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MCP42XX

PICtail™ Plus

Daughter Board

User’s Guide

Summary of content (46 pages)

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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.
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MCP42XX PICTAIL™ PLUS DAUGHTER BOARD USER’S GUIDE Table of Contents Preface ........................................................................................................................... 1 Introduction............................................................................................................ 1 Document Layout .................................................................................................. 1 Conventions Used in this Guide .......................................
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MCP42XX PICTAIL™ PLUS DAUGHTER 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.
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MCP42XX PICtail™ Plus Daughter 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...
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Preface RECOMMENDED READING This user's guide describes how to use MCP42XX PICtail Plus Daughter Board User’s Guide. Other useful documents are listed below. The following Microchip documents are available and recommended as supplemental reference resources.
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MCP42XX PICTAIL™ PLUS DAUGHTER BOARD USER’S GUIDE Chapter 1. Product Overview 1.1 INTRODUCTION The MCP42XX PICtail Plus Daughter Board demonstrates the features and abilities of Microchip’s MCP41XX and MCP42XX Digital Potentiometers. This board is designed to exclusively use the MCP42XX devices. The MCP41XX and MCP42XX are Digital Potentiometers with an SPI interface.
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MCP42XX PICtail™ Plus Daughter Board User’s Guide 1.2 WHAT IS THE MCP42XX PICTAIL PLUS DAUGHTER BOARD? The MCP42XX PICtail Plus Daughter Board is used to demonstrate the use of Digital Potentiometers. This board is designed to be used in conjunction with either the PIC24 Explorer 16 Demo Board or the PICkit™ Serial Analyzer. Figure 1-1 shows the boards component placement and the purpose of the jumpers. The board has an MCP4261-103 (10 kΩ) device for evaluation. This device is in the TSSOP package (U2).
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Product Overview Some of the features of the board include: • PICkit Serial Analyzer Interface (J1) • PICtail Plus Interface (J3) • MAX4582L High Voltage analog switch to allow CS voltage to be selected as one of four voltages (VSS, 3.3V, 5.0V, or 9.
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MCP42XX PICTAIL™ PLUS DAUGHTER BOARD USER’S GUIDE Chapter 2. Installation and Operation 2.1 INTRODUCTION The MCP42XX PICtail Plus Daughter Board is used to demonstrate the operation of Digital Potentiometer. The operation of the MCP41XX devices is similar to the MCP42XX devices. Therefore, this demo board can be used as a development platform for either device family. This board is designed to be used in conjunction with either the PIC24 Explorer 16 Demo Board or the PICkit™ Serial Analyzer. 2.
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MCP42XX PICtail™ Plus Daughter Board User’s Guide 2.3 GETTING STARTED Figure 2-1 shows a simplified circuit for the MCP42XX PICtail Plus Daughter Board. The layout of the board is shown in Figure 2-3. This board can be operated with either a PICDEM board with a PICtail Plus header or the PICkit Serial Analyzer. The MCP42XX PICtail Plus Daughter Board kit comes with firmware for the Explorer 16 Starter Kit (DV164033). The layout of this board is shown in Figure 2-5.
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Installation and Operation 2.3.1 The Hardware Figure 2-2 shows the component placement of the MCP42XX PICtail Plus Daughter Board as well as the operation of the board jumpers. The VAx and VBx pads allow an external voltage source to be applied to the device’s desired Terminal A or Terminal B pin. The VWx pad is directly connected to the corresponding Terminal W pin, which makes it easy to measure the resulting voltage.
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MCP42XX PICtail™ Plus Daughter Board User’s Guide JMP1:JMP3 Terminal A Source VAx Pad JMP2:JMP4 Terminal B Source AVDD VBx Pad VSS JP3 - PIC24 AN1 pin AN1 connected to W1 AN1 not connected JP2 - PIC24 AN0 pin FIGURE 2-2: DS51759A-page 12 JP1 - Explorer 16 5V signal to AVDD plane AN0 connected to W0 Explorer 16 5V signal connected to MCP42XXDM-PTPLS AVDD plane AN0 not connected Explorer 16 5V signal not connected to MCP42XXDM-PTPLS AVDD plane MCP42XXDM-PTPLS Jumper Configuration and Oscilloscop
