CN2877127Y - Control circuit with frequency modulation for decreasing electromagnetic interference of power converter - Google Patents
Control circuit with frequency modulation for decreasing electromagnetic interference of power converter Download PDFInfo
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- CN2877127Y CN2877127Y CNU2005201430639U CN200520143063U CN2877127Y CN 2877127 Y CN2877127 Y CN 2877127Y CN U2005201430639 U CNU2005201430639 U CN U2005201430639U CN 200520143063 U CN200520143063 U CN 200520143063U CN 2877127 Y CN2877127 Y CN 2877127Y
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Abstract
A frequency-modulation control circuit is provided for reducing electromagnetic interference of a power converter, which comprises a switching circuit coupled with a feedback circuit to produce switch signals to modulate an output of the power converter, a first oscillator for defining switch frequency of the switch signals, a second oscillator coupled with the first oscillator to modulate switch frequency of the switch signals and thus to reduce the electromagnetic interference of the power converter, and a digital control resistor for attenuating a feedback signal of the feedback circuit. The output of second oscillator is coupled to the digital control resistor numerical control, so as to control resistance value of the digital control resistor. Therefore, even when the switch frequency is modulated, the output power and output voltage are maintained constant.
Description
Technical field
The utility model is about a kind of power supply changeover device, and particularly about a kind of control of switch type power converter.
Background technology
Power supply changeover device (power converter) is to be used for converting a unregulated supply to a voltage or an electric current of regulating.Fig. 1 illustrates a conventional power source transducer, and wherein a control circuit 10 is to include a frequency setting end RT, a back coupling end FB, a switching output SW and a current sense end VS, and wherein this control circuit 10 produces a switching signal V
SW, switch a transformer 30 in order to control a transistor 20.One resistor 40 is to be used for one of this transformer 30 of sensing to switch electric current I
PTo carry out switching controls.One resistor 45 is with a switching frequency that decides this control circuit 10.This back coupling end FB of this control circuit 10 is an output that is connected to a feedback circuit 50.This feedback circuit 50 is to be coupled to the output of power supply changeover device to produce a feedback signal V
FBAccording to this feedback signal V
FB, this switching signal V
SWWork period (duty cycle) be the power that has determined to be sent to the output of power supply changeover device from the input of power supply.Though handoff technique makes that the volume of power supply changeover device is dwindled, (electric and magnetic interference EMI) has influenced power supply and ancillary equipment thereof to the electromagnetic interference that changeover module produced.Therefore need to dispose the solution (for example electromagnetic interface filter, transformer screen protect etc.) of electromagnetic interference in the power supply changeover device, to reduce electromagnetic interference.Yet the solution of electromagnetic interference but causes the loss of power, has also increased the volume and the cost of power supply changeover device simultaneously.In the immediate development, many prior aries all reduce electromagnetic interference at this frequency of utilization modulation (frequency modulation) or frequency hopping means such as (frequency hopping).Prior art " Reduction of Power Supply EMIEmission by Switching Frequency Modulation " (IEEE Transactions onPower Electronics for example, VOL.9.No.1.January 1994), " Effects of SwitchingFrequency Modulation on EMI Performance of a Converter Using SpreadSpectrum Approach " (Applied Power Electronics Conference andExposition, 2002,17-Annual, IEEE, Volume 1,10-14, March, 2002, Pages:93-99), United States Patent (USP) announces the 6th, 229, No. 366 " Offline Converter withIntegrated Softstart and Frequency Jitter " (May 8,2001) and United States Patent (USP) announce the 6th, 249, No. 876 " Frequency Jittering Control for Varying theSwitching Frequency of a Power Supply " (Jun.19,2001) or the like.Yet the shortcoming of prior art is that " frequency modulating " can produce unexpected ripple signal (ripple signal) in the output of power supply changeover device.
