CN105720814B - Power converter, voltage adjusting unit and voltage adjusting method - Google Patents
Power converter, voltage adjusting unit and voltage adjusting method Download PDFInfo
- Publication number
- CN105720814B CN105720814B CN201410712489.5A CN201410712489A CN105720814B CN 105720814 B CN105720814 B CN 105720814B CN 201410712489 A CN201410712489 A CN 201410712489A CN 105720814 B CN105720814 B CN 105720814B
- Authority
- CN
- China
- Prior art keywords
- mentioned
- voltage
- current
- current sensing
- revolution rate
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000000034 method Methods 0.000 title claims description 25
- 230000000052 comparative effect Effects 0.000 claims description 28
- 230000005611 electricity Effects 0.000 claims description 20
- 235000013399 edible fruits Nutrition 0.000 claims description 2
- 230000001939 inductive effect Effects 0.000 description 21
- 238000010168 coupling process Methods 0.000 description 11
- 238000005859 coupling reaction Methods 0.000 description 11
- 230000008878 coupling Effects 0.000 description 10
- 238000010586 diagram Methods 0.000 description 10
- 230000000694 effects Effects 0.000 description 4
- 208000027418 Wounds and injury Diseases 0.000 description 3
- 230000006378 damage Effects 0.000 description 3
- 208000014674 injury Diseases 0.000 description 3
- 230000001960 triggered effect Effects 0.000 description 3
- 241000208340 Araliaceae Species 0.000 description 2
- 235000005035 Panax pseudoginseng ssp. pseudoginseng Nutrition 0.000 description 2
- 235000003140 Panax quinquefolius Nutrition 0.000 description 2
- 235000008434 ginseng Nutrition 0.000 description 2
- 230000003321 amplification Effects 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000003199 nucleic acid amplification method Methods 0.000 description 1
- 241000894007 species Species 0.000 description 1
- 230000026683 transduction Effects 0.000 description 1
- 238000010361 transduction Methods 0.000 description 1
Landscapes
- Dc-Dc Converters (AREA)
Abstract
A power converter includes a current sensing unit, a voltage adjusting unit and a pulse width modulation control unit. The current sensing unit is used for sensing the output current of the power converter to provide a current sensing signal. The voltage adjusting unit is coupled to the current sensing unit. The voltage adjusting unit provides a reference voltage according to the first slew rate and compares the current sensing signal with a preset reference value. When the comparison result of the voltage adjusting unit is that the current sensing signal is higher than the preset reference value, the voltage adjusting unit provides the reference voltage according to a second rotation rate, wherein the second rotation rate is lower than the first rotation rate. The PWM control unit is coupled to the voltage adjustment unit for receiving the reference voltage and controlling the power converter to provide the output voltage according to the reference voltage.
Description
Technical field
The present invention is relevant with power supply changeover device, has the automatic modulation work(of revolution rate (slew rate) especially with regard to one kind
Power supply changeover device, voltage-adjusting unit and the voltage adjusting method of energy.
Background technology
The system side of DC-to-dc suitching type reduction voltage circuit (Buck DC-DC Converter IC) known to Fig. 1 diagrams
Block figure.The output voltage Vout of DC-to-dc suitching type reduction voltage circuit 1 can be locked to a particular voltage level, and this is specific
Magnitude of voltage is determined by the magnitude of voltage of the reference voltage EAP received by error amplifier 121.
When system is just started shooting, the ginseng received by error amplifier 121 in DC-to-dc suitching type reduction voltage circuit 1
It can't be target voltage values (VID) at once to examine voltage EAP, but first can slowly rise to target voltage values from zero, and this is one dynamic
Make to be referred to as soft start (soft start).System needs to use the reasons why soft start is to start shooting to be：Assuming that when system is just started shooting
The output voltage Vout of DC-to-dc suitching type reduction voltage circuit 1 is zero, if the now reference received by error amplifier 121
Voltage EAP and non-zero, but of a relatively high target voltage values (VID), system must just make great efforts to charge to output capacitance Cout,
To enable output voltage Vout rapidly to reach target voltage values, its result is exactly the inductance electricity for causing to flow through outputting inductance L
Stream IL is excessive and produces serious surge current (in-rush current), is likely to result in outputting inductance L and burns or triggered
The situation of current protection (Over Current Protection, OCP) occurs.For the foregoing reasons, usual error amplifier
Voltage EAP received by 121 need to slowly rise to target voltage values (VID), and system also can be slowly to output voltage Vout
Target voltage values are charged to, to avoid causing system injury.
In general, system is defined as revolution rate in start to the speed speed of output capacitance Cout discharge and recharges
(slew rate).Once target voltage values (VID) have changed, (high to output capacitance Cout quick charges using upper and requirement
Revolution rate) when, very big surge current will be suffered from.If taken out heavily loaded (heavy load) to output at the same time again, electricity
Inducing current IL may touch the level of overcurrent protection and trigger overcurrent protection.
On the other hand, if output is short circuit, inductive current IL also can touch the level of overcurrent protection and trigger electricity
Stream protection.A problem is now suffered from, system needs successfully start shooting without touching in the case of high revolution rate and heavy duty
Overcurrent protection is sent out, if but in the case of short circuit start, system can correctly trigger overcurrent protection without starting shooting again.
