CN107546724A - A kind of input overcurrent protective device - Google Patents
A kind of input overcurrent protective device Download PDFInfo
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- CN107546724A CN107546724A CN201710578762.3A CN201710578762A CN107546724A CN 107546724 A CN107546724 A CN 107546724A CN 201710578762 A CN201710578762 A CN 201710578762A CN 107546724 A CN107546724 A CN 107546724A
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Abstract
The present invention discloses a kind of input overcurrent protective device, including excessively stream sampling unit, over-current signal amplifying unit, excessively stream thresholding comparing unit, drive control unit and switch on and off unit；Excessively stream sampling unit gathers the over-current signal of input, and over-current signal input over-current signal amplifying unit is amplified, signal after amplification inputs excessively stream thresholding comparing unit compared with benchmark threshold signal, comparative result signal inputs drive control unit, by being turned on or off for drive control unit controlling switch break-make unit；Switch on and off unit uses PMOS, and the output end of comparing unit connects the grid of PMOS by diode；Leadage circuit is additionally provided between the voltage input end and ground of overcurrent protective device, the grid of PMOS is connected with leadage circuit, and leadage circuit forms drive control unit with diode.Leadage circuit electric discharge makes PMOS Delayed conducting, avoids the occurrence of the situation of PMOS vibration conducting, improves the reliability of the present apparatus；And it is simple in construction, cost is low.
Description
Technical field
The present invention relates to electronic circuit technology field, specifically a kind of input overcurrent protective device.
Background technology
In electronic circuit, in order to prevent input from introducing various interference, protection circuit, overcurrent protection electricity can be typically added
Road is to be set to prevent excessively stream.Existing input overcurrent protective device typically by sampling resistor, amplifier,
A reference source, comparator, controller and controlling switch composition, such a scenario-frame is complicated, and cost is higher；Some are set using low-loss
The circuit of meter, but cost is higher；Some are using control power supply control chip dutycycle, but power supply circuit loss is larger.
《A kind of Switching Power Supply current foldback circuit》（Application number 201320347931.X）Patent, have control in the circuit
IC chip, cost are higher；《A kind of low-loss new current foldback circuit of electronic product》（Application number
201220572956.5）Patent, the circuit structure is complicated, and cost is higher.
The content of the invention
It is an object of the invention to provide a kind of input overcurrent protective device, the apparatus structure is simple, cost is low, reliable
Property it is high, and excessively stream thresholding may be programmed.
The technical solution adopted for the present invention to solve the technical problems is：
A kind of input overcurrent protective device, including excessively stream sampling unit, over-current signal amplifying unit, excessively stream thresholding are more single
Member, drive control unit and switch on and off unit；
Excessively stream sampling unit gathers the over-current signal of input, and over-current signal input over-current signal amplifying unit is put
Greatly, the signal after amplification inputs excessively stream thresholding comparing unit compared with benchmark threshold signal, and the input of comparative result signal is driven
Dynamic control unit, by being turned on or off for drive control unit controlling switch break-make unit；
The excessively stream thresholding comparing unit uses comparator, the in-phase input end of the signal input comparator after amplification, partial pressure electricity
Resistance is in series in the voltage input end of the overcurrent protective device and the loop on ground with voltage-regulator diode, and voltage-regulator diode is formed
Inverting input of the reference voltage as comparator；
The switch on and off unit uses PMOS, and the output end of comparator connects the grid of PMOS, PMOS by diode
Voltage input end and voltage output end of the source electrode of pipe with drain electrode respectively as the overcurrent protective device；
Leadage circuit, grid and the leadage circuit phase of PMOS are additionally provided between the voltage input end and ground of overcurrent protective device
Even, leadage circuit forms drive control unit with diode.
The invention has the advantages that change the voltage stabilizing value of voltage-regulator diode by changing voltage-regulator diode, so as to change
Become the reference voltage of comparator inverting input, realize the programmable purpose of excessively stream thresholding；Drive control unit controls PMOS
Break-make, when there is excessively stream, gate pmos pole tension be more than shut-off threshold voltage, PMOS disconnect, inputted so as to reach
The effect of switch off current protection；After electric current recovers normal, leadage circuit is discharged, and grid voltage is slowly drop down to thresholding
Voltage, make PMOS Delayed conducting, avoid the occurrence of the situation of PMOS vibration conducting, improve the reliability of the present apparatus；And structure
Simply, cost is low.
Brief description of the drawings
The present invention is further described with reference to the accompanying drawings and examples：
Fig. 1 is the theory diagram of the present invention；
Fig. 2 is the circuit theory diagrams of the present invention.
Embodiment
With reference to shown in Fig. 1 and Fig. 2, a kind of input overcurrent protective device of present invention offer, including excessively stream sampling unit 1,
Over-current signal amplifying unit 2, excessively stream thresholding comparing unit 3, drive control unit 4 and switch on and off unit 5；
Excessively stream sampling unit 1 selects sampling resistor Rs, and the electric current for flowing through sampling resistor Rs forms sampled voltage Vs；Over-current signal is put
Big unit 2 is made up of amplifier N1, resistance R1 and R2, and sampled voltage Vs amplifies K times, after amplification through excessively stream signal amplification unit 2
Signal input excessively stream thresholding comparing unit 3 with benchmark threshold signal compared with, the excessively stream thresholding comparing unit 3 use than
Compared with device N2, the in-phase input end of the signal input comparator N2 after amplification, divider resistance R3 and voltage-regulator diode V1 is in series
The voltage input end Vin of the overcurrent protective device and the reference voltage Vr conducts that in the loop on ground, voltage-regulator diode V1 is formed
Comparator N2 inverting input；Comparator N2 comparative result signal input drive control unit, by drive control unit control
Switch on and off unit 5 processed is turned on or off；
The switch on and off unit 5 uses PMOS V3, and comparator N2 output end is by diode V4 connection PMOSs V3's
Grid, PMOS V3 source electrode and the voltage input end Vin and voltage output end that drain respectively as the overcurrent protective device
Vout；
Leadage circuit is additionally provided between the voltage input end Vin and ground of overcurrent protective device, leadage circuit includes diode V2, electricity
Resistance R4, electric capacity C1 and resistance R5, diode V2 are connected Vin, other end connection PMOS V3 grid with one end after resistance R4 parallel connections
Pole, electric capacity C1 latter end ground connection in parallel with resistance R5, the other end are connected PMOS V3 grid；Leadage circuit and diode V4 structures
Into drive control unit 4.
When input current is more than overcurrent numerical value Vr/ (K*Rs) of setting, then Vs*K is more than Vr, comparator N2 outputs
High level, the voltage is almost equal with input voltage vin, is designated as Vin2, electricity of the Vin2 after diode V4 tube voltage drop Vd
Press as Vin2-Vd, now PMOS V3 grid voltage Vg=Vin2-Vd, PMOS V3 grid step voltages Vg is much larger than shutoff door
Voltage limit, PMOS V3 disconnect, so as to have the function that to input overcurrent shut-off protection.PMOS V3 disconnects, when electric current recovers
After normal, electric capacity C1 is discharged by resistance R5, and elapsed time t=R5*C1*ln (Vin2/ (Vin2-Vth-0.7)) makes Vg
It is slowly drop down to threshold voltage Vth, VS*K and is less than Vr, comparator N2 output low levels, PMOS V3 grid step voltage is equal to V3's
Threshold voltage Vth, PMOS V3 are turned on, so as to which input recovers Normal on state.
Discharge time t is the PMOS V3 delay opening time after power supply excessively stream is recovered, and avoids electric current and recovers normal
PMOS V3 vibrations afterwards are opened.
The above described is only a preferred embodiment of the present invention, any formal limitation not is made to the present invention；Appoint
What those skilled in the art, without departing from the scope of the technical proposal of the invention, all using the side of the disclosure above
Method and technology contents make many possible changes and modifications to technical solution of the present invention, or are revised as the equivalent reality of equivalent variations
Apply example.Therefore, every content without departing from technical solution of the present invention, the technical spirit according to the present invention are done to above example
Any simple modification, equivalent substitution, equivalence changes and modification, still fall within the range of technical solution of the present invention protects.
