CN100423433C - Flexible starter - Google Patents
Flexible starter Download PDFInfo
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- CN100423433C CN100423433C CNB2005100082110A CN200510008211A CN100423433C CN 100423433 C CN100423433 C CN 100423433C CN B2005100082110 A CNB2005100082110 A CN B2005100082110A CN 200510008211 A CN200510008211 A CN 200510008211A CN 100423433 C CN100423433 C CN 100423433C
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- power supply
- input
- electric capacity
- signal
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Abstract
The present invention provides a flexible starter which is used for power suppliers. The present invention outputs a compensating signal to a pulse width modulation controller when the power suppliers are started. The present invention comprises a starting capacitor, a first power supply, a voltage stabilizing unit, an error amplifier, and a clamping diode, wherein the starting capacitor is charged by the first power supply; a build-in reference voltage is received by a first input terminal of the voltage stabilizing unit; the reference voltage and a feedback signal are received by the error amplifier to output the compensating signal; the clamping diode is connected to the fourth input terminal and the second output terminal; the voltage level of the compensating signal is clamped when the power suppliers are started. The pulse width of switching signals outputted by the pulse width modulation controller can be generated in an increscent state which is gradually increased from initial values to the set value, and the pulse width is adjusted according to load conditions after the pulse width modulation controller is started, so the present invention can avoid large voltage and current stress which is caused at the moment of starting of the power switch.
Description
Technical field
The present invention relates to a kind of flexible starter, refer to a kind of being used in the power supply unit especially, the flexible starter of the pulse duration that the switching signal output when power supply unit is started is cumulative.
Background technology
Various power supply units has made widely and has been used to provide the stable output voltage of adjusting.Please refer to Fig. 1, be the circuit box schematic diagram of known power source supply.The known power source supply comprises suitching type circuit 30, switching controller 10, outputting inductance L, output capacitance C
1, divider resistance is (by resistance R
1With resistance R
2Composition), compensating network is (by compensating resistance R
3With building-out capacitor C
2Form).Signal V is switched in the output OUT output one of this switching controller 10
PWM, in order to controlling the change action of power switch in this suitching type circuit 30, and then obtain the stable output voltage V of adjusting in the output of power supply unit
O
This switching controller 10 comprises comparator 162, oscillator 168, D flip-flop 166 and error amplifier 160.Wherein oscillator 168 is in order to produce sawtooth voltage V
SAW, this sawtooth voltage V
SAWCan determine switching signal V
PWMSwitching frequency.The anode of error amplifier 160 is connected to reference voltage V
REF, negative terminal is connected to the feedback end FB of power supply unit, receiving feedback signals V
FBError amplifier 160 is according to reference voltage V
REFWith feedback signal V
FBIn order to output compensating signal V
COM Comparator 162 is connected to oscillator 168 and error amplifier 160, receives sawtooth signal V
SAWWith compensating signal V
COM, via the logical operation of passing through D flip-flop 166 after the comparison operation again, output switching signal V
PWM, and determine this switching signal V
PWMPulse duration.
Cooperate Fig. 1, please refer to Fig. 2, for the known power source supply at the each point signal waveform schematic diagram that starts moment.When power supply unit starts, the feedback signal V that the feedback end FB of power supply unit receives
FBMinimum, therefore, the very big compensating signal V of error amplifier 160 outputs
COM, the compensating signal V that comparator 162 will be very big
COMWith sawtooth voltage V
SAWAfter comparing computing,, export the switching signal V of very big pulse duration again by the logical operation of D flip-flop 166
PWMIn other words, in starting moment and the still unfounded process of output voltage, switching signal V
PWMPulse duration be maximum, and that output voltage is set up the required time is long more, will cause very big voltage and current stress to power switch.
Summary of the invention
In view of this, the invention provides a kind of flexible starter, be used in the power supply unit, be when power supply unit starts, to export a compensating signal to a PWM controller, the pulse duration of this PWM controller output switching signal can produce with cumulative state, be increased to set point gradually by initial value, and after startup is finished, adjusted, so can be used to avoid power switch to cause very big voltage and current stress in the moment of starting shooting according to load condition.
