CN107046368A - Power supply change-over device - Google Patents
Power supply change-over device Download PDFInfo
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- CN107046368A CN107046368A CN201610081449.4A CN201610081449A CN107046368A CN 107046368 A CN107046368 A CN 107046368A CN 201610081449 A CN201610081449 A CN 201610081449A CN 107046368 A CN107046368 A CN 107046368A
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- synchronous rectification
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M3/00—Conversion of dc power input into dc power output
- H02M3/22—Conversion of dc power input into dc power output with intermediate conversion into ac
- H02M3/24—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters
- H02M3/28—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac
- H02M3/325—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal
- H02M3/335—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only
- H02M3/33507—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of the output voltage or current, e.g. flyback converters
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- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Dc-Dc Converters (AREA)
Abstract
The present invention provides a kind of power supply change-over device, and it includes power-switching circuit, synchronous rectification transistor, synchronous commutating control circuit, feedback circuit and line loss compensation circuit.Power-switching circuit carries out Power convert to input voltage, uses generation output voltage, and output voltage is supplied into load.Synchronous rectification transistor is serially connected with the secondary side current path of power-switching circuit, and is controlled by synchronous rectification control signal and switched conductive state.Synchronous commutating control circuit produces synchronous rectification control signal to control the switching of synchronous rectification transistor.Feedback circuit produces the output indication electric current for being associated with output voltage.Line loss compensation circuit draws compensation electric current according to synchronous rectification control signal from feedback circuit, uses the summation based on compensation electric current and output indication electric current and compensates output voltage.
Description
Technical field
Turn the present invention relates to a kind of power supply change-over device, more particularly to a kind of power supply that can compensate for line loss
Changing device.
Background technology
Power supply change-over device (power conversion apparatus) main purposes is by institute of Utilities Electric Co.
The input voltage (input voltage) of the high pressure of offer and low stability is converted into being adapted to various electronic installations
Low pressure and stability preferably VD (DC output that (electronic device) is used
voltage).Therefore, power supply change-over device be widely used in computer, office automation devices,
In the electronic installation such as industrial control equipment and communication apparatus.
When the required power supply of load end is larger, power supply change-over device needs to provide larger output current
So that load is used, now the operating state of power supply change-over device is referred to as heavily loaded running.In heavy duty running
Under, because larger output current would generally cause pressure drop online in output, offer so may be made extremely
The voltage of load end exceeds specification.Such a phenomenon is commonly referred to as line loss (cable loss).
Some line loss compensation mechanism would generally be used in existing power supply change-over device to compensate in heavy duty fortune
Output voltage pressure drop when making caused by line loss.In typically conventional line loss compensation mode, its
It is middle it is a kind of be cut-off by detection power switch during length to judge output current size, then determine accordingly
Determine the compensation rate of output voltage；Wherein another is directly to be detected by setting output current detection circuit
Output current size, then the compensation rate of output voltage is determined accordingly.
However, due to when power supply change-over device running is in continuous conduction mode (continuous conduction
Mode, CCM) when, it is to fix and output current size can not be reacted during its cut-off, therefore according to work(
The mode that line loss compensation is carried out during the cut-off of rate switch is only capable of applying in discontinuous conduction mode
The power supply change-over device of (discontinuous conduction mode, DCM).
On the other hand, because the current detection mechanism of general current detection circuit is typically to be exported by sampling
Electric current, then sampling current is flowed through a specific electrical resistance, use by measuring the ohmically cross-pressure to judge
The sampling current size of the resistance is flowed through, is pushed back further according to sampling current and calculates output current size.Cause
This, under general output electric current measure mode, it will certainly cause extra power consumption.
The content of the invention
In view of this, the present invention provides a kind of power supply change-over device, uses and solves what prior art was addressed
Problem.