Being produced unexpected ripple signal by frequency modulating will be described as follows.The power output P of power supply changeover device
OIt is the output voltage V of power supply changeover device
OWith output current I
OProduct, its relational expression is:
P
O＝V
O×I
O＝η×P
IN---------------------(1)
The input power P of this transformer 30
INWith switch current I
PRelation is shown below:
Wherein η is the efficient (efficiency) of transformer 30, V
INBe the input voltage of transformer 30, L
PBe the primary side inductance (primary inductance) of transformer 30, T is switching signal V
SWSwitching cycle (switching period), T
ONBe switching signal V
SWON time (on-time).
Equation (1) can be rewritten as
Owing to switching cycle T changes according to frequency modulating.Shown in equation (2), when switching cycle T changes, power output P
OWill change.Therefore, as power output P
ODuring change, will produce unexpected ripple signal.
The other shortcoming of prior art is unexpected frequency modulating scope.Its frequency modulating scope is relevant with the setting of switching frequency.Therefore, when setting its switching frequency according to different application, the effect that reduces electromagnetic interference is unclear with making.
The utility model content
The purpose of this utility model provides a kind of control circuit with frequency modulating, to reduce the electromagnetic interference (EMI) of power supply changeover device (power converter).
Another purpose of the present utility model provides a kind of control circuit with frequency modulating, to avoid producing unexpected ripple signal in the output of power supply changeover device.
Based on above-mentioned and other purpose, the utility model proposes a kind of control circuit with frequency modulating, in order to control a power supply changeover device, this control circuit comprises that one switches circuit, one first oscillator, one second oscillator, a numerical control capacitor and a digit-control resistance device.This commutation circuit is coupled to a feedback circuit, in order to produce switching signal to regulate an output of power supply changeover device.Wherein, this feedback circuit is this output that is coupled to power supply changeover device, so that the feedback signal in order to the control switching signal to be provided.This first oscillator is connected to this commutation circuit, in order to produce a pulse signal to determine the switching frequency of this switching signal.This numerical control capacitor is connected to this first oscillator, in order to the frequency of this pulse signal of modulation.Second oscillator produces an oscillator signal, and wherein this second oscillator comprises a coding circuit, in order to produce a data signal groups according to this oscillator signal.This digit-control resistance device is coupled to this feedback circuit, in order to this feedback signal that decays.Wherein, this data signal groups is in order to controlling the switching frequency of this numerical control capacitor with this switching signal of modulation, and is used for controlling this digit-control resistance device to determine the attenuation rate of this feedback signal.
From another viewpoint, the utility model proposes a kind of control circuit, in order to control a power supply changeover device with frequency modulating.This control circuit comprises that one switches circuit, one first oscillator, one second oscillator, a numerical control capacitor and a digit-control resistance device.This commutation circuit is to be coupled to a feedback circuit, switches signal to regulate an output of this power supply changeover device in order to produce one.Wherein, this feedback circuit is this output that is coupled to this power supply changeover device, so that the feedback signal in order to the control switching signal to be provided.This first oscillator is to be coupled to this commutation circuit, in order to determine the switching frequency of this switching signal.This numerical control capacitor is coupled to this first oscillator, in order to the switching frequency of this switching signal of modulation.This second oscillator is in order to produce an oscillator signal, and wherein an analog-digital converter is coupled to this second oscillator, in order to produce a data signal groups according to this oscillator signal.This digit-control resistance device is to be coupled to this feedback circuit, in order to this feedback signal that decays.Wherein, this data signal groups is in order to the capacitance of controlling this numerical control capacitor and the resistance value of this digit-control resistance device.
The utility model proposes a kind of controller, in order to the control power supply changeover device with frequency modulating.This controller comprises that one switches circuit, one first oscillator, one second oscillator and a digit-control resistance device.This commutation circuit is to be coupled to a feedback circuit, switches signal to regulate an output of power supply changeover device in order to produce one.Wherein, this feedback circuit is this output that is coupled to this power supply changeover device, to provide in order to control a feedback signal of this switching signal.This first oscillator is to be coupled to this commutation circuit, in order to determine the switching frequency of this switching signal.This second oscillator is to be coupled to this first oscillator, in order to the switching frequency of this switching signal of modulation.This digit-control resistance device is coupled to this feedback circuit, in order to this feedback signal that decays.Wherein, this second oscillator is to be coupled to this digit-control resistance device, to control the resistance value of this digit-control resistance device.
