Texas Instruments ADS8688EVM-PDK User manual

User's Guide
SBAU230A–August 2014–Revised December 2014
ADS8688EVM-PDK Evaluation Module
ADS8688EVM-PDK
This user's guide describes the operation and use of the ADS8688 evaluation module (EVM). The
ADS8688 is an 8-channel integrated data acquisition system based on a 16-bit successive approximation
(SAR) analog-to-digital converter (ADC). Each input channel on the device can support true bipolar input
ranges of ±10.24 V, ±5.12 V, and ±2.56 V, as well as unipolar input ranges of 0 V to 10.24 V and 0 V to
5.12 V. The input range selection is done by software programming the device internal registers and is
independent for each channel. The device offers a 1-MΩ, constant resistive input impedance irrespective
of the selected input range This user's guide covers circuit description, schematic diagram, and bill of
materials for the ADS8688EVM circuit board.
Table 1 lists the related documents that are available through the Texas Instruments web site at
www.ti.com.
Table 1. Related Documentation
Device Literature Number
ADS8688 SBAS582
OPA376 SBOS406
OPA2209 SBOS426
OPA320 SBOS513
REG71055 SBAS221
TPA7A4901 SBVS121
TPS54060 SLVS919
TPS7A3001 SBVS125
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Contents
1 ADS8688EVM-PDK Overview ............................................................................................. 4
2 EVM Analog Interface....................................................................................................... 5
2.1 Connecting Negative Inputs to Ground .......................................................................... 6
2.2 Using Onboard, Second-Order, Butterworth, Low-Pass Filters............................................... 7
2.3 Selecting the Reference Mode for the ADS8688EVM......................................................... 7
3 Digital Interface .............................................................................................................. 8
3.1 Serial Interface (SPI) ............................................................................................... 8
3.2 I2C Bus for the Onboard EEPROM............................................................................... 8
3.3 SD Card.............................................................................................................. 8
4 Power Supplies .............................................................................................................. 9
5 ADS8688EVM-PDK Initial Setup......................................................................................... 11
5.1 Default Jumper Settings.......................................................................................... 11
5.2 Software Installation .............................................................................................. 12
6 ADS8688EVM-PDK Kit Operation ....................................................................................... 18
6.1 About the Simple Capture Card................................................................................. 18
6.2 Loading the ADS8688EVM GUI................................................................................. 18
6.3 Configuring the ADS8688EVM .................................................................................. 19
6.4 Capturing the Data................................................................................................ 22
6.5 Analyzing the Data................................................................................................ 26
6.6 Phase Compensation............................................................................................. 28
6.7 ADS8688EVM GUI Simulation Mode........................................................................... 30
7 Bill of Materials, Schematics, and Layout............................................................................... 31
7.1 Bill of Materials .................................................................................................... 31
7.2 Board Layouts ..................................................................................................... 34
List of Figures
1 ADS8688EVM Analog Input Connections for Channels AIN0, AIN1, AIN2, and AIN3 ............................. 5
2 ADS8688EVM Analog Input Connections for Channels AIN4, AIN5, AIN6, and AIN7 ............................ 5
3 Power-Supply Connections Diagram .................................................................................... 10
4 ADS8688EVM Default Jumper Settings................................................................................. 11
5 Bottom View of the Simple Capture card with the microSD Memory Card Installed.............................. 13
6 Bottom View of the ADS8688EVM Board with the microSD Memory Card Installed ............................. 13
7 Connecting the ADS8688EVM Board to the Simple Capture Card.................................................. 14
8 LED Indicators on the Simple Capture Card............................................................................ 14
9 Destination Directory Screen ............................................................................................. 15
10 License Agreement Screen ............................................................................................... 15
11 Start Installation Screen................................................................................................... 16
12 Progress Bar Screen....................................................................................................... 16
13 Windows 7 Driver Installation Warning.................................................................................. 16
14 Installation Wizard Screen ................................................................................................ 17
15 Simple Capture Card Device Driver Completion....................................................................... 17
16 Start Page of the ADS8688EVM GUI.................................................................................... 19
17 System Block Diagram View.............................................................................................. 20
18 Selecting the Input Range for the Channels............................................................................ 20
19 Register Map View......................................................................................................... 21
20 ADS8688EVM Jumper Settings.......................................................................................... 22
21 Manual Mode Data Capture .............................................................................................. 23
22 Data Capture in Auto Mode with Single Graph View.................................................................. 24
23 Data Capture in Auto Mode with Multi Graph View.................................................................... 25
24 Saving the Captured Data................................................................................................. 26
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25 Histogram Analysis......................................................................................................... 27
26 FFT Analysis................................................................................................................ 28
27 Phase Compensation Analysis........................................................................................... 29
28 Simulation Mode............................................................................................................ 30
29 ADS8688EVM PCB: Top Layer (L1)..................................................................................... 34
30 ADS8688EVM PCB: Ground Layer (L2) ................................................................................ 35
31 ADS8688EVM PCB: Analog Power Layer (L3) ........................................................................ 36
32 ADS8688EVM PCB: Digital Power Layer (L4) ......................................................................... 37
33 ADS8688EVM PCB: Ground Layer (L5) ................................................................................ 38
34 ADS8688EVM PCB: Bottom Layer (L6)................................................................................. 39
List of Tables
1 Related Documentation..................................................................................................... 1
2 J7: Analog Interface Connections ......................................................................................... 6
3 Connecting Negative Analog Inputs to Ground.......................................................................... 6
4 Using Onboard, Second-Order, Butterworth, Low-Pass Filters........................................................ 7
5 Bypassing the Onboard, Second-Order, Butterworth, Low-Pass Filters.............................................. 7
6 Selecting the Reference for the ADS8688EVM.......................................................................... 7
7 External Reference Connections .......................................................................................... 7
8 Connector J19 Pin Out...................................................................................................... 8
9 Jumper Settings for Generating HVDD and HVSS Using an Onboard Switching Regulator...................... 9
10 Jumper Settings for Generating HVDD and HVSS from External High-Voltage Supplies ......................... 9
11 Power-Supply Connections................................................................................................. 9
12 Default Jumper Configuration............................................................................................. 12
13 ADS8688EVM Bill of Materials .......................................................................................... 31
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1 ADS8688EVM-PDK Overview
The ADS8688EVM-PDK is a platform for evaluating the ADS8688 device. The ADS8688EVM-PDK
consists of an ADS8688EVM board and a Simple Capture card. The Simple Capture card is an FPGA-
based controller card that functions as an serial peripheral interface (SPI™) host and transfers data to the
ADS8688EVM graphical user interface (GUI) via a USB interface. The ADS8688EVM GUI collects,
analyzes, and records data from the ADS8688EVM board. The ADS8688EVM GUI is capable of collecting
data from the ADS8688EVM in auto and manual modes, configuring the ADC program registers, and
performing FFT analysis of data captured from the ADC.
ADS8688EVM Features
• Includes support circuitry as a design example to match ADC performance.
• 3.3-V slave SPI.
• Serial interface header for easy connection to the Simple Capture card.
• Designed for a 5-V analog supply.
• Integrated 4.096-V voltage reference.
• Bipolar (±10.24 V, ±5,12 V, ±2.56 V ) or unipolar (0 V to 10.24 V, 0 V to 5.12 V) input ranges for each
channel.
• Onboard, second-order, Butterworth, low-pass filters for four channels.
• Onboard regulator for generating a ±15-V bipolar supply for second-order, Butterworth, low-pass filters.
• Capable of accepting a ±100-mV signal on the negative analog inputs (AIN_xGND).
ADS8688EVM GUI Features:
• Captures data from the ADS8688EVM in auto and manual modes.
• Configures the ADS8688 device program registers.
• Enables and disables channels in auto mode.
• FFT analysis and calculates the SNR, THD, and SINAD ac performance parameters.
• Single and multiple graph views for captured data.
• Includes a dc histogram for dc inputs.
• Logs ADC data.
Windows is a registered trademark of Microsoft Corporation.
SPI is a trademark of Motorola.
Samtec is a trademark of Samtec Inc.
All other trademarks are the property of their respective owners.
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J7 ADS8688
AIN_xP
AIN_xGND
Ax+
Ax-
357 
357 10 nF
Optional
+
6.65k3.57k 2.2nF
1nF
J7
2nd Order Butterworth
Low Pass Filter ADS8688
AIN_xP
AIN_xGND
Ax+
Ax- J8,J9,
J10,J11
J25,J31,
J30,J15
357 
357 10 nF
Optional
Bypass Path
OPA2209
10 0
www.ti.com EVM Analog Interface
2 EVM Analog Interface
The ADS8688EVM is designed for easy interfacing to analog sources. The Samtec™ connector provides
a convenient 10-pin, dual-row, header at J7. Figure 1 and Figure 2 show the ADS8688EVM analog input
connections for channels AIN0 to AIN3 and channels AIN4 to AIN7, respectively. Table 2 lists the analog
interface connections for J7.
Figure 1. ADS8688EVM Analog Input Connections for Channels AIN0, AIN1, AIN2, and AIN3
Figure 2. ADS8688EVM Analog Input Connections for Channels AIN4, AIN5, AIN6, and AIN7
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Table 2 summarizes the J7 analog interface connector.
Table 2. J7: Analog Interface Connections
Pin
Number Signal Description
J7.2 A6+ Positive analog input for channel AIN6
J7.4 A7+ Positive analog input for channel AIN7
J7.6 A0+ Positive analog input for channel AIN0
J7.8 A1+ Positive analog input for channel AIN1
J7.10 AUX+ Positive analog input for AUX channel
J7.12 A2+ Positive analog input for channel AIN2
J7.14 A3+ Positive analog input for channel AIN3
J7.16 A4+ Positive analog input for channel AIN4
J7.18 A5+ Positive analog input for channel AIN5
J7.20 GND Analog ground connection
J7.1 A6– Negative analog input for channel AIN6
J7.3 A7– Negative analog input for channel AIN7
J7.5 A0– Negative analog input for channel AIN0
J7.7 A1– Negative analog input for channel AIN1
J7.9 AUX– Connected to analog ground
J7.11 A2– Negative analog input for channel AIN2
J7.13 A3– Negative analog input for channel AIN3
J7.15 A4– Negative analog input for channel AIN4
J7.17 A5– Negative analog input for channel AIN5
J7.19 GND Analog ground connection
2.1 Connecting Negative Inputs to Ground
The negative analog inputs for all channels (except for the AUX channel) are capable of accepting a ±100-
mV signal. The negative analog inputs can either be connected to the analog ground or a ±100-mV signal
can be applied on these inputs. Table 3 describes the appropriate jumper settings for connecting these
inputs to analog ground.
Table 3. Connecting Negative Analog Inputs to Ground
Position for Connecting to
Signal Jumper Analog Ground Position for Applying a ±100-mV Signal
A0– J22 Closed Open
A1– J16 Closed Open
A2– J26 Closed Open
A3– J27 Closed Open
A4– J28 Closed Open
A5– J29 Closed Open
A6– J24 Closed Open
A7– J23 Closed Open
AUX– NA Always connected to GND NA
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2.2 Using Onboard, Second-Order, Butterworth, Low-Pass Filters
The ADS8688EVM includes second-order, Butterworth, low-pass filters with a cutoff frequency of 22 kHz
for channels AIN0, AIN1, AIN2, and AIN3. There is also a provision to bypass these filters. See Figure 1
for an analog input circuit for channels AIN0, AIN1, AIN2, and AIN3. Table 4 lists the jumper settings for
using onboard, second-order, Butterworth, low-pass filters and Table 5 lists the jumper settings for
bypassing these filters.
Table 4. Using Onboard, Second-Order, Butterworth, Low-Pass Filters
Channel Jumper Position Jumper Position
AIN0 J25 Closed J8 Closed between pins 1 and 2
AIN1 J31 Closed J10 Closed between pins 1 and 2
AIN2 J30 Closed J11 Closed between pins 2 and 3
AIN3 J15 Closed J9 Closed between pins 2 and 3
Table 5. Bypassing the Onboard, Second-Order, Butterworth, Low-Pass Filters
Channel Jumper Position Jumper Position
AIN0 J25 Open J8 Closed between pins 2 and 3
AIN1 J31 Open J10 Closed between pins 2 and 3
AIN2 J30 Open J11 Closed between pins 1 and 2
AIN3 J15 Open J9 Closed between pins 1 and 2
2.3 Selecting the Reference Mode for the ADS8688EVM
The ADS8688EVM can either operate on an internal or external reference. Table 6 lists the jumper
settings for selecting the reference. Table 7 describes the connections for the external reference.
Table 6. Selecting the Reference for the ADS8688EVM
Position for Using Internal
Jumper Reference Position for Using External Reference
J2 Closed Open
Table 7. External Reference Connections
Pin
Number Signal Description
J5.1 REFIN Input for external reference
J5.2 GND Analog ground connection
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3 Digital Interface
Connector J19 (Samtec part number ERF8-025-01-L-D-RZ-L-TR socket strip connector) provides the
digital I/O connections between the ADS8688EVM board and the Simple Capture card. Consult Samtec at
www.samtec.com or call 1-800-SAMTEC-9 for a variety of mating connector options. Table 8 summarizes
the pin outs for connector J19.
Table 8. Connector J19 Pin Out
Pin Number Signal Description
J19.1 DAISY Daisy input for the ADC
J19.4 EVM_PRESENT EVM present, active low (connected to GND)
J19.5 REFSEL Reference selection input for the ADC
J19.6 RST/PD Reset or power-down input for the ADC
J19.8 A No connection
J19.11 EVM_ID_SDA I2C data for the onboard EEPROM
J19.12 EVM_ID_SCL I2C clock for the onboard EEPROM
J19.13 3V3_SDCC 3.3-V digital supply from the Simple Capture card
J19.14 5V_SDCC Unregulated 5-V supply from the Simple Capture card
J19.33, J19.34 SCLK Clock input for the ADC
J19.35 CS Chip-select input for the ADC
J19.38 SDI Data input for the ADC
J19.39 SDO Data output from the ADC
J19.45-49 EVMSDxxxxx Digital connections for the onboard SD card
J19.2, J19.10, J19.16, J19.50 GND Ground connections
3.1 Serial Interface (SPI)
The ADS8688 device uses SPI serial communication in mode 1 (CPOL = 0, CPHA = 1) with clock speeds
up to 17 MHz. The ADS8868xEVM offers 49.9-Ωresistors between the SPI signals and J19 to aid with
signal integrity. Typically, in high-speed SPI communication, fast signal edges can cause overshoot; these
49.9-Ωresistors slow down the signal edges in order to minimize signal overshoot.
3.2 I2C Bus for the Onboard EEPROM
The ADS8688EVM has an I2C bus that records the board name and assembly date to communicate with
the onboard EEPROM. The bus is not used in any form by the ADS8688 converter.
3.3 SD Card
The ADS8688EVM has an SD card that contains the software files for the Simple Capture card. The
contents of the SD card must not be deleted or altered.
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4 Power Supplies
The ADS8688EVM can be powered from the Simple Capture card if onboard buffers for active low-pass
filters are not being used and the onboard regulator (U9) for generating high-voltage supplies (HVDD and
HVSS) is disabled by closing jumper J17. The HVDD and HVSS supplies are only required for buffers U4
and U5.
CAUTION
Do not open jumper J17 if the ADS8688EVM must be powered only from the
Simple Capture card and an external 5-V supply is not provided on J32.
High-voltage supplies (HVDD and HVSS) for buffers U4 and U5 can be generated using the onboard
regulator (U9) if an external 5-V dc supply is provided on J32. The external 5-V dc supply must be at least
200 mV above the unregulated 5-V supply of the Simple Capture card. The external 5-V dc supply must
be capable of providing at least 500 mA of current. Table 9 provides jumper settings for generating HVDD
and HVSS using the onboard switching regulator U9.
Table 9. Jumper Settings for Generating HVDD and HVSS Using an Onboard Switching Regulator
Jumper Position for Using an Onboard Switching Regulator
J12 Closed between pins 1 and 2
J14 Closed between pins 1 and 2
J17 Open
HVDD and HVSS for buffers U4 and U5 can also be generated by providing external high-voltage supplies
on J18, as shown in Table 10.Table 11 and Figure 3 illustrate the power-supply connections for external
supplies.
Table 10. Jumper Settings for Generating HVDD and HVSS from External High-Voltage Supplies
Jumper Position for Generating HVDD and HVSS from External Voltage Supplies
J12 Closed between pins 2 and 3
J14 Closed between pins 2 and 3
J17 Closed
Table 11. Power-Supply Connections
Voltage Voltage
Supply Signal Range Pin Number Note
Required only for generating HVDD and HVSS using the
External 5 V EXT_5V 5 V to 5.5 V J32.2 onboard switching regulator
— GND GND J32.1 —
Required only for generating HVDD and HVSS from external
External HVDD EXT_HVDD 16 V to 25 V J18.3 high-voltage supplies
Required only for generating HVDD and HVSS from external
External HVSS EXT_HVSS –16 V to –25 V J18.1 high-voltage supplies
— GND GND J18.2 —
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Jumper for Disabling Onboard
regulator for HVDD and HVSS
Jumper for Selecting Source for
HVSS
Jumper for Selecting Source for
HVDD
External
HVSS
External
HVDD
GND External
5V
GND
Power Supplies www.ti.com
Figure 3. Power-Supply Connections Diagram
The AVDD analog supply for the ADS8688 is generated by converting an unregulated 5-V supply from the
Simple Capture card or by converting an external 5-V supply to a regulated 5-V supply by using the
REG71055 charge pump and the TPS7A4901 linear regulator. The DVDD digital supply for the ADC is
derived from a 3.3-V supply from the Simple Capture card.
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5 ADS8688EVM-PDK Initial Setup
This section presents the steps required to setup the ADS8688EVM-PDK kit before operation.
5.1 Default Jumper Settings
Figure 4 details the default jumper settings. Table 12 provides the configuration for these jumpers.
Figure 4. ADS8688EVM Default Jumper Settings
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Table 12. Default Jumper Configuration
Jumper Default Position
J2 Closed
J3 Open
J4 Closed
J5 Open
J6 Open
J8 Closed between pins 2 and 3
J9 Closed between pins 1 and 2
J10 Closed between pins 2 and 3
J11 Closed between pins 1 and 2
J12 Closed between pins 1 and 2
J13 Closed between pins 2 and 3
J14 Closed between pins 1 and 2
J15 Open
J16 Closed
J17 Closed
J21 Closed
J22 Closed
J23 Closed
J24 Closed
J25 Open
J26 Closed
J27 Closed
J28 Closed
J29 Closed
J30 Open
J31 Open
5.2 Software Installation
This section presents the steps required to the install the software.
NOTE: Ensure the microSD memory card included in the kit is installed in the microSD socket (P6)
on the back of the Simple Capture card before connecting the EVM to the computer.
Otherwise, as a result of improper boot up, Windows®cannot recognize the ADS8688EVM-
PDK as a connected device.
Complete the following steps to install the software:
1. Verify the microSD memory cards are installed on the Simple Capture card and the ADS8688EVM
board.
2. Verify jumpers are in the factory-default position and properly connect the hardware.
3. Install the ADS8688EVM-PDK software.
4. Complete the Simple Capture card device driver installation.
Each task is described in the following subsections.
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5.2.1 Verify the microSD Memory Card is Installed on the Simple Capture card
The ADS8688EVM-PDK includes microSD memory cards that contain the EVM software and Simple
Capture card firmware required for the EVM operation.
NOTE: Ensure the microSD memory cards that contain the software are installed in the microSD
socket on the back of the Simple Capture card and on the back of ADS8688EVM board.
Figure 5 and Figure 6 show the bottom view of the Simple Capture card and ADS8688EVM,
respectively, with the microSD card installed.
Figure 5. Bottom View of the Simple Capture card with the microSD Memory Card Installed
Figure 6. Bottom View of the ADS8688EVM Board with the microSD Memory Card Installed
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The microSD memory cards are formatted at the factory with the necessary firmware files for the Simple
Capture card to boot properly. In addition to the Simple Capture card firmware files (application and MLO
files), the microSD memory cards contain the ADS8688EVM-PDK software installation files.
5.2.2 Verify Jumpers are in the Factory-Default Position and Connect the Hardware
The ADS8688EVM-PDK includes both the ADS8688EVM and the Simple Capture card; however, the
devices are shipped unconnected. Follow these steps to verify that the ADS8688EVM-PDK kit is
configured and connected properly.
1. Verify the microSD card is installed on the back of the Simple Capture card ; see Figure 5.
2. Verify the microSD card is installed on the back of the ADS8688EVM; see Figure 6.
3. Verify the ADS8688EVM jumpers are configured as illustrated in Figure 4.
4. Connect the ADS8688EVM board to the Simple Capture card as Figure 7 illustrates.
Figure 7. Connecting the ADS8688EVM Board to the Simple Capture Card
5. Connect the Simple Capture card to the computer through the micro USB cable.
6. Verify that the LED D5 power-good indicator is illuminated. Wait approximately ten seconds and verify
that diode D2 blinks, indicating that USB communication with the host computer is functioning properly.
Figure 8 shows the location of the LED indicators in the Simple Capture card .
Figure 8. LED Indicators on the Simple Capture Card
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5.2.3 Install the ADS8688EVM-PDK Software
The ADS8688EVM software must be installed on the computer. This software supports the ADS688EVM-
PDK. The user must have administrator privileges to install the EVM software. The following steps list the
directions to install the software.
1. Open the Windows explorer and locate the microSD memory card labeled ADS8688EVM in the
browser as a removable storage device.
2. Navigate to the ...\ADS868xEVMGUI\Version x.x\Volume\ folder.
3. Run the installer by double-clicking the setup.exe file. This action installs the EVM GUI software and
the required and Simple Capture card device driver components.
4. After the installer begins, a welcome screen displays. Click Next to continue.
5. A prompt appears with the destination directory; select the default directory under: ...\Program
Files(x86)\Texas Instruments\ADS8684_8 EVM GUI\ as shown in Figure 9 and Figure 10.
Figure 9. Destination Directory Screen
Figure 10. License Agreement Screen
6. One or more software license agreements appear. Select the I Accept the License Agreement radial
button and click Next.
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7. The Start Installation screen appears, as shown in Figure 11. Click Next.
Figure 11. Start Installation Screen
8. A progress bar appears, as shown in Figure 12; this step takes a few minutes.
Figure 12. Progress Bar Screen
9. The progress bar is followed by an installation complete notice.
5.2.4 Complete the Simple Capture Card Device Driver Installation
During installation of the Simple Capture card device driver, a prompt may appear with the Windows
security message shown in Figure 13. Select Install this driver software anyway to install the driver
required for proper operation of the software. The drivers contained within the installers are safe for
installation to your system.
Figure 13. Windows 7 Driver Installation Warning
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NOTE: Driver installation prompts do not appear if the Simple Capture card device driver is already
installed on your system.
The following steps describe how to install the Simple Capture card device driver.
1. Immediately after the ADS8688 EVM software installation is complete, prompts appear to install the
Simple Capture card device driver, as shown in Figure 14 and Figure 15.
2. A computer restart may be required to finish the software installation. If prompted, restart the computer
to complete the installation.
Figure 14. Installation Wizard Screen
Figure 15. Simple Capture Card Device Driver Completion
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6 ADS8688EVM-PDK Kit Operation
This section describes how to use the ADS8688EVM-PDK and ADS8688EVM GUI to configure the EVM
and acquire data.
6.1 About the Simple Capture Card
The Simple Capture card provides the USB interface between the computer and the ADS8688EVM. The
controller board is designed around the AM335x processor, a USB 2.0, high-speed capability, 32-bit, ARM
core. The Simple Capture card incorporates an onboard FPGA subsystem and 256MB of onboard DDR
SRAM memory.
The Simple Capture card is not sold as a development board, and is not available separately. TI cannot
offer support for the Simple Capture card except as part of this EVM kit.
6.2 Loading the ADS8688EVM GUI
The ADS8688EVM GUI provides control over the settings of the ADS8688. Adjust the ADS8688EVM
settings when the EVM is not acquiring data. During acquisition, all controls are disabled and settings
cannot be changed.
When you change a setting on the ADS8688EVM GUI, the setting immediately updates on the board.
Settings on the ADS8688EVM correspond to settings described in the ADS8688 product data sheet
(available for download at www.ti.com); see the product data sheet for details.
To load the ADS8688EVM GUI, follow these steps.
Step 1. Make sure the PDK kit is configured and powered up as explained in Section 5.2.2.
Step 2. Start the ADS8688EVM GUI. Go to Start→All Programs→Texas Instruments→ADS8684_8
EVM GUI and click ADS8684_8 EVM GUI to run the software.
Step 3. Verify that the software detects the ADS8688EVM. The GUI identifies the EVM that is
connected to the controller and loads the settings. After the settings are loaded, the
ADS8688EVM GUI is displayed on the top of GUI window; see Figure 16.
Step 4. Verify that the Simulate Connection box is un-checked on the top right corner and connected
is displayed on bottom edge of GUI window.
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Figure 16. Start Page of the ADS8688EVM GUI
6.3 Configuring the ADS8688EVM
6.3.1 System Block Diagram View
The ADS8688 channels can be configured by the system block diagram view in the GUI. The system
block diagram can be activated by clicking on the Program Register button on the left side of the GUI
window. A channel can be powered down by checking the AINx_PD box. if a channel is powered down,
that channel turns grey in system block view. The voltage range for each channel can be selected from a
drop-down menu corresponding to each channel in the system block diagram view; see Figure 17.
Figure 18 displays the window for selecting the input voltage ranges.
19
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Figure 17. System Block Diagram View
Figure 18. Selecting the Input Range for the Channels
20 ADS8688EVM-PDK Evaluation Module SBAU230A–August 2014–Revised December 2014
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