CN206481218U - A kind of power circuit - Google Patents
A kind of power circuit Download PDFInfo
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- CN206481218U CN206481218U CN201720171355.6U CN201720171355U CN206481218U CN 206481218 U CN206481218 U CN 206481218U CN 201720171355 U CN201720171355 U CN 201720171355U CN 206481218 U CN206481218 U CN 206481218U
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Abstract
The utility model discloses a kind of power circuit, including：Power stage circuit and control circuit, described control circuit is connected with the control end of the power stage circuit, the Power convert for controlling circuit control power stage circuit, the output of the power stage as the power circuit output；When the output current of the power circuit is less than cut-off current Iref, then its output voltage keeps pressure constant state, and output voltage values are V1；When the output current Iout of the power circuit exceedes cut-off current Iref and is less than maximum permissible value Imax, then its output voltage declines with the increase of the output current Iout, and output voltage values are V2.The utility model can continue output current in the case of electricity shortage, and power output can be kept to be basically unchanged again to avoid heating.
Description
Technical field
The utility model is related to electric and electronic technical field, more specifically to a kind of power circuit.
Background technology
In the prior art, generally power circuit is powered or charged using adapter.As shown in figure 1, being prior art
Power circuit, including power stage circuit and current limiting switch, the current limiting switch is when adapter charges to the power circuit
It is used as input current limliting.After adapter or charger disconnect, in the case that power circuit is powered to terminal, when power circuit connection
Terminal device sourcing current it is excessive or short-circuit when, power circuit power supply capacity is not enough, it may appear that heating or work a period of time
After the problems such as turn off.As shown in figure 1, illustrating the basic circuit structure of the power circuit of prior art.
When electric current needed for power circuit disclosure satisfy that terminal device, power circuit normal work is pressure constant state, VOUT
=VREF* (R1+R2)/R2；When the electric current needed for the power supply capacity of power circuit is not enough to maintenance terminal device, current-clamp
Circuit works, and VCOMP is clamped at maximum, and VFB is gradually reduced, and VOUT declines, and power circuit is operated in maximum current state,
The equipment may always work at this state, occur power output it is excessive cause power circuit generate heat or output voltage VO UT
Less than preset value, turned off after work a period of time, that is, stop powering to terminal.
More than in the prior art, due to reaching that cut-off current, or output voltage are less than when the output current of power circuit
During preset value, it is stopped over time.Accordingly, there exist output current ability it is relatively low, heating (or even before current limliting just send out
It is hot serious) etc. technical problem.
Utility model content
In view of this, the utility model proposes a kind of power circuit, according to after output current exceedes cut-off current, remain to
Output current, lifts output current ability, and keeps power output to be basically unchanged, and can avoid heating problem.
According to a kind of power circuit of the present utility model, including：Power stage circuit and control circuit, described control circuit
It is connected with the control end of the power stage circuit, the control circuit controls the Power convert of power stage circuit, the power stage
Output as the power circuit output；
When the output current of the power circuit is less than cut-off current Iref, then its output voltage keeps pressure constant state, output
Magnitude of voltage is V1；When the output current Iout of the power circuit exceedes cut-off current Iref and less than maximum permissible value Imax, then
Its output voltage declines with the increase of the output current Iout, and output voltage values are V2.
Further, described output voltage drops to linear decline with output current, and (V1-V2)/(Iout-Iref) is protected
Hold constant.So that power output keeps being basically unchanged.
Further, when the output current Iout of the power circuit reaches maximum permissible value, then make it that output voltage is low
In Low threshold, start output current overcurrent protection.
Further, described control circuit includes output voltage sampling circuit, output current detection circuit, regulation circuit
With drive control circuit, the output voltage sampling circuit receives the output voltage of the power circuit, and defeated in its output end
Go out voltage sampling signal, described output current detection circuit detects the output current of the power circuit, and detection is obtained
Sign output current signal with characterize cut-off current signal make difference processing, obtain characterize difference current signal, defeated
When going out electric current more than cut-off current, the signal of the sign difference current is added into the output end in output voltage sampling circuit, institute
The regulation circuit stated is connected with the output end of the output voltage sampling circuit, and the regulation circuit also receives sign output current
The voltage reference signal VREF that the signal and sign magnitude of voltage of instantaneous value are V1, the output end of the regulation circuit and the driving
Circuit connection is controlled, described drive control circuit is connected with the control end of the power stage circuit.