For reaching above-mentioned purpose, the invention provides a kind of flexible starter, be used in the power supply unit, is when this power supply unit starts, export the PWM controller of a compensating signal in this power supply unit, this flexible starter includes: one starts electric capacity; One first power supply connects this startup electric capacity, and this startup electric capacity is charged; One voltage regulation unit, have a first input end, one second input and one first output, this first input end receives a built-in reference voltage, and this second input is connected to this first output and this startup electric capacity, in order to stablize the reference voltage on this startup electric capacity; One error amplifier, have one the 3rd input, a four-input terminal and one second output, the 3rd input connects this startup electric capacity and this first output, this four-input terminal is connected to the feedback end of this power supply unit, this second output is connected to this PWM controller, receive this reference voltage and a feedback signal, in order to export this compensating signal; And a clamping diode, be connected between this four-input terminal and this second output voltage level of this compensating signal of strangulation when this power supply unit starts.
Wherein, this first power supply is a current source, starts electric capacity in order to a charging current to be provided to this.This device also includes one first switch, is connected between the tie point and an earth terminal between this startup electric capacity and first power supply, is controlled by a reset signal, in order to this startup electric capacity is discharged.This device also includes: a second source provides a discharging current; And a second switch, be connected between the tie point and this second source between this startup electric capacity and first power supply, be controlled by a guard signal, allow this discharging current that this startup electric capacity is discharged.When the voltage level of this compensating signal started in this power supply unit, its initial value was the conduction voltage drop of this clamping diode.This voltage regulation unit includes: one is differential to input amplifier, is connected to a current source, receive from this first input end and this second input one differential to input signal, in order to produce an output signal; And an output transistor, the one gate terminal is connected to that this is differential to input amplifier, receives this output signal, and to export this reference voltage, a drain electrode end is connected to this first output, and the one source pole end is connected to earth terminal.This output transistor has out the export structure of the drain electrode or the opener utmost point.
Disclosed flexible starter is when power supply unit is started shooting, and uses one first power supply to start electric capacity to one and charges, and set up a reference voltage in starting on the electric capacity; The first input end of one voltage regulation unit receives a built-in reference voltage, second input is connected to first output and this startup electric capacity, this voltage regulation unit has out the export structure of the drain electrode (open-drain) or the opener utmost point (open-collect), makes that the reference voltage on this startup electric capacity is stabilized in the built-in reference voltage;
-error amplifier, its 3rd input connects this startup electric capacity and first output, receives this reference voltage, the one four-input terminal is connected to the feedback end of power supply unit, to receive a feedback signal, one second output is connected to this PWM controller, in order to export this compensating signal.One clamping diode is connected to this four-input terminal and this second output, the voltage level of this compensating signal of strangulation when power supply unit starts.
When power supply unit is started shooting moment, this first power supply charges to this startup electric capacity and is charged to this reference voltage, make this compensating signal increase gradually, thereby make the pulse duration of switching signal be increased to set point gradually by initial value along with the slow rising of this reference voltage.The cumulative purpose that reaches flexible startup of this compensating signal.
Being noted that above general introduction and ensuing detailed description are all exemplary in nature, is in order to further specify claim of the present invention.And about other purpose of the present invention and advantage, will be set forth in follow-up explanation and diagram.
Description of drawings
Fig. 1 is the circuit box schematic diagram of known power source supply;
Fig. 2 is that the known power source supply is at the each point signal waveform schematic diagram that starts moment;
Fig. 3 is used in the circuit diagram of power supply unit for flexible starter of the present invention;
Fig. 4 is that the present invention is at the each point signal waveform schematic diagram that starts moment; And
Fig. 5 is the circuit diagram of voltage regulation unit of the present invention.
