CN110212766A - A kind of power supply and its power circuit - Google Patents
A kind of power supply and its power circuit Download PDFInfo
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- CN110212766A CN110212766A CN201810166573.XA CN201810166573A CN110212766A CN 110212766 A CN110212766 A CN 110212766A CN 201810166573 A CN201810166573 A CN 201810166573A CN 110212766 A CN110212766 A CN 110212766A
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- Prior art keywords
- voltage
- module
- sampling
- output
- power circuit
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Classifications
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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
- H02M1/00—Details of apparatus for conversion
- H02M1/08—Circuits specially adapted for the generation of control voltages for semiconductor devices incorporated in static converters
-
- 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
- H02M1/00—Details of apparatus for conversion
- H02M1/14—Arrangements for reducing ripples from dc input or output
- H02M1/15—Arrangements for reducing ripples from dc input or output using active elements
-
- 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
- H02M3/33523—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 with galvanic isolation between input and output of both the power stage and the feedback loop
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- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Dc-Dc Converters (AREA)
Abstract
The invention belongs to power technique fields, a kind of power supply and its power circuit are provided.In the present invention, compensating module is pressed by using including output line, sampling and keep module, erasing time sampling module, the control chip of error amplification module and drive module, so that the control chip is when controlling the power switch tube in power circuit, the sampling of sampling and keep module output keeps voltage that can change with the output voltage of power circuit, so that the output of error amplification module changes with the output voltage of power circuit, to improve the stability for the compensation loop for controlling chip, reduce the output ripple of power circuit, it solves the problems, such as existing power circuit there are output ripples and is big.
Description
Technical field
The invention belongs to power technique fields more particularly to a kind of power supplys and its power circuit.
Background technique
The device of power is provided as to various electrical equipments, the importance of power supply is self-evident.Currently, prior art institute
The power circuit of use is mainly typical inverse-excitation type switch power-supply application circuit.The inverse-excitation type switch power-supply route mainly passes through control
The driving signal control power switch tube of coremaking piece output and the armature winding of transformer are connected, in specific power switch tube
It is realized in switch periods from primary to secondary circuit and transmits energy, thus to power supply for electrical equipment, and the power circuit is real
Mainly pass through control chip sampling transformer ancillary coil (feedback winding) voltage when existing constant pressure, and the voltage that sampling is obtained is made
It is feedback voltage the mode that is controlled the output voltage of power circuit.
However, due on transformer ancillary coil voltage could only reflect output voltage feelings within the secondary erasing time
Condition, therefore, control chip to the sampling of output voltage can only within the secondary erasing time, and the secondary erasing time i.e. sample when
Between external control coremaking piece feed back input will keep, so by make control chip can not real-time tracking output voltage variation.And
Under underloading, since the system operating frequency of power circuit is lower, while peak point current is smaller, therefore sampling time phase at this time
It is very small for the system duty cycle of power circuit, therefore the sampled voltage for controlling chip will not catch up with the change of output voltage far
Change, and then the variation for controlling chip output is caused not catch up with the pace of change of output voltage much, so that controlling chip
In control loop it is unstable, and the shakiness of loop will introduce low-frequency ripple, so that the output ripple of power circuit is bigger than normal.
In conclusion existing power circuit has that output ripple is big.
Summary of the invention
The purpose of the present invention is to provide a kind of power supply and its power circuits, it is intended to which solving existing power circuit, there are defeated
The big problem of ripple out.
The invention is realized in this way a kind of power circuit, connects with load, the power circuit includes rectifier bridge, becomes
Die block, power switch tube and control chip, the rectifier bridge connect with the voltage changing module, the voltage changing module with it is described
Power switch tube, the control chip and load connection, the control chip is connect with the power switch tube, described
Control chip include: output line pressure compensating module, sampling and keep module, erasing time sampling module, error amplification module and
Drive module；
The sampling and keep module presses compensating module with the voltage changing module, the drive module and the output line
Connection, for generating sampling according to the driving control signal of the sampled voltage of the voltage changing module and drive module output
Voltage is kept, and presses the load current of compensating module output to adjust the sampling according to the output line and keeps voltage, so that institute
Stating sampling keeps voltage to change with the output voltage of the power circuit；
The error amplification module, connect with the sampling and keep module, for being generated according to the sampling and keep module
Sampling keep voltage and received first reference voltage to generate error amplifying voltage；
The output line presses compensating module, connect with the error amplification module and the voltage changing module, is used for basis
The error amplification voltage that the secondary coil voltage of the voltage changing module and the error amplification module generate is to the sampled voltage
It is adjusted, and the load current is exported according to the secondary coil voltage；Wherein, the secondary coil voltage and the electricity
The proportional relationship of the output voltage of source circuit；
The erasing time sampling module, connect with the voltage changing module, for generating demagnetization according to the sampled voltage
Time；
The drive module, with the erasing time sampling module, the error amplification module and the power switch
Pipe connection, the output electric current for amplifying voltage, the erasing time and the power switch tube according to the error generate
Switching drive signal and the driving control signal, and according to the switching drive signal drive the power switch tube conducting or
Shutdown.