The utility model proposes a kind of control circuit with frequency modulating in addition, in order to the control power supply changeover device.This control circuit comprises that one switches circuit, one first oscillator and one second oscillator.This commutation circuit is coupled to a feedback circuit, in order to produce this switching signal to regulate an output of this power supply changeover device.Wherein, this feedback circuit is this output that is coupled to this power supply changeover device, switches a feedback signal of signal so that control one to be provided.This first oscillator is coupled to this commutation circuit, in order to determine the switching frequency of this switching signal.This second oscillator produces an oscillator signal, and wherein this second oscillator comprises a coding circuit, produces a data signal groups in order to the foundation oscillator signal.Wherein, this data signal groups is to be coupled to this first oscillator, in order to the switching frequency of this switching signal of modulation.
The utility model because of modulation the switching frequency of this switching signal, therefore launched to switch the frequency spectrum of energy, thereby reduced the electromagnetic interference of power supply changeover device.In addition, because this data signal groups has been controlled the attenuation rate (it is controlling an ON time of this switching signal) of this feedback signal, therefore can be by compensating its variation by this switching frequency modulation, and keeping power output and output voltage is definite value, to avoid producing unexpected ripple signal in the output of power supply changeover device.
For above-mentioned and other purpose, feature and advantage of the present utility model can be become apparent, preferred embodiment cited below particularly, and cooperate appended graphicly, be described in detail below.
Description of drawings
Fig. 1 illustrates explanation one existing power supply transducer;
Fig. 2 is the circuit diagram that illustrates a control circuit of the present utility model;
Fig. 3 is the calcspar that illustrates an oscillating circuit of the present utility model;
Fig. 4 is the circuit diagram that illustrates one second oscillator of the present utility model;
Fig. 5 is the circuit diagram that illustrates a coding circuit of the present utility model;
Fig. 6 is an oscillator signal oscillogram that illustrates this second oscillator of the present utility model;
Fig. 7 is the circuit diagram that illustrates one first oscillator of the present utility model;
Fig. 8 is a serrated signal and a pulse signal waveform figure who illustrates this first oscillator of the present utility model;
Fig. 9 illustrates the circuit diagram of the utility model in order to two current sources of decision switching frequency.
[primary clustering symbol description]
10: control circuit
20,361～366: transistor
30: transformer
40,45,90～99: resistor
50: feedback circuit
70,104～109,220: inverter
71,72,230,235,251～255,330,335: comparator
73,79: with door
75,261～265: flip-flop
80: diode
84～89,227,228,327,328,351～359: switch
100: oscillating circuit
101: the digit-control resistance device
200: the second oscillators
210,311～319,320: capacitor
225,226,325,326: current source
240,245,340,345: NAND gate
250: coding circuit
270: encoder
300: the first oscillators
360: amplifier
500: the numerical control capacitor
FB: feedback and hold
N
n～N
0: data signal groups
PLS: pulse signal
RT: frequency setting end
SW: switch output
SAW: serrated signal
V
FB: feedback signal
V
FB': the decay feedback signal
V
IN: input voltage
V
HS: reference signal on first
V
HM: reference signal on second
V
LS: first time reference signal
V
LM: second time reference signal
V
O: output voltage
VS: current sense end
V
S: the switch current signal
V
SW: switching signal
V
T: reference voltage
WAV: oscillator signal
Embodiment
Fig. 1 illustrates a kind of conventional power source transducer.One control circuit 10 is to be coupled to a feedback circuit 50, switches signal V to produce one
SWAnd the output of adjusting power supply changeover device, this feedback circuit 50 is the output that is coupled to power supply changeover device, to produce a feedback signal V
FBThis switching signal V wherein
SWBe according to this feedback signal V
FBAnd change.One of one transformer 30 switches electric current I
PBe to be converted into one to switch current signal V via a sense resistor 40
SThis switch current signal V
SOffer this control circuit 10, produce this switching signal V according to this
SW
Fig. 2 is the circuit diagram that illustrates control circuit 10 of the present utility model.In control circuit 10, one switch circuit comprise comparator 71,72, flip-flop 75, inverter 70, with door 73,79, diode 80 and resistor 90,91,92,93.Resistor 90 is in order to draw high a back coupling end FB.This feedbacks end FB with this feedback signal V
FBBe connected to resistor 91 via diode 80.Diode 80 makes this feedback signal V
FBAccurate bit shift.Resistor the 91,92, the 93rd, this feedback signal that decays V