Wherein, description of reference numerals is as follows:
Known:
10 switching controllers, 160 error amplifiers
162 comparators, 166 D flip-flops
168 oscillator R
1, R
2Resistance
R
3Compensating resistance C
1Output capacitance
C
2Building-out capacitor L outputting inductance
30 suitching type circuit
The present invention:
30 suitching type circuit, 40 flexible starters
C
SSStart electric capacity 402 error amplifiers
403 second switches, 404 clamping diodes
405 first switches, 406 voltage regulation units
4060 current sources, 4061,4062,4063,4064 transistors
4065 resistance, 4066 electric capacity
4067 output transistors, 407 first power supplys
408 second sources, 50 PWM controller
502 comparators, 504 oscillators
506 D flip-flop R
1, R
2Resistance
R
3Compensating resistance C
1Output capacitance
C
2Building-out capacitor L outputting inductance
Embodiment
Please refer to Fig. 3, be used in the circuit diagram of power supply unit for flexible starter of the present invention.Flexible starter 40 is connected in the feedback end FB of a PWM controller 50 and power supply unit.Wherein feedback end FB passes through divider resistance (by resistance R
1With resistance R
2Composition) is connected to output voltage V
O
Refer again to Fig. 3, flexible starter 40 of the present invention includes one first power supply 407, and starts capacitor C
SS, a voltage regulation unit 406, an error amplifier 402 and a clamping diode 404.Wherein first power supply 407 is connected to the startup capacitor C
SS, and to starting capacitor C
SSCharge, and on this startup electric capacity, set up a reference voltage V
REF Voltage regulation unit 406 utilizes its first input end (+) to receive built-in reference voltage V
R, and second input (-) is connected to first output and starts capacitor C
SSTo form a unity gain buffer, this voltage regulation unit 406 has out the export structure of the drain electrode (open-drain) or the opener utmost point (open-collect), and then will start capacitor C
SSOn reference voltage V
REFBe stabilized in built-in reference voltage V
RWithin.
The 3rd input (+) of error amplifier 402 is connected to the startup capacitor C
SSWith first output, its four-input terminal (-) is connected to the feedback end FB of power supply unit, and its second output is connected to PWM controller 50, and error amplifier 402 is with reference voltage V
REFWith feedback signal V
FBError amplify, in order to output compensating signal V
COMClamping diode 404 is connected to four-input terminal (-) and second output, when power supply unit starts, is used for strangulation compensating signal V
COMVoltage level be the conduction voltage drop V of clamping diode 404
F
In the above-mentioned explanation, start moment, the reference voltage V that error amplifier 402 the 3rd input (+) receives at power supply unit
REFCan be along with starting capacitor C
SSOn charging voltage rise gradually, when it rises to built-in reference voltage V
RThe time enter normal condition.The output-voltage levels of this clamping diode 404 strangulation error amplifier 402 when power supply unit starts simultaneously.That is to say,, be connected to the startup capacitor C starting moment
SSThe 3rd input (+) be connected to the four-input terminal (-) of the feedback end FB of power supply unit, both voltage is all zero volt, by this clamping diode 404 strangulation compensating signal V
COMVoltage level, make the initial value of output-voltage levels of error amplifier 402 be the conduction voltage drop V of this clamping diode 404
F
If the four-input terminal (-) of error amplifier 402 does not add clamping diode 404 with second output,, be connected to the startup capacitor C starting moment
SSThe voltage of the 3rd input (+) be zero volt, can by error amplifier 402 with voltage gain amplify from the feedback signal that the feedback end FB of power supply unit obtains this moment, makes the compensating signal V of second output output of error amplifier 402
COMThe very fast arrival saturation voltage of meeting, causing does not have the flexible effect that starts.
Refer again to Fig. 3, this first power supply 407 is a current source, in order to this is started capacitor C
SSCharging current is provided.Start moment at power supply unit, this starts capacitor C
SSVoltage rise gradually, this starts capacitor C
SSCan be by the self capacity value in order to plan its start-up time.The startup capacitor C of big capacitance
SSTo increase start-up time, and then it is specified to reduce the voltage and the electric current of power switch.Therefore, this starts capacitor C by rational selection
SSCapacitance, make starting the time of delay that moment causes can be in suitable scope.
Refer again to Fig. 3, this PWM controller 50 comprises oscillator 504, comparator 502 and D flip-flop 506.Wherein this oscillator 504 is limited to high critical voltage V in order to produce on one
TH2, be limited to low critical voltage V down
TH1Sawtooth voltage V
SAWThe anode (+) of comparator 502 is connected to second output of error amplifier 402, and its negative terminal (-) is connected to oscillator 504, receives comparison operation compensating signal V simultaneously
COMWith sawtooth signal V
SAW, operation result then is sent to D flip-flop 506, by the logical operation of D flip-flop 506, and output and decision switching signal V
PWMPulse duration.
