CN1933309A - Efficient voltage reducing switch - Google Patents
Efficient voltage reducing switch Download PDFInfo
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- CN1933309A CN1933309A CN 200510109605 CN200510109605A CN1933309A CN 1933309 A CN1933309 A CN 1933309A CN 200510109605 CN200510109605 CN 200510109605 CN 200510109605 A CN200510109605 A CN 200510109605A CN 1933309 A CN1933309 A CN 1933309A
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Abstract
This invention provides a high efficient voltage-dropping converter with power-saving structure, in which, a first circuit generates an oscillation signal and a power-saving signal based on a feedback signal, a second circuit generates multiple switch signals based on said feedback signal and said oscillation signal to control multiple switch devices, and the off time of the switch signal prolongs along the reduction of the load, said power saving signal cuts off part of control circuit of said switch device and the voltage dropping converter at the cut-off time of the switch signal to save power under light load.
Description
Technical field
The invention relates to a kind of step-down controller, suitching type adjuster and power converter.
Background technology
Step-down controller (Buck Converters) is widely used in computer, communication and the consumer products, in order to the accurate position of a high input voltage (as 12V) is converted to low voltage output (as 3.3V, 2.5V, 1.8V, 0.9V... etc.).Wherein PWM (pulse wave width modulation) switching is the major technique of power source conversion, and in addition, a synchronous commutation technique is in order to the efficient of improvement step-down controller under fully loaded transportation condition.
Fig. 1 shows a known step-down controller.One switch 20 is coupled to an input voltage V of this step-down controller
INThis input voltage of action military order V via this switch 20
INPower be converted to an output voltage V by an inductor 30
OA voltage divider that is made of resistor 51 and 52 is coupled to this output voltage V
OAnd between the ground connection reference edge.This voltage divider also provides one to be proportional to this output voltage V
OSignal V
FBGive a control circuit 10, according to this signal V
FB, signal S is switched in these control circuit 10 outputs one
W1, in order to the conduction and cut-off of controlling this switch 20 to reach the purpose of voltage-regulation.One diode 22 is coupled between this switch 20 and this ground connection reference edge, in order to the current cycle path of this inductor 30 when switch 20 ends to be provided.
Fig. 2 shows that one has the known step-down controller of synchronous rectification, and a switch 25 is as a synchronous rectifier, in order to reduce the power loss that pressure drop caused because of this diode 22 among first figure.Wherein this diode 22 among Fig. 1 can replace it by a parasitic diode 23 of the switch 25 among Fig. 2 or the Schottky diode that adds.One switches signal S
W2Logic level and this switch signal S
W1Oppositely, in order to conduction and cut-off switch 25.
Fig. 3 A to Fig. 3 D shows the synchronous rectification action of this step-down controller.With reference to Fig. 3 A, when these switch 20 conductings, when this switch 25 ends, this input voltage V
INTo supply an electric current I
CFlow to an output capacitance 40 by this inductor 30, to produce this output voltage V
OThe output of this step-down controller is to be provided by these output capacitance 40 two ends, and simultaneously, energy can be stored among inductor 30 and the capacitor 40.
Show that as Fig. 3 B when this switch 20 ended with this switch 25, stored energy will be supplied to the output of this step-down controller successively by the parasitic diode 23 of switch 25 in this inductor 30.Subsequently, shown in Fig. 3 C, just these switch 25 conductings are to lower the power loss of this parasitic diode 23.In next switching cycle once more before this switch 20 of conducting, can be earlier by this switch 25 to avoid taking place the short circuit that mutual conductance phenomenon (cross conduction) causes.Though synchronous rectification action can improve the efficient of this step-down controller under fully loaded transportation condition, but but can't overcome problem inefficient under the underloading condition, this problem is that the reverse electric discharge phenomena by this output capacitance 40 are caused.As shown in Figure 4, under the underloading condition, energy stored in this inductor 30 just will be discharged before next switching cycle begins fully.Therefore stored energy will be by inductor 30 and switch 25 reverse releases in this capacitor 40.