FB, to reduce the feedback loop (feedback loop) of loop gain (loop gain) in order to the stabilized power supply transducer.This resistor 92 is connected between this resistor 91 and this resistor 93, and these resistor 93 ground connection.Resistor 91 and this comparator 71 positive inputs of being connected of 92 produce a decay feedback voltage V
FB'.This switch current signal V
SIt is the negative input that is supplied to this comparator 71.Via this and door 73, the output of this comparator 71 is to be coupled to this replacement end of positive and negative 75.This switch current signal V
SMore be supplied to a negative input of this comparator 72.One positive input of this comparator 72 is by a reference voltage V
TSupply.Via this and door 73, one of this comparator 72 is exported this flip-flop 75 that also is used to reset.One pulse signal PLS triggers this flip-flop 75 via this inverter 70.One output of this inverter 70 more is connected to this and a door input of 79.Should then be connected to an output of this flip-flop 75 with another input of door 79.Should produce this switching signal V with an output of door 79
SWTherefore, this switching signal V
SWSwitch according to this pulse signal PLS.In case this switch current signal V
SBe higher than this decay feedback voltage V
FB' and this reference voltage V
T, switching signal V
SWTo be closed (turned off) immediately.
One oscillating circuit 100 produces this pulse signal PLS and data signal groups N
N～N
OOne resistor 45 sees through a link RT and connects this oscillating circuit 100, in order to determine the frequency of oscillation of this pulse signal PLS.One digit-control resistance device 101 is in parallel with this resistor 93, in order to set this feedback signal V
FBAttenuation rate.This digit-control resistance device 101 comprises that many groups convert resistance parallel with one another is right, and wherein each convert resistance is to being formed by resistor 99～94 and switch 89～84 difference.Wherein switch 84 is connected with resistor 94.Switch 89 is connected with resistor 99.Data signal groups N
n～N
0Controlling switch 89～84 via inverter 109～104, to change the resistance value of this digit-control resistance device 101.
With reference to figure 3, this oscillating circuit 100 comprises one first oscillator 300 and second oscillator 200.This first oscillator 300 produces this pulse signal PLS, and this second oscillator then produces data signal groups N
n～N
0This link RT is connected to this first oscillator 300.Fig. 4 is the circuit diagram that illustrates this second oscillator 200 of the present utility model.This second oscillator 200 comprises a current source 225, and in order to produce a charging current, 226 of current sources produce a discharging current.One switch 227 is to be connected between this current source 225 and the capacitor 210.One switch 228 is to be connected between this current source 226 and this capacitor 210.Therefore on this capacitor 210, produce an oscillator signal WAV.Reference voltage V on one first
HSOne first input to a comparator 230 is provided.One second input of this comparator 230 is connected to this capacitor 210.One first time reference voltage V
LSOne second input to a comparator 235 is provided.One first input of this comparator 235 is to be connected to this capacitor 210.This reference voltage V on first
HSBe to be higher than this first time reference voltage V
LSOne output of this comparator 230 is one first inputs that are connected to a NAND gate 240, and an output of this NAND gate 240 is in order to keying (turn on/off) this switch 228, and this output of this NAND gate 240 more sees through an inverter 220 in order to open and close this switch 227.Two inputs of one NAND gate 245 are connected to this output of this NAND gate 240 and an output of this comparator 235 respectively.One output of NAND gate 245 is one second inputs that are connected to this NAND gate 240.One coding circuit 250 is to produce this data signal groups N according to this oscillator signal WAV
n～N
0
Fig. 5 is the circuit diagram that illustrates this coding circuit 250 of the present utility model.Operation at this this coding circuit 250 can be considered an analog-digital converter.This coding circuit 250 comprises comparator 251～255, and the quantity of comparator 251～255 can the arbitrary decision according to needs.The positive input of comparator 251～255 is supplied by oscillator signal WAV.Reference voltage V
R1～V
R5Be supplied to the negative input of comparator 251～255 respectively.The input of flip-flop 261～265 is coupled to the output of comparator 251～255 respectively.The pulse input of flip-flop 261～265 is supplied by this pulse signal PLS.Therefore the output state of comparator 251～255 promptly is latched respectively in flip-flop 261～265 according to this pulse signal PLS.One encoder 270 is the output that is coupled to flip-flop 261～265, in order to produce data signal groups N
n～N
0
Fig. 6 is the oscillogram that illustrates this oscillator signal WAV of the present utility model.Data signal groups N
n～N
0Be to produce according to this oscillator signal WAV.T among the figure
HThe cycle of representing this oscillator signal WAV.
