Microchip Technology TMPSNSRD-TCPL1 데이터 시트
THERMOCOUPLE
REFERENCE DESIGN
© 2010 Microchip Technology Inc.
DS51889A-page 9
Chapter 1. Product Overview
1.1
INTRODUCTION
The following name and assembly number are found on the Thermocouple Reference
Design’s Printed Circuit Board (PCB):
Design’s Printed Circuit Board (PCB):
• 102-00114
1.2
WHAT IS THE THERMOCOUPLE REFERENCE DESIGN?
The Thermocouple Reference Design demonstrates how to instrument 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, 8V/V. At a Gain of 8V/V the PGA effectively adds 3LSb 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.
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, 8V/V. At a Gain of 8V/V the PGA effectively adds 3LSb 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.
The ADC output is read using a PICmicro Microcontroller. This controller is also
connected to a PC using USB interface. The Thermal Management software is used to
plot the Thermocouple temperature data in stripchart format.
connected to a PC using USB interface. The Thermal Management software is used to
plot the Thermocouple temperature data in stripchart format.
1.3
WHAT THE THERMOCOUPLE REFERENCE DESIGN KIT INCLUDES
This Thermocouple Reference Design Kit includes:
• Thermocouple Reference Design, 102-00114
• K-type Thermocouple
• Important Information Sheet