CN109374945A - Current detection circuit - Google Patents
Current detection circuit Download PDFInfo
- Publication number
- CN109374945A CN109374945A CN201811059752.XA CN201811059752A CN109374945A CN 109374945 A CN109374945 A CN 109374945A CN 201811059752 A CN201811059752 A CN 201811059752A CN 109374945 A CN109374945 A CN 109374945A
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- CN
- China
- Prior art keywords
- operational amplifier
- resistor
- grid
- pmos tube
- drain electrode
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Classifications
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
- G01R19/0092—Arrangements for measuring currents or voltages or for indicating presence or sign thereof measuring current only
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- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Measurement Of Current Or Voltage (AREA)
Abstract
The invention discloses a kind of current detection circuits.Current detection circuit includes first resistor R1, the first operational amplifier, second operational amplifier, the first NMOS tube, second resistance R2, the first PMOS tube, the second PMOS tube and 3rd resistor R3.The electric current for being not easy to detect can be detected indirectly using current detection circuit of the invention.
Description
Technical field
The present invention relates to electronic technology field more particularly to current detection circuits.
Background technique
Electric current on some occasion routes is not easy directly to measure come it is necessary to going out current detecting by indirect mode
Come, devises current detection circuit thus.
Summary of the invention
Present invention seek to address that the deficiencies in the prior art, provide a kind of current detection circuit.
Current detection circuit, including first resistor R1, the first operational amplifier, second operational amplifier, the first NMOS tube,
Second resistance R2, the first PMOS tube, the second PMOS tube and 3rd resistor R3:
The positive input terminal of termination input a Vin and first operational amplifier of the first resistor R1, another termination second
The positive input terminal of operational amplifier；The positive input of first operational amplifier terminates one end of the first resistor R1, bears defeated
Enter one end of the source electrode for terminating first NMOS tube and the second resistance R2, output terminates the grid of first NMOS tube
Pole；The positive input of the second operational amplifier terminates one end of the first resistor R1, and negative input end and output terminate at one
Play the one end for meeting the second resistance R2 again；The grid of first NMOS tube connects the output end of first operational amplifier,
Drain electrode connects the grid of first PMOS tube and the grid of drain electrode and second PMOS tube, and source electrode connects first operation amplifier
One end of the negative input end of device and the second resistance R2；Termination first operational amplifier of the second resistance R2
The source electrode of negative input end and first NMOS tube, the negative input end and output end of another termination second operational amplifier；
The grid of first PMOS tube and drain electrode are connected together connects the drain electrode and second PMOS tube of first NMOS tube again
Grid, source electrode meet supply voltage VCC；
The grid of second PMOS tube connects the drain electrode of first NMOS tube and grid and the drain electrode of first PMOS tube, leakage
Pole connects one end of the 3rd resistor R3, and source electrode meets supply voltage VCC；Termination the 2nd PMOS of the 3rd resistor R3
The drain electrode of pipe, other end ground connection.
The voltage at the both ends the first resistor R1 first operational amplifier and first NMOS tube by being made of
Follower and the second operational amplifier constitute follower detected, the second resistance R2 is added in after detected
Upper generation electric current I2, then flowed out by the first PMOS tube mirror image to second PMOS tube and produced on given 3rd resistor R3
Raw voltage, the resistance value of the first resistor R1, the second resistance R2 and the 3rd resistor R3 are known, the thirds
Voltage VC on resistance R3 can be tested out, and counter roll back can indirectly go out the testing current on the first resistor R1
Come.
Detailed description of the invention
Fig. 1 is the circuit diagram of current detection circuit of the invention.
Specific embodiment
The content of present invention is further illustrated below in conjunction with attached drawing.
Current detection circuit, as shown in Figure 1, including first resistor R1, the first operational amplifier 10, second operational amplifier
20, the first NMOS tube 30, second resistance R2, the first PMOS tube 40, the second PMOS tube 50 and 3rd resistor R3:
The positive input terminal of termination input a Vin and first operational amplifier 10 of the first resistor R1, another termination the
The positive input terminal of two operational amplifiers 20；The positive input of first operational amplifier 10 terminates the one of the first resistor R1
End, negative input terminate the source electrode of first NMOS tube 30 and one end of the second resistance R2, output termination described first
The grid of NMOS tube 30；The positive input of the second operational amplifier 20 terminates one end of the first resistor R1, negative input end
It is connected together with output end and connects one end of the second resistance R2 again；The grid of first NMOS tube 30 connects first operation
The output end of amplifier 10, drain electrode connect the grid of first PMOS tube 40 and the grid of drain electrode and second PMOS tube 50,
Source electrode connects the negative input end of first operational amplifier 10 and one end of the second resistance R2；The one of the second resistance R2
Terminate the negative input end of first operational amplifier 10 and the source electrode of first NMOS tube 30, another termination second fortune
Calculate the negative input end and output end of amplifier 20；The grid of first PMOS tube 40 and drain electrode are connected together connects described first again
The drain electrode of NMOS tube 30 and the grid of second PMOS tube 50, source electrode meet supply voltage VCC；The grid of second PMOS tube 50
Pole connects the drain electrode of first NMOS tube 30 and grid and the drain electrode of first PMOS tube 40, and drain electrode meets the 3rd resistor R3
One end, source electrode meets supply voltage VCC；The drain electrode of termination second PMOS tube 50 of the 3rd resistor R3, the other end
Ground connection.