Cooperate Fig. 3, with reference to figure 4, for the present invention at the each point signal waveform schematic diagram that starts moment.Startup moment during the power supply unit start, cooperate to start capacitor C
SSCharging, starting capacitor C
SSOn reference voltage V
REFBegin to rise by zero volt.Because voltage regulation unit 406 is a unity gain buffer, this voltage regulation unit 406 has out the export structure of the drain electrode (open-drain) or the opener utmost point (open-collect), so reference voltage V
REFMaximum can be stabilized in built-in reference voltage V
RWhen the 3rd input (+) of error amplifier 402 is zero volt, be subjected to the effect that clamping diode 404 has the strangulation voltage level, second output of error amplifier 402 is clamped at the conduction voltage drop V of this clamping diode 404
F(generally about 0.7V), the conduction voltage drop V of this moment
FStill be lower than sawtooth signal V
SAWLow critical voltage V
TH1At the same time, along with reference voltage V
REFRising gradually, compensating signal V
COMAlso increase gradually.Starting capacitor C
SSCharging process in, switching signal V
PWMPulse duration begin slowly to increase by initial value, up to reference voltage V
REFReach built-in reference voltage V
R, the pulse duration of this moment reaches set point, and is adjusted according to load condition after startup is finished, thereby reaches flexible startup.
Please refer to Fig. 5, be the circuit diagram of voltage regulation unit of the present invention.This voltage regulation unit 406 is brought in external circuitry by first input end (+), second input (-) and first output and is connected, its inside include by transistor 4061,4062,4063 and 4064 formed one differential to input amplifier (differential-pair input amplifier), current source 4060, resistance 4065, electric capacity 4066 and output transistor 4067.Wherein differential input amplifier is connected to current source 4060, and receive by the first input end (+) and second input (-) one differential to input signal, in order to produce an output signal V
OUTThe gate terminal of output transistor 4067 is connected to differential to input amplifier, receives this output signal V
OUTTo produce amplifying signal, be this reference voltage V
REFThe drain electrode end of output transistor 4067 is connected to this first output, and its source terminal is connected to earth terminal.It is resistance 4065 and electric capacity 4066 that the gate terminal of output transistor 4067 and drain electrode end are connected with a RC circuit, in order to the effect that affords redress.This drain electrode end of this output transistor 4067 is connected to first output of this voltage regulation unit 406, in order to the export structure of the drain electrode (open-drain) or the opener utmost point (open-collect) to be provided out.
Refer again to Fig. 3, wherein the present invention also includes first switch 405 and is connected in this startup capacitor C
SSWith earth terminal.When power supply unit does not provide power output, according to feedback signal V
FBVoltage level, in order to output reset signal RST controlling 405 conductings of first switch, and then to starting capacitor C
SSDischarge and start the purpose of resetting to reach.Other has second source 408 to be connected to the startup capacitor C by second switch 403
SS, according to the switching of second switch 403, in order to provide discharging current to starting capacitor C
SSDischarge.The switching of second switch 403 is controlled by guard signal PTN.When power supply unit generation overpower, short circuit and overvoltage, according to feedback signal V
FBVoltage level, in order to output protection signal PTN, and to starting capacitor C
SSDischarge, to reach the purpose of protection.
In sum, flexible starter provided by the present invention, be used in the power supply unit, and the output compensating signal arrives PWM controller when power supply unit starts, the pulse duration of this PWM controller output switching signal can produce with cumulative state, be increased to set point gradually by initial value, and after startup is finished, adjusted, so can be used to avoid power switch to cause very big voltage and current stress in the moment of starting shooting according to load condition.
Yet, the above only is the detailed description and the accompanying drawing of the specific embodiment of one of the best of the present invention, feature of the present invention is not limited thereto, be not in order to restriction the present invention, all scopes of the present invention should be as the criterion with following claims, all closing in the embodiment of the spirit variation similar of claims of the present invention with it, all should be contained in the category of the present invention, those skilled in the art in the field of the invention, can think easily and variation or modify all can be encompassed in the claim of the present invention.
Claims (7)
1. a flexible starter is used in the power supply unit, is when this power supply unit starts, and exports the PWM controller of a compensating signal in this power supply unit, it is characterized in that this flexible starter includes:
One starts electric capacity;
One first power supply connects this startup electric capacity, and this startup electric capacity is charged;
One voltage regulation unit, have a first input end, one second input and one first output, this first input end receives a built-in reference voltage, and this second input is connected to this first output and this startup electric capacity, in order to stablize the reference voltage on this startup electric capacity;
One error amplifier, have one the 3rd input, a four-input terminal and one second output, the 3rd input connects this startup electric capacity and this first output, this four-input terminal is connected to the feedback end of this power supply unit, this second output is connected to this PWM controller, receive this reference voltage and a feedback signal, in order to export this compensating signal; And
One clamping diode is connected between this four-input terminal and this second output, the voltage level of this compensating signal of strangulation when this power supply unit starts.