The content of the invention
In view of this, the present invention provides a kind of power supply changeover device, voltage-adjusting unit and voltage adjusting method, thus solves
The problem of prior art is addressed.
A specific embodiment according to the present invention is a kind of power supply changeover device.In this embodiment, power supply changeover device includes
Current sensing unit, voltage-adjusting unit and PWM control unit.Current sensing unit is sensing power supply changeover device
Output current, to provide current sensing signal.Voltage-adjusting unit couples current sensing unit.Voltage-adjusting unit is according to first
Revolution rate provides reference voltage and compares current sensing signal and preset reference value.When current sensing signal is higher than preset reference value
When, voltage-adjusting unit changes provides reference voltage according to the second revolution rate, wherein the second revolution rate is less than the first revolution rate.Pulsewidth
Modulation control unit couples voltage-adjusting unit.PWM control unit receives reference voltage and controls electricity according to reference voltage
Source converter provides output voltage.
In one embodiment of the invention, voltage-adjusting unit includes comparator and voltage generating unit.Comparator couples
Current sensing unit.Comparator receives current sensing signal from current sensing unit and compares current sensing signal and preset reference
Value.Voltage generating unit couples comparator.Voltage generating unit provides reference voltage according to the first revolution rate.When the ratio of comparator
When relatively result is that current sensing signal is higher than preset reference value, voltage generating unit provides reference voltage according to the second revolution rate.
In one embodiment of the invention, voltage generating unit includes electric capacity and charging circuit.Charging circuit coupling is compared
Device and electric capacity.Charging circuit has multiple current sources.Charging circuit switches in multiple current sources according to the comparative result of comparator
Different current sources electric capacity is charged, the different current sources in plurality of current source provide different size of electric current respectively.
In one embodiment of the invention, when voltage generating unit provides reference voltage according to the first revolution rate, charging
Circuit is charged with the first current source in multiple current sources to electric capacity.When the comparative result of comparator is higher than for current sensing signal
During preset reference value, charging circuit is switched to the second current source in multiple current sources to electricity according to the comparative result of comparator
Capacity charge so that voltage generating unit changes provides reference voltage according to the second relatively low revolution rate, what the second current source was provided
Second electric current is less than the first electric current that the first current source is provided.
A specific embodiment according to the present invention is a kind of voltage-adjusting unit.In this embodiment, voltage-adjusting unit
Couple the current sensing unit of power supply changeover device.Voltage-adjusting unit includes comparator and voltage generating unit.Comparator couples
Current sensing unit.Comparator receives current sensing signal from current sensing unit and compares current sensing signal and preset reference
Value.Voltage generating unit couples comparator.Voltage generating unit provides reference voltage according to the first revolution rate.When the ratio of comparator
When relatively result is that current sensing signal is higher than preset reference value, voltage generating unit changes according to the second revolution rate to provide with reference to electricity
Pressure, wherein the second revolution rate is less than the first revolution rate.
In one embodiment of the invention, the current sensing unit senses an output current of the power supply changeover device to provide
The current sensing signal.
In one embodiment of the invention, the voltage generating unit includes：One electric capacity；And a charging circuit, coupling should
Comparator and the electric capacity, the charging circuit have multiple current sources, and the charging circuit switches according to the comparative result of the comparator
Different current sources in those current sources charge to the electric capacity, and wherein the different current sources in those current sources provide difference respectively
The electric current of size.
In one embodiment of the invention, when the voltage generating unit provides the reference voltage according to the first revolution rate
When, the charging circuit is charged with one first current source in those current sources to the electric capacity, when the comparative result of the comparator is
When the current sensing signal is higher than the preset reference value, the charging circuit is switched to those according to the comparative result of the comparator
One second current source in current source charges to the electric capacity so that the voltage generating unit changes according to relatively low the second revolution rate
The reference voltage is provided, one second electric current that second current source is provided is less than one first electricity that first current source is provided
Stream.
Another specific embodiment according to the present invention is a kind of voltage adjusting method.In this embodiment, voltage adjustment side
Method is applied to power supply changeover device.Voltage adjusting method comprises the following steps：(a) reference voltage is provided according to the first revolution rate；(b)
Current sensing signal is received from power supply changeover device and compares current sensing signal and preset reference value；And if (c) step (b)
Comparative result is that current sensing signal is higher than preset reference value, changes and provides reference voltage according to the second revolution rate, wherein second time
Rate of rotation is less than the first revolution rate.
In one embodiment of the invention, the current sensing signal is to sense an output current of the power supply changeover device and produce
It is raw.
In one embodiment of the invention, step (a) is that one electric capacity is filled with one first current source in multiple current sources
Electricity, during providing the reference voltage according to the first revolution rate, when the comparative result of step (b) is higher than for the current sensing signal
During the preset reference value, step (c) is switched to one second current source in those current sources according to the comparative result of step (b)
To the electric capacity charge, provide the reference voltage according to relatively low the second revolution rate to change, second current source provided one
Second electric current is less than one first electric current that first current source is provided.