Further, described regulation circuit includes the first amplifier and current regulating circuit, and the of described the first amplifier
One input receives the voltage reference signal, and its second input is connected with the output end of the output current detection circuit,
The first input end of described current regulating circuit is connected with the output end of first amplifier, and the second of current regulating circuit is defeated
Enter the signal that end receives the output current instantaneous value for characterizing power circuit, output end and the drive control circuit of current regulating circuit
Connection.
Further, described output voltage sampling circuit includes the first resistor and second resistance being serially connected, first
Resistance connects hot end, and second resistance connects cold end, and the common port of the two exceedes cut-off current as output end in output current
Output voltage rate of change after Iref.
Further, described control circuit includes output voltage sampling circuit, output current detection circuit, regulation circuit
With drive control circuit, the output voltage sampling circuit receives the output voltage of the power circuit, and defeated in its output end
Go out voltage sampling signal, described output current detection circuit detects the output current of the power circuit, and detection is obtained
Sign output current signal with characterize cut-off current signal make difference processing, obtain characterize difference current signal, it is described
Regulation circuit be connected with the output end of the output voltage sampling circuit, it is described regulation circuit also receive sign output current wink
The voltage reference signal VREF that the signal and sign magnitude of voltage of duration are V1, and receive described when output current exceedes cut-off current
The signal of difference current is characterized, the output end of the regulation circuit is connected with the drive control circuit, described drive control
Circuit is connected with the control end of the power stage circuit.
Further, described regulation circuit includes the first amplifier, current regulating circuit and clamp circuit, described first
The first input end of amplifier receives the voltage reference signal, the output of its second input and the output current detection circuit
End connection, the first input end of described current regulating circuit is connected with the output end of first amplifier, current regulating circuit
The second input receive the signal of the output current instantaneous value for characterizing power circuit, the output end of current regulating circuit and driving
Control circuit connection；The output end of the clamp circuit is connected to the common port of the first amplifier and current regulating circuit, clamper electricity
The input on road receives the signal for characterizing difference current.
In summary, according to the utility model power circuit, in the case where power circuit is to terminal normal power supply, output
Voltage is in pressure constant state, and when electric current needed for the power supply capacity of power circuit is not enough to maintain terminal, then output current can surpass
Over current value, in the case of less than maximum permissible value, then its output voltage declines with the increase of the output current, with
Keep the substantially constant of power output.The utility model can continue output current, and can keep in the case of electricity shortage
Power output is basically unchanged to avoid heating.
Brief description of the drawings
Fig. 1 show the structural representation of power circuit in the prior art；
Fig. 2 show the output waveform diagram of the utility model power circuit；
Fig. 3 show the structural representation of the utility model power circuit embodiment one；
Fig. 4 show the structural representation of the utility model power circuit embodiment two.
Embodiment
Preferred embodiment of the present utility model is described in detail below in conjunction with accompanying drawing, but the utility model is not merely
It is limited to these embodiments.The utility model covers any replacement made in spirit and scope of the present utility model, modification, equivalent
Method and scheme.
Thoroughly understand in order that the public has to the utility model, in following the utility model preferred embodiment specifically
Understand concrete details, and description without these details can also understand that this practicality is new completely for a person skilled in the art
Type.
With reference to shown in 2, the output waveform of power circuit is illustrated, output waveform change is based on the power supply electricity shown in Fig. 4
Road, including：Power stage circuit and control circuit, described control circuit is connected with the control end of the power stage circuit, described
Control circuit to control the Power convert of power stage circuit, the output of the power stage as the power circuit output.
When the output current of the power circuit is less than cut-off current Iref, then its output voltage keeps pressure constant state, i.e., just
Situation about often working, output voltage values are V1, and as reference voltage, are characterized in fig. 2 by VREF；When power supply electricity
The output current Iout on road exceedes cut-off current Iref and less than maximum permissible value Imax, then its output voltage is with the output electricity
Flow Iout increase and decline, output voltage values are V2.Described output voltage rises to linear decline with output current, (V1-
V2)/(Iout-Iref)=C, C are constant.So that power output keeps being basically unchanged.When the output of the power circuit
Electric current Iout reaches maximum permissible value Imax, then causes output voltage to be less than Low threshold VL, starts output current overcurrent protection.
