CN103259391A - Load driving circuit, power converter and controller - Google Patents
Load driving circuit, power converter and controller Download PDFInfo
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- CN103259391A CN103259391A CN2012100443833A CN201210044383A CN103259391A CN 103259391 A CN103259391 A CN 103259391A CN 2012100443833 A CN2012100443833 A CN 2012100443833A CN 201210044383 A CN201210044383 A CN 201210044383A CN 103259391 A CN103259391 A CN 103259391A
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Abstract
The invention provides a load driving circuit, a power converter and a controller. The load driving circuit comprises a transformer and the controller. The transformer is provided with a primary winding and a secondary winding and works in multiple cycles. One cycle includes a charging stage and a discharging stage. In the charging stage, input voltage supplies power for the transformer, and current flowing through the primary winding increases. In the discharging stage, the transformer discharges power to supply the power for a load, and the current flowing through the secondary winding decreases. The controller is connected with the transformer. The controller comprises a port. The port is used for receiving a first feedback signal representing the input voltage in the charging stage, receiving a second feedback signal representing the electrical energy conditions of the secondary winding in the discharging stage, and respectively generating a first control signal and a second control signal according to the first feedback signal and the second feedback signal so as to adjust the input voltage and the current flowing through the load. The load driving circuit enables the number of the ports to be reduced and reduces cost.
Description
Technical field
The present invention relates to a kind of drive circuit, particularly relate to a kind of controller that drives circuit, the power supply changeover device of load and be controlled to be the transformer of load power supply.
Background technology
Flyback converter is a kind of switching power supply, can be applied to AC/DC adapter or battery charger.Figure 1 shows that a kind of traditional flyback converter 100.This flyback converter 100 utilizes transformer of controller 120 controls.This transformer comprises and direct current source V
BBThe elementary winding 104, the secondary winding 106 that links to each other with load 112 and the auxiliary winding 108 that link to each other.When switch 118 is connected, the electric current elementary winding 104 of flowing through, magnetic core 124 energy storage of transformer.When switch 118 disconnections, diode 110 forward bias that link to each other with secondary winding, energy stored is released into electric capacity 122 and load 112 by secondary winding 106 in the magnetic core 124.To flow through electric current and reference current of current monitoring resistance 111 of error amplifier 114 compares and produces feedback signal FB.Feedback signal FB is sent to controller 120 by optical coupler 116.Controller 120 is according to the output energy of feedback signal FB control switch 118 with the adjustment transformer.The shortcoming of this tradition flyback converter 100 is that its size is relatively large.
Summary of the invention
The technical problem to be solved in the present invention is to provide a kind of drive circuit, controller and is controlled to be the controller of the transformer of load power supply, to save the area of chip and circuit board, reduces cost.
For solving the problems of the technologies described above, the invention provides a kind of circuit that drives load, it comprises transformer and the controller that is connected with described transformer at least.Described transformer, comprise the elementary winding that receives input voltage and the secondary winding that is connected in load, described transformer works in a plurality of cycles, wherein, one-period in described a plurality of cycle comprises charging stage and discharge regime, in the described charging stage, described transformer is powered by described input voltage, and the electric current of the described elementary winding of flowing through increases; At described discharge regime, described transformer discharges to give described load power supply, and the electric current that flows through described secondary winding reduces.Described controller comprises port, and wherein, in the described charging stage, described port receives first feedback signal of the described input voltage of indication; At described discharge regime, described port receives second feedback signal of the energy state of the described secondary winding of indication; Described controller produces first control signal according to described first feedback signal, to regulate described input voltage; Described controller produces second control signal according to described second feedback signal, with the flow through electric current of described load of adjusting.
The present invention also provides a kind of power supply changeover device, and described power supply changeover device comprises transformer, pair of series and is connected in the resistance of assisting on the winding, and controller.Described transformer, comprise the elementary winding that receives input voltage, the secondary winding that is connected in load, and auxiliary winding, described transformer works in a plurality of cycles, wherein, the one-period in described a plurality of cycles comprises charging stage and discharge regime, in the described charging stage, described transformer is powered by described input voltage, and flows through the electric current increase of described elementary winding; At described discharge regime, described transformer discharges to give described load power supply, and the electric current that flows through described secondary winding reduces; Described controller comprises port, and described port is connected in the common node between the described a pair of resistance, in the described charging stage, described controller with the voltage clamper on the described common node in the predeterminated voltage value.
The present invention also provides a kind of controller, is used for being controlled to be the transformer of load power supply, and described controller comprises first port, second port and the 3rd port at least.Described first port produces first control signal, to regulate the input voltage of described transformer; Described second port, produce second control signal, with the flow through electric current of described load of adjusting, and control makes described transformer work in a plurality of cycles, wherein, the one-period in described a plurality of cycles comprises charging stage and discharge regime, in the described charging stage, described transformer is powered by described input voltage, and the electric current of the described elementary winding of flowing through increases; At described discharge regime, described transformer discharges to give described load power supply, and the electric current of the described secondary winding of flowing through reduces; Described the 3rd port, be connected in the auxiliary winding of described transformer, in the described charging stage, described the 3rd port receives first feedback signal of the described input voltage of indication, at described discharge regime, described the 3rd port receives second feedback signal of the energy state of the described secondary winding of indication, wherein, described controller produces described first control signal according to described first feedback signal, produces described second control signal according to described second feedback signal.
The circuit of driving load provided by the invention, power supply changeover device and be controlled to be the controller of the transformer of load power supply, because single-port obtains different feedback signals in the different stages, therefore reduce the quantity of director port, and reduced the cost of drive circuit.
Description of drawings
Below by to the description of some embodiments of the present invention in conjunction with its accompanying drawing, can further understand purpose of the present invention, specific structural features and advantage.
Figure 1 shows that a kind of block diagram of traditional flyback converter;
Figure 2 shows that the block diagram of power supply changeover device according to an embodiment of the invention;
Figure 3 shows that the structural representation of the controller among Fig. 2;
Figure 4 shows that the oscillogram of power supply changeover device signal that receive or that produce according to an embodiment of the invention;
Figure 5 shows that the method flow diagram of controlling transformer in the power supply changeover device according to an embodiment of the invention;
Figure 6 shows that the block diagram of the drive circuit that drives load according to an embodiment of the invention;
The oscillogram of the signal that Figure 7 shows that drive circuit reception according to an embodiment of the invention or produce;
Figure 8 shows that the structural representation of controller according to an embodiment of the invention;
Figure 9 shows that the operation principle flow chart of the drive circuit that drives load according to an embodiment of the invention.