Fig. 7 is the circuit diagram that illustrates this first oscillator 300 of the utility model.First oscillator 300 comprises a current source 325, in order to produce a charging current I
325326 of one current sources are used for producing a discharging current I
326One capacitor 320 is in parallel with a numerical control capacitor 500.This numerical control capacitor 500 is to composing in parallel by many groups switch-capacitor.Each switch-capacitor is to being to be connected respectively with switch 351～359 and formed by capacitor 311～319, and wherein switch 351～359 is respectively according to data signal groups N
n～N
0And open and close.Therefore, for the modulation switching frequency, the capacitance of numerical control capacitor 500 can be by data signal groups N
n～N
0And set.
One switch 327 is to be connected between this current source 325 and this capacitor 320.One switch 328 is to be connected between this current source 326 and this capacitor 320.Reference voltage V on one second
HMBe supplied to one first input of a comparator 330.One second input of this comparator 330 is to be connected to this capacitor 320.One second time reference voltage V
LMBe supplied to one second input of a comparator 335.One first input of this comparator 335 is to be connected to this capacitor 320.This reference voltage V on second
HMBe higher than this second time reference voltage V
LMOne NAND gate 340 is in order to produce this pulse signal PLS, to determine this switching signal V
SWSwitching frequency.One output play of this comparator 330 is coupled to one first input of this NAND gate 340.This output of this NAND gate 340 is in order to open and close this switch 328.Two inputs of one NAND gate 345 are connected to this output of this NAND gate 340 and an output of this comparator 335 respectively.This output of this NAND gate 345 is one second input that is connected to this NAND gate 340.This output of this NAND gate 345 is in order to open and close this switch 327.Therefore produce a serrated signal SAW at capacitor 320.
Fig. 8 is the example oscillogram that illustrates this serrated signal SAW of the present utility model and this pulse signal PLS.T among the figure
SWThe cycle of representing this serrated signal SAW.The frequency of this serrated signal SAW and this pulse signal PLS is by this charging current I
325, this discharging current I
326, this capacitor 320 determines with numerical control capacitor 500.At this, this charging current I
325With this discharging current I
326Produced by circuit shown in Figure 9.
Fig. 9 is the circuit diagram that this current source 325 and current source 326 are described according to the utility model embodiment.This current source 325 includes with this current source 326: amplifier 360, transistor 361, resistor 45 and current mirror.This current mirror is made up of 362～366 in transistor.In the embodiment of Fig. 9, resistor 45 is in order to the decision switching frequency.Amplifier 360 is according to an electric current I that is connected in the resistor 45 generation transistors 361 on the frequency setting end RT
361According to the preset ratio of this current mirror, this electric current I
361Will be respectively by going out this charging current I by a transistor 364 and a transistor 366 mirrors
325With this discharging current I
326
Data signal groups N
n～N
0Be to change data signal groups N according to the oscillator signal WAV of this two oscillator 200
n～N
0Change be that the switching frequency that sets with this first oscillator 300 is irrelevant.When by data signal groups N
n～N
0When setting this numerical control capacitor 500, promptly accordingly modulation this switching signal V
SWSwitching frequency.The frequency spectrum that switches energy promptly is unfolded, and has reduced the electromagnetic interference of power supply changeover device.Please refer to equation (2), changed the power output of power supply changeover device owing to the modulation of switching cycle T.Data signal groups N
n～N
0More controlled this feedback signal V
FBAttenuation rate, and then control this switching signal V
SWON time T
ONTherefore, by compensating its variation, be certain value to keep power output and output voltage by the switching frequency modulation.
