CN208890638U - A kind of compensation circuit - Google Patents
A kind of compensation circuit Download PDFInfo
- Publication number
- CN208890638U CN208890638U CN201821580486.0U CN201821580486U CN208890638U CN 208890638 U CN208890638 U CN 208890638U CN 201821580486 U CN201821580486 U CN 201821580486U CN 208890638 U CN208890638 U CN 208890638U
- Authority
- CN
- China
- Prior art keywords
- circuit units
- control
- compensation circuit
- voltage
- compensation
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Landscapes
- Continuous-Control Power Sources That Use Transistors (AREA)
Abstract
The utility model relates to a kind of compensation circuits, for providing compensation for the feedback pin FB of control IC, it is characterised in that: including detecting signal unit and compensation circuit units；Detecting signal unit is used to detect the voltage of control IC power port VDD, when the voltage is higher than setting value, detecting signal unit outputs control signals to the control terminal of compensation circuit units, control compensation circuit units are started to work, the input terminal input offset signal for compensating circuit units at this time, the output end output thermal compensation signal for compensating circuit units are used to draw high the level for the feedback pin FB for controlling IC.The output abnormality problem that the utility model circuit is simple, cost of implementation is low, has innovatively evaded low-voltage input lower power module when carrying out load switching with capacitive load.
Description
Technical field
The utility model relates to a kind of compensation circuits, in particular to compensate in Switching Power Supply to control IC feedback foot
Compensation circuit.
Background technique
It is as shown in Figure 1 the traditional part control IC peripheral circuit in Switching Power Supply, IC1 therein is to control IC,
The peripheral circuit of IC1 is by isolation feedback optocoupler OC1, resistance R1, capacitor C1, power supply winding L1, diode D1, capacitor C2, capacitor
C3 composition, control IC pin are described as follows:
VIN: input voltage measurement foot, settable UVP protection (under voltage protection, Chinese are as follows:
Under-voltage protection) and feedforward compensation；
VDD: power port is used for input control IC supply voltage；
FB: Voltage Feedback foot is used for fed-back output voltage signal；
GATE: switching tube drive output mouth；
CS: current sample input port；
GND: control IC is with reference to ground；
BOS: boosting pin constitutes BOOST circuit with peripheral circuit, and output square-wave signal control BOOST circuit will input
Boost in voltage enables the power port VDD of IC1 to reach unlatching value under low pressure；
RI: frequency sets pin, outer connecting resistance to the settable working frequency in ground.
The prior art is generally arranged control IC feedback foot FB and slowly rises during opening machine to improve booting overshoot, i.e., soft
Starting feeds back foot FB at this time and participates in control soft start, and feedback foot FB is the external pin for controlling IC soft start unit.Open machine process
In, in some cycles (hereinafter referred to as time-count cycle), if the level of feedback foot FB fails normally to rise, soft start failure,
Usually control IC will be considered that operation irregularity at this time, and enter guard mode.When output band capacitive load, if load is from heavy duty to light
Jump is carried, then output voltage maintains setting value or more for a long time, to control IC feedback foot FB by pumping electricity to low level, and stops
Only switching tube drives.In Switching Power Supply, the power supply for controlling IC generally uses transformer winding to power, therefore controls the electricity of IC
Source port VDD powers in unpowered source during switching tube driving stops, and is only maintained by storage capacitor.When input voltage is less than control
When the low pressure of IC power port VDD under-voltage protection value processed, control IC power port vdd voltage can drop to under-voltage protection value, electricity
Road is designed as control IC and opens machine again, needs to carry out soft start again at this time, and controls IC feedback foot FB and still take out electricity by output,
Can not normally it rise in time-count cycle, soft start failure, IC enters guard mode, and output is abnormal therewith.
For above situation, the mode for increasing IC power port VDD storage capacitor or winding voltage of powering can be generally taken
Control IC is avoided to carry out soft start again because supply port VDD is under-voltage.Even if this mode it is maximum the disadvantage is that system have compared with
Fast response speed, the time for exporting lasting pumping electricity IC feedback foot FB is still very long, IC power port VDD storage capacitor theory meter
Calculation value reaches 10uF rank, this for product miniaturization and it is cost effective be all unfavorable.Big storage capacitor also can band simultaneously
Carry out the longer starting-up delay time.
Utility model content
In view of this, can be weighed after controlling the under-voltage protection of IC power port the utility model proposes a kind of compensation circuit
Control IC feedback foot FB is compensated in the time-count cycle opened, to enable to control the normal soft start of IC, avoids control IC
Enter by mistake through guard mode.