Embodiment
Below will provide detailed explanation to embodiments of the invention.Although the present invention sets forth by these execution modes and illustrates, it should be noted that the present invention not merely is confined to these execution modes.On the contrary, all substitutes, variant and the equivalent in the defined invention spirit of appended claim and the invention scope contained in the present invention.
In addition, for better explanation the present invention, provided numerous details in the embodiment hereinafter.It will be understood by those skilled in the art that does not have these details, and the present invention can implement equally.In the other example, method, flow process, element and the circuit known for everybody are not described in detail, so that highlight purport of the present invention.
The invention provides a kind of drive circuit that drives load.This drive circuit comprises transformer and controller.Transformer is operated in a plurality of cycles, and wherein at least one cycle comprises charging stage and discharge regime.In the described charging stage, transformer is powered by input voltage, and the electric current of the primary of flowing through winding increases.At described discharge regime, transformer discharges with powering load, and the electric current of the transformer secondary output winding of flowing through reduces.Advantageously, described controller comprises a port that is connected in the auxiliary winding of transformer.This port obtains indication in first feedback signal and second feedback signal of indication at the energy state of described discharge regime secondary winding of described charging stage input voltage.Therefore, controller is regulated the electric current of input voltage and the load of flowing through.Because single-port obtains different feedback signals in the different stages, so the quantity of director port reduced, and reduced the cost of drive circuit.
Figure 2 shows that the block diagram of power supply changeover device 200 according to an embodiment of the invention.Figure 4 shows that the oscillogram of power supply changeover device signal 200 receptions or that produce.Fig. 2 will be described in conjunction with Fig. 4.
In the example of Fig. 2, power supply changeover device 200 comprises transformer 202 and is used for the controller 220 of control transformer 202.In one embodiment, transformer 202 comprises elementary winding 204, secondary winding 206 and auxiliary winding 208.Elementary winding 204 1 ends and DC input voitage V
BBLink to each other, the other end is connected to ground by switch 218 and resistance 230.Secondary winding 206 is connected to load 212 by diode 210.In one embodiment, auxiliary winding 208 is positioned at elementary winding 204 1 sides of transformer 202.Auxiliary winding 208 1 ends are connected to ground by resistance 214 and resistance 216, and an other end is connected to ground.
The switch 218 that controller 220 is connected with elementary winding 204 by control comes control transformer 202.In one embodiment, controller 220 is by the voltage V of auxiliary winding 208 generations
DD Power supply.Resistance 230 provides feedback signal FB1.This feedback signal FB1 indicates the electric current I of the elementary winding 204 of flowing through
PR Auxiliary winding 208 provides feedback signal FB2.The output voltage of winding 208 is assisted in this feedback signal FB2 indication, thereby further indicates the output voltage of secondary winding 206.Therefore, feedback signal FB2 can indicate the electric current I of the secondary winding 206 of flowing through
SEWhether drop to default current value, such as whether dropping to 0.In one embodiment, the node place of feedback signal FB2 between resistance 214 and resistance 216 produces.
Particularly, at charging stage T
ON, controller 220 is connected switch 218, thereby makes transformer 202 receive input voltage V
BBWhen switch 218 is connected, diode 210 reverse bias that link to each other with secondary winding 206 do not have the electric current secondary winding 206 of flowing through.Electric current I
PRFlow through elementary winding 204, switch 218 and resistance 230 to ground.Electric current I
PRThe linear increase.Therefore, at charging stage T
ON, magnetic core 224 energy storage of transformer 202, the voltage of 228 couples of feedback signal FB2 of clamp circuit carries out clamper, makes that the voltage of feedback signal FB2 is 0.
At discharge regime T
DIS, controller 220 stopcocks 218 are powered to load 212 by transformer 202 discharges.When switch 218 disconnections, diode 210 forward bias that link to each other with secondary winding 206, magnetic core 224 releases energy to electric capacity 222 and load 212 by secondary winding 206.At discharge regime T
DIS, the electric current I of the secondary winding 206 of flowing through
SEFrom a lowest high-current value I
SE-MAXLinearity is decreased to a default current value (such as being reduced to 0).The lowest high-current value I of secondary winding 206
SE-MAXLowest high-current value I by elementary winding 204
PEAKDetermine with the elementary winding 204 of transformer 202 and the turn ratio of secondary winding 206.
At adjusting stage T
ADJ, switch 218 keeps turn-offing, and does not have electric current flow through elementary winding 204 and secondary winding 206.
Electric current I as the secondary winding 206 of flowing through among Fig. 4
SEWaveform shown in, at one-period T
SThe average current I of middle secondary winding 206 outputs
OAVGCan be obtained by equation (1).
Wherein, T
S=T
ON+ T
DIS+ T
ADJ
Charging stage T
ONTime span and discharge regime T
DISTime span can be by the inductance of elementary winding 204 and secondary winding 206, input voltage with V
BBAnd the output voltage V at load 212 two ends
OUTDetermine.Controller 220 makes adjusting stage T
ADJThereby have appropriate time span and make discharge regime T
DISTime span and period T
SThe ratio of time span be constant.Wherein, period T
STime span be charging stage T
ON, discharge regime T
DISAnd adjusting stage T
ADJTotal time span.In equation (1), the lowest high-current value I of secondary winding 206
SE-MAXLowest high-current value I by elementary winding 204
PEAKDetermine with the turn ratio of transformer 202.In one embodiment, the lowest high-current value I of elementary winding 204
PEAKBe constant with the turn ratio of transformer 202, thus the lowest high-current value I of secondary winding 206
SE-MAXIt also is constant.According to equation (1), if discharge regime T
DISTime span and period T
SThe ratio of time span be that constant (is T
S=k*T
DIS, k is constant), the average current I of secondary winding 206 output then
OAVGIt also is constant.
Therefore, even if input voltage V
BBAnd output voltage V
OUTMay change, as long as discharge regime T
DISTime span and period T
SThe ratio of time span be constant, the average current I of secondary winding 206 outputs then
OAVGIt also is constant.In other words, by a filter (as the electric capacity 222 that links to each other with load 212), power supply changeover device 200 can provide direct current for load 212.
Figure 3 shows that the structural representation of the controller 220 among Fig. 2.Fig. 3 will be described in conjunction with Fig. 2 and Fig. 4.Controller 220 makes adjusting stage T
ADJThereby have appropriate time span and make discharge regime T
DISTime span and period T
SThe ratio of time span be constant.Therefore, power supply changeover device 200 can provide direct current for load 212.
