Microchip Technology PT100 RTD, User Manual

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PT100 RTD EVALUATION
BOARD USER’S GUIDE
©
2006 Microchip Technology Inc. DS51607A-page 5
Chapter 1. Product Overview
1.1 INTRODUCTION
This chapter provides an overview of the PT100 RTD Evaluation Board and covers the
following topics:
• What is the PT100 RTD Evaluation Board?
• What the PT100 RTD Evaluation Board kit includes.
1.2 WHAT IS THE PT100 RTD EVALUATION BOARD?
The PT100 RTD Evaluation Board demonstrates how to bias a Resistive Temperature
Detector (RTD) and accurately measure temperature. Up to two RTDs can be
connected. The RTDs are biased using constant current source and the output voltage
is scaled using a difference amplifier. In addition to the difference amplifier, a multiple
input channel Programmable Gain Amplifier (PGA) MCP6S26 is used to digitally switch
between RTDs and increase the scale up to 32 times.
The output of the difference amplifier is connected to a 12-bit differential
Analog-to-Digital Converter (ADC) MCP3301. The ADC outputs serial data to the
PIC18F2550 using a Serial Peripheral Interface (SPI). The data is transmitted to a PC
using a USB interface.
A Microsoft
®
Excel
®
macro is used as a Graphical User Interface (GUI) to acquire the
data. The acquired data is stored in an Excel Worksheet and graphed as a real-time
stripchart display. In addition, the user can select input channels, acquisition interval
and stripchart display buffer size.
1.3 WHAT THE PT100 RTD EVALUATION BOARD KIT INCLUDES
This PT100 RTD Evaluation Board Kit includes:
• The PT100 RTD Evaluation Board (102-00096)
• PIC18F2550 Firmware (USB)
• Microsoft Excel-Based GUI
• PT100 RTD Evaluation Board User’s Guide (DS-51607)
• Mini-USB Cable