MCP3423 Evaluation Board User’s Guide © 2008 Microchip Technology Inc.
Note the following details of the code protection feature on Microchip devices: • Microchip products meet the specification contained in their particular Microchip Data Sheet. • Microchip believes that its family of products is one of the most secure families of its kind on the market today, when used in the intended manner and under normal conditions. • There are dishonest and possibly illegal methods used to breach the code protection feature.
MCP3423 EVALUATION BOARD USER’S GUIDE Table of Contents Preface ........................................................................................................................... 1 Introduction............................................................................................................ 1 Document Layout .................................................................................................. 1 Conventions Used in this Guide ...................................................
MCP3423 Evaluation Board User’s Guide NOTES: DS51778A-page iv © 2008 Microchip Technology Inc.
MCP3423 EVALUATION BOARD USER’S GUIDE 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.
MCP3423 Evaluation Board User’s Guide 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 MCP3423 Evaluation Board. Other useful documents are listed below. The following Microchip document is available and recommended as supplemental reference resources: PICkit™ Serial Analyzer User’s Guide (DS51647) Consult this document for instructions on how to use the PICkit Serial Analyzer hardware and software.
MCP3423 Evaluation Board User’s Guide NOTES: DS51778A-page 4 © 2008 Microchip Technology Inc.
MCP3423 EVALUATION BOARD USER’S GUIDE Chapter 1. Quick Start Instructions 1.1 INTRODUCTION The following sections provide an overview of the MCP3423 Evaluation Board and demonstrate how to use it with the PICkit™ Serial Analyzer (P/N: DV164122). The following topics are covered: • Description of the MCP3423 Evaluation Board • How to use MCP3423 Evaluation Board with the PICkit Serial Analyzer 1.
MCP3423 Evaluation Board User’s Guide FIGURE 1-1: 1.3 Front View of the MCP3423 Evaluation Board. GETTING STARTED WITH PICKIT SERIAL ANALYZER Figure 1-1 shows the MCP3423 Evaluation Board, and Figure 1-2 shows the MCP3423 and PICkit Serial Analyzer. The following describes how to use them together: 1. Connect the MCP3423 Evaluation Board’s 6-pin socket to the PICkit Serial Analyzer as shown in Figure 1-2. 2. Connect the oscilloscope probes to the SCL and SDA test pins (optional). 3.
Quick Start Instructions 6. Connecting the analog inputs: If you need to measure a single-ended input, connect the unused pin (example, CHx-) to VSS. • Connecting the inputs: The MCP3423 Evaluation Board has input pads for two analog input channels. You can connect all inputs at the same time and multiplex the input channel using configuration register settings. You can also leave the unused channel inputs floating. 7. Use the PICkit Serial Analyzer PC GUI to send I2C write and read commands.
MCP3423 Evaluation Board User’s Guide Personal Computer USB Cable Connected between the PICkit Serial Analyzer and Personal Computer PICkit Serial Analyzer Sensor Input Connectors MCP3423 Evaluation Board FIGURE 1-2: MCP3423 Evaluation Board with the PICkit Serial Analyzer. 1.3.1 PICkit Serial Analyzer PC Software Setup for the MCP3423 Evaluation Board The following steps describe how to set up and use the PICkit Serial Analyzer PC Graphic User Interface (GUI). 1.
Quick Start Instructions FIGURE 1-3: PICkit Serial Analyzer Configuration Window welcome window. Click the Next button and follow the instructions. 4. Select the Communication Mode type: I2C Master, and click the Next button. FIGURE 1-4: © 2008 Microchip Technology Inc. Step 1 - Communication Mode selection.
MCP3423 Evaluation Board User’s Guide 5. In the new window, select “100 kHz” or “400 kHz”. Either one will be fine. Click the Next button. FIGURE 1-5: Note: DS51778A-page 10 Step 2 - I2C Communication Speed window. The MCP3423 device supports the I2C bus data rate up to 3.4 MHz, but the current version of the PICkit Serial Analyzer supports the I2C bus data rate up to 400 kHz only. © 2008 Microchip Technology Inc.
Quick Start Instructions 6. In the Device Pullups window, select No on “Enable Pull-ups” and click the Next button. Note: The MCP3423 Evaluation Board has its own pull-up resistors. FIGURE 1-6: Step 3 - Device Pullups window. 7. In this step, you have to select the VDD voltage of the MCP3423 Evaluation Board, then click the Next button.
MCP3423 Evaluation Board User’s Guide FIGURE 1-7: Step 4 - Voltage Source selection window. 8. Click the OK button. You have made all of the PICkit Serial Analyzer Configuration Setups. You are now ready to program the MCP3423 Evaluation Board using the PICkit Serial Analyzer. FIGURE 1-8: DS51778A-page 12 Configuration Wizard - Finishing step. © 2008 Microchip Technology Inc.
Quick Start Instructions 1.3.2 Creating Script Files In order to make a communication connection between the PICkit Serial Analyzer and the MCP3423 Evaluation Board, a script file is needed. Figure 1-9 shows how to create script files and how to use them. • In the PICkit Serial Analyzer window, select from the menu Communications> Script>Script Builder . FIGURE 1-9: Creating a script file with Script Builder. 1.3.2.1 CREATING SCRIPT FILE FOR CONFIGURATION BYTE WRITING 1.
MCP3423 Evaluation Board User’s Guide 1. 2. 3. FIGURE 1-10: To change value: • Click this box and type a new value To delete or Insert a new box: • Choose the box and right click the mouse button for options available Make sure the listed parameters in “script Detail” are in the exact order as shown here. Modifying parameters in Script Builder window. 4.
Quick Start Instructions Bytes to to send send 22 Bytes Address Byte Configuration Byte (9C) Note: The “9C” in the configuration byte selects the following options: - FIGURE 1-11: Conversion Mode: Continuous Conversion Channel Selection: Channel 1 Bit Resolution: 18 bits Gain Selection: 1x Script file example for I2C Write Command. 1.3.2.2 SAVE THE SCRIPT FILE AND PROGRAMMING THE MCP3423 CONFIGURATION REGISTER 1. Change the 2nd and 3rd data bytes you want in the Script Detail. 2.
MCP3423 Evaluation Board User’s Guide 5. You can also see the SCL and SDA waveforms using the Oscilloscope. Note: When you click on the “Execute Script” menu, the “Busy” LED on the PICkit Serial Analyzer will momentarily turn on and then turn off. If the LED remains ON, a communications problem has occurred.
Quick Start Instructions 1.3.3 Trouble Shooting: If the device does not acknowledge the commands If the device is powered up initially with unstable VDD from the PICKit Serial, there is a chance that the device can latch a wrong address bits from the external address pins, and therefore it may not acknowledge the command bytes correctly since the address bits are not matched. In this case, send a General Call Latch Command after the VDD is stabilized (after about 20 seconds the PICKit Serial is powered).
MCP3423 Evaluation Board User’s Guide 1.3.4 Reading the Conversion Data using the PICkit Serial Analyzer You can read back the conversion data with the following steps. 1.3.4.1 1. CREATING SCRIPT FILE TO READ CONVERSION DATA Click on ReadAddrA8 in “Example I2C Scripts” column. This will result in filling in the spaces under “Script Detail” column. Now you can modify the parameter boxes (delete or insert) in the “Script Detail” column with options.
Quick Start Instructions Address Byte Requesting 5 Bytes FIGURE 1-14: Script File sample to read conversion data. 3. Type in any script name (i.e., MCP3423_Read) in the space below the “Script Name” menu. 4. Click Save Script button. 5. Click Execute Script button. Note: At this point, the PICkit Serial transmits the I2C Read Command to the MCP3423 device. The saved file name will appear in “Users I2C Scripts” column, and can be re-used any time by selecting the file name. 6.
MCP3423 Evaluation Board User’s Guide Requesting 5 Bytes Reading Data using a Read Command 5th Byte: Repeated Byte for Configuration byte 4th byte: Configuration Byte (note that RDYbit is “0”) 3rd byte: Data Byte 2nd byte: Data Byte 1st byte: Data Byte Results: Output code: F907 in hex ( = 63751 in decimal) Output Voltage= 15.625 μV ( LSB ) 63751 × -------------------------------------------- = 0.
Quick Start Instructions Zoom-in Data Bytes = 00F907 (hex) (a) Read command and outputs. The 3 data bytes are zoomed in for better clarity. Zoom-in 4th Byte 5th Byte Configuration Byte (4th) and Repeated Configuration Byte (5th) (b) Read command and outputs. The last two data bytes are zoomed in for better clarity. FIGURE 1-16: Read Command and Data on I2C bus. Note the RDY bit in 4th byte is “0”. This means the conversion data just read is the latest conversion data.
MCP3423 Evaluation Board User’s Guide 1.4 EXPERIMENT FOR CH2 Repeat the instructions from Section 1.3.2 “Creating Script Files” to Section 1.3.4 “Reading the Conversion Data using the PICkit Serial Analyzer” for the input channel 2. DS51778A-page 22 © 2008 Microchip Technology Inc.
MCP3423 EVALUATION BOARD USER’S GUIDE Appendix A. Schematic and Layouts A.1 INTRODUCTION This appendix contains the following schematics and layouts for the MCP3424 Evaluation Board: • • • • • Board – Schematic Board – Top Layer Board – Top Metal Layer Board – Bottom Layer Board – Bottom Metal Layer © 2008 Microchip Technology Inc.
MCP3423 Evaluation Board User’s Guide A.2 BOARD – SCHEMATIC DS51778A-page 24 © 2008 Microchip Technology Inc.
Schematic and Layouts A.3 BOARD – TOP LAYER © 2008 Microchip Technology Inc.
MCP3423 Evaluation Board User’s Guide A.4 BOARD – TOP METAL LAYER DS51778A-page 26 © 2008 Microchip Technology Inc.
Schematic and Layouts A.5 BOARD – BOTTOM LAYER © 2008 Microchip Technology Inc.
MCP3423 Evaluation Board User’s Guide A.6 BOARD – BOTTOM METAL LAYER DS51778A-page 28 © 2008 Microchip Technology Inc.
MCP3423 EVALUATION BOARD USER’S GUIDE Appendix B. Bill of Materials (BOM) TABLE B-1: Qty BILL OF MATERIALS (BOM) Reference Description Manufacturer Part Number 1 C1 CAP .1UF 25V CERAMIC X7R 0805 Panasonic® - ECG ECJ-2VB1E104K 1 C2 CAP CERAMIC 10UF 6.3V X5R 0805 Panasonic - ECG ECJ-2FB0J106K 1 D1 LED RED ORANGE CLEAR 0805 SMD LITE-ON INC LTST-C170EKT 2 R1,R3 RES 4.
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