Novel single-chip platinum resistor signal conditioning circuit and conditioning method
阅读说明：本技术 一种新型的单芯片化铂电阻信号调理电路及调理方法 (Novel single-chip platinum resistor signal conditioning circuit and conditioning method ) 是由 刘敏侠 田泽 刘若曦 邵刚 陈智 吕俊盛 于 2020-12-24 设计创作，主要内容包括：本发明涉及一种新型的单芯片化铂电阻信号调理电路及调理方法。本发明包括输入运放Q1、输入运放Q2、输出运放Q3、PMOS管P1、输出驱动管N1、电流源IR1、电流源IR2、电阻R1、电阻R2和电阻R3,输入运放Q1的输出端和负输入端之间接电阻R1,输入运放Q2的负输入端分别接输入运放Q1的负输入端和PMOS管P1的源端,输入运放Q2的输出端接PMOS管P1的栅极,PMOS管P1的漏端接输出运放Q3的正输入端,输出运放Q3的输出端接输出驱动管N1的基极和输出运放Q3的负输入端,驱动管N1的集电极接电流源IR1、电流源IR2、PMOS管P1的源端和输入运放Q2的负输入端,驱动管N1的发射极接输出运放Q3的负输入端,输出运放Q3的正输入端接电阻R2,负输入端接电阻R3。本发明具有校准精度高,且试用温度范围广的优点。(The invention relates to a novel single-chip platinum resistor signal conditioning circuit and a conditioning method. The invention comprises an input operational amplifier Q1, an input operational amplifier Q2, an output operational amplifier Q3, a PMOS tube P1, an output driving tube N1, a current source IR1, a resistor R1 and a resistor R1, wherein the resistor R1 is connected between the output end and the negative input end of the input operational amplifier Q1, the negative input end of the input operational amplifier Q1 is respectively connected with the negative input end of the input operational amplifier Q1 and the source end of the PMOS tube P1, the output end of the input operational amplifier Q1 is connected with the grid of the PMOS tube P1, the drain end of the PMOS tube P1 is connected with the positive input end of the output operational amplifier Q1, the output end of the output operational amplifier Q1 is connected with the base of the output driving tube N1 and the negative input end of the output operational amplifier Q1, the collector of the driving tube N1 is connected with the current source IR1, the source P1 of the PMOS tube P1, the emitter of the output operational amplifier Q1 is connected with the negative input end of the resistor R1, and the emitter 1. The invention has the advantages of high calibration precision and wide trial temperature range.)
1. A novel single-chip platinum resistance signal conditioning circuit is characterized in that: the conditioning circuit comprises an input operational amplifier Q1, an input operational amplifier Q2, an output operational amplifier Q3, a PMOS tube P1, an output driving tube N1, a current source IR1, a current source IR2, a resistor R2 and a resistor R2, wherein the resistor R2 is connected between the output end and the negative input end of the input operational amplifier Q2, the negative input end of the input operational amplifier Q2 is respectively connected with the negative input end of the input operational amplifier Q2 and the source end of the PMOS tube P2, the output end of the input operational amplifier Q2 is connected with the grid of the PMOS tube P2, the drain end of the PMOS tube P2 is connected with the positive input end of the output operational amplifier Q2, the output end of the output operational amplifier Q2 is connected with the base of the output driving tube N2 and the negative input end of the output operational amplifier Q2, the collector of the driving tube N2 is connected with the current source IR2, the negative input end of the input operational amplifier Q2, the emitter of the output operational amplifier Q2 is connected with the output end of the output operational amplifier Q2, and the emitter of the output operational amplifier Q2, the negative input end is connected with a resistor R3.
2. The novel single-chip platinum resistor signal conditioning circuit of claim 1, wherein: the conditioning circuit further comprises a resistor RGSaid resistance RGIs connected between the negative input terminal of the input operational amplifier Q2 and the negative input terminal of the input operational amplifier Q1.
3. The novel single-chip platinum resistor signal conditioning circuit of claim 2, wherein: the conditioning circuit further comprises a current source I3, and the collector of the driving tube N1 is respectively connected to the source end of the PMOS tube P1 and the negative input end of the input operational amplifier Q2 through the current source I3.
4. The novel single-chip platinum resistor signal conditioning circuit of claim 3, wherein: the conditioning circuit further comprises a resistor R4, and the resistor R4 is connected between the output end of the output operational amplifier Q3 and the base electrode of the output driving tube N1.
5. The novel single-chip platinum resistor signal conditioning circuit of claim 4, wherein: the conditioning circuit further comprises a resistor R5, and the resistor R5 is connected between the emitter and the base of the resistor driving tube N1.
6. The novel single-chip platinum resistor signal conditioning circuit of claim 5, wherein: the conditioning circuit further comprises a resistor R6, and the resistor R6 is connected between the output end and the negative input end of the output operational amplifier Q3.
7. A conditioning method for implementing the novel single-chip platinum resistor signal conditioning circuit of claim 1, wherein: the method comprises the following steps:
1) the high-precision current reference supplies power to the platinum resistor;
2) the voltage flowing through the platinum resistor enters two input operational amplifiers Q1 and Q2;
3) the two input operational amplifiers Q1 and Q2 amplify the differential signals, convert the amplified differential signals into current signals, superpose the current signals with sampling signals of reference current input by a current source I3 through an output operational amplifier Q3, amplify the current signals through two strictly matched precision resistors R2 and R3, and output the current signals of 4-20 mA after amplification.
Technical Field
The invention relates to the field of signal communication of aviation, navigation, industrial control and the like, in particular to a novel single-chip platinum resistor signal conditioning circuit and a conditioning method.
Background
The platinum resistor is a temperature sensor with a very wide application range, and when a resistive sensor signal is transmitted, input drift and nonlinearity greatly affect the characteristics of the sensor, so that the input signal needs to be conditioned and converted into available 4-20 mA for transmission.
Most of existing sensor signal conditioning circuits are voltage output, voltage loss in long-line transmission cannot be avoided, the difference between a signal sampled by a signal processing port after signal attenuation and a sensor source end is large, signal loss can be avoided by adopting a current output mode, a current sending mode can be adopted in long-line transmission, the current of a far end is consistent with the current of the sensor source end, no loss exists, and the anti-interference capability is strong. Therefore, the existing platinum resistance signal conditioning circuit mostly adopts a hardware platinum resistance compensation scheme built by discrete devices and operational amplifiers, and puts forward higher requirements for system engineers, the existing platinum resistance signal conditioning circuit needs to be thoroughly mastered on system performance and is externally connected with a high-precision resistor, the precision of the resistor determines the precision of the final whole system, and the function of linear calibration cannot be carried out; and the hardware system is complex, occupies large volume, and does not accord with the development trend of small, low and light required by the temperature sensor.
Disclosure of Invention
The invention provides a single-chip current output sensor signal conditioning circuit and a conditioning method for solving the technical problems in the background art, and the single-chip current output sensor signal conditioning circuit and the conditioning method adopt the realization mode of a single-chip integrated circuit to integrate precise signal amplification, a current source and a voltage reference in a chip, and calibrate the nonlinearity of a platinum resistor through a closed-loop nonlinear control circuit, so that the calibration precision is high, and the trial temperature range is wide.
The technical solution of the invention is as follows: the invention relates to an intelligent current output sensor signal conditioning circuit, which is characterized in that: the conditioning circuit comprises an input operational amplifier Q1, an input operational amplifier Q2, an output operational amplifier Q3, a PMOS tube P1, an output driving tube N1, a current source IR1, a current source IR2, a resistor R1, a resistor R2 and a resistor R3, the output end and the negative input end of the input operational amplifier Q1 are connected with a resistor R1, the negative input end of the input operational amplifier Q2 is respectively connected with the negative input end of the input operational amplifier Q1 and the source end of a PMOS tube P1, the output end of the input operational amplifier Q2 is connected with the grid electrode of a PMOS tube P1, the drain end of the PMOS tube P1 is connected with the positive input end of the output operational amplifier Q3, the output end of the output operational amplifier Q3 is connected with the base electrode of an output driving tube 737N 6 and the negative input end of an output operational amplifier Q3, the collector electrode of the driving tube N1 is connected with a current source IR1, a current source IR2, the source end of the PMOS tube P1 and the negative input end of the input operational amplifier Q2, the emitter electrode of the driving tube N1 is connected with the negative input end of the output operational amplifier Q3, the positive input end of the output operational. Wherein the current source IR1 and the current source IR2 provide high precision constant current supply for the platinum resistor.
Preferably, the conditioning circuit further comprises a resistor RGResistance RGIs connected between the negative input terminal of the input operational amplifier Q2 and the negative input terminal of the input operational amplifier Q1.
Preferably, the conditioning circuit further comprises a current source I3, and the collector of the driving transistor N1 is connected to the source terminal of the PMOS transistor P1 and the negative input terminal of the input operational amplifier Q2 through the current source I3, respectively.
Preferably, the conditioning circuit further comprises a resistor R4, and the resistor R4 is connected between the output end of the output operational amplifier Q3 and the base of the output driving transistor N1.
Preferably, the conditioning circuit further comprises a resistor R5, and the resistor R5 is connected between the emitter and the base of the resistor driving tube N1.
Preferably, the conditioning circuit further comprises a resistor R6, and the resistor R6 is connected between the output end and the negative input end of the output operational amplifier Q3.
A conditioning method for realizing the novel single-chip platinum resistance signal conditioning circuit is characterized by comprising the following steps: the method comprises the following steps:
1) the high-precision current reference supplies power to the platinum resistor;
2) the voltage flowing through the platinum resistor enters two input operational amplifiers Q1 and Q2;
3) the two input operational amplifiers Q1 and Q2 amplify the differential signals, convert the amplified differential signals into current signals, superpose the current signals with sampling signals of reference current input by a current source I3 through an output operational amplifier Q3, amplify the current signals through two strictly matched precision resistors R2 and R3, and output the current signals of 4-20 mA after amplification.
The platinum resistor is used as a temperature sensor, certain output error and nonlinearity exist, the signal conditioning output circuit of the single-chip platinum resistor temperature sensor processes the nonlinearity of the platinum resistor while amplifying and converting the signal, constant-current power supply is carried out on the platinum resistor, the input end amplifies a small signal and converts the small signal into high-precision controllable current output, the gain is fixed, and the output size is controlled by a nonlinear closed-loop circuit, so the invention has the following advantages: the invention adopts the realization mode of a monolithic integrated circuit, integrates the precise signal amplification, the current source and the voltage reference in a chip, and calibrates the nonlinearity of the platinum resistor through the closed-loop nonlinear control circuit, thereby having high calibration precision and wide trial temperature range.
Drawings
Fig. 1 is a circuit schematic of the present invention.
Detailed Description
The technical solution of the present invention is further described in detail with reference to the accompanying drawings and specific embodiments.
Referring to fig. 1, the structure of the embodiment of the invention includes an input operational amplifier Q1, an input operational amplifier Q2, an output operational amplifier Q3, a PMOS transistor P1, an output driving transistor N1, a current source IR1, a current source IR2, a current source I3, a resistor R1, a resistor R2, a resistor R3, a resistor R4, a resistor R5, a resistor R6, and a resistor R5GA resistor R1 is connected between the output end and the negative input end of the input operational amplifier Q1, the negative input end of the input operational amplifier Q2 is respectively connected with the negative input end of the input operational amplifier Q1 and the source end of a PMOS tube P1, the output end of the input operational amplifier Q2 is connected with the grid electrode of a PMOS tube P1, the drain end of the PMOS tube P1 is connected with the positive input end of the output operational amplifier Q3, the output end of the output operational amplifier Q3 is connected with the base electrode of an output driving tube N1 and the negative input end of an output operational amplifier Q3, the collector electrode of the driving tube N1 is connected with a current source IR1, a current source,The power supply comprises a current source IR2, a source end of a PMOS tube P1 and a negative input end of an input operational amplifier Q2, an emitter of a driving tube N1 is connected with the negative input end of an output operational amplifier Q3, a positive input end of an output operational amplifier Q3 is connected with a resistor R2, the negative input end is connected with a resistor R3, and the resistor R3 is connected with a resistor RGThe output operational amplifier Q1 is connected between the negative input end of the input operational amplifier Q2 and the negative input end of the input operational amplifier Q1, the resistor R4 is connected between the output end of the output operational amplifier Q3 and the base of the output driving tube N1, the resistor R5 is connected between the emitter and the base of the resistor driving tube N1, the resistor R6 is connected between the output end and the negative input end of the output operational amplifier Q3, and the collector of the driving tube N1 is respectively connected to the source end of the PMOS tube P1 and the negative input end of the input operational amplifier Q2 through the current source I3. Wherein the current source IR1 and the current source IR2 provide high precision constant current supply for the platinum resistor.
The invention also provides a conditioning method for realizing the novel single-chip platinum resistance signal conditioning circuit, which comprises the following steps:
1) the high-precision current reference supplies power to the platinum resistor;
2) the voltage VIN + and VIN-flowing through the platinum resistor enters two input operational amplifiers Q1 and Q2;
3) the two input operational amplifiers Q1 and Q2 amplify the differential signals, convert the amplified differential signals into current signals, perform superposition on the current signals and sampling signals of reference current input by a current source I3 through an output operational amplifier Q3, amplify the current signals through two strictly matched precision resistors R2 and R3, and output 4-20 mA current signals IO。
The transfer function of the platinum resistor after amplification and voltage-current conversion through a complete operational amplifier is as follows:
I0＝4mmA+VIN·(40/RG)
VINthe value of (A) is caused by the variation of resistance value after the platinum resistor senses the temperature, wherein RGThe resistance value of the connected resistor is selected by the characteristics and the working temperature range of the platinum resistor.
Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.
- 上一篇：一种医用注射器针头装配设备
- 下一篇：一种温度检测电路、温度检测方法及电动工具