Moreover under the underloading condition, the main power loss of this step-down controller and this switch signal S
W1Switching frequency F be directly proportional the switch cost of the iron loss of this inductor 30 (core loss) and this switch 20 and 25 for example.The main power loss of another of this step-down controller then causes because of the power consumption of this control circuit 10.One switching period T is the inverse of this switching frequency F, and its equation is as follows:
T＝1/F＝(T
ON+T
OFF)
T wherein
ONWith T
OFFBe respectively and switch signal S
W1An ON time (on time) and a deadline (off time).
Prolong the loss of this switching cycle T cpable of lowering power.Yet, be the volume of reduced inductance device and capacitor, this switching frequency F must limitedly make its operate on extremely short switching cycle in.Saturated for avoiding inductor to take place, maximum ON time also must be restricted.Therefore, under the underloading condition, prolong T deadline
OFFCan prolong this switching cycle T.So, under underloading even unloaded condition, can utilize the prolongation of this switching cycle T and lower the power consumption of this step-down controller.
Summary of the invention
The object of the present invention is to provide a kind of step-down controller, be used to have high efficiency concurrently under weight, the underloading condition with province's electric components.
For achieving the above object, the step-down controller with province's electric components provided by the invention comprises:
One switching device shifter is coupled to an input of this step-down controller, is used for the output that power controlling is sent to this step-down controller;
One auxiliary switching device is connected to this switching device shifter and is used to carry out synchronous rectification;
One feedback circuit is coupled to this output of this step-down controller, is used for producing one in response to loading condition and feedbacks signal;
One first circuit, according to this back coupling signal to produce an oscillation signal and a power saving signal; And
One second circuit produces main signal and the secondary signal that switches of switching to control this switching device shifter and this auxiliary switching device respectively according to this back coupling signal and this oscillation signal; Wherein can and prolong along with load decline the deadline of this master's switching signal, and this power saving signal is ended part circuit and this switching device shifter of this step-down controller under the underloading condition.
This step-down controller, wherein before the switching frequency that this master is switched signal fell into voiced band, this main signal that switches was for stopping using, so that eliminate audio-frequency noise.
This step-down controller, wherein this first circuit comprises:
One modulator couples this back coupling signal, and produces a discharging current and a underloading signal according to this back coupling signal;
One oscillating circuit comprises a charging current source, a discharging current source, a charge switch, a discharge switch, a capacitor and an oscillation control circuit, in order to produce this oscillation signal; And
One power-saving circuit, be coupled to this oscillation signal and this underloading signal, in order to produce this power saving signal, wherein this discharging current can descend and descend along with load, the enabling time of this oscillation signal can prolong according to the decline of this discharging current, in case wherein load is lower than a critical value, this underloading signal just can be activated, and will enable this power saving signal when this underloading signal and this oscillation signal all are activated.
This step-down controller, wherein when this oscillation signal was activated, this master was switched signal and just can be ended and can change along with load variations its deadline, and the maximum ON time that this master is switched signal is a definite value, and is saturated to avoid magnet assembly to take place.
This step-down controller, wherein this modulator comprises:
One first operational amplifier is coupled to this back coupling signal;
One second operational amplifier is coupled to a reference voltage;
One voltage is to current converter, by a transistor AND gate one resistor-junction should first operational amplifier and this second operational amplifier constituted, this voltage produces one first electric current to current converter system, when this back coupling signal was lower than this reference voltage, this first electric current just can be feedback signal and descends and raise along with this;
One first current mirror receives this first electric current, in order to produce one second electric current;
One constant current source;
One second current mirror is coupled to this constant current source, and in order to produce one the 3rd electric current and one the 4th electric current, wherein this first current mirror couples by this second electric current and the 3rd electric current respectively mutually with this second current mirror;
One the 3rd current mirror, receive a difference electric current of this second electric current and the 3rd electric current, in order to produce one the 5th electric current, one the 6th electric current and one the 7th electric current, wherein this first current mirror couples by the 5th electric current and the 4th electric current respectively mutually with the 3rd current mirror;
One first switch has one first end and one second end, and this first end of this first switch is by the 6th electric current supply;
One second switch has one first end and one second end, and this of this second switch first end is by the 7th electric current supply, and this second end of this second switch produces this discharging current;
One buffer circuit, have an input and an output, this input of this buffer circuit is supplied by a difference electric current of the 5th electric current and the 4th electric current, this input of this buffer circuit also is connected to this second end of this first switch, and this output of this buffer circuit is in order to this first switch of conduction and cut-off and this second switch; And
One inverter has an input and an output, and this input of this inverter is connected to this output of this buffer circuit; This output of this inverter produces this underloading signal.