The power supply change-over device of the present invention includes power-switching circuit, synchronous rectification transistor, synchronous rectification
Control circuit, feedback circuit and line loss compensation circuit.Power-switching circuit to input voltage to carry out
Power convert, uses generation output voltage, and output voltage is supplied into load.Synchronous rectification crystal
Pipe is serially connected with the secondary side current path of power-switching circuit, and is controlled by synchronous rectification control signal
And switched conductive state.Synchronous commutating control circuit couples synchronous rectification transistor, synchronous whole to produce
Flow control signals are to control the switching of synchronous rectification transistor.Feedback circuit couples power-switching circuit, uses
To produce the output indication electric current for being associated with output voltage.Line loss compensation circuit coupling synchronous rectification control electricity
Road and feedback circuit, to draw compensation electric current from feedback circuit according to synchronous rectification control signal, by
Output voltage is compensated with the summation based on compensation electric current and output indication electric current.
Based on a kind of above-mentioned, power supply change-over device of present invention proposition, it includes one using synchronous rectification control
Signal processed as the foundation of line loss compensation line loss compensation circuit.Wherein, the line loss compensation circuit can base
The compensation electric current corresponding to output current size is produced in synchronous rectification control signal, and is compensated accordingly defeated
Go out line loss of the voltage in heavy duty.Because no matter under DCM or CCM, synchronous rectification control is believed
Number waveform all may indicate that output current size, therefore the embodiment of the present invention power supply change-over device either
Running all can effectively carry out line loss compensation, without being limited to Power convert under DCM or CCM
The operating mode of device.Further, since the power supply change-over device of the embodiment of the present invention and being not required to using extra
Current detection circuit directly output current is detected, therefore power supply change-over device overall power damage
Consumption is minimized.
For the features described above and advantage of the present invention can be become apparent, special embodiment below, and coordinate
Accompanying drawing is described in detail below.
Brief description of the drawings
Fig. 1 is the function box schematic diagram of the power supply change-over device of one embodiment of the invention；
Fig. 2 is the circuit diagram of the power supply change-over device of one embodiment of the invention；
Fig. 3 is the signal sequence schematic diagram of the power supply change-over device of one embodiment of the invention；
Fig. 4 is the signal sequence schematic diagram of the power supply change-over device of another embodiment of the present invention.
Reference：
100、200：Power supply change-over device
110、210：Power-switching circuit
120、220：Synchronous rectification transistor
130、230：Synchronous commutating control circuit
140、240：Feedback circuit
150、250：Line loss compensation circuit
Ib：Base current
Iout：Output current
Iic：Output indication electric current
Icomp：Compensate electric current
C1、C2：Electric capacity
Cin：Input capacitance
Cout：Output capacitance
CTP：Control chip
GND1、GND2：Earth terminal
NB、NC：Node
NP：First side winding
NS：Secondary side is wound
PC：Photo-coupler
PSW：Power switch
LD：Load
Rb、Ri、R1、R2、R3、R4、R5：Resistance
Spwm：Pulse-width modulation signal
Ssr：Synchronous rectification control signal
T：Transformer
T1、T2、T3：Cycle
V1、V2、V3、Vb、Vnb：Voltage
Vin：Input voltage
Vout：Output voltage
Vth：Barrier voltages
Vfb：Feedback voltage
U1：Voltage-stablizer
Vu：Voltage of voltage regulation
Q1：Transistor
DCM：Discontinuous conduction mode
CCM：Continuous conduction mode
Embodiment
In order that present disclosure can easily be understood, below especially exemplified by embodiment as of the invention true
The example that can implement according to this in fact.In addition, all possible parts, using identical in drawings and the embodiments
Component/component/step of label, represents same or like part.
Fig. 1 is the schematic diagram of the power supply change-over device of one embodiment of the invention.It refer to Fig. 1, this implementation
The power supply change-over device 100 of example is whole including power-switching circuit 110, synchronous rectification transistor 120, synchronization
Flow control circuit 130, feedback circuit 140 and detection auxiliary circuit 130.
Power-switching circuit 110 can be for example with synchronous rectification (synchronous rectification
Function flyback power converter (flyback converter)).In the present embodiment, power supply turns
Change circuit 110 and carry out Power convert to receive input voltage vin, and to input voltage vin, by
To produce the output voltage Vout of direct current, wherein output voltage Vout can be provided to load LD, wherein
It may be, for example, any kind of electronic installation to load LD, and the present invention is any limitation as not to this.
