CN104539167B - Synchronous rectification control method of push-pull converter and control chip - Google Patents
Synchronous rectification control method of push-pull converter and control chip Download PDFInfo
- Publication number
- CN104539167B CN104539167B CN201410804413.5A CN201410804413A CN104539167B CN 104539167 B CN104539167 B CN 104539167B CN 201410804413 A CN201410804413 A CN 201410804413A CN 104539167 B CN104539167 B CN 104539167B
- Authority
- CN
- China
- Prior art keywords
- synchronous rectification
- comparator
- port
- switch pipe
- audion
- 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
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M3/00—Conversion of dc power input into dc power output
- H02M3/22—Conversion of dc power input into dc power output with intermediate conversion into ac
- H02M3/24—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters
- H02M3/28—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac
- H02M3/325—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal
- H02M3/335—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only
- H02M3/337—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only in push-pull configuration
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
- H02M7/02—Conversion of ac power input into dc power output without possibility of reversal
- H02M7/04—Conversion of ac power input into dc power output without possibility of reversal by static converters
- H02M7/12—Conversion of ac power input into dc power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
- H02M7/21—Conversion of ac power input into dc power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
- H02M7/217—Conversion of ac power input into dc power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only
-
- 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
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Rectifiers (AREA)
Abstract
The invention provides a synchronous rectification circuit of a push-pull converter and a control method thereof. The voltage on a vice-side winding of a push-pull circuit transformer is detected to achieve synchronous rectification control. The synchronous rectification circuit of the push-pull converter and the control method thereof can effectively solve the countercurrent flow problem of output energy of synchronous rectification under the light load condition, and while it is guaranteed that synchronous rectification improves the product full load efficiency, the light load efficiency of products can also be improved. A synchronous rectification switch tube is connected in advance through the design, the current flowing through a rectification tube body parasitic diode is effectively reduced, and the connecting loss is reduced. Meanwhile, the detection precision can be effectively improved through the method of detecting winding voltages, it is guaranteed that the working state of a synchronous rectification tube is not affected by the magnitude of the current flowing through the rectification tube any more, the reliability of products is improved, and the application range of the synchronous rectification circuit is also greatly increased due to the simple design to the greater limit.
Description
Technical field
The present invention relates to a kind of synchronous rectification control method and control chip, more particularly to one kind is applied to push-pull converter
Synchronous rectification control method and control chip.
Background technology
With the development of power electronics industry, traditional linear power supply gradually by the Switching Power Supply with switching characteristic gradually
Substituted, Switching Power Supply has an efficiency high, the characteristic such as controllable, through years development, Switching Power Supply also occurs in that different circuits are opened up
Flutter, including forward topology, flyback topologies etc., and push-pull topology, the bridge type topology for developing out by forward topology etc., no
Same topology has respective advantage.Wherein push-pull circuit has symmetry characteristic, and its drive signal is symmetrical expression, two main work(
Rate switching tube alternation, by transformator alternative expression to Load transportation energy, magnetic core is operated in first and third quadrant, can have
The reduction volume of transformer of effect, so as to reduce Switching Power Supply volume.Due to the characteristic of its Transformer Winding alternation so that its
More applications are provided with micropower open loop type Switching Power Supply, micropower Switching Power Supply is for the simplicity of design, people
Output it end filter inductance in design to save.
Royer circuits are also a kind of simple push-pull circuit, and its basic functional principle is realized certainly using magnetic saturation characteristic
Impulse and swing, realize two triode alternative expression work, realize the effect of energy transmission.In actual design and debugging process,
There is debugging difficult problem in Royer circuits, be unfavorable for design production.In order to solve the above problems, people begin to use with self-excitation
The control IC of concussion function goes to control the power tube of push-pull circuit, while audion is replaced with into the lower metal-oxide-semiconductor of conduction impedance,
On the one hand circuit debugging efficiency is improve, on the other hand also improves the reliability of product.
In order to further improve the efficiency of circuit, people start to select to be substituted admittedly using the metal-oxide-semiconductor with low conduction impedance
The commutation diode of constant pressure drop, so as to improve the efficiency of circuit, but while also brings some problems, such as devices
Driven management problem, at present the more commonly used has two kinds of drive schemes：
Scheme one, winding self-powered flowing mode is exported using transformator, physical circuit is shown in Fig. 1, its basic functional principle description
It is as follows：When transformer primary side switching tube Q10 is driven to high level, switching tube Q10 is open-minded, and now switching tube Q20 is driven to low
Level, switching tube Q20 shut-offs, now input voltage is added on transformer primary side winding 21, and transformator Same Name of Ends is negative, transformator
Voltage's distribiuting is on vice-side winding：4 ends are higher than 5 ends, and 5 ends are higher than 6 ends, and switching tube Q31 conductings, Transformer Winding 56 to output is negative
Carry and energy is provided.With should transformer primary side switching tube Q20 open when, Q10 turn off when, transformer secondary switching tube Q41 conducting,
Transformer Winding 45 to load provides energy.
But the program is fairly simple to have following two shortcomings：1st, the drive signal of synchronous rectification switch pipe is another right
Claim the voltage on winding, and the driving voltage maximum of switching tube is 20V, that is to say, that the highest of transformer secondary winding 4 to 6
Voltage difference so limits the extensive application of circuit not above 20V；2nd, when circuit is operated in light load, due to synchronization
The reason for rectification drives winding to be clamped, easily there is energy reflux phenomenon in outfan, when so easily causing light load, product
Efficiency is low, loss increase when especially unloaded, causes product heating serious, affects the service life of product.
Scheme two, synchronous rectification control is realized by special control IC, existing market there are many such control IC, its
Ultimate principle is all that real-time detection rectifier switch both end voltage drop realizes control, but the program is typically used only in output current
In larger product, the program cannot be realized in small current output products, and program control IC is substantially more expensive, body
Product is larger to be unfavorable for non-voltage stabilizing small size class products application.
The content of the invention
It is an object of the invention to：A kind of synchronous rectification control method of push-pull converter is provided, it is characterised in that：It is logical
The voltage magnitude that synchronous rectification control chip detects transformer secondary winding is crossed, transformer secondary synchronous rectification switch pipe is controlled
Open sequential, service time and turn-off time to realize that synchronous rectification works.
The course of work of described synchronous rectification control chip is：
The signal detection port V1 of synchronous rectification control chip detect input voltage for negative voltage when, synchronous rectification control
Chip internal timing circuit starts timing, and now signal detection port V2 detects input voltage for positive voltage, synchronous rectification control
Coremaking piece drive signal port G22 exports low level, and drive signal port G11 output high level, transformer secondary the 3rd is synchronous
Rectifier switch pipe is turned on, the synchronous rectification switch pipe of transformer secondary the 4th shut-off, by the vice-side winding of transformator first to load
Energy is provided；After elapsed time t1, drive signal port G11 output low levels, the shut-off synchronous rectification of transformer secondary the 3rd is opened
Guan Guan；
After elapsed time t22, signal detection port V1 detects input voltage for positive voltage, signal detection port V2 detections
When to input voltage being negative voltage, synchronous rectification control chip internal timing circuit restarts timing, synchronous rectification control core
Piece drive signal port G22 exports high level, and drive signal port G11 output low levels, control transformer secondary the 4th is synchronous
Rectifier switch pipe is turned on, and now the synchronous rectification switch pipe of transformer secondary the 3rd is in off state, by transformator pair
The winding of side second to load provides energy；After elapsed time t2, G22 output low levels in drive signal port turn off transformator pair
The synchronous rectification switch pipe of side the 4th；Now the synchronous rectification switch pipe of transformer secondary the 3rd and the 4th synchronous rectification switch pipe are all located
In off state；
After elapsed time t11, it is negative voltage that signal detection port V1 detects input voltage, repeats the above-mentioned course of work,
The synchronous rectification switch pipe of alternate conduction transformer secondary the 3rd and the synchronous rectification switch pipe of transformer secondary the 4th.
Described t1, t2 is respectively the synchronous rectification switch pipe of transformer secondary the 3rd and the synchronous rectification of transformer secondary the 4th
The ON time of switching tube, is set according to synchronous rectification control chip inner parameter, and t1=t2.
When described t1, t2 is respectively less than the driving high level time t of push-pull converter primary-side-control chip output and dead band
Between △ t sums, realize primary side switch pipe conducting before secondary synchronous rectification switch pipe be off state, be not in that energy is anti-
Flow phenomenon.
It is a further object to provide a kind of synchronous rectification control chip of push-pull converter.The purpose is to pass through
What technical scheme below was realized：
A kind of synchronous rectification control chip of push-pull converter, including signal detection port V1 and V2, drive signal port
G11 and G22, feeder ear VCC, earth terminal GND.
Described signal detection port V1 and V2 connects respectively transformator and exports non-voltage stabilizing end；The drive signal port G11
With the grid and the synchronous rectification switch pipe of transformer secondary the 4th that G22 connects respectively transformer secondary the 3rd synchronous rectification switch pipe
Grid, the synchronous rectification switch pipe of driving transformer secondary the 3rd and the synchronous rectification switch pipe alternate conduction of transformer secondary the 4th.
Described power supply side VCC meets transformer secondary positive output port Vo.
Described earth terminal GND ground connection.
Preferably, the synchronous rectification control chip of described a kind of push-pull converter, also including first comparator, the second ratio
Compared with device, the 3rd comparator, the 4th comparator, the 5th comparator, the 6th comparator, the first audion, the second audion, the three or three
It is pole pipe, the 4th audion, the first constant-current source, the second constant-current source, the first electric capacity, the second electric capacity, the first gate-controlled switch, second controllable
Switch.
The positive input port of described first comparator connects signal detection port V1, negative input port ground connection, output port
Connect the base stage of the first audion；The positive input port of the second described comparator meets signal detection port V1, and negative input port connects
Reference voltage V 22, output port connects control end SW1 of the base stage of the second audion and the first gate-controlled switch；First audion
Emitter stage is connected with 1 end of the first constant-current source, and the colelctor electrode of the first audion is connected with the colelctor electrode of the second audion；First is permanent
The 0 termination feeder ear VCC in stream source；The emitter stage of the second audion connects 0 end of the second constant-current source, the 1 end ground connection of the second constant-current source；
The colelctor electrode of one the second audion of termination of the first electric capacity and 1 end of the first gate-controlled switch, another termination second of the first electric capacity
1 end of constant-current source；The positive input terminal of 0 the 3rd comparator of termination of the first gate-controlled switch, the negative input termination base of the 3rd comparator
Quasi- voltage V11, the output termination drive signal port G22 of the 3rd comparator；
The positive input port of the 4th described comparator connects signal detection port V2, negative input port ground connection, output port
Connect the base stage of the 3rd audion；The positive input port of the 5th described comparator meets signal detection port V2, and negative input port connects
Reference voltage V 22, output port connects the base stage of the 4th audion and control end SW2 of the second gate-controlled switch；3rd audion
Emitter stage is connected with 1 end of the first constant-current source, and the colelctor electrode of the 3rd audion is connected with the colelctor electrode of the 4th audion；Four or three
The emitter stage of pole pipe connects 0 end of the second constant-current source；The colelctor electrode and second of one the 4th audion of termination of the second electric capacity controllable is opened
1 end closed, 1 end of the constant-current source of another termination second of the second electric capacity；The 0 of second gate-controlled switch terminates the just defeated of the 6th comparator
Enter end, the negative input termination reference voltage V 11 of the 6th comparator, the output termination drive signal port G11 of the 6th comparator；
Preferably, the synchronous rectification control chip of described a kind of push-pull converter, also including the 5th synchronous rectification switch
Pipe and the 6th synchronous rectification switch pipe, replace the synchronous rectification switch pipe of transformer secondary, simplify external circuit；5th is synchronous whole
The grid of stream switching tube and the grid of the 6th synchronous rectification switch pipe connect respectively the outfan and the 6th comparator of the 3rd comparator
Outfan, the drain electrode of the 5th synchronous rectification switch pipe connects respectively detection port V1, the positive input terminal of first comparator and second
The positive input terminal of comparator, the drain electrode of the 6th synchronous rectification switch pipe connects respectively detection port V2, the positive input of the 4th comparator
End and the positive input terminal of the 5th comparator, the source electrode of the 5th synchronous rectification switch pipe and the source electrode of the 6th synchronous rectification switch pipe connect
Ground.
Described reference voltage V 22 can be adjusted according to design, setting should Δ Vo lower than output voltage, Δ Vo's
Setting scope is 0V-0.7V.Before can realizing that synchronous rectification switch body parasitic diode is opened, the second comparator or the 5th ratio
Overturn in advance compared with device so that drive signal port G11 or G22 export in advance high level, realize opening driven synchronization in advance
Rectifier switch pipe.
The present invention basic thought be：In open loop type push-pull circuit, primary side switch pipe drive control signal is by former limit control
Coremaking piece U1 is produced, and the pulsewidth of control signal is t, there is Dead Time △ t between two path control signal.Secondary synchronous rectification control
Coremaking piece U2 records corresponding winding low level time t11 and t22 by the voltage in special detection foot detection winding, when
When the winding voltage is changed into positive level, synchronous rectifier is opened by control chip U2 output drivings control signal, and in t1 or
Person turns off synchronous rectifier after the t2 times, so alternately records the negative pressure time on correspondence winding, controls synchronous rectifier
ON time so that primary side switch pipe Q1 or Q2 open front secondary synchronous rectification switch pipe Q3 and Q4 all in off state,
Outfan energy reflux is effectively avoided, the efficiency of light load is improve, while the control program is by detecting transformator
Winding voltage, is not limited by output current size, reliably also can realize reliably controlling in the case of small current.
Beneficial effects of the present invention are as follows：
The present invention can effectively solve synchronous rectification and export energy reflux phenomenon in the case of light load, it is ensured that synchronous
While rectification improves product full load efficiency, the light load efficiency of product can be also improved.Can also be realized by design synchronous whole
Stream switching tube is open-minded in advance, effectively reduces the electric current for flowing through rectification body parasitic diode, reduces conduction loss.Pass through simultaneously
The method of detection winding voltage, can effectively improve accuracy of detection, it is ensured that synchronous rectifier working condition is no longer flow through rectification
The impact of the size of current of pipe, improves the reliability of product, because design simply also increased to a greater extent the invention
Range of application.
Description of the drawings
Fig. 1 is self-driving type synchronous rectification push-pull circuit in prior art；
Fig. 2 synchronous rectification control chips of the present invention are applied to the circuit diagram of push-pull converter；
The circuit diagram of synchronous rectification control chip in Fig. 3 embodiment of the present invention；
Coherent signal sequential chart t in Fig. 4 embodiment of the present invention<t12<t+△t；
Coherent signal sequential chart t in Fig. 5 embodiment of the present invention>t12；
Synchronous rectifier is integrated in Fig. 6 present invention the circuit diagram inside synchronous rectification control chip.
Specific embodiment
Embodiment one
Fig. 2 is the circuit diagram that the present invention is applied in push-pull converter, and synchronous rectification control is realized to the present invention with reference to Fig. 2
The course of work of method is explained.
BT is direct-current input power supplying, its negativing ending grounding, and anode is connected with electric capacity C1 one end, and with the VCC of control chip U1
Pin is connected, and is connected with the common tap point 2 of transformator the first winding 12 and the second winding 23, the other end ground connection of electric capacity C1,
The GND pin ground connection of control chip U1, G1 feet are connected with the grid of switching tube Q1, and G2 feet are connected with switching tube Q2 grids, transformation
Device T1 has four windings, respectively winding 12, winding 23, winding 45, winding 56, wherein winding 12, and 23 have one public to take out
Head point 2, winding 45,56 have a common tap point 5, and the drain electrode of 1 termination switching tube Q1 of winding 12,3 terminations of winding 23 are opened
The drain electrode of pipe Q2 is closed, common tap point 2 meets the positive outfan of power supply BT, the source grounding of switching tube Q1, Q2, diode D1
With the body parasitic diode that D2 is respectively switching tube Q1 and Q2.The common tap point 5 of transformator T1 vice-side windings 45 and 56 connects pair
Side positive output Vo end, the drain electrode of 4 termination switching tube Q4 of winding 45 and synchronous rectification control chip U2 detection signal input V2,
The drain electrode of 6 termination switching tube Q3 of winding 56 and synchronous rectification control chip U2 detection signal input V1, switching tube Q3 and Q4
Source electrode be connected with output filter capacitor C2 one end, while connecting load R one end, the grid of switching tube Q3 and Q4 is whole with synchronous respectively
The G11 pins of flow control chip U2 are connected with G22 pins, and output filter capacitor C2 and load R one end are connected and and output plus terminal
Vo is connected, and diode D3 and D4 are respectively switching tube Q3 and Q4 body parasitic diodes.
The operation principle and the course of work of the circuit is described as follows, it is assumed that the circle of tetra- windings of transformator T1 12,23,45,56
Than for 1：1：1：1, it is t that former limit recommends chip U1 output drivings high level time, is existed between two drive signals G1 and G2 dead
Area time △ t, and △ t are much smaller than drive signal high level time t, △ t+t=T/2, wherein T are push-pull circuit drive signal work
Make the cycle.It is high level that former limit recommends control chip U1 output drive signals G1, and G2 is low level, then switching tube Q1 grids are height
Level, switching tube Q2 grids are low level, and switching tube Q1 is open-minded, and power supply BT voltage-drop loadings become in Transformer Winding 21
Voltage gradually rises to V by zero on depressor winding 21BT, final V21=VBT, switching tube Q2 shut-offs, according to Faraday's law of induction,
Induced voltage is respectively and reaches final determination state by a certain uncertain magnitude of voltage on transformation T1 other windings, respectively：V23
=-VBT, V45=VBT, V56=VBT, in winding voltage change procedure, when 6 foot voltages of Transformer Winding 56 were gradually lowered
Cheng Zhong, when 6 foot voltage ratio outfans ground GND1 voltages are low, then the body parasitic diode D of synchronous rectification switch pipe Q33Conducting,
Now the drive signal outfan G11 of synchronous rectification control chip U2 exports high level, and pipe Q3 is open-minded for driving switch, synchronous rectification
Chip U2 internal timing circuits start timing when the signal detection foot V1 of control chip U2 detects the foot of transformator 6 to bear, and drive
Dynamic signal output part G22 now exports low level, and signal detection foot V2 does not now do any detection.Now transformator passes through transformation
Device winding 56 to load provides energy, while charging to electric capacity C2.
Primary-side-control IC output drive signal G1 now drives letter by high step-down, switching tube Q1 shut-offs after elapsed time t
Number G2 is also low level, then primary side switch pipe Q1 and Q2 is off state simultaneously.Secondary synchronous rectification control chip U2 is passed through
Drive signal output pin G11 outputs after a period of time t1 are changed into low level from high level, and synchronous rectification switch pipe Q3 is turned off, then
Now secondary synchronous rectification switch pipe Q3 and Q4 are all in off state.Time, t1 was not more than T/2, if t1 is less than t, switched
After pipe Q3 shut-offs, Q3 body parasitic diodes are still turned on, and winding 56 continues to provide energy to outfan, until Transformer Winding
56 terminal voltages are higher than outfan GND1 voltages, and the cut-off of Q3 bodies parasitic diode so can be achieved with the pair when switching tube Q2 is opened
Side switching tube Q3 and Q4 is off state simultaneously, is not in output energy reflux phenomenon；If t1 is more than t, but less than t+
During △ t, then when Q3 is turned off, Q3 body parasitic diodes end, and so can equally realize that secondary is opened when switching tube Q2 is opened
Close pipe Q3 and Q4 and be off state simultaneously, be not in energy reflux phenomenon.The signal of chip U2 after switching tube Q3 shut-offs
Detection foot V1 detects positive level and stops detection, and tracer signal is detected that the detection time of foot V1 is by chip U2 internal timers
t22.After switching tube Q1 shut-offs after Dead Time △ t, the driving output pin G2 output levels of primary-side-control chip U1 by
Low to uprise, pipe Q2 is open-minded for primary side switch, then the two ends of Transformer Winding 23 gradually become positive level by zero level, and are finally V23=
VBT, and transformator T1 other winding voltages also change, the voltage of winding 12 is changed into V from zeroBT, and winding 45 and 56 is also same
Sample is gradually gradually varied to final stable level by zero level：V45=-VBT, V56=-VBT, in the process of the change in voltage of winding 45
In, but the terminal voltage of winding 4 than output ground GND1 it is low when switching tube Q4 body parasitic diodes it is open-minded, and while synchronous rectification control core
The driving output pin G22 output high level of piece U2, switching tube Q4 is open-minded, and Transformer Winding 45 to secondary load R provides energy, together
When charge to electric capacity C2, the signal detection foot V2 for opening simultaneously chip U2 in Q4 starts to detect the end low level of Transformer Winding 4, Jing
After crossing time t2, synchronous rectification control chip U2 driver controls drive output pin G22 drive levels by high step-down, shut-off switch
Pipe Q4, the time, t2 was not more than T/2, if t2 is less than t, after switching tube Q4 shut-offs, Q4 body parasitic diodes are still turned on, around
Group 45 continues to provide energy to outfan, until the terminal voltage of Transformer Winding 45 is higher than outfan GND1 voltages, Q4 bodies parasitism two
Pole pipe is ended, and so can be achieved with the secondary-side switch pipe Q3 and Q4 when switching tube Q1 is opened while being off state, will not be gone out
Now export energy reflux phenomenon；If t1 is more than t, but during less than t+ △ t, then when Q4 is turned off, Q4 body parasitic diodes end,
So the secondary-side switch pipe Q3 and Q4 when switching tube Q1 is opened can be equally realized while being off state, be not in energy
Reflux phenomenon.Stop detection when the signal detection foot V2 of chip U2 after switching tube Q4 shut-offs detects positive level, inside U2
Tracer signal is detected that the detection time of foot V2 is t11 by timer.
Above-mentioned synchronous rectification control chip U2 has following characteristic, and signal detection foot V1 or V2 is detecting input voltage
For negative value when, timing is started inside U2, while U2 output pin G11 or G22 also export high level, through certain hour t1
Or after t2, control chip U2 correspondences drive output pin G11 or G22 output low level, on-off switching tube Q3 or Q4, letter
Number detection foot V1 or V2 detect incoming level for positive level when stop timing, synchronous rectification switch pipe service time t1 or
Person t2 is respectively less than T/2, so can ensure that secondary rectifier switch pipe Q3 and Q4 before former limit either switch pipe Q1 or Q2 are opened
Be in off state, so as to ensure outfan storage capacitor C2 energy will not reflux so as to cause energy dissipation, improve power supply
Efficiency.
Embodiment two
Figure three is a kind of simplified model of control chip U2 internal circuits in the present invention, the signal detection foot of control chip U2
V1 is connected respectively with the positive input of comparator 1 and comparator 2, and the negative input of comparator 1 is defeated with control chip U2
Go out ground GND1 to be connected, the outfan of comparator 1 is connected with the base stage of audion TR1, emitter stage and the constant-current source 1 of audion TR1
1 end be connected, the colelctor electrode of audion TR1 is connected with electric capacity Cap1 one end, at the same with the colelctor electrode of audion TR2 and controllable open
Close 11 end be connected, 0 end of gate-controlled switch 1 is connected with the positive input of comparator 3, the end SW1 of 1 control end of gate-controlled switch 2 and
The outfan SW1 of comparator 2 is connected.0 end of constant-current source 1 is connected with the feeder ear VCC of U2.The negative input of comparator 2 with
Reference level V22 is connected, and the outfan of comparator 2 is connected with the base stage of audion TR2, the emitter stage of audion TR2 and constant current
0 end in source 2 is connected, and 1 end of constant-current source 2 is connected with the output ground GND1 of control chip U2, while the other end with electric capacity Cap1
It is connected, the negative sense input of comparator 3 is connected with reference level V11, and the outfan of comparator 3 is connected with the G22 ends of control chip.
The signal detection foot V2 of control chip U2 is connected respectively with the positive input of comparator 4 and comparator 5, the negative sense of comparator 4
The output ground GND1 of input and control chip U2, the outfan of comparator 4 is connected with the base stage of audion TR3, audion TR3
Emitter stage be connected with 1 end of constant-current source 1, the colelctor electrode of audion TR3 is connected with electric capacity Cap2 one end, while and audion
The colelctor electrode of TR4,1 end of gate-controlled switch 2 are connected, and 0 end of gate-controlled switch 2 is connected with the positive input of comparator 6, controllable to open
Close the end SW2 of 2 control end 2 to be connected with the outfan SW2 of comparator 5.0 end of constant-current source 1 is connected with the feeder ear VCC of chip U2.
The negative input of comparator 5 is connected with reference level V22, and the outfan of comparator 5 is connected with the base stage of audion TR4, and three
The emitter stage of pole pipe TR4 is connected with 0 end of constant-current source 2, and 1 end of constant-current source 2 is connected with the output ground GND1 of control chip U2, together
When be connected with the other end of electric capacity Cap2, the input of the negative sense of comparator 6 is connected with reference level V11, the outfan of comparator 6 and
The G11 ends of control chip U2 are connected.Wherein reference level V11 and V22 are respectively the internal reference level of U2, be just, according to
Circuit parameter carries out specific design, and constant-current source 1 and constant-current source 2 are equally U2 internal reference constant-current sources, concrete according to design parameter
Design, gate-controlled switch 1 and the difference suspension control signal SW1 and SW2 control of gate-controlled switch 2, and switch during high level open-minded.
Circuit operation principle is described as follows：With reference to Fig. 2 and Fig. 3, when drive output G1 of primary-side-control chip U1 is exported
When level is by low gradually rising, switching tube Q1 is gradually open-minded, and the two ends level of winding 21 of transformator T1 is gradually changed into V from 0BT, then
Transformer Winding 45,56 two ends level also gradually from 0 are changed into VBT, due to the end level of transformator 4 it is higher than 5 ends, so secondary synchronization
Rectifier tube Q4 bodies parasitic diode will not be opened, and the end level of transformator 5 is higher than 6 ends, and 5 ends are just being connected with output, transformator 5
End level is uprised, then the end level of transformator 6 is gradually lowered, when the end level of transformator 6 is lower than output ground GND1, then synchronous rectification
Pipe Q3 body parasitic diodes D3 is turned on, and Transformer Winding 56 provides energy by synchronous rectifier Q3 body parasitic diode D3 to secondary
Amount.And during Transformer Winding change in voltage, two the test sides V1 and V2 of control chip U2 detect respectively corresponding letter
Following action is done after number：After V1 ends detect the end level of transformator 6 less than output ground GND1, the electricity of the positive input of comparator 1
Flat lower than negative sense input, then comparator 1 exports low level, and audion TR1 is open-minded, and constant-current source 1 charges to electric capacity Cap1.Comparator
The level of 2 positive input is lower than negative input, the outfan SW1 of comparator 2 output low levels, and gate-controlled switch 1 is turned off, three
Pole pipe TR2 is turned off, then the positive input level of comparator 3 is lower than negative input, and the outfan G22 of comparator 3 exports low electricity
It is flat, synchronous rectifier Q4 shut-offs.And the both end voltage of winding 45 and the contrast of winding 56, the level at the end of transformator 4 gradually rises,
Then the signal detection foot V2 inputs of control chip U2 are positive level, then the level of the positive input of comparator 4 is input into higher than negative sense
End, the output high level of comparator 4, three-level TR3 is off state.The level of the positive input of comparator 5 compares negative input
Height, the outfan SW2 of comparator 5 is high level, and audion TR4 is open-minded, then electric capacity Cap2 is discharged by constant-current source 2, due to SW2
For high level, then gate-controlled switch 2 is open-minded, and the level of the positive input of comparator 6 is higher than negative input, then comparator 6 is defeated
Go out to hold G11 to be high level, pipe Q3 is open-minded for synchronous rectification switch, realize that synchronous rectifier works, realize Transformer Winding 56 to pair
While powering.Electric capacity Cap2 discharges through constant-current source and causes both end voltage to reach the negative sense base of comparator 6 after a period of time t1
Quasi- level V11, then the outfan G11 of comparator 6 will be changed into low level, synchronous rectification Q3 shut-offs.If the time, t1 was opened less than former limit
Pipe service time t is closed, then the end of Transformer Winding 6 is still low level after switching tube Q3 shut-offs, according to being analyzed above, constant-current source 1 is also
Continue to be charged to electric capacity Cap1, constant-current source 2 continues to be charged to electric capacity Cap2, until the shut-off of former limit drive signal, drive signal enters
Enter Dead Time, the 6 end level of transformator T1 are changed into GND1, and 4 ends remain as high level, be according to V1 inputs are analyzed above
Zero, V2 input is height, then comparator 1 is output as high level, and audion TR1 shut-offs, electric capacity Cap1 stops charging, and comparator 5
Still export high level, electric capacity Cap2 continues to discharge until for zero.If t1 is more than primary side switch pipe service time t, but must be little
In t+ △ t, then after Q3 shut-offs, the 6 end level of transformator T1 are changed into GND1, and 4 ends remain as high level, according to V1 is analyzed above
It is high level that input is zero, V2 inputs, then comparator 1 is output as high level, and audion TR1 pipes shut-off, electric capacity Cap1 stops filling
Electricity, and comparator 5 still exports high level, electric capacity Cap2 continues to discharge until for zero.Time t1 is by electric capacity Cap2 original levels
Vcap2 and capacitor's capacity C2, the current value I2 of constant-current source 2, reference level V1 are determined.The transformator T1 after a period of time t22
6 ends be changed into zero level, the output high level of comparator 1, audion TR1 stops being charged to electric capacity Cap1, then now electric capacity Cap1
Voltage is Vcap1=I1 × t22/C1, and wherein C1 is the capacitance of electric capacity Cap1, and I1 is the size of current of constant-current source 1.
Said process records the end low level time of transformator 6 by electric capacity Cap1, and the end low level time of transformator 6 with it is former
Side switching tube service time is identical, then the time of primary-side-control chip U1 output drivings G1 is recorded by Cap1.By comparator 5
The detection end level of transformator 4, synchronous rectification switch pipe Q3 is open-minded for control, and electric capacity Cap2 is discharged by constant-current source 2, controls
Synchronous rectification switch pipe switch time processed.
When primary-side-control chip U1 drive outputs G2 output level is by low gradually rising, switching tube Q2 is gradually open-minded,
The two ends level of winding 23 of transformator T1 is gradually changed into V from 0BT, then Transformer Winding 45,56 two ends level are also gradually by VBTBecome
For-VBT, because the end level of transformator 6 is higher than 5 ends, so secondary synchronous rectifier Q3 bodies parasitic diode will not be opened, and become
The end of depressor 5 is higher than 4 ends, and 5 ends are just connected with output, and the end level of transformator 5 is uprised, then the end level of transformator 4 is gradually lowered, when
When the end level of transformator 4 is lower than output ground GND1, then synchronous rectifier Q4 bodies parasitic diode D4 conductings, Transformer Winding 45 is led to
Cross synchronous rectifier Q4 body parasitic diode D4 and provide energy to secondary.And during Transformer Winding change in voltage, control
Two the test sides V1 and V2 of chip U2 are detected following action is done after corresponding signal respectively：V2 ends detect the end level of transformation 4
After output ground GND1, the positive input level of comparator 4 is lower than negative sense input, then the output of comparator 4 low level, audion
TR3 is open-minded, and constant-current source 1 charges to electric capacity Cap2.The level of the positive input of comparator 5 is lower than negative input, comparator 5
Outfan SW2 exports low level, and gate-controlled switch 2 is turned off, audion TR4 shut-offs, then the level ratio of the positive input of comparator 6
Negative input is low, the outfan G11 of comparator 6 output low levels, synchronous rectifier Q3 shut-offs.And the both end voltage of winding 45 with around
56 contrasts of group, the level at the end of transformator 6 gradually rises, then the signal detection foot V1 inputs of control chip U2 are positive level,
Then the level of the positive input of comparator 1 is higher than negative input, and the output high level of comparator 1, audion TR1 is off shape
State.The level of the positive input of comparator 2 is higher than negative input, and the outfan SW1 of comparator 2 is high level, audion TR2
Open-minded, then electric capacity Cap1 is discharged by constant-current source 2, due to SW1 be high level, then gate-controlled switch is open-minded, comparator 3 it is positive defeated
Enter end higher than negative input, then the outfan G22 of comparator 3 is high level, and pipe Q4 is open-minded for synchronous rectification switch, realize synchronous whole
Flow tube works, and realizes that Transformer Winding 45 is powered to secondary.Electric capacity Cap1 discharges through constant-current source after a period of time t2
So that both end voltage reaches negative sense reference level V11 of comparator 3, then the outfan G22 of comparator 3 will be changed into low level, synchronous whole
Stream Q4 shut-offs.If time t2 is less than primary side switch pipe service time t, the end of Transformer Winding 4 is still after switching tube Q4 shut-offs
Low level, according to being analyzed above, constant-current source 1 also continues to be charged to electric capacity Cap2, and constant-current source 2 continues to be charged to electric capacity Cap1, directly
Turn off to former limit drive signal, drive signal enters Dead Time, and the 4 end level of transformator T1 are changed into GND1, and 6 ends remain as
High level, according to be analyzed above V2 inputs be zero, V1 inputs for high level, then comparator 4 is output as high level, audion TR3
Pipe is turned off, and electric capacity Cap2 stops charging, and comparator 2 still exports high level, and electric capacity Cap1 continues to discharge until for zero.If t2
More than primary side switch pipe service time t, but t+ △ t are necessarily less than, then after Q1 shut-offs, the 4 end level of transformator T1 are changed into GND1,
It is that zero, V2 inputs are height according to V1 inputs are analyzed above and 6 ends remain as high level, then comparator 4 is output as high level, three
Pole pipe TR3 is turned off, and electric capacity Cap2 stops charging, and comparator 2 still exports high level, and electric capacity Cap1 continues to discharge until for zero.
Time t2 is determined by electric capacity Cap1 original levels Vcap1 and capacitor's capacity C2, the current value I2 of constant-current source 2, reference level V11.
4 ends of transformator T1 are changed into zero level after a period of time t11, and the output high level of comparator 4, audion TR3 stops to electricity
Hold Cap2 to charge, then now electric capacity Cap2 voltages are Vcap2=I1 × t11/C2, wherein C2 is the capacitance of electric capacity Cap2, and I1 is
The size of current of constant-current source 1.
Said process records the end low level time of transformator 4 by electric capacity Cap2, and the end low level time of transformator 4 with it is former
Side switching tube service time is identical, then the time of primary-side-control chip U1 output drivings G2 is recorded by Cap2.By comparator 2
The detection end level of transformator 6, synchronous rectification switch pipe Q4 is open-minded for control, and electric capacity Cap1 is discharged by constant-current source 2, controls
Synchronous rectification switch pipe switch time processed.
By above to the analysis of whole circuitry processes, it can be seen that above-mentioned two process is symmetrical, so foregoing circuit
In the design for the concordance of parameter, in circuit design audion TR1 and TR3 can with the consistent audion of selection parameter,
Audion TR2 consistent with TR4 selection parameters audion, electric capacity Cap1 and electric capacity Cap2 equally can be with the consistent electricity of selection parameter
Hold, can so realize synchronous rectification switch pipe Q3 and Q4 service time t1=t2, electric capacity Cap1 and electric capacity Cap2 charging intervals
T11=t22.When can realize that synchronous rectification switch pipe ON time t1 or t2 are opened less than primary side switch pipe by circuit design
Between t, so as to ensure that secondary synchronous rectifier is not in energy reflux phenomenon completely, improve product efficiency while improve product
The reliability of product.Synchronous rectifier can be realized by arranging the negative input reference voltage V 22 of comparator 2 and comparator 5
Switching tube is open-minded in advance, reduces the conduction loss of synchronous rectification switch body diode, so as to improve power-efficient.
Fig. 4 and Fig. 5 are sequential charts correlation time in the present invention, and wherein t is primary side switch pipe service time, and △ t are former limit
Switching tube Q1 and Q2 open Dead Time, and switching tube Q1 and Q2 drive signal is low level within the time, and t1, t2 are respectively
Secondary synchronous rectifier switch time, make t1=t2=t12.T11, t22 are respectively electric capacity Cap1 and electric capacity Cap2 charging intervals,
Make t11=t22.
Embodiment three
Fig. 6 is the circuit theory diagrams of the synchronous rectification control chip of the embodiment of the present invention three, and unlike embodiment one：
Synchronous rectification switch pipe Q5 and Q6 are integrated with synchronous rectification control chip, the synchronous rectifier of transformer secondary is instead of respectively
Switch Q3 and Q4, can so simplify the circuit layout of push-pull converter, compared with existing synchronous rectification control IC on market,
The complexity of circuit is not only simplify, and the highly integrated volume for also reducing cost, reducing product, improve product
Concordance and reliability.Its annexation is：The grid of Q5 and Q6 connects respectively the output of the outfan of comparator 3 and comparator 6
End, the source electrode of V1 pins and V2 pins, Q5 and Q6 that the drain electrode of Q5 and Q6 connects respectively synchronous rectification control chip connects synchronous rectification
The ground GND1 of control chip.Its course of work is identical with embodiment one, will not be described here.
Embodiments of the present invention not limited to this according to the present invention the above, using the ordinary technical knowledge of this area
And customary means, under the premise of without departing from above-mentioned basic fundamental thought of the invention, being embodied as circuit in the present invention can also do
Go out the modification of other various ways, replace or change, all fall within rights protection scope of the present invention.