The present invention also provides an a kind of switching type voltage stabilizer with province's energy member, comprises:
One switching device shifter is coupled to an input of this switching type voltage stabilizer, is sent to an output of this suitching type adjuster in order to power controlling;
One feedback circuit is coupled to this output of this switching type voltage stabilizer, is used to produce one and feedbacks signal;
One first circuit, according to this back coupling signal to produce an oscillation signal; And
One second circuit produces one according to this back coupling signal and this oscillation signal and switches signal in order to control this switching device shifter; Wherein the switching frequency of this switching signal can along with this feedback signal variation and change, and can descend and prolong the deadline of this switching signal along with load, but the maximum ON time of this switching signal is a definite value, to avoid the magnet assembly generation saturated.
This switching type voltage stabilizer, wherein before this switching frequency of this switching signal fell into voiced band, this switching signal can be stopped using, so that eliminate audio-frequency noise.
This switching type voltage stabilizer, wherein this first circuit comprises:
One modulator couples this back coupling signal, and produces a discharging current according to this back coupling signal;
One oscillating circuit, comprise a charging current source, a discharging current source, a charge switch, a discharge switch, a capacitor and an oscillation control circuit, in order to produce this oscillation signal, wherein this discharging current can descend and descend along with load, and wherein the enabling time of this oscillation signal can prolong along with the decline of this discharging current.
This switching type voltage stabilizer, wherein when this oscillation signal was enabled, this switching signal just can end and can change the deadline of this switching signal along with load variations.
The present invention also provides a kind of power-saving control member, is used in power supply changeover device, comprises:
One feedback circuit, the output that it is coupled to this power supply changeover device is used for according to load variations to produce a back coupling signal;
One first circuit according to this back coupling signal, produces a power saving signal under the underloading condition; And
One second circuit produces one according to this back coupling signal and switches signal is sent to this power supply changeover device in order to power controlling load; Wherein this power saving signal can transmit by power, and closes the part circuit of this power supply changeover device.
This power-saving control member, wherein this first circuit comprises:
One modulator receives this back coupling signal and is used to produce a underloading signal;
One oscillating circuit comprises a charging current source, this discharging current source, a charge switch, a discharge switch, a capacitor and an oscillation control circuit, in order to produce this oscillation signal; And
One power-saving circuit receives this oscillation signal and this underloading signal, and in order to produce this power saving signal, in case wherein load is lower than a critical value, this underloading signal just can be activated, and can produce this power saving signal when this underloading signal and this oscillation signal all are activated just.
Description of drawings
Fig. 1 shows a known step-down controller.
Fig. 2 shows that one has the known step-down controller of synchronous rectification.
The synchronous rectification running of this known step-down controller of Fig. 3 A to Fig. 3 D displayed map 2.
Fig. 4 shows a back discharge phenomenon of this known step-down controller of Fig. 2 under the underloading condition.
Fig. 5 A shows the running of an efficient voltage reducing switch under fully loaded transportation condition.
Fig. 5 B shows the running of this efficient voltage reducing switch under the underloading condition.
Fig. 6 shows a control circuit calcspar of the step-down controller of the embodiment of the invention.
Fig. 7 shows the bias circuit according to this control circuit of the embodiment of the invention.
Fig. 8 shows a second circuit of this control circuit of the embodiment of the invention.
Fig. 9 shows a feedback circuit of this control circuit of the embodiment of the invention.
Figure 10 shows one first circuit of this control circuit of the embodiment of the invention.
Figure 11 shows a modulator schematic diagram of this first circuit of the embodiment of the invention.
Figure 12 shows the oscillogram of switching signal of the present invention.
