MCP46XXEV Evaluation Board User’s Guide © 2010 Microchip Technology Inc.
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MCP46XXEV EVALUATION BOARD USER’S GUIDE Table of Contents Preface ........................................................................................................................... 1 Chapter 1. Product Overview 1.1 Introduction ..................................................................................................... 5 1.2 What is the MCP46XXEV Evaluation Board? ................................................ 5 1.3 What the MCP46XXEV Evaluation Board Kit Includes .......................
MCP46XXEV Evaluation Board User’s Guide NOTES: DS51929A-page 4 © 2010 Microchip Technology Inc.
MCP46XXEV 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.
MCP46XXEV Evaluation Board User’s Guide CONVENTIONS USED IN THIS GUIDE This manual uses the following documentation conventions: DOCUMENTATION CONVENTIONS Description Arial font: Italic characters Initial caps Quotes Underlined, italic text with right angle bracket Bold characters N‘Rnnnn Text in angle brackets < > DS51929A-page 6 Represents Examples 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 ...
Preface RECOMMENDED READING This user’s guide describes how to use the MCP46XXEV Evaluation Board. Other useful documents are listed below. The following Microchip documents are available and recommended as supplemental reference resources.
MCP46XXEV Evaluation Board User’s Guide DOCUMENT REVISION HISTORY Revision A (March 2010) • Initial Release of this Document. DS51929A-page 8 © 2010 Microchip Technology Inc.
MCP46XXEV EVALUATION BOARD USER’S GUIDE Chapter 1. Product Overview 1.1 INTRODUCTION This chapter provides an overview of the MCP46XXEV Evaluation Board and covers the following topics: • What is the MCP46XXEV Evaluation Board? • What the MCP46XXEV Evaluation Board kit includes 1.2 WHAT IS THE MCP46XXEV EVALUATION BOARD? The MCP46XXEV Evaluation Board allows the system designer to quickly evaluate the operation of Microchip Technology’s MCP4661 Digital Potentiometer device.
MCP46XXEV Evaluation Board User’s Guide Connected to Ground Plane Connected to Power Plane 0Ω 4661 MCP4661-103E/ST installed in U3 (TSSOP-14 package bottom aligned to TSSOP-20 footprint) 10kΩ 10kΩ 0Ω Through hole Test Point (Orange) Wiper 1 Two Blue Wire Jumpers to connect PICkit™ Serial interface (I2C) to device pins 0Ω Through hole Test Point (Orange) Wiper 0 0Ω 1x6 Male Header, with 90° right angle FIGURE 1-1: MCP46XXEV Evaluation Board Using the TSSOP20EV Evaluation Board (MCP4661 installed
MCP46XXEV EVALUATION BOARD USER’S GUIDE Chapter 2. Installation and Operation 2.1 INTRODUCTION The MCP46XXEV Evaluation Board allows the system designer to quickly evaluate the operation of the MCP4661 10 kΩ (-103) digital potentiometer device using the PICkit Serial Analyzer. The PICkit Serial Analyzer is available separately (order number: DV164122). This board is a minimum configuration for the device.
MCP46XXEV Evaluation Board User’s Guide 2.
Installation and Operation 2.3 GETTING STARTED The MCP46XXEV Evaluation Board allows quick evaluation of the MCP4661-103E/ST device. The understanding of the device characteristics (such as the resistor network) is applicable to any of the devices in the MCP46XX family. The MCP4661-103 device has a typically RAB resistance of 10 kΩ.
MCP46XXEV Evaluation Board User’s Guide P1 P2 DIP-20 (1) P9 PICkit™ Serial / ICSP™ Interface J1 NC VDD VSS SDA SCL NC NC VDD VSS SDI SCK SDO 1 P20 20 P19 19 2 P12 9 12 P11 10 11 Requires blue wire jumpering to connect the PICkit™ Interface to the selected device P10 R1U TSSOP-20 (1) VDD 20 2 19 9 12 10 11 VSS P1 R1D 1 C2 C1 R2U P2 R2D P19 P11 R19U P20 SSOP-20 P1 1 20 2 19 XTAL P9 P12 P2 P10 9 12 VIA1 10 11 C3 VIA2 P19 R19D C4 R20U P20 PIC® Circuitry (bottom o
Installation and Operation MCP4661-103E/ST Installed in U3 (TSSOP-14 package bottom aligned to TSSOP-20 footprint) Connected to Connected to Ground Plane Power Plane 4361 0Ω 10kΩ 10kΩ 0Ω Through hole Test Point (Orange) Wiper 1 0Ω Through hole Test Point (Orange) Wiper 0 0Ω Two Blue Wire Jumpers to connect PICkit™ Serial interface (I2C) to device pins 1x6 Male Header, with 90° right angle FIGURE 2-2: MCP46XXEV Evaluation Board Component Placement Using the TSSOP20EV Evaluation Board (Top).
MCP46XXEV Evaluation Board User’s Guide TABLE 2-1: INSTALLED PASSIVE COMPONENTS (2) Component Description Comment R11U, R17U 0Ω SMT 805 Pull-up resistor R14U, R15U 10 kΩ SMT 805 Pull-up resistor R7D, R13D 0Ω SMT 805 Pull-down resistor (1) U3 MCP4661-103E/ST RAB(TYP) = 10 kΩ P9, P12 Test Point - through hole connector (Orange) J1 1x6 Male Header, 100 mil spacing 90° angle.
Installation and Operation TABLE 2-2: OPTIONAL PASSIVE COMPONENTS - NOT INSTALLED (2) Component Comment C1, C2 Power supply bypass capacitors (3) C3, C4 PIC® MCU Crystal capacitors R1U, R2U, R3U, R4U, R5U, R6U, R7U, R8U, R9U, R12U, R13U, R16U, R18U, R19U, R20U Pull-up resistor R1D, R2D, R3D, R4D, R5D, R6D, R8D, R9D, R10D, R11D, R12D, R14D, R15D, R16D, R17D, R18D, R19D, R20D Pull-down resistor (1) U1, U2 Alternate package footprints VDD, GND Power and Ground plane connection points Y1 Can con
MCP46XXEV Evaluation Board User’s Guide 2.4.2 The MCP4661 Device To make variations to the commands sent to the MCP4661 device (from the commands shown in the demo section), one must know the device memory map (see Table 2-3) and the command formats (see Figure 2-3 through Figure 2-5). For additional device operational information, refer to the MCP4661 device data sheet (DS22107).
Installation and Operation Write bit Variable Address Fixed Address S 0 1 0 Repeated Start bit Device Memory Address 1 A2 A1 A0 0 A Command AD AD AD AD 3 2 1 0 1 1 x X A Sr READ Command Control Byte STOP bit Read bit 0 1 0 1 A2 A1 A0 1 A Read Data bits 0 0 0 0 0 0 Control Byte 0 D8 A1 D7 D6 D5 D4 D3 D2 D1 D0 A2 P Read bits Note 1: Master Device is responsible for A / A signal. If an A signal occurs, the MCP45XX/46XX will abort this transfer and release the bus.
MCP46XXEV Evaluation Board User’s Guide 2.5 CONFIGURING THE PICkit™ SERIAL ANALYZER 2.5.1 Modifying the “CommScripts.txt” file Example 2-1 shows the User Scripts that need to be added to the PICkit serial’s CommScripts.txt file. The default install location of this file is: C:\Program Files\Microchip\PICkit Serial Analyzer Once these are saved in the CommScripts.txt file and the Master SPI mode is selected as the communication mode, these User Scripts will be available to select from.
Installation and Operation 2.5.2 Working With the PICkit™ Serial Analyzer Figure 2-6 shows the PICkit Serial Window after the program has started. The Transaction window indicates if the PICkit Serial GUI located the PICkit Serial Analyzer hardware. When starting the PICkit Serial Analyzer for the first time, some setup questions may be asked. If you have any questions, please refer to the PICkit Serial Analyzer documentation, available at www.Microchip.com/PICkitSerial.
MCP46XXEV Evaluation Board User’s Guide We need to select the PICkit Serial Analyzer GUI to be in I2C Master mode. Figure 2-7 shows how to select the proper mode. Select PICkit Serial Analyzer -> Select Communications Mode -> I2C Master menu item (make sure the I2C Master item is checked). FIGURE 2-7: DS51929A-page 22 PICkit™ Serial Selecting Communications Mode. © 2010 Microchip Technology Inc.
Installation and Operation Now we need to configure the mode that we selected. Figure 2-8 shows how to open the Communications Mode window. Select PICkit Serial Analyzer -> Configure Communications Mode menu item. This will open a new window: FIGURE 2-8: PICkit™ Serial - Opening the Communications Mode Window. © 2010 Microchip Technology Inc.
MCP46XXEV Evaluation Board User’s Guide Figure 2-9 shows the Configure Communications Mode window in Basic view while Figure 2-10 shows the Configure Communications Mode window in Advanced view. Ensure that your window options and settings are the same as this window, and then select the Save Changes button. The Configure Communications Mode window may now be closed. Ensure that the pull-ups are enabled, the board is powered if necessary, and the desired I2CM bit rate has been selected.
Installation and Operation FIGURE 2-10: PICkit™ Serial Configure Communications Mode window - Advanced View. © 2010 Microchip Technology Inc.
MCP46XXEV Evaluation Board User’s Guide Now we are going to open the Script Builder window, select the Communications -> Script -> Script Builder menu item (see Figure 2-11). FIGURE 2-11: DS51929A-page 26 PICkit™ Serial - Script Builder Menu Selection. © 2010 Microchip Technology Inc.
Installation and Operation The Script Builder window is shown in Figure 2-12. In this window we see the User I2CM Scripts including the ones that were added to the CommScripts.txt file. FIGURE 2-12: PICkit Serial Script Builder Window. © 2010 Microchip Technology Inc.
MCP46XXEV Evaluation Board User’s Guide Double clicking on the MCP4661W0WR User I2CM Script will load the script details. Figure 2-13 shows what the values mean in the Script Details. These values are hex numbers. The first value (03h), is the number of bytes that will be written. The second byte (5Eh) is the MCP4661 I2C Slave Address with the R/W bit indicating a write (‘0’).
Installation and Operation Double clicking on the MCP4661W0RD User I2CM Script will load the script details. Figure 2-14 shows what the values mean in the Script Details. These values are hex numbers. The first value (02h), is the number of bytes that will be written. The second byte (5Eh) is the MCP4661 I2C Slave Address with the R/W bit indicating a write (0).
MCP46XXEV Evaluation Board User’s Guide 2.6 MCP4661 DEMO STEPS This demo assumes that you know how to configure the PICkit Serial Analyzer for Master I2C operation. See Section 2.5 “Configuring The PICkit™ Serial Analyzer” or the “PICkit Serial Analyzer User’s Guide” (DS51647) for additional information. 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. DS51929A-page 30 Plug the PICkit serial device into the PC’s USB port.
Installation and Operation 22. On the PICkit Serial Analyzer command bar, click the Reset button. 23. Select the “MCP4661W0WR” script in the User I2CM Scripts column and then click on the Execute Script button. 24. Select the “MCP4661W0RD” script in the User I2CM Scripts column and then click on the Execute Script button. 25. Select the “MCP4661W0DEC” script in the User I2CM Scripts column and then click on the Execute Script button three times. 26.
MCP46XXEV Evaluation Board User’s Guide Device Slave Address + R/W bit FIGURE 2-15: DS51929A-page 32 Wiper 0 Data (D7:D0 = ‘FFh’) MCP46XX Write Wiper 0 Script File - Wiper Value = 0FFh. Device Slave Address + R/W bit FIGURE 2-16: Write Command to Wiper 0 Register (D8 = ‘0’) Write Command to Wiper 0 Register (D8 = ‘0’) Wiper 0 Data (D7:D0 = ‘3Fh’) MCP46XX Write Wiper 0 Script File - Wiper Value = 03Fh. © 2010 Microchip Technology Inc.
Installation and Operation 9-bit data value (07Fh) written to Wiper 0 register 9-bit data value (0FFh) written to Wiper 0 register 9-bit data value (07Fh) read from Wiper 0 register Wiper 0 register read from 9-bit data value (0FFh) 9-bit data value (03Fh) written to Wiper 0 register FIGURE 2-17: Wiper 0 register read from 9-bit data value (03Fh) MCP4661 Transaction Window - Wiper 0 Writes and Reads.
MCP46XXEV Evaluation Board User’s Guide Data value (07Fh) read from Wiper 0 register Data value (082h) read from Wiper 0 register after 3 Increment Commands FIGURE 2-19: MCP4661 Transaction Window - Wiper 0 Increments. 2.6.1 The TSSOP20EV PCB and Supported Digital Potentiometers Table 2-4 shows the current digital potentiomers that are supported by the TSSOP20EV PCB.
MCP46XXEV EVALUATION BOARD USER’S GUIDE Appendix A. Schematic and Layouts A.1 INTRODUCTION This appendix contains the schematics and layouts for the MCP46XXEV Evaluation Board. Diagrams included in this appendix: • • • • • • • A.
MCP46XXEV Evaluation Board User’s Guide BOARD – SCHEMATIC M A.3 DS51929A-page 36 Draft © 2010 Microchip Technology Inc.
Schematic and Layouts A.4 BOARD – TOP TRACE, SILK AND PADS © 2010 Microchip Technology Inc.
MCP46XXEV Evaluation Board User’s Guide A.5 BOARD – BOTTOM TRACE AND PADS DS51929A-page 38 Draft © 2010 Microchip Technology Inc.
Schematic and Layouts A.6 BOARD – LAYER 2 GROUND PLANE © 2010 Microchip Technology Inc.
MCP46XXEV Evaluation Board User’s Guide A.7 BOARD – LAYER 3 POWER PLANE DS51929A-page 40 Draft © 2010 Microchip Technology Inc.
Schematic and Layouts A.8 BOARD LAYOUT – TOP COMPONENTS © 2010 Microchip Technology Inc.
MCP46XXEV Evaluation Board User’s Guide A.9 BOARD – BOTTOM SILK, TRACE AND PADS DS51929A-page 42 Draft © 2010 Microchip Technology Inc.
MCP46XXEV EVALUATION BOARD USER’S GUIDE Appendix B. Bill of Materials (BOM) TABLE B-1: Qty BILL OF MATERIALS Reference Description Manufacturer 1 J1 CONN HEADER 6POS .100 R/A TIN 2 P9, P12 1 PCB TEST POINT PC MULTI PURPOSE THROUGH HOLE (Orange) Note 1 2 4 R14U, R15U R7D, R11U, R13D, R17U U3 1 Note 1: 2: RES 10K OHM 1/8W 5% 0805 SMD RES 0.0 OHM 1/8W 5% 0805 SMD Molex/Waldom Electronics Corp Keystone Electronics® Microchip Technology Inc.
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