CN102801294A - In-parallel sampling over-current protection circuit - Google Patents
In-parallel sampling over-current protection circuit Download PDFInfo
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- CN102801294A CN102801294A CN2012102652975A CN201210265297A CN102801294A CN 102801294 A CN102801294 A CN 102801294A CN 2012102652975 A CN2012102652975 A CN 2012102652975A CN 201210265297 A CN201210265297 A CN 201210265297A CN 102801294 A CN102801294 A CN 102801294A
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Abstract
The invention discloses an in-parallel sampling over-current protection circuit. The in-parallel sampling over-current protection circuit comprises a temperature-drift suppression circuit, an in-parallel sampling circuit, an output power component, a reference input end, a first output end and a second output end, wherein the temperature-drift suppression circuit consists of a first resistor, a first thermistor, a second resistor, a second thermistor and an operation amplifier; the in-parallel sampling circuit consists of a first switching tube, another second thermistor and a second resistor; the output power component is formed by N second switching tubes in a parallel connection manner; output current flows through the first output end and the second output end; when the output current is overlarge, voltage of a second input end of the operation amplifier is higher than voltage of a first input end, the signal level of the output end of the operation amplifier is changed, the first switching tube and the second switching tubes are disconnected to realize over-current protection; and the temperature-drift suppression circuit carries out compensation by the first thermistor and the second thermistor, and by voltage distribution between the first resistor and the first thermistor and voltage distribution between the second resistor and the second thermistor, a proportional relation is formed, and flexible adjustment of over-current protection points is realized.
Description
Technical field
The present invention relates to a kind of current foldback circuit, more specifically, relate to a kind of parallelly connected overcurrent sampling protective circuit with temperature stability, low-power consumption, it can be used for solid-state relay or solid-state power controller is inner, realizes the output overcurrent protection.
Background technology
Usually solid-state relay or solid-state power controller current foldback circuit adopt series connection sampling resistor mode to carry out.The weak point of this mode sampling resistor that is to connect has increased power consumption, and bigger its power consumption of Control current is big more, and temperature rise increases when causing the device operate as normal, and device reliability is produced certain influence.Therefore, develop multiple overcurrent sample circuit in the prior art, be used for the overcurrent protection of device.
In the overcurrent sample circuit that has been applied at present; Some adopts series connection sampling resistor mode (like constantan wire, manganese-copper filament), and some adopts the power Chip-R, and some employing has the intelligent MOSFET device of overcurrent sampling function; Some adopts temperature-sensitive device to pass through temperature sampling; Can play better action, but still have certain defective, mainly show:
1. series connection sample mode extra increase power consumption, thus the temperature rise of device increased, in application, heat radiation is required highlyer, homogeneity of product receives technogenic influence bigger, is unfavorable for producing in batches;
2. intelligent MOSFET is limited by device, and range of application is narrower, is difficult to adapt to the flexible Application of different voltages, different electric currents, and the adjustment of protection point is restricted;
3. the temperature-sensitive device sample mode belongs to indirect sampling, and reaction speed is slower, receives its consistency of technogenic influence relatively poor, and the overcurrent protection accuracy is lower.
Summary of the invention
Deficiency to above-mentioned prior art; The present invention proposes a kind of overcurrent sampling protective circuit with temperature stability, low-power consumption; This circuit adopts parallelly connected sampling resistor mode; Only constitute, have advantages such as low-power consumption, over-current protection point high conformity, easy batch process by regular tap pipe, thermistor, resistance and operational amplifier.