The utility model is defined to the curve of output that power circuit is powered to terminal, exceedes current value in electric current
Afterwards, output can't be directly turned off, but the mode for keeping power output to be basically unchanged by the way of reduction output voltage
Continue to output electric current.Fig. 3 only has given the example that output voltage linearly declines, but non-linear decline or other regularly under
Drop can also be implemented.
With reference to shown in 3, the circuit structure of power circuit embodiment one of the present utility model is illustrated.The power circuit bag
Include：Power stage circuit and control circuit, described control circuit are connected with the control end of the power stage circuit, the control electricity
Road controls the Power convert of power stage circuit, the output of the power stage as the power circuit output.In adapter pair
The input that power circuit is powered is provided with current limiting switch Q1, for the input current limliting of adapter, because the utility model is main
Consider the situation that power circuit is powered to terminal, therefore current limiting switch Q1 control does not elaborate, but people in the art
Member can know current limiting switch Q1 operation principle and effect.
Described power stage circuit includes switching tube Q2, switching tube Q3, inductance L1 and battery, described battery and anode with
Inductance L1 one end connection, the inductance L1 other end is connected to switching tube Q2 and switching tube Q3 common port.The of switching tube Q2
One end is connected with switching tube Q3 first end, and the control end of the two is connected with drive control circuit.Switching tube Q2 the second end
For hot end, switching tube Q3 the second end is cold end, and described hot end and cold end are as output end to end
End power supply.
Described control circuit includes output voltage sampling circuit, output current detection circuit, regulation circuit and driving control
Circuit processed, the output voltage sampling circuit receives the output voltage of the power circuit, and is adopted in its output end output voltage
Sample signal, described output current detection circuit detects the output current of the power circuit, and will detect that obtained sign is defeated
The signal for going out electric current makees difference processing with characterizing the signal of cut-off current, obtains characterizing the signal of difference current, super in output current
When crossing cut-off current, the signal of the sign difference current is added into the output end in output voltage sampling circuit, described regulation
Circuit is connected with the output end of the output voltage sampling circuit, and the regulation circuit, which is also received, characterizes output current instantaneous value
The voltage reference signal VREF that signal and sign magnitude of voltage are V1, the output end of the regulation circuit and the drive control circuit
Connection, described drive control circuit is connected with the control end of the power stage circuit.
Described output voltage sampling circuit is composed in series by resistance R1 and R2, by sampled output Vout voltage,
Output end (i.e. resistance R1 and R2 common port) output voltage sampled signal VFB of output voltage sampling circuit.Output current is examined
Slowdown monitoring circuit includes current detection module and difference processing module, and described voltage detection module detection output current is characterized
The signal IAVG of output current average value, relation proportional to output current average value, the cut-off current of output current is Iref, is used
It is proportional to the IREF of relation to characterize, difference current IAVG-IREF is obtained after the processing of difference processing module, will be described
Difference current adds the output end (i.e. resistance R1 and R2 common port) in output voltage sampling circuit.
Described regulation circuit includes amplifier 1 (being used as the first amplifier) and current regulating circuit, the first of described amplifier 1
Input receives the voltage reference signal VREF, and the output end of its second input and the output current detection circuit connects
Connect, the first input end of described current regulating circuit is connected with the output end of the amplifier 1, and the second of current regulating circuit is defeated
Enter the output current instantaneous value that end receives power circuit, the output end of current regulating circuit is connected with drive control circuit.Amplifier 1
The effect of Voltage loop is served, current regulating circuit serves the effect of electric current loop, and current regulating circuit is by controlling Q2 and Q3
Conducting and cut-off adjust inductive current, so as to adjust output current.The utility model feedovers difference current to VFB, then
It is adjusted using Voltage loop and electric current loop.
Wherein, IAVG is used to characterizing the Q2 average current detected, that is, output current average value.When output electricity
When stream is more than the IREF for characterizing cut-off current, both difference between currents are sent on FB divider resistances R2, then had
By can be calculated IAVG-IREF=(V1-Vout)/R1.It is consistent with the curve of output for needing to set.If electric
Resistance partial pressure be arranged on piece it is outer or in piece it is adjustable, moreover it is possible to realize and the adjustable function of curve of output be set, that is, different resistances are set
First resistor carry out the output voltage of regulation power supply circuit.
