CN202268802U - Switch conversion circuit and integrated circuit used therein - Google Patents
Switch conversion circuit and integrated circuit used therein Download PDFInfo
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- CN202268802U CN202268802U CN2011203595843U CN201120359584U CN202268802U CN 202268802 U CN202268802 U CN 202268802U CN 2011203595843 U CN2011203595843 U CN 2011203595843U CN 201120359584 U CN201120359584 U CN 201120359584U CN 202268802 U CN202268802 U CN 202268802U
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Abstract
A switching converter circuit and an integrated circuit for the switching converter circuit are disclosed. The switching conversion circuit includes: the first end of the first switch tube is electrically coupled to the input end of the switch conversion circuit; the first end of the second switching tube is electrically coupled to the second end of the first switching tube, and the switch conversion circuit transmits power to the load through the first switching tube and the second switching tube in a second working state; a third switch tube, the first end of which is electrically coupled to the second end of the first switch tube and the first end of the second switch tube; the control circuit is electrically coupled to the gate electrodes of the second switching tube and the third switching tube and controls the conduction and the disconnection of the second switching tube and the third switching tube; and a first end of the first capacitor is electrically coupled to the other end of the third switching tube and the control circuit to provide power supply voltage for the control circuit, a second end of the first capacitor is grounded, and the switching conversion circuit charges the first capacitor through the first switching tube and the third switching tube in a first working state.
Description
Technical field
The embodiment of the utility model relates to a kind of switching circuit, especially, relates to a kind of switch transformed circuit, and the integrated circuit that is used for this switch transformed circuit.
Background technology
Switch transformed circuit converts input signal into the output signal through the conducting of switching tube with shutoff.Usually, conducting and shutoff that switch transformed circuit adopts control circuit (being generally integrated circuit) to come the control switch pipe, this control circuit needs DC-voltage supply.When switch transformed circuit just started, the supply power voltage of control circuit needed a period of time to set up, and is called as start-up time during this period of time.In this start-up time, switch transformed circuit can't operate as normal.
In most of application scenarios, need shorten the start-up time of switch transformed circuit as much as possible.Especially for the led drive circuit of controllable silicon light modulation (triac dimming) and since when minimum light modulation phase place the time of reverse-blocking tetrode thyristor pipe conducting very short, can directly limit the degree of depth of LED light modulation the start-up time of switch transformed circuit.
Fig. 1 is a kind of circuit diagram of existing switch transformed circuit.Rectifier bridge is with input voltage V
InConvert into and do not control direct voltage, comprise transformer T1, switching tube M, diode D
OutWith capacitor C
OutCircuit of reversed excitation be electrically coupled to the output of rectifier bridge, will not control direct voltage and convert the output signal into to drive load.Conducting and the shutoff of control circuit 101 control switch pipe M.One end of resistor R 1 is electrically coupled to the output of rectifier bridge, and the other end is electrically coupled to capacitor C1.The voltage at capacitor C1 two ends is as the supply power voltage of control circuit 101.Switch transformed circuit the startup stage, input voltage V
InBe capacitor C1 charging through rectifier bridge and resistor R 1.Be enough to make control circuit 201 operate as normal when the voltage at capacitor C1 two ends increases to, after promptly switch transformed circuit gets into normal work stage, the auxiliary winding of transformer T1 will be control circuit 101 power supplies through diode D1.In this supply power mode, if will reduce start-up time, need to increase the charging current of capacitor C1, this can realize through resistance that reduces resistor R 1 or the appearance value that reduces capacitor C1.Yet the resistance that reduces resistor R 1 can increase the power that this resistor consumes, and causes the efficient reduction of switch converters and the temperature of resistor R 1 to raise.And capacitor C1 is being owing to bearing the responsibility of stabilization control circuit supply power voltage, and its appearance value can not be fallen too smallly.
Fig. 2 is the circuit diagram of another kind of existing switch transformed circuit.Control circuit 201 comprises high-tension current source I1 and switching tube S.High-tension current source I1 is electrically coupled to the output of rectifier bridge, switch transformed circuit the startup stage be capacitor C1 charging through switching tube S.After switch transformed circuit got into normal work stage, switching tube S was turned off, and high-tension current source I1 breaks off from capacitor C1, and the auxiliary winding of transformer T1 is control circuit 201 power supplies through diode D1.Switch transformed circuit short, high efficiency start-up time shown in Figure 2, but switching tube S wherein need bear high pressure, and the cost of injectron is high and be not easy to integrated.