For realizing above-mentioned purpose, the present invention realizes through following technical scheme:
A kind of parallel connection sampling current foldback circuit, it is inner to be used for solid-state relay or solid-state power controller, it is characterized in that, comprising:
Reference input floats the input that suppresses circuit for temperature; Said temperature is floated the output that suppresses circuit and is connected with the input of parallelly connected sample circuit and the input of power output assembly respectively, and said parallelly connected sample circuit and said power output assembly and first output, second output are parallelly connected;
Wherein, parallelly connected sample circuit reduces the passage current of said parallelly connected sample circuit through series resistance, realizes low-power consumption; Temperature is floated the inhibition circuit, and through the dividing potential drop formation proportionate relationship of thermistor and resistance, the characteristic of utilizing thermistor to change with variations in temperature suppresses the influence of variations in temperature to said parallel connection sampling current foldback circuit; The power output assembly is composed in parallel by N switching tube;
Further, said parallelly connected sample circuit comprises:
First switching tube, second thermistor and second resistance; Said first switching tube, second end is connected with said first output; Said first switching tube the 3rd end is connected with said second thermistor, first end; Said second thermistor, second end is connected with said second resistance, first end, and said second resistance, second end is connected with said second output.
Further, said temperature is floated the inhibition circuit, comprising:
First resistance, first thermistor, second resistance, second thermistor and operational amplifier; Said first resistance, first end is connected with said reference input; Said first resistance, second end is connected and is connected with said operational amplifier first input end with said first thermistor, first end; The said first input end voltage of said operational amplifier is reference voltage, and said first thermistor, second end is connected with said second output, and said second resistance, first end is connected with said operational amplifier second input; Said second input terminal voltage of said operational amplifier is a sampled voltage; Said operational amplifier output terminal is that said temperature is floated the output that suppresses circuit, is connected with said first switching tube, first end, and said first switching tube, first end is the input of said parallelly connected sample circuit;
Further; Said power output assembly is made up of N second switch pipe; N is the natural number of 1-N; N said second switch pipe forms parallelly connected relation with said first output and said second output, and said operational amplifier output terminal is connected with N said second switch pipe first end, and said second switch first end is the input of said power output assembly;
Further, when said first switching tube was N type metal-oxide-semiconductor or P type metal-oxide-semiconductor, first end of said first switching tube, second end, the 3rd end were grid, drain electrode, source electrode;
Further, when said first switching tube was N type metal-oxide-semiconductor, N said second switch pipe was N type metal-oxide-semiconductor perhaps, perhaps is NPN type triode; When said first switching tube was P type metal-oxide-semiconductor, N said second switch pipe was P type metal-oxide-semiconductor perhaps;
When N said second switch pipe is triode; First end of said second switch pipe, second end, the 3rd end are base stage, collector electrode, emitter; When the N of institute said second switch pipe was metal-oxide-semiconductor, first end of said second switch pipe, second end, the 3rd end were grid, drain electrode, source electrode;
Further, said first thermistor and second thermistor are semistor;
Further, said operational amplifier can replace with comparator.
The parallelly connected current foldback circuit that the present invention adopts is compared with traditional overcurrent sample circuit, has following characteristics:
1. the present invention has adopted temperature to float the inhibition circuit; Dividing potential drop through thermistor and resistance forms proportionate relationship; The characteristics of utilizing thermistor to change with variations in temperature; Suppress the influence of variations in temperature to circuit, therefore in wider temperature range (as-55 ℃～125 ℃), the overcurrent sample circuit have certain stability (in ± 3%) and the over-current protection point consistency better;
2. the present invention makes the passage current of parallelly connected sample circuit significantly reduce through the mode of the big resistance of connecting, and realized low-power consumption, so device work temperature rise is little, and homogeneity of product is fine, is beneficial to batch process;
3. the present invention only is made up of regular tap pipe, thermistor, resistance and operational amplifier, and circuit is simple, has higher reliability.
Description of drawings
Fig. 1 is the parallel connection sampling current foldback circuit circuit diagram of the specific embodiment of the invention one;
Fig. 2 is the parallel connection sampling current foldback circuit circuit diagram of the specific embodiment of the invention two;
Fig. 3 is the parallel connection sampling current foldback circuit circuit diagram of the specific embodiment of the invention three.
The main element symbol description
Embodiment
Further specify technical scheme of the present invention below in conjunction with accompanying drawing and through specific embodiment.It is understandable that specific embodiment described herein only is used to explain the present invention, but not to qualification of the present invention.
