19-4407; Rev 0; 1/09 MAX9939 Evaluation Kit The MAX9939 evaluation kit (EV kit) is a fully assembled and tested surface-mount PCB that evaluates the MAX9939 SPITM-programmable gain amplifier (PGA). Its internal op amp is configured as a multiple-feedback active filter by default, but can also be reconfigured so the MAX9939 operates as a differential-input, differential-output programmable gain amplifier. The EV kit features an on-board microcontroller, which receives commands from a PC through the USB port. The EV kit can be powered directly from the USB bus or from a single-supply voltage of 2.9V to 5.5V. The EV kit also includes Windows (R) 2000/XP- and Windows Vista(R)-compatible software that provides a simple user interface for exercising the MAX9939 features. The program is menu driven and offers a graphical user interface (GUI) complete with control buttons and status displays. The GUI demonstrates the programmable gains from 0.2V/V to 157V/V and the input offset voltage compensation features of the MAX9939 IC. Features o Powered Directly from a USB Port o On-Board Microcontroller to Generate SPI Commands o Easy-to-Use, Menu-Driven Software o Surface-Mount Components o Lead(Pb)-Free and RoHS Compliant o Fully Assembled and Tested Ordering Information PART TYPE MAX9939EVKIT+ EV Kit +Denotes lead(Pb)-free and RoHS compliant Component List DESIGNATION C1, C2, C4-C8, C12, C17, C19 C3 C13, C15 C9 C10, C11 QTY DESCRIPTION 10 0.1F 10%, 16V X7R ceramic capacitors (0603) Murata GRM188R71C104K TDK C1608X7R1C104K 1 4.7F 10%, 6.3V X5R ceramic capacitor (0603) Murata GRM188R60J475K TDK C1608X5R0J475K 2 10F 20%, 16V X5R ceramic capacitors (1206) Murata GRM31CR61C106M or TDK C3216X5R1C106M 1 0.033F 10%, 25V X7R ceramic capacitor (0603) Murata GRM188R71E333K TDK C1608X7R1E333K 2 22pF 5%, 50V C0G ceramic capacitors (0603) Murata GRM1885C1H220J TDK C1608C0G1H220J DESIGNATION C14 C16, C18 C20 C21 QTY DESCRIPTION 1 1F 10%, 16V X5R ceramic capacitor (0603) Murata GRM188R61C105K TDK C1608X5R1C105K 2 10pF 5%, 50V C0G ceramic capacitors (0603) Murata GRM1885C1H100J TDK C1608C0G1H100J 1 4700pF 10%, 50V X7R ceramic capacitor (0603) Murata GRM188R71H472K TDK C1608X7R1H472K 1 220pF 10%, 50V X7R ceramic capacitor (0603) Murata GRM188R71H221K TDK C1608X7R1H221K C22 0 Not installed, capacitor (0603) D1 1 Green LED (0805) FB1 1 70, 4A ferrite bead (0603) TDK MMZ1608R301A Murata BLM18SG700 TN1 SPI is a trademark of Motorola, Inc. Windows and Windows Vista are registered trademarks of Microsoft Corp. ________________________________________________________________ Maxim Integrated Products For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim's website at www.maxim-ic.com. 1 Evaluates: MAX9939 General Description MAX9939 Evaluation Kit Evaluates: MAX9939 Component List (continued) DESIGNATION DESIGNATION QTY DESCRIPTION H1 0 Not installed, 2 x 5-pin JTAG header H2 0 Not installed, 2 x 6-pin JTAG header IN_DIFF, OUT_DIFF 2 75 BNC PCB-mount connectors JU1 1 3-pin header P1 1 USB type-B right-angle PC-mount receptacle R1, R2 2 27 5% resistors (0603) R3 1 1.5k 5% resistor (0603) R4, R7 2 470 5% resistors (0603) R5 1 2.2k 5% resistor (0603) R6 1 10k 5% resistor (0603) R8, R17, R24, R25 4 0 resistors (0603) R9, R10, R11, R22, R23 0 Not installed, resistors (0603) R12-R16 0 Not installed, resistors--short PC trace (0603) R18, R19 2 66.5k 1% resistors (0603) R20 1 121k 1% resistor (0603) R21 1 1.21k 1% resistor (0603) QTY DESCRIPTION U1 1 SPI programmable gain amplifier (10 MAX(R)) Maxim MAX9939AUB+ U2 1 Low-voltage level translator (14 TSSOP) Maxim MAX3390EEUD+ U3 1 Low-power 16-bit microcontroller (68 QFN-EP*) Maxim MAXQ2000-RAX+ U4 1 LDO regulator (5 SO70) Maxim MAX8511EXK25+ U5 1 UART-to-USB converter (32 TQFP) FTDI FT232BL U6 1 93C46 3-wire 16-bit EEPROM (8 SO) Atmel AT93C46A-10SU-2.7 Y1 1 16MHz crystal Y3 1 6MHz crystal -- 1 Shunt -- 1 PCB: MAX9939 Evaluation Kit+ *EP = Exposed pad. Component Suppliers SUPPLIER PHONE WEBSITE Murata Manufacturing Co., Ltd. 770-436-1300 www.murata.com TDK Corp. 847-803-6100 www.component.tdk.com Note: Indicate that you are using the MAX9939 when contacting these component suppliers. MAX9939 EV Kit Files PART DESCRIPTION INSTALL.EXE Installs the EV kit files on your computer MAX9939.EXE Application program FTD2XX.INF USB device driver file UNINST.INI Uninstalls the EV kit software USB_Driver_Help.PDF USB driver installation help file MAX is a registered trademark of Maxim Integrated Products, Inc. 2 _______________________________________________________________________________________ MAX9939 Evaluation Kit Recommended Equipment Before beginning, the following equipment is needed: * A user-supplied Windows 2000/XP/Vista-compatible PC with a spare USB port * Signal generator * Oscilloscope Note: In the following sections, software-related items are identified by bolding. Text in bold refers to items directly from the EV kit software. Text in bold and underlined refers to items from the Windows operating system. Procedure The MAX9939 EV kit is fully assembled and tested. Follow the steps below to verify board operation. Caution: Do not turn on power supplies until all connections are completed. 1) Visit www.maxim-ic.com/evkitsoftware to download the latest version of the EV kit software, 9939Rxx.ZIP. Save the EV kit software to a temporary folder and uncompress the ZIP file. 2) Install the EV kit software on your computer by running the INSTALL.EXE program inside the temporary folder. The program files are copied and icons are created in the Windows Start | Programs menu. 3) Verify that a shunt is installed across pins 2-3 of jumper JU1 (USB powered). ument included with the software for additional information. 6) Start the EV kit software by opening its icon in the Start | Programs menu. The EV kit software main window appears, as shown in Figure 1. Observe as the program automatically detects the MAX9939 EV kit and starts the main program. 7) Set the signal generator to produce an output signal of 25mV peak-to-peak at a frequency of 1kHz. 8) Connect the signal generator to the IN_DIFF BNC connector. 9) Connect the oscilloscope to the OUT_DIFF BNC connector. 10) Enable the signal generator. 11) Adjust the gain and offset settings using the provided software. See the Detailed Description of Software section to evaluate the features of the EV kit. 12) Monitor and verify the output with the oscilloscope. Detailed Description of Software The MAX9939 EV kit software GUI (Figure 1) is a Windows program that provides a convenient means to control the MAX9939. By updating the Gain/Offset Setting group box or Shutdown checkbox, the correct SPI-compatible write operation is generated to update the internal registers of the MAX9939. Note, updating only the select radio group does not modify the internal registers. 4) Connect the USB cable from the PC to the EV kit board. A New Hardware Found window pops up when installing the USB driver for the first time. If a window that is similar to the one described above is not seen after 30s, remove the USB cable from the board and reconnect it. Administrator privileges are required to install the USB device driver on Windows. 5) Follow the directions of the Add New Hardware Wizard to install the USB device driver. Choose the Search for the best driver for your device option. Specify the location of the device driver to be C:\Program Files\MAX9939 (default installation directory) using the Browse button. During device driver installation, Windows may show a warning message indicating that the device driver Maxim uses does not contain a digital signature. This is not an error condition and it is safe to proceed with installation. Refer to the USB_Driver_Help.PDF doc- Figure 1. MAX9939 EV Kit Software Main Window Select The Select radio group of the MAX9939 EV kit GUI controls the SEL bit to select which internal register is written to. Select Gain to write to the gain register or select Offset to write to the input offset voltage trim register. _______________________________________________________________________________________ 3 Evaluates: MAX9939 Quick Start Evaluates: MAX9939 MAX9939 Evaluation Kit Programming Gain and Input Offset Voltage The Gain/Offset Setting group box of the MAX9939 EV kit software controls the data written to the two internal registers of the MAX9939 IC. The Gain Selection dropdown list writes to the gain register to set the gain of the amplifier. The Input Offset(mV) drop-down list writes to the input offset voltage (VOS) register to cancel the inherent offset voltage of the amplifier. Refer to Tables 3 and 4 in the MAX9939 IC data sheet for gain and input offset voltage settings. Shutdown The Shutdown checkbox of the MAX9939 EV kit GUI allows the user to place the device in a low-power shut- down mode with only the digital part of the chip staying active. Leave the Shutdown checkbox unchecked for normal circuit operation. General-Purpose 3-Wire (SPI) Interface Utility The general-purpose 3-wire interface utility (Figure 2) can also be used to communicate with the MAX9939 using low-level SPI commands. Select the Options | Interface menu item and select the 3-wire interface tab to access the utility. The utility configures the 3-wire serial-interface parameters, such as MSB position, CPOL, CPHA, MOSI/MISO inverted logic, CS active state (high or low), SPI clock (SCLK) speed, and custom selection of SPI signal pins. The data to be sent is Figure 2. MAX9939 Interface Diagnostic Window 4 _______________________________________________________________________________________ MAX9939 Evaluation Kit Detailed Description of Hardware Power Input The MAX9939 EV kit operates from a single supply VCC between 2.9V to 5.5V. Using 3-pin jumper JU1, the EV kit can be powered through the host PC's USB port or by an external power supply. By default, a shunt is installed across pins 2-3 and the USB provides 5V (+5VUSB) to power the EV kit. Install a shunt across pins 1-2 to use an external power supply applied at the VCC pad. Table 1 lists the selectable jumper options. Table 1. Jumper JU1 Functions (VCC) SHUNT POSITION Evaluating the EV Kit as a DifferentialInput, Differential-Output PGA The MAX9939 EV kit can also be evaluated as a differential-input, differential-output programmable gain amplifier by configuring the output stage as follows: 1) Remove R24, R25, C20, and C21. 2) Replace R20 with a 0 resistor. VCC DESCRIPTION 1-2 EV kit requires an external power supply applied at the VCC pad 2-3* EV kit is powered through the host PC's USB port (+5VUSB) *Default position. Default Configuration as an Active Filter The MAX9939 EV kit comes standard with the MAX9939 configured as an anti-aliasing filter to provide a cutoff frequency to maximize the Nyquist bandwidth of an ADC. The external resistors and capacitors are chosen to create a 1.3kHz lowpass, 3rd-order, 0.1dB Chebyshev multiple-feedback active filter. Refer to the Applications Information section in the MAX9939 IC data sheet for a more detailed description of using the MAX9939 IC as an active filter. 3) Replace R18 and R19 with 10k resistors. 4) If an anti-aliasing filter is required, replace C2, C22 and R21, R22 capacitor/resistor values as required. If an anti-aliasing filter is not required, replace R21 and R22 with 0 resistors while leaving C2 and C22 open. 5) Utilize the OUT_DIFF BNC connector to analyze the differential output. Caution: Ensure that pin 2 of the IN_DIFF BNC connector and pin 2 of the OUT_DIFF BNC connector are isolated from each other (i.e., not shorted together). _______________________________________________________________________________________ 5 Evaluates: MAX9939 8-bit data represented by a two-digit hexadecimal code. The code is entered in the Data bytes to be written edit box and transmitted by pressing the Send Now button. Evaluates: MAX9939 MAX9939 Evaluation Kit Figure 3a. MAX9939 EV Kit Schematic (Sheet 1 of 3) 6 _______________________________________________________________________________________ MAX9939 Evaluation Kit Evaluates: MAX9939 Figure 3b. MAX9939 EV Kit Schematic (Sheet 2 of 3) _______________________________________________________________________________________ 7 Evaluates: MAX9939 MAX9939 Evaluation Kit Figure 3c. MAX9939 EV Kit Schematic (Sheet 3 of 3) 8 _______________________________________________________________________________________ MAX9939 Evaluation Kit Evaluates: MAX9939 Figure 4. MAX9939 EV Kit Component Placement Guide--Component Side _______________________________________________________________________________________ 9 Evaluates: MAX9939 MAX9939 Evaluation Kit Figure 5. MAX9939 EV Kit Component PCB Layout--Component Side 10 ______________________________________________________________________________________ MAX9939 Evaluation Kit Evaluates: MAX9939 Figure 6. MAX9939 EV Kit PCB Layout--Solder Side Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________ 11 (c) 2009 Maxim Integrated Products is a registered trademark of Maxim Integrated Products, Inc. Mouser Electronics Authorized Distributor Click to View Pricing, Inventory, Delivery & Lifecycle Information: Maxim Integrated: MAX9939EVKIT+