Application Note 1800 ISL26104AV28EV1Z Evaluation Board User Guide General Description Key Features The ISL26104AV28EV1ZA provides a means to evaluate the functionality and performance of the ISL26104 A/D converter. * ADC is galvanically-isolated from USB connection The board includes an AT90USB162 microcontroller with a USB interface. The microcontroller interfaces to the ISL26104 ADC via a galvanically-isolated interface and provides serial communication via USB between the board and the PC. * On-board voltage reference Software for the PC provides a GUI (graphical user interface) that allows the user to configure the ISL26104 device and to perform data capture, and to then process and plot the results in the time domain, as a histogram, and/or to perform frequency domain analysis on the captured data. The GUI also enables the user to save conversion data from the ADC to a file, or to save the results of the analyzed conversion data. * On-board microcontroller * Evaluation software - Time domain analysis - Noise histogram analysis - FFT analysis Ordering Information PART NUMBER ISL26104AV28EV1Z PACKAGE (Pb-free) Evaluation Board FIGURE 1. EVALUATION BOARD FOR THE ISL26104 December 18, 2012 AN1800.0 1 CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. Copyright Intersil Americas Inc. 2012. All Rights Reserved. 1-888-INTERSIL or 1-888-468-3774 | Intersil (and design) is a trademark owned by Intersil Corporation or one of its subsidiaries. All other trademarks mentioned are the property of their respective owners. Application Note 1800 Hardware Evaluation Board Overview The ISL26104AV28EV1Z evaluation board provides the user a means of evaluating the ISL26104 Analog-to-Digital Converter (ADC). The ISL26104 is a high performance 24-bit ADC that includes a very low noise programmable gain amplifier. The ISL26104 offers multiple gain selections: 1x, 2x, 4x, 8x, 16x, 32x, 64x and 128x. It offers 20 word rate selections from 2.5Sps to 4000Sps (clock = 4.9152 MHz). Gain and word rate selections are made by writing into on-chip registers. The ISL26104AV28EV1ZA evaluation board is segmented into two sections. These sections are galvanically-isolated with a multi-channel isolation chip. The two different sections of the board can be readily identified in Figure 1, which shows an image of the board. The ISL26104 ADC and its associated circuitry (voltage reference and input signal components) are on the left side of the image. The ADC and its associated circuitry are powered by a laboratory supply. The microcontroller with its USB interface is on the right side of the image in Figure 1. This circuitry is powered from the USB connection. See Figure 2 for a block diagram of the circuitry. The microcontroller provides the USB interface to the PC. A software GUI is available to communicate with the microcontroller and provides the means to collect and analyze data from the ADC. The board comes with an ISL26104 soldered in place. This can be removed and an ISL26102 soldered in its place if desired. FIGURE 2. BLOCK DIAGRAM OF THE EVALUATION BOARD FOR THE ISL26104 2 AN1800.0 December 18, 2012 Application Note 1800 Galvanic Isolation Galvanic isolation is not necessary in every application. The purpose of the isolation on the evaluation board is to prevent noise from the USB ground connection from affecting the sensitive measurements made by the ADC when used in the 64X or 128X gain settings. The ground connection of the USB cable in most computers is referenced directly to the power supply ground of the computer. This ground can be especially noisy in notebook PCs powered from an external power module. Operating the ADC on a power system that is galvanically isolated from the USB ground ensures that the performance of the ADC on the evaluation board will not be affected by ground noise from the PC being used to collect data from the board. ADC Section The ADC section of the evaluation board has three banana jack power connections that enable this portion of the board to be powered from a low noise laboratory supply. The banana jack labeled AGND serves as the power supply ground connection for the ADC segment of the board. The DVDD jack supplies the digital portion of the ADC (3.3V to 5V) and the section of the galvanic isolation chip that interfaces to the ADC. The AVDD jack supplies the analog portion of the ADC and the voltage reference. The voltage reference used in the ADC circuitry is an Intersil ISL21009BFZ25 2.5V reference. A header is provided to also allow the use of an external voltage reference for the ADC. The ADC portion of the circuitry on the board is illustrated in Figure 3. The ISL26104 offers several sample rate, gain, and input channel options. These options are selected using on-chip registers that can be written by the PC GUI software. When a command to change the gain, the rate, or the multiplexer channel is issued by the GUI, the command is sent over the USB connection to the microcontroller on the evaluation board. The microcontroller then writes into the proper ADC register via the serial port using the CS/, SDI, SDO/RDY and SCLK signals which are connected to the ADC from the C through the isolation chip as shown in Figure 4. FIGURE 3. ISL26104 ANALOG-TO-DIGITAL CONVERTER 3 AN1800.0 December 18, 2012 Application Note 1800 SDI SCLK CS SDO/RDY FIGURE 4. GALVANIC ISOLATOR CHIP 4 AN1800.0 December 18, 2012 Application Note 1800 The ADC uses a 4.9152MHz crystal operating with an on-chip amplifier for its clock source. This can be disconnected and an external clock can be sourced to drive the clock input to the chip. Alternately, the XTALIN/CLOCK pin can be grounded and the ADC will operate from an on-chip RC type oscillator. connected to input terminals on the board (VREF+ and VREF-) and selected through jumpers on headers J25 and J26 to provide a reference voltage for the ADC as shown in Figure 6. These headers also provide the option of selecting AVDD and AGND as inputs to the VREF+ and VREF- on the ADC. The board provides a 2.5V reference IC as the voltage reference for the ADC, as shown in Figure 5 or, an external voltage can be FIGURE 5. 2.5V REFERENCE FIGURE 6. VOLTAGE REFERENCE SELECTION OPTIONS 5 AN1800.0 December 18, 2012 Application Note 1800 The evaluation board provides separate terminal connections for each of the differential signals into the ADC. These terminals are in shown in Figure 7. Be attentive of the labeling of the connections and their polarities when connecting external signals. The channel numbers on the terminal blocks are not in numeric order and some have their polarities labeled opposite of others. FIGURE 7. ANALOG INPUTS FIGURE 8. COMMON MODE SELECTIONS 6 AN1800.0 December 18, 2012 Application Note 1800 Header connector J17 in Figure 8 allows the user to select one of the following options for the common mode bias (CMB) voltage: the 2.5V voltage reference output, ground (AGND), a voltage generated by a resistor divider (RDIV) that divides the AVDD supply using two 1k resistors, or a voltage determined by the user which must be connected to the hole next to the header connection labeled FLT (Floating Input). The voltage source which is selected by header J17 is provided to the analog input channels as a common mode bias voltage (CMB). Each of the input channels has jumpers (for example, J9 and J10 for input AIN1 in Figure 7) to allow the user to connect the common mode bias (CMB) voltage to either the AIN+ or the AINinput of the channel. This enables the external signal source to be biased to a common mode value supplied by the board. If both jumpers are put in place, and the analog inputs to the terminals are left disconnected, the inputs to this particular AIN channel of the ADC will be shorted to the common mode voltage. This provides a means for testing the noise performance of the ADC with both of its inputs (AIN+ and AIN-) shorted to a common mode voltage. The ADC interfaces to the microcontroller through the galvanic isolators. The ADC side of the isolator chip is powered by the same supply that powers the DVDD supply of the ADC. The Microcontroller Section Figure 9 illustrates the microcontroller circuitry. There is a reset button provided but it is seldom necessary to use it. The microcontroller has its own power-on reset which will initialize the microcontroller when the USB interface is connected to a powered PC. Power for the microcontroller section comes from the USB interface. The microcontroller circuit includes a DIP switch, some LEDs and two header connectors. The board is shipped from the factory with the four switches of the DIP switch set to the OFF position. This is required for normal operation. Other switch positions are used at the factory to troubleshoot the isolator interface if the board is not functioning properly. These switch positions are not useful for normal board application, therefore all the switches should be kept in the OFF position. The three LEDs will illuminate when the USB interface is plugged in and actively powered. Some of the LEDs blink when the microcontroller is passing a command to the ADC or when data is being collected from the ADC. The microcontroller section includes two headers. Header J1 is a six pin connection used to program the flash in the microcontroller. Header J22 provides access to the four signals that are used by the microcontroller to interface to the ADC. If desired, the customer could remove the isolator chip from the board and use header J22 to connect into his own circuitry to his ADC. This enables the customer to use the PC GUI software to evaluate the ADC in the customer's system. An alternate method of connection is to remove the ISL26104 device from the board and connect into the customer circuit via the signals on header J20. If this method is chosen, the customer would need to power the ADC side of the isolator chip from his system (3V to 5V). The microcontroller communicates with the ADC via the galvanic isolator chip. The microcontroller side of the isolator is powered by the voltage from the USB connection. FIGURE 9. MICROCONTROLLER WITH USB INTERFACE 7 AN1800.0 December 18, 2012 Application Note 1800 Note on Power Supply Sequencing See "Appendix #1 How to Obtain and Install the GUI Software" on page 19 to obtain the internet link to download the GUI software. There are two galvanically isolated sections to the board. The ADC portion is powered by a laboratory supply. The microcontroller section is powered by the USB connection. Proper voltages from an external supply must be provided to the DVDD (3.3V to 5V), AVDD (5V) and the AGND banana plug connectors for the ADC portion of the board to function. LEDs, as shown in Figure 3, will be illuminated by DVDD and AVDD when they are powered. Note that these supplies, AVDD and DVDD, can be applied and removed in any sequence without regard to each other or with regard to whether the USB interface is connected and powered or not. The USB interface can also be disconnected and reconnected without consequence with regard to whether the power supply to the ADC section of the board is powered or not. In other words, there is no power supply sequencing requirement for any of the supplies to the board, whether it be from the laboratory supply powering the ADC section, or whether it be the microcontroller section powered from the USB connection. Software The evaluation board has GUI software available that runs on the PC. The software is designed to operate under Windows XP or later. Once the PC GUI software is copied onto the PC, click on the setup.exe file and follow the on screen instructions to load the software. Note that the software uses the USB interface to communicate with the evaluation board. The software uses the USB HID driver that is part of the Windows operating system so it is not necessary to load any other drivers for the USB interface. Running the GUI Before starting the GUI software the evaluation board should be connected to the PC by means of a USB cable With the board connected via USB, run the GUI program by selecting Start ->All Programs->ISL261XX->ISL26XX Evaluation Software. If the software is started before the connection to the board is made, the GUI will indicate that the USB interface is not connected with the message: USB Status: Not Connected as shown in Figure 10. If this occurs, connect the evaluation board to the PC with the USB cable. The USB status should change to Connected as shown in Figure 11. FIGURE 10. FIGURE 11. 8 AN1800.0 December 18, 2012 Application Note 1800 The screen shows File, which is a pull down menu, and four different window tabs, Configuration, Time Domain, Histogram, and Frequency Domain. With the screen shown as in Figure 12, the software has the Configuration window as the currently active window. The first step of configuration is to select the appropriate part number that represents the evaluation board to be tested using the Device Selection window. Associated with the Device Selection window is a pull down menu with various part numbers as shown in Figure 12. The ISL26104 option should be selected and the Initialize button clicked to configure the GUI software to operate with this particular evaluation board. Before the Initialize button is clicked, the ADC section of the board should be powered by the laboratory power supply if the GUI software is to communicate properly with the ISL26104. Once the Initialize button is clicked with the ISL26104 selection, the screen will change and illustrate a block diagram of the ISL26104 ADC with windows inside the block diagram to select various options, such as the Input Mux channel and the Gain options available in the ADC as shown in Figure 13. The ISL26104 device uses on-chip registers as the means for it to be configured. The user of the GUI software can use the Configuration window to set up the various options in the ISL26104 device. Some of these options are (1) Input channel (Input Mux) selection, (2) Sample Rate selection, and (3) Gain selection. The ISL26104 allows the user to configure the various settings for the ISL26104 via the Configuration window of the GUI as shown in Figure 13. The Sample Rate can be set by using the Sample Rate pull down menu as shown in Figure 14. Sample rates from 2.5 to 4000 samples per second can be selected. The Input Mux can be changed via a pull down menu as shown in Figure 15. The Gain can be changed via a pull down menu as shown in Figure 16. Any time a menu option is changed the Write Values button should be clicked. This instructs the GUI software to send a command to the chip to change the appropriate on-chip register. Note that multiple items (Sample Rate, Input Mux, Gain, etc.) can be changed and the Write Values button need only be clicked once for all the selections to be sent to the evaluation board. FIGURE 12. FIGURE 13. 9 AN1800.0 December 18, 2012 Application Note 1800 FIGURE 14. FIGURE 15. 10 AN1800.0 December 18, 2012 Application Note 1800 FIGURE 16. Offset calibration can be performed by clicking the Offset Calibration button. This issues a command for the ISL26104 to execute its offset calibration operation. If offset calibration is performed, the value of the on-chip offset registers will be displayed in the O/S window in the lower left portion of the block diagram of the chip shown in the Configuration window. Note that there are three 8-bit offset registers (high, mid and low) inside the ISL26104 which make up the entire 24-bit offset value. The decimal value of this 24-bit word is what is displayed in the O/S window as shown in Figure 17. 11 AN1800.0 December 18, 2012 Application Note 1800 FIGURE 17. typed as a hex value) into the Address window and the click the SPI RD button, the value '7' will be returned and displayed in the Data window. Hex '7' indicates that the binary value in the register was set to '00000111', gain = 128. Signal Processing Windows FIGURE 18. From the Configuration window one can see three other Window selection options: Time Domain, Histogram, and Frequency Domain. These window selection options are seen in Figure 19. At the bottom of the configuration window, there is an SPI Communications window as depicted in Figure 18. After writing Hex values into the Address text box and into the Data text box the user can then click the SPI WR button to write an 8-bit value into the on-chip register associated with that address. Or, if the Data text window is empty and a Hex value is entered into the Address window, the SPI RD button can be clicked. This will cause the 8-bit value of the selected register to be read from the chip and written into the Data text window. For example, if the user selects '128' in the Gain pull down menu and then clicks the Write Values button, this will set the gain register in the chip for a gain of 128X. One can then use the SPI Comm feature to read the register back. Enter 17 [this is the address to read the on-chip gain register] (do not enter the letter h or H as the text window will automatically interpret what is 12 FIGURE 19. Each of these windows will be discussed in the following sections in detail. All three allow the user to collect and process data from the ADC on the evaluation board. Time Domain Window The Time Domain window allows the user to collect samples from the ADC on the evaluation board and display them in the time domain. The number of samples is initially defaulted to 64, but can be set in a pull down window from 1 to 1048576 (220). If a large number of samples is requested on an ADC with a slow AN1800.0 December 18, 2012 Application Note 1800 sample rate, one should be aware of the amount of time required for data collection. When the Acquire button is clicked, the samples will be collected and transferred to the PC. The main graphing window can graph up to 256 samples. If more than 256 samples are collected, the time plot of the entire sample set can be displayed by clicking on the Pop Out button. Figures 20 and 21 illustrate the capture of 4096 samples. The window in Figure 20 displays only the first 256 samples. Figure 21 illustrates the results when the Pop Out button has been selected. Buttons at the top of the plot provide several user graph tool functions as follows: FIGURE 22. The button options shown in Figure 22 are also available in the Histogram and Frequency Domain windows. House: Zooms to the original zoom scale factor. Left/Right: Goes back/forward 1 zoom command. So if you zoom in twice and want to go back to the first zoom, you'd click the left arrow. Four Points: Moves the axes around. Magnifying Glass: Zoom box. Scaling Icon (Up/down/left/right): Changes the size of the plot in the window. You can scale the graph as large as the border. Check Box (customize): Allows customization of axis labels/plot title as shown in the Figure 23. Disk (Save): Saves the plot as an image. When selected, a window will open that offers several image format options. FIGURE 20. Once the data from the ADC has been captured, it can be saved to a file. The histogram and the spectrum analysis can also be saved. See "Appendix #2 Data File Formats" on page 19 for a discussion of the formats of the saved files. Note that the raw data (conversion words from the ADC) files can also be read back into the GUI once saved. Or data collected from another source can be read into the GUI software for analysis if the proper data format is used. See "Appendix #2 Data File Formats" on page 19 for details. FIGURE 21. 13 AN1800.0 December 18, 2012 Application Note 1800 FIGURE 23. File Operations If the File label is clicked with the user's mouse, a menu list is shown as in Figure 24. FIGURE 24. 14 AN1800.0 December 18, 2012 Application Note 1800 The About selection will be discussed first. When the GUI is first started it sends a command to the evaluation board and tells the microcontroller to send back the version number of the firmware code that is in the microcontroller. If File => About is selected, the GUI will open a window that indicates the version number of the microcontroller firmware, and the GUI software version as shown in Figure 25. Click the OK button to close the window. FIGURE 25. The File =>Exit selection is a means to exit and close the GUI program. The File =>Save selection is meaningful only after data has been collected using the functions on the Time Domain, Histogram, or Frequency Domain windows. Figure 26 shows that the options under the File => Save selection are Raw Data (text), Histogram Data (text), Spectrum Data (text), All Data (Excel), and Configuration. These options allow the user to save data to a file. The file formats for each of the options are discussed in "Appendix #2 Data File Formats" on page 19. Note that the Excel format is for Excel 2003 and supports only 65k cells, which limits the number of samples that can be saved in this format. The File =>Load Data option allows the user to read back into the GUI raw data (conversion words for the ADC) once saved or, data collected from another source can be read into the GUI software for analysis if the proper data format is used. See "Appendix #2 Data File Formats" on page 19 for more information. The File =>Configuration option allows the user to save the register configuration of the ADC that is being used to collect data. See "Appendix #2 Data File Formats" on page 19 for an example configuration file format. FIGURE 26. 15 AN1800.0 December 18, 2012 Application Note 1800 Histogram Window If one clicks on the histogram window after collecting data using the Time Domain window the histogram of the time domain data will be plotted. Alternatively, the Histogram window provides the user options to set the number of samples to be collected and to acquire a new sample set based upon this selection. The Bin Width window allows the user to set the number of converter codes that are counted in one bin of the histogram. This number is defaulted to "1". When the histogram is plotted, the plot includes markers for the mean value (red vertical line) and for one standard deviation from the mean on each side (green dashed lines). Signal statistics are listed in the plot itself and in the text boxes below the graph as shown in Figure 27. The Pop Out button shows the graph without the statistics listed. FIGURE 27. 16 AN1800.0 December 18, 2012 Application Note 1800 Frequency Domain Window If the user has collected data in either the Time Domain window or the Histogram window, and then clicks on the Frequency Domain menu option, the data will be processed with the FFT algorithm and the resulting spectral information will be displayed, as shown in Figure 28. The red lines mark harmonics. If no signal is present, the software assumes the highest point in the spectrum is the fundamental. If the log(freq) check box is checked, the spectral plot will be graphed with the frequency axis on a Log scale, as shown in Figure29. If the Grounded Input Test check box is checked, and data is collected with the input of the converter shorted, the GUI software will calculate the various parameters such as SNR (signal to noise ratio) by computing the ration of an artificial full scale sine wave to the total noise in the bandwidth. The Grounded Input Test check box should only be checked if there is no actual signal input into the converter (The board provides a means to short both differential inputs to an ADC channel to a common mode voltage for this test). Note that if the Grounded Input Test check box is not checked, the software will compute parameters such as SNR, by calculating the ratio of the largest magnitude component in the spectrum (other than the DC offset) to the noise. FIGURE 29. FIGURE 30. FIGURE 28. FIGURE 31. 17 AN1800.0 December 18, 2012 Application Note 1800 There are several different selectable options in the Frequency Domain window. The number of samples can be set up to 1048576 (220) using a pull down menu as shown in Figure 30. Note that the frequency domain software (FFT computation) must have at least 1024 samples to compute a proper spectral plot. The software allows a number of different window functions to be used. The different windowing options can be selected in the Windowing menu as shown in Figure 31. These are normally used when testing is performed with a sine wave as the input signal. This same software GUI supports other ADC platforms (higher speed SAR ADCs) where these windowing options are more commonly used. Figure 32 illustrates the spectral plot of one data set of 4096 samples. For this data collection, the ADC had its gain set to 1X and its sample rate set to 1000Sps. The results of the FFT can be averaged by setting the Mode radio button to Ave. and then using the window next to the Ave. button to set the number of data sets to be averaged. When averaging is performed, the output results of many FFTs are averaged and are used to produce a spectral plot with a smoothed (averaged) spectrum as shown in Figure 33. Recall that the spectrum plot data can be saved by clicking on the File=>Save=>Spectrum Data option at the top of the window. FIGURE 33. FIGURE 32. 18 AN1800.0 December 18, 2012 Application Note 1800 Appendix #1 How to Obtain and Install the GUI Software The following is the address for the ISL26104 product page on the Intersil web site. http://www.intersil.com/products/ISL26104 Go to this link and find the "Documents" tab. The PC GUI software installer can be downloaded from this location. Note that the software installer does have a license agreement that will be presented when the software is loaded onto your PC. Appendix #2 Data File Formats The GUI software allows the user to save data from the time domain (raw data), data from the histogram processing, and data from the spectrum processing segments of the software. It also allows raw data (time domain data) files to be read back into the GUI if they have the proper header and format. Raw Data As an example, a time domain collection of only 8 samples has been collected and saved to a file. The content of the file that is saved has the following format: ISL26104 10.0 24 8 214 226 241 234 219 213 224 224 The file has a header that consists of the part number (ISL26104), the sample rate (10), the number of bits in the conversion word (24), and the number of samples in the file (8). The header is followed by the 8 conversions words in signed decimal format. Histogram Data A data collection of 1024 data words was collected and the histogram performed. The histogram data was then saved into a file. The content of the file has the following format. The histogram statistics are listed first, followed by the converter codes and their respective histogram counts. Signal Statistics Min: 23 Max: 35 Range: 13 Mean: 29.356 StDv: 1.976 19 Code 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 Hits 0 0 1 2 8 58 103 179 229 164 129 89 34 21 7 0 Spectrum Data A data set of 1024 points was collected at a sample rate of 100Sps. The FFT output will produce a spectrum plot with 512 Bins of magnitude data. Only the beginning and ending portion of the data file has been reproduced here to save space. Note that the Bins start at 0 frequency and increase to one half the sample rate (50Hz). Note that the magnitude in dB is the magnitude of the noise in dB below full scale rms but it is scaled based upon magnitude/BIN, not magnitude/Hz. Freq Magnitude(dB) 0.0 127.490860112 0.09765625 130.138393031 0.1953125 139.550586747 0.29296875 132.866111959 0.390625 127.884217984 0.48828125 126.538951953 0.5859375 126.769048076 0.68359375 131.31820625 0.78125 149.352655015 0.87890625 134.478247602 0.9765625 139.032099632 1.07421875 133.269604586 XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 48.92578125 144.77615475 49.0234375 154.371891495 49.12109375 142.708481612 49.21875 138.531922503 49.31640625 138.378824752 49.4140625 142.563086329 49.51171875 158.690364592 49.609375 144.250894284 49.70703125 142.996812327 49.8046875 144.030316874 49.8046875 144.707081022 AN1800.0 December 18, 2012 Application Note 1800 FIGURE 28. 34. Excel Data Format Load Data Function If the File=>Save=>Excel option is used, the Time Domain, Histogram and Frequency Domain data will be saved into an Excel file with each of the three data sets on a different sheets as shown in Figure 34. The GUI allows raw (time domain) data to be loaded back into the GUI. Alternately, the user might collect data in another system and import the conversion word data into the GUI to perform analysis. To be able to read the data the file must have the proper header (as discussed previously in the "Raw Data" on page 19 of this appendix). Note that the Excel format is for Excel 2003 and supports only 65k cells which limits the number of samples that can be saved in this format. Configuration Data TABLE 1. ISL26104 REG. NAME REG. ADDR REG VALUE (HEX) Word Rate 0x85 0xb Input Mux 0x87 0x0 Channel Ptr 0x88 0x0 PGA Gain 0x97 0x0 Delay Timer 0xc2 0x0 20 The header must have a header with a part number (this can be something other than a chip number), sample rate, number of bits in the converter, and the number of samples, followed by the data in decimal format. The largest value of any reading cannot exceed one half 2(number of bits in the converter). For example, if the number of bits in the converter is 12, then the largest reading can be no greater than (212)/2 or 2048. AN1800.0 December 18, 2012 Application Note 1800 Appendix #4 Evaluation Board Factory Jumper Settings ISL26104 > part number 100.0 > sample rate 24 > number of bits in the converter 8 > number of data samples in the file 394 >conversion data in signed decimal format 361 405 411 397 416 423 416 Figure 35 indicates the position of the header shunts when the board is shipped from the factory. Header J17 is connected with the 2.5V reference selected as the common mode voltage. Headers J9 and J10 are shorted with shunts to connect the common mode voltage to the AIN1+ and AIN1- signals coming from the terminal block connector. This effectively shorts both inputs to Channel 1 on the ADC to the common mode voltage and enables the ADC to be tested with a shorted input. One or both of these jumpers must be removed if the ADC is to measure a signal on this channel. Appendix #3 USB VID and PID The VID (vendor ID) for Intersil = 09AA) and PID (product ID) = 201C for the evaluation board can be found by examining the Windows Systems Information under Components => USB. It will be listed as a HID Compliant device with the VID and PID indicated as follows: Headers J25 and J26: the 2.5V_VREF option is selected on J25. The AGND option is selected on J26. These enable the 2.5V voltage reference chip to be the voltage reference for the ADC. DIP switch: Switches S2-1, S2-2, S2-3 and S2-4 must be positioned in the off position. If the switches are positioned with any switch in the closed (ON) position, the microcontroller will be put into a factory test mode, or into a non-functional state. If the microcontroller is in either of these states, it will not communicate properly with the PC software GUI. FIGURE 35. 21 AN1800.0 December 18, 2012 Application Note 1800 Appendix #5 Evaluation Board Layout and Component Placement FIGURE 36. FIGURE 37. Intersil Corporation reserves the right to make changes in circuit design, software and/or specifications at any time without notice. Accordingly, the reader is cautioned to verify that the Application Note or Technical Brief is current before proceeding. For information regarding Intersil Corporation and its products, see www.intersil.com 22 AN1800.0 December 18, 2012 ISL26104AV28EV1Z Schematics AVDD J25 HDR3X2 AVDD 1 2 VREF+ 3 4 2.5V 5 6 AIN1+ C3 X7R 0.01uF 2 AIN1+ AIN1- 1 J9 HDR2X1 C2 X7R 4700pF J8 CMB AGND R12 10 VREF+ 2.5V_VREF 2 VREF+ VREF- 23 J10 HDR2X1 C27 X7R 0.1uF 1 J24 AIN1C4 X7R 0.01uF GND VREFGND J26 HDR3X2 1 2 3 4 5 6 R13 C29 NO-POP 47uF 10 VREF- AGND AGND AVDD AIN3+ 1 C14 X7R 4700pF J14 Application Note 1800 C15 X7R 0.01uF 2 AIN3+ AIN3- J15 HDR2X1 CMB AGND J16 HDR2X1 AIN3- AGND C16 X7R 0.01uF C19 X7R 1uF U6 1 GND_OR_NC 2 VIN 3 DNC 4 GND 8 DNC 7 DNC 6 VOUT 5 TRIM 2.5V_VREF C21 X7R 0.1uF ISL21009BFB825 2.500V AGND AGND AGND AIN4- AIN4AIN4+ C18 X7R 0.01uF 2 J5 HDR2X1 C17 X7R 4700pF 1 J2 CMB AGND J6 HDR2X1 AVDD AIN4+ C1 X7R 0.01uF AGND CMB AIN2C7 X7R 0.01uF 2 AIN2AIN2+ 1 J11 J12 HDR2X1 C5 X7R 4700pF J17 HDR4X2 1 2 3 4 5 6 7 8 R19 1K 2.5V GND RVIV 2.5V_VREF FLT R20 1K CMB AGND AGND J13 HDR2X1 AIN2+ AGND C9 X7R 0.01uF AN1800.0 December 18, 2012 SHEET TITLE AGND PART # FIGURE 38. ISL26104 EV ISL26104AV ISL26104AV28EV1Z Schematics (Continued) DVDD AGND J23 AVDD AVDD J21 J19 DVDD 24 DVDD R4 R1 200 R2 200 C11 X7R 0.1uF AGND AVDD J4 SMA 200 C12 X7R 0.1uF R3 NO-POP DVDD 1 DVDD AGND XTALIN/CLOCK CAP XTALOUT VREF+ VREF- 20 VREF+ 19 VREF- AIN1+ AIN1- 11 AIN1+ 12 AIN1- AIN2+ AIN2- 18 AIN2+ 17 AIN2- AIN3+ AIN3- 13 AIN3+ 14 AIN3- AIN4+ AIN4- USB_5V AGND 6 D2 10 AVDD C10 NO-POP 0.1uF CAP DVDD 22 D1 9 AGND C6 X7R 0.1uF 3 Y1 4 4.9152 MHz J20 HDR4X2 2 1 3 4 5 6 7 8 ISL26104 CS SDO/RDY SDI SCLK AGND AGND 16 25 27 24 28 23 10 DGND 1 3 A1 4 A2 5 A3 6 A4 EN2/NC EN1/NC MOSI SCLK CS R36 7 2 GND1 8 GND1 SI8441BB AGND R9 10K J3 AGND VDD1 9 GND2 15 GND2 DVDD 26 8 7 DGND DGND 5 DGND 2 U1 ISL26104 21 AGND PWDN VDD2 14 B1 13 B2 12 B3 11 B4 LSPS 16 AIN4+ 15 AIN4- DGND U2 AGND SDI SCLK CS RDY LSPS C8 X7R 0.1uF C13 X7R 2700pF AGND PWDN HDR2X1 AGND FIGURE 39. DGND 1K MISO Application Note 1800 AGND C28 POLY 0.10uF DVDD AGND RED AGND RED AVDD AN1800.0 December 18, 2012 ISL26104AV28EV1Z Schematics (Continued) USB_5V SCLK MOSI MISO CS J1 HDR3X2 1 2 3 4 5 6 MISO SCLK RESET J22 HDR4X2 1 2 3 4 5 6 7 8 USB_5V MOSI C26 X7R 0.01uF DGND C24 X7R 0.1uF C25 X7R 0.1uF DGND 25 USB_5V USB_5V DGND R11 47K RESET LED1 LED2 LED3 R6 200 R7 200 R8 200 RESET 3 4 S1 U3 DGND USB_5V 24 RESET PC7(INT4/ICP1/CLKO) PC6(OC.1A/PCINT8) PC5(PCINT9/OC.1B) PC4(PCINT10) PC2(PCINT11) 4 VCC 32 AVCC 27 UCAP VBUS C23 X7R 1UF FB1 J18 USB USB_5V 1 PWR 2 D3 D+ 4 GND R5 22 R10 DGND 22 5 CASE 6 CASE 29 D+/SCK 30 D-/SDATA 31 UVCC 28 UGND 1 USB-B Y2 2 8.000MHz 3 C20 COG 22pF DGND DGND C22 COG 22pF DGND XTAL1 XTAL2 GND PD0(OC.0B/INT0) PD1(AIN0/INT1) PD2(RXD1/AIN1/INT2) PD3(TXD1/INT3) PD4(INT5) PD5(XCK/PCINT12) PD6(RTS/INT6) PD7(CTS/HWB/T0/INT7) PB0(SS/PCINT0) PB1(SCLK/PCINT1) PB2(PDI/MOSI/PCINT2) PB3(PDO/MISO/PCINT3) PB4(T1/PCINT4) PB5(PCINT5) PB6(PCINT6) PB7(PCINT7/OC.0A/OC.1C) AT90USB162-16AU DGND FIGURE 40. 22 23 25 26 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 PC7 PC6 PC5 PC4 PC2 PD3 4 3 2 1 5 6 7 8 SW4 SW3 SW2 SW1 S2 PB0 SW-DIP4 SCLK MOSI MISO CS PB5 PB6 PB7 DGND Application Note 1800 1 2 AN1800.0 December 18, 2012 Mouser Electronics Authorized Distributor Click to View Pricing, Inventory, Delivery & Lifecycle Information: Intersil: ISL26104AV28EV1Z