Synchronous rectification transistor 120 be serially connected with the secondary side current path of power-switching circuit 110 (after
The circuit framework of continuous embodiment can be particularly shown), and be controlled by synchronous commutating control circuit 130 and produced
Raw synchronous rectification control signal Ssr and switched conductive state.
Synchronous commutating control circuit 130 couples synchronous rectification transistor 120, and in conjunction with Power convert
The power switch (not shown) switching sequence of circuit 110 and corresponding synchronous rectification control signal Ssr is provided
To control the switching of synchronous rectification transistor 120 so that secondary side power supply may be provided to load LD ends.
Feedback circuit 140 couples power-switching circuit 110, and it can be used to sample in the output end of secondary side
Output voltage Vout, and produce be associated with output voltage Vout output indication electric current Iic according to this.
In addition, feedback circuit 140 can be also coupled back into the information of voltage being sampled to as feedback voltage Vfb once
Side is to be supplied to power-switching circuit 110 as the foundation of control.
Line loss compensation circuit 150 couples synchronous commutating control circuit 130 and feedback circuit 140, and it can use
With the synchronous rectification control signal Ssr produced by foundation synchronous commutating control circuit 130 from feedback circuit
Corresponding compensation electric current Icomp is drawn in 140.Thereby, except original based on output in feedback circuit 140
Outside the voltage that indicator current Iic is set up, line loss compensation circuit 150 can be based on the compensation electric current drawn
Icomp and extra voltage is set up in feedback circuit 140 to compensate output voltage Vout.In other words,
Line loss compensation circuit 150 can be defeated to compensate based on compensation electric current Icomp language output indication electric currents Iic summation
Go out voltage Vout.
Specifically, in the synchronous commutating control circuit 130 that the present embodiment is applied, produced by it
No matter synchronous rectification control signal Ssr operates in continuous conduction mode (continuous conduction
Mode, CCM) or discontinuous conduction mode (discontinuous conduction mode, DCM) under,
All there is the characteristic that waveform can change with output current Iout sizes/load weight.The line loss of the present embodiment is mended
Repay circuit 150 mainly use the characteristic as the operating state for judging power-switching circuit 110 according to
According to being produced based on synchronous rectification control signal Ssr and be associated with output current size and load LD weights change
Compensation electric current Icomp compensate the pressure drop of the output voltage Vout in high current/heavy duty.
More specifically, compared to according to power switch cut-off during carry out line loss compensation mode for,
The line loss compensation mode of the present embodiment can be applied under DCM and CCM simultaneously, and be not only restricted to power supply and turned
Change the operating mode of circuit 110.On the other hand, compared to directly detecing side output current Iout and enter according to this
For the mode of row line loss compensation, the line loss compensation mode of the present embodiment is due to being not required to directly to output current
Iout is detected, therefore can reduce power attenuation.
Illustrate the line loss compensation mechanism of the present embodiment with the physical circuit shown by Fig. 2 below.Wherein,
Fig. 2 is the circuit diagram of the power supply change-over device of one embodiment of the invention.
Fig. 2 is refer to, the power supply change-over device 200 of the present embodiment includes power-switching circuit 210, synchronization
Rectifying transistor 220, synchronous commutating control circuit 230, feedback circuit 240 and line loss compensation circuit
250.Wherein, power-switching circuit 210 include transformer T, input capacitance Cin, power switch PSW,
Control chip CTP and output capacitance Cout.Line loss compensation circuit 250 includes resistance R1, resistance R2
And Rb, electric capacity C1 and transistor Q1.Feedback circuit 240 includes resistance R3, resistance R4 and resistance
R5, electric capacity C2, voltage-stablizer U1 and photo-coupler PC.
In power-switching circuit 210, transformer T has first side winding (primary winding)
Np winds (secondary winding) Ns with secondary side.Wherein, a lateral circuit (first side winding
Np side) be using earth terminal GND1 as voltage reference points, and secondary side circuit (secondary side around
Hinder Ns side) it is then that voltage reference points are used as using earth terminal GND2.Wherein, earth terminal GND1
Can be identical or different ground plane with GND2, the present invention is any limitation as not to this.