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Installation and Operation FIGURE 2-3: MCP42XX PICtail Plus Daughter Board Layout with Default Jumper Settings Note: © 2008 Microchip Technology Inc. This is the Jumper configuration that the board should be shipped with.
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MCP42XX PICtail™ Plus Daughter Board User’s Guide 2.4 EXPLORER 16 DAUGHTER DEMO BOARD DEMOS This section describes how to demonstrate the MCP42XX PICtail Plus Daughter Board. The demos will either use an Explorer 16 Developers Board or a PICkit Serial Analyzer. The demo using the Explorer 16 Developers Board is discussed in Section 2.4.1 “Demos with the Explorer 16 Starter Kit”. While the demo using the PICkit Serial Analyzer is discussed in Section 2.4.2 “Demo with the PICkit Serial Analyzer”. Note: 2.4.
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Installation and Operation 2.4.1.1 THE MCP42XXDM-PTPS JUMPER CONFIGURATION Before inserting the board into the Explorer 16 Developers Board, the jumper configuration must be verified. Figure 2-4 shows the configurations of the jumpers. Channel 1 Channel 4 (Program 2 SDO Signal) Channel 4 Channel 3 Channel 2 FIGURE 2-4: MCP4XXDM-PTPLS Jumper Configuration and Oscilloscope Test Points. Note: © 2008 Microchip Technology Inc. This is the Jumper configuration that the board should be shipped with.
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MCP42XX PICtail™ Plus Daughter Board User’s Guide 2.4.1.2 MCP42XX PICTAIL PLUS DAUGHTER BOARD (MCP42XXDM-PTPLS) INTO THE EXPLORER 16 STARTER KIT (DV164033) Figure 2-5 shows the component placement on the Explorer 16 Demo Board including the PICtail Plus header that the MCP42XX PICtail Plus Daughter Board is inserted into. The boards Reset switch and other switches are pointed out. Ensure that the MCP42XXDM-PTPLS is installed in the correct orientation into the Explorer 16 Developers Board.
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Installation and Operation 2.4.1.3 DEMO STEPS The PIC24 Board firmware contains two programs. The program selected is determined after a reset (including the Power-on reset) by the state of the S3 switch. The programs are: 1. Wiper 1 Saw Wave (Switch S3 not depressed). 2. Increment / Decrement with High Voltage Write to Non-Volatile Wiper 1 Register (Switch S3 depressed). Table 2-2 shows the sequence of steps to demo the MCP42XXDM-PTPLS board with the Explorer 16 Developer’s Board.
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MCP42XX PICtail™ Plus Daughter Board User’s Guide TABLE 2-2: Step Action Result 10 Depress the Explorer 16 Developer Board’s S6 While S6 is depressed, the voltage push button on Wiper 1 (VW1) increases 11 Depress the Explorer 16 Developer Board’s S4 While S4 is depressed, the voltage push button on Wiper 1 (VW1) decreases 12 Use the S4 and S6 push buttons to configure — the volatile wiper 1 register to either near VDD or near VSS. Take note of Wiper Voltage value.
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Installation and Operation FIGURE 2-6: Screen Capture of Program 1 Output Waveforms. FIGURE 2-7: Screen Capture of Program 2 Non-Volatile Write Waveform. © 2008 Microchip Technology Inc.
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MCP42XX PICtail™ Plus Daughter Board User’s Guide 2.4.2 Demo with the PICkit Serial Analyzer Note: For information on how to use the PICkit Serial Analyzer, or any other aspect of the PIC® Development tool platform, please refer to the appropriate documentation. This demo requires that you have previously installed the PICkit Serial Analyzer (DV164122) on your computer. Ensure that the device has properly been installed before using the Supplied GUI for the MCP41XX/42XX devices.
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Installation and Operation 2.4.2.1 THE GUI SCREENS AND GUI CONFIGURATION Figure 2-8 shows the GUI when the application is first started. FIGURE 2-8: 1st Screen of GUI. Figure 2-9 shows the GUI box where the SPI Baud Rate is specified. Clicking on the “Set Baud” button results in an actual Baud Rate of 9.62 kHz, as shown in Figure 2-10. This reflects the actual Baud Rate based on the PICkit Serial Analyzer’s clock frequency. FIGURE 2-9: © 2008 Microchip Technology Inc.
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MCP42XX PICtail™ Plus Daughter Board User’s Guide FIGURE 2-10: Configuring the Baud Rate - Actual Baud Rate. To display the data values in hexidecimal, click on the Hex radial button. To Chip Select the MCP42XX device, click on the “Disable CS” button. The GUI window will now look like Figure 2-11. To have access to more control of the MCP42XX memory, click on the Advanced tab, and the GUI will display Figure 2-12. FIGURE 2-11: DS51759A-page 22 Enabling The MCP42XX Chip Select.
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Installation and Operation FIGURE 2-12: Advance Screen. Clicking on the Read Button should display the register values shown in Figure 2-13. The volatile wiper value should match the Non-volatile wiper value. Note: The Volatile/Non-Volatile wiper values may not be the device’s expected Mid-scale value due to board production testing. To write to a desired register, in the desired data entry box and click on the Write button. Figure 2-14 shows an example of writing to the Volatile Wiper 0 register.
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MCP42XX PICtail™ Plus Daughter Board User’s Guide FIGURE 2-14: DS51759A-page 24 Advance Screen - Write Register. © 2008 Microchip Technology Inc.
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Installation and Operation Figure 2-15 shows the connections for the Demo using the PICkit Serial Analyzer. Insert PICkit Serial Analyzer into this Header Channel 1 FIGURE 2-15: PICkit Serial Analyzer Demo Jumper Configuration and Oscilloscope Test Points. © 2008 Microchip Technology Inc.
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MCP42XX PICtail™ Plus Daughter Board User’s Guide 2.4.2.2 DEMO STEPS The use of the PICkit Serial Analyzer means that wiper pin’s voltage is under direct control from the PC’s GUI interface and more user experimentation is possible.
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Installation and Operation TABLE 2-4: Step 16 17 DEMO STEPS USING THE PICDEM HPC EXPLORER DEMO BOARD (CONTINUED) Action Now write values to the TCON register (bit 7 to bit 4) and monitor the effects on the VW1 pin. Result The different Potentiometer terminals (A1, W1, and B1), will be either connected or disconnected depending on the value.
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MCP42XX PICTAIL™ PLUS DAUGHTER BOARD USER’S GUIDE Appendix A. Schematic and Layouts A.1 INTRODUCTION This appendix contains the schematics and layouts for the MCP42XX PICtail Plus Daughter Board. Diagrams included in this appendix: • • • • • • A.2 Board - Schematic Board - Top Silk-screen Layer Board - Top Component Plus Silk-screen Board - Ground Layer Board - Power Layer Board - Bottom Layer SCHEMATICS AND PCB LAYOUT Figure A.3 shows the schematic of the MCP42XX PICtail Plus Daughter Board. Figure A.
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MCP42XX PICtail™ Plus Daughter Board User’s Guide BOARD - SCHEMATIC M A.3 DS51759A-page 30 © 2008 Microchip Technology Inc.
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MCP42XX PICtail™ Plus Daughter Board User’s Guide A.5 BOARD – TOP COMPONENTS + SILK-SCREEN DS51759A-page 32 © 2008 Microchip Technology Inc.
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MCP42XX PICtail™ Plus Daughter Board User’s Guide A.7 BOARD – POWER LAYER DS51759A-page 34 © 2008 Microchip Technology Inc.
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MCP42XX PICTAIL™ PLUS DAUGHTER 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 1.0UF 16V CERAMIC X7R 0805 Kemet® Electronics C0805C105K4RACTU 1 J1 CONN HEADER 6POS .100 VERT TIN Molex/Waldom® Electronics Corp 22-28-4060 3 JP1, JP2, JP3 CONN HEADER 2POS .
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MCP42XX PICTAIL™ PLUS DAUGHTER BOARD USER’S GUIDE Appendix C. Board Testing C.1 INTRODUCTION The MCP42XX PICtail Plus Daughter Board can be used in multiple configurations. Only a subset of these configurations are tested. The tests were performed with the configuration shown in Figure C-1. The tested nodes are Channel 1 through Channel 4. Other configurations, Pad connections, and circuit performance are not tested.
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MCP42XX PICtail™ Plus Daughter Board User’s Guide C.2 WHAT IS TESTED The following portions of the board are tested: • MCP4261 (U2) - U2 MCP4261 Pot 1 is tested in Potentiometer configuration. • JMP3 (P1 – P2) - AVDD to P1A • JMP4 (P1 – P2) - AVSS to P1B • MAX4582 (U1) - Y0 (5.0V), Y3 (9.0V), and Y2 (VSS) switching. • Pads: VW1 C.
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