Evaluation Board User Guide UG-029
Rev. 0 | Page 7 of 12
RTD DEMONSTRATION CIRCUIT
The on-board RTD is measured by the primary ADC by using
the sample code in the RTD.c file. The RTD.c file is located in
the code example folder of the software CD included with the
evaluation board kit. The IEXC0 pin provides an excitation
current through the RTD. The voltage drop across the RTD
is measured differentially by ADC0 through input channels
ADC0 and ADC1. The reference resistor, R1, is connected to
the VREF+ of the ADuC7060.
For this test, set Switch 1 to Switch 4 of S4 to the on position.
Note that the ADC0/ADC1 pins and the AIN0/AIN1 pins are
the same pins in this user guide. Both sets use the function and
differ only in name.
R
REF
RTD
IEXC0
AIN0 (T+)
0.2mA~1mA
AIN1 (T–)
VREF+
VREF–
GND_SW
08322-001
Figure 1. Diagram of the RTD Circuit