Though the utility model discloses as above with preferred embodiment; right its is not in order to limit the utility model; anyly have the knack of this skill person; in not breaking away from spirit and scope of the present utility model; when doing a little change and retouching, therefore protection range of the present utility model is as the criterion when looking accompanying the claim person of defining.
Claims (15)
1. the control circuit with frequency modulating in order to control a power supply changeover device, is characterized in that, this control circuit comprises:
One switches circuit, is coupled to a feedback circuit, switches signal to regulate an output of this power supply changeover device in order to produce one, and wherein this feedback circuit is this output that is coupled to this power supply changeover device, so that a feedback signal of this switching signal of control to be provided;
One first oscillator is coupled to this commutation circuit, in order to produce a pulse signal to determine the switching frequency of this switching signal;
One numerical control capacitor is coupled to this first oscillator, in order to the frequency of this pulse signal of modulation;
One digit-control resistance device is coupled to this feedback circuit, in order to this feedback signal that decays; And
One second oscillator, in order to produce an oscillator signal, wherein this second oscillator includes a coding circuit to produce a data signal groups according to this oscillator signal; Wherein this data signal groups is in order to controlling the switching frequency of this numerical control capacitor with this switching signal of modulation, and in order to control this digit-control resistance device to determine the attenuation rate of this feedback signal.
2. control circuit as claimed in claim 1 is characterized in that, described this numerical control capacitor comprises:
Many group switch-capacitors are right, and those switch-capacitors are to being connected in parallel to each other, and wherein those switch-capacitors are to being formed by many groups of indivedual regulating switch and modulation capacitors of connecting, and those regulating switch systems control its keying by this data signal groups.
3. control circuit as claimed in claim 1 is characterized in that, described this digit-control resistance device comprises:
Many group convert resistances are right, and those convert resistances are to being connected in parallel to each other, wherein those convert resistances to be by the attenuator switch of many groups of indivedual series connection and damping resistance device couple mutually form, those attenuator switch are to control its keying by this data signal groups.
4. control circuit as claimed in claim 1 is characterized in that, described this first oscillator comprises:
One charging current source is in order to produce a charging current;
One discharging current source is in order to produce a discharging current;
One oscillating capacitor is to be in parallel with this numerical control capacitor;
One charge switch is to be connected between this charging current source and this oscillating capacitor;
One discharge switch is connected between this discharging current source and this oscillating capacitor;
One first comparator, one first input is supplied by one first reference voltage, and one second input is to be connected to this oscillating capacitor;
One second comparator, one first input is to be connected to this oscillating capacitor, and one second input is supplied by one second reference voltage, and wherein this first reference voltage is to be higher than this second reference voltage;
One first lock, in order to produce this pulse signal to determine the switching frequency of this switching signal, wherein one first of this first lock input is an output that is coupled to this first comparator, wherein one of this first lock output is in order to open and close this discharge switch; And
One second lock, its two inputs are connected to this output of this first lock and an output of this second comparator respectively, and an output of this second lock is one second input that is connected to this first lock, wherein one of this second lock output is in order to open and close this charge switch.
5. control circuit as claimed in claim 1 is characterized in that, described this coding circuit comprises:
A plurality of comparators, the positive input of those comparators are to be connected to this oscillator signal, and the negative input of those comparators is supplied by corresponding many group reference voltages respectively;
A plurality of flip-flops, the input of those flip-flops are the output that is coupled to those comparators respectively, and wherein the pulse of those flip-flops input is supplied by this pulse signal; And
One encoder is coupled to the output of those flip-flops, in order to produce this data signal groups.