The utility model is achieved through the following technical solutions:
A kind of compensation circuit, for providing compensation for the feedback pin FB of control IC, it is characterised in that: including signal detection
Unit and compensation circuit units；Detecting signal unit is used to detect the voltage of control IC power port VDD, sets when the voltage is higher than
When definite value, detecting signal unit outputs control signals to the control terminal of compensation circuit units, and control compensation circuit units start work
Make, compensate the input terminal input offset signal of circuit units at this time, the output end output thermal compensation signal for compensating circuit units is used for
Draw high the level of the feedback pin FB of control IC.
Preferably, the input terminal connection power port VDD for compensating circuit units, using the voltage of power port VDD as benefit
Repay signal.
As detecting signal unit and the first specific embodiment of compensation circuit units, detecting signal unit is steady
Diode D1 is pressed, compensation circuit units include zener diode D1 and current-limiting resistance R1, and the anode of zener diode D1 is for connecting
The feedback pin FB of control IC is met, one end of the cathode connection current-limiting resistance R1 of zener diode D1, current-limiting resistance R1's is another
End is for connecting the power port VDD of control IC.
As detecting signal unit and the equivalent replacement for the first specific embodiment for compensating circuit units, signal inspection
Survey unit is zener diode D1, and compensation circuit units include zener diode D1 and current-limiting resistance R1, zener diode D1's
Cathode is used to connect the power port VDD of control IC, one end of the anode connection current-limiting resistance R1 of zener diode D1, current limliting electricity
The other end of resistance R1 is used to connect the feedback pin FB of control IC.
Include as detecting signal unit and second of specific embodiment of compensation circuit units, detecting signal unit
Divider resistance R1 and R2, compensation circuit units include current-limiting resistance R3, NPN triode Q1 and voltage-stabiliser tube D1；Divider resistance R1 and
One end is used to be connected to the ground for connection control IC power port VDD, the other end after R2 series connection, the connection of divider resistance R1 and R2
The control terminal of point connection compensation circuit units；One end of current-limiting resistance R3 is the input terminal for compensating circuit units, current-limiting resistance R3
The other end connection NPN triode Q1 collector, the ground level of NPN triode Q1 be compensation circuit units control terminal, NPN tri-
The transmitting of pole pipe Q1 extremely compensates the output end of circuit units, and the cathode of voltage-stabiliser tube D1 connects the emitter of NPN triode Q1, surely
The anode of pressure pipe D1 is connected to the ground.
As detecting signal unit and the equivalent replacement for second of specific embodiment for compensating circuit units, signal inspection
Surveying unit includes divider resistance R1 and R2, and compensation circuit units include current-limiting resistance R3, NPN triode Q1 and voltage-stabiliser tube D1；Point
One end is used to be connected to the ground for connection control IC power port VDD, the other end after piezoresistance R1 and R2 series connection, divider resistance R1
The control terminal of compensation circuit units is connected with the tie point of R2；The current collection of NPN triode Q1 extremely compensates the input of circuit units
End, the base stage of NPN triode Q1 are to compensate the control terminal of circuit units, and the emitter of NPN triode Q1 connects current-limiting resistance R3
One end, the other end of current-limiting resistance R3 is the output end for compensating circuit units, and the cathode connection compensation circuit of voltage-stabiliser tube D1 is single
The output end of member, the anode of voltage-stabiliser tube D1 are connected to the ground.
Include as detecting signal unit and the third specific embodiment of compensation circuit units, detecting signal unit
Divider resistance R1, R2 and three terminal regulator IC2, compensation circuit units are PNP triode Q1；Divider resistance R1 and R2 series connection are latter
For connecting control IC power port VDD, the other end for being connected to the ground, the reference foot of three terminal regulator IC2 connects partial pressure at end
The tie point of resistance R1 and R2, the anode of three terminal regulator IC2 are connected to the ground, and the cathode connection of three terminal regulator IC2 compensates back
The control terminal of road unit；The transmitting of PNP triode Q1 extremely compensates the input terminal of circuit units, and the base stage of PNP triode Q1 is
The control terminal of circuit units is compensated, the current collection of PNP triode Q1 extremely compensates the output end of circuit units.
The preferred embodiment of the third specific embodiment as compensation circuit units, compensates the input terminal of circuit units
It is also used for connection control IC power port VDD.