Claims (1)
1. a kind of input overcurrent protective device, it is characterised in that including excessively stream sampling unit, over-current signal amplifying unit, mistake
Flow thresholding comparing unit, drive control unit and switch on and off unit；
Excessively stream sampling unit gathers the over-current signal of input, and over-current signal input over-current signal amplifying unit is put
Greatly, the signal after amplification inputs excessively stream thresholding comparing unit compared with benchmark threshold signal, and the input of comparative result signal is driven
Dynamic control unit, by being turned on or off for drive control unit controlling switch break-make unit；
The excessively stream thresholding comparing unit uses comparator, the in-phase input end of the signal input comparator after amplification, partial pressure electricity
Resistance is in series in the voltage input end of the overcurrent protective device and the loop on ground with voltage-regulator diode, and voltage-regulator diode is formed
Inverting input of the reference voltage as comparator；
The switch on and off unit uses PMOS, and the output end of comparator connects the grid of PMOS, PMOS by diode
Voltage input end and voltage output end of the source electrode of pipe with drain electrode respectively as the overcurrent protective device；
Leadage circuit, grid and the leadage circuit phase of PMOS are additionally provided between the voltage input end and ground of overcurrent protective device
Even, leadage circuit forms drive control unit with diode.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710578762.3A CN107546724A (en) | 2017-07-17 | 2017-07-17 | A kind of input overcurrent protective device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710578762.3A CN107546724A (en) | 2017-07-17 | 2017-07-17 | A kind of input overcurrent protective device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN107546724A true CN107546724A (en) | 2018-01-05 |
Family
ID=60970383
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201710578762.3A Pending CN107546724A (en) | 2017-07-17 | 2017-07-17 | A kind of input overcurrent protective device |
Country Status (1)
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| CN (1) | CN107546724A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111697547A (en) * | 2020-06-19 | 2020-09-22 | 湖南一二三智能科技有限公司 | Power-off equipment and method |
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| CN204156500U (en) * | 2014-10-10 | 2015-02-11 | 深圳市英威腾电气股份有限公司 | Overcurrent-overvoltage protecting circuit |
| CN204205545U (en) * | 2014-09-30 | 2015-03-11 | 深圳中兴力维技术有限公司 | Power overcurrent protection circuit |
| CN104577996A (en) * | 2014-12-26 | 2015-04-29 | 东莞钜威新能源有限公司 | Power supply over-current protection circuit based on integrated circuit |
| CN104617546A (en) * | 2015-02-13 | 2015-05-13 | 北京豪沃尔科技发展股份有限公司 | Output overcurrent and short circuit protection circuit |
| CN105743059A (en) * | 2016-02-19 | 2016-07-06 | 中国兵器工业集团第二一四研究所苏州研发中心 | Output over-current protection circuit formed by reference source and resistor |
| CN106603050A (en) * | 2016-12-15 | 2017-04-26 | 苏州捷芯威半导体有限公司 | Integrated semiconductor power switching device |
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2017
- 2017-07-17 CN CN201710578762.3A patent/CN107546724A/en active Pending
Patent Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7477502B1 (en) * | 2004-03-30 | 2009-01-13 | Emc Corporation | Method and system for providing fault protection in a power supply system |
| CN201536253U (en) * | 2009-09-18 | 2010-07-28 | 深圳市同洲电子股份有限公司 | USB overcurrent detection and control circuit |
| CN201937235U (en) * | 2010-12-17 | 2011-08-17 | 西安奇维测控科技有限公司 | Overcurrent protection circuit |
| CN102938797A (en) * | 2012-11-05 | 2013-02-20 | Tcl通讯（宁波）有限公司 | Current detection and control device for mobile terminal |
| CN104331141A (en) * | 2013-07-22 | 2015-02-04 | 纬创资通股份有限公司 | Overcurrent protection circuit and server thereof |
| CN204205545U (en) * | 2014-09-30 | 2015-03-11 | 深圳中兴力维技术有限公司 | Power overcurrent protection circuit |
| CN204156500U (en) * | 2014-10-10 | 2015-02-11 | 深圳市英威腾电气股份有限公司 | Overcurrent-overvoltage protecting circuit |
| CN104577996A (en) * | 2014-12-26 | 2015-04-29 | 东莞钜威新能源有限公司 | Power supply over-current protection circuit based on integrated circuit |
| CN104617546A (en) * | 2015-02-13 | 2015-05-13 | 北京豪沃尔科技发展股份有限公司 | Output overcurrent and short circuit protection circuit |
| CN105743059A (en) * | 2016-02-19 | 2016-07-06 | 中国兵器工业集团第二一四研究所苏州研发中心 | Output over-current protection circuit formed by reference source and resistor |
| CN106603050A (en) * | 2016-12-15 | 2017-04-26 | 苏州捷芯威半导体有限公司 | Integrated semiconductor power switching device |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111697547A (en) * | 2020-06-19 | 2020-09-22 | 湖南一二三智能科技有限公司 | Power-off equipment and method |
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Application publication date: 20180105 |
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| RJ01 | Rejection of invention patent application after publication |