2. flexible starter as claimed in claim 1, wherein, this first power supply is a current source, starts electric capacity in order to a charging current to be provided to this.
3. flexible starter as claimed in claim 1 wherein, also includes one first switch, is connected between the tie point and an earth terminal between this startup electric capacity and first power supply, is controlled by a reset signal, in order to this startup electric capacity is discharged.
4. flexible starter as claimed in claim 1 wherein, also includes:
One second source provides a discharging current; And
One second switch is connected between the tie point and this second source between this startup electric capacity and first power supply, is controlled by a guard signal, allows this discharging current that this startup electric capacity is discharged.
5. flexible starter as claimed in claim 1, wherein, when the voltage level of this compensating signal started in this power supply unit, its initial value was the conduction voltage drop of this clamping diode.
6. flexible starter as claimed in claim 1, wherein, this voltage regulation unit includes:
One is differential to input amplifier, is connected to a current source, receive from this first input end and this second input one differential to input signal, in order to produce an output signal; And
One output transistor, one gate terminal are connected to that this is differential to input amplifier, receive this output signal, and to export this reference voltage, a drain electrode end is connected to this first output, and the one source pole end is connected to earth terminal.
7. flexible starter as claimed in claim 6, wherein, this output transistor has out the export structure of the drain electrode or the opener utmost point.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB2005100082110A CN100423433C (en) | 2005-02-07 | 2005-02-07 | Flexible starter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB2005100082110A CN100423433C (en) | 2005-02-07 | 2005-02-07 | Flexible starter |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1819429A CN1819429A (en) | 2006-08-16 |
| CN100423433C true CN100423433C (en) | 2008-10-01 |
Family
ID=36919167
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB2005100082110A Expired - Fee Related CN100423433C (en) | 2005-02-07 | 2005-02-07 | Flexible starter |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN100423433C (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8559196B2 (en) * | 2009-03-12 | 2013-10-15 | System General Corp. | Output voltage control circuit of power converter for light-load power saving |
| CN102270969A (en) * | 2010-06-04 | 2011-12-07 | 原景科技股份有限公司 | Light-emitting diode circuit and error amplifier thereof |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5264782A (en) * | 1992-08-10 | 1993-11-23 | International Business Machines Corporation | Dropout recovery circuit |
| CN2333473Y (en) * | 1998-07-15 | 1999-08-18 | 广州市东山区长胜焊接设备厂 | Controller for inverter argon arc welding machine |
| CN1063899C (en) * | 1993-08-31 | 2001-03-28 | 汤姆森消费电子有限公司 | AKB apparatus with hot start flash prevention |
| US20040228152A1 (en) * | 2003-05-14 | 2004-11-18 | Intersil Americas Inc., State Of Incorporation: Delaware | Soft start precharge circuit for DC power supply |
| CN2774005Y (en) * | 2005-02-28 | 2006-04-19 | 崇贸科技股份有限公司 | Flexible starter |
-
2005
- 2005-02-07 CN CNB2005100082110A patent/CN100423433C/en not_active Expired - Fee Related
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5264782A (en) * | 1992-08-10 | 1993-11-23 | International Business Machines Corporation | Dropout recovery circuit |
| CN1063899C (en) * | 1993-08-31 | 2001-03-28 | 汤姆森消费电子有限公司 | AKB apparatus with hot start flash prevention |
| CN2333473Y (en) * | 1998-07-15 | 1999-08-18 | 广州市东山区长胜焊接设备厂 | Controller for inverter argon arc welding machine |
| US20040228152A1 (en) * | 2003-05-14 | 2004-11-18 | Intersil Americas Inc., State Of Incorporation: Delaware | Soft start precharge circuit for DC power supply |
| CN2774005Y (en) * | 2005-02-28 | 2006-04-19 | 崇贸科技股份有限公司 | Flexible starter |
Also Published As
| Publication number | Publication date |
|---|---|
| CN1819429A (en) | 2006-08-16 |
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Granted publication date: 20081001 Termination date: 20130207 |