Thermocouple Reference Design © 2010 Microchip Technology Inc.
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THERMOCOUPLE REFERENCE DESIGN Table of Contents Preface ........................................................................................................................... 5 Introduction............................................................................................................ 5 Document Layout .................................................................................................. 5 Conventions Used in this Guide ...........................................................
Thermocouple Reference Design NOTES: DS51889A-page 4 © 2010 Microchip Technology Inc.
THERMOCOUPLE REFERENCE DESIGN Preface NOTICE TO CUSTOMERS All documentation becomes dated, and this manual is no exception. Microchip tools and documentation are constantly evolving to meet customer needs, so some actual dialogs and/or tool descriptions may differ from those in this document. Please refer to our web site (www.microchip.com) to obtain the latest documentation available. Documents are identified with a “DS” number.
Thermocouple Reference Design CONVENTIONS USED IN THIS GUIDE This manual uses the following documentation conventions: DOCUMENTATION CONVENTIONS Description Arial font: Italic characters Represents Referenced books Emphasized text A window A dialog A menu selection A field name in a window or dialog A menu path MPLAB® IDE User’s Guide ...is the only compiler...
Preface RECOMMENDED READING This user's guide describes how to use Thermocouple Reference Design. Other useful documents are listed below. The following Microchip documents are available and recommended as supplemental reference resources. MCP3421 Data Sheet, “18-Bit Analog-to-Digital Converter with I2C Interface and On-Board Reference“ (DS22003). This data sheet provides detailed information regarding the MCP3421 device. THE MICROCHIP WEB SITE Microchip provides online support via our web site at www.
Thermocouple Reference Design NOTES: DS51889A-page 8 © 2010 Microchip Technology Inc.
THERMOCOUPLE REFERENCE DESIGN 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): • 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.
Thermocouple Reference Design NOTES: DS51889A-page 10 © 2010 Microchip Technology Inc.
THERMOCOUPLE REFERENCE DESIGN Chapter 2. Installation and Operation 2.1 INTRODUCTION The Thermocouple Reference Design demonstrates Microchip’s solution to accurately measure temperature using a Thermocouple and an 18-bit ADC, MCP3421. This solution eliminates the need for the traditional analog instrumentation system calibration or gain and offset trimming techniques. In addition, the Thermocouple linearization techniques can be implemented in firmware or software.
Thermocouple Reference Design 2.3 GETTING STARTED This section describes how to quickly configure the Thermocouple Reference Design. A simplified block diagram of the configuration is provided in Figure 2-1. Thermocouple Reference Design Thermal Pad USB Thermocouple PC PIC18F2550 USB PIC Microcontroller 2 MCP3421 18-Bit ADC 2 MCP9804 Temperature Sensor FIGURE 2-1: Thermocouple Reference Design Simplified Block Diagram. 2.3.1 Hardware Setup 1. Connect the USB cable to PC. 2.
Installation and Operation 2.3.2 Software Setup Once the USB interface is secured, start the Thermal Management Software. When the software starts, if the hardware is successfully detected then the GUI will be displayed. FIGURE 2-2: Thermocouple Reference Design GUI. This configuration window allows the user to set some of parameters, such as measurement unit and calibration temperature. The Play, Stop and Reset icons can be used to perform continuous data-log.
Thermocouple Reference Design The Data Acquisition charting tool can be customized by double clicking the chart, as shown in Figure 2-4. Additional options are available by right-clicking the chart. The user can also zoom into a specific plot range by clicking and dragging the section. The data in the chart can also be exported using the Export button. FIGURE 2-4: DS51889A-page 14 Chart Setup Options. © 2010 Microchip Technology Inc.
Installation and Operation 2.3.3 Sensor Calibration and Setup 2.3.3.1 THERMOCOUPLE CALIBRATION The Thermocouple sensor can be calibrated using the GUI. Once the Thermocouple sensor is exposed to the desired calibration temperature, simply type in the temperature in the Calibration Temperature field and click the Calibrate button.
Thermocouple Reference Design NOTES: DS51889A-page 16 © 2010 Microchip Technology Inc.
THERMOCOUPLE REFERENCE DESIGN Appendix A. Schematic and Layouts A.1 INTRODUCTION This appendix contains the following schematics and layouts for the Thermocouple Reference Design: • • • • • Board - Schematic Board -Top Silk and Pads Board - Internal VDD Layer Board - Internal Ground Layer Board - Bottom Silk and Pads © 2010 Microchip Technology Inc.
Thermocouple Reference Design BOARD - SCHEMATIC M A.2 DS51889A-page 18 © 2010 Microchip Technology Inc.
Schematic and Layouts A.3 BOARD -TOP SILK AND PADS A.4 BOARD - INTERNAL VDD LAYER © 2010 Microchip Technology Inc.
Thermocouple Reference Design A.5 BOARD - INTERNAL GROUND LAYER A.6 BOARD - BOTTOM SILK AND PADS DS51889A-page 20 © 2010 Microchip Technology Inc.
THERMOCOUPLE REFERENCE DESIGN Appendix B. Bill of Materials TABLE B-1: Qty BILL OF MATERIALS Reference Designator Description Manufacturer Part Number Manufacturer 1 — Ready-Made Insulated Thermocouples with OMEGA® Kapton, PFA, Glass Braid Insulation and Molded Connectors 3 C1, C5, C16 CAP .1UF 25V CERAMIC X7R 0805 Panasonic® - ECG ECJ-2VB1E104K 1 C2 CAP 1.0UF 16V CERAMIC X7R 0805 Kemet® Electronics Corp.
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