In summary, can according to power supply changeover device provided by the present invention, voltage-adjusting unit and voltage adjusting method
Reached simultaneously by way of the automatic modulation of revolution rate and successfully started shooting in the case of high revolution rate and heavy duty without triggering electricity
Protection is flowed, and overcurrent protection is triggered without specific effects such as starts in the case where short circuit is started shooting, therefore can not only effectively be kept away
The situation that exempting from excessive surge current in the case of high revolution rate and heavy duty causes outputting inductance to burn occurs, and also can ensure that
In the case of short circuit start, overcurrent protection can be actuated to avoid causing system injury.
It can be further understood on advantages of the present invention and spirit by following detailed description of the invention and accompanying drawing.
Brief description of the drawings
The circuit diagram of DC-DC converter known to Fig. 1 diagrams.
Fig. 2 illustrates the circuit diagram of the power supply changeover device according to one embodiment of the invention.
Sensing voltage corresponding to Fig. 3 diagram inductive currents coordinates the different switch on condition of light/heavy duty in high/low revolution rate
The lower graph of a relation with the first level and the second level.
Fig. 4 is illustrated under the switch on condition that high revolution rate coordinates underloading, and the sensing voltage corresponding to inductive current will not touch
And first level, therefore the schematic diagram that its revolution rate remains unchanged.
Fig. 5 is illustrated under the switch on condition that high revolution rate coordinates heavy duty, and the sensing voltage corresponding to inductive current touches the
One level and force to reduce the schematic diagram of its revolution rate.
One embodiment of the adjustment unit in Fig. 6 diagram power supply changeover devices.
Fig. 7 illustrates the flow chart of the voltage adjusting method of the another specific embodiment according to the present invention.
Main element symbol description：
1：DC-to-dc suitching type reduction voltage circuit
2：Power supply changeover device
110、21：Output stage
120、22：PWM control unit
121、221：Error amplifier
122、222：Comparator
123、223：Time signal generator
124、224：Driver
23：Voltage-adjusting unit
24：Protection location
25：Current sensing unit
229：Compensating unit
TON：ON time signal
R：Resistance
C：Electric capacity
L：Outputting inductance
SW1：First switch
SW2：Second switch
ESR：Output resistance
Cout：Output capacitance
Vin：Input voltage
Vout：Output voltage
IL：Inductive current
Iload：Load current
EAP：Reference voltage
ERR：Error signal
ramp：Ramp signal
VFB：Feedback voltage
TT：Trigger signal
CS：Current sensing signal
UG、LG：Control signal
PHA：Phase node
Vrush：First level
+：Positive input terminal (first input end)
-：Negative input end (the second input)
Voc：Second level
Vimon：Corresponding to the sensing voltage of inductive current
230：Comparator
231：Revolution rate logic control element
232：Revolution rate adjustment unit
233：Error amplifier
NC：Normal revolution rate control signal
AD：Adjust signal
Ifast、Islow：Current source
Vsr：Revolution rate voltage
VH：High voltage
t：Time
Embodiment
Now with detailed reference to the one exemplary embodiment of the present invention, and illustrate the reality of the one exemplary embodiment in the accompanying drawings
Example.In addition, element/component of the same or like label used in schema and embodiment is same or like for representing
Part.
In following all embodiments, when element is regarded as being "connected" or "coupled" to another element, it can be directly to connect
Another element is connect or be coupled to, or there may be intervenient element.Term " circuit " is represented by an at least element or more
Individual element, or the element being coupled together on one's own initiative and/or passively is to provide proper function.Term " signal " can represent
It is an at least electric current, voltage, load, temperature, data or other signals.Ramp signal can be class ramp signal, triangular wave letter again
Number or sawtooth signal, it can be the oblique wave of repetition-decline form or the oblique wave of repetition-rising form, end regard application and
Determine.
A preferred embodiment according to the present invention is a kind of power supply changeover device.In this embodiment, the present invention proposes
Power supply changeover device can be DC-to-dc suitching type reduction voltage circuit (Buck applied to power IC (Power IC)
DC-DC Converter circuit) in, but be not limited.
It should be noted that power supply changeover device of the invention has the function of the automatic modulation of revolution rate (slew rate).As for
The size of revolution rate refers to speed of the power supply changeover device to the charging rate of its output capacitance, wherein when power supply changeover device is to it
The charging rate of output capacitance accelerates, and the revolution rate for representing power supply changeover device becomes big；Conversely, when power supply changeover device exports electricity to it
The charging rate of appearance is slack-off, and the revolution rate for representing power supply changeover device diminishes.
Fig. 2 is refer to, Fig. 2 illustrates the circuit diagram of the power supply changeover device according to one embodiment of the invention.Such as Fig. 2 institutes
Show, power supply changeover device 2 includes output stage 21, PWM control unit 22, voltage-adjusting unit 23, protection location 24 and electric current
Sensing unit 25.In this embodiment, PWM control unit 22 includes error amplifier 221, comparator 222, time letter
Number generator 223, driver 224 and compensating unit 229.Output stage 21 includes first switch SW1 and second switch SW2；First
Switch SW1 is also referred to as switch on the bridge, and second switch SW2 is also referred to as bridge switch.In other embodiment, output stage 21 is also
A switch, and the element such as diode of arranging in pairs or groups can only be included, be not limited thereto.