(common-polarity terminal, that is, get ready transformer T first side winding Np Same Name of Ends
Place) coupling power switch PSW, and transformer T first side winding Np different name end
(opposite-polarity terminal, i.e., the place of not getting ready) is to receive input voltage vin.Transformer T
Secondary side winding Ns Same Name of Ends coupling output capacitance Cout first end, and the two of transformer T
Secondary side winding Ns different name end is coupled to the second of output capacitance Cout via synchronous rectification transistor 220
End and the earth terminal GND2 of secondary side.
Control chip CTP coupling power switch PSW control end, uses offer pulse-width modulation signal
Spwm controls power switch PSW switching.Power switch PSW in this be, for example, using NMOS as
Example.Power switch PSW first end (in this to drain, but is not limited only to this, visual power switch
Depending on PSW type) coupling transformer T first side winding Np Same Name of Ends, power switch PSW
The second end (in this be source electrode) coupling earth terminal GND1, and power switch PSW control end (in
This is grid) then to receive the pulse-width modulation signal Spwm from control chip 120.
Input capacitance Cin first end coupling first side winding Np different name end, and input capacitance Cin
The second end coupling earth terminal GND1.Output capacitance Cout first end coupling secondary side winding Ns's
Same Name of Ends, and output capacitance Cout the second end coupling earth terminal GND2.
Synchronous rectification transistor 220 is, for example, by taking NMOS as an example in this.Synchronous rectification transistor 220
First end (in this to drain, but is not limited only to this, depending on the type of visual synchronous rectification transistor 220)
Couple output capacitance Cout the second end, the second end of synchronous rectification transistor 220 (in this be source electrode)
Couple transformer T secondary side winding Ns different name end, and the control of synchronous rectification transistor 220
End (in this be grid) to receive the synchronous rectification control signal from synchronous commutating control circuit 23
Ssr.In other words, the first end of synchronous rectification transistor 220 is to be serially connected in secondary side winding with the second end
On Ns current path, therefore the conducting state of synchronous rectification transistor 220 can determine secondary side current road
Whether footpath is interrupted.
In feedback circuit 240, resistance R3 first end coupling output capacitance Cout first end.Electricity
Hinder R4 first end coupling resistance R3 the second end, and resistance R4 the second end coupling earth terminal
GND2.Resistance R5 first end coupling resistance R3 the second end and resistance R4 first end.Electric capacity
C2 first end coupling resistance R5 the second end.
The first end coupling resistance R3 of photo-coupler PC input side first end, and photo-coupler PC
Input side the second end coupling capacitance C2 the second end.The first end of photo-coupler PC outlet side is defeated
Go out feedback voltage Vfb, and the second end coupling earth terminal GND1 of photo-coupler PC outlet side.
The of voltage-stablizer U1 first end coupling capacitance C2 the second end and photo-coupler PC input side
Two ends, voltage-stablizer U1 the second end coupling earth terminal GND2, and voltage-stablizer U1 voltage stabilizing end coupling
Resistance R3 the second end and resistance R4 first end (that is, node NC), and on node NC
Voltage carry out voltage stabilizing operation.
Wherein, photo-coupler PC can in conjunction with voltage-stablizer U1 running and according to VD Vout
The feedback voltage Vfb for being associated with output voltage Vout sizes in the generation of its outlet side gives control chip CTP,
To make control chip CTP to be used as the foundation for controlling power switch PSW according to feedback voltage Vfb.
In line loss compensation circuit 250, resistance R1 first end coupling synchronous commutating control circuit 230
Signal output part, use reception synchronous rectification control signal Ssr.Resistance R2 first end is coupled to section
Point NC (that is, the first end of the resistance R4 in feedback circuit 240).Electric capacity C1 first end coupling
Resistance R1 the second end, and electric capacity C1 the second end coupling earth terminal GND2.Transistor Q1 in
This is, for example, by taking BJT as an example.Transistor Q1 first end (in this be collector) coupling resistance R2 the
Two ends, transistor Q1 the second end (in this be emitter-base bandgap grading) coupling earth terminal GND2, and transistor
Q1 base stage coupling resistance R1 the second end and electric capacity C1 first end.