Embodiment
With reference to figure 6, it shows the calcspar according to a control circuit 10 of the embodiment of the invention one step-down controller.It comprises a bias circuit 60, a feedback circuit 80, one first circuit 90 and a second circuit 70.This bias circuit 60 is bias current I of each circuit in this step-down controller of supply
0I
NOne is coupled between an output of this step-down controller and the ground connection reference edge in order to produce a signal V by resistor 51 and 52 voltage dividers that constituted
FBGive this feedback circuit 80, this signal V
FBOutput voltage V with this step-down controller
OProportional.This feedback circuit 80 is according to this signal V
FBProduce a back coupling signal V
B, in order to the expression loading condition.This first circuit 90 produces an oscillation signal PLS, a sawtooth waveforms signal V
SAW, a power saving signal V
G1An and assist control signal V
G2
With reference to figure 2 and Fig. 6, this second circuit 70 is according to this back coupling signal V
BProduce a main signal S that switches with this oscillation signal PLS
W1With a secondary signal S that switches
W2, so that control a switching device shifter 20 and a synchronous rectification switching device shifter 25.This switching device shifter 20 is coupled to an input voltage V
IN, be sent to the power of the output of this step-down controller in order to control.This main signal S that switches
W1One deadline T
OFFIncrease along with the reduction of load.At this main signal S that switches
W1This deadline of T
OFFDuring this time, this power saving signal V
G1Can be used to the part circuit in this step-down controller, in order to be issued to purpose of power saving in underloading.This main signal S that switches
W1Before falling into voiced band, its switching frequency will stop using, to avoid taking place audio-frequency noise.When the load increase, and make this master switch signal S
W1Switching frequency be higher than voiced band, this feedbacks signal V
BCan make this master switch signal S
W1Enable once more.In case should mainly switch signal S
W1This deadline of T
OFFBecause of load decline overtime, this assist control signal V
G2Just can will should pair switch signal S
W2Stop using, in order to end switching device shifter 25.So, show respectively as Fig. 5 A and Fig. 5 B institute, operation such as the same step-down controller with synchronous rectification of step-down controller of the present invention under fully loaded transportation condition, the operation under the underloading condition are then as same known step-down controller, so that improve the efficient of this step-down controller.
Fig. 7 is the preferred embodiment according to this bias circuit 60 of this control circuit 10 of the present invention.This bias circuit 60 produces bias current I
0I
NOne energy gap reference voltage circuit 110 can produce a reference voltage V
REF1With a reference voltage V
REF2This reference voltage V
REF1Be coupled to one first voltage to current converter, this first voltage is made of an operational amplifier 112, a resistor 113 and a transistor 114 current converter.This first voltage to current converter according to this reference voltage V
REF1To produce certain electric current I
114One one first current mirroring circuit that is made of transistor 115,116,117,118,119 is according to deciding electric current I
114Produce bias current I
0I
NThis bias current I
0I
NProvide power supply to each circuit in this step-down controller respectively.As shown in Fig. 7, switch 124,123 is used for respectively enabling and inactive bias current I
NWith I
N+1, to reach the power saving purpose.The conducting of switch 124,123 or by then being controlled by this power saving signal V
G1Therefore, this power saving signal V
G1The circuit that can in this step-down controller, under underloading, not operate.Fig. 8 is the schematic diagram of this second circuit 70 of preferred embodiment according to the present invention.This second circuit 70 comprises a flip-flop 78, and an input D of this flip-flop 78 is by a supply voltage V
CCInstitute provides, and the frequency input of this flip-flop 78 is provided by an anti-phase oscillations signal/PLS who is exported from inverter 71.One is coupled to an output, this anti-phase oscillations signal/PLS and this power saving signal V of flip-flop 78 with door 79 input
G1Should be connected to an output buffer with an output of door 79 and switch signal S in order to produce this master
W1The mutual conductance phenomenon takes place by constituting with door 140,145 and 130,135 of inverters in order to avoid switching device shifter 20 and 25 in this output buffer.Falling edge according to this oscillation signal PLS switches signal S to enable this master
W1Enable this oscillation signal PLS and this power saving signal V
G1This master's switching signal S can stop using
W1One input of one NOR gate 76 is coupled to this and door this output of 79.This pair is switched signal S
W2Then produce with this output buffer via this NOR gate 76.So this pair is switched signal S
W2Phase place and this main signal S that switches
W1On the contrary.Another input of this NOR gate 76 is by this assist control signal V
G2Supply.Therefore, when enabling assist control signal V
G2During with the saving power supply, just can switch signal S by this pair
W2
A multiple negative input with reference to figure 8, one comparators 72 is by this sawtooth waveforms signal V
SAWSupply.One positive input of this comparator 72 is then by this back coupling signal V
BSupply, in order to reach feedback loop control.One output of this comparator 72 be coupled to one with a door input of 73.Should then be coupled to a replacement input of this flip-flop 78 with an output of door 73.Should be coupled to an output of a protective circuit 75 with another input of door 73.This protective circuit 75 comprises overvoltage, overcurrent and over-temperature protection function, in order to protect this step-down controller and coupled circuit.Therefore, by this protective circuit 75 and this back coupling signal V
BJust can stop this master and switch signal S
W1Have an effect.