Embodiment one
As shown in Figure 1, be the circuit diagram of the parallel connection of first embodiment of the invention sampling current foldback circuit, this invention is used for solid-state relay or solid-state power controller is inner, specifically comprises:
Temperature is floated the inhibition circuit, comprising: first resistance R 1, the first thermistor RT1, second resistance R 2, the second thermistor RT2 and operational amplifier OAMP; The parallel connection sample circuit comprises: the first switching tube Q1, the second thermistor RT2 and second resistance R 2; The power output assembly is composed in parallel by N second switch pipe, in the present embodiment, as preferably, selects N=2, and promptly two second switch pipe parallel connections are respectively Q2 and Q3; Reference input Ref, the first output end vo ut1 and the second output end vo ut2.
Said temperature is floated and is suppressed that first resistance R, 1 first end is connected with said reference input Ref described in the circuit; Said first resistance R, 1 second end is connected with the said first thermistor RT1, first end and is connected with said operational amplifier OAMP first input end IN1; The said first input end IN1 of said operational amplifier OAMP voltage is reference voltage, and the said first thermistor RT1, second end is connected with the said second output end vo ut2.
The first switching tube Q1 described in the said parallelly connected sample circuit, the said second thermistor RT2 and 2 series connection of said second resistance R; The said first switching tube Q1, second end is connected with the said first output end vo ut1; Said second resistance R, 2 second ends are connected with the said second output end vo ut2; Said second resistance R, 2 first ends are connected with the said operational amplifier OAMP second input IN2, and the said second input IN2 voltage of said operational amplifier OAMP is sampled voltage.
Said operational amplifier OAMP output OUT is connected with first end of the said first switching tube Q1; Be connected with said second switch pipe first end; The quantity of said second switch pipe is variable; As preferably, in the present embodiment, said second switch pipe is respectively Q2 and Q3; The output OUT of said operational amplifier OAMP is connected with first end of said second switch pipe Q2 and Q3, and said second switch pipe Q2 and Q3 form parallelly connected relation with said first output end vo ut1 and the said second output end vo ut2.
Said parallelly connected sample circuit forms parallelly connected relation with said first output end vo ut1 and the said second output end vo ut2; The said second thermistor RT2 in the said parallelly connected sample circuit and the resistance of second resistance R 2 are much larger than the output resistance (more than 10 times) of said second switch pipe Q2 and Q3; Therefore the electric current of said parallelly connected sample circuit path is very little; Its power consumption can be ignored, thereby realizes the sampling of low-power consumption overcurrent.
Output current flow through said first output end vo ut1 and the said second output end vo ut2, the said first input end IN1 of said operational amplifier OAMP is an in-phase input end, the said second input IN2 of said operational amplifier OAMP is an inverting input; When operate as normal, that is to say and work as electric current just often; Said sampled voltage is less than said reference voltage, and promptly said reverse voltage is less than said in-phase voltage, and therefore the said output OUT of said operational amplifier OAMP is a high level; When said output current is excessive; Said sampled voltage will be greater than said reference voltage, and promptly said reverse voltage is greater than said in-phase voltage, and the said output OUT of then said operational amplifier OAMP signal level becomes low level; Make said first switching tube Q1 and said second switch pipe Q2 and Q3 turn-off, realize overcurrent protection.
Because the output resistance of said second switch pipe Q2 and Q3 causes said parallelly connected sample circuit voltage with variations in temperature with variations in temperature, so the present invention adopts temperature to float the generation that the inhibition circuit suppresses this situation.Said temperature is floated the inhibition circuit and is compensated through said first thermistor RT1 and the said second thermistor RT2, and said first thermistor RT1 and the said second thermistor RT2 are semistor.
When the output resistance of said second switch pipe Q2 and Q3 during with temperature change; The voltage of said parallelly connected sample circuit changes, and causes said sampled voltage also to change, and the consistency of over-current protection point is just relatively poor like this; When through said first resistance and the said first thermistor dividing potential drop; Said second resistance and the said second thermistor dividing potential drop form proportionate relationship, the characteristics of utilizing thermistor to change with variation of temperature; Make the variation of said sampled voltage and said reference voltage consistent with the variation that variations in temperature produces, realize the flexible adjustment of over-current protection point with said second switch pipe Q2 and Q3.In addition, said first thermistor RT1 and the said second thermistor RT2 also play the effect that temperature suppresses, and realize the stability of over-current protection point in full operating temperature range.
In the present embodiment, the first switching tube Q1 is a N type metal-oxide-semiconductor, and said second switch pipe Q2 and Q3 or be N type metal-oxide-semiconductor perhaps are NPN type triode, and as preferably, pipe Q2 of second switch described in the present embodiment and Q3 are N type metal-oxide-semiconductor.First end, second end, the 3rd end of the said first switching tube Q1, said second switch pipe Q2 and Q3 are grid, drain electrode, source electrode.
Embodiment two
As shown in Figure 2, be the circuit diagram of the parallel connection of second embodiment of the invention sampling current foldback circuit, this invention is used for solid-state relay or solid-state power controller is inner, specifically comprises:
Temperature is floated the inhibition circuit, comprising: first resistance R 1, the first thermistor RT1, second resistance R 2, the second thermistor RT2 and operational amplifier OAMP; The parallel connection sample circuit comprises: the first switching tube Q1, the second thermistor RT2 and second resistance R 2; The power output assembly is composed in parallel by N second switch pipe, in the present embodiment, as preferably, selects N=3, and promptly three second switch pipe parallel connections are respectively Q2, Q3 and Q4; Reference input Ref, the first output end vo ut1 and the second output end vo ut2.
Said temperature is floated and is suppressed that first resistance R, 1 first end is connected with said reference input Ref described in the circuit; Said first resistance R, 1 second end is connected with the said first thermistor RT1, first end and is connected with said operational amplifier OAMP first input end IN1; The said first input end IN1 of said operational amplifier OAMP voltage is reference voltage, and the said first thermistor RT1, second end is connected with the said second output end vo ut2.
The first switching tube Q1 described in the said parallelly connected sample circuit, the said second thermistor RT2 and 2 series connection of said second resistance R; The said first switching tube Q1, second end is connected with the said first output end vo ut1; Said second resistance R, 2 second ends are connected with the said second output end vo ut2; Said second resistance R, 2 first ends are connected with the said operational amplifier OAMP second input IN2, and the said second input IN2 voltage of said operational amplifier OAMP is sampled voltage.
Said operational amplifier OAMP output OUT is connected with first end of the said first switching tube Q1; Be connected with said second switch pipe first end; The quantity of said second switch pipe is variable; As preferably, in the present embodiment, said second switch pipe is respectively Q2, Q3 and Q4; The output OUT of said operational amplifier OAMP is connected with first end of said second switch pipe Q2, Q3 and Q4, and said second switch pipe Q2, Q3 and Q4 form parallelly connected relation with said first output end vo ut1 and the said second output end vo ut2.
Said parallelly connected sample circuit forms parallelly connected relation with said first output end vo ut1 and the said second output end vo ut2; The said second thermistor RT2 in the said parallelly connected sample circuit and the resistance of second resistance R 2 are much larger than the output resistance (more than 10 times) of said second switch pipe Q2, Q3 and Q4; Therefore the electric current of said parallelly connected sample circuit path is very little; Its power consumption can be ignored, thereby realizes the sampling of low-power consumption overcurrent.
Output current flow through said first output end vo ut1 and the said second output end vo ut2, the said first input end IN1 of said operational amplifier OAMP is an inverting input, the said second input IN2 of said operational amplifier OAMP is an in-phase input end; When operate as normal, that is to say and work as electric current just often; Said sampled voltage is less than said reference voltage, and promptly said in-phase voltage is less than said reverse voltage, and therefore the said output OUT of said operational amplifier OAMP is a low level; When said output current is excessive; Said sampled voltage will be greater than said reference voltage, and promptly said in-phase voltage is greater than said reverse voltage, and the said output OUT of then said operational amplifier OAMP signal level uprises level; Make said first switching tube Q1 and said second switch pipe Q2, Q3 and Q4 turn-off, realize overcurrent protection.
Because the output resistance of said second switch pipe Q2, Q3 and Q4 causes said parallelly connected sample circuit voltage with variations in temperature with variations in temperature, so the present invention adopts temperature to float the generation that the inhibition circuit suppresses this situation.Said temperature is floated the inhibition circuit and is compensated through said first thermistor RT1 and the said second thermistor RT2, and said first thermistor RT1 and the said second thermistor RT2 are semistor.
When the output resistance of said second switch pipe Q2, Q3 and Q4 during with temperature change; The voltage of said parallelly connected sample circuit changes, and causes said sampled voltage also to change, and the consistency of over-current protection point is just relatively poor like this; When through said first resistance and the said first thermistor dividing potential drop; Said second resistance and the said second thermistor dividing potential drop form proportionate relationship, the characteristics of utilizing thermistor to change with variation of temperature; Make the variation of said sampled voltage and said reference voltage consistent with the variation that variations in temperature produces, realize the flexible adjustment of over-current protection point with said second switch pipe Q2, Q3 and Q4.In addition, said first thermistor RT1 and the said second thermistor RT2 also play the effect that temperature suppresses, and realize the stability of over-current protection point in full operating temperature range.
In the present embodiment, the first switching tube Q1 is a P type metal-oxide-semiconductor, and said second switch pipe Q2, Q3 and Q4 or be P type metal-oxide-semiconductor perhaps are the positive-negative-positive triode, and as preferably, the pipe of second switch described in present embodiment Q2, Q3 and Q4 are P type metal-oxide-semiconductor.First end, second end, the 3rd end of the said first switching tube Q1, said second switch pipe Q2, Q3 and Q4 are grid, drain electrode, source electrode.
Embodiment three
As shown in Figure 3, be the circuit diagram of the parallel connection of third embodiment of the invention sampling current foldback circuit, this invention is used for solid-state relay or solid-state power controller is inner, specifically comprises:
Temperature is floated the inhibition circuit, comprising: first resistance R 1, the first thermistor RT1, second resistance R 2, second thermistor RT2 and the comparator; The parallel connection sample circuit comprises: the first switching tube Q1, the second thermistor RT2 and second resistance R 2; The power output assembly is composed in parallel by N second switch pipe, in the present embodiment, as preferably, selects N=1, i.e. a second switch pipe Q2; Reference input Ref, the first output end vo ut1 and the second output end vo ut2.
Said temperature is floated and is suppressed that first resistance R, 1 first end is connected with said reference input Ref described in the circuit; Said first resistance R, 1 second end is connected with the said first thermistor RT1, first end and is connected with said comparator first input end IN1; The said first input end IN1 of said comparator C omparator voltage is reference voltage, and the said first thermistor RT1, second end is connected with the said second output end vo ut2.
The first switching tube Q1 described in the said parallelly connected sample circuit, the said second thermistor RT2 and 2 series connection of said second resistance R; The said first switching tube Q1, second end is connected with the said first output end vo ut1; Said second resistance R, 2 second ends are connected with the said second output end vo ut2; Said second resistance R, 2 first ends are connected with the said comparator second input IN2, and the said second input IN2 voltage of said comparator is sampled voltage.
Said comparator output terminal OUT is connected with first end of the said first switching tube Q1; The output OUT of said comparator is connected with first end of said second switch pipe Q2, and said second switch pipe Q2 forms parallelly connected relation with said first output end vo ut1 and the said second output end vo ut2.
Said parallelly connected sample circuit forms parallelly connected relation with said first output end vo ut1 and the said second output end vo ut2; The said second thermistor RT2 in the said parallelly connected sample circuit and the resistance of second resistance R 2 are much larger than the output resistance (more than 10 times) of said second switch pipe Q2; Therefore the electric current of said parallelly connected sample circuit path is very little; Its power consumption can be ignored, thereby realizes the sampling of low-power consumption overcurrent.
Output current flow through said first output end vo ut1 and the said second output end vo ut2; When operate as normal, that is to say and work as electric current just often, said sampled voltage is less than said reference voltage, and therefore the said output OUT of said comparator is a high level; When said output current is excessive; Said sampled voltage will be greater than said reference voltage, and promptly said reverse voltage is greater than said in-phase voltage, the said output OUT of then said comparator signal level step-down level; Make said first switching tube Q1 and said second switch pipe Q2 turn-off, realize overcurrent protection.
