Chemical/gas sensor solutions
Update time：2020-04-01 Pageviews：691
Electrochemical sensors are widely used as sensing mechanisms for gas and chemical sensing. Common applications include carbon monoxide detectors, chemical species identification, current analysis sensors, etc. An electrochemical sensor can be simply regarded as a sensor that converts the physical characteristics of the gas/chemical concentration into an electrical signal that can be processed by an instrument.
Signal conditioning:
Programmable analog front end (AFE) is especially suitable for micro-power electrochemical sensing applications. It can provide a complete signal path solution between the sensor and the microcontroller, and can generate an output voltage proportional to the battery current. Programmability enables it to support multiple electrochemical sensors (for example, three-electrode toxic gas sensors and two-electrode galvanic sensors) through one design, without the need for multiple separate solutions. AFE supports gas sensitivity ranging from 0.5 nA/ppm to 9500 nA/ppm. It also allows simple conversion of the full current range from 5µA to 750µA. Adjustable battery deviation and transimpedance amplifier (TIA) gain can be programmed through the I2C interface. The I2C interface can also be used for sensor diagnosis. The integrated temperature sensor can be read by the user through the VOUT pin, and can be used to provide additional signal correction (unit: µC), or be monitored to verify the temperature of the sensor. The AFE is optimized for micro-power applications and operates in a voltage range of 2.7V to 5.25V. The total current consumption can be less than 10μA. More power consumption can be saved by turning off the TIA amplifier and using an internal switch to shorten the distance from the reference electrode to the working electrode.
Signal acquisition and processing:
TI's high-resolution differential ADCs have low power consumption, wide dynamic range and low noise. It can be used to digitize the adjusted analog bridge output to achieve high resolution and accurate measurement. In addition, TI's MSP430 microcontroller with integrated ADC and DAC can also be used. The following post-processing algorithms can be run on this MCU.
Interface and communication:
The traditional analog (4-20mA) interface is still a common choice for industrial control and sensor applications. Other common protocols include HART, Profibus and IO-Link. TI's IO-Link interface products integrate voltage regulators and diagnostic outputs. In addition, wireless options based on the IEEE 802.15.4 protocol are becoming more and more popular. TI is committed to providing solutions for both traditional and emerging industrial interfaces.
Power management
The field transmitter can use three power supply modes. Line-powered transmitters are usually powered by a 12V or 24V voltage rail. The loop-powered transmitter is powered by a 4-20mA loop. This type of transmitter requires a very low-power architecture because the entire solution must be powered by the loop. TI provides high-efficiency step-down converters with low quiescent current and low output ripple, suitable for line-powered and loop-powered transmitters. Battery-powered transmitters can be powered by TI's low-power buck converter and buck/boost converter designs. The DC/DC step-down converter can provide more than 95% efficiency over a large battery voltage range, while the input voltage can even be reduced to 1.8V, thereby extending battery life. A dedicated buck/boost converter can generate the required stable output voltage, can provide a constant current when the input voltage is too high or too low, and support a variety of battery configurations.
Signal conditioning:
Programmable analog front end (AFE) is especially suitable for micro-power electrochemical sensing applications. It can provide a complete signal path solution between the sensor and the microcontroller, and can generate an output voltage proportional to the battery current. Programmability enables it to support multiple electrochemical sensors (for example, three-electrode toxic gas sensors and two-electrode galvanic sensors) through one design, without the need for multiple separate solutions. AFE supports gas sensitivity ranging from 0.5 nA/ppm to 9500 nA/ppm. It also allows simple conversion of the full current range from 5µA to 750µA. Adjustable battery deviation and transimpedance amplifier (TIA) gain can be programmed through the I2C interface. The I2C interface can also be used for sensor diagnosis. The integrated temperature sensor can be read by the user through the VOUT pin, and can be used to provide additional signal correction (unit: µC), or be monitored to verify the temperature of the sensor. The AFE is optimized for micro-power applications and operates in a voltage range of 2.7V to 5.25V. The total current consumption can be less than 10μA. More power consumption can be saved by turning off the TIA amplifier and using an internal switch to shorten the distance from the reference electrode to the working electrode.
Signal acquisition and processing:
TI's high-resolution differential ADCs have low power consumption, wide dynamic range and low noise. It can be used to digitize the adjusted analog bridge output to achieve high resolution and accurate measurement. In addition, TI's MSP430 microcontroller with integrated ADC and DAC can also be used. The following post-processing algorithms can be run on this MCU.
Interface and communication:
The traditional analog (4-20mA) interface is still a common choice for industrial control and sensor applications. Other common protocols include HART, Profibus and IO-Link. TI's IO-Link interface products integrate voltage regulators and diagnostic outputs. In addition, wireless options based on the IEEE 802.15.4 protocol are becoming more and more popular. TI is committed to providing solutions for both traditional and emerging industrial interfaces.
Power management
The field transmitter can use three power supply modes. Line-powered transmitters are usually powered by a 12V or 24V voltage rail. The loop-powered transmitter is powered by a 4-20mA loop. This type of transmitter requires a very low-power architecture because the entire solution must be powered by the loop. TI provides high-efficiency step-down converters with low quiescent current and low output ripple, suitable for line-powered and loop-powered transmitters. Battery-powered transmitters can be powered by TI's low-power buck converter and buck/boost converter designs. The DC/DC step-down converter can provide more than 95% efficiency over a large battery voltage range, while the input voltage can even be reduced to 1.8V, thereby extending battery life. A dedicated buck/boost converter can generate the required stable output voltage, can provide a constant current when the input voltage is too high or too low, and support a variety of battery configurations.
Industry Classification: Industrial Electronics
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Development Platform :
Delivery form:
Performance parameters:
Application scenarios:
