www.ti.com PCB Layer Plots Figure 80. Board Dimensions TIDU271–May 2014 Submit Documentation Feedback Temperature Sensor Interface Module for Programmable Logic Controllers (PLC) Copyright © 2014, Texas Instruments Incorporated 63
Conclusion 12 Conclusion www.ti.com Temperature sensors (such as thermocouples and RTDs) have their own advantages and disadvantages, even when they are widely used across the industrial sector. Thermocouples and RTDs generally have long wires running to a monitoring room or station. Thermocouples and RTDs generate weak analog output signals, which make measurement more difficult. Clearly, it requires precise sensor excitation, high resolution, low noise, low drift, low power, and small size ∆Σ ADC to perform the temperature sensing task. ADS1220 becomes an ideal choice for the DC sensing application as ADS1220 is equipped with two differential or four single-ended inputs, a highly flexible input multiplexer, a low noise PGA, two programmable excitation current sources, an internal reference, an internal oscillator, a low side bride switch, and a precision internal temperature sensor. ADS1220 has a SPI compatible interface and is easy to program and use. This Industrial TI Design shows how ADS1220 can be used with thermocouple and RTD in different configurations. This reference design is an effort to provide sufficient information to users who wish to develop a precision temperature measurement solution using ADS1220. 13 References 1. TIDA-0095 RTD Temperature Transmitter for 2-Wire, 4 to 20-mA Current Loop Systems, TIDU182 Application Report 2. RTD Ratiometric Measurements and Filtering Using the ADS1148 and ADS1248 Family of Devices, Application Report SBAA201 3. TI Precision Designs: 0-1A, Single-Supply, Low-Side, Current Sensing Solution, TIDU040 4. TI Precision Designs: Verified Design Hardware-Compensated Ratiometric 3-Wire RTD System, 0°C – 100°C, 0.005°C Error, TIPD152 5. TI Precision Designs: Ratiometric 3-Wire RTD Acquisition System, 0 °C – 100 °C, 0.005% FSR, SLAU520 6. Example Temperature Measurement Applications Using the ADS1247 and ADS1248, Application Report SBAA180 7. Signal Conditioning and Linearization of RTD Sensors, 2011 Texas Instruments Technology Day Presentation, Collin Wells 8. http://www.omega.com 9. https://www.wikipedia.org 14 About the Author SHARAD YADAV is a Systems Engineer at Texas Instruments India where he is responsible for developing reference design solutions for the industrial segment. Sharad has eight years of experience in high-speed digital, mixed-signal boards, low-noise analog, and EMC protection circuit design. SANKAR SADASIVAM is Chief Technologist for Industrial Systems Engineering at Texas Instruments, where he is responsible for architecting and developing reference design solutions for the Industrial segment. Sankar brings to this role his extensive experience in Analog, RF, Wireless, Signal Processing, High-speed Digital and Power electronics. Sankar earned his Master of Science (MS) in Electrical Engineering from the Indian Institute of Technology, Madras. 64 Temperature Sensor Interface Module for Programmable Logic Controllers TIDU271–May 2014 (PLC) Submit Documentation Feedback Copyright © 2014, Texas Instruments Incorporated