Include as detecting signal unit and the 4th kind of specific embodiment of compensation circuit units, detecting signal unit
Divider resistance R1, R2, three terminal regulator IC2 and PNP triode Q1, compensation circuit units are NPN triode Q2；Divider resistance R1
With one end after R2 series connection for connection control IC power port VDD, the other end for being connected to the ground, the ginseng of three terminal regulator IC2
The tie point of foot connection divider resistance R1 and R2 is examined, the anode of three terminal regulator IC2 is connected to the ground, the yin of three terminal regulator IC2
Pole connects the base stage of PNP triode Q1, and the emitter of PNP triode Q1 is also used for connection control IC power port VDD, PNP tri-
The control terminal of the collector connection compensation circuit units of pole pipe Q1；The current collection of PNP triode Q2 extremely compensates the defeated of circuit units
Enter end, the base stage of PNP triode Q2 is to compensate the control terminal of circuit units, and the transmitting of PNP triode Q2 extremely compensates circuit list
The output end of member.
Include as detecting signal unit and the 5th kind of specific embodiment of compensation circuit units, detecting signal unit
Divider resistance R1, R2, three terminal regulator IC2 and NPN triode Q1, compensation circuit units are PNP triode Q2；Divider resistance R1
With one end after R2 series connection for connection control IC power port VDD, the other end for being connected to the ground, the ginseng of three terminal regulator IC2
The tie point of foot connection divider resistance R1 and R2 is examined, the anode of three terminal regulator IC2 is connected to the ground, the yin of three terminal regulator IC2
Pole connects the emitter of PNP triode Q1, and the base stage of PNP triode Q1 is also used for connection control IC power port VDD, PNP tri-
The control terminal of the collector connection compensation circuit units of pole pipe Q1；The transmitting of PNP triode Q2 extremely compensates the defeated of circuit units
Enter end, the base stage of PNP triode Q2 is to compensate the control terminal of circuit units, and the current collection of PNP triode Q2 extremely compensates circuit list
The output end of member.
The working principle of the utility model is as follows: under the conditions of output band capacitive load, if load is jumped from heavy duty to underloading,
Then output voltage maintains setting value or more for a long time, so that controlling IC feedback foot FB is taken out electricity to low level, and shutdown switch
Pipe driving.In Switching Power Supply, the power supply for controlling IC generally uses transformer winding to power, therefore controls the power port of IC
VDD powers in unpowered source during switching tube driving stops, and is only maintained by storage capacitor.When input voltage is less than control IC electricity
When the low pressure of source port VDD under-voltage protection value, control IC power port vdd voltage can drop to under-voltage protection value.At this point, circuit
On be designed as control IC open machine again, pass through control IC boosting pin BOS export square-wave signal control IC inside BOOST electricity
Input voltage is boosted on road, and the power port VDD for controlling IC is made to reach unlatching value again, then controls IC and re-starts soft open
It is dynamic.Controlling IC is clocked into the period simultaneously, and the BOS foot that IC is controlled within time-count cycle can export square wave to maintain control IC power supply
Port vdd voltage avoids it repeatedly under-voltage, at this time control IC power port VDD with low-voltage return difference maintain VDD unlatching value with
Under.If without the utility model circuit, in soft start control IC feedback foot FB by output feed back take out electricity, soft start failure, IC into
Enter guard mode.The utility model is established by detection control IC power port VDD high voltage feeds back foot FB's to control IC
Channel is compensated, to control IC feedback foot FB feed in above-mentioned soft start-up process again, so that soft start successfully completes, timing week
Vdd voltage is restored to steady state working voltage range after system normal transient to light condition in phase, is not enough to control compensation circuit
Work, therefore control IC feedback foot FB feed is stopped, it is not involved in feedback signal adjusting.
The utility model is compensated using voltage under the specific condition of system foot position as control, has following significant spy
Point:
1, the utility model efficiently avoids controlling IC false triggering guard mode under above-mentioned load disturbance, and system exports just
Often；
2, the utility model only compensates under the special high pressure of VDD, on system without influence when systematic steady state works；
3, the utility model is compensated using system power itself source, dramatically saves peripheral circuit, circuit arrangement
It is simple easily to realize.
Detailed description of the invention
Fig. 1 is the traditional part control IC peripheral circuit；
Fig. 2 is that the function of the utility model realizes block diagram；
Fig. 3 is first case study on implementation of the utility model；
Fig. 4 is second case study on implementation of the utility model；
Fig. 5 is the third case study on implementation of the utility model；
Fig. 6 is the 4th case study on implementation of the utility model；
Fig. 7 is the 5th case study on implementation of the utility model.
Specific embodiment
Fig. 2 is that the function of the utility model realizes that block diagram, the circuit block diagram include that detecting signal unit and compensation circuit are single
Member；The input terminal of detecting signal unit is used to connect the power port VDD of control IC, and the output end of detecting signal unit, which connects, to be mended
The control terminal for repaying circuit units compensates the input terminal of circuit units for connecting compensation source, and the output end for compensating circuit units is used
In the feedback pin FB of connection control IC.