In one embodiment, controller 220 comprises oscillator 226, comparator 314, comparator 316 and pulse signal producer, such as pulse-width signal generator 318.Oscillator 226 produces sawtooth signal SAW according to feedback signal FB2.The output voltage of feedback signal FB2 indication secondary winding 206.Comparator 314 compares sawtooth signal SAW and reference signal SET.Reference signal SET has reference voltage level V
SETComparator 316 compares feedback signal FB1 and reference signal PEAK.Feedback signal FB1 indicates the electric current I of the elementary winding 204 of flowing through
SEReference signal PEAK determine the to flow through lowest high-current value I of elementary winding 204
PEAKPulse-width signal generator 318 links to each other with comparator 314 and comparator 316, and produces a pulse-width signal PWM1.The duty ratio of the sawtooth signal control pulse-width signal PWM1 that oscillator 226 produces.Thereby the output energy of the conducting state control transformer 202 of pulse-width signal PWM1 control switch 318.
If the voltage of electric capacity 310 rises to reference voltage level V
SET, then controller 220 produce pulse-width signal PWM1 with first level (such as, PWM1 is logical one) to connect switch 218.Thereby make transformer 202 work in charging stage T
ONClamp circuit 228 makes that the voltage of feedback signal FB2 is 0, thereby control signal CTRL has first level (as logical zero).Switch 308 in the control signal CTRL control generator 226.Control signal CTRL is connected to switch 306 by not gate 312.In the example of Fig. 3, when control signal CTRL was logical zero, switch 306 was connected, and switch 308 disconnects.Electric capacity 310 is by the current charges of current source 302.Therefore, the voltage of electric capacity 310 (also being the voltage of sawtooth signal SAW) is from reference voltage level V
SETBegin to rise.Simultaneously, the flow through electric current I of elementary winding 204
PR Increase.Comparator 316 compares feedback signal FB1 and reference signal PEAK.When the voltage of feedback signal FB1 reaches the voltage of reference signal PEAK, the electric current I of the elementary winding 204 of flowing through is described
PRIncrease to lowest high-current value I
PEAK, this moment controller 220 cut-off switch 218, thereby complete charge stage T
ONAnd startup discharge regime T
DISParticularly, pulse-width signal generator 318 produce pulse-width signal PWM1 with second level (such as, PWM1 is logical zero) with cut-off switch 218.As charging stage T
ONDuring end, the voltage of electric capacity 310 (also being the voltage of sawtooth signal SAW) rises to the first magnitude of voltage V
1, as shown in Figure 4.In other words, the voltage of electric capacity 310 (also being the voltage of sawtooth signal SAW) is from reference voltage level V
SETRise to the first magnitude of voltage V
1Interior switch 218 is connected during this period of time.
At discharge regime T
DIS, switch 218 disconnects the electric current I of the secondary winding 206 of flowing through
SEFrom lowest high-current value I
SE-MAXReduce.At discharge regime T
DIS, auxiliary winding 208 produces VD.This output voltage is by resistance 214 and 216 dividing potential drops.At discharge regime T
DIS, the voltage of feedback signal FB2 (being the voltage at resistance 216 two ends) is directly proportional with the output voltage of auxiliary winding 208, and therefore, feedback signal FB2 also is a direct voltage.In one embodiment, suitably select the resistance of resistance 214 and resistance 216, make at discharge regime T
DIS, the voltage of feedback signal FB2 is greater than predetermined threshold value TH.When the voltage of feedback signal FB2 greater than predetermined threshold value TH, control signal CTRL is logical one, switch 306 is disconnected and switch 308 is connected.Electric capacity 310 is with the current discharge of current source 304, and the voltage of electric capacity 310 is from the first magnitude of voltage V
1Descend.
When the voltage of feedback signal FB2 drops to threshold T H, the electric current I of the secondary winding 206 of also namely flowing through
SEWhen being reduced to default current value, controller 220 finishes discharge regime T
DISAnd startup adjusting stage T
ADJIn one embodiment, when the electric current I of the secondary winding 206 of flowing through
SEBe reduced to 0 o'clock, controller 220 finishes discharge regime T
DISAnd startup adjusting stage T
ADJAs discharge regime T
DISDuring end, the voltage of electric capacity 310 (also being the voltage of sawtooth signal SAW) drops to the second magnitude of voltage V
2, as shown in Figure 4.
At adjusting stage T
ADJ, because the voltage of feedback signal FB2 drops to threshold T H, control signal CTRL becomes logical zero.Switch 306 is connected, and switch 308 disconnects.Electric capacity 310 is again by the current charges of current source 302.The voltage of electric capacity 310 is from the second magnitude of voltage V
2Rise.At adjusting stage T
ADJ, switch 218 remains open, and does not have electric current flow through elementary winding 204 or secondary winding 206.When the voltage of sawtooth signal SAW rises to reference voltage level V
SET, then controller 220 finishes adjusting stage T
ADJAnd connect switch 218 to start next cycle T
SIn charging stage T
ONSpecifically, pulse-width signal generator 318 produce pulse-width signal PWM1 with first level (such as, PWM1 is logical one) to connect switch 218.
The capacitance of supposing electric capacity 310 is C
1, the electric current of current source 302 is I
1, the electric current of current source 304 is I
2At charging stage T
ONDuring end, the voltage of sawtooth signal SAW (voltage of electric capacity 310) can be expressed as:
At discharge regime T
DISDuring end, the voltage of sawtooth signal SAW can be expressed as:
At adjusting stage T
ADJDuring end, the voltage of sawtooth signal SAW can be expressed as:
Therefore, adjusting stage T
ADJTime span can be released by equation (2)-(4), that is:
By equation (5), adjusting stage T
ADJTime span and period T
STime span between relation can be expressed as:
Can obtain discharge regime T according to equation (6)
DISTime span and charging stage T
ON, discharge regime T
DISAnd adjusting stage T
ADJThe ratio of total time span by electric current I
1, I
2Determine.If electric current I
1, I
2Constant magnitude, discharge regime T then
DISTime span and period T
STime span proportional.Therefore, with reference to equation (1), the average output current I of secondary winding 206
OAVGBe constant.
Figure 5 shows that the method flow diagram 500 of controlling transformer in the power supply changeover device according to an embodiment of the invention.Fig. 5 will be described in conjunction with Fig. 2, Fig. 3 and Fig. 4.