Because the output resistance of said second switch pipe Q2 causes said parallelly connected sample circuit voltage with variations in temperature with variations in temperature, so the present invention adopts temperature to float the generation that the inhibition circuit suppresses this situation.Said temperature is floated the inhibition circuit and is compensated through said first thermistor RT1 and the said second thermistor RT2, and said first thermistor RT1 and the said second thermistor RT2 are semistor.
When the output resistance of said second switch pipe Q2 during with temperature change; The voltage of said parallelly connected sample circuit changes, and causes said sampled voltage also to change, and the consistency of over-current protection point is just relatively poor like this; When through said first resistance and the said first thermistor dividing potential drop; Said second resistance and the said second thermistor dividing potential drop form proportionate relationship, the characteristics of utilizing thermistor to change with variation of temperature; Make the variation of said sampled voltage and said reference voltage consistent with the variation that variations in temperature produces, realize the flexible adjustment of over-current protection point with said second switch pipe Q2.In addition, said first thermistor RT1 and the said second thermistor RT2 also play the effect that temperature suppresses, and realize the stability of over-current protection point in full operating temperature range.
In the present embodiment, the first switching tube Q1 is a N type metal-oxide-semiconductor, and said second switch pipe Q2 or be N type metal-oxide-semiconductor perhaps is a NPN type triode, and as preferably, the pipe of second switch described in present embodiment Q2 is a NPN type triode.Q1 first end of said first switching tube, second end, the 3rd end are grid, drain electrode, source electrode, and first end of said second switch pipe Q2, second end, the 3rd end are base stage, collector electrode, emitter.
The parallelly connected current foldback circuit that the present invention adopts is compared with traditional overcurrent sample circuit, has following characteristics:
1. the present invention has adopted temperature to float the inhibition circuit; Dividing potential drop through thermistor and resistance forms proportionate relationship; The characteristics of utilizing thermistor to change with variations in temperature; Suppress the influence of variations in temperature to circuit, therefore in wider temperature range (as-55 ℃～125 ℃), the overcurrent sample circuit have certain stability (in ± 3%) and the over-current protection point consistency better;
2. the present invention makes the passage current of parallelly connected sample circuit significantly reduce through the mode of the big resistance of connecting, and realized low-power consumption, so device work temperature rise is little, and homogeneity of product is fine, is beneficial to batch process;
3. the present invention only is made up of regular tap pipe, thermistor, resistance and operational amplifier, and circuit is simple, has higher reliability.
More than show and described basic principle of the present invention, principal character and advantage of the present invention.The technical staff of the industry should understand; The present invention is not restricted to the described embodiments; That describes in the foregoing description just explains principle of the present invention; The present invention also has various changes and modifications under the prerequisite that does not break away from spirit and scope of the invention, and these variations and improvement all fall in the scope of the invention that requires protection.The present invention requires protection range to be defined by appending claims and equivalent thereof.
Claims (8)
1. a parallel connection sampling current foldback circuit is used for solid-state relay or solid-state power controller inside, it is characterized in that, comprising:
Reference input floats the input that suppresses circuit for temperature; Said temperature is floated the output that suppresses circuit and is connected with the input of parallelly connected sample circuit and the input of power output assembly respectively, and said parallelly connected sample circuit and said power output assembly and first output, second output are parallelly connected;
Wherein, parallelly connected sample circuit reduces the passage current of said parallelly connected sample circuit through series resistance, realizes low-power consumption; Temperature is floated the inhibition circuit, and through the dividing potential drop formation proportionate relationship of thermistor and resistance, the characteristic of utilizing thermistor to change with variations in temperature suppresses the influence of variations in temperature to said parallel connection sampling current foldback circuit; The power output assembly is composed in parallel by N switching tube.
2. parallel connection sampling current foldback circuit according to claim 1 is characterized in that said parallelly connected sample circuit comprises:
First switching tube, second thermistor and second resistance; Said first switching tube, second end is connected with said first output; Said first switching tube the 3rd end is connected with said second thermistor, first end; Said second thermistor, second end is connected with said second resistance, first end, and said second resistance, second end is connected with said second output.
3. according to claim 1 or 2 described parallel connection sampling current foldback circuits, it is characterized in that said temperature is floated the inhibition circuit, comprising:
First resistance, first thermistor, second resistance, second thermistor and operational amplifier; Said first resistance, first end is connected with said reference input; Said first resistance, second end is connected and is connected with said operational amplifier first input end with said first thermistor, first end; The said first input end voltage of said operational amplifier is reference voltage, and said first thermistor, second end is connected with said second output, and said second resistance, first end is connected with said operational amplifier second input; Said second input terminal voltage of said operational amplifier is a sampled voltage; Said operational amplifier output terminal is that said temperature is floated the output that suppresses circuit, is connected with said first switching tube, first end, and said first switching tube, first end is the input of said parallelly connected sample circuit.
4. parallel connection sampling current foldback circuit according to claim 3; It is characterized in that; Said power output assembly is made up of N second switch pipe, and N is the natural number of 1-N, and N said second switch pipe forms parallelly connected relation with said first output and said second output; Said operational amplifier output terminal is connected with N said second switch pipe first end, and said second switch first end is the input of said power output assembly.
5. parallel connection sampling current foldback circuit according to claim 4 is characterized in that said first switching tube is N type metal-oxide-semiconductor or P type metal-oxide-semiconductor, and first end of said first switching tube, second end, the 3rd end are grid, drain electrode, source electrode.
6. parallel connection sampling current foldback circuit according to claim 4 is characterized in that,
When said first switching tube was N type metal-oxide-semiconductor, N said second switch pipe was N type metal-oxide-semiconductor perhaps, perhaps is NPN type triode; When said first switching tube was P type metal-oxide-semiconductor, N said second switch pipe was P type metal-oxide-semiconductor perhaps;
When N said second switch pipe is triode; First end of said second switch pipe, second end, the 3rd end are base stage, collector electrode, emitter; When the N of institute said second switch pipe was metal-oxide-semiconductor, first end of said second switch pipe, second end, the 3rd end were grid, drain electrode, source electrode.
7. parallel connection sampling current foldback circuit according to claim 4 is characterized in that said first thermistor and second thermistor are semistor.
8. parallel connection sampling current foldback circuit according to claim 4 is characterized in that said operational amplifier can replace with comparator.
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104993560A (en) * | 2015-06-23 | 2015-10-21 | 国网天津武清供电有限公司 | Charger circuit |
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| CN107979269A (en) * | 2017-11-08 | 2018-05-01 | 珠海格力电器股份有限公司 | Current foldback circuit |
| CN108493912A (en) * | 2018-04-09 | 2018-09-04 | 东莞赛微微电子有限公司 | A kind of current foldback circuit and device |
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| CN111337735A (en) * | 2020-02-17 | 2020-06-26 | 上海艾为电子技术股份有限公司 | Chip and current sampling circuit |
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Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20090039869A1 (en) * | 2007-08-08 | 2009-02-12 | Advanced Analogic Technologies, Inc. | Cascode Current Sensor For Discrete Power Semiconductor Devices |
| CN101470142A (en) * | 2007-12-27 | 2009-07-01 | 英业达股份有限公司 | Overcurrent detection circuit, decompression converter and overcurrent detection method |
| CN102208802A (en) * | 2010-06-29 | 2011-10-05 | 上海山景集成电路技术有限公司 | Power switching tube overcurrent detection and overcurrent protection circuit |
-
2012
- 2012-07-27 CN CN201210265297.5A patent/CN102801294B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20090039869A1 (en) * | 2007-08-08 | 2009-02-12 | Advanced Analogic Technologies, Inc. | Cascode Current Sensor For Discrete Power Semiconductor Devices |
| CN101470142A (en) * | 2007-12-27 | 2009-07-01 | 英业达股份有限公司 | Overcurrent detection circuit, decompression converter and overcurrent detection method |
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