Another object of the present invention is to provide a kind of power supply, the power supply includes above-mentioned power circuit.
In the present invention, mould is sampled by using including output line pressure compensating module, sampling and keep module, erasing time
The control chip of block, error amplification module and drive module, so that the control chip is to the power switch in power circuit
When pipe is controlled, the sampling of sampling and keep module output keeps voltage that can change with the output voltage of power circuit, and then makes
The output of error amplification module is obtained as the output voltage of power circuit changes, to improve the steady of the compensation loop of control chip
It is qualitative, the output ripple of power circuit is reduced, existing power circuit is solved the problems, such as there are output ripples and is big.
Detailed description of the invention
Fig. 1 is the modular structure schematic diagram of power circuit provided by one embodiment of the invention；
Fig. 2 is the modular structure schematic diagram of the sampling and keep module in power circuit provided by one embodiment of the invention；
Fig. 3 is the electrical block diagram of the sampling and keep module in power circuit provided by one embodiment of the invention；
Fig. 4 is the waveform diagram of power circuit provided by one embodiment of the invention；
Fig. 5 is another waveform diagram of power circuit provided by one embodiment of the invention.
Specific embodiment
In order to make the objectives, technical solutions, and advantages of the present invention clearer, with reference to the accompanying drawings and embodiments, right
The present invention is further elaborated.It should be appreciated that the specific embodiments described herein are merely illustrative of the present invention, and
It is not used in the restriction present invention.
Realization of the invention is described in detail below in conjunction with specific attached drawing:
Fig. 1 shows the modular structure of power circuit provided by one embodiment of the invention, for ease of description, only shows
Part related to the present embodiment, details are as follows:
As shown in Figure 1, power circuit provided by the embodiment of the present invention is connect with load (not shown) comprising whole
Flow bridge 10, voltage changing module 20, power switch tube Q1 and control chip 30.
Wherein, rectifier bridge 10 is connect with voltage changing module 20, voltage changing module 20 and power switch tube Q1, control chip 30 and
Load connection, control chip 30 are connect with power switch tube Q1.
It specifically, rectifier bridge 10 receives alternating current, and is output after direct current to voltage changing module 20 by AC rectification.
The armature winding of voltage changing module 20 carries out energy stores according to the direct current, and will when power switch tube Q1 is disconnected
The energy transmission of storage is to secondary windings, and secondary windings starts to carry out demagnetization to the energy of transmitting, and secondary diode D6 is led at this time
Logical, i.e., secondary windings provides output voltage VO UT to load according to the energy of transmitting under the action of secondary diode D6, with to
Load charging, and when the stopping demagnetization of the secondary windings of voltage changing module 20, secondary diode D6 shutdown.
In addition, the feedback winding of voltage changing module 20 is in the degaussing process of secondary windings according to output voltage VO UT output time
Output voltage VO UT is fed back to control chip 30 by feedback winding by grade coil voltage, and when secondary windings stops demagnetization
When, output voltage VO UT will stop feeding back to control chip 30；Wherein, which refers to feedback winding according to secondary
What the voltage ratio on grade winding obtained, proportionality coefficient is the turn ratio of feedback winding and secondary windings, and at secondary windings
When in degaussing process, the voltage on secondary windings is approximately equal to output voltage VO UT.
The sampled voltage VFB and power switch tube Q1 that control chip 30 receives the feedback winding feedback of voltage changing module 20 is being led
Output electric current CS when logical, and power is controlled according to output electric current CS of the sampled voltage VFB and power switch tube Q1 in conducting
The conducting and shutdown of switching tube Q1, and then realize the constant current constant voltage control of power circuit.