First switch SW1 coupling input voltage vins and driver 224 in output stage 21.Second in output stage 21 opens
Close SW2 coupling drivers 224 and earth terminal.Driver 224 respectively by control signal UG and LG come control first switch SW1 and
Second switch SW2's is turned on and off.A phase node PHA between first switch SW1 and second switch SW2 also be present, this
Phase node PHA coupling outputting inductances L one end.In this embodiment, phase node PHA is also coupled to driver 224.In other
In embodiment, phase node PHA also can not coupling drivers 224, be not limited thereto.
The negative input end of the error amplifier 221 of the PWM control unit 22-coupling outputting inductance L other end, with
A feedback voltage VFB is received from the outputting inductance L other end.In other embodiment, the negative input end of error amplifier 221-
Also the outputting inductance L other end can be coupled to by a partial pressure unit, is not limited thereto.In addition, error amplifier 221
First input end (such as：Positive input terminal+) coupling voltage-adjusting unit 23, the reference provided with receiving voltage adjustment unit 23
Voltage EAP.It has been observed that when system is just started shooting, the reference voltage received by error amplifier 221 in power supply changeover device 2
EAP can't be target voltage values VID at once, but first can slowly rise to target voltage values VID from zero, i.e. referred to as soft start
(soft start)。
In this embodiment, error amplifier 221 provides the error signal ERR with voltage pattern, in other embodiment
In, error amplifier 221 can also be substituted by transduction amplifier (GM), to provide the error signal ERR with electric current pattern, and
It is not limited.
The output end of the first input end coupling error amplifier 221 of comparator 222, in this embodiment, error amplification
The error signal ERR that device 221 is exported just can be by the first of comparator 222 after first passing through the compensation deals of compensating unit 229
Input is received.Comparator 222 the second input (such as：Negative input end -) then receiving ramp signal ramp.Than
Error signal ERR and ramp signal ramp can be compared compared with device 222, and according to error signal ERR and ramp signal ramp
Comparative result provide trigger signal TT to time signal generator 223.Time signal generator 223 is respectively coupled to comparator
222 and driver 224.Time signal generator 223 provides ON time signal TON to driving according to above-mentioned trigger signal TT
Device 224, driver 224 provide control signal UG and LG to control first in output stage 21 to open according to ON time signal TON
Close being turned on and off for SW1 and second switch SW2.Therefore, the coupling of said elements/circuit, PWM control unit are passed through
22 can couple output stage 21 and control the operation of output stage 21.
In one embodiment of the invention, current sensing unit 25 to sense an output current of power supply changeover device 2, with
Current sensing signal CS is provided to voltage-adjusting unit 23.It should be noted that the power supply that current sensing unit 25 is sensed turns
The output current of parallel operation 2 can flow through outputting inductance L inductive current IL, but be not limited.
In fact, current sensing unit 25 can also pass through DC impedance current sense (DCR current sensing)
Mode senses the output current of power supply changeover device 2 or is by second switch (lower bridge electric crystal) SW2 or phase node PHA
To sense the output current of power supply changeover device 2, specific limitation is had no.
When voltage-adjusting unit 23 receives current sensing signal CS from current sensing unit 25, voltage-adjusting unit 23
Current sensing signal CS and a preset reference value can first be compared, and according to current sensing signal CS and the comparison knot of preset reference value
Fruit is provided to the reference voltage EAP of the first input end of error amplifier 221, to control the institute of error amplifier 221 to adjust it
The error signal ERR of offer, thus change power supply changeover device 2 to output capacitance Cout charging rate speed (that is, revolution rate
Size).
In an embodiment, preset reference value can be a voltage level (such as first level Vrush in Fig. 3) and electricity
Stream sensing signal CS can be the sensing voltage for being relevant to inductive current IL, but be not limited.In fact, above-mentioned sensing electricity
Pressure can be voltage corresponding to inductive current IL, can by DC impedance current sense (DCR current sensing) or
The mode of low side current sensing (Low side current sensing) goes to sense the electric current stream that inductive current IL produces direct ratio
Above-mentioned sensing voltage is produced through resistance.
It can then compare current sensing signal CS (such as inductive currents as the protection location 24 of coupling voltage-adjusting unit 23
Sensing voltage corresponding to IL) and overcurrent protection level.If the comparative result obtained by protection location 24 is inductive current IL
Corresponding sensing voltage is more than overcurrent protection level, represents the output of power supply changeover device 2 to be short-circuit, protection location 24 is meeting
The overcurrent protection of startup power supply converter 2 is without starting shooting.
For example, as shown in Figure 3, it is assumed that the quasi- Voc of second is an overcurrent protection level, and preset reference value (
One level) Vrush is between 0 and overcurrent protection level (the second level) Voc, that is, the first level Vrush is less than second
Level Voc.Once inductive current IL is excessive, sensing voltage corresponding to it is caused to increase to over preset reference value (the first level)
Vrush and when touching overcurrent protection level (the second level) Voc, protection location 24 be can startup power supply converter 2 it is excessively electric
Stream protection is without starting shooting.
It should be noted that preset reference value (the first level) Vrush can be a surge current (in-rush current)
Level.As shown in figure 4, in the case where normal high revolution rate coordinates underloading (or no-load), inductive current IL is not big enough, because of it
Corresponding sensing voltage Vimon can not touch the first level Vrush, therefore its revolution rate remains unchanged.Only when high revolution rate
In the case of coordinating heavy duty, as shown in figure 5, when time t, when inductive current IL is larger, corresponding to inductive current IL
Sensing voltage Vimon can just be increased to touch the first level Vrush.Now, voltage-adjusting unit 23 one can compare according to this
As a result forced revolving rate step-down (that is, rate of voltage rise is slack-off, and the rate of rise diminishes), that is, power supply changeover device 2 is reduced to defeated
Go out electric capacity Cout charging rate so that inductive current IL diminishes, and causes the sensing voltage Vimon corresponding to it also to drop therewith
It is low.Thus, in the case that high revolution rate coordinates heavy duty, the sensing voltage Vimon corresponding to inductive current IL also will not
Touch overcurrent protection level (second level) Voc higher than preset reference value (the first level) Vrush, therefore power supply changeover device
2 will not start overcurrent protection.
One embodiment of the voltage-adjusting unit 23 in Fig. 6 diagram power supply changeover devices 2.As shown in fig. 6, comparator 230
Two inputs receive preset reference value (the first level) Vrush and current sensing signal CS respectively, and (such as inductive current IL institute is right
The sensing voltage Vimon answered) and compare the first level Vrush with sensing voltage Vimon.If the comparison obtained by comparator 230
As a result it is more than or equal to the first level Vrush for sensing voltage Vimon, represents sensing voltage Vimon and touched the first level
Vrush, then comparator 230 can send an adjustment signal AD to revolution rate logic control element 231.Under normal circumstances, turn round
The script of rate logic control element 231 is that had just to provide according to the normal revolution rate control signal NC of the processor from system
The revolution rate voltage Vsr of normal revolution rate.When revolution rate logic control element 231 receives the adjustment signal from comparator 230
During AD, revolution rate logic control element 231 can adjust the revolution rate voltage Vsr of its offer revolution rate according to adjustment signal AD
Size.
Voltage generating unit 232 includes electric capacity C and the charging circuit being made up of multiple current source Ifast and Islow.Electricity
Stream source Ifast and Islow is coupled back to rate of rotation logic control element 231 and electric capacity C, to provide different size of electric current pair respectively
Electric capacity C charges.Voltage generating unit 232 can switch different current source Ifast or Islow according to the comparative result of comparator 230
Electric capacity C is charged.In fact, the charging circuit to be charged to electric capacity C in voltage generating unit 232 also may include three or
More can provide the current source of different size of current, and its species and number are not limited with this example.
In Fig. 6 example, revolution rate logic control element 231 is by switching having not in voltage generating unit 232
Mode with the current source Ifast and Islow of size of current charges to electric capacity C and produces the revolution with different revolution rate sizes
Rate voltage Vsr.Change because reference voltage EAP can follow revolution rate voltage Vsr, therefore reference voltage EAP can also change therewith.
Thus, voltage-adjusting unit 23 can be by way of changing reference voltage EAP come alignment error signal ERR, to change power supply
Converter 2 is to output capacitance Cout charging rate, and then the effect of adjust revolution rate.
In practical application, revolution rate logic control element 231 provides the revolution rate voltage with different revolution rate sizes
Mode be not limited to Fig. 6 embodiment.In another embodiment, revolution rate logic control element 231 can also use clock pulse
Signal control counter is counted provides different size of voltage to produce to switch the mode of the different switches in multiplexer
Revolution rate voltage with different revolution rate sizes, but be also not limited.
Another specific embodiment according to the present invention is a kind of voltage adjusting method.In this embodiment, voltage adjustment side
Method is applied to power supply changeover device, to adjust a reference voltage of power supply changeover device.Fig. 7 is refer to, Fig. 7 illustrates this embodiment
The flow chart of voltage adjusting method.
As shown in fig. 7, in step S10, this method provides a reference voltage according to one first revolution rate.In fact, work as
When power supply changeover device is started shooting, the reference voltage that this method is provided is to be gradually increased to a target voltage values by zero, that is, soft is opened
It is dynamic.
In step S12, this method receives current sensing signal from power supply changeover device and compares current sensing signal with protecting
Level is protected, to judge current sensing signal whether higher than protection level.In fact, current sensing signal is sensing power supply changeover device
Output current and produce, it can be the sensing voltage for being relevant to inductive current, will definitely be to be one excessively electric as guard bit
Stream protection level (such as second level Voc in Fig. 3), but be not limited.
If step S12 comparative result is current sensing signal higher than protection level, represent the output of power supply changeover device as
Short circuit, this method perform step S14, thus the overcurrent protection of startup power supply converter avoids power supply changeover device without starting shooting
Damaged by overcurrent.
If step S12 comparative result is current sensing signal performs step S16 not higher than protection level, this method, than
Compared with current sensing signal and preset reference value, to judge whether current sensing signal is higher than preset reference value.In fact, default ginseng
It can be a voltage level (such as first level Vrush in Fig. 3) to examine value, and preset reference value can be less than protection level
(such as second level Voc in Fig. 3), but be not limited.
If step S16 comparative result, which is current sensing signal, is higher than preset reference value, this method performs step S18, changed
Reference voltage is provided according to the second revolution rate, wherein the second revolution rate is less than the first revolution rate.If step S16 comparative result is
Current sensing signal performs step S20 not higher than preset reference value, this method, continues according to the first revolution rate and provides reference voltage
It is constant.
It should be noted that step S10 is that electric capacity is charged with the first current source in multiple current sources, with according to first time
Rate of rotation provides reference voltage.When step S16 comparative result is higher than preset reference value for current sensing signal, step S18 roots
Switch to according to step S16 comparative result and electric capacity is charged with the second current source in multiple current sources, to change according to relatively low
Second revolution rate provides reference voltage, wherein the second electric current that the second current source is provided can be provided less than the first current source
First electric current.Thus, the voltage adjusting method applied to power supply changeover device can be supplied to the reference of error amplifier by changing
The mode of voltage is carried out alignment error amplifier and exported to the error signal of comparator, and then changes power supply changeover device to output capacitance
Charging rate speed, with reach adjustment power supply changeover device revolution rate specific effect.
In summary, it is logical according to power supply changeover device provided by the present invention, voltage-adjusting unit and voltage adjusting method
Cross the mode of the automatic modulation of revolution rate while reach and successfully started shooting in the case of high revolution rate and heavy duty without triggering overcurrent
Protection, and the effect of overcurrent protection is without starting shooting is triggered in the case where short circuit is started shooting, therefore can not only effectively avoid
The situation that excessive surge current causes outputting inductance to burn in the case of high revolution rate and heavy duty occurs, and also can ensure that in short circuit
In the case of start, overcurrent protection can be actuated to avoid causing system injury.
By the above detailed description of preferred embodiments, it is intended to more clearly describe the feature of the present invention with spiritual,
And not scope of the invention is any limitation as with above-mentioned disclosed preferred embodiment.On the contrary, the purpose is to uncommon
Various changes can be covered and have being arranged in the category of the claim to be applied of the invention of equality by hoping.
Claims (11)
1. a kind of power supply changeover device, it is characterised in that above-mentioned power supply changeover device includes：
One current sensing unit, to sense an output current of above-mentioned power supply changeover device, to provide a current sensing signal；
One voltage-adjusting unit, couples above-mentioned current sensing unit, and above-mentioned voltage-adjusting unit provides according to one first revolution rate
One reference voltage and more above-mentioned current sensing signal and a preset reference value, when above-mentioned current sensing signal is default higher than above-mentioned
During reference value, above-mentioned voltage-adjusting unit changes provides above-mentioned reference voltage according to one second revolution rate, wherein above-mentioned second revolution
Rate is less than above-mentioned first revolution rate；And
One PWM control unit, couples above-mentioned voltage-adjusting unit, and above-mentioned PWM control unit receives above-mentioned reference
Voltage simultaneously controls above-mentioned power supply changeover device to provide an output voltage according to above-mentioned reference voltage.
2. the power supply changeover device as described in claim 1, it is characterised in that above-mentioned voltage-adjusting unit includes：
One comparator, couples above-mentioned current sensing unit, and above-mentioned comparator receives above-mentioned electric current sense from above-mentioned current sensing unit
Survey signal and more above-mentioned current sensing signal and above-mentioned preset reference value；And
One voltage generating unit, couples above-mentioned comparator, and above-mentioned voltage generating unit provides above-mentioned according to above-mentioned first revolution rate
Reference voltage, when the comparative result of above-mentioned comparator is higher than above-mentioned preset reference value for above-mentioned current sensing signal, above-mentioned electricity
Generation unit is pressed to provide above-mentioned reference voltage according to above-mentioned second revolution rate.
3. power supply changeover device as claimed in claim 2, it is characterised in that above-mentioned voltage generating unit includes：
One electric capacity；And
One charging circuit, couples above-mentioned comparator and above-mentioned electric capacity, and above-mentioned charging circuit has multiple current sources, above-mentioned charging electricity
The different current sources that road switches according to the comparative result of above-mentioned comparator in those current sources charge to above-mentioned electric capacity, wherein those
Different current sources in current source provide different size of electric current respectively.
4. power supply changeover device as claimed in claim 3, it is characterised in that when above-mentioned voltage generating unit is according to above-mentioned first time
When rate of rotation provides above-mentioned reference voltage, above-mentioned charging circuit is filled with one first current source in those current sources to above-mentioned electric capacity
Electricity, when the comparative result of above-mentioned comparator is higher than above-mentioned preset reference value for above-mentioned current sensing signal, above-mentioned charging circuit
Switched to according to the comparative result of above-mentioned comparator and above-mentioned electric capacity charged with one second current source in those current sources so that
Above-mentioned voltage generating unit changes provides above-mentioned reference voltage according to relatively low above-mentioned second revolution rate, and above-mentioned second current source is carried
One second electric current supplied is less than one first electric current that above-mentioned first current source is provided.