One bias current I
N+2With this bias current I
N+1Provide power supply to this protective circuit 75 and this comparator 72 respectively.Under the underloading condition, bias current I
N+1With I
N+2All can be deactivated, to end protective circuit 75 and comparator 72, in order to reduce power consumption to reach purpose of power saving.
Fig. 9 is these feedback circuit 80 schematic diagrames of this control circuit 10 of the preferred embodiment according to the present invention.This feedback circuit 80 comprises transduction (trans-conductance) error amplifier 81, and its positive input is by this reference voltage V
REF1Supply, its negative input is then by signal V
FBSupply.One resistor 82 and a capacitor 83 are coupled to an output of this error amplifier 81 to use as frequency compensation.Surely the gate of Bit Shift transistor 85 can be connected to this output of this transduction error amplifier 81; Its source electrode is connected to an attenuator of being made up of a resistor 86 and a resistor 87, in order to produce back coupling signal V
BBias current I
2With I
N+3Power supply is to this transduction error amplifier 81.Under the underloading condition, this bias current I
N+3For stopping using, in order to save the power consumption of error amplifier 81.
Figure 10 is these first circuit, 90 schematic diagrames of this control circuit 10 of the preferred embodiment according to the present invention.This first circuit 90 comprises a modulator 100, an oscillating circuit and a power-saving circuit, and it feedbacks signal V by this this modulator 100
BSupply, and feedback signal V according to this
BProduce a discharging current I
D, a underloading signal V
DWith an assist control signal V
G2This oscillating circuit comprises a charging current source 150, a discharging current source 160, a charge switch 153, a discharge switch 154, a capacitor 155 and an oscillation control circuit, in order to produce this oscillation signal PLS and this sawtooth waveforms signal V
SAWThis power-saving circuit is implemented by a NAND gate 167, and its two input is by this oscillation signal PLS and this underloading signal V
DSupply respectively is in order to produce this power saving signal V
G1First current mirror that this discharging current source is made up of transistor 151 and 152 is implemented, this discharging current I
DBe coupled to this oscillation control circuit by this first current mirroring circuit.This charge switch 153 is coupled between this charging current source 150 and this capacitor 155.This discharge switch 154 is connected between the output in this capacitor 155 and this discharging current source.This oscillation control circuit comprises one and has high critical voltage V
HComparator 161, have comparator 162, a NAND gate 163, a NAND gate 164 and the inverter 165 of low critical voltage VL.This comparator 162 and 163 all is connected to this capacitor 155.This comparator 161 and 162 output can be connected to by this NAND gate 163 and 164 latch circuits of being formed, in order to produce oscillation signal PLS.This discharge switch 154 is controlled its conducting by this oscillation signal PLS or is ended, and this discharge switch 153 is controlled by this oscillator signal PLS by this inverter 165.By alternately switching this charge switch 153 and this discharge switch 154, just can produce vibration.
When load reduces this discharging current I
DJust can reduce, the enabling time of oscillation signal PLS then can with increase.In case load subcritical value, underloading signal V
DJust enable.As this underloading signal V
DWhen enabling, just can produce this power saving signal V with this oscillation signal PLS
G1One charging current I of this charging current source
ADetermine this master to switch signal S with the capacitance of this capacitor 155
W1Maximum ON time T
ONThis discharging current I
DWith this main signal S that switches of these capacitor 155 decisions
W1One deadline T
OFFThis charging current I
ABe the certain value electric current, and this discharging current I
DThen can change along with the variation of load.
Figure 11 is these modulator 100 schematic diagrames of the preferred embodiment according to the present invention.This modulator 100 comprises an operational amplifier 182, and this operational amplifier 182 is by this back coupling signal V
BSupply.One operational amplifier 181 is by this reference voltage V
REF1Supply.One transistor 185 and a resistor 183 associative operation amplifiers 181 and 182 are formed one second voltage to current converter, in order to produce an electric current I
185In case should back coupling signal V
BBe lower than this reference voltage V
REF2, this electric current I
185Just can feedback signal V along with this
BMinimizing and increase.One second current mirroring circuit of being made up of transistor 186 and 187 receives this electric current I
185, in order to produce an electric current I
187Certain bias current I
1Be supplied to one the 3rd current mirroring circuit of being formed by transistor 188,189,190 and 196, in order to produce an electric current I respectively
189, an electric current I
190With an electric current I
196One drain of this transistor 187 is connected with a drain of this transistor 189.One the 4th current mirroring circuit of being made up of transistor 191,192,193,194 and 195 receives this electric current I
189With this electric current I
187A difference electric current, in order to produce an electric current I
192, an electric current I
193, an electric current I
194With an electric current I
195One drain of this transistor 192 is connected with a drain of this transistor 190.One drain of this transistor 193 is connected with a drain of this transistor 196.One input of one inverter buffer 207 is coupled to this drain of this transistor 193.One output of this inverter buffer 207 can produce assist control signal V
G2One first end of one switch 201 is coupled to this transistor 194 in order to receive an electric current I
194One second end of this switch 201 is coupled to an input of a buffer circuit 205.This electric current I
192With this electric current I
190Difference currents can be provided to the input of buffer circuit 205.One switch 202 is coupled to an electric current I
195In order to produce this discharging current I
DOne output of this buffer circuit 205 is controlled the conducting of this switch 201 and 202 or is ended.One inverter 206 is coupled to this output of this buffer circuit 205, in order to produce this underloading signal V
DThis underloading signal V
DCritical accurate position for adjustable to be used for eliminating audio-frequency noise.This discharging current I
DDetermine this master to switch signal S
W1Switching frequency.Switch signal S when this is main
W1Switching frequency when falling into voiced band, this switch 202 just can end, so that stop using this discharging current I
DSwitch signal S with this
W1, in order to eliminate audio-frequency noise.When the load increase, this back coupling signal V
BJust can this switch 202 of conducting so that enable this discharging current I once more
D, and make this master switch signal S
W1Switching frequency be higher than voiced band.
Figure 12 is according to the main signal S that switches of the present invention
W1Oscillogram.S wherein
W1 (F)Main switching signal under the expression fully loaded transportation condition, and S
W1 (L)The main signal that switches under the expression underloading condition.When this oscillation signal PLS is activated, this main signal S that switches
W1Just can be deactivated so that but T deadline of program to be provided
OFFThis main signal S that switches
W1Maximum ON time T
ONFor fixing, saturated to prevent that magnet assembly from taking place.
The above all only is embodiments of the invention, its purpose and non-limiting claim of the present invention; The personage who has the knack of present technique will be appreciated that all equivalences of being finished change or modification all should be included in the category of claim of the present invention under not breaking away from disclosed spirit.
Claims (11)
1, a kind of step-down controller with province's electric components comprises:
One switching device shifter is coupled to an input of this step-down controller, is used for the output that power controlling is sent to this step-down controller;
One auxiliary switching device is connected to this switching device shifter and is used to carry out synchronous rectification;
One feedback circuit is coupled to this output of this step-down controller, is used for producing one in response to loading condition and feedbacks signal;
One first circuit, according to this back coupling signal to produce an oscillation signal and a power saving signal; And
One second circuit produces main signal and the secondary signal that switches of switching to control this switching device shifter and this auxiliary switching device respectively according to this back coupling signal and this oscillation signal; Wherein can and prolong along with load decline the deadline of this master's switching signal, and this power saving signal is ended part circuit and this switching device shifter of this step-down controller under the underloading condition.
2, this step-down controller as claimed in claim 1, wherein before the switching frequency that this master is switched signal fell into voiced band, this main signal that switches was for stopping using, so that eliminate audio-frequency noise.
3, this step-down controller as claimed in claim 1, wherein this first circuit comprises:
One modulator couples this back coupling signal, and produces a discharging current and a underloading signal according to this back coupling signal;
One oscillating circuit comprises a charging current source, a discharging current source, a charge switch, a discharge switch, a capacitor and an oscillation control circuit, in order to produce this oscillation signal; And
One power-saving circuit, be coupled to this oscillation signal and this underloading signal, in order to produce this power saving signal, wherein this discharging current can descend and descend along with load, the enabling time of this oscillation signal can prolong according to the decline of this discharging current, in case wherein load is lower than a critical value, this underloading signal just can be activated, and will enable this power saving signal when this underloading signal and this oscillation signal all are activated.
4, this step-down controller as claimed in claim 1, wherein when this oscillation signal is activated, this master is switched signal and just can be ended and can change along with load variations its deadline, and the maximum ON time that this master is switched signal is a definite value, and is saturated to avoid magnet assembly to take place.
5, this step-down controller as claimed in claim 3, wherein this modulator comprises:
One first operational amplifier is coupled to this back coupling signal;
One second operational amplifier is coupled to a reference voltage;
One voltage is to current converter, by a transistor AND gate one resistor-junction should first operational amplifier and this second operational amplifier constituted, this voltage produces one first electric current to current converter system, when this back coupling signal was lower than this reference voltage, this first electric current just can be feedback signal and descends and raise along with this;
One first current mirror receives this first electric current, in order to produce one second electric current;
One constant current source;
One second current mirror is coupled to this constant current source, and in order to produce one the 3rd electric current and one the 4th electric current, wherein this first current mirror couples by this second electric current and the 3rd electric current respectively mutually with this second current mirror;
One the 3rd current mirror, receive a difference electric current of this second electric current and the 3rd electric current, in order to produce one the 5th electric current, one the 6th electric current and one the 7th electric current, wherein this first current mirror couples by the 5th electric current and the 4th electric current respectively mutually with the 3rd current mirror;
One first switch has one first end and one second end, and this first end of this first switch is by the 6th electric current supply;
One second switch has one first end and one second end, and this of this second switch first end is by the 7th electric current supply, and this second end of this second switch produces this discharging current;
One buffer circuit, have an input and an output, this input of this buffer circuit is supplied by a difference electric current of the 5th electric current and the 4th electric current, this input of this buffer circuit also is connected to this second end of this first switch, and this output of this buffer circuit is in order to this first switch of conduction and cut-off and this second switch; And
One inverter has an input and an output, and this input of this inverter is connected to this output of this buffer circuit; This output of this inverter produces this underloading signal.
6, an a kind of switching type voltage stabilizer with province's energy member comprises:
One switching device shifter is coupled to an input of this switching type voltage stabilizer, is sent to an output of this suitching type adjuster in order to power controlling;
One feedback circuit is coupled to this output of this switching type voltage stabilizer, is used to produce one and feedbacks signal;
One first circuit, according to this back coupling signal to produce an oscillation signal; And
One second circuit produces one according to this back coupling signal and this oscillation signal and switches signal in order to control this switching device shifter; Wherein the switching frequency of this switching signal can along with this feedback signal variation and change, and can descend and prolong the deadline of this switching signal along with load, but the maximum ON time of this switching signal is a definite value, to avoid the magnet assembly generation saturated.
7, this switching type voltage stabilizer as claimed in claim 6, wherein before this switching frequency of this switching signal fell into voiced band, this switching signal can be stopped using, so that eliminate audio-frequency noise.
8, this switching type voltage stabilizer as claimed in claim 6, wherein this first circuit comprises:
One modulator couples this back coupling signal, and produces a discharging current according to this back coupling signal;
One oscillating circuit, comprise a charging current source, a discharging current source, a charge switch, a discharge switch, a capacitor and an oscillation control circuit, in order to produce this oscillation signal, wherein this discharging current can descend and descend along with load, and wherein the enabling time of this oscillation signal can prolong along with the decline of this discharging current.
9, this switching type voltage stabilizer as claimed in claim 6, wherein when this oscillation signal was enabled, this switching signal just can end and can change the deadline of this switching signal along with load variations.
10, a kind of power-saving control member is used in power supply changeover device, comprises:
One feedback circuit, the output that it is coupled to this power supply changeover device is used for according to load variations to produce a back coupling signal;
One first circuit according to this back coupling signal, produces a power saving signal under the underloading condition; And
One second circuit produces one according to this back coupling signal and switches signal is sent to this power supply changeover device in order to power controlling load; Wherein this power saving signal can transmit by power, and closes the part circuit of this power supply changeover device.
11, as this power-saving control member of claim 10, wherein this first circuit comprises:
One modulator receives this back coupling signal and is used to produce a underloading signal;
One oscillating circuit comprises a charging current source, this discharging current source, a charge switch, a discharge switch, a capacitor and an oscillation control circuit, in order to produce this oscillation signal; And
One power-saving circuit receives this oscillation signal and this underloading signal, and in order to produce this power saving signal, in case wherein load is lower than a critical value, this underloading signal just can be activated, and can produce this power saving signal when this underloading signal and this oscillation signal all are activated just.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB2005101096055A CN100486087C (en) | 2005-09-15 | 2005-09-15 | Voltage reducing converter |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB2005101096055A CN100486087C (en) | 2005-09-15 | 2005-09-15 | Voltage reducing converter |
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| CN1933309A true CN1933309A (en) | 2007-03-21 |
| CN100486087C CN100486087C (en) | 2009-05-06 |
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101965676A (en) * | 2008-03-12 | 2011-02-02 | 索尼爱立信移动通讯有限公司 | Switch mode electric pressure converter with low current mode reaches the method for carrying out voltage transitions with low current mode |
| CN103376818A (en) * | 2012-04-28 | 2013-10-30 | 上海海尔集成电路有限公司 | Device used for converting voltage signals |
| CN105119468A (en) * | 2013-08-07 | 2015-12-02 | 台湾快捷国际股份有限公司 | Control circuit of power converter and method therefore |
| CN110557035A (en) * | 2018-05-31 | 2019-12-10 | 通嘉科技股份有限公司 | Synchronous rectifier applied to secondary side of power converter and operation method thereof |
| WO2023019608A1 (en) * | 2021-08-16 | 2023-02-23 | Tcl华星光电技术有限公司 | Driving circuit and display device |
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2005
- 2005-09-15 CN CNB2005101096055A patent/CN100486087C/en active Active
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101965676A (en) * | 2008-03-12 | 2011-02-02 | 索尼爱立信移动通讯有限公司 | Switch mode electric pressure converter with low current mode reaches the method for carrying out voltage transitions with low current mode |
| CN101965676B (en) * | 2008-03-12 | 2013-11-06 | 索尼爱立信移动通讯有限公司 | Switched mode voltage converter with low-current mode and methods of performing voltage conversion with low-current mode |
| CN103376818A (en) * | 2012-04-28 | 2013-10-30 | 上海海尔集成电路有限公司 | Device used for converting voltage signals |
| CN103376818B (en) * | 2012-04-28 | 2015-03-25 | 上海海尔集成电路有限公司 | Device used for converting voltage signals |
| CN105119468A (en) * | 2013-08-07 | 2015-12-02 | 台湾快捷国际股份有限公司 | Control circuit of power converter and method therefore |
| CN105119468B (en) * | 2013-08-07 | 2018-01-16 | 台湾快捷国际股份有限公司 | The control circuit and its method of power converter |
| CN110557035A (en) * | 2018-05-31 | 2019-12-10 | 通嘉科技股份有限公司 | Synchronous rectifier applied to secondary side of power converter and operation method thereof |
| WO2023019608A1 (en) * | 2021-08-16 | 2023-02-23 | Tcl华星光电技术有限公司 | Driving circuit and display device |
Also Published As
| Publication number | Publication date |
|---|---|
| CN100486087C (en) | 2009-05-06 |
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