It should be noted that in embodiments of the present invention, transformer 20 refers to including transformer T1 and diode D5, is secondary
Structure including grade diode D6, capacitor C5, resistance R5, resistance R6 and resistance R8, and the specific work process of the structure can
With reference to the prior art, details are not described herein again；In addition, power circuit provided in an embodiment of the present invention further includes by inductance L1, capacitor
The filter module of C1 and capacitor C2 composition, the direct current which mainly exports rectifier bridge 10 is filtered, to disappear
Except the interference signal in direct current.
Further, as shown in Figure 1, control chip 30 includes: output line pressure compensating module 301, sampling and keep module
302, erasing time sampling module 303, error amplification module 304 and drive module 305.
Specifically, sampling and keep module 302, presses compensating module with voltage changing module 20, drive module 305 and output line
301 connections, the driving control signal PUL for being exported according to the sampled voltage VFB and drive module 305 of voltage changing module 20 are produced
Raw sampling keeps voltage VSH, and the load current IOUT adjustment sampling for pressing compensating module 301 to export according to output line keeps voltage
VSH, so that sampling keeps voltage VSH to change with the output voltage VO UT of power circuit.
Wherein, in embodiments of the present invention, load current IOUT refers to the electricity of output end when power circuit connects load
Stream, i.e., power circuit is exported to the electric current of load, which can change with the variation of the output voltage VO UT of power circuit,
And the sampled voltage VFB of transformer 20 is referred to obtained after the secondary coil voltage of the feedback winding of transformer 20 partial pressure
Voltage, which, which is used as, feeds back to control chip 30 to feedback voltage.
Error amplification module 304 is connect with sampling and keep module 302, is adopted for what is generated according to sampling and keep module 302
Sample keeps voltage VSH and received first reference voltage Vref to generate error amplification voltage VEA.Output line presses compensating module
301, it is connect with error amplification module 304 and B voltage changing module 20, for the secondary coil voltage and mistake according to voltage changing module 20
Sampled voltage VFB is adjusted in the error amplification voltage VEA that poor amplification module 304 generates, and defeated according to secondary coil voltage
Load current IOUT out；Wherein, secondary coil voltage relationship proportional to the output voltage VO UT of power circuit.
Wherein, in embodiments of the present invention, since the sampled voltage VFB of transformer 20 is according to the negative of power circuit output end
It carries variation and changes, and the unstable of sampled voltage VFB will have an impact entire power circuit, it is therefore, provided by the invention
In power circuit, control chip 30 presses compensating module 301, sampling and keep module 302 and error amplification module by output line
303 composition compensation loops, so that output line presses compensating module 301 to amplify mould according to the secondary coil voltage and error of transformer 20
Sampled voltage VFB is adjusted in the error amplification voltage VEA that block 304 exports, and the traceable electricity of error amplification voltage VEA
The variation of the output voltage VO UT of source circuit can so effectively eliminate the unstable of sampled voltage VFB and produce to entire power circuit
Raw influence.
Further, since the secondary coil voltage of voltage changing module 20 is that feedback winding is obtained according to the voltage ratio on secondary windings
It arrives, and the voltage on secondary windings is approximately equal to output voltage VO UT in degaussing process, therefore, which can table
Output voltage VO UT is levied, and output voltage VO UT is related to load current IOUT, therefore, output line presses compensating module 301 can basis
The secondary coil voltage obtains load current IOUT.
Erasing time sampling module 303 is connect with voltage changing module 20, for generating the erasing time according to sampled voltage VFB
TDS；Drive module 305 is connect with erasing time sampling module 303, error amplification module 304 and power switch tube Q1, is used
Switching drive signal is generated in the output electric current CS for amplifying voltage VEA, erasing time TDS and power switch tube Q1 according to error
With driving control signal PUL, and according to the switching drive signal driving power switching tube Q1 on or off.
Further, which includes constant current constant voltage control unit 305a, logic control element 305b and drive
Moving cell 305c.
Wherein, the constant current constant voltage control unit 305a and error amplification module 304, erasing time sampling module 303 and
Power switch tube Q1 connection, logic control element 305b are connect with constant current constant voltage control unit 305a, driving unit 305c with
Logic control element 305b connection.
Specifically, constant current constant voltage control unit 305a amplifies voltage VEA, erasing time TDS and function according to according to error
The output electric current CS of rate switching tube Q1 generates switch control signal, and Logic control module 305b generates drive according to switch control signal
Dynamic control signal PUL, drive module 305c generate switching drive signal DRI according to driving control signal PUL, to be driven according to switch
The on or off of dynamic signal DRI control power switch tube Q1.
