CN206686087U - The circuit of synchronous rectifier start sequential is controlled in a kind of Switching Power Supply - Google Patents
The circuit of synchronous rectifier start sequential is controlled in a kind of Switching Power Supply Download PDFInfo
- Publication number
- CN206686087U CN206686087U CN201720470565.5U CN201720470565U CN206686087U CN 206686087 U CN206686087 U CN 206686087U CN 201720470565 U CN201720470565 U CN 201720470565U CN 206686087 U CN206686087 U CN 206686087U
- Authority
- CN
- China
- Prior art keywords
- power supply
- circuit
- switching power
- synchronous rectifier
- controlled
- 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.)
- Active
Links
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B70/00—Technologies for an efficient end-user side electric power management and consumption
- Y02B70/10—Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes
Landscapes
- Dc-Dc Converters (AREA)
- Rectifiers (AREA)
Abstract
The utility model provides the circuit that synchronous rectifier start sequential is controlled in a kind of Switching Power Supply, the circuit includes input voltage source, Switching Power Supply primary side and transformer, secondary rectifying circuit, controller line, accessory power supply, output voltage sampling circuit, sampled voltage discharge line, it is characterized in that, the circuit is by the output voltage of sampling switch power supply, and using the characteristic of resistance capacitance discharge lag, the drive signal for carrying out controlling switch pipe is transmitted to the time of synchronous rectifier.The utility model circuit design is simple, and device is few, and cost is low, easily realizes, can effectively reduce Switching Power Supply very big secondary synchronous rectifier stress and anti-sink current caused by unexpected start when output voltage does not drop to zero, adds the reliability of Switching Power Supply.
Description
Technical field
Field of switch power is the utility model is related to, controls synchronous rectifier to start shooting more particularly in a kind of Switching Power Supply
The circuit of sequential.
Background technology
Switching Power Supply is now widely used in modern power electronic system, mainly by some circuit topology frameworks,
Input voltage is converted into satisfactory voltage.And in the transfer process of voltage, it will usually use transformer and main power
Switching tube Mosfet.
In the line construction of Switching Power Supply, switching tube Mosfet and transformer are typically the use that is serially connected, this
Way is because the characteristic that transformer current can not be mutated so that switching tube Mosfet has very high voltage should when shut-off
Power.It is right in order to reduce the voltage stress of switching tube, it is necessary to take the measure that afterflow is depressured in that one end of transformer voltage bounce
Electric current takes the process circuit of some afterflows decompression, switching tube Mosfet stress, will not have a problem under normal circumstances.But
It is to be had been switched off in Mosfet as secondary synchronous rectifier, Switching Power Supply, output end still has voltage in this case, opens
Powered-down source is started shooting suddenly, and Switching Power Supply does not drop to certain value only with capacity load in capacity load voltage in other words
When, Switching Power Supply start, it is most likely that damage secondary synchronous rectifier.Because Switching Power Supply is typically during the machine of rising, all
It can use soft starting mode, and soft starting mode is essentially all using control PWM dutycycles, is transferred to dutycycle during start
Minimum, then slowly deploy dutycycle.This soft starting mode, secondary synchronous rectifier driving PWM duty cycle is adjusted indirectly
Maximum has been arrived, has then slowly been reduced.If certain voltage be present in Switching Power Supply output, synchronous rectifier PWM duty cycle by
Maximum slowly reduces again, and it is very high to may result in synchronous rectifier voltage stress, it is most likely that breakdown synchronous rectifier.
The utility model with regard to Switching Power Supply working outputs do not still have voltage when, it is synchronous whole caused by start suddenly
The problem of flow tube stress is bigger than normal, it is proposed that the circuit of synchronous rectifier start sequential is controlled in a kind of Switching Power Supply.
Utility model content
The technical problem that the utility model solves, which is to provide in a kind of Switching Power Supply, controls synchronous rectifier start sequential
Circuit.
Technical scheme is used by the utility model solves above-mentioned technical problem：Controlled in a kind of Switching Power Supply synchronous whole
The circuit of flow tube start sequential, the circuit include input voltage source, Switching Power Supply primary side and transformer, secondary rectifying circuit, control
Device circuit processed, accessory power supply, output voltage sampling circuit, sampled voltage discharge line, it is characterised in that the circuit passes through sampling
The output voltage of Switching Power Supply, using the characteristic of resistance capacitance discharge lag, the drive signal for carrying out controlling switch pipe is transmitted to synchronization
The time of rectifying tube.
Preferably, the circuit of synchronous rectifier start sequential is controlled in above-mentioned Switching Power Supply, it is characterised in that Switching Power Supply
Transformer by primary side winding, vice-side winding, power supply winding intercouples composition.
Preferably, the circuit of synchronous rectifier start sequential is controlled in above-mentioned Switching Power Supply, it is characterised in that accessory power supply
Obtained by power supply winding and transformer secondary winding coupled.
Preferably, the circuit of synchronous rectifier start sequential is controlled in above-mentioned Switching Power Supply, it is characterised in that output voltage
Sampling circuit one end connects output end voltage, via a first resistor, a second resistance, a 3rd resistor series connection structure
Into.
Preferably, the circuit of synchronous rectifier start sequential is controlled in above-mentioned Switching Power Supply, it is characterised in that 3rd resistor
The tie point that forms sampled voltage discharge line in parallel with first electric capacity.
Preferably, the circuit of synchronous rectifier start sequential is controlled in above-mentioned Switching Power Supply, it is characterised in that second resistance
The second branch road of sampled voltage discharge line is formed with a first switch pipe.
Preferably, the circuit of synchronous rectifier start sequential is controlled in above-mentioned Switching Power Supply, it is characterised in that output voltage
Sampling circuit is connected with a second switch pipe, there is provided the drive signal of second switch pipe, second switch pipe pass through one the 4th
Resistance is connected with the 3rd switching tube, there is provided the 3rd switching tube drive signal.
Preferably, the circuit of synchronous rectifier start sequential is controlled in above-mentioned Switching Power Supply, it is characterised in that the 3rd switch
Pipe is connected with the driver circuit of secondary rectifying circuit, there is provided the drive signal of secondary rectifying tube.
The utility model, which provides, controls synchronous rectifier start sequential in the Switching Power Supply that one simple in construction, cost is low
Scheme, Switching Power Supply can be effectively reduced in start, the stress of secondary synchronous rectifier and anti-sink current add out
The reliability in powered-down source.Make the application of synchronous rectification more extensive, made for the performance boost of new and high technology electronic product
Contribution.
Brief description of the drawings
The conspectus of synchronous rectifier start sequential is controlled in Fig. 1 Switching Power Supplies.
Embodiment
The embodiment of the utility model circuit is provided below in conjunction with the accompanying drawings, to describe technical side of the present utility model in detail
Case.
In Fig. 1, input voltage source supplies electricity to former change and the transformer 10 of Switching Power Supply.10 transformer secondary winding passes through
The rectification of secondary rectifying circuit 20 output supplies electricity to output loading 30.The accessory power supply 50 of Switching Power Supply passes through winding and transformer pair
Side winding coupled obtains, and accessory power supply 50 provides power supply to Switching Power Supply control circuit, enables Switching Power Supply normal work.
