CN101388986A - Power-on pulse eliminating circuit - Google Patents
Power-on pulse eliminating circuit Download PDFInfo
- Publication number
- CN101388986A CN101388986A CNA2008102166345A CN200810216634A CN101388986A CN 101388986 A CN101388986 A CN 101388986A CN A2008102166345 A CNA2008102166345 A CN A2008102166345A CN 200810216634 A CN200810216634 A CN 200810216634A CN 101388986 A CN101388986 A CN 101388986A
- Authority
- CN
- China
- Prior art keywords
- triode
- power
- capacitor
- circuit
- eliminating circuit
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Landscapes
- Control Of Indicators Other Than Cathode Ray Tubes (AREA)
Abstract
The invention discloses a starting impulse eliminating circuit, which comprises a capacitor C1, a resistor R2 connected to the capacitor C1 in series, a diode D3 and a triode Q3. In which, the positive pole of the capacitor C1 is connected to the power supply 12V, while the negative pole is connected to one end of the resistor R2; the other end of the resistor R2 is connected to the negative pole of the diode D3 and the base electrode of the triode Q3; the positive pole of the diode D3 is connected to the earth; the emitter of the triode Q3 is connected to the earth; the collector of the triode Q3 is connected to the MCU control signal. On the starting moment, the negative pole of the capacitor C1 inducts to a voltage impulse, the voltage impulse is applied on the base electrode of the triode Q3 through the resistor R2 to make the triode Q3 into conduction to compensate the shortage that the port is on high electrical level and can not pull down [BKLT_EN] while the MCU is initialized on the starting moment, consequently, the LVDS_POWER starting impulse is eliminated, and the abnormal screen display problem while starting.
Description
[technical field]
The present invention relates to the circuit engineering field that the liquid crystal TV set system is used to optimize liquid crystal display screen start sequential, particularly a kind of power-on pulse eliminating circuit.
[background technology]
LCD TV has become the main product of TV market at present, and liquid crystal display screen has strict requirement for electrifying timing sequence, if electrifying timing sequence is not right, not abnormal state such as demonstration or Hua Ping of liquid crystal display screen just might occur.Wherein, the electrifying timing sequence of screen T-CON plate power supply is one of them strict project.Prior art adopts circuit shown in Figure 1 to come to the power supply of screen T-CON plate, send control signal " BKLT_EN " by the MCU of liquid crystal television system mainboard and control the conducting of triode Q2 or end, thus the conducting of control P channel MOS tube Q1 or conducting or cut-out between powering with control LVDS_POWER and 12V.Yet, there is shortcoming in the circuit of prior art, LVDS_POWER has a pulse appearance of violating liquid crystal display screen start sequential when exchanging start, as shown in Figure 2, when exchanging start, MCU (A-B period among Fig. 2 in the inner initialized time of beginning, probably be tens to hundreds of ms), its I/O mouth is not controlled and is in default conditions, it is high level, just control signal " BKLT_EN " thus be that high level triode Q2 conducting makes the grid potential of metal-oxide-semiconductor Q1 be lower than source electrode, during this period of time, thereby metal-oxide-semiconductor Q1 is in conducting state LVDS_POWE and 12V conducting, (after the B point) MCU drags down control signal " BKLT_EN " earlier after the MCU initialization finishes, thereby draw high control signal " BKLT_EN " after the every work of the system that treats is ready to again start, LVDS_POWER a pulse of violating the start sequential occurs in the A-B section like this, shields thereby flower usually occurs when causing the liquid crystal display screen start, abnormal states such as no image.
[summary of the invention]
For addressing the above problem, main purpose of the present invention is to provide a kind of power-on pulse eliminating circuit, with avoid the TV MCU system in when start because abnormal states such as flower screen, no image appear in MCU initialization and port is not controlled when causing the liquid crystal display screen start.
For achieving the above object, technical scheme of the present invention is:
A kind of power-on pulse eliminating circuit, the resistance R 2, diode D3 and the triode Q3 that include power supply, capacitor C 1, be connected in series with capacitor C 1; Wherein, the positive pole of described capacitor C 1 is connected to power supply 12V, and the negative pole of capacitor C 1 is connected to an end of resistance R 2; The other end of resistance R 2 is connected to the base stage of negative pole and the triode Q3 of diode D3, the plus earth of diode D3, the grounded emitter of triode Q3, the collector electrode of triode Q3 and MCU control signal with.