In step 502, control transformer 202 works in a plurality of cycles.One-period comprises charging stage T
ON, discharge regime T
DISWith adjusting stage T
ADJ
In step 504, at charging stage T
ON, to transformer 202 power supplies.At charging stage T
ON, the switch 218 of connecting with the elementary winding 204 of transformer 202 is connected.In one embodiment, control charging stage T by monitoring stream through the electric current of elementary winding 204
ONTime span.When the electric current of the elementary winding 204 of flowing through increases to a default lowest high-current value, complete charge stage T
ONAnd startup discharge regime T
DISWhen the charging stage finishes, cut-off switch 218.
In step 506, at discharge regime T
DIS, utilize 202 pairs of load power supplies of transformer.In one embodiment, control discharge regime T by the output voltage of monitoring transformer 202 auxiliary windings 208
DISTime span.The output voltage of auxiliary winding 208 can indicate the electric current of transformer 202 secondary winding 206 of flowing through whether to drop to a default current value.Particularly, when the electric current of the secondary winding 206 of flowing through is reduced to default current value (as being reduced to 0), finish discharge regime T
DISAnd startup adjusting stage T
ADJIn one embodiment, when the output voltage of auxiliary winding 208 was decreased to a default magnitude of voltage, the electric current of the secondary winding 206 of flowing through was decreased to default current value.
In step 508, determine adjusting stage T
ADJTime span, make discharge regime T
DISTime span and charging stage T
ON, discharge regime T
DISAnd adjusting stage T
ADJTotal time span between ratio be constant.In one embodiment, adjusting stage T
ADJTime span determined by oscillator 226.Oscillator 226 produces sawtooth signal SAW.At charging stage T
ON, the voltage of sawtooth signal SAW is from default reference voltage level V
SETRise to the first magnitude of voltage V
1At discharge regime T
DIS, the voltage of sawtooth signal SAW is from the first magnitude of voltage V
1Drop to the second magnitude of voltage V
2At adjusting stage T
ADJ, the voltage of sawtooth signal SAW is from the second magnitude of voltage V
2Rise to default reference voltage level V
SETWhen the voltage of sawtooth signal SAW rises to default reference voltage level V
SETThe time, finish adjusting stage T
ADJAnd start a new period T
S
In sum, the method that the invention provides a kind of power supply changeover device and power supply changeover device is controlled.Power supply changeover device comprises the transformer that works in a plurality of cycles.At least one cycle comprises charging stage T
ON, discharge regime T
DISWith adjusting stage T
ADJPower supply changeover device can be so that adjusting stage T
ADJHave suitable time span, thereby make discharge regime T
DISTime span and period T
SThe ratio of time span be constant.Period T
STime span be charging stage T
ON, discharge regime T
DISWith adjusting stage T
ADJTotal time span.Therefore, in one-period, the mean value of the electric current of transformer output is constant.
Power supply changeover device provided by the invention can be applied to multiple occasion.Such as, this power supply changeover device can provide direct current to export to drive light sources such as light-emitting diode, also can provide direct current output with to battery charge.
Compare with the traditional flyback converter that comprises optical coupler and error amplifier, the size of power supply changeover device provided by the invention is less relatively.
In addition, even if the variation of the input voltage of power supply changeover device and output voltage may cause charging stage T
ONWith discharge regime T
DISTime span change, this power supply changeover device can be regulated adjusting stage T automatically
ADJTime span to keep discharge regime T
DISTime span and period T
SThe ratio of time span be constant.Therefore, this power supply changeover device can be regulated automatically and export the constant electric current of mean value.And can see that from equation (1) mean value of the output current of this power supply changeover device is not subjected to the influence of Transformer Winding inductance value, thereby can control output current more accurately.
Figure 6 shows that the block diagram of the drive circuit 600 of driving load 212 according to an embodiment of the invention.Number identical assembly with Fig. 2 among Fig. 6 and have similar function.In the example of Fig. 6, drive circuit 600 links to each other with power supply 602, and power supply 602 produces AC-input voltage V
AC, for example: V
ACBe to have sine-shaped alternating voltage.Drive circuit 600 receives AC-input voltage V as a power supply changeover device
ACAnd provide output voltage V
OUTBe load 212 power supplies.Load 212 can be but be not limited to light source (for example, LED source).
In one embodiment, drive circuit 600 comprises rectifier 603, transducer 604, transformer 202 and controller 620.In one embodiment, controller 620 comprises port VDD, port DRV1, port CS1, port DRV2, port CS2 and port FB.Rectifier 603 rectification AC-input voltage V
AC, so that commutating voltage V to be provided
REC(for example, have after the rectification sinusoidal waveform).Electric capacity 605 is as filter, with level and smooth commutating voltage V
RECTransducer 604 is connected between rectifier 603 and the transformer 202, with commutating voltage V
RECConvert input voltage V to
INIn the embodiment of Fig. 6, transducer 604 is boost converter, comprises inductance L 1, diode D1, capacitor C 1, resistance R 1 and switch 613.Yet the present invention is not limited thereto, and transducer 604 also can be other types, for example step-down controller or buck-boost transducer.Resistance R 1 provides the monitor signal 656 of the electric current of indicating the inductance L 1 of flowing through, and controller 620 receives monitor signal 656 by port CS1.Transformer 202 is by input voltage V
INPower supply, and produce output voltage V
OUTBe load 212 power supplies.Be connected in the electric capacity 222 of load 212, with the flow through electric current I of load 212 of filtering
LOADRipple.Controller 620 produces switch controlling signal 654 at port DRV1, to regulate input voltage V
IN, and produce switch controlling signal 650 at port DRV2, with the flow through electric current I of load 212 of adjusting
LOAD
In one embodiment, transformer 202 comprises elementary winding 204, secondary winding 206, auxiliary winding 208 and magnetic core 224.One end of elementary winding 204 links to each other with transducer 604, and the other end is connected to ground by switch 218 and resistance 230.Secondary winding 206 is connected to load 212 by diode 210 and electric capacity 222.In one embodiment, an end of auxiliary winding 208 is connected to ground by resistance 614 and resistance 616, and the other end is connected to ground.The port FB of controller 620 is connected to the common node of resistance 614 and resistance 616.
Figure 7 shows that the oscillogram of the signal that drive circuit 600 according to an embodiment of the invention receives or produces.Fig. 7 will be described in conjunction with Fig. 6.Waveform shown in Figure 7 represent successively the to flow through electric current I of elementary winding 204
PR, the secondary winding 206 of flowing through electric current I
SE, auxiliary winding 208 the voltage V of non-same polarity
AUX, the controller 620 of flowing through the electric current I of port FB
FB, port FB place voltage V
FBWith switch controlling signal 650.