6. the control circuit with frequency modulating in order to control a power supply changeover device, is characterized in that, this control circuit comprises:
One switches circuit, is coupled to a feedback circuit, switches signal to regulate an output of this power supply changeover device in order to produce one, and wherein this feedback circuit is this output that is coupled to this power supply changeover device, so that a feedback signal of this switching signal of control to be provided;
One first oscillator is coupled to this commutation circuit, in order to determine the switching frequency of this switching signal;
One numerical control capacitor is coupled to this first oscillator, in order to the switching frequency of this switching signal of modulation;
One second oscillator, in order to produce an oscillator signal, wherein this second oscillator includes an analog-digital converter, in order to produce a data signal groups according to this oscillator signal; And
One digit-control resistance device is coupled to this feedback circuit, in order to this feedback signal that decays; Wherein this data signal groups is controlled the resistance value of capacitance and this digit-control resistance device of this numerical control capacitor.
7. control circuit as claimed in claim 6 is characterized in that, described this numerical control capacitor comprises:
Many group switch-capacitors are right, and those switch-capacitors are to being connected in parallel to each other, and wherein those switch-capacitors are to being that regulating switch and modulation capacitors by many groups of indivedual series connection are formed, and by opening and closing those regulating switch by this data signal groups.
8. control circuit as claimed in claim 6 is characterized in that, described this digit-control resistance device comprises:
Many group convert resistances are right, and those convert resistances are to being connected in parallel to each other, and wherein those convert resistances are to being that attenuator switch and damping resistance devices by many groups of indivedual series connection are formed, and by opening and closing those attenuator switch by this data signal groups.
9. control circuit as claimed in claim 6 is characterized in that, described this first oscillator comprises:
One charging current source is in order to produce a charging current;
One discharging current source is in order to produce a discharging current;
One oscillating capacitor is in parallel with this numerical control capacitor;
One charge switch is connected between this charging current source and this oscillating capacitor;
One discharge switch is connected between this discharging current source and this oscillating capacitor;
One first comparator, one first input is provided by one first reference voltage, and one second input is to be connected to this oscillating capacitor;
One second comparator, one first input is connected to this oscillating capacitor, and one second input is provided by one second reference voltage, and wherein this first reference voltage is to be higher than this second reference voltage;
One first lock is coupled to this commutation circuit, and in order to determine the switching frequency of this switching signal, wherein one first of this first lock input is an output that is coupled to this first comparator, and wherein one of this first lock output is in order to open and close this discharge switch; And
One second lock, its two inputs are connected to this output of this first lock and an output of this second comparator respectively, and an output of this second lock is one second input that is connected to this first lock, wherein one of this second lock output is in order to open and close this charge switch.
10. control circuit as claimed in claim 6 is characterized in that, described this analog-digital converter comprises:
A plurality of comparators, the positive input of those comparators is supplied by this oscillator signal, and the negative input of those comparators is supplied by many groups reference voltage of correspondence respectively;
A plurality of flip-flops, the input of those flip-flops is coupled to the output of those comparators respectively, and wherein the pulse of those flip-flops input is that output by this first oscillator is provided; And
One encoder is coupled to the output of those flip-flops, in order to produce this data signal groups.
11. the controller with frequency modulating in order to control a power supply changeover device, is characterized in that, this controller comprises:
One switches circuit, is coupled to a feedback circuit, switches signal to regulate an output of this power supply changeover device in order to produce one, and wherein this feedback circuit is this output that is coupled to this power supply changeover device, so that a feedback signal of this switching signal of control to be provided;
One first oscillator is coupled to this commutation circuit, in order to determine the switching frequency of this switching signal;
One numerical control capacitor is coupled to this first oscillator, in order to the switching frequency of this switching signal of modulation; And
One second oscillator, in order to produce an oscillator signal, wherein this second oscillator comprises a coding circuit, in order to produce a data signal groups according to this oscillator signal; Wherein this data signal groups is in order to control the capacitance of this numerical control capacitor.
12. control circuit as claimed in claim 11 is characterized in that, described this numerical control capacitor comprises:
Many group switch-capacitors are right, and those switch-capacitors are to being connected in parallel to each other, and wherein those switch-capacitors are to being that regulating switch and modulation capacitor by indivedual series connection formed, and by opening and closing those regulating switch by this data signal groups.
