TMPSNSRD-TCPL1 Microchip Technology, TMPSNSRD-TCPL1 Datasheet - Page 19

• Manufacturer Part Number: TMPSNSRD-TCPL1
• Description: BOARD RTD REFERENCE DESIGN
• Manufacturer: Microchip Technology

Specifications of TMPSNSRD-TCPL1

• Sensor Type: Temperature, Thermocouple
• Embedded: No
• Utilized Ic / Part: MCP3421, MCP9804
• Processor To Be Evaluated: MCP9804, MCP3421
• Interface Type: USB
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Voltage - Supply: -
• Interface: -
• Sensitivity: -
• Sensing Range: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

RTD Reference Design Board
The RTD Reference Design demonstrates how to implement
Resistive Temperature Detector (RTD) and accurately
measure temperature. This solution uses the MCP3551
22-bit Analog-to-Digital Converter (ADC) to measure voltage
across the RTD. The ADC and the RTD are referenced using
an onboard reference voltage and the ADC inputs are directly
connected to the RTD terminals. This provides a ratio metric
temperature measurement. The solution uses a current
limiting resistor to bias the RTD. It provides a reliable and
accurate RTD instrumentation without the need for extensive
circuit com pensation and calibration routines.
In addition, the this reference design includes a silicon
temperature sensor, MCP9804. This sensor is used for
comparison only, it is not needed to instrument an RTD. The
MCP3551 and MCP9804 outputs are read using a USB PIC
microcontroller. This controller is also connected to a PC
using USB interface. The thermal management software is
used plot the RTD temperature data in stripchart format.
Development Tools
(TMPSNSRD-RTD2)
Thermocouple Reference Design Board
(TMPSNSRD-TCPL1)
The Thermocouple Reference Design demonstrates how
to implement a thermocouple and accurately sense
temperature over the entire thermocouple measurement
range. This solution uses the MCP3421 18-bit Analog-
to-Digital Converter (ADC) to measure voltage across the
Thermocouple. The ADC has an internal 2.048V reference
voltage and a Programmable Gain Amplifier with 1, 2, 4,
8 V/V. At a Gain of 8 V/V the PGA effec tively adds 3 LSb
to the ADC. This increases the ADC resolution to 21-bit
or 2 μV/LSb. Therefore, the Thermocouple EMF voltage is
measured with 2 μV resolution. For K-type thermocouple,
measurement system provides a ±0.05°C resolution. The
cold-junction compensation is done using a ±1°C accurate
0.0625°C resolution silicon temperature sensor, the
MCP9804. This solution provides a reliable and accurate
Thermocouple instrumentation without the need for
extensive circuit compensation and calibration routines.
Signal Chain Design Guide
19