CN107943190A - A kind of low pressure difference regulated power supply with overcurrent protection function - Google Patents
A kind of low pressure difference regulated power supply with overcurrent protection function Download PDFInfo
- Publication number
- CN107943190A CN107943190A CN201810011948.5A CN201810011948A CN107943190A CN 107943190 A CN107943190 A CN 107943190A CN 201810011948 A CN201810011948 A CN 201810011948A CN 107943190 A CN107943190 A CN 107943190A
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- switching tube
- drain electrode
- sampling
- source electrode
- grid
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- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05F—SYSTEMS FOR REGULATING ELECTRIC OR MAGNETIC VARIABLES
- G05F1/00—Automatic systems in which deviations of an electric quantity from one or more predetermined values are detected at the output of the system and fed back to a device within the system to restore the detected quantity to its predetermined value or values, i.e. retroactive systems
- G05F1/10—Regulating voltage or current
- G05F1/46—Regulating voltage or current wherein the variable actually regulated by the final control device is dc
- G05F1/56—Regulating voltage or current wherein the variable actually regulated by the final control device is dc using semiconductor devices in series with the load as final control devices
- G05F1/561—Voltage to current converters
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- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- General Physics & Mathematics (AREA)
- Radar, Positioning & Navigation (AREA)
- Automation & Control Theory (AREA)
- Dc-Dc Converters (AREA)
Abstract
The invention discloses a kind of low pressure difference regulated power supply with overcurrent protection function, including sampling switching tube (S9) is used with switching tube (S2) and adjustment, the sampling meets input power Vin with the source electrode and the adjustment of switching tube (S2) with switching tube (S9), in the sampling feedback circuit is added with the drain electrode of switching tube (S2), the feedback circuit includes error amplifier (EA), the drain electrode of error amplifier (EA) the in-phase input end connection sampling switching tube (S2), its inverting input connects the output terminal of regulated power supply, error signal is amplified the pressure drop of control adjustment switching tube (S9) later by error amplifier, and then regulated output voltage.It ensure that the sampling accuracy of output current, greatly reduce the shut-off power consumption of system.
Description
Technical field
The present invention relates to regulated power supply field, in particular to a kind of low voltage difference voltage stabilizing with overcurrent protection function
Power supply.
Background technology
In the prior art, with the rapid development of electronic technology, linear stabilized power supply wide hair in various mobile electricity
In subsystem, the defencive functions such as existing linear stabilized power supply chip is generally closed with heat and output current limits, and it is linear
Current protection technology in regulated power supply is always to influence the key of linear stabilized power supply system stable operation.The mesh of overcurrent protection
Be in order to which output current is limited in a fixed scope, when output short-circuit or electric current exceed danger threshold to whole
Regulated power supply system or load are protected, and there are reliability is high, overcurrent turn-off function power consumption more for traditional current foldback circuit
The problems such as high.Adjustment is crossed in existing current foldback circuit with switching tube convection current using sampling to be carried out with the input current of switching tube
The change of output current has been reacted in sampling, sampling with the leakage current of switching tube.The grid of sampling switching tube and adjustment switching tube
Source voltage is equal, but cannot simultaneously ensure that both drain voltages are also equal, so that sampling switching tube can be caused to output electricity
Stream sampling is inaccurate, influences sampling precision, while the reliability of current foldback circuit reduces, and the power consumption of system is also bigger.
For above-mentioned technical problem, not yet propose to efficiently solve scheme at present.
The content of the invention
The present invention proposes a kind of low pressure difference regulated power supply with overcurrent protection, can not only solve overcurrent in the prior art
Protect that circuit sampling is inaccurate, reliability is low, the big technical problem of the power consumption of system, and simple in structure, high conversion efficiency.
One side according to embodiments of the present invention, the present invention is realized by following technical scheme：One kind has overcurrent
The low pressure difference regulated power supply of defencive function, including sampling use switching tube (S9) with switching tube (S2) and adjustment, described to sample with opening
The source electrode and the adjustment for closing pipe (S2) with switching tube (S9) meet input power Vin, in the sampling with switching tube (S2)
Drain electrode end add a feedback circuit, the feedback circuit includes error amplifier (EA), the error amplifier (EA)
The in-phase input end connection sampling drain electrode of switching tube (S2), output of its inverting input as the regulated power supply
End, error amplifier (EA) output terminal connect the grid of the 3rd switching tube (S3), the source electrode of the 3rd switching tube (S3)
It is grounded through first resistor (R0), its connection to drain with the sampling drain electrode of switching tube (S2), error signal passes through error
Amplifier is amplified the pressure drop of control adjustment switching tube (S9) later, and then regulated output voltage.
