CN0221 Datasheet, PDF (5/5 Pages) Analog Devices – Devices Connected

Circuit Note
RTD Measurement Test
To evaluate the RTD circuit and linearization source code, the
RTD on the board was replacement with an accurate, adjustable
resistance source. The instrument used was the 1433-Z Decade
Resistor. The RTD values are from 90 Ω to 140 Ω, which represents
an RTD temperature range of −25°C to +114°C.
The test setup circuit is shown in Figure 8, and the error results
for the RTD tests are shown in Figure 9.
AVDD IOVDD
0.1µF
0.1µF
1433-Z
DECADE
RESISTOR
10Ω
0.01µF
10Ω
0.01µF
R_REF
5.6kΩ
0.1%
AVDD IOVDD
AIN5/IEXC
AIN0
AIN1
ADuCM360
V_REF+
V_REF–
Figure 8. Test Setup for Measuring RTD Error
0
–0.01
–0.02
–0.03
–0.04
–0.05
–0.06
–0.07
–0.08
–0.09
–0.10
–25
–5
15
35
55
75
TEMPERATURE (°C)
95
115
Figure 9. Error in °C of RTD Measurement Using Piecewise Linearization Code
and ADC0 Measurements
CN-0221
LEARN MORE
CN0221 Design Support Package:
http://www.analog.com/CN0221-DesignSupport
ADIsimPower Design Tool.
Kester, Walt. 1999. Sensor Signal Conditioning. Analog Devices.
Chapter 7, "Temperature Sensors."
Kester, Walt. 1999. Sensor Signal Conditioning. Analog Devices.
Chapter 8, "ADCs for Signal Conditioning."
Looney, Mike. RTD Interfacing and Linearization Using an
ADuC706x Microcontroller. AN-0970 Application Note.
Analog Devices.
MT-022 Tutorial, ADC Architectures III: Sigma-Delta ADC
Basics. Analog Devices.
MT-023 Tutorial, ADC Architectures IV: Sigma-Delta ADC
Advanced Concepts and Applications. Analog Devices.
MT-031 Tutorial, Grounding Data Converters and Solving the
Mystery of "AGND" and "DGND." Analog Devices.
MT-101 Tutorial, Decoupling Techniques. Analog Devices.
ITS-90 Table for Type T Thermocouple.
Data Sheets and Evaluation Boards
ADuCM360/ADuCM361 Data Sheet
ADuCM360/ADuCM361 Evaluation Kit
ADM3202 UART to RS232 Transceiver Data Sheet
ADP120 Data Sheet
ADP1720 Data Sheet
REVISION HISTORY
4/14—Rev. B to Rev. C
Change to Circuit Function and Benefits Section ........................1
Change to Circuit Description Section .......................................... 2
Change to Common Variations Section ........................................ 4
12/13—Rev. A to Rev. B
Changes to Code Description Section ........................................... 3
8/13—Rev. 0 to Rev. A
Changes to Title................................................................................. 1
5/12—Revision 0: Initial Version
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