CN204030995U - A kind of Switching Power Supply start-up circuit - Google Patents
A kind of Switching Power Supply start-up circuit Download PDFInfo
- Publication number
- CN204030995U CN204030995U CN201420072289.3U CN201420072289U CN204030995U CN 204030995 U CN204030995 U CN 204030995U CN 201420072289 U CN201420072289 U CN 201420072289U CN 204030995 U CN204030995 U CN 204030995U
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- power supply
- circuit
- resistance
- input
- switching power
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Abstract
The utility model discloses a kind of Switching Power Supply start-up circuit, comprise input, output, switching tube and voltage stabilizing didoe, the positive pole of input termination switch power supply input rectification circuit output, export termination Switching Power Supply PWM driving chip, the negative electrode of voltage stabilizing didoe connects described input by the first resistance, and anode connects described output; The input described in first termination of switching tube, the second end of switching tube connects described output by the 3rd resistance; The control pole of switching tube connects the negative electrode of voltage stabilizing didoe.Starting current of the present utility model is substantially constant, and when the voltage of input changes, starting up's time can keep constant.
Description
[technical field]
The utility model relates to Switching Power Supply, particularly relates to a kind of Switching Power Supply start-up circuit.
[background technology]
Traditional Switching Power Supply start-up circuit is the resistance charging circuit of control chip, make Switching Power Supply at stand-by power consumption and starting up's time be difficult to accomplish balance, start-up time changes with the size of input voltage, be difficult to meet simultaneously input voltage lower time starting up's time shorter and input voltage is higher time the less requirement of stand-by power consumption.And after Switching Power Supply starts, the supply power voltage VCC of power supply chip is still in high voltage bus power supply state, and the whole loss of power increases, and efficiency is on the low side.
[summary of the invention]
The technical problems to be solved in the utility model is to provide a kind of start-up time not with the Switching Power Supply start-up circuit of input voltage change.
The technical problem that the utility model will solve further is to provide the Switching Power Supply start-up circuit that a kind of start-up time is shorter, stand-by power consumption is less.
In order to solve the problems of the technologies described above, the technical solution adopted in the utility model is, a kind of Switching Power Supply start-up circuit, comprise input, output, switching tube and voltage stabilizing didoe, the positive pole of input termination switch power supply input rectification circuit output, export termination Switching Power Supply PWM driving chip, the negative electrode of voltage stabilizing didoe connects described input by the first resistance, and anode connects described output; The input described in first termination of switching tube, the second end of switching tube connects described output by the 3rd resistance; The control pole of switching tube connects the negative electrode of voltage stabilizing didoe.
Above-described Switching Power Supply start-up circuit, comprises the second resistance, and the first end of switching tube connects described input by the second resistance.
Above-described Switching Power Supply start-up circuit, described switching tube is metal-oxide-semiconductor, and the grid of metal-oxide-semiconductor connects the negative electrode of voltage stabilizing didoe, and drain electrode connects described input, and source electrode connects described output by the 3rd resistance.
Above-described Switching Power Supply start-up circuit, comprises filter capacitor, and filter capacitor and voltage stabilizing didoe also connect.
Above-described Switching Power Supply start-up circuit, comprises breaking circuit, and breaking circuit comprises second switch pipe and bleeder circuit, and bleeder circuit is connected between described output and ground, and bleeder circuit comprises the 4th resistance and the 5th resistance of series connection; The negative electrode of the first termination voltage stabilizing didoe of second switch pipe, the second end ground connection; Tie point between control termination the 4th resistance of second switch pipe and the 5th resistance.
Above-described Switching Power Supply start-up circuit, comprises diode, and the anode of diode connects the anode of voltage stabilizing didoe, and negative electrode connects described output.
The starting current substantially constant of the utility model Switching Power Supply start-up circuit is constant, and when the voltage of input changes, starting up's time can remain unchanged.
[accompanying drawing explanation]
Below in conjunction with the drawings and specific embodiments, the utility model is described in further detail.
Fig. 1 is the circuit theory diagrams of the utility model embodiment Switching Power Supply.
Fig. 2 is the circuit theory diagrams of the utility model Switching Power Supply start-up circuit embodiment 1.