Further, the source electrode of the 5th switching tube (S5) of input power Vin connections, the 5th switching tube (S5)
The source electrode of drain electrode the 6th switching tube (S6) of connection, the drain electrode of the 6th switching tube (S6) connect the drain electrode of the 7th switching tube (S7), institute
The source electrode for stating the 7th switching tube (S7) is connected to reference ground by 3rd resistor (R3)；The source electrode of 4th switching tube (S4) and described
The source electrode connection of 5th switching tube (S5), the drain electrode of the 4th switching tube (S4) and the grid of the 5th switching tube (S5) with
And adjustment is connected with the grid of switching tube (S9), one end of the 4th resistance (R4) connects the source electrode of the 4th switching tube (S4), described
4th resistance (R4) other end connects the drain electrode of the grid and the 8th switching tube (S8) of the 4th switching tube (S4), the 8th switching tube
(S8) grid is connected with the grid of the 7th switching tube (S7) and drain electrode, the source electrode and the 6th switching tube of the 8th switching tube (S8)
(S6) grid and adjustment is connected with the drain electrode of switching tube (S9)；First switch pipe (S1), sampling switching tube (S2), adjustment
It is connected with the source electrode of switching tube (S9) with the source electrode of the 4th switching tube (S4), the 5th switching tube (S5), first switch pipe (S1)
Drain and be connected with the grid and sampling adjusted with switching tube (S9) with the grid of switching tube (S2), the source of the 3rd switching tube (S3)
Pole is connected with the one end of first resistor (R0), the other end connection reference ground of first resistor (R0), one end of first resistor (R0)
The inverting input of comparator, comparator noninverting input reference voltage Vref are also connected with, comparator output terminal connection first is opened
Close the grid of pipe (S1).
Advantageous effects acquired by the present invention are：
(1) it is simple in structure；The technical solution adopted in the present invention is without complicated control circuit or control chip etc., topology
Structure only increases feedback circuit in the drain electrode of sampling diode, you can ensures the accuracy of sampling；
(2) low in energy consumption, high conversion efficiency is turned off；Error signal is amplified control adjustment later by error amplifier and uses
The pressure drop of switching tube S9, and then regulated output voltage, also ensure that the sampling accuracy of output current.Meanwhile regulated power supply is defeated
During outlet overcurrent, output current can be made to be reduced with the reduction of output voltage, greatly reduce the shut-off power consumption of system, and
And sample resistance R0 is no and adjustment is connected with switching tube, because not damaging pressure, further increases transfer efficiency.
Brief description of the drawings
From following description with reference to the accompanying drawings it will be further appreciated that the present invention.Component in figure is not drawn necessarily to scale,
But focus on and show in the principle of embodiment.In figure, in different views, identical reference numeral specifies correspondence
Part.
Fig. 1 is the low voltage difference voltage-stabilized power supply circuit structure chart with overcurrent protection function of the present invention.
Embodiment
In order to enable the objects, technical solutions and advantages of the present invention are more clearly understood, below in conjunction with attached drawing and its implementation
Example, the present invention will be described in further detail；It should be appreciated that specific embodiment described herein is only used for explaining this hair
It is bright, it is not intended to limit the present invention.To those skilled in the art, after access is described in detail below, the present embodiment
Other systems, method and/or feature will become obvious.It is intended to all such additional systems, method, feature and advantage
It is included in this specification, is included within the scope of the invention, and is protected by the appended claims.In detailed below
Describe the other feature of the disclosed embodiments, and these characteristic roots according to it is described in detail below will be aobvious and easy
See.
It is as follows referring to attached drawing 1, the regulated power supply structure：The source electrode of input power Vin connecting valve pipes S5, switching tube S5's
The source electrode of drain electrode connecting valve pipe S6, the drain electrode of the drain electrode connecting valve pipe S7 of switching tube S6, the source electrode of switching tube S7 pass through electricity
Resistance R3 is connected to reference ground；The source electrode of switching tube S4 is connected with the source electrode of S5, the drain electrode of switching tube S4 and the grid and tune of S5
The whole grid with switching tube S9 is connected, the source electrode of one end connecting valve pipe S4 of resistance R4, R4 other end connecting valve pipes S4's
The drain electrode of grid and switching tube S8, the grid of switching tube S8 are connected with the drain electrode of the grid of S7 and S7, the source electrode of S8 and S6's
The drain electrode of grid and S9 are connected；Switching tube S1, sampling switching tube S2, the adjustment source electrode of switching tube S9 and switching tube S4,
The source electrode of S5 is connected, and the drain electrode of S1 is connected with the grid of S9 and the grid of S2, and the drain electrode of S2 is connected with the drain electrode of switching tube S3,
The source electrode of S3 is connected with one end of resistance R0, and the other end connection reference ground of resistance R0, one end of R0 is also connected with the anti-of comparator
Phase input terminal, comparator noninverting input connect reference voltage Vref, and comparator output terminal connects the grid of S1.
The drain electrode of in-phase input end connecting valve the pipe S2 and S3 of error amplifier, its inverting input connection resistance R1
One end and S9 drain electrode and S6 grid, output of the tie point as low pressure difference regulated power supply, the other end of resistance R1
Connect one end of resistance R2, the other end connection reference ground of resistance R2.The drain electrode end of switching tube S2 adds a feedback circuit,
Not only can be with regulated output voltage, it can also be ensured that the drain voltage of both sampling switching tube and adjustment switching tube is equal,
Ensure the accuracy that sampling switching tube samples output current.
The feedback circuit includes error amplifier EA, its in-phase input end connects the drain electrode of S2, and inverting input was used as
The output terminal of stream protection circuit, error amplifier output connect the grid of S3, i.e. error signal is carried out by error amplifier
Amplification controlled the pressure drop of adjustment switching tube S9, and then regulated output voltage later.
Sampling voltage is added in the in-phase input end of error amplifier EA, compared with the reference voltage for being added in inverting input
Compared with the reference voltage is the output voltage of low pressure difference regulated power supply, and difference between the two is after EA amplifies, control series connection
The pressure drop of pipe is adjusted, and then stablizes the output voltage of regulated power supply, if regulated power supply overload has exceeded limitation electric current, power tube
It will be burnt under lasting high current.The ability to bear of power tube determines working condition of the power supply under overcurrent effect, the overcurrent
Protect circuit to mask the over-current signal not interrupted, exceed preset range for overcurrent amplitude and continuous action time
Over-current signal, current foldback circuit just using interrupt normal work pattern, in practical applications, the heat that power tube is born
Power consumption and breakdown current are limited, its maximum breakdown current determines the maximum amplitude of overcurrent.Needed for specific application,
Can be by setting rational shielding time and maximum overcurrent amplitude so that linear voltage regulator is efficiently and reliably run.
The present invention improves sampling essence by way of setting a feedback circuit with the drain electrode end of switching tube S2 in sampling
Degree, the feedback circuit include error amplifier EA, its in-phase input end connects the drain electrode of S2, and inverting input connects the defeated of circuit
Outlet, error amplifier output connect the grid of S3, i.e. error signal is amplified control later by error amplifier and adjusts
The whole pressure drop with switching tube S9, and then regulated output voltage, also ensure that the sampling accuracy of output current.Meanwhile voltage stabilizing electricity
During source output terminal overcurrent, output current can be made to be pressed with the reduction of output voltage without damaging, further increase conversion effect
Rate.
Although by reference to various embodiments, the invention has been described above, but it is to be understood that is not departing from the present invention's
In the case of scope, many changes and modifications can be carried out.Therefore, its be intended to foregoing detailed description be considered as it is illustrative and
It is nonrestrictive, and it is to be understood that following claims (including all equivalents) is intended to limit the spirit and model of the present invention
Enclose.The above embodiment is interpreted as being merely to illustrate the present invention rather than limits the scope of the invention.Reading
After the content of the record of the present invention, technical staff can make various changes or modifications the present invention, these equivalence changes and
Modification equally falls into the scope of the claims in the present invention.
Claims (2)
1. a kind of low pressure difference regulated power supply with overcurrent protection function, it includes sampling switching tube (S2) and adjustment switch
Manage (S9), the sampling meets input power Vin with the source electrode and the adjustment of switching tube (S2) with switching tube (S9), it is special
Sign is：A feedback circuit is added with the drain electrode end of switching tube (S2) in the sampling, the feedback circuit includes error
Amplifier (EA), error amplifier (EA) the in-phase input end connection sampling drain electrode of switching tube (S2), its is anti-phase
Output terminal of the input terminal as the regulated power supply, error amplifier (EA) output terminal connect the grid of the 3rd switching tube (S3)
Pole, the source electrode of the 3rd switching tube (S3) are grounded through first resistor (R0), it drains and the sampling switching tube (S2)
The connection of drain electrode, error signal are amplified the pressure drop of control adjustment switching tube (S9) later by error amplifier, and then
Regulated output voltage.
2. low pressure difference regulated power supply according to claim 1, it is characterised in that：The input power Vin connections the 5th are opened
The source electrode of pipe (S5) is closed, the drain electrode of the 5th switching tube (S5) connects the source electrode of the 6th switching tube (S6), the 6th switching tube
(S6) drain electrode connects the drain electrode of the 7th switching tube (S7), and the source electrode of the 7th switching tube (S7) is connected by 3rd resistor (R3)
It is connected to reference ground；The source electrode of 4th switching tube (S4) is connected with the source electrode of the 5th switching tube (S5), the 4th switching tube
(S4) drain electrode is connected with the grid of the 5th switching tube (S5) and adjustment with the grid of switching tube (S9), the 4th resistance
(R4) one end connects the source electrode of the 4th switching tube (S4), and the 4th resistance (R4) other end connects the 4th switching tube (S4)
The drain electrode of grid and the 8th switching tube (S8), the grid of the 8th switching tube (S8) and the grid of the 7th switching tube (S7) and drain electrode phase
Even, the source electrode of the 8th switching tube (S8) is connected with the grid of the 6th switching tube (S6) and adjustment with the drain electrode of switching tube (S9)；
First switch pipe (S1), sampling switching tube (S2), the source electrode and the 4th switching tube of adjustment switching tube (S9)
(S4), the source electrode of the 5th switching tube (S5) is connected, drain electrode and the adjustment switching tube of first switch pipe (S1)
(S9) grid and sampling is connected with the grid of switching tube (S2), the source electrode and first resistor of the 3rd switching tube (S3)
(R0) one end connection, the other end connection reference ground of first resistor (R0), one end of first resistor (R0) is also connected with comparator
Inverting input, comparator noninverting input reference voltage Vref, comparator output terminal connection first switch pipe (S1) grid
Pole.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810011948.5A CN107943190A (en) | 2018-01-05 | 2018-01-05 | A kind of low pressure difference regulated power supply with overcurrent protection function |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810011948.5A CN107943190A (en) | 2018-01-05 | 2018-01-05 | A kind of low pressure difference regulated power supply with overcurrent protection function |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN107943190A true CN107943190A (en) | 2018-04-20 |
Family
ID=61938430
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201810011948.5A Withdrawn CN107943190A (en) | 2018-01-05 | 2018-01-05 | A kind of low pressure difference regulated power supply with overcurrent protection function |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN107943190A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110069092A (en) * | 2019-04-18 | 2019-07-30 | 上海华力微电子有限公司 | The current foldback circuit of LDO circuit device and LDO circuit |
| CN110554724A (en) * | 2018-06-02 | 2019-12-10 | 丹阳恒芯电子有限公司 | overcurrent protection circuit |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3610556B1 (en) * | 2003-10-21 | 2005-01-12 | ローム株式会社 | Constant voltage power supply |
| CN102915069A (en) * | 2012-09-19 | 2013-02-06 | 中国兵器工业集团第二一四研究所苏州研发中心 | Overcurrent protection circuit of low dropout linear voltage stabilizer |
| CN204009654U (en) * | 2014-06-25 | 2014-12-10 | 万源市海铝科技有限公司 | For the current foldback circuit of linear voltage regulator |
| CN205212692U (en) * | 2015-10-22 | 2016-05-04 | 北京经纬恒润科技有限公司 | Low dropout regulator's current foldback circuit and low voltage difference linear constant voltage power supply |
-
2018
- 2018-01-05 CN CN201810011948.5A patent/CN107943190A/en not_active Withdrawn
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3610556B1 (en) * | 2003-10-21 | 2005-01-12 | ローム株式会社 | Constant voltage power supply |
| CN102915069A (en) * | 2012-09-19 | 2013-02-06 | 中国兵器工业集团第二一四研究所苏州研发中心 | Overcurrent protection circuit of low dropout linear voltage stabilizer |
| CN204009654U (en) * | 2014-06-25 | 2014-12-10 | 万源市海铝科技有限公司 | For the current foldback circuit of linear voltage regulator |
| CN205212692U (en) * | 2015-10-22 | 2016-05-04 | 北京经纬恒润科技有限公司 | Low dropout regulator's current foldback circuit and low voltage difference linear constant voltage power supply |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110554724A (en) * | 2018-06-02 | 2019-12-10 | 丹阳恒芯电子有限公司 | overcurrent protection circuit |
| CN110069092A (en) * | 2019-04-18 | 2019-07-30 | 上海华力微电子有限公司 | The current foldback circuit of LDO circuit device and LDO circuit |
| US11204613B2 (en) | 2019-04-18 | 2021-12-21 | Shanghai Huali Microelectronics Corporation | LDO circuit device and overcurrent protection circuit thereof |
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| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| WW01 | Invention patent application withdrawn after publication |
Application publication date: 20180420 |
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| WW01 | Invention patent application withdrawn after publication |