Fig. 2 is that the function of the utility model standard realizes block diagram, when detecting signal unit and compensation circuit units use not
After same specific implementation circuit, multiplexing and series circuit exchange position due to component do not influence the presence of the situations such as function,
This will will lead to function and realizes that the connection type of block diagram can change, and such situation can be found in specific embodiment, herein not
It draws one by one.
The utility model of the application is contemplated that relatively high when certain loads jump using the power port VDD of control IC
Pressure as control signal, control compensation circuit soft start unit is compensated, guarantee certain loads jump when soft start at
Function carries out, and to avoid false triggering from controlling IC false triggering guard mode, so that output be maintained to stablize, has evaded the lower electricity of low-voltage input
Source module carries out output abnormality problem when load switching with capacitive load, while compensating need to be in control signal and compensation power supply source
It just will do it (time-count cycle as the above-mentioned) when existing simultaneously, the work of system normal steady state do not had an impact.
In order to enable those skilled in the art better understood when the application, below by way of specific embodiment into
Row explanation.
First embodiment
Fig. 3 shows the first case study on implementation of the utility model application.
Detecting signal unit in the present embodiment is zener diode D1, compensation circuit units include zener diode D1 and
The feedback pin FB of the anode connection control IC of current-limiting resistance R1, zener diode D1, the cathode of zener diode D1 connect electricity
Hinder one end of R1, the power port VDD of the other end connection control IC of resistance R1.
The cathode of the present embodiment zener diode D1 is the input terminal of detecting signal unit, and the anode of zener diode D1 is
The output end of detecting signal unit；Zener diode D1 is multiplexed in detecting signal unit and compensation circuit units, electricity
The other end of resistance R1 is the input terminal for compensating circuit units, and the cathode of zener diode D1 is the control terminal for compensating circuit units,
The anode of zener diode D1 is the output end for compensating circuit units；The compensation source of the input terminal input of compensation circuit units is exactly
Control the voltage of the power port VDD of IC.
The working principle of the present embodiment is identical as the analysis of utility model content part, herein only for detecting signal unit
It is described as follows with the working principle of compensation circuit units circuit:
When control IC power port vdd voltage because control BOOST circuit boosts, reach zener diode D1 both end voltage
Start pressure stabilizing to breakdown reverse voltage, while current-limiting resistance R1 and D1 pairs of zener diode are passed through by control IC power port VDD
Control IC feedback foot FB is compensated, and passes through the size of the adjustable compensation electric current of current-limiting resistance R1.This compensation promotes soft open
It moves successfully, system is transitioned into underloading.Control IC is exited time-count cycle at this time, and BOS foot stops square-wave signal and exports, under vdd voltage
Voltage-stabiliser tube D1 breakdown reverse voltage is down to hereinafter, compensation stops.
The present embodiment have following 4 the utility model has the advantages that
1, circuit is simple, and device cost is low；
2, the voltage that control compensation circuit units are started to work can be according to voltage-stabiliser tube characteristic careful design；
3, specific foot position particular job state compensates, and does not bring a negative impact to system worked well；
4, the strong port VDD of compensation circuit units feeder ear selection power supply capacity, has biggish compensation ability.
It should be noted that the present embodiment takes control IC power port VDD for control signal, for vdd voltage under stable state
Design need to avoid compensation circuit work when control signal voltage.
In addition, the present embodiment zener diode D1 and current-limiting resistance R1 is series connection, the two can exchange position, equally can be real
Existing purpose of utility model.
Second embodiment
Fig. 4 shows the second case study on implementation of the utility model application.
Detecting signal unit in the present embodiment includes divider resistance R1 and R2；Compensating circuit units includes current-limiting resistance
R3, NPN triode Q1 and voltage-stabiliser tube D1；One end of current-limiting resistance R3 connects compensation source SFB, and the other end connects NPN triode Q1
Collector, NPN triode Q1 ground level connection divider resistance R1 and R2 tie point, NPN triode Q1 emitter connection
The feedback pin FB of IC, the feedback pin FB of the cathode connection control IC of voltage-stabiliser tube D1 are controlled, anode is connected to the ground, divider resistance
One end of R1 connects power port VDD, and the other end connects the ground level of NPN triode Q1, and one end of divider resistance R2 is connected to the ground,
The ground level of other end connection NPN triode Q1.
One end of divider resistance R1 is the input terminal of detecting signal unit, and the other end of divider resistance R1 and one end of R2 are
The output end of detecting signal unit, one end of current-limiting resistance R3 are the input terminal for compensating circuit units, the base stage of NPN triode Q1
For the control terminal for compensating circuit units, the transmitting of NPN triode Q1 extremely compensates the output end of circuit units.