In one embodiment, controller 620 produces switch controlling signal 650, with conducting or cut-off switch 218, makes transformer 202 work in a plurality of cycles.In one embodiment, one-period comprises charging stage T
ONWith discharge regime T
DISPerhaps, embodiment as shown in Figure 7, one-period comprise charging stage T
ON, discharge regime T
DISWith adjusting stage T
ADJIn both cases, switch controlling signal 650 all is at charging stage T
ONActuating switch 218, and at discharge regime T
DISCut-off switch 218.Therefore, at charging stage T
ON, transformer 202 is by input voltage V
INPower supply, the electric current I of the elementary winding 204 of flowing through
PRIncrease.In one embodiment, at charging stage T
ON, resistance 230 produces indicator current I
PRMonitor signal 652.The port CS2 of controller 620 receives monitor signal 652.At discharge regime T
DIS, transformer 202 discharges are powered the electric current I of the secondary winding 206 of flowing through to give load 212
SEReduce.
At charging stage T
ONWith discharge regime T
DIS, transformer 202 provides different feedback signals for the port FB of controller 620.Particularly, in one embodiment, at charging stage T
ON, voltage V
AUXMagnitude of voltage V
3Voltage V with elementary winding 204
INProportional, can be obtained by equation (7):
V
AUX＝V
3＝-V
IN*(N
A/N
P)(7)
Wherein, N
AThe number of turn of the auxiliary winding 208 of expression, N
PThe number of turn of representing elementary winding 204.Shown in equation (7), voltage V
AUXAt charging stage T
ONBe negative magnitude of voltage.In one embodiment, controller 620 is with the voltage V of port FB
FBClamper is predeterminated voltage value (for example, 0 volt), to prevent voltage V
FBDrop to below 0 volt.Therefore, in one embodiment, at charging stage T
ON, voltage V
FBEqual 0 volt.So, electric current I
FBFlow to auxiliary winding 208 from the port FB resistance 614 of flowing through.Electric current I
FBCurrent value I
3Can be obtained by equation (8):
I
FB＝I
3＝V
IN*(N
A/N
P)/R
614(8)
Wherein, R
614The resistance of expression resistance 614.Because (N
A/ N
P)/R
614Be a substantially invariable constant, electric current I
FBCurrent value I
3With voltage V
INProportional.
At discharge regime T
DIS, the energy state of auxiliary winding 208 inductive secondary windings 206.Particularly, in one embodiment, when the electric current I of the secondary winding 206 of flowing through
SEReduce the voltage V on the auxiliary winding 208
AUXHas positive magnitude of voltage V
4(for example, V
4=V
OUT* (N
A/ N
S)), N wherein
SThe number of turn of expression secondary winding 206.Work as electric current I
SEWhen being reduced to predetermined current value (for example, 0 ampere), voltage V
AUXProduce trailing edge.616 couples of voltage V of resistance 614 and resistance
AUXCarry out dividing potential drop, to provide and voltage V
AUXProportional voltage V
FBTherefore, at discharge regime T
DIS, the voltage V of port FB
FBIndicate the electric current I of the secondary winding 206 of flowing through
SEWhether be reduced to the predetermined current value.
Therefore, at charging stage T
ON, the electric current I of the port FB that flows through
FBWith input voltage V
INProportional.At discharge regime T
DIS, the voltage V of port FB
FBIndicator current I
SEWhether be reduced to the predetermined current value.Advantageously, controller 620 receives indication input voltage V by same port FB
INThe first feedback signal I
FBThe second feedback signal V with the energy state of indicating secondary winding 206
FBTherefore, reduce the port number of controller 620, thereby reduced size and the cost of drive circuit 600.
In one embodiment, controller 620 is according to the switch controlling signal 654 of the first feedback signal control port DRV1, with regulation voltage V
IN(for example, with voltage V
INBe adjusted to target voltage values).In addition, controller 620 is according to the switch controlling signal 650 of the second feedback signal control port DRV2, to regulate electric current I
LOAD(for example, with electric current I
LOADRemain on constant current value).The operation principle of controller 620 will further describe in Fig. 8.
In one embodiment, electric capacity 605 has less appearance value (for example, less than 0.5 microfarad), to help to eliminate or reduce commutating voltage V
RECWave distortion (to proofread and correct the power factor of drive circuit 600).Make input voltage V by the transducer 604 that is connected between rectifier 603 and the transformer 202
INHas substantially invariable magnitude of voltage.Because voltage V
INRelatively stable, thus electric current I reduced
LOADRipple.
Figure 8 shows that the structural representation of controller 620 according to an embodiment of the invention.There is the assembly of same numeral to have similar function among Fig. 8 and Fig. 2, Fig. 3 and Fig. 6.Fig. 8 will be described in conjunction with Fig. 3, Fig. 4, Fig. 6 and Fig. 7.As shown in Figure 8, controller 620 comprises voltage control unit 802 and current control unit 804.Voltage control unit 802 monitoring streams are through the electric current I of port FB
FB, and at port DRV1 generation switch controlling signal 654, to regulate input voltage V
INVoltage V on the current control unit 804 monitoring port FB
FB, and at port DRV2 generation switch controlling signal 650, to regulate output current I
OUT
In one embodiment, current control unit 804 has the structure similar to Fig. 3 middle controller 220.Current control unit 804 comprises control signal generator 320, oscillator 226, comparator 314, comparator 316 and pulse-width signal generator 318.Control signal generator 320 is according to the second feedback signal V
FBProduce control signal CTRL.Oscillator 226 receives control signal CTRL, and produces sawtooth signal SAW thus.Comparator 314 compares sawtooth signal SAW and reference signal SET.Comparator 316 will be indicated charging stage T
ONElectric current I
PRMonitor signal 652 and reference signal PEAK1 compare.Reference signal PEAK1 determine the to flow through peak current I of elementary winding 204
PEAK1Pulse width modulating signal generator 318 links to each other with comparator 316 with comparator 314, and produces switch controlling signal 650 (for example, pulse width modulating signal), with control switch 218.