The voltage at the both ends the first resistor R1 passes through by first operational amplifier 10 and first NMOS tube 30
The follower that the follower of composition and the second operational amplifier 20 are constituted detected, and described second is added in after detected
Electric current I2 is generated on resistance R2, then is flowed out to second PMOS tube 50 in sent third by 40 mirror image of the first PMOS tube
Voltage is generated on resistance R3, the resistance value of the first resistor R1, the second resistance R2 and the 3rd resistor R3 are known
, the voltage VC on the 3rd resistor R3 can be tested out, and counter roll back can be indirectly on the first resistor R1
Testing current come out.
It is only the explanation of the preferred embodiment of the present invention, to this technology to the explanation of above-mentioned provided embodiment
It can be realized or used the present invention from the description above for the technical staff in field.It should be pointed out that being led for this technology
For the technical staff in domain, without departing from the technical principles of the invention, several improvement and deformations can also be made, any
Without departing from the innovation and creation within the scope of true spirit, protection scope of the present invention should be regarded as.
Claims (1)
1. current detection circuit, it is characterised in that: including first resistor R1, the first operational amplifier, second operational amplifier,
First NMOS tube, second resistance R2, the first PMOS tube, the second PMOS tube and 3rd resistor R3；
The positive input terminal of termination input a Vin and first operational amplifier of the first resistor R1, another termination second
The positive input terminal of operational amplifier；The positive input of first operational amplifier terminates one end of the first resistor R1, bears defeated
Enter one end of the source electrode for terminating first NMOS tube and the second resistance R2, output terminates the grid of first NMOS tube
Pole；The positive input of the second operational amplifier terminates one end of the first resistor R1, and negative input end and output terminate at one
Play the one end for meeting the second resistance R2 again；The grid of first NMOS tube connects the output end of first operational amplifier,
Drain electrode connects the grid of first PMOS tube and the grid of drain electrode and second PMOS tube, and source electrode connects first operation amplifier
One end of the negative input end of device and the second resistance R2；Termination first operational amplifier of the second resistance R2
The source electrode of negative input end and first NMOS tube, the negative input end and output end of another termination second operational amplifier；
The grid of first PMOS tube and drain electrode are connected together connects the drain electrode and second PMOS tube of first NMOS tube again
Grid, source electrode meet supply voltage VCC；The grid of second PMOS tube connects the drain electrode and described first of first NMOS tube
The grid of PMOS tube and drain electrode, drain electrode connect one end of the 3rd resistor R3, and source electrode meets supply voltage VCC；The 3rd resistor
The drain electrode of termination second PMOS tube of R3, other end ground connection.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811059752.XA CN109374945A (en) | 2018-09-12 | 2018-09-12 | Current detection circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811059752.XA CN109374945A (en) | 2018-09-12 | 2018-09-12 | Current detection circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN109374945A true CN109374945A (en) | 2019-02-22 |
Family
ID=65405538
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201811059752.XA Pending CN109374945A (en) | 2018-09-12 | 2018-09-12 | Current detection circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109374945A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110045173A (en) * | 2019-05-24 | 2019-07-23 | 杭州科工电子科技有限公司 | A kind of bidirectional current detection circuit |
-
2018
- 2018-09-12 CN CN201811059752.XA patent/CN109374945A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110045173A (en) * | 2019-05-24 | 2019-07-23 | 杭州科工电子科技有限公司 | A kind of bidirectional current detection circuit |
| CN110045173B (en) * | 2019-05-24 | 2024-02-06 | 杭州科工电子科技股份有限公司 | Bidirectional current detection circuit |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| WD01 | Invention patent application deemed withdrawn after publication | ||
| WD01 | Invention patent application deemed withdrawn after publication |
Application publication date: 20190222 |