With reference to shown in 4, the circuit structure of power circuit embodiment two of the present utility model is illustrated.With the area of embodiment one
The difference of regulation circuit is not essentially consisted in.Described regulation circuit includes the first amplifier (amplifier 1), current regulating circuit and clamper
Circuit, the first input end of described the first amplifier receives the voltage reference signal VREF, its second input with it is described defeated
Go out the output end connection of voltage sampling circuit, the first input end of described current regulating circuit and the output of first amplifier
End connection, the second input of current regulating circuit receives the signal for the output current instantaneous value for characterizing power circuit, and electric current is adjusted
The output end on economize on electricity road is connected with drive control circuit；The output end of the clamp circuit is connected to the first amplifier and adjusted with electric current
The common port of circuit, the input of clamp circuit receives the signal IAVG-IREF for characterizing difference current.The present embodiment also can
Realize after output current exceedes cut-off current Iref, output voltage is reduced with the increase of output current, but its output waveform
Different with Fig. 2, according to different embodiments, also there are other and deform in output waveform.With embodiment in the present embodiment
One identical part refers to the description in embodiment one.
Embodiment two is just carried out after output current exceedes cut-off current Iref by clamp circuit to the output end of amplifier 1
Clamper, to limit and adjust the rising of electric current, and controls clamp circuit according to the signal IAVG-IREF of difference current is characterized
Clamp voltage.
It should be noted that the output current Iout described by the utility model is average in the case of without specified otherwise
Electric current；Iref is actual cut-off current, and IREF is to carry out the limit after ratio adjustment in embodiment according to actual cut-off current
Flow valuve.V1 is the reference voltage VREF relations proportional to V1 in the constant pressure value under normal operation, figure.Due to participating in computing
Parameter size and the actual size of parameter there are in proportionate relationship, Fig. 3 involved partial parameters, the parameter characterized with it
Proportional relation.
In addition, although embodiment is separately illustrated and illustrated above, but it is related to the common technology in part, in this area
Those of ordinary skill apparently, can be replaced and integrate between the embodiments, be related to one of embodiment and record is not known
Content, then refer to another embodiment on the books.
Above to having carried out detailed description according to preferred embodiment of the present utility model, but circuit on the patent and have
Beneficial effect should not be considered as being limited only to described above, and disclosed embodiment and accompanying drawing can be better understood from this practicality
New, therefore, embodiment and Figure of description content disclosed above is that, in order to be better understood from the utility model, this practicality is new
Type protection is not limited to embodiment scope of disclosure, those of ordinary skill in the art to the replacement of the utility model embodiment, repair
Change within protection domain of the present utility model.
Claims (8)
1. a kind of power circuit, including：Power stage circuit and control circuit, described control circuit and the power stage circuit
Control end is connected, and the control circuit controls the Power convert of power stage circuit, and the output of the power stage is used as the power supply
The output of circuit；
When the output current of the power circuit is less than cut-off current Iref, then its output voltage keeps pressure constant state, output voltage
It is worth for V1；When the output current Iout of the power circuit exceedes cut-off current Iref and is less than maximum permissible value Imax, then its is defeated
Go out voltage with the increase of the output current Iout to decline, output voltage values are V2.
2. power circuit according to claim 1, it is characterised in that described output voltage drops to line with output current
Property decline, (V1-V2)/(Iout-Iref) keep it is constant.
3. power circuit according to claim 2, it is characterised in that when the output current Iout of the power circuit reaches
Maximum permissible value Imax, then cause output voltage to be less than Low threshold, starts output current overcurrent protection.
4. power circuit according to claim 3, it is characterised in that described control circuit includes output voltage sampling electricity
Road, output current detection circuit, regulation circuit and drive control circuit, the output voltage sampling circuit receive the power supply electricity
The output voltage on road, and in its output end output voltage sampled signal, described output current detection circuit detects the power supply
The output current of circuit, and will detect that the signal of the signal and sign cut-off current of obtained sign output current makees difference processing,
Obtain characterize difference current signal, output current exceed cut-off current when, by it is described sign difference current signal add in
The output end of output voltage sampling circuit, described regulation circuit is connected with the output end of the output voltage sampling circuit, institute
Regulation circuit is stated also to receive the signal for characterizing output current instantaneous value and characterize the voltage reference signal VREF that magnitude of voltage is V1, institute
The output end for stating regulation circuit is connected with the drive control circuit, described drive control circuit and the power stage circuit
Control end is connected.
5. power circuit according to claim 4, it is characterised in that described regulation circuit includes the first amplifier and electric current
Adjust circuit, the first input end of described the first amplifier receives the voltage reference signal, its second input with it is described defeated
Go out the output end connection of current detection circuit, the first input end of described current regulating circuit and the output of first amplifier
End connection, the second input of current regulating circuit receives the signal for the output current instantaneous value for characterizing power circuit, and electric current is adjusted
The output end on economize on electricity road is connected with drive control circuit.
6. power circuit according to claim 4, it is characterised in that described output voltage sampling circuit includes mutual string
The first resistor and second resistance of connection, first resistor connect hot end, and second resistance connects cold end, the common port conduct of the two
Output end, sets the first resistor of different resistances to adjust the output voltage change after output current exceedes cut-off current Iref
Rate.
7. power circuit according to claim 2, it is characterised in that described control circuit includes output voltage sampling electricity
Road, output current detection circuit, regulation circuit and drive control circuit, the output voltage sampling circuit receive the power supply electricity
The output voltage on road, and in its output end output voltage sampled signal, described output current detection circuit detects the power supply
The output current of circuit, and will detect that the signal of the signal and sign cut-off current of obtained sign output current makees difference processing,
Obtain characterizing the signal of difference current, described regulation circuit is connected with the output end of the output voltage sampling circuit, described
Regulation circuit also receives the signal for characterizing output current instantaneous value and characterizes the voltage reference signal VREF that magnitude of voltage is V1, and
Output current receives the signal of the sign difference current, the output end of the regulation circuit and the driving when exceeding cut-off current
Circuit connection is controlled, described drive control circuit is connected with the control end of the power stage circuit.
8. power circuit according to claim 7, it is characterised in that described regulation circuit includes the first amplifier, electric current
Circuit and clamp circuit are adjusted, the first input end of the first described amplifier receives the voltage reference signal, its second input
End is connected with the output end of the output current detection circuit, the first input end and described first of described current regulating circuit
The output end connection of amplifier, the second input of current regulating circuit receives the letter for the output current instantaneous value for characterizing power circuit
Number, the output end of current regulating circuit is connected with drive control circuit；The output end of the clamp circuit is connected to the first amplifier
With the common port of current regulating circuit, the input of clamp circuit receives the signal for characterizing difference current.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201720171355.6U CN206481218U (en) | 2017-02-24 | 2017-02-24 | A kind of power circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201720171355.6U CN206481218U (en) | 2017-02-24 | 2017-02-24 | A kind of power circuit |
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| Publication Number | Publication Date |
|---|---|
| CN206481218U true CN206481218U (en) | 2017-09-08 |
Family
ID=59746546
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201720171355.6U Active CN206481218U (en) | 2017-02-24 | 2017-02-24 | A kind of power circuit |
Country Status (1)
| Country | Link |
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| CN (1) | CN206481218U (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106849660A (en) * | 2017-02-24 | 2017-06-13 | 杰华特微电子（杭州）有限公司 | Power circuit and its control method |
| CN108023468A (en) * | 2017-12-28 | 2018-05-11 | 杰华特微电子（杭州）有限公司 | Switching power source control circuit and Switching Power Supply |
| CN113760032A (en) * | 2021-09-18 | 2021-12-07 | 普冉半导体(上海)股份有限公司 | Low-power consumption clamping circuit |
-
2017
- 2017-02-24 CN CN201720171355.6U patent/CN206481218U/en active Active
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106849660A (en) * | 2017-02-24 | 2017-06-13 | 杰华特微电子（杭州）有限公司 | Power circuit and its control method |
| CN106849660B (en) * | 2017-02-24 | 2023-06-23 | 杰华特微电子股份有限公司 | Power supply circuit and control method thereof |
| CN108023468A (en) * | 2017-12-28 | 2018-05-11 | 杰华特微电子（杭州）有限公司 | Switching power source control circuit and Switching Power Supply |
| CN113760032A (en) * | 2021-09-18 | 2021-12-07 | 普冉半导体(上海)股份有限公司 | Low-power consumption clamping circuit |
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Address after: Room 901-23, 9 / F, west 4 building, Xigang development center, 298 Zhenhua Road, Sandun Town, Xihu District, Hangzhou City, Zhejiang Province, 310030 Patentee after: Jiehuate Microelectronics Co.,Ltd. Address before: Room 424, building 1, 1500 Wenyi West Road, Cangqian street, Yuhang District, Hangzhou City, Zhejiang Province Patentee before: JOULWATT TECHNOLOGY (HANGZHOU) Co.,Ltd. |
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