5. a kind of voltage-adjusting unit, couple a current sensing unit of a power supply changeover device, it is characterised in that above-mentioned voltage is adjusted
Whole unit includes：
One comparator, couples above-mentioned current sensing unit, and above-mentioned comparator receives a current sense from above-mentioned current sensing unit
Signal and more above-mentioned current sensing signal and a preset reference value；And
One voltage generating unit, couples above-mentioned comparator, and above-mentioned voltage generating unit provides a reference according to one first revolution rate
Voltage, when the comparative result of above-mentioned comparator is higher than above-mentioned preset reference value for above-mentioned current sensing signal, above-mentioned voltage production
Raw unit changes provides above-mentioned reference voltage according to one second revolution rate, wherein above-mentioned second revolution rate is less than the above-mentioned first revolution
Rate.
6. voltage-adjusting unit as claimed in claim 5, it is characterised in that above-mentioned current sensing unit senses above-mentioned power supply and turned
One output current of parallel operation is to provide above-mentioned current sensing signal.
7. voltage-adjusting unit as claimed in claim 5, it is characterised in that above-mentioned voltage generating unit includes：
One electric capacity；And
One charging circuit, couples above-mentioned comparator and above-mentioned electric capacity, and above-mentioned charging circuit has multiple current sources, above-mentioned charging electricity
The different current sources that road switches according to the comparative result of above-mentioned comparator in those current sources charge to above-mentioned electric capacity, wherein those
Different current sources in current source provide different size of electric current respectively.
8. voltage-adjusting unit as claimed in claim 7, it is characterised in that when above-mentioned voltage generating unit is according to above-mentioned first
When revolution rate provides above-mentioned reference voltage, above-mentioned charging circuit is filled with one first current source in those current sources to above-mentioned electric capacity
Electricity, when the comparative result of above-mentioned comparator is higher than above-mentioned preset reference value for above-mentioned current sensing signal, above-mentioned charging circuit
Switched to according to the comparative result of above-mentioned comparator and above-mentioned electric capacity charged with one second current source in those current sources so that
Above-mentioned voltage generating unit changes provides above-mentioned reference voltage according to relatively low above-mentioned second revolution rate, and above-mentioned second current source is carried
One second electric current supplied is less than one first electric current that above-mentioned first current source is provided.
9. a kind of voltage adjusting method, applied to a power supply changeover device, it is characterised in that above-mentioned voltage adjusting method includes following
Step：
(a) reference voltage is provided according to one first revolution rate；
(b) current sensing signal and more above-mentioned current sensing signal and a preset reference are received from above-mentioned power supply changeover device
Value；And
If (c) comparative result of step (b) is that above-mentioned current sensing signal is higher than above-mentioned preset reference value, change according to one second time
Rate of rotation provides above-mentioned reference voltage, wherein above-mentioned second revolution rate is less than above-mentioned first revolution rate.
10. voltage adjusting method as claimed in claim 9, it is characterised in that above-mentioned current sensing signal is the above-mentioned electricity of sensing
One output current of source converter and produce.
11. voltage adjusting method as claimed in claim 9, it is characterised in that step (a) is with 1 in multiple current sources
One current source charges to an electric capacity, with according to above-mentioned first revolution rate provide above-mentioned reference voltage when, when the comparison knot of step (b)
Fruit is above-mentioned current sensing signal when being higher than above-mentioned preset reference value, step (c) according to the comparative result of step (b) switch to
One second current source in those current sources charges to above-mentioned electric capacity, above-mentioned according to relatively low above-mentioned second revolution rate offer to change
Reference voltage, one second electric current that above-mentioned second current source is provided are less than one first electricity that above-mentioned first current source is provided
Stream.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| TW103133325 | 2014-09-25 | ||
| TW103133325A TWI547074B (en) | 2014-09-25 | 2014-09-25 | Power converter, voltage adjusting unit, and voltage adjusting method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN105720814A CN105720814A (en) | 2016-06-29 |
| CN105720814B true CN105720814B (en) | 2018-03-27 |
Family
ID=56145737
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201410712489.5A Active CN105720814B (en) | 2014-09-25 | 2014-12-01 | Power converter, voltage adjusting unit and voltage adjusting method |
Country Status (2)
| Country | Link |
|---|---|
| CN (1) | CN105720814B (en) |
