CN208299764U - A kind of current amplification circuit - Google Patents
A kind of current amplification circuit Download PDFInfo
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- CN208299764U CN208299764U CN201820993502.2U CN201820993502U CN208299764U CN 208299764 U CN208299764 U CN 208299764U CN 201820993502 U CN201820993502 U CN 201820993502U CN 208299764 U CN208299764 U CN 208299764U
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Abstract
The utility model discloses a kind of current amplification circuits, it include: an operational amplifier, the reverse input end of the operational amplifier connects a reference voltage, the non-inverting input terminal of the operational amplifier connects current detection voltage by a resistance, the grid of the metal-oxide-semiconductor and a pwm signal, the drain electrode of the metal-oxide-semiconductor connects a current signal, the base stage of first NPN triode connects supply voltage, the base stage of first NPN triode connects the output end of the comparator, the circuit structure of the utility model is fairly simple, cost of manufacture is relatively low, increase by the triode of two NPN on the basis of existing circuit, bipolar amplification makes a diode anode voltage within the 1us time by 5mV voltage amplification to VCC voltage, it is big to aim at solution tiny signal transmitting difficulty, a kind of Current amplifier at high cost Circuit realizes that Weak current is detected using two-stage amplification using common comparator, promotion and popularization value with higher.
Description
Technical field
The utility model relates to amplify Weak current application circuit more particularly to a kind of current amplification circuit.
Background technique
General amplification tiny signal needs use high-precision, high speed, the big operational amplifier of slew rate, this class A amplifier A valence
Lattice are high, and are affected by temperature larger.The tiny signal of 5mV is amplified to VCC voltage within the 1us time, if with high-precision,
The operational amplifier of high speed and high pressure Slew Rate, price is very high, defeated if simple reduction R29 resistance value if exported with comparator
Output capacity is inadequate, and VCC is not achieved in 4 foot voltages.
Utility model content
The purpose of this utility model is that solve the above-mentioned problems and provides a kind of current amplification circuit.
The utility model is achieved through the following technical solutions above-mentioned purpose.
A kind of current amplification circuit includes:
The reverse input end of one operational amplifier, the operational amplifier connects a reference voltage；The operational amplifier
Non-inverting input terminal by a resistance connect current detection voltage；
One metal-oxide-semiconductor, the grid of the metal-oxide-semiconductor and a pwm signal；The drain electrode of the metal-oxide-semiconductor connects a current signal；It is described
The source electrode of metal-oxide-semiconductor connects ground terminal by a resistance；
The base stage of one first NPN triode, first NPN triode connects supply voltage, first NPN triode
Base stage connect the output end of the comparator, the emitter of first NPN triode connects the base of one second NPN triode
Pole, the emitter of second NPN triode connect a diode with the base stage of first NPN triode.
Preferably, the base stage of first NPN triode passes through the 29th resistance and the 5th of the operational amplifier the
Output end connection.
Preferably, further include the 7th capacitor, the 7th capacitor one end connect with the first input end of the comparator,
The other end of 7th capacitor is connect with ground terminal.
It preferably, further include the 9th capacitor, one end of the 9th capacitor and the emitter of second NPN triode connect
It connects, the other end connects ground terminal.
It preferably, further include the 8th capacitor, described 8th capacitor one end is connected to described by one the 23rd resistance
The emitter of two NPN triodes, the other end are connect with ground terminal.
Preferably, the minimum current for flowing through the metal-oxide-semiconductor is 0.5A, maximum current 20A.
Preferably, the signal of the PWM output is the 1KHZ square-wave signal of 0.1-100%.
Utility model has the advantages that
The circuit structure of the utility model is fairly simple, and cost of manufacture is relatively low, increases by two on the basis of existing circuit
The triode of NPN, it is bipolar amplification make a diode anode voltage within the 1us time by 5mV voltage amplification to VCC voltage, have
Higher promotion and popularization value, aims at and solves a kind of big, the at high cost current amplification circuit of tiny signal transmitting difficulty, and use is general
Logical comparator realizes that Weak current is detected using two-stage amplification.
Detailed description of the invention
If Fig. 1 is a kind of schematic diagram of current amplification circuit preferred embodiment of the utility model.
Specific embodiment
The following will be combined with the drawings in the embodiments of the present invention, carries out the technical scheme in the embodiment of the utility model
Clearly and completely describe, it is clear that the described embodiments are only a part of the embodiments of the utility model, rather than whole
Embodiment.Based on the embodiments of the present invention, those of ordinary skill in the art are in the premise for not making creative work
Under every other embodiment obtained, fall within the protection scope of the utility model.
It should be noted that in the absence of conflict, the feature in the embodiments of the present invention and embodiment can
To be combined with each other.
The utility model is described in further detail in the following with reference to the drawings and specific embodiments, but not as the utility model
It limits.
As shown in Figure 1, in the utility model preferred embodiment, according to problem of the existing technology, the utility model
A kind of current amplification circuit is provided, includes:
The reverse input end of one operational amplifier, operational amplifier connects a reference voltage；Operational amplifier it is same mutually defeated
Enter end and current detection voltage is connected by a resistance；
One metal-oxide-semiconductor, the grid of metal-oxide-semiconductor and a pwm signal；The drain electrode of metal-oxide-semiconductor connects a current signal；The source electrode of metal-oxide-semiconductor
Ground terminal is connected by a resistance；
One first NPN triode, the base stage of the first NPN triode connect supply voltage, and the base stage of the first NPN triode connects
The output end of comparator is connect, the emitter of the first NPN triode connects the base stage of one second NPN triode, the second NPN triode
Emitter connect a diode with the base stage of the first NPN triode.
In the utility model preferred embodiment, the base stage of the first NPN triode is put by the 29th resistance with operation
The 5th output end connection of big device.
It further include the 7th capacitor in the utility model preferred embodiment, the first of one end of the 7th capacitor and comparator
Input terminal connection, the other end of the 7th capacitor are connect with ground terminal.
It further include the 9th capacitor, one end of the 9th capacitor and the second NPN triode in the utility model preferred embodiment
Emitter connection, the other end connect ground terminal.
It further include the 8th capacitor in the utility model preferred embodiment, the 8th capacitor one end passes through one the 23rd electricity
Resistance is connected to the emitter of the second NPN triode, and the other end is connect with ground terminal.
In the utility model preferred embodiment, the minimum current for flowing through metal-oxide-semiconductor is 0.5A, maximum current 20A.
In the utility model preferred embodiment, the signal of PWM output is the 1KHZ square-wave signal of 0.1-100%.
Working principle of the utility model is: as shown in Figure 1, the signal that PWM is provided is the 1KHZ square wave letter of 0.1-100%
Number, It is the electric current for flowing through metal-oxide-semiconductor, and minimum current 0.5A, maximum current 20A are 0.1% when electric current is 0.5A duty ratio
When, 1 foot voltage of comparator is 5mV, turn-on time 1us, so the tiny signal of 5mV is amplified to VCC within the 1us time
Voltage, if at a high speed with the operational amplifier of high pressure Slew Rate, price is very high, if exported with comparator, subtracts merely with high-precision
The resistance value of few 29th resistance R29, fan-out capability is inadequate, and VCC is not achieved in 4 foot voltages.This patent increases by two on this basis
The triode of a NPN, bipolar amplification make a diode D4 anode voltage within the 1us time by 5mV voltage amplification to VCC voltage,
To reduce cost.
The utility model has the beneficial effects that:
The circuit structure of the utility model is fairly simple, and cost of manufacture is relatively low, increases by two on the basis of existing circuit
The triode of NPN, it is bipolar amplification make a diode anode voltage within the 1us time by 5mV voltage amplification to VCC voltage, have
Higher promotion and popularization value, aims at and solves a kind of big, the at high cost current amplification circuit of tiny signal transmitting difficulty, and use is general
Logical comparator realizes that Weak current is detected using two-stage amplification.
The foregoing is merely the utility model preferred embodiment, be not intended to limit the embodiments of the present invention and
Protection scope should can appreciate that all in the utility model specification and diagram to those skilled in the art
Hold made equivalent replacement and obviously change obtained scheme, the protection model of the utility model should all be included in
In enclosing.
Claims (7)
1. a kind of current amplification circuit characterized by comprising
The reverse input end of one operational amplifier, the operational amplifier connects a reference voltage；The operational amplifier it is same
Phase input terminal connects current detection voltage by a resistance；
One metal-oxide-semiconductor, the grid of the metal-oxide-semiconductor and a pwm signal；The drain electrode of the metal-oxide-semiconductor connects a current signal；The MOS
The source electrode of pipe connects ground terminal by a resistance；
The base stage of one first NPN triode, first NPN triode connects supply voltage, the base of first NPN triode
Pole connects the output end of the comparator, and the emitter of first NPN triode connects the base stage of one second NPN triode,
The emitter of second NPN triode connect a diode with the base stage of first NPN triode.
2. a kind of current amplification circuit according to claim 1, which is characterized in that the base stage of first NPN triode
It is connect by the 29th resistance with the 5th output end of the operational amplifier.
3. a kind of current amplification circuit according to claim 1, which is characterized in that further include the 7th capacitor, the described 7th
One end of capacitor is connect with the first input end of the comparator, and the other end of the 7th capacitor is connect with ground terminal.
4. a kind of current amplification circuit according to claim 1, which is characterized in that it further include the 9th capacitor, the described 9th
One end of capacitor is connect with the emitter of second NPN triode, and the other end connects ground terminal.
5. a kind of current amplification circuit according to claim 1, which is characterized in that it further include the 8th capacitor, the described 8th
Capacitor one end is connected to the emitter of second NPN triode by one the 23rd resistance, and the other end is connect with ground terminal.
6. a kind of current amplification circuit according to claim 1, which is characterized in that flow through the minimum current of the metal-oxide-semiconductor
For 0.5A, maximum current 20A.
7. a kind of current amplification circuit according to claim 1, which is characterized in that the signal of the PWM output is 0.1-
100% 1KHZ square-wave signal.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201820993502.2U CN208299764U (en) | 2018-06-26 | 2018-06-26 | A kind of current amplification circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201820993502.2U CN208299764U (en) | 2018-06-26 | 2018-06-26 | A kind of current amplification circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN208299764U true CN208299764U (en) | 2018-12-28 |
Family
ID=64701145
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201820993502.2U Active CN208299764U (en) | 2018-06-26 | 2018-06-26 | A kind of current amplification circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN208299764U (en) |
-
2018
- 2018-06-26 CN CN201820993502.2U patent/CN208299764U/en active Active
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|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| CP03 | Change of name, title or address | ||
| CP03 | Change of name, title or address |
Address after: No. 122315000 Jianlan Road, Gaoxin District, Ningbo, Zhejiang Patentee after: Ningbo sainaibi Photoelectric Technology Co.,Ltd. Address before: No.56 Keda Road, hi tech Zone, Ningbo City, Zhejiang Province, 315000 Patentee before: NINGBO SNAPPY OPTOELECTRONICS Co.,Ltd. |