The working principle of the present embodiment is identical as the analysis of utility model content part, herein only for detecting signal unit
It is described as follows with the working principle of compensation circuit units circuit:
The base voltage of NPN triode Q1 is that divider resistance R1 and R2 divides control IC power port VDD, works as electricity
Source port vdd voltage is made NPN triode Q1 emitter junction reach conducting voltage conducting, is compensated at this time by control BOOST circuit boosting
Source SFB feeds back foot to control IC by NPN triode Q1 and provides FB compensation, by adjusting the adjustable benefit of current-limiting resistance R3 parameter
The size of electric current is repaid, voltage-stabiliser tube D1 is reversed when controlling the voltage of feedback pin FB of IC and rising in setting value in compensation process
Breakdown shunts, and plays the role of limiting voltage.This compensation promotes soft start success, and system is transitioned into underloading.IC is controlled at this time
It exits time-count cycle, BOS foot stops square-wave signal output, and vdd voltage decline, so that NPN triode Q1 turns off, compensation stops.
The present embodiment equally has 4 beneficial effects of above-mentioned first embodiment, and this will not be repeated here.
In addition, both the present embodiment triode Q1 and current-limiting resistance R3 can exchange position, it is equally able to achieve utility model
Purpose.
3rd embodiment
Fig. 5 shows the third case study on implementation of the utility model application.
Detecting signal unit in the present embodiment includes divider resistance R1, R2 and three terminal regulator IC2；Compensate circuit units
For PNP triode Q1；The emitter of PNP triode Q1 connects power port VDD, and the collector of PNP triode Q1 connects control
The cathode of the base stage connection three terminal regulator IC2 of the feedback pin FB of IC, PNP triode Q1, the anode of three terminal regulator IC2 connect
It is connected to ground, one end of the connection of reference foot the divider resistance R1 and R2 of three terminal regulator IC2, the divider resistance R1 other end is connected to electricity
Source port VDD, the divider resistance R2 other end are connected to the anode of three terminal regulator IC2.
The other end of divider resistance R1 is the input terminal of detecting signal unit, and the cathode of three terminal regulator IC2 is signal inspection
The output end of unit is surveyed, the transmitting of PNP triode Q1 extremely compensates the input terminal of circuit units, and the base stage of NPN triode Q1 is
The control terminal of circuit units is compensated, the current collection of PNP triode Q1 extremely compensates the output end of circuit units.
The working principle of the present embodiment is identical as the analysis of utility model content part, herein only for detecting signal unit
It is described as follows with the working principle of compensation circuit units circuit:
The reference foot voltage of three terminal regulator IC2 is that divider resistance R1 and R2 divides power port VDD, works as power supply
Port vdd voltage is caused the reference foot voltage of IC2 that will be elevated, is higher than IC2 internal reference by control BOOST circuit boosting
When voltage, the reference foot that electric current flows into IC2 is begun with, PNP triode Q1 is begun to turn at this time, and then passes through power port VDD
Compensation is provided to control IC feedback foot FB, by adjusting the size of the adjustable compensation electric current of divider resistance R1 and R2 parameter.This
Kind compensation promotes soft start success, and system is transitioned into underloading.Control IC is exited time-count cycle at this time, and BOS foot stops square-wave signal
Output, vdd voltage decline, the reference foot voltage of three terminal regulator IC2 will decline, when being lower than IC2 internal reference voltage, electric current
The cathode of three terminal regulator IC2 is stopped flow into, and then PNP triode Q1 is turned off, stops compensation.
The present embodiment equally has 4 beneficial effects of above-mentioned first embodiment, and this will not be repeated here.
Explanation is also needed, the present embodiment takes control IC power port VDD for control signal, for VDD under stable state
The design of voltage needs to avoid control signal voltage when compensation circuit work.
Fourth embodiment
Fig. 6 shows the 4th case study on implementation of the utility model application.
Detecting signal unit in the present embodiment includes divider resistance R1, R2, three terminal regulator IC2 and PNP triode Q1；
Compensation circuit units are NPN triode Q2；The emitter of PNP triode Q1 connects power port VDD, the collection of PNP triode Q1
Electrode connects the base stage of NPN triode Q2, the cathode of the base stage connection three terminal regulator IC2 of PNP triode Q1；NPN triode
The feedback pin FB of the emitter connection control IC of Q2, the collector of NPN triode Q2 connect compensation source SFB；Three terminal regulator
The anode of IC2 is connected to ground, and the reference foot of three terminal regulator IC2 connects one end of divider resistance R1 and R2, and divider resistance R1 is another
One end is connected to power port VDD, and the divider resistance R2 other end is connected to the anode of IC2.
The other end of divider resistance R1 is the input terminal of detecting signal unit, and the current collection of PNP triode Q1 extremely signal is examined
The output end of unit is surveyed, the transmitting of PNP triode Q1 extremely compensates the input terminal of circuit units, and the base stage of NPN triode Q2 is
The control terminal of circuit units is compensated, the transmitting of NPN triode Q2 extremely compensates the output end of circuit units.
The working principle of the present embodiment is identical as the analysis of utility model content part, herein only for detecting signal unit
It is described as follows with the working principle of compensation circuit units circuit:
The reference foot voltage of three terminal regulator IC2 is that divider resistance R1 and R2 divides power port VDD, works as power supply
Port vdd voltage is caused the reference foot voltage of three terminal regulator IC2 that will be elevated, is higher than three by control BOOST circuit boosting
When holding voltage-stablizer IC2 internal reference voltage, the cathode that electric current flows into IC2 is begun with, PNP triode Q1 is begun to turn at this time, NPN
Triode Q2 is also begun to turn on, and then is fed back foot to control IC by compensation source SFB and provided FB compensation, by adjusting divider resistance
The size of R1 and the adjustable compensation electric current of R2 parameter.This compensation promotes soft start success, and system is transitioned into underloading.This time control
IC processed is exited time-count cycle, and BOS foot stops square-wave signal output, vdd voltage decline, the reference foot voltage of three terminal regulator IC2
It will decline, when being lower than three terminal regulator IC2 internal reference voltage, electric current stops flow into the cathode of three terminal regulator IC2, in turn
PNP triode Q1 and NPN triode Q2 shutdown, stops compensation.
The present embodiment equally has 4 beneficial effects of above-mentioned first embodiment, and this will not be repeated here.
5th embodiment
Fig. 7 shows the 5th case study on implementation of the utility model application.
Detecting signal unit in the present embodiment includes divider resistance R1, R2, three terminal regulator IC2 and NPN triode Q1；
Compensation circuit units are PNP triode Q2；The cathode of the emitter connection connection three terminal regulator IC2 of NPN triode Q1, NPN
The base stage of the collector connection PNP triode Q2 of triode Q1, the base stage of NPN triode Q1 connect power port VDD；PNP tri-
The feedback pin FB of the collector connection control IC of emitter connection connection the compensation source SFB, PNP triode Q2 of pole pipe Q2；Three
The anode of end voltage-stablizer IC2 is connected to ground, one end of the connection of reference foot the divider resistance R1 and R2 of three terminal regulator IC2, partial pressure
The resistance R1 other end is connected to power port VDD, and the divider resistance R2 other end is connected to the anode of three terminal regulator IC2.
The other end of divider resistance R1 is the input terminal of detecting signal unit, and the current collection of NPN triode Q1 extremely signal is examined
The output end of unit is surveyed, the base stage of NPN triode Q2 is to compensate the control terminal of circuit units, and the transmitting of NPN triode Q2 is extremely
The input terminal of circuit units is compensated, the current collection of NPN triode Q2 extremely compensates the output end of circuit units.
The working principle of the present embodiment is identical as the analysis of utility model content part, herein only for detecting signal unit
It is described as follows with the working principle of compensation circuit units circuit:
The reference foot voltage of three terminal regulator IC2 is that divider resistance R1 and R2 divides power port VDD, works as power supply
Port vdd voltage boosts because controlling BOOST circuit, causes the reference foot voltage of three terminal regulator IC2 that will be elevated, is higher than
When three terminal regulator IC2 internal reference voltage, the cathode that electric current flows into three terminal regulator IC2 is begun with, at this time NPN triode Q1
It beginning to turn on, control PNP triode Q2 is also begun to turn on, and then is fed back foot to control IC by compensation source SFB and provided FB compensation,
By adjusting the size of the adjustable compensation electric current of divider resistance R1 and R2 parameter.This compensation promotes soft start success, system
It is transitioned into underloading.Control IC is exited time-count cycle at this time, and BOS foot stops square-wave signal output, vdd voltage decline, three-terminal voltage-stabilizing
The reference foot voltage of device IC2 will decline, and when being lower than three terminal regulator IC2 internal reference voltage, it is steady that electric current stops flow into three ends
The cathode of depressor IC2, and then NPN triode Q1, PNP triode Q2 are turned off, and stop compensation.
The present embodiment equally has 4 beneficial effects of above-mentioned first embodiment, and this will not be repeated here.
It should be pointed out that above-mentioned preferred embodiment is not construed as limitations of the present invention, this technology is led
For the those of ordinary skill in domain, without departing from the spirit and scope of the utility model, several improvement and profit can also be made
Decorations, are also able to achieve the purpose of this utility model, these improvements and modifications also should be regarded as the protection scope of the utility model, this is practical
Novel protection scope should be defined by the scope defined by the claims..
Claims (10)
1. a kind of compensation circuit, for providing compensation for the feedback pin FB of control IC, it is characterised in that: including signal detection list
Member and compensation circuit units；Detecting signal unit is used to detect the voltage of control IC power port VDD, when the voltage is higher than setting
When value, detecting signal unit outputs control signals to the control terminal of compensation circuit units, and control compensation circuit units are started to work,
The input terminal input offset signal for compensating circuit units at this time compensates the output end output thermal compensation signal of circuit units for drawing high
Control the level of the feedback pin FB of IC.
2. compensation circuit according to claim 1, it is characterised in that: compensate the input terminal connection power port of circuit units
VDD, using the voltage of power port VDD as thermal compensation signal.
3. compensation circuit according to claim 1, it is characterised in that: detecting signal unit is zener diode D1, compensation
Circuit units include zener diode D1 and current-limiting resistance R1, and the feedback that the anode of zener diode D1 is used to connect control IC is drawn
One end of the cathode connection current-limiting resistance R1 of foot FB, zener diode D1, the other end of current-limiting resistance R1 is for connecting control IC
Power port VDD.
4. compensation circuit according to claim 1, it is characterised in that: detecting signal unit is zener diode D1, compensation
Circuit units include zener diode D1 and current-limiting resistance R1, and the cathode of zener diode D1 is used to connect the power end of control IC
One end of the anode connection current-limiting resistance R1 of mouth VDD, zener diode D1, the other end of current-limiting resistance R1 is for connecting control IC
Feedback pin FB.
5. compensation circuit according to claim 1, it is characterised in that: detecting signal unit includes divider resistance R1 and R2,
Compensating circuit units includes current-limiting resistance R3, NPN triode Q1 and voltage-stabiliser tube D1；One end is used for after divider resistance R1 and R2 series connection
For being connected to the ground, it is single that divider resistance R1 connects compensation circuit with the tie point of R2 for connection control IC power port VDD, the other end
The control terminal of member；One end of current-limiting resistance R3 is the input terminal for compensating circuit units, and the other end of current-limiting resistance R3 connects NPN tri-
The collector of pole pipe Q1, the ground level of NPN triode Q1 are the control terminal for compensating circuit units, and the transmitting of NPN triode Q1 is extremely
Compensate the output end of circuit units, the emitter of the cathode connection NPN triode Q1 of voltage-stabiliser tube D1, the anode connection of voltage-stabiliser tube D1
To ground.
6. compensation circuit according to claim 1, it is characterised in that: detecting signal unit includes divider resistance R1 and R2,
Compensating circuit units includes current-limiting resistance R3, NPN triode Q1 and voltage-stabiliser tube D1；One end is used for after divider resistance R1 and R2 series connection
For being connected to the ground, it is single that divider resistance R1 connects compensation circuit with the tie point of R2 for connection control IC power port VDD, the other end
The control terminal of member；The current collection of NPN triode Q1 extremely compensates the input terminal of circuit units, and the base stage of NPN triode Q1 is compensation
The control terminal of circuit units, one end of the emitter connection current-limiting resistance R3 of NPN triode Q1, the other end of current-limiting resistance R3 are
The output end of circuit units, the output end of the cathode connection compensation circuit units of voltage-stabiliser tube D1 are compensated, the anode of voltage-stabiliser tube D1 connects
It is connected to ground.
7. compensation circuit according to claim 1, it is characterised in that: detecting signal unit include divider resistance R1, R2 and
Three terminal regulator IC2, compensation circuit units are PNP triode Q1；One end is for connecting control after divider resistance R1 and R2 series connection
IC power port VDD, the other end are for being connected to the ground, the company of the connection of reference foot the divider resistance R1 and R2 of three terminal regulator IC2
The anode of contact, three terminal regulator IC2 is connected to the ground, the control terminal of the cathode connection compensation circuit units of three terminal regulator IC2；
The transmitting of PNP triode Q1 extremely compensates the input terminal of circuit units, and the base stage of PNP triode Q1 is to compensate the control of circuit units
End processed, the current collection of PNP triode Q1 extremely compensate the output end of circuit units.
8. compensation circuit according to claim 7, it is characterised in that: the input terminal for compensating circuit units is also used for connection control
IC power port VDD processed.
9. compensation circuit according to claim 1, it is characterised in that: detecting signal unit includes divider resistance R1, R2, and three
Voltage-stablizer IC2 and PNP triode Q1 is held, compensation circuit units are NPN triode Q2；One end is used after divider resistance R1 and R2 series connection
In connection control IC power port VDD, the other end for being connected to the ground, the reference foot of three terminal regulator IC2 connects divider resistance
The anode of the tie point of R1 and R2, three terminal regulator IC2 is connected to the ground, and the cathode of three terminal regulator IC2 connects PNP triode Q1
Base stage, the emitter of PNP triode Q1 be also used for connection control IC power port VDD, PNP triode Q1 collector connection
Compensate the control terminal of circuit units；The current collection of PNP triode Q2 extremely compensates the input terminal of circuit units, PNP triode Q2's
Base stage is to compensate the control terminal of circuit units, and the transmitting of PNP triode Q2 extremely compensates the output end of circuit units.
10. compensation circuit according to claim 1, it is characterised in that: detecting signal unit includes divider resistance R1, R2,
Three terminal regulator IC2 and NPN triode Q1, compensation circuit units are PNP triode Q2；One end after divider resistance R1 and R2 series connection
For connecting control IC power port VDD, the other end for being connected to the ground, the reference foot connection of three terminal regulator IC2 divides electricity
The tie point of R1 and R2 is hindered, the anode of three terminal regulator IC2 is connected to the ground, and the cathode of three terminal regulator IC2 connects PNP triode
The emitter of Q1, the collector that the base stage of PNP triode Q1 is also used for connection control IC power port VDD, PNP triode Q1 connect
Connect the control terminal of compensation circuit units；The transmitting of PNP triode Q2 extremely compensates the input terminal of circuit units, PNP triode Q2
Base stage be to compensate the control terminal of circuit units, the current collection of PNP triode Q2 extremely compensates the output end of circuit units.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201821580486.0U CN208890638U (en) | 2018-09-27 | 2018-09-27 | A kind of compensation circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201821580486.0U CN208890638U (en) | 2018-09-27 | 2018-09-27 | A kind of compensation circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN208890638U true CN208890638U (en) | 2019-05-21 |
Family
ID=66514133
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201821580486.0U Active CN208890638U (en) | 2018-09-27 | 2018-09-27 | A kind of compensation circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN208890638U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109194109A (en) * | 2018-09-27 | 2019-01-11 | 广州金升阳科技有限公司 | A kind of compensation circuit |
-
2018
- 2018-09-27 CN CN201821580486.0U patent/CN208890638U/en active Active
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109194109A (en) * | 2018-09-27 | 2019-01-11 | 广州金升阳科技有限公司 | A kind of compensation circuit |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US9985543B1 (en) | Switching power supply | |
| CN100452603C (en) | Inspecting circuit and method for switching power-supply outputting voltage | |
| CN100571000C (en) | The semiconductor device that comprises dc-dc converter control circuit | |
| CN203536942U (en) | A novel ring choke converter output overvoltage protection circuit | |
| US20150188361A1 (en) | Bypass type 220v grid voltage sag prevention device and control method therefor | |
| CN101188356A (en) | Protection circuit and its method | |
| KR101872627B1 (en) | Flyback quick start driving circuit and driving method | |
| US8912731B2 (en) | LED backlight driving circuit and backlight module | |
| CN112512163A (en) | Output overvoltage protection control circuit and drive circuit | |
| CN106558980B (en) | A kind of enabled control circuit | |
| CN109194109A (en) | A kind of compensation circuit | |
| CN208890638U (en) | A kind of compensation circuit | |
| CN103354690A (en) | Auxiliary-winding-free primary side controlled LED (light-emitting diode) driving circuit and PFC (power factor correction) constant-current control circuit thereof | |
| CN102017382A (en) | Method of forming a detection circuit and structure therefor | |
| CN102339082B (en) | Power level control circuit | |
| CN112350279A (en) | Power supply protection circuit and electronic device | |
| CN111416422A (en) | Power supply switching circuit and power supply system | |
| CN111565290A (en) | LED power supply overvoltage protection circuit, LED drive power supply circuit and television | |
| US9832836B2 (en) | Drive circuit for illuminating device and illuminating device having the drive circuit | |
| CN208571920U (en) | A kind of compensation circuit | |
| CN109066598A (en) | A kind of low level triggering latching circuit | |
| CN205793505U (en) | A kind of LED backlight circuit and liquid crystal TV set | |
| CN114464500A (en) | Control method of low-power consumption monostable or bistable relay | |
| CN210225845U (en) | Load overvoltage protection circuit and protection chip | |
| CN109245513B (en) | Starting circuit |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |