CN100547897C - The control circuit that is used for the synchronous rectifier of forward power transducer - Google Patents
The control circuit that is used for the synchronous rectifier of forward power transducer Download PDFInfo
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- CN100547897C CN100547897C CNB200610001513XA CN200610001513A CN100547897C CN 100547897 C CN100547897 C CN 100547897C CN B200610001513X A CNB200610001513X A CN B200610001513XA CN 200610001513 A CN200610001513 A CN 200610001513A CN 100547897 C CN100547897 C CN 100547897C
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Abstract
The invention provides a kind of circuit of synchronous rectification of forward power transducer.Secondary winding of transformer comprises the first terminal and second terminal that is used to produce switched voltage.One satiable inductor device is couple to the 3rd terminal so that to be provided time of delay from second terminal of Secondary winding of transformer.The first transistor is couple to earth terminal from the first terminal of Secondary winding of transformer.Transistor seconds is connected to earth terminal from the 3rd terminal.The first transistor and transistor seconds are as synchronous rectifier.One inductor is coupled between the lead-out terminal of the 3rd terminal and forward power transducer.In addition, a current sensing device responds the switch current of inductor and produces current signal.One control circuit receives switched voltage and current signal is respectively applied for a plurality of transistorized a plurality of signals of driving with generation.A diode, it is connected to the 3rd terminal from described control circuit, to detect the voltage of transistor seconds between the 3rd terminal and earth terminal.
Description
Technical field
The present invention relates to a kind of control circuit of forward power transducer, more specifically, relate to a kind of synchronous rectifier control circuit that improves the forward power transducer of power converter efficient.
Background technology
Power converter is usually used in unadjusted power conversion is become constant voltage source and/or constant current source.Transformer with an elementary winding and a level winding is generally used for power converter.In a typical case used, elementary winding was couple to a unadjusted dc voltage power supply, and a switching device shifter is connected to elementary winding with conducting and the conduction between dc voltage power supply and elementary winding.One rectifier diode is connected to secondary winding being rectified into direct voltage from the energy that elementary winding conversion comes.Yet, but cause inevitable conduction loss in the forward drop at rectifier diode two ends, and make rectifier diode become the key component that produces loss.For solving power dissipation concerns, adopt the low on-resistance transistor to replace synchronous rectification (SynchronousRectifying) technology of rectifier diode and power application converter mostly.Recently, Edgar Abdoulin is at the United States Patent (USP) the 6th that is entitled as " Single ended forwardconverter with synchronous rectification and delay circuit inphase-locked loop ", a kind of synchronous rectification is proposed in 026, No. 005.Yet the shortcoming of above-mentioned existing synchronous rectification is can reduce power efficiency under light-load conditions.In addition, at the heavy duty duration of work cross-conduction may take place.
Fig. 1 illustrates that one has the existing forward power transducer of synchronous rectifier.Forward power transducer comprises a transformer 10, a plurality of switching device shifter 20,30, and a plurality of switching device shifters 20,30 are used to be controlled at the elementary winding and an input voltage source V of transformer 10
INBetween conduction.Use a plurality of diodes 25 and 35 inductance energies and be recovered to input voltage source V elementary winding
INBe connected to the secondary winding of transformer 10 as two transistors 60,70 of synchronous rectifier.The first transistor 60 is coupled between the first terminal and an earth terminal of secondary winding.Transistor seconds 70 is connected to earth terminal from second terminal of secondary winding.One inductor 80 is coupled between the lead-out terminal of second terminal of secondary winding and power converter.One output capacitance 85 is connected between the lead-out terminal and earth terminal of power converter.
Figure 1A illustrates the initial shift of existing power converter.In this stage, conducting switching device shifter 20 and 30 with via transformer 10 and inductor 80 from input voltage source V
INLead-out terminal conduction energy to power converter.Transistor 60 conducting after its parasitic diode 65 conductings is as synchronous rectifier.
Figure 1B illustrates second working stage of existing power converter.In this stage, after switching device shifter 20,30 ends.Be stored in energy in the inductor 80 via the parasitic diode 75 of transistor 70 to lead-out terminal continuous discharge.Transistor 70 conducting after its parasitic diode 75 conductings is as synchronous rectifier.
Forward power transducer has two kinds of different mode of operations usually, promptly discontinuous mode of operation and continuous operation mode.In continuous operation mode, energy still remains in the inductor 80, that is, reached before zero at the electric current that discharges from inductor 80, and following one-period will just have begun.Because during second working stage, transistor 70 is switched on as synchronous rectifier, so, cross-conduction may take place after following one-period begins, as illustrated among Fig. 2 A, wherein will make the secondary winding short circuit via transistor 70 and parasitic diode 65.During cross-conduction, will produce electromagnetic interference (electromagneticinterference), and will seriously reduce the useful life of transistor 70,60.On the contrary, in discontinuous mode of operation, before following one-period begins, be stored in all energy in the inductor 80 and be released fully and finish.Therefore, do not have induced voltage to remain in the inductor 80 and stop that the energy discharge of output capacitor 85 gets back to transformer 10.
As illustrated among Fig. 2 B, when power converter is in the discontinuous mode of operation under light-load conditions, discharged fully switching moment inductor 80 energy, and reverse current will discharge into transformer 10 from output capacitor 85.Reverse current produces power loss and significantly reduces the efficient of Power Conversion.The purpose of this invention is to provide a kind of control circuit that is used for synchronous rectification, it all has higher operating efficiency under continuous operation mode and discontinuous mode of operation.
Summary of the invention
The synchronous rectification of one circuit supply force transducer comprises that one has the transformer of an elementary winding and a level winding.Secondary winding comprises the first terminal and second terminal.When switching transformer, between second terminal of Secondary winding of transformer and the first terminal, produce switched voltage.One satiable inductor device is couple to the 3rd terminal from second terminal of transformer secondary output winding.One the first transistor is couple to an earth terminal from the first terminal of Secondary winding of transformer.In addition, a transistor seconds is couple to earth terminal from the 3rd terminal.The first transistor and transistor seconds are as synchronous rectifier.One inductor is couple to the lead-out terminal of power converter from the 3rd terminal.In addition, a current sensing device responds a switching electric current of inductor and produces a current signal.One control circuit is connected to the 3rd terminal and receives switched voltage and current signal, is respectively applied for first control signal and second control signal that drives the first transistor and transistor seconds with generation.The satiable inductor device provides a time of delay, and it is used for suppressing to flow to from second terminal of Secondary winding of transformer the electric current of transistor seconds when switched voltage produces.In addition, a diode is connected to the 3rd terminal from control circuit, and it is used to detect the voltage on the 3rd terminal and second control signal is provided.After described switched voltage was higher than one first thresholding, described first control signal promptly was activated; When described switched voltage is lower than one second thresholding, described first control signal is promptly disabled; When the described voltage of described transistor seconds between described the 3rd terminal and described earth terminal is lower than one the 4th thresholding, described second control signal promptly is activated; When described current signal is lower than one the 5th thresholding or described switched voltage is higher than described second thresholding, described second control signal is promptly disabled.
The present invention also provides a kind of synchronous rectifier circuit that is used for a power converter, it is characterized in that comprising: a first transistor, and its first terminal from a level winding of a transformer is couple to an earth terminal; One transistor seconds, it is couple to described earth terminal from one the 3rd terminal; One satiable inductor device, its one second terminal with the described secondary winding of described transformer is connected to described the 3rd terminal; Wherein when switching described transformer, produce one at the described secondary winding two ends of described transformer and switch voltage; One inductor, it is couple to a lead-out terminal of described power converter from described the 3rd terminal; One current sensing device, it responds one of described inductor and switches electric current and produce a current signal; One control circuit, it is respectively applied for one first control signal and one second control signal that drives described the first transistor and described transistor seconds in order to receive described switched voltage and described current signal with generation; And a diode, it is connected to described the 3rd terminal from described control circuit, to detect the voltage of described transistor seconds between described the 3rd terminal and described earth terminal; Wherein after described switched voltage was higher than one first thresholding, described first control signal promptly was activated; When described switched voltage is lower than one second thresholding, described first control signal is promptly disabled; When the described voltage of described transistor seconds between described the 3rd terminal and described earth terminal is lower than one the 4th thresholding, described second control signal promptly is activated; When described current signal is lower than one the 5th thresholding or described switched voltage is higher than described second thresholding, described second control signal is promptly disabled.
The present invention also provides a kind of circuit of synchronous rectification that is used for a power converter, it is characterized in that comprising: one first switch, and its first terminal from a level winding of a transformer is couple to an earth terminal; One second switch, it is couple to described earth terminal from one the 3rd terminal; One satiable inductor device, its one second terminal with the described secondary winding of described transformer is connected to described the 3rd terminal; Wherein when switching described transformer, will produce one at described secondary winding two ends and switch voltage; One inductor, it is couple to a lead-out terminal of described power converter from described the 3rd terminal; One current sensing device, it responds one of described inductor and switches electric current and produce a current signal; One control circuit, it receives described switched voltage and described current signal, is respectively applied for one first control signal and one second control signal that drives described first switch and described second switch with generation; And a diode, it is connected to described the 3rd terminal from described control circuit, to detect the voltage of described second switch between described the 3rd terminal and described earth terminal; Wherein after described switched voltage was higher than one first thresholding, described first control signal promptly was activated; When described switched voltage is lower than one second thresholding, described first control signal is promptly disabled; When the described voltage of described second switch between described the 3rd terminal and described earth terminal is lower than one the 4th thresholding, described second control signal promptly is activated; When described current signal is lower than one the 5th thresholding or described switched voltage is higher than described second thresholding, described second control signal is promptly disabled.
Description of drawings
Accompanying drawing be used for further understanding of the present invention, indivisible with specification, be the part that specification is formed.Accompanying drawing has been represented embodiments of the invention, is used for explaining principle of the present invention with specification.
Fig. 1 illustrates that one has the existing forward power transducer of synchronous rectifier.
Figure 1A illustrates the initial shift of existing power converter.
Figure 1B illustrates second working stage of existing power converter.
The cross-conduction operation of the existing power converter of Fig. 2 A explanation in continuous operation mode.
Existing power converter that Fig. 2 B explanation is operated in discontinuous mode of operation during light-load conditions and the reverse current discharge operation from the output capacitor to the transformer.
Fig. 3 is the schematic diagram according to the circuit of synchronous rectification of the first embodiment of the present invention.
Fig. 4 explanation produces the control circuit of drive signal for synchronous rectifier according to the first embodiment of the present invention.
Fig. 5 explanation is used for a plurality of key waveforms of synchronous rectification of the power converter of continuous operation mode according to the first embodiment of the present invention.
Fig. 6 explanation is used for a plurality of key waveforms of synchronous rectification of the power converter of discontinuous mode of operation according to the first embodiment of the present invention.
Fig. 7 explanation circuit of synchronous rectification according to a second embodiment of the present invention.
Fig. 8 illustrates the circuit of synchronous rectification of a third embodiment in accordance with the invention.
Fig. 9 illustrates that a third embodiment in accordance with the invention comprises that one is used to produce the current sensing device of the current transformer of current signal.
Embodiment
Fig. 3 explanation is according to the circuit of synchronous rectification of the first embodiment of the present invention.Foregoing circuit comprises that one has the transformer 10 of an elementary winding and a level winding.Secondary winding comprises a first terminal and one second terminal.The switching of response transformer 10 produces switched voltage V between second terminal of secondary winding and the first terminal
SOne satiable inductor device 50 is connected to one the 3rd terminal from second terminal of secondary winding.One transistor 60 is connected to earth terminal from the first terminal of secondary winding.One transistor 70 is connected to earth terminal from the 3rd terminal.One inductor 80 is connected to the lead-out terminal of power converter from the 3rd terminal, to produce output voltage V
0One current sensing device response switch current I
SWAnd produce a current signal.One control circuit 100 is used for conduction and cut-off transistor 60 and 70.Control circuit 100 receives switched voltage V
SAnd current signal, in order to produce respectively one first control signal S in order to driving transistors 60 and transistor 70
1With one second control signal S
2Control circuit 100 comprises that a DET+ terminal and that is connected to secondary winding second terminal is connected to the DET-terminal of secondary winding the first terminal.The GND terminal of control circuit 100 is connected to the ground connection reference.Control circuit 100 more comprises IN1 terminal and IN2 terminal, lead-out terminal OUT1 and lead-out terminal OUT2.The IN1 terminal of control circuit 100 is connected to the 3rd terminal via a diode 90, to detect the voltage V of transistor 70 between the 3rd terminal and earth terminal
EThe IN2 terminal is used for sensed current signal.Lead-out terminal OUT1 and OUT2 produce the first control signal S1 and the second control signal S2 that is respectively applied for switching transistor 60 and 70.When switching signal produces, the electric current of transformer 10 the flow through lead-out terminal and the diode 65 of satiable inductor device 50, inductor 80, power converter.Diode 65 can be the parasitic diode and/or the external diode of transistor 60.When switching signal produces, satiable inductor device 50 provide one time of delay T
D, it suppresses to flow to from transformer 10 electric current and the protective transistor 70 of transistor 70.
First embodiment of Fig. 4 explanation control circuit 100 according to the present invention, control circuit 100 comprises a comparator 110, a positive input terminal of comparator 110 is connected to the DET+ terminal via a thresholding (threshold) 120.The DET+ terminal more is couple to second terminal of transformer 10 secondary winding via a resistor 40.The negative input end of comparator 110 is connected to the DET-terminal.The DET-terminal more via a resistor 45 be couple to transformer 10 secondary winding the first terminal.One positive input terminal of one comparator 111 is couple to the DET+ terminal via a thresholding 123.One negative input end of comparator 111 is connected to the DET-terminal.One positive input terminal of one comparator 112 is couple to the DET-terminal via a thresholding 125.One negative input end of comparator 112 is connected to the DET+ terminal.One positive input terminal of one comparator 115 is couple to a thresholding V
R1One negative input end of comparator 115 is couple to the IN1 terminal.The IN1 terminal more is couple to the 3rd terminal to detect the voltage of transistor 70.One current source 129 is couple to the negative input end of comparator 115.One positive input terminal of one comparator 116 is connected to a thresholding V
R2The negative input end of comparator 116 is connected to the IN2 terminal with the received current signal.One trigger 155 produces the first control signal S
1, the first control signal S wherein
1Enable and forbid by comparator 110 by comparator 111.Trigger 156 produces the second control signal S
2The second control signal S wherein
2By 112 with comparator 115 is enabled and by comparator 111 or comparator 116 forbiddings.One circuit comprise a plurality of with the door 160,161 and a plurality of inverter 162,163 be used for guaranteeing enabling the first control signal S
1Forbid the second control signal S before
2, and guarantee enabling the second control signal S
2Forbid the first control signal S before
1
Therefore, at switched voltage V
SAfter being higher than thresholding 120, the first control signal S
1Promptly enable.In case switched voltage V
SBe lower than thresholding 123, the first control signal S
1Promptly forbid.In case the voltage V of transistor 70
EBe lower than thresholding V
R1And switched voltage V
SBe lower than thresholding 125, the second control signal S
2Promptly enable.As long as current signal is lower than thresholding V
R2And/or switched voltage V
SBe higher than thresholding 123, the second control signal S
2Promptly forbid.
Fig. 5 illustrates the key waveforms of the synchronous rectification of working according to first embodiment of the invention in continuous operation mode.Before next switching cycle began, inductor 80 still kept energy.Satiable inductor device 50 provide time of delay T
DAt T time of delay
DDuring this time, switched voltage V
SRestrained and be delivered to the 3rd terminal and switch current I
SWRestrained from transformer 10 and flowed out.Therefore, at switch current I
SWBefore the beginning, but "off" transistor 70.
Fig. 6 illustrates the key waveforms of the synchronous rectification of working according to the first embodiment of the present invention in discontinuous mode of operation.At switched voltage V
STo before inductor 80 chargings, inductor 80 energy stored discharge fully once more.Discontinuous mode of operation generally is used under underload and the no-load condition.Be discharged into before zero at inductor 80, make transistor 70 end, discharge via transistor 70 with the energy that under the situation of underload work, prevents capacitor 85.
Fig. 7 illustrates the second embodiment of the present invention.In order to making current sensing device, it is in order to switch current I with resistor 95 for this embodiment
SWBeing converted to voltage signal uses for control circuit 100.Fig. 8 illustrates the circuit of a third embodiment in accordance with the invention.Equip a current sensing device 200 with switch current I
SWBe converted to voltage signal.Fig. 9 explanation is according to the current sensing device 200 of embodiments of the invention shown in Figure 8.Current sensing device 200 comprises a current transformer 15, a plurality of diode 210～213, a resistor 215 and a capacitor 220.Current sensing device 200 conversion switch current I
SWAnd produce a signal for the I N2 terminal of control circuit 100.
Do not depart from the scope of the present invention or the situation of thought under, can carry out various changes and improvement to structure of the present invention, this is conspicuous for the person of ordinary skill in the field.As previously mentioned, various improvement of the present invention and variation have been contained in the present invention, as long as they are in the scope of claim and equivalent thereof.
Claims (9)
1. circuit of synchronous rectification that is used for a power converter is characterized in that comprising:
One transformer, have an elementary winding and a level winding, the described secondary winding of wherein said transformer comprises a first terminal and one second terminal, wherein when switching described transformer, between described second terminal of the described secondary winding of described transformer and described the first terminal, produce one and switch voltage;
Its described second terminal from the described secondary winding of described transformer of one satiable inductor device is couple to one the 3rd terminal;
One the first transistor, its described the first terminal from the described secondary winding of described transformer is couple to an earth terminal;
One transistor seconds, it is couple to described earth terminal from described the 3rd terminal;
One inductor, it is couple to a lead-out terminal of described power converter from described the 3rd terminal;
One current sensing device, it responds an induced current of described inductor and produces a current signal;
One control circuit, it is in order to receive described switched voltage and described current signal, be respectively applied for one first control signal and one second control signal that drives described the first transistor and described transistor seconds with generation, wherein said the first transistor responds described switched voltage and is switched on, and described transistor seconds responds described current signal and is cut off; And
A diode, it is connected to described the 3rd terminal from described control circuit, detecting the voltage of described transistor seconds between described the 3rd terminal and described earth terminal,
Wherein said satiable inductor device provides a time of delay, and with when described switched voltage produces, supression one flows to the electric current of described transistor seconds from described transformer;
Wherein after described switched voltage was higher than one first thresholding, described first control signal promptly was activated; When described switched voltage is lower than one second thresholding, described first control signal is promptly disabled; When the described voltage of described transistor seconds between described the 3rd terminal and described earth terminal is lower than one the 4th thresholding, described second control signal promptly is activated; When described current signal is lower than one the 5th thresholding or described switched voltage is higher than described second thresholding, described second control signal is promptly disabled.
2. the circuit of synchronous rectification that is used for a power converter according to claim 1 is characterized in that wherein said control circuit comprises:
One first comparator, it has a positive input terminal is couple to the described secondary winding of described transformer via described first thresholding described second terminal, and a negative input end of described first comparator is couple to the described the first terminal of the described secondary winding of described transformer;
One second comparator, it has a positive input terminal is couple to the described secondary winding of described transformer via described second thresholding described second terminal, and a negative input end of described second comparator is couple to the described the first terminal of the described secondary winding of described transformer;
One the 3rd comparator, it has a positive input terminal and is couple to the described the first terminal of the described secondary winding of described transformer via one the 3rd thresholding, and a negative input end of described the 3rd comparator is couple to described second terminal of the described secondary winding of described transformer;
One the 4th comparator, it has a positive input terminal and is couple to described the 4th thresholding, and a negative input end of described the 4th comparator is couple to described the 3rd terminal, and wherein a current source is couple to the described negative input end of described the 4th comparator;
One the 5th comparator, it has a positive input terminal and is couple to described the 5th thresholding, and a negative input end of described the 5th comparator receives described current signal;
One first trigger produces described first control signal, and wherein said first comparator is enabled described first control signal, and described second comparator is forbidden described first control signal; And
One second trigger produces described second control signal, and wherein said second control signal is enabled by described the 3rd comparator and described the 4th comparator, and described second control signal is forbidden by described second comparator or described the 5th comparator.
3. the circuit of synchronous rectification that is used for a power converter according to claim 1, it is characterized in that wherein said control circuit more comprises a circuit, be used to guarantee before described first control signal is enabled, make described second control signal forbidding, and be used to guarantee before described second control signal is enabled, make described first control signal forbidding.
4. synchronous rectifier circuit that is used for a power converter is characterized in that comprising:
One the first transistor, its first terminal from a level winding of a transformer is couple to an earth terminal;
One transistor seconds, it is couple to described earth terminal from one the 3rd terminal;
One satiable inductor device, its one second terminal with the described secondary winding of described transformer is connected to described the 3rd terminal; Wherein when switching described transformer, produce one at the described secondary winding two ends of described transformer and switch voltage;
One inductor, it is couple to a lead-out terminal of described power converter from described the 3rd terminal;
One current sensing device, it responds one of described inductor and switches electric current and produce a current signal;
One control circuit, it is respectively applied for one first control signal and one second control signal that drives described the first transistor and described transistor seconds in order to receive described switched voltage and described current signal with generation; And
A diode, it is connected to described the 3rd terminal from described control circuit, to detect the voltage of described transistor seconds between described the 3rd terminal and described earth terminal;
Wherein after described switched voltage was higher than one first thresholding, described first control signal promptly was activated; When described switched voltage is lower than one second thresholding, described first control signal is promptly disabled; When the described voltage of described transistor seconds between described the 3rd terminal and described earth terminal is lower than one the 4th thresholding, described second control signal promptly is activated; When described current signal is lower than one the 5th thresholding or described switched voltage is higher than described second thresholding, described second control signal is promptly disabled.
5. the synchronous rectifier circuit that is used for a power converter according to claim 4, it is characterized in that wherein said satiable inductor device provides a time of delay, with when described switched voltage produces, supression one flows to the electric current of described transistor seconds from the described secondary winding of described transformer.
6. the synchronous rectifier circuit that is used for a power converter according to claim 4 is characterized in that wherein said control circuit comprises:
One first comparator, it has a positive input terminal is couple to the described secondary winding of described transformer via described first thresholding described second terminal, and a negative input end of described first comparator is couple to the described the first terminal of the described secondary winding of described transformer;
One second comparator, it has a positive input terminal is couple to the described secondary winding of described transformer via described second thresholding described second terminal, and a negative input end of described second comparator is couple to the described the first terminal of the described secondary winding of described transformer;
One the 3rd comparator, it has a positive input terminal and is couple to the described the first terminal of the described secondary winding of described transformer via one the 3rd thresholding, and the described negative input end of described the 3rd comparator is couple to described second terminal of the described secondary winding of described transformer;
One the 4th comparator, it has a positive input terminal and is couple to described the 4th thresholding, and a negative input end of described the 4th comparator is couple to described transistor seconds, and wherein a current source is couple to the described negative input end of described the 4th comparator;
One the 5th comparator, it has a positive input terminal and is couple to described the 5th thresholding, and a negative input end of described the 5th comparator receives described current signal;
One first trigger produces described first control signal, and wherein said first comparator is enabled described first control signal, and described second comparator is forbidden described first control signal; And
One second trigger produces described second control signal, and wherein said second control signal is enabled by described the 3rd comparator and described the 4th comparator, and described second control signal is forbidden by described second comparator or described the 5th comparator.
7. the synchronous rectifier circuit that is used for a power converter according to claim 4, it is characterized in that wherein said control circuit more comprises a circuit, be used to guarantee before described first control signal is enabled, make described second control signal forbidding, and be used to guarantee before described second control signal is enabled, make described first control signal forbidding.
8. circuit of synchronous rectification that is used for a power converter is characterized in that comprising:
One first switch, its first terminal from a level winding of a transformer is couple to an earth terminal;
One second switch, it is couple to described earth terminal from one the 3rd terminal;
One satiable inductor device, its one second terminal with the described secondary winding of described transformer is connected to described the 3rd terminal; Wherein when switching described transformer, will produce one at described secondary winding two ends and switch voltage;
One inductor, it is couple to a lead-out terminal of described power converter from described the 3rd terminal;
One current sensing device, it responds one of described inductor and switches electric current and produce a current signal;
One control circuit, it receives described switched voltage and described current signal, is respectively applied for one first control signal and one second control signal that drives described first switch and described second switch with generation; And
A diode, it is connected to described the 3rd terminal from described control circuit, to detect the voltage of described second switch between described the 3rd terminal and described earth terminal;
Wherein after described switched voltage was higher than one first thresholding, described first control signal promptly was activated; When described switched voltage is lower than one second thresholding, described first control signal is promptly disabled; When the described voltage of described second switch between described the 3rd terminal and described earth terminal is lower than one the 4th thresholding, described second control signal promptly is activated; When described current signal is lower than one the 5th thresholding or described switched voltage is higher than described second thresholding, described second control signal is promptly disabled.
9. the circuit of synchronous rectification that is used for a power converter according to claim 8 is characterized in that the wherein said satiable inductor device supression one described secondary winding from described transformer flows to an instantaneous electric current of described second switch.
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| CNB200610001513XA CN100547897C (en) | 2006-01-18 | 2006-01-18 | The control circuit that is used for the synchronous rectifier of forward power transducer |
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| CNB200610001513XA CN100547897C (en) | 2006-01-18 | 2006-01-18 | The control circuit that is used for the synchronous rectifier of forward power transducer |
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| CN100547897C true CN100547897C (en) | 2009-10-07 |
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Families Citing this family (10)
| Publication number | Priority date | Publication date | Assignee | Title |
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| US8072787B2 (en) * | 2007-10-26 | 2011-12-06 | System General Corporation | Synchronous rectifying for soft switching power converters |
| US7796407B2 (en) * | 2007-12-03 | 2010-09-14 | System General Corp. | Method and apparatus of providing synchronous regulation for offline power converter |
| US7800923B2 (en) * | 2008-02-29 | 2010-09-21 | System General Corp. | Offline synchronous switching regulator |
| CN101997438B (en) * | 2009-08-27 | 2014-07-23 | 台达电子工业股份有限公司 | Compensating device for synchronous rectification control and method thereof |
| CN101783594B (en) * | 2010-02-26 | 2012-05-23 | 东南大学 | Isolated high-light load efficiency low-output voltage high-current switch power source |
| CN102684506B (en) * | 2012-05-09 | 2014-12-24 | 广州金升阳科技有限公司 | Method for improving working efficiency of self-excited push-pull converter and self-excited push-pull converter |
| CN104242417A (en) * | 2013-06-09 | 2014-12-24 | 英华达（上海）科技有限公司 | Wireless charging rectification device and rectification circuit thereof |
| US9236809B2 (en) * | 2013-10-16 | 2016-01-12 | Texas Instruments Incorporated | Automatic timing adjustment for synchronous rectifier circuit |
| US10554138B2 (en) | 2016-10-25 | 2020-02-04 | Infineon Technologies Austria Ag | Flux limited fast transient response in isolated DC-DC converters |
| US10439500B2 (en) | 2017-02-01 | 2019-10-08 | Infineon Technologies Austria Ag | Control of isolated power converters during transient load conditions |
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