Wherein, in embodiments of the present invention, since the sampling that sampling and keep module 302 exports keeps voltage VSH can be with electricity
The output voltage VO UT of source circuit changes, i.e., the sampling that sampling and keep module 302 exports keeps voltage VSH that power circuit can be traced
Output voltage VO UT variation, therefore, even if sampling and keep module 302 is defeated except the secondary erasing time of power circuit
Sampling holding voltage VSH out also can reflect the variation of the output voltage VO UT of power circuit, so that error amplification module 304
The variation of the output voltage VO UT of power circuit can be traced in the error amplification voltage VEA of output, so that control chip 30
Compensation loop can also keep stable under underloading, to reduce the output ripple of power circuit.
It should be noted that in embodiments of the present invention, control chip 30 further includes that reference offset module (is not shown in figure
Out), high-low pressure conversion module (not shown) and start-up circuit module (not shown).Due to reference offset module,
The structure and the connection between other modules in control chip 30 of high-low pressure conversion module and start-up circuit module are closed
System is identical with the prior art, and concrete operating principle can refer to the prior art, therefore details are not described herein again.
Further, as a preferred embodiment of the invention, as shown in Fig. 2, sampling and keep module 302 includes: sampling
Time generates unit 302a, switch unit 302b, voltage storage unit 302c and discharge current and generates unit 302d.
Wherein, the sampling time generates unit 302a and voltage changing module 20 (being not shown in the figure, please refer to Fig. 1) and driving mould
Block 305 (being not shown in the figure, please refer to Fig. 1) connection, switch unit 302b and sampling time generate unit 302a and voltage changing module
20 connections, voltage storage cell 302c are connect with switch unit 302b and error amplification module 304, and discharge current generates unit
302d and voltage storage cell 302c, output line pressure compensating module 301 (being not shown in the figure, please refer to Fig. 1) and error amplification
Module 304 connects.
Specifically, the sampling time generates unit 302a according to the sampled voltage VFB of voltage changing module 20, drive module 305
Driving control signal PUL generates sampling time ct；Switch unit 302b is in sampling time ct to the sampling electricity of voltage changing module 20
Pressure VFB is sampled；Voltage storage unit 302c stores the switch unit 302b voltage sampled, is kept with obtaining sampling
Voltage VSH；Discharge current generates unit 302d and generates electric discharge according to the load current IOUT that output line presses compensating module 301 to export
Electric current Id, and sampling is adjusted according to discharge current Id and keeps voltage VSH.
Wherein, in embodiments of the present invention, since the load current IOUT that output line pressure compensating module 301 exports can be with
The variation of the output voltage VO UT of power circuit and change, therefore, discharge current generate unit 302d according to load current IOUT
Generating discharge current Id can change with the variation of the output voltage VO UT of power circuit, therefore, discharge current generates unit
302d may make sampling to keep voltage VSH with electricity when keeping voltage VSH to be adjusted sampling according to discharge current Id
The variation of the output voltage VO UT of source circuit and change.
It should be noted that in embodiments of the present invention, when existing sampling can be used in sampling time generation unit 302a
Between generation circuit realize that particular circuit configurations and working principle can refer to the prior art, details are not described herein again.
In the present embodiment, it keeps end to increase discharge current Id all the way by the sampling in sampling and keep module 302, is used for
The actual conditions of analog sampling voltage holding stage output voltage VO UT, it is ensured that error amplification module (is not shown in the figure, please refers to
Error amplification voltage VEA Fig. 1) exported improves power supply in the variation that also can constantly follow output voltage VO UT at light load
The system stability of circuit.
Further, as a preferred embodiment of the invention, as shown in Fig. 2, discharge current generation unit 302d includes:
Line mends current generation unit 302e and image current subelement 302f.
Wherein, line mends current generation unit 302e and (is not shown in the figure with output line pressure compensating module 301, please refers to figure
1) it connects, image current subelement 302f mends current generation unit 302e and voltage storage cell 302c with line and connect.
Specifically, line mends the load current that current generation unit 302e presses compensating module 301 to export according to output line
IOUT generates line and mends electric current I1, and image current subelement 302f mends electric current I1 according to line and generates discharge current Id, and is put according to this
Electric current Id adjustment sampling keeps voltage VSH.
It should be noted that in embodiments of the present invention, line mends current generation unit 302e can be using electric with load
The current-mirror structure realization that IOUT constitutes image current is flowed, details are not described herein again.
Further, it as a preferred embodiment of the invention, is also wrapped as shown in Fig. 2, discharge current generates unit 302d
Include: zero load determines subelement 302g and switch control subelement 302h.
Wherein, unloaded to determine that subelement 302g is connected with error amplification module 304 (being not shown in the figure, please refer to Fig. 4), it opens
It closes control subelement 302h and determines that subelement 302g and image current subelement 302f is connect with zero load.
Specifically, unloaded determine that subelement 302g amplifies voltage VEA and received second reference voltage Vref1 according to error
Generate it is unloaded determine signal, switch control subelement 302h is when zero load determines signal for power circuit zero load, control mirror image electricity
Subelement 302f is flowed to stop generating discharge current.
In the present embodiment, it is varied less since the output capacitance of power circuit under zero load powers on to be pressed in outside the erasing time,
The sampling that sampling and keep module 302 exports at this time in order to prevent keeps voltage VSH to be far below output voltage VO UT, and then causes to miss
It floats in the output of poor amplification module 304, power circuit of the invention determines that subelement 302g determines that power circuit is by zero load
No work will determine that result is exported to switch control subelement 302h, in order to switch control subelement in light condition
302h shields the discharge current Id under zero load according to decision structure.
Further, as a preferred embodiment of the invention, as shown in figure 3, switch unit 302b includes: sampling resistor
R0 and first switching element SW0.
Wherein, the first end of sampling resistor R0 is connected with voltage changing module 20 (being not shown in the figure, please refer to Fig. 1), sampling electricity
The second end of resistance R0 is connect with the input terminal of first switching element SW0, and the control terminal of first switching element SW0 and sampling time produce
Raw unit 302a connection, the output end of first switching element SW0 are connect with voltage storage cell 302c.
Further, as a preferred embodiment of the invention, as shown in figure 3, voltage storage unit 302c includes energy storage
Capacitor C0.
Wherein, the first end of storage capacitor C0 is connect with switch unit 302b and error amplification module 304, storage capacitor
The second end of C0 is grounded.
Further, as an of the invention preferred embodiment, as shown in figure 3, image current subelement 302f includes: the
Two switch element M0 and third switch element M1.
Wherein, the input terminal of second switch element M0 is mended current generation unit 302e with line and is connect, second switch element
The control terminal of M0 is connect with the control terminal of the input terminal of second switch element M0 and third switch element M1, third switch element
The input terminal of M1 is connect with voltage storage cell 302c, and the output end and switch control subelement 302h of third switch element M1 connects
It connects, the output end ground connection of second switch element M0；It should be noted that image current subelement 302f's shown in Fig. 3 is specific
Structure is to work as power circuit based on there is switch control subelement 302h to determine that subelement 302g is realized with zero load in power circuit
In there is no switch control subelement 302h and unloaded when determining subelement 302g, then the third in image current subelement 302f is opened
The output end of the output end and second switch element M0 that close element M1 is connected to ground altogether.
When it is implemented, second switch element M0 and third switch element M1 are all made of NMOS type transistor realization, it should
Grid, drain electrode and the source electrode of NMOS type transistor be respectively second switch element M0 and third switch element M1 control terminal,
Input terminal and output end.Certainly it will be appreciated by persons skilled in the art that second switch element M0 and third switch element
M1 can also be realized using NPN type triode, PNP type triode, PMOS transistor etc., be not specifically limited herein.
Further, as an of the invention preferred embodiment, as shown in figure 3, it is unloaded determine subelement 302g include than
Compared with device COMP.
Wherein, the first input end of comparator COMP receives the second reference voltage Vref1, the second input of comparator COMP
It holds and is connected in error amplification module 304, the output end of comparator COMP is connect with switch control subelement 302h.
Further, as an of the invention preferred embodiment, as shown in figure 3, switch control subelement 302h includes the
Four switch element M2.
Wherein, the control terminal of the 4th switch element M2 and unloaded judgement subelement 302g, the input of the 4th switch element M2
End is connect with image current subelement 302f, the output end ground connection of the 4th switch element M2.
When it is implemented, the 4th switch element M2 is realized using NMOS type transistor, the grid of the NMOS type transistor, leakage
Pole and source electrode are respectively control terminal, input terminal and the output end of the 4th switch element M2.Certain those skilled in the art can
With understanding, the 4th switch element M2 can also be realized using NPN type triode, PNP type triode, PMOS transistor etc.,
It is not specifically limited herein.
It is former to the work of the control chip 30 in power circuit provided by the present invention by taking circuit shown in Fig. 3 as an example below
Reason illustrates, and details are as follows:
As shown in figure 3, control chip 30 receives the sampling of feedback winding feedback within the secondary erasing time of power circuit
The driving control signal PUL that voltage VFB and drive module 305 export, and according to sampled voltage VFB and driving control signal PUL
Generate sampling time ct.When sampling time ct arrives, first switching element SW0 closure, switch unit 302b is to sampling electricity
It is stored on sampling holding capacitor C0 after pressure VFB sampling.According to the power circuit of the prior art, adopted except the secondary erasing time
Voltage VSH (i.e. sampling keeps voltage) on sample holding capacitor C0 will continue the arrival maintained until the next erasing time, and defeated
Voltage VOUT is after the erasing time out, and due to the presence of load, output voltage VO UT falls under continuing, and keeps so as to cause sampling
Voltage VSH on capacitor C0 outside the erasing time and output voltage VO UT there are biggish deviations.
And the sampling and keep module 302 in the control chip 30 in power circuit provided by the invention in sampling by keeping
Discharge current Id lasting all the way is set on capacitor C0, so that the voltage VSH sampled on holding capacitor C0 will outside the erasing time
Fall under continuing, be similar to the actual conditions of output end voltage VOUT, such as can be seen that existing from waveform diagram shown in Fig. 4
In the power circuit of technology, except the secondary erasing time of power circuit, when output voltage VO UT changes, sampling is protected
The voltage VSH held on capacitor C0 will not change, and power circuit provided by the invention changes as output voltage VO UT
When, the voltage VSH sampled on holding capacitor C0 will change with the variation of output voltage VO UT.When sampling and keep module 302
When the sampling that the variation with output voltage VO UT is changed keeps voltage VSH to export to error amplification module 304, it can make
It obtains the error amplification voltage VEA that error amplification module 304 exports to change with the variation of output voltage VO UT, and then ensures to mend
It repays loop and preferably realizes stabilization.
Further, line mends current generation unit 302e and (is not shown in the figure, please refers to according to output line pressure compensating module
Fig. 1) the load current IOUT exported generates line and mends electric current I1, and it is directly proportional to load current IOUT which mends electric current I1.When line is mended
After current generation unit 302e generates line benefit electric current I1, which mends electric current I1 and flows through second switch element M0, and due to second
Switch element M0 and third switch element M1 is current-mirror structure, and therefore, the electric current and line for flowing through third switch element M1 mend electricity
It is proportional to flow I1, and the electric current for flowing through third switch element M1 is discharge current Id, that is to say, that discharge current Id and line are mended
Electric current I1 is proportional.Mending electric current I1 due to line is obtained according to load current IOUT, discharge current Id and line mend electric current I1 at
Ratio, and load current IOUT can follow the variation of output voltage VO UT, therefore, discharge current Id follows output voltage VO UT's
Change and change, so that sampling keeps the waveform of voltage VSH to change the waveform of approximate output voltage VO UT (such as Fig. 5 institute
Show).
In addition, please also refer to Fig. 1 and Fig. 3, since output capacitance C5 is powered on and is pressed in the erasing time under power circuit zero load
It varies less outside, the sampling that sampling and keep module 302 exports at this time in order to prevent keeps voltage VSH to be far below output voltage
VOUT, and then cause error amplification module 304 to export and float, therefore, it can be put by the error for exporting error amplification module 304
A big voltage VEA and lower second reference voltage Vref1 is compared to judge whether power circuit works in unloaded shape
State, specific deterministic process are as follows:
Comparator COMP receives the error amplification voltage VEA and the second reference voltage that error amplification module 304 exports
Vref1, and the two is compared.When error amplification voltage VEA is greater than the second reference voltage Vref1, comparator COMP is defeated
High level signal out, i.e. comparator COMP determine that power circuit is in non-light condition at this time, and the 4th switch element M2 is led at this time
It is logical；When error amplification voltage VEA is less than the second reference voltage Vref1, comparator COMP exports low level signal, i.e. comparator
COMP determines that power circuit is in light condition at this time, and the 4th switch element M2 is disconnected, and then is shielded to discharge current Id,
It prevents from error amplification module 304 from exporting to float.
It should be noted that in embodiments of the present invention, erasing time sampling module 303, constant current constant voltage control module
The concrete operating principle of 305a, Logic control module 305b and drive module 305c are identical as the prior art, can specifically join
The prior art is examined, details are not described herein again.
In the present embodiment, power circuit provided by the invention is for the loop stability in the case of underloading, by adopting
Sample keeps the end voltage VSH to introduce discharge current Id lasting all the way, and sampling is enabled to keep voltage VSH approximate simulation output electricity
The actual change situation of VOUT is pressed, and then the output situation of error amplification module 304 is made to can reflect secondary output voltage VOUT
Actual conditions, to promote the stabilization of loop.
Further, the present invention also provides a kind of power supply, which includes power circuit.It should be noted that due to
The power circuit of power supply provided by the embodiment of the present invention and Fig. 1 are identical to power circuit shown in Fig. 3, and therefore, the present invention is real
The concrete operating principle for applying the power circuit in power supply provided by example can refer to the detailed description previously with regard to Fig. 1 to Fig. 3,
Details are not described herein again.
In the present invention, mould is sampled by using including output line pressure compensating module, sampling and keep module, erasing time
The control chip of block, error amplification module and drive module, so that the control chip is to the power switch in power circuit
When pipe is controlled, the sampling of sampling and keep module output keeps voltage that can change with the output voltage of power circuit, and then makes
The output of error amplification module is obtained as the output voltage of power circuit changes, to improve the stabilization of control chip compensation loop
Property, reduces the output ripple of power circuit, solves the problems, such as existing power circuit there are output ripples and is big.
The foregoing is merely illustrative of the preferred embodiments of the present invention, is not intended to limit the invention, all in essence of the invention
Made any modifications, equivalent replacements, and improvements etc., should all be included in the protection scope of the present invention within mind and principle.
Claims (10)
1. a kind of power circuit, connected with load, the power circuit include rectifier bridge, voltage changing module, power switch tube and
Chip is controlled, the rectifier bridge is connect with the voltage changing module, the voltage changing module and the power switch tube, the control core
Piece and load connection, the control chip are connect with the power switch tube, which is characterized in that the control chip packet
Include: output line presses compensating module, sampling and keep module, erasing time sampling module, error amplification module and drive module；
The sampling and keep module is connect with the voltage changing module, the drive module and the output line pressure compensating module,
It is kept for generating sampling according to the driving control signal of the sampled voltage of the voltage changing module and drive module output
Voltage, and press the load current of compensating module output to adjust the sampling according to the output line and keep voltage, so that described adopt
Sample keeps voltage to change with the output voltage of the power circuit；
The error amplification module, connect with the sampling and keep module, adopts for what is generated according to the sampling and keep module
Sample keeps voltage and received first reference voltage to generate error amplification voltage；
The output line presses compensating module, connect with the error amplification module and the voltage changing module, for according to
The error amplification voltage that the secondary coil voltage of voltage changing module and the error amplification module generate carries out the sampled voltage
It adjusts, and the load current is exported according to the secondary coil voltage；Wherein, the secondary coil voltage and power supply electricity
The proportional relationship of the output voltage on road；
The erasing time sampling module, connect with the voltage changing module, for generating the erasing time according to the sampled voltage；
The drive module connects with the erasing time sampling module, the error amplification module and the power switch tube
It connects, the output electric current for amplifying voltage, the erasing time and the power switch tube according to the error generates switch
Driving signal and the driving control signal, and drive the power switch tube to be connected or close according to the switching drive signal
It is disconnected.
2. power circuit according to claim 1, which is characterized in that the sampling and keep module includes:
Sampling time generates unit, connect with the voltage changing module and the drive module, for according to the sampled voltage
The sampling time is generated with the driving control signal；
Switch unit generates unit with the sampling time and connect with the voltage changing module, for right within the sampling time
The sampled voltage of the voltage changing module is sampled；
Voltage storage unit is connect with the switch unit and the error amplification module, for adopting to the switch unit
The voltage of sample is stored, and keeps voltage to obtain the sampling；
Discharge current generates unit, amplifies with the voltage storage cell, output line pressure compensating module and the error
Module connection for pressing the load current of compensating module output to generate discharge current according to the output line, and is put according to described
Electric current adjusts the sampling and keeps voltage.
3. power circuit according to claim 2, which is characterized in that the discharge current generates unit and includes:
Line mends current generation unit, connect with output line pressure compensating module, for according to the output line pressure compensation mould
The load current of block output generates line and mends electric current；
Image current subelement mends current generation unit with the line and the voltage storage cell is connect, is used for basis
The line mends electric current and generates the discharge current, and adjusts the sampling according to the discharge current and keep voltage.
4. power circuit according to claim 3, which is characterized in that the discharge current generates unit further include:
Zero load determines subelement, connect with the error amplification module, for according to error amplification voltage and received
Second reference voltage generates unloaded judgement signal；
Switch control subelement is connect with the unloaded judgement subelement and the image current subelement, for described
When zero load determines that signal is the power circuit zero load, controls the image current subelement and stop generating the discharge current.
5. power circuit according to claim 2, which is characterized in that the switch unit includes: sampling resistor and first
Switch element；
The first end of the sampling resistor is connect with the voltage changing module, the second end of the sampling resistor and the first switch
The input terminal of element connects, and the control terminal of the first switching element generates unit with the sampling time and connect, and described first
The output end of switch element is connect with the voltage storage cell.
6. power circuit according to claim 2, which is characterized in that the voltage storage unit includes storage capacitor；
The first end of the storage capacitor is connect with the switch unit and the error amplification module, the storage capacitor
Second end ground connection.
7. power circuit according to claim 3, which is characterized in that the image current subelement includes: second switch
Element and third switch element；
The input terminal of the second switch element is mended current generation unit with the line and is connect, the control of the second switch element
End processed is connect with the control terminal of the input terminal of the second switch element and the third switch element, the third switch member
The input terminal of part is connect with voltage storage cell, the output end of second switch element described in the output end of the third switch element
It is connected to ground altogether.
8. power circuit according to claim 4, which is characterized in that the unloaded judgement subelement includes comparator；
The first input end of the comparator receives second reference voltage, the second input terminal of the comparator and the mistake
Poor amplification module connection, the output end of the comparator are connect with the switch control subelement.
9. power circuit according to claim 4, which is characterized in that the switch control subelement includes the 4th switch member
Part；
The control terminal of 4th switch element and the unloaded judgement subelement, the input terminal of the 4th switch element and institute
State the connection of image current subelement, the output end ground connection of the 4th switch element.
10. a kind of power supply, which is characterized in that the power supply includes power circuit as described in any one of claim 1 to 9.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810166573.XA CN110212766B (en) | 2018-02-28 | 2018-02-28 | Power supply and power supply circuit thereof |
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| CN201810166573.XA CN110212766B (en) | 2018-02-28 | 2018-02-28 | Power supply and power supply circuit thereof |
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| CN110212766A true CN110212766A (en) | 2019-09-06 |
| CN110212766B CN110212766B (en) | 2020-10-23 |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114489216A (en) * | 2022-04-14 | 2022-05-13 | 深圳市赛元微电子有限公司 | Protection circuit applied to LDO (low dropout regulator) |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20050146903A1 (en) * | 2004-01-05 | 2005-07-07 | Ta-Yung Yang | Power-mode controlled power converter |
| CN202340216U (en) * | 2011-11-25 | 2012-07-18 | 浙江商业职业技术学院 | Peak value sampling hold circuit and switching power supply thereof |
| CN102801300A (en) * | 2012-08-30 | 2012-11-28 | 佛山市南海赛威科技技术有限公司 | Primary-side feedback controlled switching power line loss compensating system and method |
| CN103475225A (en) * | 2012-06-06 | 2013-12-25 | 比亚迪股份有限公司 | Switching power supply system and lineal pressure compensation device for switching power supply |
| US20150311778A1 (en) * | 2014-04-24 | 2015-10-29 | Richtek Technology Corporation | Flyback power converter and control circuit and control method thereof |
-
2018
- 2018-02-28 CN CN201810166573.XA patent/CN110212766B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20050146903A1 (en) * | 2004-01-05 | 2005-07-07 | Ta-Yung Yang | Power-mode controlled power converter |
| CN202340216U (en) * | 2011-11-25 | 2012-07-18 | 浙江商业职业技术学院 | Peak value sampling hold circuit and switching power supply thereof |
| CN103475225A (en) * | 2012-06-06 | 2013-12-25 | 比亚迪股份有限公司 | Switching power supply system and lineal pressure compensation device for switching power supply |
| CN102801300A (en) * | 2012-08-30 | 2012-11-28 | 佛山市南海赛威科技技术有限公司 | Primary-side feedback controlled switching power line loss compensating system and method |
| US20150311778A1 (en) * | 2014-04-24 | 2015-10-29 | Richtek Technology Corporation | Flyback power converter and control circuit and control method thereof |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114489216A (en) * | 2022-04-14 | 2022-05-13 | 深圳市赛元微电子有限公司 | Protection circuit applied to LDO (low dropout regulator) |
| CN114489216B (en) * | 2022-04-14 | 2022-06-24 | 深圳市赛元微电子有限公司 | Protection circuit applied to LDO (low dropout regulator) |
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| CN110212766B (en) | 2020-10-23 |
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