TIDA-00095

RTD Temperature Transmitter for 2-wire, 4 to 20-mA Current Loop Systems

TIDA-00095

Design files

Overview

This comprehensive design provides a complete system that measures and processes temperature signals  inputs from 2-wire, 3-wire, and 4-wire resistance temperature detectors (RTDs) and outputs a 4 to 20-mA current-loop signal corresponding to the temperature processed from the RTD inputs. It is intended as a reference design for process measurement applications in factory automation, field transmitters and building automation. With less than 0.17°C maximum measured error over -200°C to 850°C, extremely low loop power consumption 1.4mA  (typical including RTD biasing currents) and IEC61000 pre compliance testing, this design significantly reduces the design time for development of high accuracy temperature transmitter systems. It also addresses system level calibration - both offset and gain that can be implemented to improve ADC and DAC accuracy as well as also includes linear interpolation to address the non-linearity of the RTD element.

Features
  • Input Compatible with 2-, 3-, and 4-wire RTD Probes
  • Low power consumption  of 1.4 mA (with RTD biasing currents) makes it ideal for loop powered systems
  • 4-20 mA current-loop signal output with 0.25 µA resolution
  • Maximum measured error: 0.11°C (-200°C to 200°C), 0.17°C (-200°C to 850°C)
  • IEC61000-4-2: ESD: Air Discharge: ±8 kV Class A, Contact Discharge ±4 kV Class A
  • IEC61000-4-4: EFT: ±2 kV Class A

Design files & products

Design files

Download ready-to-use system files to speed your design process.

TIDR389.PDF (212 K)

Detailed schematic diagram for design layout and components

TIDR390.ZIP (23 K)

Complete listing of design components, reference designators, and manufacturers/part numbers

TIDU214.PDF (257 K)

Detailed overview of design layout for component placement

TIDU215.PDF (274 K)

Detailed overview of design layout for component placement

TIDC268.ZIP (765 K)

Files used for 3D models or 2D drawings of IC components

TIDC269.ZIP (2301 K)

Design file that contains information on physical board layer of design PCB

TIDU212.PDF (1492 K)

PCB layer plot file used for generating PCB design layout

Products

Includes TI products in the design and potential alternatives.

Linear & low-dropout (LDO) regulators

TPS7A49150-mA, 36-V, low-noise, high-PSRR, adjustable low-dropout voltage regulator with enable

Data sheet document-pdfAcrobat PDF open-in-new HTML
MSP430 microcontrollers

MSP430G251316 MHz MCU with 16KB FLASH, 512B SRAM, comparator, UART/SPI/I2C, timer

Data sheet document-pdfAcrobat PDF
Precision ADCs (<=10MSPS)

ADS112016-bit, 2-kSPS, 4-ch, low-power, small-size delta-sigma ADC with PGA, VREF, 2x IDACs & SPI interface

Data sheet document-pdfAcrobat PDF open-in-new HTML
Precision ADCs (<=10MSPS)

ADS122024-bit, 2-kSPS, 4-ch, low-power, small-size delta-sigma ADC w/ PGA, VREF, 2x IDACs & SPI interface

Data sheet document-pdfAcrobat PDF open-in-new HTML
Precision DACs (<=10MSPS)

DAC161S99716-Bit Precision DAC With Internal Reference and 4mA-to-20mA Current Loop Drive

Data sheet document-pdfAcrobat PDF open-in-new HTML

Start development

Software

Firmware

TIDA-00095 Firmware – TIDC270.ZIP (54 K)

Technical documentation

star
= Top documentation selected by TI
No results found. Please clear your search and try again.
View all 4
Type Title Date
* User guide RTD Temp Transmitter for 2-Wire 4- to 20-mA Current Loop Systems (Rev. A) Feb. 11, 2014
Technical article It's in the math: how to convert an ADC code to a voltage (part 2) Apr. 29, 2016
Analog design journal Low-IQ synchronous buck converter enables intelligent field-sensor applications Apr. 26, 2016
More literature TIDA-00095 Firmware Jan. 29, 2014

Related design resources

Reference designs

REFERENCE DESIGN
TIDA-00165 Small Form Factor, 2-Wire 4 to 20mA Current Loop RTD Temperature Transmitter Reference Design TIDA-00168 Thermocouple AFE Using RTD or Integrated Temperature Sensor for Cold Junction Compensation (CJC) TIDA-00189 Isolated Loop Powered Thermocouple Transmitter Reference Design TIDA-00247 Single Chip 2-Wire Loop Powered, 4 to 20mA Current Loop RTD Temperature Transmitter Reference Design TIDA-00459 Highly Efficient Power & Data Transmission for Isolated Low Power Applications Reference Design

Support & training

TI E2E™ forums with technical support from TI engineers

View all forum topics

Content is provided "as is" by TI and community contributors and does not constitute TI specifications. See terms of use.

If you have questions about quality, packaging or ordering TI products, see TI support. ​​​​​​​​

Videos