Fig. 3 is the circuit theory diagrams of the utility model Switching Power Supply start-up circuit embodiment 2.
Fig. 4 is the circuit theory diagrams of the utility model Switching Power Supply start-up circuit embodiment 3.
[embodiment]
The switching power circuit of the utility model embodiment flyback topologies structure as shown in Figure 1, comprises former limit circuit and secondary circuit, and former limit circuit and secondary circuit are coupled by transformer T, and start-up circuit comprises the circuit structure of constant current part and cutoff.After Switching Power Supply connects electric main, the direct current that bridge heap rectification circuit exports obtains the high pressure of VPFC after electrochemical capacitor filtering, VPFC voltage is powered to driving chip through start-up circuit, and when the voltage VCC of driving chip reaches the starting resistor of driving chip start, driving chip is started working; After Switching Power Supply is working properly, turns off start-up circuit, powered to driving chip by the auxiliary winding (not shown) of secondary circuit.
The structure of the utility model Switching Power Supply start-up circuit embodiment 1 as shown in Figure 2, comprise input VPFC, output VCC, switching tube Q1 and voltage stabilizing didoe D1, input VPFC connects the positive pole of Switching Power Supply input rectification circuit output, and output VCC connects Switching Power Supply PWM driving chip.
The negative electrode of voltage stabilizing didoe D1 meets input VPFC by resistance R1, and anode meets output VCC; Switching tube Q1 is metal-oxide-semiconductor, and the grid of the metal-oxide-semiconductor Q1 of metal-oxide-semiconductor Q1 connects the negative electrode of voltage stabilizing didoe D1, drains to meet input VPFC by resistance R2, and source electrode meets output VCC by resistance R3.
Input VPFC provides reference voltage to metal-oxide-semiconductor Q1 by resistance R1 and voltage-stabiliser tube D1, make its complete conducting, if voltage during the complete conducting of metal-oxide-semiconductor Q1 between grid level and source electrode is V1, voltage-stabiliser tube voltage stabilizing value is V2, the leakage current of voltage-stabiliser tube D1 is I1, then constant current starting current I=I1+ (V2-V1)/R3.The resistance of regulating resistance R2 makes metal-oxide-semiconductor Q1 drain current Id>I; By selecting the numerical value of voltage-stabiliser tube D1 and resistance R3, just can obtain the starting current needed, and starting current substantially constant is constant, is constant-current source start-up circuit, even if when the voltage of input changes, starting up's time can remain unchanged.
The structure of the utility model Switching Power Supply start-up circuit embodiment 2 as shown in Figure 3, comprises filter capacitor C4 as different from Example 1, and filter capacitor C4 and voltage stabilizing didoe D1 also connects.
The structure of the utility model Switching Power Supply start-up circuit embodiment 3 as shown in Figure 4, as different from Example 2, also comprises breaking circuit and diode D2.Breaking circuit comprises metal-oxide-semiconductor Q2 and bleeder circuit, and bleeder circuit is connected between the output VCC of start-up circuit and ground.Bleeder circuit is made up of the resistance R4 connected and resistance R5, and the drain electrode of metal-oxide-semiconductor Q2 connects the negative electrode of voltage stabilizing didoe D1, source ground connection; Tie point between the grid connecting resistance R4 of metal-oxide-semiconductor Q2 and resistance R5.
The anode of diode D2 connects the anode of voltage stabilizing didoe D1, and negative electrode meets the output VCC of start-up circuit.
When the driving chip of Switching Power Supply starts normally, chip is normally started working and is exported, the voltage VCC of driving chip is by after resistance R4 and R5 dividing potential drop, make the complete conducting of metal-oxide-semiconductor Q2, dragging down the grid step voltage of metal-oxide-semiconductor Q1, making metal-oxide-semiconductor Q1 become cut-off from opening, turn off constant current and start power supply, Switching Power Supply stand-by power consumption is reduced, improved efficiency.
Diode D2 is in order to prevent the voltage source of VCC through voltage-stabiliser tube D1 and metal-oxide-semiconductor Q2 through to ground.
The charging current of the utility model above embodiment Switching Power Supply driving chip controls primarily of voltage-stabiliser tube D1 and resistance R3, and chip charging current is generally between tens μ A to tens μ A, and its consumed power is multiplied by input voltage VPFC, and loss is only in milliwatt level.Even if be used alone constant-current source start-up circuit, also can meet the available machine time requirement of power supply high-low pressure, power standby power consumption requirements can be met again, can ignore on the efficiency impact of the slightly large Switching Power Supply of power, and components and parts reduce, cost-saving, PCB fabric swatch have also been obtained optimization.
Claims (6)
1. a Switching Power Supply start-up circuit, comprise input and output, the positive pole of input termination switch power supply input rectification circuit output, export termination Switching Power Supply PWM driving chip, it is characterized in that, comprise switching tube and voltage stabilizing didoe, the negative electrode of voltage stabilizing didoe connects described input by the first resistance, and anode connects described output; The input described in first termination of switching tube, the second end of switching tube connects described output by the 3rd resistance; The control pole of switching tube connects the negative electrode of voltage stabilizing didoe.
2. Switching Power Supply start-up circuit according to claim 1, is characterized in that, comprises the second resistance, and the first end of switching tube connects described input by the second resistance.
3. Switching Power Supply start-up circuit according to claim 1, is characterized in that, described switching tube is metal-oxide-semiconductor, and the grid of metal-oxide-semiconductor connects the negative electrode of voltage stabilizing didoe, and drain electrode connects described input, and source electrode connects described output by the 3rd resistance.
4. Switching Power Supply start-up circuit according to claim 1, is characterized in that, comprise filter capacitor, and filter capacitor and voltage stabilizing didoe also connect.
5. Switching Power Supply start-up circuit according to claim 1, it is characterized in that, comprise breaking circuit, breaking circuit comprises second switch pipe and bleeder circuit, bleeder circuit is connected between described output and ground, and bleeder circuit comprises the 4th resistance and the 5th resistance of series connection; The negative electrode of the first termination voltage stabilizing didoe of second switch pipe, the second end ground connection; Tie point between control termination the 4th resistance of second switch pipe and the 5th resistance.
6. Switching Power Supply start-up circuit according to claim 1, is characterized in that, comprise diode, and the anode of diode connects the anode of voltage stabilizing didoe, and negative electrode connects described output.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420072289.3U CN204030995U (en) | 2014-02-19 | 2014-02-19 | A kind of Switching Power Supply start-up circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420072289.3U CN204030995U (en) | 2014-02-19 | 2014-02-19 | A kind of Switching Power Supply start-up circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN204030995U true CN204030995U (en) | 2014-12-17 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201420072289.3U Expired - Fee Related CN204030995U (en) | 2014-02-19 | 2014-02-19 | A kind of Switching Power Supply start-up circuit |
Country Status (1)
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| CN (1) | CN204030995U (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104734554A (en) * | 2015-01-19 | 2015-06-24 | 张湘杰 | Power source supercharger and power supply device |
| CN107947556A (en) * | 2017-12-04 | 2018-04-20 | 广州金升阳科技有限公司 | A kind of Switching Power Supply start-up circuit |
| CN109245513A (en) * | 2018-11-09 | 2019-01-18 | 深圳南云微电子有限公司 | A kind of start-up circuit |
| CN110011527A (en) * | 2018-11-30 | 2019-07-12 | 浙江大学台州研究院 | A kind of Switching Power Supply start-up circuit |
-
2014
- 2014-02-19 CN CN201420072289.3U patent/CN204030995U/en not_active Expired - Fee Related
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104734554A (en) * | 2015-01-19 | 2015-06-24 | 张湘杰 | Power source supercharger and power supply device |
| CN107947556A (en) * | 2017-12-04 | 2018-04-20 | 广州金升阳科技有限公司 | A kind of Switching Power Supply start-up circuit |
| CN109245513A (en) * | 2018-11-09 | 2019-01-18 | 深圳南云微电子有限公司 | A kind of start-up circuit |
| CN109245513B (en) * | 2018-11-09 | 2024-04-09 | 深圳南云微电子有限公司 | Starting circuit |
| CN110011527A (en) * | 2018-11-30 | 2019-07-12 | 浙江大学台州研究院 | A kind of Switching Power Supply start-up circuit |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20141217 Termination date: 20190219 |