CN206339589U - Current detection circuit - Google Patents
Current detection circuit Download PDFInfo
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- CN206339589U CN206339589U CN201621379251.6U CN201621379251U CN206339589U CN 206339589 U CN206339589 U CN 206339589U CN 201621379251 U CN201621379251 U CN 201621379251U CN 206339589 U CN206339589 U CN 206339589U
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Abstract
The utility model is related to current detection circuit, including sample circuit, sample circuit includes FET and sampling resistor Rsence, FET includes grid, drain electrode, source electrode and current detecting output stage, detecting electrode is connected with the current detecting output stage, the source ground of FET, the detecting electrode of the FET is connected with one end of the sampling resistor Rsence, the other end ground connection of the sampling resistor Rsence, electric current is flowed into from drain electrode, flowed out respectively from detecting electrode and source electrode, most of electric current flows out from source electrode, fraction electric current flows out from detecting electrode, information of voltage is converted into by sampling resistor Rsence.The utility model realizes small-power loss, the conversion of high-precision electric current to voltage signal, is not influenced by temperature by being provided with the FET of the detecting electrode of electric current, sampling precision height.
Description
Technical field
The utility model is related to the technical field of current detection circuit, more specifically current detection circuit.
Background technology
Field-effect transistor (Field Effect Transistor abridge (FET)) abbreviation FET.Mainly there are two kinds
Type (junction FET-JFET) and Metal-Oxide Semiconductor FET (metal-oxide semiconductor
FET, abbreviation MOS-FET).Participate in conductive by majority carrier, also referred to as unipolar transistor.It belongs to voltage-controlled type and partly led
Body device.With input resistance is high, noise is small, low in energy consumption, dynamic range big, be easily integrated, without secondary-breakdown phenomenon, safety
The advantages of workspace field width.
General FET is in driving application, it is necessary to which external resistance can just do current detecting；As shown in figure 1, leading back
Small resistance high-power resistance is sealed in road as current sample, it converts electrical current into voltage signal and supplied again after operation amplifier
Rear class control circuit is given, a very big power attenuation is thus introduced；Directly sampled field-effect to reduce power attenuation
The conducting internal resistance of pipe as current sampling resistor, as shown in Fig. 2 but due to FET conducting internal resistance with junction temperature change compared with
Often current sample is forbidden greatly, variation with temperature, and detection electric current has very large deviation.
Therefore, it is necessary to design a kind of current detection circuit, realize low power consumption, high-precision current detecting, at the same not by
The influence of temperature, sampling precision is high.
Utility model content
The purpose of this utility model is to overcome the defect of prior art there is provided current detection circuit.
To achieve the above object, the utility model uses following technical scheme：Current detection circuit, including sample circuit,
The sample circuit include FET and sampling resistor Rsence, the FET include grid, drain electrode, source electrode and
Detecting electrode is connected with current detecting output stage, the current detecting output stage, between the detecting electrode and the source electrode
Provided with division board, the source ground of the FET, the detecting electrode of the FET and the sampling resistor Rsence
One end connection, the sampling resistor Rsence the other end ground connection, electric current from drain electrode flow into, respectively from detecting electrode and source
Pole is flowed out, and most of electric current flows out from source electrode, and fraction electric current flows out from detecting electrode, is converted into by sampling resistor Rsence
Information of voltage.
Its further technical scheme is：The electric current of the detecting electrode and the pass that the electric current of the drain electrode is that equal proportion changes
System.
Its further technical scheme is：The source electrode is sheet metal, and the source electrode is provided with draws for the detecting electrode
Region.
Its further technical scheme is：The sampling resistor Rsence is small-power resistance.
Its further technical scheme is：The current detection circuit also includes amplifying circuit, and the amplifying circuit receives institute
The information of voltage of sampling resistor output is stated, output is amplified to the information of voltage.
Its further technical scheme is：The amplifying circuit includes in-phase amplifier, the positive input of the in-phase amplifier
End is connected by resistance R1 with one end of the sampling resistor Rsence；The negative input end of the in-phase amplifier passes through current limliting electricity
Hinder R3 ground connection.
Its further technical scheme is：The filter of ground connection is connected between the positive input terminal and resistance R1 of the in-phase amplifier
Ripple electric capacity C1, the output end of the in-phase amplifier is connected with feedback resistance R2, and one end of the feedback resistance R2 is connected to institute
State between current-limiting resistance R3 and the negative input end of in-phase amplifier.
The beneficial effect of the utility model compared with prior art is：Current detection circuit of the present utility model, by setting
The FET with detecting electrode is put, flowing through the electric current and detection electric current of FET has certain equal proportion relation, on the spot
When effect pipe flows through certain electric current, then detect electric current due to the into certain proportionate relationship of the electric current with FET, detection electricity
Stream flows through sampling resistor Rsence, and current signal is converted into voltage signal, then volt value after being amplified by in-phase amplifier and
The electric current of FET realizes small-power loss, the conversion of high-precision electric current to voltage signal, no into certain proportionate relationship
It is influenced by temperature, sampling precision is high.
The utility model is further described with specific embodiment below in conjunction with the accompanying drawings.
Brief description of the drawings
Fig. 1 is the circuit theory diagrams of the first existing current detection circuit；
Fig. 2 is the circuit theory diagrams of existing second of current detection circuit；
The circuit theory diagrams for the current detection circuit that Fig. 3 provides for the utility model specific embodiment；
The structural representation for the FET that Fig. 4 provides for the utility model specific embodiment.
Embodiment
In order to more fully understand technology contents of the present utility model, with reference to specific embodiment to skill of the present utility model
Art scheme is further described and illustrated, but is not limited to this.
Specific embodiment as shown in Figure 3 and Figure 4, the current detection circuit that the present embodiment is provided, can be used in electric current
Detect or be used in during current detecting is transformed into during voltage detecting, realize low power consumption, high-precision electric current
Detection, while not being influenced by temperature, sampling precision is high.
Current detection circuit, it includes sample circuit, and the sample circuit includes FET and sampling resistor
Rsence, the FET Q1 include connecting on grid, drain electrode, source electrode and current detecting output stage, current detecting output stage
It is connected to detecting electrode, FET Q1 source ground, FET Q1 detecting electrode and sampling resistor Rsence one end
Connection, sampling resistor Rsence other end ground connection, electric current is flowed into from drain electrode, is flowed out respectively from detecting electrode and source electrode, greatly
Portion of electrical current is flowed out from source electrode, and fraction electric current is flowed out from detecting electrode, and information of voltage is converted into by sampling resistor Rsence.
Above-mentioned FET Q1 grid and source electrode front draw, drain electrode overleaf draw, detecting electrode then according to
It is attached on source electrode, the change of detecting electrode and drain current is synchronous.
Further, the electric current of the detecting electrode and the relation that the electric current of the source-drain electrode is equal proportion change.
When detecting curent change, due to the change of temperature, can cause to detect current drift, in the present embodiment, the electric current of detecting electrode and
The equal current proportion change of source electrode, therefore, when detecting electric current, the electric current of detecting electrode is also to change simultaneously with drain current,
It is more accurate and more stable.
In the present embodiment, detecting electrode is directly drawn from source electrode portion, with identical driving voltage, for respective
The area ratio relation of chip so that the electric current always inputted according to respective area ratio relation, be divided into two-way electric current respectively from
Source electrode and detecting electrode outflow, can be with the home court advamtageg pipe without addition detecting electrode by adjusting area ratio relation
Q1 equal current proportion change, for temperature voltage change influence very little, can reach synchronous purpose.
Further, division board is provided between detecting electrode and the source electrode.The division board is used for isolation detection electrode
It is source electrode and detecting electrode is not operationally interfered with each other with detection power supply pole.
In the present embodiment, source electrode is sheet metal, and above-mentioned source electrode is provided with the region drawn for detecting electrode, by increasing
Plus detecting electrode, sampling precision is lifted, meanwhile, the area ratio between detecting electrode and the respective chip of source electrode can be adjusted,
So as to reduce whole FET Q1 in the power consumption with process.
Certainly, in other embodiment, above-mentioned source electrode can also be the hard goods of other shapes.
The FET Q1 of above-mentioned powered current detection functionality is in use, because flow into FET Q1 electric current Id and inspection
Surveying the detection electric current Is of electrode has certain equal proportion relation, i.e.,：K=Id/Is, K values here are by source electrode and detecting electrode
Between area ratio determine, when FET Q1 flows through certain electric current Id, then the detection electric current Is of detecting electrode and
FET Q1 electric current Id is flowed into certain proportionate relationship, i.e. Is=Id/K, detection electric current Is flows through small-power resistance
Rsence, voltage signal is converted to by current signal, because this voltage signal volt value is smaller, therefore is put again by in-phase amplifier
Volt value after big is Uo=(1+R2/R3) * Is*Rsence, and this voltage signal and the electric current Id for flowing into FET Q1 are into certain
Proportionate relationship, it is achieved that small-power loss, the conversion of high-precision electric current to voltage signal.
The FET Q1 of above-mentioned powered current detection functionality, by connecting a detecting electrode on source electrode, will be flowed into
The electric current of FET Q1 drain electrode is divided into two-way, and electric current flows out from detecting electrode all the way, and another road is flowed out from source electrode, by adjusting
The ratio between the area ratio of detecting electrode and source electrode, adjustment two-way electric current is saved, detection electric current and drain current equal proportion are same
Shi Bianhua, adjustment is smaller by the electric current of detecting electrode, and by adding amplifier, the information of voltage of detection is amplified, real
Existing low power consumption, high-precision current detecting, while not being influenced by temperature, sampling precision is high, more stablizes.
In above-mentioned current detection circuit, the detection electric current for flowing through FET Q1 electric current Id and being flowed out from detecting electrode
Is has certain equal proportion relation, i.e.,：K=Id/Is, when FET Q1 flows through certain electric current Id, then detects electric current Is
Due to the proportionate relationship into certain with Id electric currents, i.e. Is=Id/K, detection electric current Is flows through sampling resistor Rsence, and electric current is believed
Number be converted to voltage signal.
Further, sampling resistor Rsence is small-power resistance.
Specifically, above-mentioned sampling resistor Rsence is small-power Chip-R, it is certainly, above-mentioned in other embodiment
Sampling resistor Rsence can be the low power resistance of small resistance.
Further, current detection circuit also includes amplifying circuit, and amplifying circuit receives the voltage of sampling resistor output
Information, output display is amplified to information of voltage.Detection electric current Is flows through sampling resistor Rsence, and current signal is converted to
Voltage signal, because this voltage signal volt value is smaller, therefore after amplifying again by amplifying circuit, realizes small-power loss, high
Conversion of the electric current of precision to voltage signal.
In addition, amplifying circuit includes in-phase amplifier, the positive input terminal of in-phase amplifier passes through resistance R1 and sampling resistor
Rsence one end connection；The negative input end of the in-phase amplifier is grounded by current-limiting resistance R3.Detection electric current Is, which flows through, to be adopted
Sample resistance Rsence, voltage signal is converted to by current signal, because this voltage signal volt value is smaller, therefore is mutually put by same again
Volt value after big device amplification is Uo=(1+R2/R3) * Is*Rsence, this voltage signal proportionate relationship into certain with Id electric currents,
It is achieved that small-power loss, the conversion of high-precision electric current to voltage signal.
Specifically, the filter capacitor C1 of ground connection is connected between the positive input terminal and resistance R1 of in-phase amplifier, it is same mutually to put
The output end of big device is connected with feedback resistance R2, and feedback resistance R2 one end is connected to the negative of current-limiting resistance R3 and in-phase amplifier
Between input.
Above-mentioned current detection circuit, by being provided with the FET Q1 of detecting electrode, flows through FET Q1's
Electric current Id and detection electric current Is have certain equal proportion relation, i.e.,：K=Id/Is, when FET Q1 flows through certain electric current Id
When, then detect electric current Is due to the proportionate relationship into certain with FET Q1 electric current Id electric currents, i.e. Is=Id/K, detection electricity
Stream Is flows through sampling resistor Rsence, and current signal is converted into voltage signal, then the volt value after being amplified by in-phase amplifier
For Uo=(1+R2/R3) * Is*Rsence, voltage signal after the amplification of this in-phase amplifier and FET Q1 Id electric currents into
Certain proportionate relationship, realizes small-power loss, the conversion of high-precision electric current to voltage signal, is not influenced by temperature, adopts
Sample precision is high.
It is above-mentioned that technology contents of the present utility model are only further illustrated with embodiment, in order to which reader is easier to understand,
But embodiment of the present utility model is not represented and is only limitted to this, and any technology done according to the utility model extends or recreated,
By protection of the present utility model.Protection domain of the present utility model is defined by claims.
Claims (7)
1. current detection circuit, it is characterised in that including sample circuit, the sample circuit includes FET and sampling electricity
Rsence is hindered, the FET includes grid, drain electrode, source electrode and current detecting output stage, the current detecting output stage
On be connected with detecting electrode, between the detecting electrode and the source electrode be provided with division board, the source ground of the FET,
The detecting electrode of the FET is connected with one end of the sampling resistor Rsence, and the sampling resistor Rsence's is another
End ground connection, electric current is flowed into from drain electrode, is flowed out respectively from detecting electrode and source electrode, most of electric current flows out from source electrode, fraction
Electric current is flowed out from detecting electrode, and information of voltage is converted into by sampling resistor Rsence.
2. current detection circuit according to claim 1, it is characterised in that the electric current of the detecting electrode and the drain electrode
Electric current be equal proportion change relation.
3. current detection circuit according to claim 2, it is characterised in that the source electrode is on sheet metal, the source electrode
Provided with the region drawn for the detecting electrode.
4. the current detection circuit according to any one of claims 1 to 3, it is characterised in that the sampling resistor Rsence
For small-power resistance.
5. current detection circuit according to claim 4, it is characterised in that the current detection circuit also includes amplification electricity
Road, the amplifying circuit receives the information of voltage of the sampling resistor output, and output is amplified to the information of voltage.
6. current detection circuit according to claim 5, it is characterised in that the amplifying circuit includes in-phase amplifier,
The positive input terminal of the in-phase amplifier is connected by resistance R1 with one end of the sampling resistor Rsence；It is described to amplify with phase
The negative input end of device is grounded by current-limiting resistance R3.
7. current detection circuit according to claim 6, it is characterised in that the positive input terminal of the in-phase amplifier and electricity
It is connected with the filter capacitor C1 of ground connection between resistance R1, the output end of the in-phase amplifier is connected with feedback resistance R2, described anti-
Feed resistance R2 one end is connected between the current-limiting resistance R3 and the negative input end of in-phase amplifier.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201621379251.6U CN206339589U (en) | 2016-12-15 | 2016-12-15 | Current detection circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201621379251.6U CN206339589U (en) | 2016-12-15 | 2016-12-15 | Current detection circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN206339589U true CN206339589U (en) | 2017-07-18 |
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ID=59300884
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201621379251.6U Active CN206339589U (en) | 2016-12-15 | 2016-12-15 | Current detection circuit |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106601818A (en) * | 2016-12-15 | 2017-04-26 | 深圳市锐骏半导体股份有限公司 | Current-detection-function provided field-effect transistor, current detection circuit and detection method |
| CN109387688A (en) * | 2018-11-26 | 2019-02-26 | 成都锐成芯微科技股份有限公司 | A kind of current detection circuit |
| WO2019056299A1 (en) * | 2017-09-22 | 2019-03-28 | 深圳传音通讯有限公司 | Circuit for measuring zero-voltage-drop current |
-
2016
- 2016-12-15 CN CN201621379251.6U patent/CN206339589U/en active Active
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106601818A (en) * | 2016-12-15 | 2017-04-26 | 深圳市锐骏半导体股份有限公司 | Current-detection-function provided field-effect transistor, current detection circuit and detection method |
| CN106601818B (en) * | 2016-12-15 | 2019-09-10 | 深圳市锐骏半导体股份有限公司 | The detection method of current detection circuit |
| WO2019056299A1 (en) * | 2017-09-22 | 2019-03-28 | 深圳传音通讯有限公司 | Circuit for measuring zero-voltage-drop current |
| CN109387688A (en) * | 2018-11-26 | 2019-02-26 | 成都锐成芯微科技股份有限公司 | A kind of current detection circuit |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| PE01 | Entry into force of the registration of the contract for pledge of patent right | ||
| PE01 | Entry into force of the registration of the contract for pledge of patent right |
Denomination of utility model: High speed driving stage electric current detecting circuit Effective date of registration: 20180719 Granted publication date: 20170718 Pledgee: Shenzhen SME financing Company limited by guarantee Pledgor: Shenzhen Rui Jun semiconductor Limited by Share Ltd Registration number: 2018990000573 |
|
| PC01 | Cancellation of the registration of the contract for pledge of patent right | ||
| PC01 | Cancellation of the registration of the contract for pledge of patent right |
Date of cancellation: 20190604 Granted publication date: 20170718 Pledgee: Shenzhen SME financing Company limited by guarantee Pledgor: Shenzhen Rui Jun semiconductor Limited by Share Ltd Registration number: 2018990000573 |
|
| PE01 | Entry into force of the registration of the contract for pledge of patent right | ||
| PE01 | Entry into force of the registration of the contract for pledge of patent right |
Denomination of utility model: Inverter of voltage polarity, detecting circuit and method of charge and discharge current of battery Effective date of registration: 20190604 Granted publication date: 20170718 Pledgee: Shenzhen SME financing Company limited by guarantee Pledgor: Shenzhen Rui Jun semiconductor Limited by Share Ltd Registration number: 2019990000511 |
|
| PC01 | Cancellation of the registration of the contract for pledge of patent right | ||
| PC01 | Cancellation of the registration of the contract for pledge of patent right |
Date of cancellation: 20201023 Granted publication date: 20170718 Pledgee: Shenzhen SME financing Company limited by guarantee Pledgor: SHENZHEN RUICHIPS SEMICONDUCTOR Co.,Ltd. Registration number: 2019990000511 |