| TW (1) | TWI547074B (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| TWI686039B (en) * | 2018-12-27 | 2020-02-21 | 大陸商北京集創北方科技股份有限公司 | Constant current soft start control circuit and power management chip using the same |
| TWI746099B (en) * | 2020-08-03 | 2021-11-11 | 茂達電子股份有限公司 | Converter having fast transient response |
| TWI788790B (en) * | 2021-02-25 | 2023-01-01 | 茂達電子股份有限公司 | Transient response predicting system and method with prediction mechanism of error amplified signal |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| TW200529550A (en) * | 2004-02-17 | 2005-09-01 | Novatek Microelectronics Corp | Apparatus and method for increasing a slew rate of an operational amplifier |
| TW201012054A (en) * | 2008-09-01 | 2010-03-16 | Novatek Microelectronics Corp | Rail-to-rail operational amplifier capable of reducing current consumption |
| CN101674008A (en) * | 2008-09-11 | 2010-03-17 | 光宝科技股份有限公司 | Discharge control device capable of regulating output current |
| TWI349425B (en) * | 2008-07-18 | 2011-09-21 | Novatek Microelectronics Corp | Driving circuit for enhancing response speed and related method |
| TWI369599B (en) * | 2008-02-22 | 2012-08-01 | ||
| CN102751879A (en) * | 2012-07-19 | 2012-10-24 | 魏其萃 | Method for controlling average output current at constant switching frequency in interrupted current mode |
| TW201340613A (en) * | 2012-03-23 | 2013-10-01 | Postech Acad Ind Found | Time difference amplifier and amplification method using slew rate control |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3600175B2 (en) * | 2000-03-23 | 2004-12-08 | 株式会社東芝 | Amplifier and liquid crystal display |
-
2014
- 2014-09-25 TW TW103133325A patent/TWI547074B/en active
- 2014-12-01 CN CN201410712489.5A patent/CN105720814B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| TW200529550A (en) * | 2004-02-17 | 2005-09-01 | Novatek Microelectronics Corp | Apparatus and method for increasing a slew rate of an operational amplifier |
| TWI369599B (en) * | 2008-02-22 | 2012-08-01 | ||
| TWI349425B (en) * | 2008-07-18 | 2011-09-21 | Novatek Microelectronics Corp | Driving circuit for enhancing response speed and related method |
| TW201012054A (en) * | 2008-09-01 | 2010-03-16 | Novatek Microelectronics Corp | Rail-to-rail operational amplifier capable of reducing current consumption |
| TWI357717B (en) * | 2008-09-01 | 2012-02-01 | Novatek Microelectronics Corp | Rail-to-rail operational amplifier capable of redu |
| CN101674008A (en) * | 2008-09-11 | 2010-03-17 | 光宝科技股份有限公司 | Discharge control device capable of regulating output current |
| TW201340613A (en) * | 2012-03-23 | 2013-10-01 | Postech Acad Ind Found | Time difference amplifier and amplification method using slew rate control |
| CN102751879A (en) * | 2012-07-19 | 2012-10-24 | 魏其萃 | Method for controlling average output current at constant switching frequency in interrupted current mode |
Also Published As
| Publication number | Publication date |
|---|---|
| TWI547074B (en) | 2016-08-21 |
| TW201613238A (en) | 2016-04-01 |
| CN105720814A (en) | 2016-06-29 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP3485562B1 (en) | Balancing charge pump circuits | |
| US9843259B2 (en) | Circuits and methods providing three-level signals at a synchronous buck converter | |
| US8148967B2 (en) | PWM clock generation system and method to improve transient response of a voltage regulator | |
| US10063078B2 (en) | Buck-boost battery charging circuit, control circuit and associated control method | |
| US10855181B2 (en) | PWM/PFM drive scheme for mutually coupled inductive coils | |
| US7242168B2 (en) | Wide input range buck/boost switching regulator | |
| US8907646B2 (en) | Power converting circuit and feedback control circuit | |
| CN107112895B (en) | Switching regulator and control method thereof | |
| US7592787B2 (en) | Adaptive firing order control for dynamic current balance of multiphase voltage regulators | |
| US20070064456A1 (en) | Multi-phase converter with improved load step-up transient response | |
| US10608539B1 (en) | Multi-phase power supply for stepdown system | |
| US20160141958A1 (en) | Switch control circuit and control method for a four-switch buck-boost converter | |
| CN103532378B (en) | Suppression output voltage crosses the electric pressure converter of punching | |
| CN103107697A (en) | Current regulating device and regulating method thereof | |
| CN110658877A (en) | Transient response techniques for voltage regulators | |
| US9496788B2 (en) | Multi-phase boost converter with phase self-detection and detecting circuit thereof | |
| CN105720814B (en) | Power converter, voltage adjusting unit and voltage adjusting method | |
| US20140098452A1 (en) | Power supply apparatus relating to dc-dc voltage conversion and having short protection function | |
| TW201926867A (en) | Single input multi output direct current power supply system and control circuit thereof | |
| US9143034B2 (en) | DC-DC controller and multi-ramp signal operating method thereof | |
| CN104953836B (en) | Step-up converter circuit and step-up converter circuit control method | |
| CN104682679B (en) | Power supply changeover device and its slope detecting controller and method | |
| US10008926B2 (en) | Switched capacitor DC-DC power converter circuit and voltage output method using the same | |
| US10298134B1 (en) | Switching converter soft start method using scaled switch size | |
| US9843252B1 (en) | Multi-phase power controller, multi-phase power control device and operation method of multi-phase power controller |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |