阅读说明：本技术 一种智能化电流传感器信号的调理方法及其调理电路 (Intelligent current sensor signal conditioning method and conditioning circuit thereof ) 是由 胡曙凡 田泽 刘敏侠 权炜 邵刚 刘若曦 余立宁 于 2020-12-24 设计创作，主要内容包括：本发明涉及一种智能化电流传感器信号的调理方法及其调理电路。本发明的方法包括以下步骤：1)确定测温范围,选择合适的通路和对应参考电阻的值；2)计算信号调理的数据,写入电路配置寄存器；3)利用写入电路配置寄存器的值对内部DAC以及运算放大器参数进行调整,以改变激励电流、零点电流等参数,完成信号调理。本发明具有对铂电阻信号调理范围大、输出电流线性化调整比率大且占用空间小的优点。(The invention relates to an intelligent current sensor signal conditioning method and a conditioning circuit thereof. The method of the invention comprises the following steps: 1) determining a temperature measuring range, and selecting a proper path and a value of a corresponding reference resistor; 2) calculating data conditioned by the signal, and writing the data into a circuit configuration register; 3) and adjusting parameters of an internal DAC and an operational amplifier by using the value written into the circuit configuration register so as to change parameters such as excitation current, zero current and the like and finish signal conditioning. The invention has the advantages of large platinum resistance signal conditioning range, large output current linearization adjustment ratio and small occupied space.)

1. An intelligent current sensor signal conditioning method is characterized in that: the method comprises the following steps:

1) determining a temperature measuring range, and selecting a proper path and a value of a corresponding reference resistor;

2) calculating data conditioned by the signal, and writing the data into a circuit configuration register;

3) and adjusting parameters of an internal DAC and an operational amplifier by using the value written into the circuit configuration register so as to change parameters such as excitation current, zero current and the like and finish signal conditioning.

2. The method for conditioning a signal of an intelligent current sensor according to claim 1, characterized in that: the data of signal conditioning in the step 2) comprise the gain of the operational amplifier, the current flowing through the platinum resistor and the magnitude of the internal adjusting current.

3. The method for conditioning a signal of an intelligent current sensor according to claim 2, characterized in that: and the data conditioned by the signal in the step 2) is written into a circuit configuration register by using a host or an EEPROM through an SPI interface.

4. The method for conditioning a signal of an intelligent current sensor according to claim 3, characterized in that: the internal DAC in the step 3) comprises a current linearization adjustment DAC and a zero point adjustment DAC.

5. A conditioning circuit for implementing the method of conditioning an intelligent current sensor signal of claim 1, characterized in that: this circuit includes operational amplifier, electric current linearity adjustment DAC, zero point adjustment DAC, SPI interface, EEPROM, host computer and circuit configuration register, host computer and EEPROM are connected with circuit configuration register through the SPI interface respectively, circuit configuration register is connected with operational amplifier, electric current linearity adjustment DAC and zero point adjustment DAC respectively, wherein: the operational amplifier, the current linear adjustment DAC and the zero adjustment DAC are used for signal conditioning; the SPI interface, the EEPROM and the host are used for configuring control values of the circuit configuration register.

Technical Field

The invention relates to the fields of aviation, navigation, industrial control and the like, in particular to an intelligent current sensor signal conditioning method and a conditioning circuit thereof.

Background

The platinum thermal resistor is a widely used temperature sensor, which has the characteristics of small volume, high accuracy, wide temperature measuring range, good stability, positive temperature coefficient and the like, but has the defect of nonlinearity, so when the platinum thermal resistor is used for carrying out accurate temperature measurement, the nonlinearity of the platinum thermal resistor needs to be corrected in addition to overcoming the noise interference of a measuring circuit. The existing correction mode adopts software to compensate the nonlinear error of the platinum resistor or adopts hardware to directly condition signals. These approaches exist with a small range of platinum resistance signal conditioning; the output current linearization adjustment ratio is smaller; the signal conditioning using discrete devices has the disadvantage of larger occupied space of peripheral circuits.

Disclosure of Invention

The invention provides an intelligent current sensor signal conditioning method and a conditioning circuit thereof for solving the technical problems in the background art, and the method has the advantages of full digitalization of platinum resistance signal correction, intelligent output current linear adjustment and small occupied space.

The solution of the invention is: the invention relates to an intelligent current sensor signal conditioning method, which is characterized in that: the method comprises the following steps:

1) determining a temperature measuring range, and selecting a proper path and a value of a corresponding reference resistor;

2) calculating data conditioned by the signal, and writing the data into a circuit configuration register;

3) and adjusting parameters of an internal DAC and an operational amplifier by using the value written into the circuit configuration register so as to change parameters such as excitation current, zero current and the like and finish signal conditioning.

The data of signal conditioning in step 2) includes the gain of the operational amplifier, the current flowing through the platinum resistor and the internal adjusting current.

And 2) writing the signal conditioning data in the step 2) into a circuit configuration register by using a host or an EEPROM through an SPI interface.

And 3) the internal DAC comprises a current linearization adjustment DAC and a zero point adjustment DAC.

A conditioning circuit for realizing the intelligent current sensor signal conditioning method is characterized in that: this circuit includes operational amplifier, electric current linearity adjustment DAC, zero point adjustment DAC, SPI interface, EEPROM, host computer and circuit configuration register, and host computer and EEPROM are connected with circuit configuration register through the SPI interface respectively, and circuit configuration register is connected with operational amplifier, electric current linearity adjustment DAC and zero point adjustment DAC respectively, wherein: the operational amplifier, the current linear adjustment DAC and the zero adjustment DAC are used for signal conditioning; the SPI interface, the EEPROM and the host are used for configuring control values of the circuit configuration register.

The invention provides an intelligent current sensor signal conditioning method and a conditioning circuit thereof, which comprises the steps of firstly calculating the gain of an operational amplifier, the current flowing through a platinum resistor and the magnitude of internal adjustment current, writing a configuration value generated by calculation into a circuit configuration register through an SPI (serial peripheral interface) interface by using a host or an EEPROM (electrically erasable programmable read-only memory), changing the circuit configuration, and calibrating the range, zero offset, nonlinear coefficient and the like of an analog signal (sensor data) path by adjusting the parameters of the operational amplifier, a current linear adjustment DAC and a zero adjustment DAC to achieve the aim of nonlinear reduction of a sensor signal. And the chip is internally provided with a digital communication interface compatible with a standard SPI serial bus, and allows a user to carry out full digital calibration on zero offset, a measuring range, a nonlinear coefficient of a sensor and the like of an analog signal path through the SPI, and an external potentiometer and manual fine adjustment are not needed, so that the invention has the advantages of full digital platinum resistance signal calibration, intelligent output current linear adjustment and small occupied space.

Drawings

FIG. 1 is a flow chart of a method of the present invention;

fig. 2 is a circuit block diagram 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 method of an embodiment of the present invention comprises the steps of:

1) determining a temperature measuring range, and selecting a proper path and a value of a corresponding reference resistor;

2) calculating data conditioned by the signal, and writing the data into a circuit configuration register; the signal conditioning data includes the gain of the operational amplifier, the current through the platinum resistor and the magnitude of the internal conditioning current; the data of signal conditioning is written into a circuit configuration register through an SPI interface by utilizing a host or an EEPROM;

3) adjusting parameters of an internal DAC and an operational amplifier by using the value written into the circuit configuration register so as to change parameters such as excitation current, zero current and the like and finish signal conditioning; the internal DAC includes a current linearization adjustment DAC and a zero point adjustment DAC.

Referring to fig. 2, the structure of the embodiment of the present invention includes an operational amplifier, a current linearity adjusting DAC, a zero point adjusting DAC, an SPI interface, an EEPROM, a host, and a circuit configuration register, where the host and the EEPROM are respectively connected to the circuit configuration register through the SPI interface, and the circuit configuration register is respectively connected to the operational amplifier, the current linearity adjusting DAC, and the zero point adjusting DAC, where: the operational amplifier, the current linear adjustment DAC and the zero adjustment DAC are used for signal conditioning; the SPI interface, the EEPROM and the host are used for configuring control values of the circuit configuration register.

The working principle is as follows: the gain of the operational amplifier is calculated, the current flowing through the platinum resistor and the internal adjusting current are calculated, the configuration value generated by calculation is written into a circuit configuration register through an SPI (serial peripheral interface) by using a host or an EEPROM (electrically erasable programmable read-only memory), the circuit configuration is changed, and the measuring range, the zero offset, the amplification factor and the like of an analog signal (sensor data) path are calibrated by adjusting the parameters of the operational amplifier, the current linear adjusting DAC and the zero adjusting DAC, so that the aim of nonlinear reduction of the sensor signal is fulfilled.

The noun explains:

DAC: a digital-to-analog converter.

An EEPROM: the electrified erasable programmable read only memory.

SPI interface: a serial peripheral interface.

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.