The utility model content
The utility model provides a kind of integrated circuit that is different from the switch transformed circuit of prior art and is used for this switch transformed circuit.
A kind of switch transformed circuit according to the utility model one embodiment comprises: first switching tube, have first end, second end and gate pole, and wherein first end is electrically coupled to the input of switch transformed circuit; The second switch pipe has first end, second end and gate pole, and wherein first end is electrically coupled to second end of first switching tube, switch transformed circuit under second operating state through first switching tube and second switch pipe to load transfer power; The 3rd switching tube has first end, second end and gate pole, and wherein first end is electrically coupled to second end of first switching tube and first end of second switch pipe; Control circuit is electrically coupled to the gate pole of second switch pipe and the 3rd switching tube, the conducting and the shutoff of control second switch pipe and the 3rd switching tube; And first capacitor; Have first end and second end; Wherein first end is electrically coupled to the other end and the control circuit of the 3rd switching tube; For control circuit provides supply power voltage, the second end ground connection, switch transformed circuit is first capacitor charging through first switching tube and the 3rd switching tube under first operating state.
In one embodiment, this switch transformed circuit also comprises the auxiliary power supply circuit, and the output that the input electric coupling of this auxiliary power supply circuit or magnetic are coupled to switch transformed circuit, output are electrically coupled to first end of first capacitor.
In one embodiment, control circuit compares supply power voltage and the first threshold that first capacitor provides, and when supply power voltage increases to greater than first threshold, turn-offs the 3rd switching tube.
In one embodiment, control circuit compares the supply power voltage and second threshold value that first capacitor provides, when supply power voltage is decreased to less than second threshold value, and conducting the 3rd switching tube, wherein second threshold value is less than first threshold.
In one embodiment, this switch transformed circuit also comprises second diode, and the anode of this second diode is electrically coupled to second end of first switching tube and first end of second switch pipe, and cathodic electricity is coupled to first end of the 3rd switching tube.
In one embodiment, this switch transformed circuit also comprises the 3rd diode, and the anode of the 3rd diode is electrically coupled to second end of first switching tube and first end of second switch pipe, and cathodic electricity is coupled to the gate pole of first switching tube.
In one embodiment, this switch transformed circuit also comprises drive circuit, and the input of this drive circuit is electrically coupled to the input of switch transformed circuit, and output is electrically coupled to the gate pole of first switching tube.
In one embodiment, this drive circuit comprises: resistor, have first end and second end, and wherein first end is electrically coupled to the input of switch transformed circuit; And second capacitor, have first end and second end, wherein first end is electrically coupled to second end of resistor and the gate pole of first switching tube, the second end ground connection.
A kind of switch transformed circuit according to the utility model one embodiment comprises: transformer comprises elementary winding, secondary winding and auxiliary winding; First switching tube, its drain electrode are electrically connected to the elementary winding of transformer; The second switch pipe, its drain electrode is electrically connected to the source electrode of first switching tube, source ground; The 3rd switching tube has first end, second end and gate pole, and wherein first end is electrically coupled to the drain electrode of the source electrode and the second switch pipe of first switching tube; Control circuit is electrically coupled to the grid of second switch pipe and the gate pole of the 3rd switching tube, the conducting and the shutoff of control second switch pipe and the 3rd switching tube; First capacitor has first end and second end, and wherein first end is electrically connected to second end and the control circuit of the 3rd switching tube, for control circuit provides supply power voltage, and the second end ground connection; First diode, its anode are electrically coupled to the auxiliary winding of transformer, and cathodic electricity is connected to first end of first capacitor; Resistor has first end and second end, and wherein first end is electrically coupled to the input of switch transformed circuit; And second capacitor, have first end and second end, wherein first end is electrically connected to second end of resistor and the grid of first switching tube, the second end ground connection.
In one embodiment, this switch transformed circuit also comprises second diode, and the anode of this second diode is electrically connected to the drain electrode of the source electrode and the second switch pipe of first switching tube, and cathodic electricity is connected to first end of the 3rd switching tube.
In one embodiment, this switch transformed circuit also comprises the 3rd diode, and the anode of the 3rd diode is electrically connected to the drain electrode of the source electrode and the second switch pipe of first switching tube, and cathodic electricity is connected to the grid of first switching tube.
In one embodiment, control circuit compares supply power voltage and the first threshold that first capacitor provides, and when supply power voltage increases to greater than first threshold, turn-offs the 3rd switching tube.
In one embodiment, control circuit compares the supply power voltage and second threshold value that first capacitor provides, when supply power voltage is decreased to less than second threshold value, and conducting the 3rd switching tube, wherein second threshold value is less than first threshold.
A kind of integrated circuit that is used for switch transformed circuit according to the utility model one embodiment; This switch transformed circuit comprises: the transformer that comprises elementary winding, secondary winding and auxiliary winding; Drain electrode is electrically connected to first switching tube of primary winding, and for integrated circuit provides first capacitor of supply power voltage, this integrated circuit comprises: the second switch pipe; Its drain electrode is electrically connected to the source electrode of first switching tube, source ground; The 3rd switching tube has first end, second end and gate pole, and wherein first end is electrically coupled to the drain electrode of the source electrode and the second switch pipe of first switching tube, and second end is electrically connected to first capacitor; And control circuit, be electrically coupled to the grid of second switch pipe and the gate pole of the 3rd switching tube, the conducting and the shutoff of control second switch pipe and the 3rd switching tube.
In one embodiment, switch transformed circuit also comprises: first diode, its anode are electrically coupled to the auxiliary winding of transformer, and cathodic electricity is connected to first end of first capacitor; Resistor has first end and second end, and wherein first end is electrically coupled to the input of switch transformed circuit; And second capacitor, have first end and second end, wherein first end is electrically connected to second end of resistor and the grid of first switching tube.
In one embodiment, this integrated circuit also comprises second diode, and the anode of this second diode is electrically connected to the drain electrode of the source electrode and the second switch pipe of first switching tube, and cathodic electricity is connected to first end of the 3rd switching tube.
In one embodiment; Control circuit compares supply power voltage and first threshold, second threshold value that first capacitor provides; When supply power voltage increases to greater than first threshold, turn-off the 3rd switching tube, when supply power voltage is decreased to less than second threshold value; Conducting the 3rd switching tube, wherein second threshold value is less than first threshold.
Description of drawings
Fig. 1 is a kind of circuit diagram of existing switch transformed circuit;
Fig. 2 is the circuit diagram of another kind of existing switch transformed circuit;
Fig. 3 is the block diagram according to the switch transformed circuit of the utility model one embodiment;
Fig. 4 is the circuit diagram according to the switch transformed circuit of the utility model one embodiment;
Fig. 5 is the oscillogram according to the switch transformed circuit shown in Figure 4 of the utility model one embodiment.
Embodiment
To describe the specific embodiment of the utility model below in detail, should be noted that the embodiments described herein only is used to illustrate, be not limited to the utility model.In the following description, for the thorough to the utility model is provided, a large amount of specific detail have been set forth.Yet it is obvious that for those of ordinary skills: needn't adopt these specific detail to carry out the utility model.In other instances,, do not specifically describe known circuit, material or method for fear of obscuring the utility model.
In whole specification, " embodiment ", " embodiment ", " example " or mentioning of " example " are meaned: the special characteristic, structure or the characteristic that combine this embodiment or example to describe are comprised among at least one embodiment of the utility model.Therefore, phrase " in one embodiment ", " in an embodiment ", " example " or " example " that occurs in each place of whole specification differs to establish a capital and refers to same embodiment or example.In addition, can make up specific characteristic, structure or property combination in one or more embodiment or example with any suitable combination and/or son.In addition, it should be understood by one skilled in the art that at this accompanying drawing that provides all be for illustrative purposes, and accompanying drawing is not necessarily to draw in proportion.Should be appreciated that when claiming that element " is connected to " or during " being couple to " another element it can be directly to connect or be couple to another element or can have intermediary element.On the contrary, when claiming that element " is directly connected to " or during " directly being couple to " another element, not having intermediary element.Identical Reference numeral indication components identical.Term used herein " and/or " comprise any and all combinations of one or more relevant projects of listing.
Fig. 3 is the block diagram according to the switch transformed circuit 300 of the utility model one embodiment, comprises switching tube S1～S3, control circuit 301 and capacitor C1.Switching tube S1 has first end, second end and gate pole, and wherein first end is electrically coupled to the input of switch transformed circuit 300.Switching tube S2 has first end, second end and gate pole, and wherein first end is electrically coupled to second end of switching tube S1.Switching tube S3 has first end, second end and gate pole, and wherein first end is electrically coupled to second end of switching tube S1 and first end of switching tube S2.Control circuit 301 is electrically coupled to the gate pole of switching tube S2 and switching tube S3, conducting and the shutoff of control switch pipe S2 and switching tube S3.Capacitor C1 has first end and second end, and wherein first end is electrically coupled to second end and the control circuit 301 of switching tube S3, for control circuit provides supply power voltage V
CC, the second end ground connection.Switch transformed circuit 300 is capacitor C1 charging through switching tube S1 and S3 under first operating state, under second operating state through switching tube S1 and S2 to load transfer power.
Switching tube S1～S3 can be any controllable semiconductor switch device, for example mos field effect transistor (MOSFET), bipolar junction transistor (BJT), junction field effect transistor (JFET) etc.In one embodiment, switch transformed circuit 300 also comprises drive circuit 302.The input of this drive circuit 302 is electrically coupled to the input of switch transformed circuit 300, and output is electrically coupled to the gate pole of switching tube S1.
In one embodiment, switch transformed circuit 300 also comprises auxiliary power supply circuit 303.The input electric coupling of this auxiliary power supply circuit 303 or magnetic are coupled to the output of switch transformed circuit 300, and output is electrically coupled to first end of capacitor C1.In the normal work stage of switch transformed circuit 300, auxiliary power supply circuit 303 is control circuit 301 power supplies.
In one embodiment, switch transformed circuit 300 also comprises diode D2.The anode of diode D2 is electrically coupled to second end of switching tube S1 and first end of switching tube S2, and cathodic electricity is coupled to first end of switching tube S3.Diode D2 can prevent that capacitor C1 is through switching tube S3 discharge.
In one embodiment, switch transformed circuit 300 also comprises diode D3.The anode of diode D3 is electrically coupled to second end of switching tube S1 and first end of switching tube S2, and cathodic electricity is coupled to the gate pole of switching tube S1.Diode D3 carries out clamper to the voltage of switching tube S1 second end, its maximum is limited to the gate voltage of switching tube S1.
Switch transformed circuit 300 the startup stage, switching tube S3 conducting, switching tube S2 does not set up enough supply power voltages as yet and keeps turn-offing owing to control circuit 301.Switch transformed circuit 300 is in first operating state, and input signal IN is capacitor C1 charging, supply power voltage V through switching tube S1 and S3
Cc-Progressively increase.This moment, switching tube S1 worked in the saturation region, was in source electrode following state or emitter following state, its gate voltage of the voltage follow of its second end (for example being tens volts).
As supply power voltage V
CcIncreasing to is enough to make control circuit 301 operate as normal, and switch transformed circuit 300 gets into normal work stage.Switch transformed circuit 300 is in second operating state, converts input signal IN into output signal OUT to drive load through switching tube S1 and S2.Switching tube S3 turn-offs, and auxiliary power supply circuit 303 is control circuit 301 power supplies.When switching tube S2 conducting, switching tube S1 works in the variable resistor district, and its conduction resistance value is very little.When switching tube S2 turn-offed, diode D3 was limited to the maximum of the voltage of switching tube S1 second end gate voltage of switching tube S1.
In one embodiment, when auxiliary power supply circuit 303 can't provide enough energy when guaranteeing the supply power voltage of control circuit 301, switch transformed circuit 300 gets into first operating state again, is that capacitor C1 charges through switching tube S1 and S3.Above-mentioned situation possibly appear at switch transformed circuit 300 startup just and finish, when work is still unstable, when perhaps switch transformed circuit 300 turn-offs switching tube S2 because of meeting with fault.In one embodiment, switch transformed circuit 300 is for adopting the led drive circuit of controllable silicon light modulation, and in the light modulation phase place hour, above-mentioned auxiliary power supply circuit 303 can't provide enough energy also possibly occur with the situation that guarantees control circuit 301 supply power voltages.
In one embodiment, control circuit 301 is with supply power voltage V
CCWith threshold value V
Th1Compare, as supply power voltage V
CCIncrease to greater than threshold value V
Th1The time, on-off switching tube S3.In one embodiment, control circuit 301 is with supply power voltage V
CCWith threshold value V
Th2Compare, as supply power voltage V
CCBe decreased to less than threshold value V
Th2The time, actuating switch pipe S3, wherein threshold value V
Th2Less than threshold value V
Th1
Because first end of switching tube S2 and S3 is electrically coupled to second end of switching tube S1, switching tube S2 and S3 need not to bear high pressure, and promptly switching tube S2 and S3 need not to adopt injectron.The toggle speed of switch transformed circuit 300 is fast, high efficiency and with low cost.
Below be that example describes the utility model with the ac/dc translation circuit that comprises circuit of reversed excitation; But those skilled in the art can know; The utility model also can be used for any other DC circuit or AC/DC translation circuit, like BUCK-BOOST (liter-step-down) circuit, FLYBACK (anti-sharp) circuit and FORWARD (normal shock) circuit etc.
Fig. 4 is the circuit diagram according to the switch transformed circuit 400 of the utility model one embodiment.Switch transformed circuit 400 comprises rectifier bridge, transformer T1, switching tube S1～S3, resistor R 2, capacitor C1 and C2, control circuit 401, drive circuit 402, auxiliary power supply circuit 403, diode D as driven for emitting lights diode string
OutAnd output capacitor C
Out
Rectifier bridge receives AC-input voltage V
In, and convert thereof into and do not control direct voltage.Transformer T1 comprises elementary winding, secondary winding and auxiliary winding.Switching tube S1 and S2 are N type MOSFET.The drain electrode of switching tube S1 is electrically connected to the elementary winding of transformer.The drain electrode of switching tube S2 is electrically connected to the source electrode of switching tube S1, source ground.First end of switching tube S3 is electrically coupled to the drain electrode of source electrode and the switching tube S2 of switching tube S1.Control circuit 401 is electrically coupled to the grid of switching tube S2 and the gate pole of switching tube S3, produces control signal CTRL2 and CTRL3 conducting and the shutoff with control switch pipe S2 and S3.First end of capacitor C1 is electrically connected to second end and the control circuit 401 of switching tube S3, for control circuit 401 provides supply power voltage V
CC, the second end ground connection.Diode D
OutAnode be electrically connected to an end of transformer T1 secondary winding, cathodic electricity is connected to output capacitance C
OutAn end, output capacitance C
OutThe other end be electrically connected to the other end of transformer T1 secondary winding.In one embodiment, diode D
OutReplace by synchronous rectifier.
In one embodiment, switch transformed circuit 400 also comprises diode D2.The anode of diode D2 is electrically connected to the drain electrode of source electrode and the switching tube S2 of switching tube S1, and cathodic electricity is connected to first end of switching tube S3.
In one embodiment, switch transformed circuit 400 also comprises voltage stabilizing didoe D4.The cathodic electricity of this voltage stabilizing didoe D4 is connected to first end of capacitor C2, plus earth.Voltage stabilizing didoe D4 is parallelly connected with capacitor C2, to the voltage V at capacitor C2 two ends
G1Carry out clamper.
In one embodiment, switch transformed circuit 400 also comprises diode D3.The anode of diode D3 is electrically connected to the drain electrode of source electrode and the switching tube S2 of switching tube S1, and cathodic electricity is connected to the grid of switching tube S1.Diode D3 is to the drain-source voltage V of switching tube S2
Ds2Carry out clamper, its maximum is limited to the voltage V at capacitor C2 two ends
G1When switch transformed circuit 400 worked in discontinuous mode, after the energy of in switching tube S2 shutoff, transformer T1, storing all was sent to load, the parasitic capacitance of the magnetizing inductance of transformer T1 and switching tube S2 can produce resonance.This resonant energy can be recovered to capacitor C2 through diode D3, thereby improves the efficient of switch transformed circuit 400.In this case, even the output voltage of rectifier bridge is very low, the driving voltage of switching tube S1, i.e. the voltage V at capacitor C2 two ends
G1Also can be maintained.This performance is very important concerning the led drive circuit of controllable silicon light modulation.
In one embodiment, control circuit 401 also comprises hysteresis comparator COM.The in-phase input end of this hysteresis comparator COM is electrically connected to first end of capacitor C1 to receive supply power voltage V
CC, inverting input receive threshold V
Th1And V
Th2As supply power voltage V
CCIncrease to greater than or more than or equal to threshold value V
Th1The time, hysteresis comparator COM output high level is with on-off switching tube S3.As supply power voltage V
CCBe decreased to less than or smaller or equal to threshold value V
Th2The time, hysteresis comparator COM output low level is with actuating switch pipe S3.The initial value of hysteresis comparator COM output signal is a low level.
In one embodiment, switching tube S2, S3 and control circuit 401 are integrated in the integrated circuit.In one embodiment, this integrated circuit also comprises diode D2.
Fig. 5 is the waveform according to the switch transformed circuit shown in Figure 4 400 of the utility model one embodiment.At t0 constantly, switch transformed circuit 400 starts switching tube S3 conducting.This moment is because the supply power voltage V of control circuit 401
CCDo not set up as yet, switching tube S2 turn-offs.Input voltage V
InThrough rectifier bridge and 2 pairs of capacitor C2 chargings of resistor R, the voltage V at capacitor C2 two ends
G1Increase gradually.
At t1 constantly, voltage V
G1Increase to the threshold voltage V of switching tube S1
Th, switching tube S1 conducting.Input voltage V
InCapacitor C1 is charged supply power voltage V through rectifier bridge, switching tube S1, S3 and diode D2
CCIncrease gradually.This moment, switching tube S1 worked in the saturation region, was used as source follower, thereby V
CC=V
G1-V
Th
At t2 constantly, supply power voltage V
CCIncrease to threshold value V
Th1, switching tube S3 is turned off.Switching tube S2 begins conducting and shutoff under the control of control circuit 401, thereby with input voltage V
InThe output current that converts expectation into is with driven for emitting lights diode string.At this moment, supply power voltage V
CCAuxiliary winding by transformer T1 provides.
At t3 constantly, because the auxiliary winding of transformer T1 can't provide enough energy, supply power voltage V
CCBegin to reduce.This situation possibly appear at switch transformed circuit 400 and just start and finish, and when work is still unstable, also possibly appears at switch transformed circuit 400 and adopt controllable silicon light modulations, and the light modulation phase place hour.At t4 constantly, supply power voltage V
CCBe decreased to threshold value V
Th2, switching tube S3 is switched on.Input voltage V
InWhen switching tube S2 turn-offs, capacitor C1 is charged supply power voltage V through rectifier bridge, switching tube S1, S3 and diode D2
CCIncrease gradually.At t5 constantly, supply power voltage V
CCIncrease to threshold value V
Th1, switching tube S3 is turned off once more.In one embodiment, at supply power voltage V
CCTo threshold value V
Th2After, switching tube S2 is turned off, input voltage V
InThrough rectifier bridge, switching tube S1, S3 and diode D2 capacitor C1 is charged, until supply power voltage V
CCIncrease to threshold value V
Th1
Switch transformed circuit 400 may meet with various faults in the course of the work, for example overcurrent, overvoltage, overheated etc.When detecting fault, switch transformed circuit 400 often turn-offs switching tube S2 to reach the purpose of self-protection.As shown in Figure 5, at t6 constantly, switch transformed circuit 400 detects fault and switching tube S2 is turn-offed, and the auxiliary winding of transformer T1 can't be again for capacitor C1 provides energy, supply power voltage V
CCBegin to reduce.
At t7 constantly, supply power voltage V
CCBe decreased to threshold value V
Th2, switching tube S3 is switched on.Input voltage V
InCapacitor C1 is charged supply power voltage V through rectifier bridge, switching tube S1, S3 and diode D2
CCIncrease gradually.At t8 constantly, supply power voltage V
CCIncrease to threshold value V
Th1, switching tube S3 is turned off once more, and switch transformed circuit 400 attempts recovering operate as normal.In one embodiment, if above-mentioned fault state disappears in the time at t6～t8, switch transformed circuit 400 will recover operate as normal automatically.
In one embodiment, nonserviceable down, switching tube S3 is until supply power voltage V
CCBe decreased to threshold value V
Th3Shi Fang is switched on, wherein V
Th3Less than V
Th2In one embodiment, V
Th1Equal 10V, V
Th2Equal 9V, V
Th3Equal 7V.In one embodiment, nonserviceable down, as supply power voltage V
CCBe decreased to threshold value V
Th3, switching tube S3 is switched on, as supply power voltage V
CCIncrease to threshold value V
Th1, switching tube S3 is turned off, and above process repeats.Switch transformed circuit 400 is at supply power voltage V
CcThe N time (for example N=4) reaches threshold value V
Th1The time, the side attempts recovering operate as normal.
Though described the utility model with reference to several exemplary embodiments, should be appreciated that used term is explanation and exemplary and nonrestrictive term.Because the utility model practical implementation and do not break away from the spirit or the essence of utility model in a variety of forms; So be to be understood that; The foregoing description is not limited to any aforesaid details; And should in enclose spirit that claim limited and scope, explain widely, therefore fall into whole variations and remodeling in claim or its equivalent scope and all should be the claim of enclosing and contain.
Claims (17)
1. a switch transformed circuit is characterized in that, comprising:
First switching tube has first end, second end and gate pole, and wherein first end is electrically coupled to the input of switch transformed circuit;
The second switch pipe has first end, second end and gate pole, and wherein first end is electrically coupled to second end of first switching tube, switch transformed circuit under second operating state through first switching tube and second switch pipe to load transfer power;
The 3rd switching tube has first end, second end and gate pole, and wherein first end is electrically coupled to second end of first switching tube and first end of second switch pipe;
Control circuit is electrically coupled to the gate pole of second switch pipe and the 3rd switching tube, the conducting and the shutoff of control second switch pipe and the 3rd switching tube; And
First capacitor; Have first end and second end; Wherein first end is electrically coupled to the other end and the control circuit of the 3rd switching tube; For control circuit provides supply power voltage, the second end ground connection, switch transformed circuit is first capacitor charging through first switching tube and the 3rd switching tube under first operating state.
2. switch transformed circuit as claimed in claim 1 is characterized in that, also comprises the auxiliary power supply circuit, and the output that the input electric coupling of this auxiliary power supply circuit or magnetic are coupled to switch transformed circuit, output are electrically coupled to first end of first capacitor.
3. switch transformed circuit as claimed in claim 1 is characterized in that, wherein control circuit compares supply power voltage and the first threshold that first capacitor provides, and when supply power voltage increases to greater than first threshold, turn-offs the 3rd switching tube.
4. switch transformed circuit as claimed in claim 3; It is characterized in that wherein control circuit compares the supply power voltage and second threshold value that first capacitor provides, when supply power voltage is decreased to less than second threshold value; Conducting the 3rd switching tube, wherein second threshold value is less than first threshold.
5. switch transformed circuit as claimed in claim 1 is characterized in that, also comprises second diode, and the anode of this second diode is electrically coupled to second end of first switching tube and first end of second switch pipe, and cathodic electricity is coupled to first end of the 3rd switching tube.
6. switch transformed circuit as claimed in claim 1 is characterized in that, also comprises the 3rd diode, and the anode of the 3rd diode is electrically coupled to second end of first switching tube and first end of second switch pipe, and cathodic electricity is coupled to the gate pole of first switching tube.
7. switch transformed circuit as claimed in claim 1 is characterized in that, also comprises drive circuit, and the input of this drive circuit is electrically coupled to the input of switch transformed circuit, and output is electrically coupled to the gate pole of first switching tube.
8. switch transformed circuit as claimed in claim 7 is characterized in that wherein drive circuit comprises:
Resistor has first end and second end, and wherein first end is electrically coupled to the input of switch transformed circuit; And
Second capacitor has first end and second end, and wherein first end is electrically coupled to second end of resistor and the gate pole of first switching tube, the second end ground connection.
9. a switch transformed circuit is characterized in that, comprising:
Transformer comprises elementary winding, secondary winding and auxiliary winding;
First switching tube, its drain electrode are electrically connected to the elementary winding of transformer;
The second switch pipe, its drain electrode is electrically connected to the source electrode of first switching tube, source ground;
The 3rd switching tube has first end, second end and gate pole, and wherein first end is electrically coupled to the drain electrode of the source electrode and the second switch pipe of first switching tube;
Control circuit is electrically coupled to the grid of second switch pipe and the gate pole of the 3rd switching tube, the conducting and the shutoff of control second switch pipe and the 3rd switching tube;
First capacitor has first end and second end, and wherein first end is electrically connected to second end and the control circuit of the 3rd switching tube, for control circuit provides supply power voltage, and the second end ground connection;
First diode, its anode are electrically coupled to the auxiliary winding of transformer, and cathodic electricity is connected to first end of first capacitor;
Resistor has first end and second end, and wherein first end is electrically coupled to the input of switch transformed circuit; And
Second capacitor has first end and second end, and wherein first end is electrically connected to second end of resistor and the grid of first switching tube, the second end ground connection.
10. switch transformed circuit as claimed in claim 9 is characterized in that, also comprises second diode, and the anode of this second diode is electrically connected to the drain electrode of the source electrode and the second switch pipe of first switching tube, and cathodic electricity is connected to first end of the 3rd switching tube.
11. switch transformed circuit as claimed in claim 9 is characterized in that, also comprises the 3rd diode, the anode of the 3rd diode is electrically connected to the drain electrode of the source electrode and the second switch pipe of first switching tube, and cathodic electricity is connected to the grid of first switching tube.
