CN206894500U - A kind of voltage conversion circuit, power supply circuit and LCD TV - Google Patents
A kind of voltage conversion circuit, power supply circuit and LCD TV Download PDFInfo
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- CN206894500U CN206894500U CN201720859958.5U CN201720859958U CN206894500U CN 206894500 U CN206894500 U CN 206894500U CN 201720859958 U CN201720859958 U CN 201720859958U CN 206894500 U CN206894500 U CN 206894500U
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Abstract
The utility model discloses a kind of voltage conversion circuit, power supply circuit and LCD TV, the voltage conversion circuit has voltage input end and voltage output end；The voltage conversion circuit includes DC/DC modules and voltage-regulator diode；The input of the DC/DC modules is connected with the voltage input end, and the output end of the DC/DC modules is connected with the voltage output end；The negative pole of the voltage-regulator diode is connected with the voltage input end, and the positive pole of the voltage-regulator diode is connected with the Enable Pin of the DC/DC modules；The breakdown reverse voltage of the voltage-regulator diode is more than first threshold and is less than Second Threshold, the first threshold and Second Threshold are determined according to the enabled threshold voltage of the maximum power down bounce voltage of the voltage input end, normal working voltage and the DC/DC modules, so that it is determined that the breakdown reverse voltage.The voltage conversion circuit can effectively prevent power down rebound phenomena, ensure the normal work of the voltage conversion circuit and subordinate's circuit.
Description
Technical field
It the utility model is related to electronic circuit field, and in particular to a kind of voltage conversion circuit, power supply circuit and liquid crystal electricity
Depending on.
Background technology
Be electrically cut off outside or undervoltage condition under, easily there is voltage bounce phenomenon in the input voltage of voltage conversion circuit, makes
Have much into the reason for voltage bounce phenomenon, such as when circuit includes flyback sourse and voltage conversion circuit, strike back power supply
In primary current controller hiccup, cause the output voltage of flyback sourse to rebound, so that the input of voltage conversion circuit
Voltage has a rebound.After ac-input power supply is pulled out, now the output voltage of flyback sourse has a fixed load so that flyback inputs
Storage capacitor voltage declines, and causes primary side current of transformer excessive, triggers overcurrent protection, and primary side turns off, and output voltage is rapid
Decline.After transformer primary side shut-off, primary current 0, but now input storage capacitor also has voltage so that and primary side PWM is controlled
Device is started working again, and now the output voltage of flyback sourse rises again, and flyback sourse will repeat this process, until flyback inputs
Untill storage capacitor voltage can not make PWM controller work.
The power down bounce-back of the input of voltage conversion circuit can cause rear class system reboot, and bad experience is caused to user.
In addition, when reading Flash chip (being used for storage system program) after rear class system reboot, instant power-down may damage Flash
Chip.
Utility model content
The purpose of this utility model is to provide a kind of voltage conversion circuit, power supply circuit and LCD TV, can effectively prevent
The power down rebound phenomena of voltage conversion circuit.
To solve above technical problem, the utility model embodiment provides a kind of voltage conversion circuit, the voltage conversion
Circuit has voltage input end and voltage output end；The voltage conversion circuit includes DC/DC modules and voltage-regulator diode；
The input of the DC/DC modules is connected with the voltage input end, the output end of the DC/DC modules with it is described
Voltage output end connects；
The negative pole of the voltage-regulator diode is connected with the voltage input end, the positive pole of the voltage-regulator diode with it is described
The Enable Pin connection of DC/DC modules；
The breakdown reverse voltage of the voltage-regulator diode is more than first threshold and is less than Second Threshold；Wherein, described first
Threshold value is equal to the maximum power down bounce voltage of the voltage input end and the difference of the enabled threshold voltage of the DC/DC modules；
The Second Threshold is equal to the normal working voltage of the voltage input end and the difference of the enabled threshold voltage of the DC/DC modules
Value.
Preferably, the voltage conversion circuit also includes resistance, the first end of the resistance and the voltage-regulator diode
Positive pole connects, the second end ground connection of the resistance.
Preferably, the voltage conversion circuit also includes electric capacity, the first end of the electric capacity and the voltage-regulator diode
Positive pole connects, the second end ground connection of the electric capacity.
The utility model embodiment also provides a kind of power supply circuit, including AC/DC modules, switch power module and above-mentioned
Voltage conversion circuit, the input of the AC/DC modules are used to be connected with feeder ear, the output end of the AC/DC modules and institute
The input connection of switch power module is stated, the output end of the switch power module and the voltage of the voltage conversion circuit are defeated
Enter end connection, the voltage output end of the voltage conversion circuit is used to be connected with the power end of load.
The utility model embodiment also provides a kind of LCD TV, including AC/DC modules, switch power module, TV master
Plate and above-mentioned voltage conversion circuit, the input of the AC/DC modules are used to be connected with feeder ear, the AC/DC modules
Output end is connected with the input of the switch power module, the output end of the switch power module and voltage conversion electricity
The voltage input end connection on road, the voltage output end of the voltage conversion circuit are connected with the power end of the TV motherboard.
Preferably, the LCD TV also includes LCD MODULE, the backlight electric power end of the LCD MODULE with
The output end connection of the switch power module.
Preferably, the output end of the switch power module includes the first output end and the second output end；Described first is defeated
Go out end to be connected with the voltage input end of the voltage conversion circuit；Second output end and the backlight of the LCD MODULE
Power end connects.
Preferably, the LCD TV also includes voltage reduction module and motherboard flash chip, the input of the voltage reduction module
It is connected with the voltage output end of the voltage conversion circuit, the output end of the voltage reduction module and the motherboard flash chip
Power end connects.
Preferably, the switch power module is flyback sourse.
Preferably, the voltage reduction module is low-pressure linear voltage-stablizer.
Compared to prior art, a kind of beneficial effect of voltage conversion circuit provided by the utility model is：Described
Connected between the Enable Pin of voltage input end and the DC/DC modules voltage-regulator diode, wherein the voltage-regulator diode
Negative pole is connected with the input, and the positive pole of the voltage-regulator diode is connected with the Enable Pin of the DC/DC modules, according to described
The enabled threshold voltage of maximum power down bounce voltage, the normal working voltage and the DC/DC modules determines the voltage stabilizing two
The breakdown reverse voltage of pole pipe, so as to choose suitable voltage-regulator diode, voltage when can effectively prevent higher level's circuit power down
There is power down rebound phenomena in change-over circuit, while when ensureing upper electric, the normal work of the DC/DC modules.Meanwhile this practicality is new
Type also proposes a kind of power supply circuit and LCD TV including above-mentioned voltage conversion circuit.
Brief description of the drawings
Fig. 1 is a kind of circuit diagram for voltage conversion circuit that the utility model embodiment provides；
Fig. 2 is a kind of block diagram for LCD TV that the utility model embodiment provides.
Embodiment
Below in conjunction with the accompanying drawing in the utility model embodiment, the technical scheme in the embodiment of the utility model is carried out
Clearly and completely describing, it is clear that described embodiment is only the utility model part of the embodiment, rather than whole
Embodiment.Based on the embodiment in the utility model, those of ordinary skill in the art are not under the premise of creative work is made
The every other embodiment obtained, belong to the scope of the utility model protection.
Referring to Fig. 1, it is a kind of circuit diagram for voltage conversion circuit that the embodiment of the utility model one is provided, it is described
Voltage conversion circuit has voltage input end Vin and voltage output end Vout；The voltage conversion circuit include DC/DC modules with
Voltage-regulator diode D；
The input Vi of the DC/DC modules is connected with the voltage input end Vin, the output end of the DC/DC modules
Vo is connected with the voltage output end Vout；
The negative pole of the voltage-regulator diode D is connected with the voltage input end Vin, the positive pole of the voltage-regulator diode D with
The Enable Pin En connections of the DC/DC modules；
The breakdown reverse voltage V of the voltage-regulator diode DDMore than first threshold and it is less than Second Threshold；Wherein, described
One threshold value is equal to the maximum power down bounce voltage V of the voltage input end VinaWith the enabled threshold voltage of the DC/DC modules
VthDifference；The Second Threshold is equal to the normal working voltage V of the voltage input end VinnWith making for the DC/DC modules
Can threshold voltage VthDifference.The enabled threshold voltage V of the DC/DC modulesthRefer to that the DC/DC modules can be being driven just
The minimum voltage often to work.