Similar with the operation principle of controller 220, the duty ratio of sawtooth signal SAW control pulse-width signal 650.Particularly, in conjunction with as described in Fig. 3 and Fig. 4, at charging stage T
ON, sawtooth signal SAW is from the magnitude of voltage V of reference signal SET
SETBeginning increases, at this moment, and the electric current I of the elementary winding 204 of flowing through
PRIncrease.Voltage indicator current I when monitor signal 652
PRReach peak current I
PEAK1The time (for example, when sawtooth signal SAW reaches magnitude of voltage VI), switch controlling signal 650 cut-off switch 218 are with complete charge stage T
ONAnd startup discharge regime T
DISAt discharge regime T
DIS, the electric current I of the secondary winding 206 of flowing through
SEReduce, sawtooth signal SAW begins to descend from magnitude of voltage V1.Work as electric current I
SE(work as voltage V when being reduced to predetermined current value (for example, 0 ampere)
FBWhen producing a trailing edge), sawtooth signal SAW drops to magnitude of voltage V2.Thus, current control unit 804 finishes discharge regime T
DISAnd startup adjusting stage T
ADJAt adjusting stage T
ADJ, sawtooth signal SAW begins to rise from magnitude of voltage V2.When sawtooth signal SAW rises to magnitude of voltage V
SETThe time, current control unit 804 actuating switchs 218, thus begin a new cycle.
Advantageously, according to equation (6), current control unit 804 makes discharge regime T
DISTime span and charging stage T
ON, discharge regime T
DISAnd adjusting stage T
ADJTotal time span between ratio keep constant substantially, therefore, the electric current I of the load 212 of flowing through
LOADBasic maintenance is constant.Current control unit 804 can have other structure and be not limited to embodiment shown in Figure 8.
In one embodiment, voltage control unit 802 comprises clamp circuit 810, current detector 808 and voltage regulator 818.Described in conjunction with Fig. 6, when switch 218 closures, the voltage V of auxiliary winding 208
AUXBe negative value.Clamp circuit 810 is connected with port FB, the voltage V of detection port FB
FB, and at charging stage T
ONWith voltage V
FBClamper is predeterminated voltage value (for example, 0 volt), to prevent voltage V
FBDrop to below 0 volt.Thus, electric current I
FBFlow to port FB from current detector 808 clamp circuit 810 of flowing through.
In one embodiment, current detector 808 comprises current mirror 812, resistance 814 and sampling hold circuit 816.Current mirror 812 image current I
FB, to produce and electric current I
FBEquate or proportional electric current I
MElectric current I
MThe resistance 814 of flowing through, therefore, the voltage V on the resistance 814
MAlso with electric current I
FBProportional.According to equation (8), at charging stage T
ON, electric current I
FBWith input voltage V
INProportional.So, voltage V
MWith input voltage V
INProportional.Sampling hold circuit 816 is at charging stage T
ONTo voltage V
MSample, and remain on charging stage T
ONVoltage V
MSampled value produce to keep voltage V
HTherefore, at discharge regime T
DISWith adjusting stage T
ADJAlthough, electric current I
FBDrop to 0 ampere, keep voltage V
HStill indicate input voltage V
INValue.
For instance, voltage regulator 818 comprises error amplifier 820, comparator 822, comparator 823 or door 828, oscillator 824 and pulse-width signal generator 826.Oscillator 824 produces sawtooth signal V
SAWWith clock signal 850 (for example, pulse signal).An input of error amplifier 820 receives indication input voltage V
INThe reference signal V of desired value
REF, another input receives and keeps voltage V
HError amplifier 820 amplifies maintenance voltage V
HWith reference signal V
REFDifference, produce to amplify voltage V
AMPComparator 822 is sawtooth voltage V relatively
SAWWith amplification voltage V
AMP, produce comparative voltage V
C1Comparator 823 is with the flow through electric current I of inductance L 1 of indication
INDMonitor signal 656 and indicator current I
INDThe reference signal V of peak value
PEAKCompare, to produce comparative voltage V
C2Or door 852 receives comparative voltage V
C1With comparative voltage V
C2, and produce control signal 852 thus.
Pulse-width signal generator 826 produces switch controlling signal 654 according to clock signal 850 and control signal 852, with control switch 613, thereby regulates input voltage V
INIn one embodiment, pulse-width signal generator 826 is according to clock signal 850 actuating switchs 613, according to control signal 852 cut-off switch 613.Particularly, in one embodiment, clock signal 850 is the substantially invariable pulse signals of frequency.Therefore, the ON time of switch 613 and turn-off time also are substantially invariable.In addition, indication input voltage V
INMaintenance voltage V
HDetermined the ON time of switch 613.Therefore, the duty ratio of switch controlling signal 654 is by keeping voltage V
HDetermine.For example, if keep voltage V
HGreater than reference voltage V
REF, then show input voltage V
IN(this target voltage values is by reference voltage V greater than target voltage values
REFIndication), the duty ratio of switch controlling signal 654 reduces, to reduce input voltage V
INOtherwise, when keeping voltage V
HLess than reference voltage V
REF, then show input voltage V
INLess than target voltage values, the duty ratio of switch controlling signal 654 increases, to increase input voltage V
INTherefore, with input voltage V
INAdjust to target voltage values.
In one embodiment, the flow through electric current I of inductance L 1 of transducer 604
INDFunction with overcurrent protection.For example, if monitor signal 656 greater than reference voltage V
PEAK, then show electric current I
INDGreater than peak current, switch controlling signal 654 cut-off switch 613.Voltage control unit 802 can have other structure, is not limited to embodiment shown in Figure 8.
Figure 9 shows that the operational flowchart of the drive circuit (for example, driving the drive circuit 600 of load 212) of driving load according to an embodiment of the invention.Fig. 9 will be described in conjunction with Fig. 6-Fig. 8.Though Fig. 9 has disclosed concrete step, these steps are only done exemplary type explanation, and the present invention is equally applicable to other steps or some conversion steps of step as described in Figure 9.
In step 902, transformer (for example, transformer 202) works in a plurality of cycles.In one embodiment, one-period comprises charging stage and discharge regime.In another embodiment, one-period comprises charging stage, discharge regime and adjusting stage.In step 904, in the charging stage, transformer is powered by input voltage, and the electric current of the primary of flowing through winding increases.In step 906, at discharge regime, transformer discharges with powering load, and the electric current of the transformer secondary output winding of flowing through reduces.
In step 908, in the charging stage, the voltage clamper of the director port (for example, port FB) that will be connected with the auxiliary winding of transformer is at predeterminated voltage value (for example, 0 volt).
In step 910, in the charging stage, port FB receives first feedback signal of indication input voltage.In one embodiment, first feedback signal comprises electric current (for example, the flow through electric current I of port FB of the port FB that flows through
FB).In step 912, port FB receives second feedback signal of indication secondary winding energy state.In one embodiment, second feedback signal comprises voltage (for example, the voltage V of port FB of port FB
FB).