12. switch transformed circuit as claimed in claim 9 is characterized in that, wherein control circuit compares supply power voltage and the first threshold that first capacitor provides, and when supply power voltage increases to greater than first threshold, turn-offs the 3rd switching tube.
13. switch transformed circuit as claimed in claim 12; It is characterized in that wherein control circuit compares the supply power voltage and second threshold value that first capacitor provides, when supply power voltage is decreased to less than second threshold value; Conducting the 3rd switching tube, wherein second threshold value is less than first threshold.
14. integrated circuit that is used for switch transformed circuit; It is characterized in that; This switch transformed circuit comprises: the transformer that comprises elementary winding, secondary winding and auxiliary winding; Drain electrode is electrically connected to first switching tube of primary winding, and for integrated circuit provides first capacitor of supply power voltage, this integrated circuit comprises:
The second switch pipe, its drain electrode is electrically connected to the source electrode of first switching tube, source ground;
The 3rd switching tube has first end, second end and gate pole, and wherein first end is electrically coupled to the drain electrode of the source electrode and the second switch pipe of first switching tube, and second end is electrically connected to first capacitor; And
Control circuit is electrically coupled to the grid of second switch pipe and the gate pole of the 3rd switching tube, the conducting and the shutoff of control second switch pipe and the 3rd switching tube.
15. integrated circuit as claimed in claim 14 is characterized in that, wherein switch transformed circuit also comprises:
First diode, its anode are electrically coupled to the auxiliary winding of transformer, and cathodic electricity is connected to first end of first capacitor;
Resistor has first end and second end, and wherein first end is electrically coupled to the input of switch transformed circuit; And
Second capacitor has first end and second end, and wherein first end is electrically connected to second end of resistor and the grid of first switching tube.
16. integrated circuit as claimed in claim 15 is characterized in that, also comprises second diode, the anode of this second diode is electrically connected to the drain electrode of the source electrode and the second switch pipe of first switching tube, and cathodic electricity is connected to first end of the 3rd switching tube.
17. integrated circuit as claimed in claim 14; It is characterized in that wherein control circuit compares supply power voltage and first threshold, second threshold value that first capacitor provides, when supply power voltage increases to greater than first threshold; Turn-off the 3rd switching tube; When supply power voltage is decreased to less than second threshold value, conducting the 3rd switching tube, wherein second threshold value is less than first threshold.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011203595843U CN202268802U (en) | 2011-09-23 | 2011-09-23 | Switch conversion circuit and integrated circuit used therein |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011203595843U CN202268802U (en) | 2011-09-23 | 2011-09-23 | Switch conversion circuit and integrated circuit used therein |
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| Publication Number | Publication Date |
|---|---|
| CN202268802U true CN202268802U (en) | 2012-06-06 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2011203595843U Expired - Lifetime CN202268802U (en) | 2011-09-23 | 2011-09-23 | Switch conversion circuit and integrated circuit used therein |
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| Country | Link |
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| CN (1) | CN202268802U (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102355134A (en) * | 2011-09-23 | 2012-02-15 | 成都芯源系统有限公司 | Switch conversion circuit and conversion method |
| CN103826362A (en) * | 2014-01-28 | 2014-05-28 | 杰华特微电子（杭州）有限公司 | LED drive circuit and control method thereof |
| CN104410303A (en) * | 2014-11-27 | 2015-03-11 | 成都芯源系统有限公司 | High-voltage current source and providing method thereof |
-
2011
- 2011-09-23 CN CN2011203595843U patent/CN202268802U/en not_active Expired - Lifetime
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102355134A (en) * | 2011-09-23 | 2012-02-15 | 成都芯源系统有限公司 | Switch conversion circuit and conversion method |
| CN102355134B (en) * | 2011-09-23 | 2013-09-18 | 成都芯源系统有限公司 | Switch conversion circuit and conversion method |
| CN103826362A (en) * | 2014-01-28 | 2014-05-28 | 杰华特微电子（杭州）有限公司 | LED drive circuit and control method thereof |
| CN103826362B (en) * | 2014-01-28 | 2016-03-16 | 杰华特微电子（杭州）有限公司 | A kind of LED drive circuit and control method thereof |
| CN104410303A (en) * | 2014-11-27 | 2015-03-11 | 成都芯源系统有限公司 | High-voltage current source and providing method thereof |
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