Texas Instruments ADS7043EVM-PDK User manual

User's Guide
SBAU241–November 2014
ADS7043EVM-PDK
This user's guide describes the characteristics, operation and use of the ADS7043-EVM performance
demonstration kit (PDK). This kit is an evaluation platform for the ADS7043 low power, 12-bit pseudo-
differential successive approximation register (SAR) analog-to-digital converters (ADCs) that support
single-ended analog inputs.
This EVM eases the evaluation of the ADS7043 device with hardware and software for computer
connectivity through universal serial bus (USB). This user's guide includes complete circuit descriptions,
schematic diagrams, and a bill of materials.
The following related documents are available through the Texas Instruments web site at
http://www.ti.com.
Table 1. Related Documentation
Device Literature Number
OPA316 SBOS703
TPS79101 SLVS325
REG71055 SBAS221
TPS62080 SLVSAE8
TPS3836K33 SGLS322
Contents
1 Overview...................................................................................................................... 3
1.1 ADS7043EVM Features ........................................................................................... 3
1.2 ADS7043EVM-PDK Features..................................................................................... 3
2 EVM Analog Interface....................................................................................................... 3
3 Power Supplies .............................................................................................................. 4
4 Digital Interface .............................................................................................................. 5
5 ADS7043EVM-PDK Initial Setup .......................................................................................... 5
5.1 Default Jumper Settings ........................................................................................... 5
5.2 Software Installation................................................................................................ 6
Microsoft, Windows are registered trademarks of Microsoft Corporation.
All other trademarks are the property of their respective owners.
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6 ADS7043EVM-PDK Kit Operation ....................................................................................... 12
6.1 About the SCC Controller Board ................................................................................ 12
6.2 Loading the ADS7043EVM Software........................................................................... 12
6.3 Capturing Data with the ADS7043-PDK........................................................................ 13
6.4 FFT Analysis....................................................................................................... 15
6.5 Histogram Analysis................................................................................................ 16
6.6 Offset Calibration.................................................................................................. 17
6.7 Estimated Current Consumption ................................................................................ 18
6.8 Troubleshooting ................................................................................................... 18
7 Bill of Materials, PCB Layout, and Schematics......................................................................... 19
7.1 Bill of Materials .................................................................................................... 19
7.2 PCB Layout ........................................................................................................ 20
7.3 Schematics......................................................................................................... 22
List of Figures
1 ADS7043EVM Analog Input Connections................................................................................ 3
2 ADS7043EVM Default Jumper Settings .................................................................................. 5
3 Bottom View of Simple Capture Card with microSD Memory Card Installed........................................ 6
4 Bottom View of ADS7043EVM Board with microSD Memory Card Installed ....................................... 7
5 Connecting ADS7043EVM Board to Simple Capture Card ............................................................ 8
6 LED Indicators on the Simple Capture Card............................................................................. 8
7 Welcome Screen and Destination Directory Screens................................................................... 9
8 License Agreement and Start Installation Screens...................................................................... 9
9 Progress Bar and Installation Complete Screens...................................................................... 10
10 Windows 7 Driver Installation Warning.................................................................................. 10
11 Simple Capture Card Driver Installation................................................................................. 11
12 Simple Capture Card Driver Completion................................................................................ 11
13 GUI Display Prompt........................................................................................................ 12
14 Open the Data Capture Page on the GUI............................................................................... 13
15 Data Capture Page......................................................................................................... 14
16 FFT Performance Analysis Page......................................................................................... 15
17 Histogram Analysis Page.................................................................................................. 16
18 Offset Calibration Page.................................................................................................... 17
19 Estimated Current Consumption Page .................................................................................. 18
20 ADS7043EVM PCB: Top Layer (L1)..................................................................................... 20
21 ADS7043EVM PCB: GND Layer (L2) ................................................................................... 20
22 ADS7043EVM PCB: Power Layer (L3).................................................................................. 21
23 ADS7043EVM PCB: Bottom Layer (L4)................................................................................. 21
List of Tables
1 Related Documentation..................................................................................................... 1
2 Analog Input Connections .................................................................................................. 3
3 AVDD Voltage Settings ..................................................................................................... 4
4 Voltage Supply Options..................................................................................................... 4
5 Default Jumper Configurations............................................................................................. 5
6 ADS7043EVM Bill of Materials ........................................................................................... 19
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AVDD
AVDD
68 
VIN
OPA316
AINP
AINM GND
AVDD
Device
Input Driver
Device: 12-Bit, 1-MSPS
Pseudo-Differential Input
+
1 nF
68 
AVDD
OPA316
+
AVDD/2
0.5 nF
0.5 nF
20 k
20 k
www.ti.com Overview
1 Overview
The ADS7043EVM-PDK is a platform for evaluation of the ADS7043 ADC. The evaluation kit combines
the ADS7043EVM board with a Simple Capture Card controller board. This controller card consists of a TI
Sitara embedded microcontroller (AM3352) and a field-programmable gate array (FPGA). It provides an
interface from the EVM to the computer through a universal serial bus (USB) port. The included software
communicates with the Simple Capture Card, and the controller card provides the power and digital
signals used to communicate with the ADS7043EVM board. These demonstration kits include the
ADS7043EVM board, the Simple Capture Card, a microSD memory card, and an A-to-micro-B USB cable.
1.1 ADS7043EVM Features
• Contains support circuitry as a design example to match ADC performance
• 3.3-V slave serial peripheral interface (SPI)
• Onboard 5-V analog supply
• Onboard OPA316 (10-MHz, low-power, low-noise, Rail-to-Rail Out (RRIO)) ADC input drivers
1.2 ADS7043EVM-PDK Features
• USB port for computer interface
• Easy-to-use evaluation software for Microsoft®Windows®XP, Windows 7, and Windows 8 operating
systems
• Built-in analysis tools including scope, FFT, and histogram displays
• Data collection to text files supported
2 EVM Analog Interface
The ADS7043 is an extremely low-power, extremely small size ADC that supports single-channel ended
analog inputs. The ADS7043EVM uses an OPA316 amplifier to drive the inputs of the ADC. The
ADS7043EVM is designed for easy interfacing to multiple analog sources. SMA connector J3 (please refer
to the schematics in Section 7.3) allows the EVM to have input signals connected through a coaxial cable.
In addition, header connector P2 provides a convenient way to connect input signals. All analog inputs are
buffered by the OPA316 amplifier in order to properly drive the ADS7043 ADC inputs.
Figure 1. ADS7043EVM Analog Input Connections
Table 2 lists the analog interface connectors available. The ADS7043EVM accepts a signal of –AVDD / 2
to AVDD / 2 on J3 with common mode voltage of AVDD / 2. The AINM pin of the ADS7043 is set to AVDD
/ 2 by OPA316 buffer (U1). Connecting an input signal greater than AVDD would cause the ADC output
codes to saturate.
Table 2. Analog Input Connections
Reference Designator Signal Signal Description
J3 AINP Positive input of the pseudo-differential signal provided at the SMA
J4 AINP Alternate location to provide the pseudo-differential input signal
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Power Supplies www.ti.com
3 Power Supplies
The ADS7043 supports a wide range of operation on its analog supplies. The AVDD can operate from 1.8
V to 3.6 V. The DVDD operates from 1.65 V to 3.6 V, independent of the AVDD supply.
The analog portion of the ADS7043EVM-PDK operates from a 5-V supply. The ADS7043EVM-PDK is
configured to use the onboard regulated analog 5-V supply that in turn generates an AVDD analog supply
using the low-noise TPS79101 LDO. This supply is nominally set to 3.3 V at the factory, but this voltage
maybe changed to any value within the valid range, by modifying the value of R15 as per Table 3. In case
any intermediate value needs to be set, the detailed formula to arrive at these values are available in the
TPS79101 (SGLS160) datasheet.
Table 3. AVDD Voltage Settings
AVDD Voltage R15 R19 C9
1.8 V 14.2 kΩ30.1 kΩ33 pF
2.0 V 19.1 kΩ30.1 kΩ27 pF
2.5 V 31.6 kΩ30.1 kΩ22 pF
3.0 V 43.7 kΩ30.1 kΩ15 pF
3.3 V (default) 51.1 kΩ30.1 kΩ15 pF
3.6 V 59.0 kΩ30.1 kΩ15 pF
By default, the OPA316 amplifier supplies, VDD_OPA and VSS_OPA, are tied to AVDD (supplied from the
same LDO) and GND, respectively. DVDD_ADC is set at 3.3 V from the controller. These three supplies
may be externally supplied by making the modifications described in Table 4.
Table 4. Voltage Supply Options
Supply Supply Option Source Component Setting
VDD_OPA Onboard AVDD LDO (U5) R47 Assembled
External J7/pin1 R47 Disassembled
VSS_OPA Onboard GND R48 Assembled
External J7/pin3 R48 Disassembled
DVDD_ADC Onboard 3V3_SDCC supply from connector R49 Assembled
External J9/pin1 R49 Disassembled
CAUTION
The external AVDD supply applied to external connector P3 must not exceed
3.6 V as this may damage the device. The external AVDD supply must be in
the range of 1.8 V to 3.6 V for proper operation of the ADS7043EVM.
The digital portion of the ADS7043 ADC operates from a 3.3-V supply from the Simple Capture Card. The
buffer U12 is included to ensure that the SDO can be driven to the controller with minimal distortion.
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4 Digital Interface
The ADS7043 digital output is available in SPI-compatible format, which makes interfacing with
microprocessors, digital signal processors (DSPs) and FPGAs easy. The ADS7043EVM offers 50-Ω
resistors between the SPI signals and edge connector J1 to aid with signal integrity. Typically, in high-
speed SPI communication, fast signal edges can cause overshoot; these resistors slow down the signal
edges in order to minimize signal overshoot.
The ADS7043EVM has clearly marked test points for all the SPI signals to allow observation of the
interface signals using an oscilloscope.
5 ADS7043EVM-PDK Initial Setup
This section presents the steps required to set up the ADS7043EVM-PDK kit before operation.
5.1 Default Jumper Settings
A silkscreen plot detailing the default jumper settings is shown in Figure 2.
Table 5 explains the configuration for these jumpers.
Figure 2. ADS7043EVM Default Jumper Settings
Table 5. Default Jumper Configurations
Reference Default Description
Designator Position
J2 Open Alternate location to provide the negative input of the differential signal
J4 Open Unassembled, by default
J5 Closed Point to insert an ammeter to measure VDD_ADC current, if required
J11 Closed Point to insert an ammeter to measure VDD_OPA current, if required
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5.2 Software Installation
This section presents the steps required to the install the software. Section 6 explains how to operate the
software to acquire data.
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 as well as the microSD socket (J2) before
connecting the EVM to the PC. Also ensure that the cards are not swapped or overwritten. If
the contents of these cards are not available during boot up, Windows will not recognize the
ADS7043EVM-PDK as a connected device.
Complete the following steps to install the software:
Step 1. Ensure that the microSD memory cards on both the Simple Capture Card and ADS7043 are
installed.
Step 2. Verify jumpers are in the factory-default positions and connect the hardware.
Step 3. Locate, copy and install the ADS7043EVM software to the PC.
Step 4. Complete the device driver installation.
Each of these steps is described in the following subsections.
5.2.1 Install the microSD Memory Cards on the Simple Capture Card Controller Board
As mentioned in the previous section, the ADS7043EVM-PDK includes two microSD memory cards. One
is installed on the microSD socket (P6) at the back of the Simple Capture Card as shown in Figure 3. The
second microSD memory card is installed on the mircoSD socket (J2) at the back of the ADS7043EVM as
shown in Figure 4.
Figure 3. Bottom View of Simple Capture Card with microSD Memory Card Installed
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Figure 4. Bottom View of ADS7043EVM Board with microSD Memory Card Installed
The microSD memory card is formatted at the factory with the necessary firmware files for the Simple
Capture Card to boot properly. In addition to this the microSD card on the EVM contain Simple Capture
Card firmware files (app and MLO files) and the ADS7043EVM-PDK software installation files inside the
ADS7043 EVM V#.#.# folder. <V#.#.#> refers to the installation software version number, and increments
with software installer releases.
5.2.2 Verify Jumpers are in the Factory-Default Position and Connect the Hardware
The ADS7043EVM-PDK includes both the ADS7043EVM and the Simple Capture Card; however, the
boards are shipped unconnected.
Follow these steps to verify that ADS7043EVM-PDK kit is configured and connected properly:
Step 1. Verify the ADS7043EVM jumpers are configured as shown in Figure 2.
Step 2. Verify the microSD card is installed on the back of the Simple Capture Card, as shown in
Figure 3.
Step 3. Verify the microSD card is installed on the back of the EVM board, as shown in Figure 4.
Step 4. Connect the ADS7043EVM board to the Simple Capture Card as Figure 5 illustrates.
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Figure 5. Connecting ADS7043EVM Board to Simple Capture Card
Step 5. Connect the Simple Capture Card to the PC through the micro USB cable.
Step 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 PC is
functioning properly. Figure 6 shows the location of the LED indicators in the Simple Capture
Card.
Figure 6. LED Indicators on the Simple Capture Card
5.2.3 Install the ADS7043EVM-PDK Software
The ADS7043 EVM V#.#.# software must be installed on the PC. This software supports the ADS7043-
PDK. Administrator privileges are required to install the EVM software. The following steps list the
directions to install the software:
Step 1. Open Windows Explorer and find the microSD memory card in the browser as a storage
device.
Step 2. Navigate to the ...\ADS7043 EVM Vx.x.x\Volume\ folder.
Step 3. Run the installer by double-clicking the file setup.exe. This action installs the EVM GUI
software and the required and device driver components.
Step 4. After the installer begins, a welcome screen displays. Click Next to continue.
Step 5. A prompt appears with the destination directory; select the default directory
under: ...\Program Files(x86)\Texas Instruments\ADS7043evm\.
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Figure 7. Welcome Screen and Destination Directory Screens
Step 6. One or more software license agreements appear. Select I Accept the License Agreement
and click Next.
Step 7. The Start Installation screen appears. Click Next.
Figure 8. License Agreement and Start Installation Screens
Step 8. A progress bar appears; this step takes a few minutes.
Step 9. The progress bar is followed by an Installation Complete notice.
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Figure 9. Progress Bar and Installation Complete Screens
5.2.4 Complete the Simple Capture Card Driver Installation
During installation of the Simple Capture Card driver, a prompt may appear with the Windows security
message shown in Figure 10. 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 10. Windows 7 Driver Installation Warning
NOTE: Driver installation prompts do not appear if the Simple Capture Card driver has been
installed on your system previously.
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