Above embodiment and accompanying drawing only are embodiment commonly used of the present invention.Obviously, under the prerequisite that does not break away from the present invention's spirit that claims define and invention scope, can have and variously augment, revise and replace.It should be appreciated by those skilled in the art that the present invention can change aspect form, structure, layout, ratio, material, element, assembly and other to some extent according to concrete environment and job requirement in actual applications under the prerequisite that does not deviate from the invention criterion.Therefore, embodiment disclosed here only is illustrative rather than definitive thereof, and scope of the present invention is defined by claims and legal equivalents thereof, and the description before being not limited thereto.
Claims (27)
1. a circuit that drives load is characterized in that, the circuit of described driving load comprises at least:
Transformer, described transformer comprises the elementary winding that receives input voltage and the secondary winding that is connected in load, described transformer works in a plurality of cycles, and wherein, the one-period in described a plurality of cycles comprises charging stage and discharge regime, in the described charging stage, described transformer is powered by described input voltage, and the increase of the electric current of the described elementary winding of flowing through, at described discharge regime, described transformer discharges to give described load power supply, and the electric current that flows through described secondary winding reduces; And
With the controller that described transformer is connected, described controller comprises port, and wherein, in the described charging stage, described port receives first feedback signal of the described input voltage of indication; At described discharge regime, described port receives second feedback signal of the described secondary winding energy state of indication; Described controller produces first control signal according to described first feedback signal, to regulate described input voltage; Described controller produces second control signal according to described second feedback signal, with the flow through electric current of described load of adjusting.
2. the circuit of driving load according to claim 1 is characterized in that, the circuit of described driving load also comprises:
Be connected the transducer between power supply and the described elementary winding, described transducer converts the input ac voltage that described power supply produces to described input voltage, and regulates described input voltage according to described first control signal.
3. the circuit of driving load according to claim 1 is characterized in that, wherein, described transformer also comprises:
Be connected in the auxiliary winding of described port, in the described charging stage, the described input voltage on the voltage on the described auxiliary winding and the described elementary winding is proportional.
4. the circuit of driving load according to claim 3 is characterized in that, the circuit of described driving load also comprises:
Be connected in the resistance between the described port of described auxiliary winding and described controller, in the described charging stage, in the predeterminated voltage value, and in the described charging stage, the current value of the described resistance of flowing through and described input voltage are proportional with the voltage clamper of described port for described controller.
5. the circuit of driving load according to claim 1, it is characterized in that wherein, described transformer also comprises the auxiliary winding that is connected in described port, at described discharge regime, whether the electric current that described secondary winding is flow through in the indication of the voltage of described auxiliary winding drops to preset value.
6. the circuit of driving load according to claim 1 is characterized in that, wherein, described first feedback signal comprises the electric current of the described port of flowing through, and described second feedback signal comprises the voltage on the described port.
7. the circuit of driving load according to claim 1 is characterized in that, wherein, described controller also comprises:
Be connected in the current mirror of described port, for the electric current of the described port of flowing through at the charging stage mirror image, so that the electric current of the resistance of flowing through to be provided; And
Be connected in the sampling hold circuit of described current mirror, be used for sampling and keep described ohmically voltage, to produce the inhibit signal of the described input voltage of indication.
8. the circuit of driving load according to claim 1, it is characterized in that, wherein, described one-period also comprises the adjusting stage, described second control signal makes the time span of described discharge regime and the ratio between total time span of described charging stage, described discharge regime and described adjusting stage keep constant, with the flow through described electric current of described load of adjustment.
9. the circuit of driving load according to claim 8 is characterized in that, wherein, described controller also comprises:
Current control unit, when described second feedback signal indicated the described electric current of the described secondary winding of flowing through to drop to the predetermined current value, described current control unit finished described discharge regime and starts the described adjusting stage.
10. the circuit of driving load according to claim 8 is characterized in that, wherein, described controller also comprises:
Signal generator, for generation of sawtooth signal, wherein, in the described charging stage, described sawtooth signal rises to first magnitude of voltage from the preset reference magnitude of voltage; At described discharge regime, described sawtooth signal drops to second magnitude of voltage from described first magnitude of voltage; In the described adjusting stage, described sawtooth signal rises to described preset reference magnitude of voltage from described second magnitude of voltage.
11. the circuit of driving load according to claim 10 is characterized in that, the circuit of described driving load also comprises:
With the switch of described elementary windings in series, wherein, rise to the process of described first magnitude of voltage described switch of described controller conducting from described preset reference magnitude of voltage in described sawtooth signal; When the electric current of the described elementary winding of flowing through increased to the pre-set peak value electric current, described controller disconnected described switch.
12. the circuit of driving load according to claim 8 is characterized in that, the circuit of described driving load also comprises:
With the switch of described elementary windings in series, wherein, described controller disconnects described switch at the described switch of described charging stage conducting at described discharge regime and described adjusting stage.
13. a power supply changeover device is characterized in that, described power supply changeover device comprises at least:
Transformer, described transformer comprises the elementary winding that receives input voltage, the secondary winding that is connected in load, and auxiliary winding, described transformer works in a plurality of cycles, wherein, the one-period in described a plurality of cycles comprises charging stage and discharge regime, in the described charging stage, described transformer is powered by described input voltage, and flows through the electric current increase of described elementary winding; At described discharge regime, described transformer discharges to give described load power supply, and the electric current that flows through described secondary winding reduces;
The resistance of a pair of mutual series connection, and described a pair of resistance is connected in described auxiliary winding; And
Controller, described controller comprises port, described port is connected in the common node between the described a pair of resistance, in the described charging stage, described controller with the voltage clamper on the described common node in the predeterminated voltage value.
14. power supply changeover device according to claim 13 is characterized in that, wherein, in the described charging stage, described electric current and the described input voltage of the described port of flowing through are proportional; At described discharge regime, the voltage of described port indicates the electric current of the described secondary winding of flowing through whether to drop to preset value.
15. power supply changeover device according to claim 14 is characterized in that, wherein, at described discharge regime, described resistance is with the voltage dividing potential drop on the described auxiliary winding, so that described branch pressure voltage is offered described port.
16. power supply changeover device according to claim 14, it is characterized in that, wherein, described a pair of resistance comprises first resistance that is connected in described auxiliary winding and is connected in second resistance of the node with reference voltage, and the described electric current of the described port of flowing through also flow through described secondary winding and described first resistance.
17. power supply changeover device according to claim 14 is characterized in that, wherein, described controller also comprises:
Be connected in the current detector of described port, in the described charging stage, the flow through described electric current of described port of described current detector mirror image is to provide the electric current of the 3rd resistance of flowing through, described current detector keeps the described the 3rd ohmically voltage that inhibit signal is provided by sampling
Described controller produces control signal based on described inhibit signal, to regulate described input voltage.
18. power supply changeover device according to claim 13, it is characterized in that, wherein, described one-period also comprises the adjusting stage, described controller makes the time span of described discharge regime and the ratio between total time span of described charging stage, described discharge regime and described adjusting stage keep constant, with the flow through described electric current of described load of adjustment.
19. power supply changeover device according to claim 18 is characterized in that, wherein, described controller also comprises:
Signal generator, for generation of sawtooth signal, wherein, in the described charging stage, described sawtooth signal rises to first magnitude of voltage from the preset reference magnitude of voltage; At described discharge regime, described sawtooth signal drops to second magnitude of voltage from described first magnitude of voltage; In the described adjusting stage, described sawtooth signal rises to described preset reference magnitude of voltage from described second magnitude of voltage.
20. power supply changeover device according to claim 19 is characterized in that, described power supply changeover device also comprises:
Switch with described elementary windings in series, wherein, rise to the process of described first magnitude of voltage from described preset reference magnitude of voltage in described sawtooth signal, the described switch of described controller conducting, when the described electric current of the described elementary winding of flowing through was increased to the pre-set peak value electric current, described controller disconnected described switch.
21. power supply changeover device according to claim 18 is characterized in that, described power supply changeover device also comprises:
With the switch of described elementary windings in series, wherein, in the described charging stage, the described switch of described controller conducting; In described discharge regime and described adjusting stage, described controller disconnects described switch.
22. a controller is used for being controlled to be the transformer that load is powered, and it is characterized in that described controller comprises at least:
First port, described first port produces first control signal, to regulate the input voltage of described transformer;
Second port, described second port produces second control signal, with the flow through electric current of described load of adjusting, and make described transformer work in a plurality of cycles, wherein, the one-period in described a plurality of cycles comprises charging stage and discharge regime, in the described charging stage, described transformer is powered by described input voltage, and the electric current of the described elementary winding of flowing through increases; At described discharge regime, described transformer discharges to give described load power supply, and the electric current of the described secondary winding of flowing through reduces; And
The 3rd port, described the 3rd port is connected in the auxiliary winding of described transformer, and in the described charging stage, described the 3rd port receives first feedback signal of the described input voltage of indication; At described discharge regime, described the 3rd port receives second feedback signal of the energy state of the described secondary winding of indication,
Wherein, described controller produces described first control signal according to described first feedback signal, produces described second control signal according to described second feedback signal.
23. controller according to claim 22 is characterized in that, described controller also comprises:
Be connected in the current mirror of described the 3rd port, in the described charging stage, the flow through electric current of described the 3rd port of described current mirror mirror image is to provide the electric current of the resistance of flowing through; And
Be connected in the sampling hold circuit of described current mirror, described sampling hold circuit sampling also keeps described ohmically voltage, to produce the inhibit signal of the described input voltage of indication.
24. controller according to claim 22 is characterized in that, wherein, described first feedback signal comprises the electric current of described the 3rd port of flowing through, and described second feedback signal comprises the voltage on described the 3rd port.
25. controller according to claim 22, it is characterized in that, wherein, described one-period also comprises the adjusting stage, described controller makes the time span of described discharge regime and the ratio between total time span of described charging stage, described discharge regime and described adjusting stage keep constant, with the flow through described electric current of described load of adjustment.
26. controller according to claim 25 is characterized in that, described controller also comprises:
Signal generator, for generation of sawtooth signal, wherein, in the described charging stage, described sawtooth signal rises to first magnitude of voltage from the preset reference magnitude of voltage; At described discharge regime, described sawtooth signal drops to second magnitude of voltage from described first magnitude of voltage; In the described adjusting stage, described sawtooth signal rises to described preset reference magnitude of voltage from described second magnitude of voltage.
27. controller according to claim 22 is characterized in that, described controller also comprises:
Clamp circuit, in the described charging stage, described clamp circuit with the voltage clamper on described the 3rd port in the predeterminated voltage value.
Priority Applications (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2012100443833A CN103259391A (en) | 2012-02-21 | 2012-02-21 | Load driving circuit, power converter and controller |
| US13/443,786 US8811045B2 (en) | 2009-12-25 | 2012-04-10 | Circuits and methods for controlling power converters including transformers |
| TW101141638A TWI505611B (en) | 2012-02-21 | 2012-11-08 | Controller, power converter for controlling transformer, and load driving circuit thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2012100443833A CN103259391A (en) | 2012-02-21 | 2012-02-21 | Load driving circuit, power converter and controller |
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| Publication Number | Publication Date |
|---|---|
| CN103259391A true CN103259391A (en) | 2013-08-21 |
Family
ID=48963146
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2012100443833A Pending CN103259391A (en) | 2009-12-25 | 2012-02-21 | Load driving circuit, power converter and controller |
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| Country | Link |
|---|---|
| CN (1) | CN103259391A (en) |
| TW (1) | TWI505611B (en) |
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| CN104300952A (en) * | 2014-11-03 | 2015-01-21 | 西安电子科技大学 | Self-adaptive drive circuit for environment-friendly switching mode power supply chip |
| CN104660046A (en) * | 2013-11-19 | 2015-05-27 | 台湾类比科技股份有限公司 | Constant current control circuit of power converter and constant current control method thereof |
| CN117134605A (en) * | 2023-04-28 | 2023-11-28 | 荣耀终端有限公司 | Power supply circuit, power supply control method, and power supply device |
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| TW201525641A (en) * | 2013-12-16 | 2015-07-01 | jing-yue Xu | Ultra high voltage regulator |
| KR102084801B1 (en) * | 2014-03-10 | 2020-03-05 | 매그나칩 반도체 유한회사 | Switch control circuit, switch control method and converter using the same |
| TWI578682B (en) * | 2015-09-11 | 2017-04-11 | 通嘉科技股份有限公司 | Sample-and-hold circuit for generating a variable sample signal of a power converter and method thereof |
| TWI683597B (en) * | 2019-02-13 | 2020-01-21 | 宏碁股份有限公司 | Voltage compensation driving circuit |
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Also Published As
| Publication number | Publication date |
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| TWI505611B (en) | 2015-10-21 |
| TW201336213A (en) | 2013-09-01 |
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Application publication date: 20130821 |