Further, the power supply of pulse eliminating circuit is adopted same 12V power supply with screen T-CON plate power-supplying circuit, and the capacitor C 1 of pulse eliminating circuit is connected to the 12V power supply jointly with diode D1, the inductance L 1 of screen T-CON plate power-supplying circuit.
Compared to prior art, power-on pulse eliminating circuit of the present invention is in the moment of start, capacitor C 1 negative pole is sensed a potential pulse, thereby this pulse voltage makes triode Q3 conducting by the base stage that resistance R 2 is added to triode Q3, compensated since during start moment MCU initialization port be high level and can not drag down the deficiency of " BKLT_EN ", thereby eliminated the power-on pulse of LVDS_POWER, solved start flower screen or do not had the problem that thing shows.
[description of drawings]
Fig. 1 is the liquid crystal display screen T-CON plate power-supplying circuit of prior art.
Fig. 2 is signal 12V, BKLT_EN, the LVDS_POWER oscillogram of Fig. 1.
Fig. 3 is the circuit diagram of power-on pulse eliminating circuit of the present invention.
Fig. 4 inserts the diagram of prior art liquid crystal display screen T-CON plate power-supplying circuit for the present invention.
Fig. 5 is the operating voltage oscillogram of Fig. 4 circuit each point.
[embodiment]
See also shown in Figure 3, resistance R 2, diode D3 and triode Q3 that power-on pulse eliminating circuit of the present invention includes capacitor C 1, is connected in series with capacitor C 1.Wherein, the positive pole of described capacitor C 1 is connected to power supply 12V, and the negative pole of capacitor C 1 is connected to an end of resistance R 2; The other end of resistance R 2 is connected to the base stage of negative pole and the triode Q3 of diode D3, the plus earth of diode D3, the grounded emitter of triode Q3, the collector electrode of triode Q3 and MCU control signal with.
See also shown in Figure 4ly, power-on pulse eliminating circuit of the present invention links to each other with screen T-CON plate power-supplying circuit.Wherein, the power supply of pulse eliminating circuit is adopted same 12V power supply with screen T-CON plate power-supplying circuit, and the capacitor C 1 of pulse eliminating circuit is connected to the 12V power supply jointly with diode D1, the inductance L 1 of screen T-CON plate power-supplying circuit.The triode Q3 collector electrode of pulse eliminating circuit connects the resistance R 3 of screen T-CON plate power-supplying circuit, make pulse eliminating circuit output and control input end " BKLT_EN " signal that shields T-CON plate power-supplying circuit with.The moment of start, there is immediate current to flow through in the capacitor C 1, capacitor C 1 negative pole is sensed a potential pulse when being equivalent to the POWER rising, thereby this pulse voltage makes triode Q3 conducting by the base stage that resistance R 2 is added to triode Q3, compensated since during start moment MCU initialization port be high level and can not drag down the deficiency of " BKLT_EN ", thereby eliminated the power-on pulse of LVDS_POWER, solve start flower screen or do not had the problem that thing shows, and after the supply power voltage POWER of circuit stablizes, no longer including electric current in the capacitor C 1 flows through, also no longer including electric current among the triode Q3 flows through, the triode C utmost point is ground connection no longer just, screen T-CON plate power-supplying circuit operate as normal.
See also shown in Figure 5, during start, 12V rises, mainboard MCU is in init state simultaneously, this moment, " BKLT_EN " signal of MCU output was a high level, and meanwhile pulse eliminating circuit was started working in the moment that 12V rises, there is electric current to flow through the base stage of triode Q3, triode Q3 conducting, the collector potential of triode Q3 is dragged down because output " BKLT_EN " signal of the collector electrode of triode Q3 and MCU with, so the base stage of triode Q2 is always low level, metal-oxide-semiconductor Q1 ends during this period, has not also just had the pulse of start moment to occur." BKLT_EN " signal can be dragged down after finishing Deng the MCU initialization, pulse eliminating circuit triode Q3 base stage no longer includes electric current and flows through, triode Q3 just ends, and the collector electrode of triode Q3 is high-impedance state over the ground, and is no longer influential to screen T-CON plate power-supplying circuit.
Most preferred embodiment described above only is that the present invention is set forth and illustrates, but is not limited to disclosed any concrete form, and it is possible carrying out many modifications and variations.
Claims (4)
1. a power-on pulse eliminating circuit includes power supply, it is characterized in that: the resistance R 2, diode D3 and the triode Q3 that also include capacitor C 1, be connected in series with capacitor C 1; Wherein, the positive pole of described capacitor C 1 is connected to power supply 12V, and the negative pole of capacitor C 1 is connected to an end of resistance R 2; The other end of resistance R 2 is connected to the base stage of negative pole and the triode Q3 of diode D3, the plus earth of diode D3, the grounded emitter of triode Q3, the collector electrode of triode Q3 and MCU control signal with.
2. power-on pulse eliminating circuit as claimed in claim 1, it is characterized in that: the power supply of pulse eliminating circuit is adopted same 12V power supply with screen T-CON plate power-supplying circuit, and the capacitor C 1 of pulse eliminating circuit is connected to the 12V power supply jointly with diode D1, the inductance L 1 of screen T-CON plate power-supplying circuit.
3. power-on pulse eliminating circuit as claimed in claim 2, it is characterized in that: the triode Q3 collector electrode of pulse eliminating circuit connects the resistance R 3 of screen T-CON plate power-supplying circuit, make pulse eliminating circuit output and control input end " BKLT_EN " signal that shields T-CON plate power-supplying circuit with.
4. power-on pulse eliminating circuit as claimed in claim 2 is characterized in that: described triode Q3 is a NPN type triode.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNA2008102166345A CN101388986A (en) | 2008-09-28 | 2008-09-28 | Power-on pulse eliminating circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNA2008102166345A CN101388986A (en) | 2008-09-28 | 2008-09-28 | Power-on pulse eliminating circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN101388986A true CN101388986A (en) | 2009-03-18 |
Family
ID=40478122
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNA2008102166345A Pending CN101388986A (en) | 2008-09-28 | 2008-09-28 | Power-on pulse eliminating circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN101388986A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101751902B (en) * | 2009-12-24 | 2011-12-14 | 北京时代民芯科技有限公司 | LVDS receiving circuit with adjustable resistor |
| CN102931964A (en) * | 2012-11-06 | 2013-02-13 | 上海摩软通讯技术有限公司 | Starting-up control circuit |
-
2008
- 2008-09-28 CN CNA2008102166345A patent/CN101388986A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101751902B (en) * | 2009-12-24 | 2011-12-14 | 北京时代民芯科技有限公司 | LVDS receiving circuit with adjustable resistor |
| CN102931964A (en) * | 2012-11-06 | 2013-02-13 | 上海摩软通讯技术有限公司 | Starting-up control circuit |
| CN102931964B (en) * | 2012-11-06 | 2016-10-05 | 上海摩软通讯技术有限公司 | Start control circuit |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN104778933B (en) | power management circuit | |
| CN105448261A (en) | Liquid crystal display | |
| CN206922420U (en) | A kind of over-and under-voltage protection circuit | |
| CN103889118A (en) | OLED driving power device | |
| CN106782410B (en) | Liquid crystal display device and its driving method | |
| CN105045438A (en) | Touch display circuit, drive method thereof and display device | |
| CN104269148A (en) | Liquid crystal driving circuit, liquid crystal driving method and liquid crystal display device | |
| CN101174072A (en) | Liquid crystal display | |
| CN106847215B (en) | Display device | |
| CN102770898B (en) | Source driver circuit of liquid crystal display device | |
| CN215770465U (en) | Display driving circuit and display device | |
| CN109767743A (en) | Driving circuit and its display device | |
| CN210325161U (en) | Hot plug detection circuit and display device | |
| CN106652931B (en) | Display driver circuit, drive control method, voltage supply chip and display equipment | |
| CN101388986A (en) | Power-on pulse eliminating circuit | |
| CN102810301A (en) | Liquid crystal display and method for controlling polarity inversion of pixel voltage of liquid crystal display | |
| CN209993327U (en) | Shutdown control circuit and display device thereof | |
| CN106898302B (en) | Pixel circuit control unit, driving method, pixel circuit and display device | |
| CN108550352B (en) | Grid voltage control circuit, grid driving circuit and display device | |
| CN101751881B (en) | Liquid crystal display device of external image signal source | |
| CN114724525B (en) | Display device, panel driving circuit thereof and charge discharging method | |
| CN102262860A (en) | Liquid crystal display and backlight driving device thereof | |
| CN202502724U (en) | Circuit having both liquid crystal display backlight pulse width modulation dimming function and direct-current voltage dimming function | |
| CN112349249B (en) | OLED driving power supply and OLED television | |
| CN112130701B (en) | Display touch device and power supply control method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C12 | Rejection of a patent application after its publication | ||
| RJ01 | Rejection of invention patent application after publication |
Open date: 20090318 |