Claims (6)
1. a kind of synchronous rectification control method of push-pull converter, by synchronous rectification control chip transformer secondary winding is detected
Voltage magnitude, control transformer secondary synchronous rectification switch pipe to open sequential, service time and turn-off time same to realize
Step rectification work, it is characterised in that：The course of work of described synchronous rectification control chip is as follows：
The signal detection port V1 of synchronous rectification control chip detect input voltage for negative voltage when, synchronous rectification control chip
Internal timing circuit starts timing, and now signal detection port V2 detects input voltage for positive voltage, synchronous rectification control core
Piece drive signal port G22 exports low level, drive signal port G11 output high level, the synchronous rectification of transformer secondary the 3rd
Switching tube is turned on, the shut-off of the synchronous rectification switch pipe of transformer secondary the 4th, is provided to load by the vice-side winding of transformator first
Energy；After elapsed time t1, G11 output low levels in drive signal port turn off the synchronous rectification switch pipe of transformer secondary the 3rd；
After elapsed time t22, it is positive voltage that signal detection port V1 detects input voltage, and signal detection port V2 detects defeated
Enter voltage for negative voltage when, synchronous rectification control chip internal timing circuit restarts timing, and synchronous rectification control chip drives
Dynamic signal port G22 exports high level, and G11 output low levels in drive signal port control the synchronous rectification of transformer secondary the 4th
Switching tube is turned on, and now the synchronous rectification switch pipe of transformer secondary the 3rd is in off state, by transformer secondary the
Two windings to load provides energy；After elapsed time t2, drive signal port G22 output low levels, shut-off transformer secondary the
Four synchronous rectification switch pipes；Now the synchronous rectification switch pipe of transformer secondary the 3rd and the 4th synchronous rectification switch pipe are all in pass
Disconnected state；
After elapsed time t11, it is negative voltage that signal detection port V1 detects input voltage, and the above-mentioned course of work of repetition replaces
The conducting synchronous rectification switch pipe of transformer secondary the 3rd and the synchronous rectification switch pipe of transformer secondary the 4th；
Described t1, t2 is respectively less than the driving high level time t and Dead Time △ t of push-pull converter primary-side-control chip output
Sum, realizes secondary synchronous rectification switch pipe before the conducting of primary side switch pipe and is off state, is not in that energy reflux shows
As.
2. the synchronous rectification control method of a kind of push-pull converter according to claim 1, it is characterised in that：Described
When t1, t2 are respectively the conductings of the synchronous rectification switch pipe of transformer secondary the 3rd and the synchronous rectification switch pipe of transformer secondary the 4th
Between, it is to be set according to synchronous rectification control chip inner parameter, and t1=t2.
3. the synchronous rectification control chip of a kind of push-pull converter, it is characterised in that：Including signal detection port V1 and V2, driving
Signal port G11 and G22, feeder ear VCC, earth terminal GND, first comparator, the second comparator, the 3rd comparator, the 4th ratio
Compared with device, the 5th comparator, the 6th comparator, the first audion, the second audion, the 3rd audion, the 4th audion, first permanent
Stream source, the second constant-current source, the first electric capacity, the second electric capacity, the first gate-controlled switch, the second gate-controlled switch；
Described signal detection port V1 and V2 connects respectively transformator and exports non-voltage stabilizing end, for detecting transformator output port
Voltage magnitude；Drive signal the port G11 and G22 connect respectively grid and the change of the synchronous rectification switch pipe of transformer secondary the 3rd
The grid of the synchronous rectification switch pipe of depressor secondary the 4th, the synchronous rectification switch pipe of driving transformer secondary the 3rd and transformer secondary
4th synchronous rectification switch pipe alternate conduction；Described feeder ear VCC meets transformer secondary positive output port Vo；Described ground connection
End GND ground connection；
The positive input port of described first comparator meets described signal detection port V1, described first comparator it is negative defeated
Inbound port is grounded, and the output port of described first comparator connects the base stage of the first described audion；Described second is compared
The positive input port of device meets signal detection port V1, and the negative input port of the second described comparator connects reference voltage V 22, described
The output port of the second comparator connect the base stage and the control end of the first described gate-controlled switch of the second described audion
SW1；The emitter stage of the first described audion is connected with 1 end of the first described constant-current source, the collection of described the first audion
Electrode is connected with the colelctor electrode of the second described audion；0 termination feeder ear VCC of the first described constant-current source；Described
The emitter stage of two audions connects 0 end of the second described constant-current source, and 1 end of the second described constant-current source is grounded；Described first
The colelctor electrode of one termination second audion of electric capacity and 1 end of first gate-controlled switch, first electric capacity it is another
Terminate 1 end of second constant-current source；The positive input terminal of 0 termination the 3rd comparator of first gate-controlled switch, it is described
The negative input termination reference voltage V 11 of the 3rd comparator, the drive signal port described in the output termination of the 3rd comparator
G22；
The positive input port of the 4th described comparator meets described signal detection port V2, described the 4th comparator it is negative defeated
Inbound port is grounded, and the output port of the 4th described comparator connects the base stage of the 3rd audion；The 5th described comparator
Positive input port meet described signal detection port V2, the negative input port of the 5th described comparator connects reference voltage V 22,
The output port of the 5th described comparator connects the control end of the base stage and second gate-controlled switch of the 4th audion
SW2；The emitter stage of the 3rd described audion is connected with 1 end of the first described constant-current source, the collection of described the 3rd audion
Electrode is connected with the colelctor electrode of the 4th described audion；The emitter stage of the 4th described audion connects the second described constant-current source
0 end；The colelctor electrode of the 4th audion described in one termination of the second described electric capacity and the 1 of the second described gate-controlled switch
End, 1 end of the second constant-current source described in another termination of described the second electric capacity；0 termination institute of the second described gate-controlled switch
The positive input terminal of the 6th comparator stated, the negative input of the 6th described comparator terminates reference voltage V 11, the 6th described ratio
The drive signal port G11 described compared with the output termination of device.
4. the synchronous rectification control chip of a kind of push-pull converter according to claim 3, it is characterised in that：Also include the
Five synchronous rectification switch pipes and the 6th synchronous rectification switch pipe, replace the 3rd synchronous rectification switch pipe and the 4th of transformer secondary
Synchronous rectification switch pipe, simplifies external circuit；The grid of the 5th described synchronous rectification switch pipe and the 6th described synchronization are whole
The grid of stream switching tube connects respectively the outfan and the outfan of the 6th described comparator of the 3rd described comparator, described
The drain electrode of the 5th synchronous rectification switch pipe connects respectively detection port V1, the positive input terminal of described first comparator and described the
The positive input terminal of two comparators, the drain electrode of the 6th described synchronous rectification switch pipe connect respectively detection port V2, the described the 4th
The positive input terminal of the positive input terminal of comparator and the 5th described comparator, the source electrode of described the 5th synchronous rectification switch pipe and
The source ground of the 6th described synchronous rectification switch pipe.
5. the synchronous rectification control chip of a kind of push-pull converter according to claim 3, it is characterised in that：Described base
Quasi- voltage V22 is adjusted according to design, its value should Δ Vo lower than output voltage Vo, realize synchronous rectification switch body parasitism two
Before pole pipe is opened so that described the second comparator or the 5th described comparator overturns in advance, and then cause described driving
Signal port G11 or G22 export in advance high level, realize opening driven synchronous rectification switch pipe in advance.
