CN101211030A - Electric power circuit - Google Patents

Electric power circuit Download PDF

Info

Publication number
CN101211030A
CN101211030A CNA2006100645859A CN200610064585A CN101211030A CN 101211030 A CN101211030 A CN 101211030A CN A2006100645859 A CNA2006100645859 A CN A2006100645859A CN 200610064585 A CN200610064585 A CN 200610064585A CN 101211030 A CN101211030 A CN 101211030A
Authority
CN
China
Prior art keywords
circuit
power circuit
display controller
pulse width
effect transistor
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.)
Granted
Application number
CNA2006100645859A
Other languages
Chinese (zh)
Other versions
CN100529858C (en
Inventor
刘汉涛
周通
肖华
乐昆
鲁建辉
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Innolux Shenzhen Co Ltd
Innolux Corp
Original Assignee
Innolux Shenzhen Co Ltd
Innolux Display Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Innolux Shenzhen Co Ltd, Innolux Display Corp filed Critical Innolux Shenzhen Co Ltd
Priority to CNB2006100645859A priority Critical patent/CN100529858C/en
Publication of CN101211030A publication Critical patent/CN101211030A/en
Application granted granted Critical
Publication of CN100529858C publication Critical patent/CN100529858C/en
Expired - Fee Related legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Landscapes

  • Liquid Crystal Display Device Control (AREA)

Abstract

The invention relates to a power supply circuit which consists of a display controller, a pulsewidth control circuit, a soft start capacitance, and a field effect transistor. The display controller includes an output end, and the pulsewidth control circuit includes an input end. The grid of the field effect transistor is in electric connection with the output end of the display controller, the source thereof is earthed, the drain thereof is earthed through the soft start capacitance, and the input end of the pulsewidth control circuit is in electric connection with the drain of the field effect transistor. The power supply circuit has the advantages of simplified circuit structure and decreased noise interference.

Description

Power circuit
Technical field
The present invention relates to a kind of power circuit.
Background technology
Electronic product such as LCD, LCD TV is controlled the work of its power circuit usually with pulse width adjusting circuit.But, this power circuit can produce the phenomenon of dash current or output voltage overshoot connecting and turn-off transient, is easy to this pulse width adjusting circuit and some other electronic components are caused damage, therefore, the power circuit of liquid crystal indicator is necessary to provide soft start function.
Seeing also Fig. 1, is a kind of synoptic diagram of prior art power circuit.This power circuit 10 comprises a first input end 101, one second input end 102, a display controller (Scaler Integrated Circuit) 11, one filter capacitor 12, a SS (soft start) control circuit 13, a pulse width adjustment (Pulse Width Modulation, PWM) circuit 15, an inverter (Inverter) 17 and a soft start capacitor 19.
This display controller 11 comprises an input end 111 and an output terminal 113, and this input end 111 is electrically connected the first input end 101 of this power circuit 10, and this output terminal 113 is by these filter capacitor 12 ground connection.This display controller 11 can be integrated circuit GM5621.
This SS (soft start) control circuit 13 comprises one first bipolar transistor 131, one second bipolar transistor 133, one first biasing resistor 135, one second biasing resistor 137 and one the 3rd biasing resistor 139.These first bipolar transistor, 131 base stages are electrically connected the output terminal 113 of this display controller 11 by this first biasing resistor 135, these first bipolar transistor, 131 base stages are simultaneously by these second biasing resistor, 137 ground connection, these first bipolar transistor, 131 grounded emitters, its collector is electrically connected this second input end 102 by the 3rd biasing resistor 139.These second bipolar transistor, 133 base stages are electrically connected this first bipolar transistor, 131 collectors, these second bipolar transistor, 133 grounded emitters, and its collector is by these soft start capacitor 19 ground connection.
This pulse width adjusting circuit 15 comprises an input end 151 and an output terminal 153, and this input end 151 is electrically connected these second bipolar transistor, 133 collectors, and its output terminal 153 is electrically connected this inverter 17.This pulse width adjusting circuit 15 can be integrated circuit (IC) 805.
This second input end 102 loads a positive 5V DC voltage, and this positive 5V DC voltage provides a base bias voltage for these second bipolar transistor, 133 base stages by the 3rd biasing resistor 139.When starting working by this display controller 11 of a software setting, this output terminal 113 outputs one 3.3V high level, when this display controller 11 quits work, this output terminal 113 outputs one 0V low level.
When the user presses the power switch of liquid crystal indicator, when opening this liquid crystal indicator, this power switch produces a power supply and opens signal, and is loaded on this first input end 101.The input end 111 of this display controller 11 receives starts working after this power supply is opened signal, this output terminal 113 outputs one 3.3V high level, this 3.3V high level is loaded on this first bipolar transistor, 131 base stages by this first biasing resistor 135, these first bipolar transistor, 131 conductings, these second bipolar transistor, 133 base stages become low level, this second bipolar transistor 133 ends, and its current collection is high-impedance state very.The internal current source of this pulse width adjusting circuit 15 is to these soft start capacitor 19 chargings, and its duration of charging is about 450us by measurement.When these soft start capacitor 19 charging voltages are higher than triggering level (this triggering level is 2V), this pulse width adjusting circuit 15 is started working, and drives this control inverter backlight 17 to light the backlight of this liquid crystal indicator.
When the user presses the power switch of this liquid crystal indicator, when closing this liquid crystal indicator, this power switch produces a power supply and closes signal, and is loaded on this first input end 101.The input end 111 of this display controller 11 receives and quits work after this power supply closes signal, this output terminal 113 outputs one 0V low level, these first bipolar transistor, 131 base stages become low level, this first bipolar transistor 131 ends, these second bipolar transistor, 133 base stages are high level by drawing on this positive 5V DC voltage, these second bipolar transistor, 133 conductings, these second bipolar transistor, 133 collectors become low level, this soft start capacitor 19 is by the collector of this second bipolar transistor 133, the emitter discharge, input end 151 voltages of this pulse width adjusting circuit 15 slowly descend and stop to send control signals to this inverter 17 up to this pulse width adjusting circuit 15, this control inverter 17 backlight quits work, and the backlight of this liquid crystal indicator closed.
But, the conducting of this first, second bipolar transistor 131,133 of SS (soft start) control circuit 13 usefulness of this power circuit 10 with end the charge and discharge of controlling this soft start capacitor 19, the electronic component number of this SS (soft start) control circuit 13 is more, the circuit structure more complicated, printed circuit board (PCB) (Printed Circuit Board, PCB) Bu Xian complexity have been increased.And since this first, second bipolar transistor the 131, the 133rd, current controling element, need provide extra positive 5V direct supply to keep its operate as normal as bias voltage, the existence of positive 5V direct current supply line also produces noise to the electronic component around it in this printed circuit board (PCB), influences the stability of this power circuit.
Summary of the invention
In order to solve circuit construction of electric power complexity in the prior art, problem that noise is big, the invention provides a kind of power circuit of simplifying circuit structure, reducing noise.
A kind of power circuit, it comprises a display controller, a pulse width adjusting circuit, a soft start capacitor, this display controller comprises an output terminal, this pulse width adjusting circuit comprises an input end, and this pulse width adjusting circuit input end is by this soft start capacitor ground connection, wherein, this power circuit also comprises a field-effect transistor, this field-effect transistor grid is electrically connected this display controller output terminal, its source ground, and its drain electrode is electrically connected this pulse width adjusting circuit input end.
Compared with prior art, power circuit of the present invention with this field-effect transistor by controlling the charge and discharge of this soft start capacitor with conducting, compare with the SS (soft start) control circuit that two bipolar transistors and three biasing resistors constitute with the power circuit of prior art, reduced the number of electronic component, simplified circuit structure, the wiring of the printed circuit board (PCB) of this power circuit is more prone to.And because this field-effect transistor is to control drain electrode and source electrode by the height of grid voltage, do not need extra power supply to provide operating voltage for this field-effect transistor, therefore do not need extra power lead to be connected to this field-effect transistor in this printed circuit board (PCB), thereby reduced the noise of this power circuit, helped the raising of this power circuit performance.This power circuit is than the power circuit electronic component decreased number of prior art simultaneously, and power consumption reduces.
Description of drawings
Fig. 1 is a kind of synoptic diagram of prior art power circuit.
Fig. 2 is the synoptic diagram of power circuit of the present invention.
Embodiment
Seeing also Fig. 2, is the synoptic diagram of power circuit of the present invention.This power circuit 20 comprises an input end 201, a display controller 21, a filter capacitor 22, a field-effect transistor 23, a pulse width adjusting circuit 25, an inverter 27 and a soft start capacitor 29.This display controller 21 comprises an input end 211 and an output terminal 213, and this display controller 21 can be integrated circuit GM5621.This pulse width adjusting circuit 25 comprises an input end 251 and an output terminal 253.This pulse width adjusting circuit 25 can be integrated circuit (IC) 805.This field-effect transistor 23 is a N channel enhancement MOS field-effect transistor, and its model is RK7002.
This input end 201 is electrically connected the input end 211 of this display controller 21, and the output terminal 213 of this display controller 21 is by these filter capacitor 22 ground connection.
These field-effect transistor 23 grids are electrically connected this display controller 21 output terminals 213, its source ground, and its drain electrode is by these soft start capacitor 29 ground connection.
These pulse width adjusting circuit 25 input ends 251 are electrically connected this field-effect transistor 23 drain electrodes, and its output terminal 253 is electrically connected this inverter 27.
When starting working, this output terminal 213 is exported a 0V low level by this display controller 21 of a software setting, and this display controller 21 is when quitting work, and this output terminal 213 is exported a 3.3V high level.
When the user presses the power switch of liquid crystal indicator, when opening this liquid crystal indicator, this power switch produces a power supply and opens signal, and is loaded on this input end 201.The input end 211 of this display controller 21 receives starts working after this power supply is opened signal, its output terminal 213 outputs one 0V low level, these field-effect transistor 23 grids become low level, this field-effect transistor 23 ends, its drain electrode is high-impedance state, the internal current source of this pulse width adjusting circuit 25 is to these soft start capacitor 29 chargings, and its duration of charging is about 450us by measurement.When these soft start capacitor 29 charging voltages are higher than triggering level (this triggering level is 2V), this pulse width adjusting circuit 25 is started working, and drives this control inverter backlight 27 to light the backlight of this liquid crystal indicator.
When the user presses the power switch of this liquid crystal indicator, when closing this liquid crystal indicator, this power switch produces a power supply and closes signal, and is loaded on this input end 201.The input end 211 of this display controller 21 receives and quits work after this power supply closes signal, its output terminal 213 outputs one 3.3V high level, these field-effect transistor 23 grids become high level, these field-effect transistor 23 conductings, its drain electrode becomes low level, promptly the input end 251 of this pulse width adjusting circuit 25 is a low level, this soft start capacitor 29 is by the drain electrode of this field-effect transistor 23, the source electrode discharge, input end 251 voltages of this pulse width adjusting circuit 25 slowly descend and stop to send control signals to this inverter 27 up to this pulse width adjusting circuit 25, this control inverter 27 backlight quits work, and the backlight of this liquid crystal indicator closed.
Compared with prior art, the charge and discharge of this soft start capacitor 29 is controlled in end and the conducting of this field-effect transistor 23 of power circuit 20 usefulness of the present invention, compare with the SS (soft start) control circuit that prior art power circuit 10 usefulness, two bipolar transistors and three biasing resistors constitute, reduced the number of electronic component, simplified circuit structure, the wiring of the printed circuit board (PCB) of this power circuit 20 is more prone to.And because this field-effect transistor 23 is to control drain electrode and source electrode by the height of grid voltage, do not need extra power supply to provide operating voltage for this field-effect transistor 23, therefore do not need extra power lead to be connected to this field-effect transistor 23 in this printed circuit board (PCB), thereby reduced the noise of this power circuit 20, helped the raising of these power circuit 20 stabilities.This power circuit 20 is than the power circuit 10 electronic component decreased number of prior art simultaneously, and its power consumption reduces.

Claims (7)

1. power circuit, it comprises a display controller, a pulse width adjusting circuit, a soft start capacitor, this display controller comprises an output terminal, this pulse width adjusting circuit comprises an input end, this pulse width adjusting circuit input end is by this soft start capacitor ground connection, it is characterized in that: this power circuit also comprises a field-effect transistor, this field-effect transistor grid is electrically connected this display controller output terminal, its source ground, its drain electrode is electrically connected this pulse width adjusting circuit input end.
2. power circuit as claimed in claim 1 is characterized in that: this power circuit also comprises control liquid crystal indicator inverter backlight, and this pulse width adjusting circuit drives this inverter to light or to close the backlight of this liquid crystal indicator.
3. power circuit as claimed in claim 2 is characterized in that: when this display controller is started working, and output 0V low level; When quitting work, output 3.3V high level.
4. power circuit as claimed in claim 1 is characterized in that: this field-effect transistor N channel enhancement MOS field-effect transistor.
5. power circuit as claimed in claim 4 is characterized in that: this field-effect transistor model is RK7002.
6. power circuit as claimed in claim 1 is characterized in that: this display controller is integrated circuit GM5621.
7. power circuit as claimed in claim 1 is characterized in that: this pulse width adjusting circuit is an integrated circuit (IC) 805.
CNB2006100645859A 2006-12-29 2006-12-29 Electric power circuit Expired - Fee Related CN100529858C (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CNB2006100645859A CN100529858C (en) 2006-12-29 2006-12-29 Electric power circuit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CNB2006100645859A CN100529858C (en) 2006-12-29 2006-12-29 Electric power circuit

Publications (2)

Publication Number Publication Date
CN101211030A true CN101211030A (en) 2008-07-02
CN100529858C CN100529858C (en) 2009-08-19

Family

ID=39611168

Family Applications (1)

Application Number Title Priority Date Filing Date
CNB2006100645859A Expired - Fee Related CN100529858C (en) 2006-12-29 2006-12-29 Electric power circuit

Country Status (1)

Country Link
CN (1) CN100529858C (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103051232A (en) * 2012-12-07 2013-04-17 京东方科技集团股份有限公司 Inverter and display device
CN103295538A (en) * 2013-07-02 2013-09-11 深圳市华星光电技术有限公司 Backlight drive circuit and method for shortening soft starting time of backlight drive circuit
CN110910848A (en) * 2019-11-28 2020-03-24 Tcl华星光电技术有限公司 Driving circuit and driving method of liquid crystal display
CN117031346A (en) * 2023-07-28 2023-11-10 深圳凌扬微电子有限公司 Quick test circuit and device for power supply equipment

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103051232A (en) * 2012-12-07 2013-04-17 京东方科技集团股份有限公司 Inverter and display device
CN103051232B (en) * 2012-12-07 2015-10-21 京东方科技集团股份有限公司 A kind of inverter and display unit
CN103295538A (en) * 2013-07-02 2013-09-11 深圳市华星光电技术有限公司 Backlight drive circuit and method for shortening soft starting time of backlight drive circuit
CN103295538B (en) * 2013-07-02 2015-03-04 深圳市华星光电技术有限公司 Backlight drive circuit and method for shortening soft starting time of backlight drive circuit
CN110910848A (en) * 2019-11-28 2020-03-24 Tcl华星光电技术有限公司 Driving circuit and driving method of liquid crystal display
US11289040B2 (en) 2019-11-28 2022-03-29 Tcl China Star Optoelectronics Technology Co., Ltd. Driving circuit and driving method of liquid crystal display
CN117031346A (en) * 2023-07-28 2023-11-10 深圳凌扬微电子有限公司 Quick test circuit and device for power supply equipment

Also Published As

Publication number Publication date
CN100529858C (en) 2009-08-19

Similar Documents

Publication Publication Date Title
US7936189B2 (en) Driver circuit and method for reducing electromagnetic interference
CN1953030B (en) Control circuit device and liquid crystal display with the same
CN104866000B (en) Gate driving circuit and method with voltage-stablizer
KR20060090718A (en) Bootstrap diode emulator with dynamic back-gate biasing
US8760200B2 (en) Gate driving apparatus
CN100529858C (en) Electric power circuit
CN100529854C (en) Power supply circuit and LCD using the same
CN100592374C (en) Liquid crystal display device and power supply sequencing control circuit thereof
CN106329959A (en) High-voltage self-powered circuit
CN107040738A (en) Eliminate voltage and current exceeded circuit when semiotic function module starts upper electricity
CN101458901B (en) Power supply circuit for LCD
CN102035381B (en) BOOST circuit with adjusting starting voltage
EP3651334A1 (en) Power supply drive module, power supply device and electronic cigarette
CN200965775Y (en) Voltage rising waveform controllable circuit and LCD TV
CN103488267A (en) Power control circuit
CN1848023A (en) Control circuit for the control signal of clock generator
TW200828247A (en) Power supply circuit
CN101719724B (en) Quasi-level-switching device of multi-quasi-level power supply converter
CN103684369A (en) Active clamp for semiconductor switch
CN100529851C (en) Liquid crystal display device power supply and discharge circuit
CN208521588U (en) A kind of liquid crystal display power supply circuit and electronic device
CN219204473U (en) Novel low-cost high-voltage driver circuit
CN218997931U (en) Quick power-on and power-off circuit
CN218416177U (en) Drive circuit and test circuit
CN109494986B (en) Direct current voltage reduction circuit and direct current voltage reduction 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
C14 Grant of patent or utility model
GR01 Patent grant
CF01 Termination of patent right due to non-payment of annual fee

Granted publication date: 20090819

Termination date: 20191229

CF01 Termination of patent right due to non-payment of annual fee