Specifically, it is in power supply change-over device 200 under normal operation, control chip CTP can react
Pulse-width modulation signal Spwm is accordingly produced in the power supply supply requirement of load to control Power convert electricity
The running on road 210.On this condition, produced by power switch PSW reacts on control chip CTP
Pulse-width modulation signal Spwm and when turning on (turned on), input voltage vin can be connected across transformation
Device T first side winding Np, so that transformer T first side winding Np inductive current can be linear
Increase and carry out energy storage.At the same time, synchronous commutating control circuit 230 can be produced in secondary side winding Ns sides
The synchronous rectification control signal Ssr of forbidden energy is given birth to end (turned off) synchronous rectification transistor 220.By
In the barrier of the synchronous rectification transistor 220 of cut-off, so transformer T secondary side winds Ns by nothing
Electric current passes through.
Pulse-width modulation signal Spwm produced by power switch PSW reacts on control chip CTP and
During cut-off, based on Lenz's law (Lenz's law), stored by transformer T first side winding Np
Energy can be transferred to transformer T secondary side winding Ns.At the same time, synchronous commutating control circuit 230
It can produce the synchronous rectification control signal Ssr of enable to turn on synchronous rectification crystal in secondary side winding Ns sides
Pipe 220.Because synchronous rectification transistor 220 is switched on, thus be transferred to transformer T secondary side around
Group Ns energy will charge to output capacitance Cout, and supply output voltage Vout to load
(electronic installation).
It follows that alternately being led based on the pulse-width modulation signal Spwm produced by control chip CTP
The logical function mode that PSW is switched with stop power, power supply change-over device 200 i.e. sustainably supply output
Voltage Vout.
On the other hand, from the point of view of with regard to the running of line loss compensation circuit 250, in synchronous rectification control signal Ssr
In the case of enable, electric capacity C1 can react on synchronous rectification control signal Ssr voltage quasi position and carry out
Charging so that the voltage Vnb on node NB can be interior during synchronous rectification control signal Ssr enable
Gradually rise, and be maintained at specific by electric capacity C1 when synchronous rectification control signal Ssr switches to forbidden energy
Magnitude of voltage on.
When the cross-pressure between transistor Q1 base stage and emitter-base bandgap grading exceedes barrier voltages, transistor Q1 can be produced
There is the emitter current of multiple proportion with base current, that is, flow through resistance R2 compensation electric current Icomp.
Compensate under the uncreated situations of electric current Icomp, output voltage Vout can be equal to output indication electric current Iic
The resistance value (that is, resistance R3 cross-pressure) for being multiplied by resistance R3 adds voltage of voltage regulation Vu (with formula table
Show, as Vout=Iic*R3+Vu).When compensating electric current Icomp generations, because transistor Q1 is
Electric current all the way is additionally drawn from node Nc so that the electric current for flowing through resistance R3 becomes output indication electric current
Iic is plus compensation electric current Icomp.In other words, in the case where compensation electric current Icomp is produced, output electricity
The current value summation that pressure Vout can be equal to output indication electric current Iic and compensation electric current Icomp is multiplied by resistance R3
Resistance value add voltage of voltage regulation Vu (being represented with formula, as Vout=(Iic+Icomp) * R3+Vu).
As shown from the above formula, when line loss compensation circuit 250 reacts on synchronous rectification control signal Ssr and
When producing compensation electric current Icomp, it is that can draw high output voltage Vout, so as to reach compensation output electricity
Press Vout effect.In addition, because the size for compensating electric current Icomp is the electricity on node NB
Vnb is pressed to determine, and the voltage quasi position that voltage Vnb level height can be with synchronous rectification control signal Ssr
It is proportionate with the product of enable time, wherein synchronous rectification control signal Ssr voltage quasi position and enable
The product of time is that can indicate output current Iout sizes.Therefore, the line loss compensation circuit 250 of the present embodiment
It can be achieved to provide corresponding offset to compensate output voltage with output current Iout sizes/load weight
Vout effect.
It is beneath to illustrate that the power supply change-over device 200 of the present embodiment is operated in DCM respectively with Fig. 3 and Fig. 4
With the signal sequence under CCM.
The signal sequence that power supply change-over device 200 is operated in DCM is as shown in Figure 3.Please first referring concurrently to
Fig. 2 and Fig. 3, due to be not under DCM, during power switch PSW cut-off it is fixed, therefore
Changed during the cut-off with power switch PSW during synchronous rectification control signal Ssr enable.
In addition, in synchronous rectification control signal Ssr signal waveform, it, which has, to decay after specific period
Characteristic.In other words, under DCM, synchronous rectification control signal Ssr enable waveform area and output
Electric current Iout sizes are proportionate.
The present embodiment is to illustrate the power supply change-over device 200 in different loads to load gradually increased situation
Under running.In cycle T 1, now light load, during synchronous rectification control signal Ssr enable
It is shorter so that transistor Q1 base voltage Vb has not exceeded barrier voltages Vth in cycle T 1,
Therefore line loss compensation circuit 250 will not also make output voltage to power-switching circuit 210 in cycle T 1
Vout is compensated, therefore output voltage Vout magnitude of voltage can be maintained substantially on V1 in cycle T 1.
When loading raising, such as function situation of cycle T 2, synchronous rectification control signal Ssr enable phase
Between can with increase.Because electric capacity C1 interior during synchronous rectification control signal Ssr enable can continue quilt
Charging so that transistor Q1 base voltage Vb can exceed barrier voltages Vth.In the case, it is electric
Pressure Vnb and base voltage Vb pressure difference can set up base current Ib on resistance Rb so that compensation electric current
Icomp can therewith be produced and (be had β multiple proportions with base current Ib).Wherein, output voltage Vout
Magnitude of voltage V2 is pulled to because of compensation electric current Icomp effect, uses when compensation load is improved and is produced
Raw pressure drop.
Similarly, in successively cycle T 3, as output loading continues to increase, base current Ib
Area increases and improved during the enable with synchronous rectification control signal Ssr so that compensation electric current Icomp
Also increase, so that output voltage Vout is pulled to magnitude of voltage V3 from magnitude of voltage V2 again, it is negative to compensate
Carry pressure drop produced when improving.
The signal sequence that power supply change-over device 200 is operated in CCM is as shown in Figure 4.Referring to Fig. 2
With Fig. 4, due to being fixed during power switch PSW cut-off under CCM so that synchronous whole
Also it is fixation during flow control signals Ssr enable.But, it is synchronous when output current Iout is larger
Rectification control signal Ssr relatively can just decay slowly；On the contrary, when output current Iout is smaller, it is synchronous whole
Flow control signals Ssr then can more early decay.In other words, under CCM, synchronous rectification control signal Ssr
Enable waveform area same with output current Iout sizes be proportionate.
The present embodiment is equally to illustrate the power supply change-over device 200 in difference to load gradually increased situation
Running under load.In cycle T 1, due to now light load, synchronous rectification control signal Ssr's
Voltage quasi position can more early decay so that voltage quasi positions of the voltage Vnb in cycle T 1 on node NB
It is relatively low, therefore the compensation electric current Icomp in cycle T 1 produced by line loss compensation circuit 250 is smaller, therefore
Output voltage Vout magnitude of voltage can be maintained substantially on V1 in cycle T 1.
When loading raising, such as function situation of cycle T 2, synchronous rectification control signal Ssr voltage is accurate
Position can delay later just decay so that the time that electric capacity C1 is charged with high voltage level is longer, therefore order
The voltage quasi position of voltage Vnb on node NB rises.In the case, because base current Ib can be with
Voltage Vnb rising and rise therewith, and compensate electric current Icomp size and base current Ib
There is multiple proportion, therefore output voltage Vout can be because of the effect for compensating electric current Icomp from magnitude of voltage
V1 is pulled to magnitude of voltage V2, uses pressure drop produced when compensation load is improved.
