CN201936215U - Novel high-precision constant current source circuit - Google Patents
Novel high-precision constant current source circuit Download PDFInfo
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- CN201936215U CN201936215U CN2011200619738U CN201120061973U CN201936215U CN 201936215 U CN201936215 U CN 201936215U CN 2011200619738 U CN2011200619738 U CN 2011200619738U CN 201120061973 U CN201120061973 U CN 201120061973U CN 201936215 U CN201936215 U CN 201936215U
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Abstract
The utility model relates to a novel high-precision constant current source circuit, which comprises a reference power supply, a compound amplifier A1, a follower amplifier A2 and a floating power supply, wherein the inverted input end of the compound amplifier A1 is connected with the anode of the reference power supply; the output end of the compound amplifier A1 is connected with the cathode of the reference power supply; the forward input end of the compound amplifier A1 is connected with the forward input end of the follower amplifier A2; the floating power supply supplies power to the compound amplifier A1; the compound amplifier A1 is formed by connecting a main amplifier, a pair of field-effect transistors and a chopping amplifier; the input end of the main amplifier is connected with the pair of field-effect transistors with completely-same performances; and the main amplifier is connected with the chopping amplifier. The novel high-precision constant current source circuit has a reasonable design and meets the requirement for design resolution (the design resolution reaches 0.1 nanoamp level); and the novel high-precision constant current source circuit has the characteristics of high precision, stable performance, low cost and the like and can be widely applied to various fields requiring precise measurement.
Description
Technical field
The utility model belongs to the constant current source field, especially a kind of novel high-accuracy constant-current source circuit.
Background technology
At present, constant current source has in various electronic measurement circuit and sensor electronics very widely to be used, and is irreplaceable unit in the occasions such as LED new forms of energy, input and power amplification.High precise current source is widely used in intelligence instrument and the advanced detection technique especially.Because the high precise current source output current is little, precision is high, therefore, high precise current source is compared easier be subjected to ripple and The noise in the circuit with general constant-current source circuit, make it be difficult to bring up to 0.1 resolution of receiving the peace level, can not satisfy the needs of high-acruracy survey.
Summary of the invention
The purpose of this utility model is to overcome the deficiencies in the prior art, provides a kind of reasonable in design and can make resolution reach the 0.1 novel high-accuracy constant-current source circuit of receiving peace level.
The utility model solves its technical matters and takes following technical scheme to realize:
A kind of novel high-accuracy constant-current source circuit; comprise reference power source; composite amplifier A1; the follower amplifier A2 and the power supply of floating; the inverting input of this composite amplifier A1 and the positive pole of reference power source; one end of resistance R 1 is connected; the output terminal of composite amplifier A1 and the negative pole of reference power source; one end of the other end of resistance R 1 and resistance R 3 is connected; the positive input of composite amplifier A1 is connected with the positive input of follower amplifier A2 and an end of resistance R 2; the inverting input of follower amplifier A2 is connected with the ground B end of floating of the output terminal and the power supply of floating; two power output ends of power supply floated are connected with the power input of composite amplifier A1 respectively; the B end is connected with the input protection shielding end of composite amplifier A1 with floating floating of power supply; the other end of the other end of resistance R 2 and resistance R 3 is connected with ground wire by load jointly; described composite amplifier A1 is by main amplifier; a pair of field effect transistor and chopper amplifier connect and compose; input end at main amplifier connects the duplicate field effect transistor of a pair of performance, and main amplifier is connected with chopper amplifier.
And described main amplifier is a precision amplifier, and described chopper amplifier uses the chopper amplifier of high input impedance and low input offset voltage.
And described resistance R 1, resistance R 2 and resistance R 3 are used accurate wire-wound resistor.
Advantage of the present utility model and good effect are:
The utility model is with the high precision composite amplifier, the follower amplifier and the power supply of floating organically link together, thereby reduce environment temperature to the full extent, humidity, the error that voltage fluctuation and device self drift etc. produces, satisfied the requirement of the design resolution (resolution reach 0.1 receive peace level) of high-accuracy constant-current source circuit, improved the cost performance of the antijamming capability and the circuit of testing circuit, simultaneously, the high precision composite amplifier adopts main amplifier, a pair of FET field effect transistor and chopper amplifier are formed, it is low to have cost, characteristics such as stable performance can be widely used in the every field that needs precision measurement.
Description of drawings
Fig. 1 is a circuit block diagram of the present utility model;
Fig. 2 is a circuit diagram of the present utility model.
Embodiment
Below in conjunction with accompanying drawing the utility model embodiment is further described:
A kind of novel high-accuracy constant-current source circuit, as shown in Figure 1, comprise reference power source Vref, composite amplifier A1, follower amplifier A2, float power supply and resistance R 1, R2, R3, in order to guarantee the precision of constant-current source circuit, described resistance R 1, R2, R3 select the extraordinary accurate wire-wound resistor of stability for use, and its temperature coefficient is better than the 2PPM/ degree.The annexation of this constant-current source circuit is: the positive pole of the inverting input of composite amplifier A1 and reference power source Vref; the end of accurate wire-wound resistor R1 is connected; the negative pole of the output terminal of composite amplifier A1 and reference power source Vref; the other end of accurate wire-wound resistor R1 and the end of accurate wire-wound resistor R3 are connected; the positive input of composite amplifier A1 is connected with the positive input of follower amplifier A2 and the end of accurate wire-wound resistor R2; the inverting input of follower amplifier A2 and the output terminal of follower amplifier A2 and the power supply of floating the ground B end of floating be connected; two power output end+B of power supply float;-B is connected with the power input of composite amplifier A1 respectively; float power supply the ground B end of floating hold B to be connected with the input protection shielding of composite amplifier A1, the other end of the other end of accurate wire-wound resistor R2 and accurate wire-wound resistor R3 is connected with ground wire by load jointly.The principle of work of this constant-current source circuit is: float power supply and follower amplifier A2 are composite amplifier A1 power supply, and composite amplifier A1 is as an ideal amplifier, and when a reference power source Vref was added on the resistance R 1, its electric current was I
R1=Vref/R1, owing to do not have electric current to flow through (input impedance of amplifier is for infinitely great) on the resistance R 2, so V
R3=Vref flows through the electric current I of load
Z=V
R3/ R3=Vref/R3, this electric current all flows through load, and the size of this electric current only depends on Vref and R3, is not subjected to the influence of load size.
Be that example specifies the utility model with circuit shown in Figure 2 below.
The composite amplifier of this constant-current source circuit is formed a high-gain composite amplifier jointly by main amplifier N2, a pair of field effect transistor (V5, V6) and chopper amplifier N3, main amplifier N2 is a precision amplifier, input end at main amplifier N2 connects the duplicate FET field effect transistor of a pair of performance (V5, V6), their grid is as the input end of main amplifier N2, so just improved the input impedance of main amplifier N2 greatly, its value is 10
12Ohm.Use chopper amplifier N3 to cooperate main amplifier N2 to carry out stable output simultaneously, chopper amplifier N3 is as a kind of high precision chopper amplifier, and its input impedance is 10
12Ohm, and its input offset voltage is very low has only 1 microvolt, such design has made full use of the low maladjustment voltage of N3, the characteristics of high stable, be combined into a good linearity, good stability, offset voltage very little again be bordering on desirable amplifier.That is to say, because the offset voltage of N3 is very little, about 1 microvolt, by its regulating action, make that the imbalance of N2 is adjusted, its numerical value also is about 1 microvolt, and promptly the offset voltage of whole amplifier also is about 1 microvolt, the offset voltage of whole amplifier is little, so just can be all the more stable when work.
In order to prevent that faint leakage between chopper amplifier N3 pin from causing the influence to constant-current source circuit; by stabilivolt V1; V2 and triode V3; V4 and resistance R 1; R2; R3; R4; the power supply of floating that R5 forms is the composite amplifier power supply; power output end+the B of this power supply of floating;-B is connected amplifier N2; the power input of N3 is its power supply; the reference point of follower amplifier N1 (positive input of amplifier N1) is from the input end H of the field effect transistor of composite amplifier; the inverting input of this follower amplifier N1 is connected with the output terminal of follower amplifier N1; float power supply be connected with the input protection of chopper amplifier N3 shielding end B with floating; make that like this input end and the protection mask end of chopper amplifier N3 are idiostatic; further avoid forward and reverse leakage of electric current, be not subjected to the influence of other factors with the electric current that guarantees to flow through load.
Resistance R 15 among Fig. 2, R16, R17 select the extraordinary accurate wire-wound resistor of stability for use equally corresponding to the resistance R among Fig. 11, R3, R2, and its temperature coefficient is better than the 2PPM/ degree, so just can guarantee the highly stable output of amplifier.
It is emphasized that; embodiment described in the utility model is illustrative; rather than it is determinate; therefore the utility model is not limited to the embodiment described in the embodiment; every by those skilled in the art according to other embodiments that the technical solution of the utility model draws, belong to the scope of the utility model protection equally.
Claims (3)
1. novel high-accuracy constant-current source circuit; it is characterized in that: comprise reference power source; composite amplifier A1; the follower amplifier A2 and the power supply of floating; the inverting input of this composite amplifier A1 and the positive pole of reference power source; one end of resistance R 1 is connected; the output terminal of composite amplifier A1 and the negative pole of reference power source; one end of the other end of resistance R 1 and resistance R 3 is connected; the positive input of composite amplifier A1 is connected with the positive input of follower amplifier A2 and an end of resistance R 2; the inverting input of follower amplifier A2 is connected with the ground B end of floating of the output terminal and the power supply of floating; two power output ends of power supply floated are connected with the power input of composite amplifier A1 respectively; the B end is connected with the input protection shielding end of composite amplifier A1 with floating floating of power supply; the other end of the other end of resistance R 2 and resistance R 3 is connected with ground wire by load jointly; described composite amplifier A1 is by main amplifier; a pair of field effect transistor and chopper amplifier connect and compose; input end at main amplifier connects the duplicate field effect transistor of a pair of performance, and main amplifier is connected with chopper amplifier.
2. novel high-accuracy constant-current source circuit according to claim 1 is characterized in that: described main amplifier is a precision amplifier, and described chopper amplifier uses the chopper amplifier of high input impedance and low input offset voltage.
3. novel high-accuracy constant-current source circuit according to claim 1 and 2 is characterized in that: described resistance R 1, resistance R 2 and resistance R 3 are used accurate wire-wound resistor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011200619738U CN201936215U (en) | 2011-03-11 | 2011-03-11 | Novel high-precision constant current source circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011200619738U CN201936215U (en) | 2011-03-11 | 2011-03-11 | Novel high-precision constant current source circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN201936215U true CN201936215U (en) | 2011-08-17 |
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ID=44447732
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2011200619738U Expired - Fee Related CN201936215U (en) | 2011-03-11 | 2011-03-11 | Novel high-precision constant current source circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN201936215U (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106324303A (en) * | 2016-11-16 | 2017-01-11 | 天津市盛丹电子技术发展有限公司 | Multi-scale precise constant flow source circuit |
| CN106406407A (en) * | 2016-11-16 | 2017-02-15 | 天津市盛丹电子技术发展有限公司 | Multi-range high-accuracy constant current source |
| CN106444952A (en) * | 2016-11-16 | 2017-02-22 | 天津市盛丹电子技术发展有限公司 | High voltage constant current source |
-
2011
- 2011-03-11 CN CN2011200619738U patent/CN201936215U/en not_active Expired - Fee Related
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106324303A (en) * | 2016-11-16 | 2017-01-11 | 天津市盛丹电子技术发展有限公司 | Multi-scale precise constant flow source circuit |
| CN106406407A (en) * | 2016-11-16 | 2017-02-15 | 天津市盛丹电子技术发展有限公司 | Multi-range high-accuracy constant current source |
| CN106444952A (en) * | 2016-11-16 | 2017-02-22 | 天津市盛丹电子技术发展有限公司 | High voltage constant current source |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20110817 Termination date: 20140311 |