13. control circuit as claimed in claim 11 is characterized in that, described this coding circuit comprises:
A plurality of comparators, the positive input of those comparators is supplied by this oscillator signal, and the negative input of those comparators is then provided by many groups reference voltage of its correspondence respectively;
A plurality of flip-flops, the input of those flip-flops are the output that is coupled to those comparators respectively, and wherein the pulse of those flip-flops input is the output that is connected to this first oscillator; And
One encoder is coupled to the output of those flip-flops, in order to produce this data signal groups.
14. the controller with frequency modulating in order to control a power supply changeover device, is characterized in that, this controller comprises:
One switches circuit, is coupled to a feedback circuit, switches signal to regulate an output of this power supply changeover device in order to produce one, and wherein this feedback circuit is this output that is coupled to this power supply changeover device, so that a feedback signal of this switching signal of control to be provided;
One first oscillator is coupled to this commutation circuit, in order to determine the switching frequency of this switching signal;
One second oscillator is coupled to this first oscillator, in order to the switching frequency of this switching signal of modulation; And
One digit-control resistance device is coupled to this feedback circuit, in order to this feedback signal that decays; Wherein this second oscillator is coupled to this digit-control resistance device, to control the resistance value of this digit-control resistance device.
15. the control circuit with frequency modulating in order to control a power supply changeover device, is characterized in that, this control circuit comprises:
One switches circuit, is coupled to a feedback circuit, switches signal to regulate an output of this power supply changeover device in order to produce one, and wherein this feedback circuit is this output that is coupled to this power supply changeover device, so that a feedback signal of this switching signal of control to be provided;
One first oscillator is coupled to this commutation circuit, in order to determine the switching frequency of this switching signal; And
One second oscillator, in order to produce an oscillator signal, wherein this second oscillator comprises a coding circuit, in order to produce a data signal groups according to this oscillator signal; Wherein this data signal groups is to be coupled to this first oscillator, in order to the switching frequency of this switching signal of modulation.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNU2005201430639U CN2877127Y (en) | 2005-12-01 | 2005-12-01 | Control circuit with frequency modulation for decreasing electromagnetic interference of power converter |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNU2005201430639U CN2877127Y (en) | 2005-12-01 | 2005-12-01 | Control circuit with frequency modulation for decreasing electromagnetic interference of power converter |
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| Publication Number | Publication Date |
|---|---|
| CN2877127Y true CN2877127Y (en) | 2007-03-07 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNU2005201430639U Expired - Fee Related CN2877127Y (en) | 2005-12-01 | 2005-12-01 | Control circuit with frequency modulation for decreasing electromagnetic interference of power converter |
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| CN (1) | CN2877127Y (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107834822A (en) * | 2016-09-16 | 2018-03-23 | 电力集成公司 | Chattering frequency is modulated when switching frequency is close to chattering frequency |
| CN108173428A (en) * | 2018-01-08 | 2018-06-15 | 深圳市智行畅联科技有限公司 | A kind of DC-DC power source inhibit radiation dispersion it is exceeded tremble frequency circuit |
-
2005
- 2005-12-01 CN CNU2005201430639U patent/CN2877127Y/en not_active Expired - Fee Related
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107834822A (en) * | 2016-09-16 | 2018-03-23 | 电力集成公司 | Chattering frequency is modulated when switching frequency is close to chattering frequency |
| US11079778B2 (en) | 2016-09-16 | 2021-08-03 | Power Integrations, Inc. | Modulating jitter frequency as switching frequency approaches jitter frequency |
| CN107834822B (en) * | 2016-09-16 | 2021-11-16 | 电力集成公司 | Controller for switch mode power converter and power converter |
| US11487311B2 (en) | 2016-09-16 | 2022-11-01 | Power Integrations, Inc. | Modulating jitter frequency as switching frequency approaches jitter frequency |
| CN108173428A (en) * | 2018-01-08 | 2018-06-15 | 深圳市智行畅联科技有限公司 | A kind of DC-DC power source inhibit radiation dispersion it is exceeded tremble frequency circuit |
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