According to the maximum power down bounce voltage Va, the normal working voltage VnWith the enabled threshold value of the DC/DC modules
Voltage VthDetermine the breakdown reverse voltage V of the voltage-regulator diodeD, so as to choose suitable voltage-regulator diode.
In the state of normal work, the normal working voltage V of the voltage input end VinnIt is input to the voltage stabilizing two
Pole pipe D, the voltage-regulator diode D is breakdown, now, the voltage V of the Enable Pin Enen=Vn-VD, and Ven>VthSo that it is described
DC/DC module normal works, voltage conversion will be carried out.In the state of higher level's circuit power down, the voltage input end Vin is most
Big power down bounce voltage VaThe voltage-regulator diode D is input to, the voltage-regulator diode D is breakdown, now, the Enable Pin
Voltage Ven=Va-VD, and Ven<VthSo that the DC/DC modules do not work, without voltage conversion.It is suitable steady by choosing
Press the breakdown reverse voltage V of diodeDIt can effectively prevent that the power down that the voltage conversion circuit occurs during higher level's circuit power down is anti-
When playing phenomenon, while ensureing upper electric, the normal work of the DC/DC modules.
In a kind of optional embodiment, the voltage conversion circuit also includes resistance R, the first end of the resistance R
It is connected with the positive pole of the voltage-regulator diode D, the second end ground connection of the resistance R.The resistance R is used to protect the voltage stabilizing two
Pole pipe, prevent the voltage-regulator diode electric current is excessive from causing to damage.
In a kind of optional embodiment, the voltage conversion circuit also includes electric capacity C, the first end of the electric capacity C
It is connected with the positive pole of the voltage-regulator diode D, the second end ground connection of the electric capacity C.The electric capacity C is used to filter, and eliminates spike
Interference so that the voltage for being input to the Enable Pin En is smooth.
The voltage conversion circuit can effectively prevent power down rebound phenomena, ensure the voltage conversion circuit and subordinate's electricity
The normal work on road, at the same it is simple in construction, cost is low, be easy to market apply and promote.
A kind of power supply circuit that the embodiment of the utility model one also provides, the power supply circuit include AC/DC modules, switch
Power module and above-mentioned voltage conversion circuit, the input of the AC/DC modules are used to be connected with feeder ear, the AC/DC
The output end of module is connected with the input of the switch power module, the output end of the switch power module and the voltage
The voltage input end connection of change-over circuit, the voltage output end of the voltage conversion circuit are used to be connected with the power end of load.
Referring to Fig. 2, it is that the embodiment of the utility model one provides a kind of block diagram of LCD TV, the LCD TV bag
Include AC/DC modules 1, switch power module 2, TV motherboard 3 and above-mentioned voltage conversion circuit 4, the AC/DC modules 1 it is defeated
Enter end to be used to be connected with feeder ear, the output end of the AC/DC modules 1 is connected with the input of the switch power module 2, institute
The output end for stating switch power module 2 is connected with the voltage input end of the voltage conversion circuit 4, the voltage conversion circuit 4
Voltage output end be connected with the power end of the TV motherboard 3.
In a kind of optional embodiment, the LCD TV also includes LCD MODULE 5, the liquid crystal display mode
The backlight electric power end of block 5 is connected with the output end of the switch power module 2.
In a kind of optional embodiment, the output end of the switch power module 2 includes the first output end and second
Output end；First output end is connected with the voltage input end of the voltage conversion circuit 4；Second output end with it is described
The backlight electric power end connection of LCD MODULE 5.
In a kind of optional embodiment, the LCD TV also includes voltage reduction module and motherboard flash chip, described
The input of voltage reduction module is connected with the output end of the voltage conversion circuit, the output end of the voltage reduction module and the mainboard
The power end connection of Flash chip.
In a kind of optional embodiment, the switch power module is flyback sourse.
In a kind of optional embodiment, the voltage reduction module is low-pressure linear voltage-stablizer.
The power supply plan of the LCD TV is that 220V civil powers pass through the rectification of AC/DC modules 1 and the Switching Power Supply
After the processing of module 2,220V AC voltage is converted into the 12V DC voltage of the LCD TV main power source, the Switching Power Supply
Module 2 exports two-way voltage, is used to power to the LCD MODULE 5 all the way, another way is used to export to the DC/DC moulds
Block 4, by the DC/DC modules 4 by the 12V DC voltage conversion into 5V DC voltages, the 5V DC voltages are used to give
The TV motherboard 3 is powered, and the 5V DC voltages are converted into 3.3V DC voltages, the 3.3V by the voltage reduction module
DC voltage is used to power to the motherboard flash chip.It is described after the AC input end power supply of the AC/DC modules is pulled out
The output end of switch power module produces bounce voltage, and still, the bounce voltage is input in the voltage conversion circuit 4
The Enable Pin of the DC/DC modules is output to after voltage-regulator diode again, now the enabled terminal voltage of the DC/DC modules is less than institute
The enabled threshold voltage of DC/DC modules is stated, the DC/DC modules will not be driven to work, so that the DC/DC modules is defeated
It is not in power down rebound phenomena to go out end, so effectively prevent the TV motherboard because power down rebound phenomena causes system weight
Open, meanwhile, protect the device on mainboard against damages, such as motherboard flash chip.
Compared to prior art, a kind of beneficial effect for voltage conversion circuit that the utility model embodiment provides is：
Connected between the Enable Pin of the voltage input end and the DC/DC modules voltage-regulator diode, wherein the voltage stabilizing two
The negative pole of pole pipe is connected with the input, and the positive pole of the voltage-regulator diode is connected with the Enable Pin of the DC/DC modules, root
According to described in the enabled threshold voltage determination of the maximum power down bounce voltage, the normal working voltage and the DC/DC modules
The breakdown reverse voltage of voltage-regulator diode, so as to choose suitable voltage-regulator diode, it can effectively prevent higher level's circuit power down when institute
When stating voltage conversion circuit and power down rebound phenomena occur, while ensureing upper electric, the normal work of the DC/DC modules.Meanwhile this
Utility model also proposes a kind of power supply circuit and LCD TV including above-mentioned voltage conversion circuit.
Above is preferred embodiment of the present utility model, it is noted that for those skilled in the art
For, on the premise of the utility model principle is not departed from, some improvements and modifications can also be made, these improvements and modifications
It is considered as the scope of protection of the utility model.
Claims (10)
1. a kind of voltage conversion circuit, it is characterised in that the voltage conversion circuit has voltage input end and voltage output end；
The voltage conversion circuit includes DC/DC modules and voltage-regulator diode；
The input of the DC/DC modules is connected with the voltage input end, output end and the voltage of the DC/DC modules
Output end connects；
The negative pole of the voltage-regulator diode is connected with the voltage input end, the positive pole of the voltage-regulator diode and the DC/DC
The Enable Pin connection of module；
The breakdown reverse voltage of the voltage-regulator diode is more than first threshold and is less than Second Threshold；Wherein, the first threshold
Equal to the maximum power down bounce voltage and the difference of the enabled threshold voltage of the DC/DC modules of the voltage input end；It is described
Second Threshold is equal to the normal working voltage of the voltage input end and the difference of the enabled threshold voltage of the DC/DC modules.
2. voltage conversion circuit as claimed in claim 1, it is characterised in that the voltage conversion circuit also includes resistance, institute
The first end for stating resistance is connected with the positive pole of the voltage-regulator diode, the second end ground connection of the resistance.
3. voltage conversion circuit as claimed in claim 1 or 2, it is characterised in that the voltage conversion circuit also includes electric capacity,
The first end of the electric capacity is connected with the positive pole of the voltage-regulator diode, the second end ground connection of the electric capacity.
4. a kind of power supply circuit, it is characterised in that including AC/DC modules, switch power module and as claims 1 to 3 is any
Voltage conversion circuit described in, the inputs of the AC/DC modules are used to be connected with feeder ear, the AC/DC modules it is defeated
Go out end to be connected with the input of the switch power module, the output end of the Switching Power Supply and the electricity of the voltage conversion circuit
Input connection is pressed, the voltage output end of the voltage conversion circuit is used to be connected with the power end of load.
5. a kind of LCD TV, it is characterised in that including AC/DC modules, switch power module, TV motherboard and such as claim
Voltage conversion circuit described in 1~3 any one, the input of the AC/DC modules are used to be connected with feeder ear, the AC/DC
The output end of module is connected with the input of the switch power module, the output end of the switch power module and the voltage
The voltage input end connection of change-over circuit, the voltage output end of the voltage conversion circuit and the power end of the TV motherboard connect
Connect.
6. LCD TV as claimed in claim 5, it is characterised in that the LCD TV also includes LCD MODULE, institute
The backlight electric power end for stating LCD MODULE is connected with the output end of the switch power module.
7. LCD TV as claimed in claim 6, it is characterised in that it is defeated that the output end of the switch power module includes first
Go out end and the second output end；First output end is connected with the voltage input end of the voltage conversion circuit；Described second is defeated
Go out end to be connected with the backlight electric power end of the LCD MODULE.
8. LCD TV as claimed in claim 5, it is characterised in that the LCD TV also includes voltage reduction module and mainboard
Flash chip, the input of the voltage reduction module are connected with the voltage output end of the voltage conversion circuit, the voltage reduction module
Output end be connected with the power end of the motherboard flash chip.
9. the LCD TV as described in claim 5 or 6, it is characterised in that the switch power module is flyback sourse.
10. LCD TV as claimed in claim 8, it is characterised in that the voltage reduction module is low-pressure linear voltage-stablizer.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201720859958.5U CN206894500U (en) | 2017-07-14 | 2017-07-14 | A kind of voltage conversion circuit, power supply circuit and LCD TV |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201720859958.5U CN206894500U (en) | 2017-07-14 | 2017-07-14 | A kind of voltage conversion circuit, power supply circuit and LCD TV |
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| Publication Number | Publication Date |
|---|---|
| CN206894500U true CN206894500U (en) | 2018-01-16 |
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| CN201720859958.5U Active CN206894500U (en) | 2017-07-14 | 2017-07-14 | A kind of voltage conversion circuit, power supply circuit and LCD TV |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109449914A (en) * | 2018-10-15 | 2019-03-08 | 青岛海信电器股份有限公司 | OLED display and its method of supplying power to |
| CN111048036A (en) * | 2018-10-15 | 2020-04-21 | 青岛海信电器股份有限公司 | OLED display device |
| WO2020077976A1 (en) * | 2018-10-15 | 2020-04-23 | 青岛海信电器股份有限公司 | Oled display device, oled television, and power supplying method therefor |
-
2017
- 2017-07-14 CN CN201720859958.5U patent/CN206894500U/en active Active
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109449914A (en) * | 2018-10-15 | 2019-03-08 | 青岛海信电器股份有限公司 | OLED display and its method of supplying power to |
| CN111048036A (en) * | 2018-10-15 | 2020-04-21 | 青岛海信电器股份有限公司 | OLED display device |
| WO2020077976A1 (en) * | 2018-10-15 | 2020-04-23 | 青岛海信电器股份有限公司 | Oled display device, oled television, and power supplying method therefor |
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Legal Events
| Date | Code | Title | Description |
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| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20190508 Address after: 510530 3/F 310, 192 Kezhu Road, Guangzhou High-tech Industrial Development Zone, Guangdong Province Patentee after: Guangzhou Kun Electronic Technology Co. Ltd. Address before: 510530 No. 6, Yun Po four road, Whampoa District, Guangzhou, Guangdong. Patentee before: Guangzhou CVT Electronics Technology Co., Ltd. |
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| TR01 | Transfer of patent right |