Similarly, in successively cycle T 3, as output loading continues to increase, base current Ib
Area increases and improved during the enable with synchronous rectification control signal Ssr so that compensation electric current Icomp
Also increase, so that output voltage Vout is pulled to magnitude of voltage V3 from magnitude of voltage V2 again, it is negative to compensate
Carry pressure drop produced when improving.
In summary, the present invention proposes a kind of power supply change-over device, and it includes one using synchronous rectification control
Signal processed as the foundation of line loss compensation line loss compensation circuit.Wherein, the line loss compensation circuit can base
The compensation electric current corresponding to output current size is produced in synchronous rectification control signal, and is compensated accordingly defeated
Go out line loss of the voltage in heavy duty.Because no matter under DCM or CCM, synchronous rectification control is believed
Number waveform all may indicate that output current size, therefore the embodiment of the present invention power supply change-over device either
Running all can effectively carry out line loss compensation, without being limited to Power convert under DCM or CCM
The operating mode of device.Further, since the power supply change-over device of the embodiment of the present invention and being not required to using extra
Current detection circuit directly output current is detected, therefore power supply change-over device overall power damage
Consumption is minimized.
Although the present invention is disclosed as above with embodiment, so it is not limited to the present invention, any affiliated
Those of ordinary skill in technical field, it is without departing from the spirit and scope of the present invention, a little when that can make
Change with retouching, therefore protection scope of the present invention ought be defined depending on appended claims confining spectrum.
Claims (9)
1. a kind of power supply change-over device, it is characterised in that including：
One power-switching circuit, to carry out Power convert to an input voltage, uses the output electricity of generation one
Pressure, and the output voltage is supplied to a load；
One synchronous rectification transistor, is serially connected with a secondary side current path of the power-switching circuit,
And it is controlled by a synchronous rectification control signal and switched conductive state；
One synchronous commutating control circuit, couples the synchronous rectification transistor, whole to produce the synchronization
Flow control signals are to control the switching of the synchronous rectification transistor；
One feedback circuit, couples the power-switching circuit, the output voltage is associated with to produce
One output indication electric current；And
One line loss compensation circuit, couples the synchronous commutating control circuit and the feedback circuit, to according to
A compensation electric current is drawn from the feedback circuit according to the synchronous rectification control signal, is used based on described
The summation for compensating electric current and the output indication electric current compensates the output voltage.
2. power supply change-over device according to claim 1, it is characterised in that the synchronous rectification control
The waveform of signal processed is with the output current size variation produced by the power-switching circuit.
3. power supply change-over device according to claim 1, it is characterised in that the compensation electric current
Size is proportionate with an enable time of the synchronous rectification control signal and the product of a voltage quasi position.
4. power supply change-over device according to claim 1, it is characterised in that the line loss compensation electricity
Road includes：
One first resistor, its first end couples the synchronous commutating control circuit, uses the reception synchronization
Rectification control signal；
One second resistance, its first end couples the feedback circuit；
One first electric capacity, its first end couples the second end of the first resistor, and its second end coupling one
Secondary side earth terminal；And
One the first transistor, its first end couples the second end of the second resistance, its second end coupling institute
Earth terminal is stated, and its control end couples the second end of the first resistor and the first end of first electric capacity.
5. power supply change-over device according to claim 4, it is characterised in that flow through second electricity
The electric current of resistance is the compensation electric current.
6. power supply change-over device according to claim 4, it is characterised in that the Power convert electricity
Road includes：
One transformer, with a first side winding and a secondary side winding, wherein the first side winding
Different name end receives the input voltage；
One input capacitance, its first end couples the different name end of the first side winding, and its second end is coupled
One side joint ground terminals；
One power switch, its first end couples the Same Name of Ends of the first side winding, and its second end is coupled
The primary side earth terminal；
One control chip, couples the control end of the power switch, uses one pulse-width modulation signal of offer and comes
Control the switching of the power switch；And
One output capacitance, its first end couples the Same Name of Ends of the secondary side winding, and its second end is coupled
The secondary side earth terminal.
7. power supply change-over device according to claim 6, it is characterised in that the synchronous rectification is brilliant
The first end of body pipe couples the second end of the output capacitance, the second end coupling of the synchronous rectification transistor
The different name end of the secondary side winding is connect, and the control end of the synchronous rectification transistor couples the synchronization
Rectifier control circuit.
8. power supply change-over device according to claim 6, it is characterised in that the feedback circuit bag
Include：
One 3rd resistor, its first end couples the first end of the output capacitance, and its second end coupling institute
State the first end of second resistance；
One the 4th resistance, its first end couples the of the first end of the second resistance and the 3rd resistor
Two ends, and its second end couples the secondary side earth terminal；
One the 5th resistance, its first end couples the of the second end of the 3rd resistor and the 4th resistance
One end；
One second electric capacity, its first end couples the second end of the 5th resistance；And
One voltage-stablizer, its first end couples the second end of second electric capacity, its second end coupling described two
Secondary side joint ground terminal, and its voltage stabilizing end couples the second end and the first of the 4th resistance of the 3rd resistor
End.
9. power supply change-over device according to claim 8, it is characterised in that flow through the 4th electricity
The electric current of resistance is the output indication electric current, and it is that the output refers to flow through the electric current of the 3rd resistor
Show the summation of electric current and the compensation electric current.
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| Application Number | Priority Date | Filing Date | Title |
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| CN201610081449.4A CN107046368B (en) | 2016-02-05 | 2016-02-05 | Power supply change-over device |
| US15/161,300 US9729073B1 (en) | 2016-02-05 | 2016-05-23 | Power conversion apparatus |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610081449.4A CN107046368B (en) | 2016-02-05 | 2016-02-05 | Power supply change-over device |
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| CN107046368A true CN107046368A (en) | 2017-08-15 |
| CN107046368B CN107046368B (en) | 2019-03-08 |
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| CN201610081449.4A Active CN107046368B (en) | 2016-02-05 | 2016-02-05 | Power supply change-over device |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN111596115A (en) * | 2019-02-01 | 2020-08-28 | 群光电能科技股份有限公司 | Method for measuring output current by resistance compensation and conversion circuit thereof |
| CN111698812A (en) * | 2019-02-27 | 2020-09-22 | 宏碁股份有限公司 | Voltage compensation driving circuit |
| CN112785954A (en) * | 2019-11-04 | 2021-05-11 | 海信视像科技股份有限公司 | Display device and compensation circuit |
| US11900855B2 (en) | 2019-11-04 | 2024-02-13 | Hisense Visual Technology Co., Ltd. | Display apparatus |
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| CN102904449A (en) * | 2011-07-26 | 2013-01-30 | 崇贸科技股份有限公司 | Regulation circuit providing cable compensation for power converter |
| JP2013118780A (en) * | 2011-12-05 | 2013-06-13 | Sanken Electric Co Ltd | Switching power supply device |
| CN105094189A (en) * | 2014-05-14 | 2015-11-25 | 登丰微电子股份有限公司 | Cable loss compensation circuit and power supply circuit having cable loss compensation |
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| CN102904449A (en) * | 2011-07-26 | 2013-01-30 | 崇贸科技股份有限公司 | Regulation circuit providing cable compensation for power converter |
| JP2013118780A (en) * | 2011-12-05 | 2013-06-13 | Sanken Electric Co Ltd | Switching power supply device |
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| CN111596115A (en) * | 2019-02-01 | 2020-08-28 | 群光电能科技股份有限公司 | Method for measuring output current by resistance compensation and conversion circuit thereof |
| CN111698812A (en) * | 2019-02-27 | 2020-09-22 | 宏碁股份有限公司 | Voltage compensation driving circuit |
| CN111698812B (en) * | 2019-02-27 | 2022-10-21 | 宏碁股份有限公司 | Voltage compensation driving circuit |
| CN112785954A (en) * | 2019-11-04 | 2021-05-11 | 海信视像科技股份有限公司 | Display device and compensation circuit |
| US11900855B2 (en) | 2019-11-04 | 2024-02-13 | Hisense Visual Technology Co., Ltd. | Display apparatus |
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| Publication number | Publication date |
|---|---|
| CN107046368B (en) | 2019-03-08 |
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