The VGH is connected with switching circuit.

The switching circuit includes capacitor C22, capacitor C2, inductance L1, N-MOS pipe M1, resistance R17, resistance R18 and electricity Hold C15；Capacitor C22 is connected with capacitor C2 parallel connection, and connection type is consistent, and one end of capacitor C22 and capacitor C2 connect electricity Source inputs VCC-IN connection, also connect with one end of inductance L1, the other end of capacitor C22 and capacitor C2 are connected with GND； The other end of inductance L1 is connected with the pole D of N-MOS M1；The one end resistance R17 is connected with the pole G of N-MOS, and in addition one End is connected with GND；The one end resistance R18 is connected with the pole D of N-MOS, and other end is connected with one end of capacitor C15；Electricity The one end for holding C15 is connected with resistance R18, and the other end is connected with GND.

Capacitor C22 and capacitor C2, two capacitors are the front-end filtering for being linked into the functional circuit, decoupling capacitance, really Protecting the functional circuit, just clutter energy that is clean enough and this functional circuit not being generated passes in power input status Lead remaining circuit.

Further, capacitor C22 and capacitor C2 should be abutted against the end inductance L1 nearby；

Further, capacitor C22 value range is 10uF~470uF；

Further, capacitor C2 value range is 10pF~470pF；

Do so have the beneficial effect that capacitor C22 stabilize the liquid crystal display bias power supply circuit voltage fluctuation, can also be with Acted on as energy accumulation of energy, the value of capacitor C2 also filtered the High-frequency Interference of power supply power supply, while also solve high frequency for The injury of capacitor C22 extends the service life of large bulk capacitance C22.

The AVDD voltage circuit contains diode D13, capacitor C1, capacitor C18, resistance R13, resistance R1；Two poles The pole D of the anode connection N-MOS of pipe, one end of the cathode connection capacitor C1 of diode；Capacitor C1 is with capacitor C18 using in parallel Connection type, connection type are consistent, and capacitor C1 connect the cathode of diode D13 with one end of capacitor C18, capacitor C1 with The other end of capacitor C18 connects GND；The one end resistance R13 is connect with the cathode of diode D13, other end and resistance R1 phase Connection；One end of resistance R1 is connected with resistance R13, and other end is connected with GND.

Inductance L1 and N-MOS pipe M1 and diode D13 constitute booster circuit, which can be the electricity of power supply Pressure VCC-IN boosts to the voltage value of circuit configuration, has carried out function for subsequent VGH voltage with, AVDD voltage and VCOM voltage It can prepare.

Further, inductance L1 value range is 3.3uH~220uH；

Further, N-MOS pipe M1 recommends using models such as SK341, AO3414, RSR06N06L；

Further, diode D13 recommends using models such as SS14, SS34, SS36,1N4148；

Having the beneficial effect that of designing in this way can be can produce higher by the inductance of L1 under low PWM drive signal Energy stores are that the voltage of boosting is prepared；The reason of N-MOS pipe uses S4341 is low for the N-MOS internal resistance resistance value, pressure voltage Height can generate higher boost voltage in very low energy loss；Diode D13 value is SS14, two pole The voltage and electric current that pipe can rectify out close to 40V reach as high as 1A, since liquid crystal display bias voltage power supply rarely exceeds 40V So the liquid crystal display bias voltage demand of various different models can be effectively compatible with.

The effect of capacitor C1, C18 are the AVDD voltage after filtering, stable boosting, and AVDD voltage stabilization is allowed to set at one Fixed voltage value, at the same capacitor C1 can filter boosting generate high-frequency noise, and can protect large bulk capacitance C18 from High frequency damage.

Resistance R13 and R1 are connected in parallel between AVDD and GND, and IFB function electricity is drawn among resistance R13 and R1 Pressure；Resistance R13 and R1 are the detection feedbacks as AVDD, can be real-time to the analog detection end of single-chip microcontroller by IFB feedback Detect the modulation whether voltage of AVDD has deviation then to carry out pwm signal.

Further, resistance R13 value range is 1K Ω~100K Ω；

Further, resistance R1 value range is 1K Ω~100K Ω；

Having the beneficial effect that for designing in this way exports a stable AVDD voltage value by capacitor C1 and C18, then passes through The partial pressure effect of resistance R13 and R1 generate IFB and detect feedback signal, by the voltage value of IFB real-time detection AVDD, if not It is expected voltage value, the duty ratio by adjusting PWM is the AVDD voltage value of adjustable output；Thus by IFB and PWM forms a closed-loop control system.

The VCOM potential circuit includes resistance R14, capacitor C19 and resistance R15；One end of resistance R14 and resistance R13 is connected, and other end is connected with one end of capacitor C19；The one end capacitor C19 is connected with resistance R14, other end with Resistance R15 is connected；The one end resistance R15 is connected with resistance R14, and other end is connected with GND；The resistance R14 value Range is 1K Ω~100K Ω, and the capacitor C19 value range is 10uF~470uF, and the resistance R15 value range is 1K Ω ~100K Ω.

The VGL potential circuit includes diode D1, capacitor C23, diode D10, resistance R2, capacitor C16, capacitor C20, voltage-stabiliser tube D12, resistance R16；The cathode of the cathode of the cathode connecting diode D13 of diode D1, diode D1 connects electricity Hold one end of C23；The one end capacitor C23 is connected with diode D1, and other end is connected with the pole D of N-MOS pipe；Diode Positive one end of D10 is connect with one end of capacitor C23, and other end is connected with one end of resistance R2；One end resistance R2 and two The cathode of pole pipe D10 connects, and other end is connected with capacitor C16；Capacitor C16 and capacitor C20, voltage-stabiliser tube D12 and resistance R16 is parallel relationship, their connection type is that the side of capacitor C16, C20, the cathode of voltage-stabiliser tube and resistance R16 are connected to On resistance R1, other end is all connected on GND.

Capacitor C23, diode D1 and D10 form a two voltage-doubling boost circuits, and the output of VGH is allowed to generate higher electricity Pressure.

Further, capacitor C23 value range is 1nF~1000nF；

Further, diode D1 selection model is recommended as SS14, SS34, SS36,1N4148 etc.；

Further, diode D10 selection model is recommended as SS14, SS34, SS36,1N4148 etc.；

Having the beneficial effect that for designing in this way forms two voltage-multiplying circuits by capacitor C23, diode D1 and D10, this Sample does the voltage value that can be effectively lifted VGH, and VGH needs+15~+30V or so under normal conditions, and directly to pass through electricity The so high voltage value of sense, the generation of N-MOS pipe would generally promote the pressure voltage of other devices.Therefore pass through two times of piezoelectricity Road, which generates VGH voltage, is a kind of very simple and effective method.

Further, resistance R2 and resistance R16 can not only divide two multiplication of voltage values of generation but also can limit VGH Output electric current；

Further, capacitor C16 and capacitor C20 can filter the VGH voltage value of generation, allow VGH output voltage stabilization；

Further, voltage-stabiliser tube D12 can allow VGH to be directly limited in the voltage value of the wanted pressure stabilizing of voltage-stabiliser tube D12, and doing so can With voltage needed for being accurately controlled VGH, different liquid crystal displays for the voltage of VGH can small-scale difference, so logical The pressure clamping action of the pressure stabilizing and voltage-stabiliser tube of crossing steady resistance R2 and R16 changes the voltage of VGH.

The beneficial effect done so is: VGH voltage in liquid crystal display bias supply can simply by three devices into Row modification, without juggling things greatly to circuit progress is additional.

On this basis further, resistance R2 value range is 1K Ω~100K Ω；

Further, resistance R16 value range is 1K Ω~100K Ω；

The value range that further voltage-stabiliser tube D12 value range is the such VGH of 2V~40V has just been limited to 2V~40V.

Further, capacitor C16 and C20 can be used as the filtering and stabilization of VGH, make the voltage of VGH more stable；

Further, capacitor C16 value range is 10pF~470pF；

Further, capacitor C20 value range is 10uF~470uF；

Having the beneficial effect that for doing so makes the voltage output of VGH more stable, does not fluctuate.

The VGH potential circuit includes capacitor C24, diode D11, diode D9, resistance R19, capacitor C17, capacitor C21, voltage-stabiliser tube D14, resistance R20；Capacitor C24 is connected with the pole D of N-MOS pipe, the cathode phase of other end and diode D11 Connection, the one end diode D11 are connect with one end of capacitor C24, and other end is connected with one end of resistance R19；Diode D9 One end is connected with capacitor C24, and other end is connected with GND；The one end resistance R219 is connect with the anode of diode D11, separately Outer one end is connected with capacitor C17；Capacitor C17 and capacitor C21, voltage-stabiliser tube D14 and resistance R20 are parallel relationships, they Connection type is that the side of capacitor C17, C21, the anode of voltage-stabiliser tube and resistance R20 are connected on resistance R19, and other end is all It is connected on GND.

Capacitor C24, diode D9 and D11 form negative voltage rectified output structure circuit, and design can be direct in this way Negative electricity laminate section is taken out, to generate VGL voltage needed for liquid crystal display bias power supply circuit, passes through resistance R19 at the same time And the electric resistance partial pressure of R20 can further decrease VGL voltage, clamper VGL voltage can forced to surely by voltage-stabiliser tube D14 In the voltage at pressure pipe both ends, and the smoothened stabilization of VGL fluctuation voltage is allowed by the cooperation of capacitor C17 and capacitor C21.

Further, capacitor C24 value range is 1nF~1000pF；

Further, diode D9 and D11 selection model is recommended as SS14, SS34, SS36,1N4148 etc.；

Further, resistance R19 and R20 value range are 1K Ω~100K Ω；

Further, voltage-stabiliser tube D14 value range is 2V~40V；

Further, capacitor C17 value range is 10pF~1000pF；

The beneficial effect done so is: can be built needed for liquid crystal display bias supply using very common component VGL voltage；And it is suitable to facilitate can to modify the voltage value of VGL simply by the pressure stabilizing value of modification voltage-stabiliser tube D14 Answer VGL voltage value different needed for the liquid crystal display of different model.

Detailed description of the invention

Fig. 1 is the utility model electrical block diagram.

Specific embodiment

The principles of the present invention and feature are described below in conjunction with attached drawing, example is served only for explaining that this is practical It is novel, it is not intended to limit the scope of the utility model.

As shown in Figure 1, the input of liquid crystal display bias supply includes capacitor C22 and capacitor C2, which is to be linked into Front-end filtering, the decoupling capacitance of the functional circuit, it is ensured that the functional circuit in power input status just enough completely with And not the clutter energy conduction of this functional circuit generation to remaining circuit.

Further, capacitor C22 and capacitor C2 are connected in parallel；A termination power input VCC-IN in parallel, the other end Meet GND；

Further, mono- termination capacitor C2 of inductance L1, the pole D of another termination N-MOS.

Further, the pole G of N-MOS pipe connects pwm signal source；

Further, a pull down resistor R17 is also matched in the pole G of N-MOS pipe；

Further, resistance R17 mono- terminates extremely another termination GND. of G of N-MOS

It is made of simultaneously one group of RC circuit R18 and C15, which can have to N-MOS pipe due to on-off action It is buffered.

Further, the resistance R18 mono- in RC circuit terminates the pole D of N-MOS pipe M1, the capacitor in another termination RC circuit The one end C15；

Further, C15 mono- terminates one end of R18, another termination GND.

Further, capacitor C1 is with capacitor C18 by the way of in parallel；

Further, the cathode of one end connection diode D13 of capacitor C1, another termination GND；

Further, the pole D of mono- end Jie N-MOS of rectifier diode D14, other end connect one end of capacitor C1.

Further, the one end resistance R13 is connected to the cathode of diode D14, and other end is connected to one end of R1；

Further, the one end resistance R1 is connected to one end of resistance R13, and other end meets GND.

Further, the one end capacitor C23 is connected to the cathode of D1, and other end is connected to the pole D of N-MOS；

Further, the cathode other end that the one end diode D1 is connected to D13 is connected to one end of C23；

Further, one end other end that the one end diode D10 is connected to C23 is connected to one end of R2；

Further, one end of resistance R2 is connected to the cathode other end connection capacitor of D10 in one end of C16；

Further, the one end resistance R16 is connected to one end of resistance R2, and other end meets GND；

Further, one end of capacitor C16 is connected to one end of resistance R2, and other end meets GND；

Further, capacitor C20 is consistent with capacitor C16 therefore connection type in parallel；

Further, voltage-stabiliser tube D12 can allow VGH to be directly limited in the voltage value of the wanted pressure stabilizing of voltage-stabiliser tube D12, and doing so can With voltage needed for being accurately controlled VGH, different liquid crystal displays for the voltage of VGH can small-scale difference, so logical The pressure clamping action of the pressure stabilizing and voltage-stabiliser tube of crossing steady resistance R2 and R12 changes the voltage of VGH.

Further, one end of the cathode connecting resistance R16 of voltage-stabiliser tube D12, anode meet GND.

Further, the pole the D other end of the one end capacitor C24 connection N-MOS is connected to the cathode of D11；

Further, the anode of diode D11 is connected to one end of resistance R19；

Further, the other end of resistance R19 is connected to one end of capacitor C17；

Further, the other end of capacitor C17 meets GND；

Further, the anode of diode D9 connects one end of capacitor C24, and anode meets GND；

Further, capacitor C17 is that therefore connection type is consistent for paralleling model with capacitor C21；

Further, the anode of voltage-stabiliser tube D14 connects one end of capacitor C21, and cathode meets GND

Further, resistance R20 is consistent using therefore connection type in parallel with capacitor C21；

The above is only the preferred embodiment of the present invention, is not intended to limit the utility model, all practical at this Within novel spirit and principle, any modification, equivalent replacement, improvement and so on should be included in the guarantor of the utility model Within the scope of shield.

Claims

1. a kind of liquid crystal display bias power supply circuit, it is characterised in that include switching circuit, AVDD voltage circuit, VCOM voltage electricity Road, VGL potential circuit and VGH potential circuit；The AVDD voltage circuit is connected with switching circuit, the VCOM voltage electricity Road is connected with AVDD voltage circuit, and the VGL is connected with switching circuit, and the VGH is connected with switching circuit.

2. a kind of liquid crystal display bias power supply circuit as described in claim 1, which is characterized in that the switching circuit contains electricity Hold C22, capacitor C2, inductance L1, N-MOS pipe M1, resistance R17, resistance R18 and capacitor C15；Capacitor C22 is in parallel with capacitor C2 It is connected, one end of capacitor C22 and capacitor C2 connect power input VCC-IN connection, also it connect with one end of inductance L1, The other end of capacitor C22 and capacitor C2 are connected with GND；The other end of inductance L1 is connected with the pole D of N-MOS M1；Electricity Resistance one end R17 is connected with the pole G of N-MOS, and other end is connected with GND；The one end resistance R18 is extremely connected with the D of N-MOS It connects, other end is connected with one end of capacitor C15；One end of capacitor C15 is connected with resistance R18, and the other end is connected with GND It connects.

3. a kind of liquid crystal display bias power supply circuit according to claim 2, which is characterized in that the capacitor C22 value model Enclose for 10uF~470uF, the capacitor C2 value range is 10pF~1000pF, the inductance L1 value range be 3.3uH~ 220uH, the N-MOS pipe M1 recommend to choose model 3K341, AO3414, RSR060N06L etc., the resistance R17 value model Enclose for 1K Ω~100K Ω, the resistance R18 value range is 1 Ω~10K Ω, the capacitor C15 value range be 10pF~ 1000pF。

4. a kind of liquid crystal display bias power supply circuit as described in claim 1, which is characterized in that the AVDD voltage circuit packet Diode D13, capacitor C1, capacitor C18, resistance R13, resistance R1 are contained；The pole D of the anode connection N-MOS of diode, diode Cathode connection capacitor C1 one end；Capacitor C1 uses connection type in parallel with capacitor C18, and connection type is consistent, Capacitor C1 connect the cathode of diode D13 with one end of capacitor C18, and capacitor C1 connect GND with the other end of capacitor C18；Electricity Resistance one end R13 is connect with the cathode of diode D13, and other end is connected with resistance R1；One end of resistance R1 and resistance R13 phase Connection, other end are connected with GND.

5. a kind of liquid crystal display bias power supply circuit according to claim 4, which is characterized in that the diode D13 chooses Model is recommended as SS14, SS34, SS36,1N4148 etc., and the capacitor C1 value range is 10pF~1000pF, the capacitor C18 value range is 10uF~470uF, and the resistance R13 value range is 1K Ω~100K Ω, the resistance R1 value range For 1K Ω~100K Ω.

6. a kind of liquid crystal display bias power supply circuit as described in claim 1, which is characterized in that the VCOM potential circuit packet Resistance R14, capacitor C19 and resistance R15 are contained；One end of resistance R14 is connected with resistance R13, other end and capacitor C19 One end be connected；The one end capacitor C19 is connected with resistance R14, and other end is connected with resistance R15；The one end resistance R15 with Resistance R14 is connected, and other end is connected with GND；The resistance R15 value range is 1K Ω~100K Ω, the capacitor C19 value range is 10uF~470uF, and the resistance R14 value range is 1K Ω~100K Ω.

7. a kind of liquid crystal display bias power supply circuit as described in claim 1, which is characterized in that the VGL potential circuit packet Diode D1, capacitor C23, diode D10, resistance R2, capacitor C16, capacitor C20, voltage-stabiliser tube D12, resistance R16 are contained；Two poles The cathode of the cathode connecting diode D13 of pipe D1, one end of the cathode connection capacitor C23 of diode D1；One end capacitor C23 and two Pole pipe D1 is connected, and other end is connected with the pole D of N-MOS pipe；Positive one end of diode D10 and one end of capacitor C23 Connection, other end are connected with one end of resistance R2；The one end resistance R2 is connect with the cathode of diode D10, other end with Capacitor C16 is connected；Capacitor C16 and capacitor C20, voltage-stabiliser tube D12 and resistance R16 are parallel relationships, their connection type It is that the side of capacitor C16, C20, the cathode of voltage-stabiliser tube and resistance R16 is connected on resistance R1, other end is all connected to GND On.

8. a kind of liquid crystal display bias power supply circuit according to claim 7, which is characterized in that the diode D1 selection type Number it is recommended as SS14, SS34, SS36,1N4148 etc., the capacitor C23 value range is 1nF~1000nF, the diode D10 chooses model and is recommended as SS14, SS34, SS36,1N4148 etc., and the resistance R2 value range is 1K Ω~100K Ω, institute Stating capacitor C16 value range is 10pF~1000pF, and the capacitor C20 value range is 1uF~470uF, the voltage-stabiliser tube D12 Value range is 2V~40V, and the resistance R16 value range is 1K Ω~100K Ω.

9. a kind of liquid crystal display bias power supply circuit as described in claim 1, which is characterized in that the VGH potential circuit packet C24 containing capacitor, diode D11, diode D9, resistance R19, capacitor C17, capacitor C21, voltage-stabiliser tube D14, resistance R20；Capacitor C24 is connected with the pole D of N-MOS pipe, and other end is connected with the cathode of diode D11, the one end diode D11 and capacitor One end of C24 connects, and other end is connected with one end of resistance R19；The one end diode D9 is connected with capacitor C24, in addition One end is connected with GND；The one end resistance R219 is connect with the anode of diode D11, and other end is connected with capacitor C17；Electricity Holding C17 and capacitor C21, voltage-stabiliser tube D14 and resistance R20 is parallel relationship, their connection type is capacitor C17, C21, steady The anode of pressure pipe and the side of resistance R20 are connected on resistance R19, and other end is all connected on GND.

10. a kind of liquid crystal display bias power supply circuit according to claim 9, which is characterized in that the capacitor C24 value model It encloses for 1nF~1000nF, the diode D11 chooses model and is recommended as SS14, SS34, SS36,1N4148 etc., the diode D9 chooses model and is recommended as SS14, SS34, SS36,1N4148 etc., and the resistance R19 value range is 10 Ω~10K Ω, described Capacitor C17 value range is 10pF~1000pF, and the capacitor C21 value range is 1uF~470uF, and the voltage-stabiliser tube D14 takes Value range is 2V~40V, and the resistance R20 value range is 1K Ω~100K Ω.