PWM/PFM controllers 60 produce drive signal, corresponding drive signal are provided to primary side circuit and secondary circuit respectively, so that 10
It can be worked with 20.In order to reduce stress of the synchronous rectifier in 20 in the machine of rising, the rectifying tube start of control secondary is devised
Circuit 40.40 operation principle is after Switching Power Supply is shut down, to export due to having capacitive load or other reasonses, output voltage is also
There is certain value, do not drop to zero, R3, R4, R5 series connection partial pressure sampling and outputting voltage, the voltage sampled is Mosfet Q2's
Gate, A is named as, A points are high level, and Q2 is open-minded, and Mosfet Q3 gate is pulled down to zero, Q3 control secondary rectifying tubes
Gate, at this moment secondary rectifying tube shut-off, A points have voltage to establish voltage equivalent to electric capacity C2, when Switching Power Supply is started shooting again,
Controller has drive signal to export the Drain to Q3, and it is open-minded that accessory power supply supplies electricity to diode D1, Mosfet Q1, now on C2
Voltage by R5 and R4, two branch roads electric discharges of Q1, when the voltage of A points is also more than the threshold value of Q2 shut-offs, Q2 is constantly in
Opening state, then Q3 is not open-minded so that and secondary rectification is not open-minded, once A points are reduced to the threshold value of Q2 shut-offs, Q2 shut-offs, Q3
Gate have accessory power supply power supply, via D1, R1 is changed into high level, and Q3 is open-minded, and then secondary rectifying tube is open-minded.By this process
As can be seen that what when of synchronous rectifier when sampling and outputting voltage A size and C2 discharge time length have impact on machine
Wait open-minded.The output voltage sampled is bigger, or RC discharge times are longer, and the available machine time of synchronous rectifier is more late, from
And anti-sink current when synchronous rectifier is started shooting is advantageously reduced, the stress of synchronous rectifier is effectively reduced, increases switch electricity
The reliability in source.
Although the foregoing describing specific implementation circuit of the present utility model, it will be appreciated by those of skill in the art that
These are merely illustrative of, and on the premise of without departing substantially from principle of the present utility model and essence, these implementation circuits can be done
Go out various changes or modifications.Therefore, the scope of protection of the utility model is defined by the appended claims.
Claims (8)
1. controlling the circuit of synchronous rectifier start sequential in a kind of Switching Power Supply, the circuit includes input voltage source, switch electricity
Source primary side and transformer, secondary rectifying circuit, controller line, accessory power supply, output voltage sampling circuit, sampled voltage electric discharge
Circuit, it is characterised in that the circuit is by the output voltage of sampling switch power supply, using the characteristic of resistance capacitance discharge lag,
The drive signal for carrying out controlling switch pipe is transmitted to the time of synchronous rectifier.
2. the circuit of synchronous rectifier start sequential is controlled in a kind of Switching Power Supply as claimed in claim 1, it is characterised in that
The transformer of Switching Power Supply is by primary side winding, vice-side winding, and power supply winding intercouples composition.
3. the circuit of synchronous rectifier start sequential is controlled in a kind of Switching Power Supply as claimed in claim 2, it is characterised in that
Accessory power supply is obtained by power supply winding and transformer secondary winding coupled.
4. the circuit of synchronous rectifier start sequential is controlled in a kind of Switching Power Supply as claimed in claim 1, it is characterised in that
Output voltage sampling circuit one end connects output end voltage, via a first resistor, a second resistance, a 3rd resistor
It is in series.
5. the circuit of synchronous rectifier start sequential is controlled in a kind of Switching Power Supply as claimed in claim 1, it is characterised in that
The 3rd resistor tie point that forms sampled voltage discharge line in parallel with first electric capacity.
6. the circuit of synchronous rectifier start sequential is controlled in a kind of Switching Power Supply as claimed in claim 1, it is characterised in that
Second resistance forms the second branch road of sampled voltage discharge line with a first switch pipe.
7. the circuit of synchronous rectifier start sequential is controlled in a kind of Switching Power Supply as claimed in claim 1, it is characterised in that
Output voltage sampling circuit is connected with a second switch pipe, there is provided the drive signal of second switch pipe, second switch pipe pass through
One the 4th resistance is connected with the 3rd switching tube, there is provided the 3rd switching tube drive signal.
8. the circuit of synchronous rectifier start sequential is controlled in a kind of Switching Power Supply as claimed in claim 1, it is characterised in that
3rd switching tube is connected with the driver circuit of secondary rectifying circuit, there is provided the drive signal of secondary rectifying tube.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201720470565.5U CN206686087U (en) | 2017-04-28 | 2017-04-28 | The circuit of synchronous rectifier start sequential is controlled in a kind of Switching Power Supply |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201720470565.5U CN206686087U (en) | 2017-04-28 | 2017-04-28 | The circuit of synchronous rectifier start sequential is controlled in a kind of Switching Power Supply |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN206686087U true CN206686087U (en) | 2017-11-28 |
Family
ID=60406898
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201720470565.5U Active CN206686087U (en) | 2017-04-28 | 2017-04-28 | The circuit of synchronous rectifier start sequential is controlled in a kind of Switching Power Supply |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN206686087U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108054912A (en) * | 2017-12-28 | 2018-05-18 | 深圳市华星光电半导体显示技术有限公司 | PMIC start sequence circuits and PMIC start time sequence determination methods |
-
2017
- 2017-04-28 CN CN201720470565.5U patent/CN206686087U/en active Active
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108054912A (en) * | 2017-12-28 | 2018-05-18 | 深圳市华星光电半导体显示技术有限公司 | PMIC start sequence circuits and PMIC start time sequence determination methods |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN104319983B (en) | A kind of source driving method, drive circuit and Switching Power Supply being used in Switching Power Supply | |
| CN104836421B (en) | The power supply circuit and method of supplying power to of a kind of Switching Power Supply | |
| CN103728572B (en) | A kind of load detection method, detection circuit and apply its switch power supply | |
| CN203071816U (en) | Switching power supply circuit | |
| CN102570785A (en) | Direct-current power supply hot plug slow starting control circuit and control method | |
| CN104218806A (en) | Method and circuit for controlling fly-back switching power supplies of zero-voltage switches | |
| CN106129968A (en) | Resonant converter and overcurrent protection circuit and overcurrent protection method thereof | |
| CN103683861B (en) | A kind of novel thyristor gating circuit | |
| CN102711306B (en) | Impact current eliminating circuit | |
| CN207069897U (en) | Start-up circuit and inverse-excitation type switch power-supply | |
| CN208209812U (en) | A kind of highpowerpulse load power source soft starting device | |
| CN201966801U (en) | Voltage resistance circuit | |
| CN206686087U (en) | The circuit of synchronous rectifier start sequential is controlled in a kind of Switching Power Supply | |
| CN203660880U (en) | Two-stage boost topological circuit | |
| CN107508468A (en) | The control circuit and method and isolation type switching power supply of isolation type switching power supply | |
| CN202135057U (en) | Half-bridge three-level direct current converter | |
| CN104411035B (en) | A kind of LED drive circuit powered without assists winding | |
| CN102185468B (en) | Multiplexing circuit of high-voltage starting switch and Sense FET and switching power supply applying circuit | |
| CN206807283U (en) | A kind of start-up circuit of Switching Power Supply | |
| CN104734496B (en) | A kind of SEPIC feeds buck-boost converter | |
| CN104184331A (en) | Flyback switching power supply | |
| CN105741788A (en) | Backlight drive circuit and display apparatus | |
| CN205726618U (en) | LLC resonant converter circuit in lamp control system | |
| CN207459989U (en) | A kind of start-up circuit of super wide voltage accessory power supply PWM chip | |
| CN104242646B (en) | high frequency DC-DC buck topology and integrated chip and related system |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| CP02 | Change in the address of a patent holder | ||
| CP02 | Change in the address of a patent holder |
Address after: 212000 No.298, daijiamen Road, Zhenjiang high tech Zone, Zhenjiang City, Jiangsu Province Patentee after: JIANGSU ZHAONENG ELECTRONIC CO.,LTD. Address before: No.99, dingmaojing 15th Road, Zhenjiang New District, Zhenjiang City, Jiangsu Province, 212009 Patentee before: JIANGSU ZHAONENG ELECTRONIC CO.,LTD. |