6. the synchronous rectification control chip of a kind of push-pull converter according to claim 5, it is characterised in that：Described Δ
The general intervals of Vo are 0V to 0.7V.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410804413.5A CN104539167B (en) | 2014-12-19 | 2014-12-19 | Synchronous rectification control method of push-pull converter and control chip |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410804413.5A CN104539167B (en) | 2014-12-19 | 2014-12-19 | Synchronous rectification control method of push-pull converter and control chip |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN104539167A CN104539167A (en) | 2015-04-22 |
| CN104539167B true CN104539167B (en) | 2017-04-19 |
Family
ID=52854654
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201410804413.5A Active CN104539167B (en) | 2014-12-19 | 2014-12-19 | Synchronous rectification control method of push-pull converter and control chip |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN104539167B (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105515397A (en) * | 2016-02-05 | 2016-04-20 | 航天长峰朝阳电源有限公司 | Double-excitation synchronous non-inductive rectifying circuit |
| CN106658863A (en) * | 2017-01-20 | 2017-05-10 | 湖南炬神电子有限公司 | High-reliability and long-service life synchronous rectifier power supply |
| CN108880273B (en) * | 2018-09-19 | 2023-11-28 | 重庆线易电子科技有限责任公司 | Push-pull type power converter control circuit |
| CN109217682B (en) * | 2018-09-19 | 2023-11-28 | 重庆线易电子科技有限责任公司 | Push-pull type power converter |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH11308862A (en) * | 1998-04-24 | 1999-11-05 | Nec Fukushima Ltd | Switching power supply circuit |
| JP2001346380A (en) * | 2000-06-01 | 2001-12-14 | Matsushita Electric Ind Co Ltd | Switching power supply |
| CN1571255A (en) * | 2004-04-30 | 2005-01-26 | 艾默生网络能源有限公司 | Synchronous rectification reverse-flow preventing circuit and method for parallel synchronous rectification converter |
| CN101588138A (en) * | 2009-06-22 | 2009-11-25 | 英飞特电子（杭州）有限公司 | Synchronous rectification driving circuit suitable for central tapped structure rectifying circuit |
| CN102157920A (en) * | 2011-03-18 | 2011-08-17 | 华为技术有限公司 | Synchronous rectification control circuit and control method thereof |
| CN202586786U (en) * | 2012-05-15 | 2012-12-05 | 东华大学 | Synchronous rectification circuit based on synchronous rectification chip low-voltage-output push-pull converter |
| CN103312131A (en) * | 2013-07-03 | 2013-09-18 | 华东交通大学 | High-frequency direct-current converter switch tube turn-off speed real-time adjustment method |
| CN203883693U (en) * | 2014-06-06 | 2014-10-15 | 河北汇能欣源电子技术有限公司 | Switching inductive current-type synchronous rectifying circuit with phase compensation function |
-
2014
- 2014-12-19 CN CN201410804413.5A patent/CN104539167B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH11308862A (en) * | 1998-04-24 | 1999-11-05 | Nec Fukushima Ltd | Switching power supply circuit |
| JP2001346380A (en) * | 2000-06-01 | 2001-12-14 | Matsushita Electric Ind Co Ltd | Switching power supply |
| CN1571255A (en) * | 2004-04-30 | 2005-01-26 | 艾默生网络能源有限公司 | Synchronous rectification reverse-flow preventing circuit and method for parallel synchronous rectification converter |
| CN101588138A (en) * | 2009-06-22 | 2009-11-25 | 英飞特电子（杭州）有限公司 | Synchronous rectification driving circuit suitable for central tapped structure rectifying circuit |
| CN102157920A (en) * | 2011-03-18 | 2011-08-17 | 华为技术有限公司 | Synchronous rectification control circuit and control method thereof |
| CN202586786U (en) * | 2012-05-15 | 2012-12-05 | 东华大学 | Synchronous rectification circuit based on synchronous rectification chip low-voltage-output push-pull converter |
| CN103312131A (en) * | 2013-07-03 | 2013-09-18 | 华东交通大学 | High-frequency direct-current converter switch tube turn-off speed real-time adjustment method |
| CN203883693U (en) * | 2014-06-06 | 2014-10-15 | 河北汇能欣源电子技术有限公司 | Switching inductive current-type synchronous rectifying circuit with phase compensation function |
Also Published As
| Publication number | Publication date |
|---|---|
| CN104539167A (en) | 2015-04-22 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102983760B (en) | Flyback switching power system and constant current controller thereof | |
| CN102832792B (en) | Source electrode driving control circuit and control method thereof | |
| CN103546047B (en) | A kind of circuit of synchronous rectification and Switching Power Supply being applicable to electronic transformer | |
| CN101860189B (en) | Bridgeless power factor correcting circuit for critical continuous current mode and method thereof | |
| CN103795260A (en) | Non-complementary flyback active clamp converter | |
| CN103424602B (en) | Based on the secondary winding current testing circuit of source drive | |
| CN110311572A (en) | A kind of transformer isolation drive control method and its isolated drive circuit | |
| CN104539167B (en) | Synchronous rectification control method of push-pull converter and control chip | |
| CN203167339U (en) | LED drive circuit without auxiliary winding | |
| CN103825469A (en) | Control circuit for isolated type convertor and isolated type convertor | |
| CN205070828U (en) | AC -DC single -stage control chip and control system thereof | |
| CN102280990B (en) | Magnetic isolation driving circuit | |
| CN202759634U (en) | LED drive circuit without auxiliary winding | |
| CN205249037U (en) | Switch triode from supply circuit , LED drive module and integrated circuit | |
| CN202586786U (en) | Synchronous rectification circuit based on synchronous rectification chip low-voltage-output push-pull converter | |
| CN104539177B (en) | Synchronous rectification drive circuit and synchronous rectification method of switching power supply | |
| CN206962707U (en) | A kind of dynamic compesated control circuit for synchronous rectification power inverter | |
| CN106100295B (en) | A kind of switching device driving circuit kept based on charge | |
| CN203883691U (en) | Current zero-crossing point detection circuit, drive circuit, and switching power supply | |
| CN203206529U (en) | A LED driving circuit sampling inductive current in a complete period | |
| CN109245498A (en) | A kind of double-transistor flyback Topology Switch power circuit for realizing driving using transformer leakage inductance | |
| CN201557044U (en) | Frequency limited circuit capable of controlling power factor correcting circuit via critical current | |
| CN203595790U (en) | Passive switch isolation detection apparatus | |
| CN108631580A (en) | A kind of current sampling circuit and without bridge commutation system | |
| CN203368305U (en) | Driving circuit of IGBT module power switch |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |