BUF20800/20820EVM User Guide and Software Tutorial
This user's guide describes the characteristics, operation, and use of the BUF20800/20820EVM
evaluation board. It discusses how to set up and configure the software and hardware, and reviews
various aspects of the program operation. Throughout this document, the terms evaluation board,
evaluation module, and EVM are synonymous with the BUF20800/20820EVM. This document also
includes information regarding operating procedures and input/output connections, an electrical schematic,
printed circuit board (PCB) layout drawings, and a parts list for the EVM.
20Save to File Dialog Box Button and Window .......................................................................... 22
21File Format of Saved Data ............................................................................................... 22
22Load From File Button and Window .................................................................................... 23
23Run Batch Dialog Button and Window.................................................................................. 24
PowerPAD is a trademark of Texas Instruments.
Microsoft, Windows are registered trademarks of Microsoft Corporation.
I2C is a trademark of NXP Semiconductors.
WinZIP is a registered trademark of WinZip International LLC.
All other trademarks are the property of their respective owners.
SBOU100–April 2011BUF20800/20820EVM User Guide and Software Tutorial
5Bill of Materials ............................................................................................................ 29
1Overview
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List of Tables
The BUF20800 and BUF2082 are programmable gamma-voltage generators and V
BUF20800 offers two banks of 18 programmable gamma channels and two programmable V
calibrators. The
COM
COM
channels,
making it ideal for 10-bit source TFT-LCD reference drivers. The BUF20820 also features programmable
OTP memory that allows the user to store the gamma voltages on-chip, which eliminates the need for an
external EEPROM. The BUF20800/20820EVM is a platform for evaluating the performance of either the
BUF20800 or BUF20820 under various signal, reference, and supply conditions. This document gives a
general overview of the BUF20800/20820EVM, and provides a general description of the features and
functions to be considered while using this evaluation module. Unless otherwise noted, all references to
the device under test (DUT) apply to both the BUF20800 and the BUF20820.
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BUF20800/20820EVM User Guide and Software TutorialSBOU100–April 2011
Table 1 summarizes the contents of the BUF20800/20820EVM kit. Figure 1 shows all of the included
hardware. Contact the Texas Instruments Product Information Center nearest you if any component is
missing. It is highly recommended that you also check the BUF20800 product folder or the BUF20820
product folder on the TI web site at www.ti.com to verify that you have the latest versions of the related
software.
Table 1. BUF20800/20820EVM Kit Contents
ItemQuantity
BUF20800/20820 PCB Test Board1
USB_DIG_Platform PCB1
USB Cable1
+6V Power Supply1
User’s Guide CD-ROM1
Overview
Figure 1. Hardware Included with BUF20800/20820EVM Kit
SBOU100–April 2011BUF20800/20820EVM User Guide and Software Tutorial
The following documents provide information regarding Texas Instruments' integrated circuits used in the
assembly of the BUF20800/20820EVM. This user's guide is available from the TI web site under literature
number SBOU100. Any letter appended to the literature number corresponds to the document revision
that is current at the time of the writing of this document. Newer revisions may be available from the TI
web site, or call the Texas Instruments' Literature Response Center at (800) 477-8924 or the Product
Information Center at (972) 644-5580. When ordering, identify the document by both title and literature
number.
Related Documentation
DocumentLiterature Number
BUF20800/20820 Product DataSBOS329
Sheet
USB_DIG_Platform User GuideSBOU058
2BUF20800/20820EVM Hardware Setup
Figure 2 shows the system setup for the BUF20800/20820EVM. The PC runs software that communicates
with the USB_DIG_Platform. The USB_DIG_Platform generates the analog and digital signals used to
communicate with the BUF20800/20820 board. Connectors on the BUF20800/20820 allow the user to
connect to the system under test conditions where the power, current, and voltage are monitored.
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Figure 2. BUF20800/20820EVM Hardware Setup
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BUF20800/20820EVM User Guide and Software TutorialSBOU100–April 2011
2.1Theory of Operation for BUF20800/20820 Hardware
A block diagram of the BUF20800/20820 test board hardware setup is shown in Figure 3. The functionality
of the PCB is such that it provides connections to the I2C™ interface and general-purpose inputs/outputs
(GPIOs) on the USB_DIG_Platform board. It also provides connection points for external connections of
the shunt voltage, bus voltage, and ground.
BUF20800/20820EVM Hardware Setup
Figure 3. BUF20800/20820EVM Board Block Diagram
SBOU100–April 2011BUF20800/20820EVM User Guide and Software Tutorial
Figure 4 shows the block diagram for the USB_DIG_Platform. This platform is a general-purpose data
acquisition system that is used on several different Texas Instruments evaluation modules. The details of
its operation are included in a separate document, SBOU058 (available for download at www.ti.com). The
block diagram shown in Figure 4 gives a brief overview of the platform. The primary control device on the
USB_DIG_Platform is the TUSB3210.
BUF20800/20820EVM Hardware Overview
Figure 4. USB_DIG_Platform Block Diagram
3BUF20800/20820EVM Hardware Overview
The BUF20800/20820EVM hardware overview involves connecting the two PCBs of the EVM together,
applying power, connecting the USB cable, and setting the jumpers. This section presents the details of
this procedure.
3.1Electrostatic Discharge Warning
Many of the components on the BUF20800/20820EVM are susceptible to
damage by electrostatic discharge (ESD). Customers are advised to observe
proper ESD handling precautions when unpacking and handling the EVM,
including the use of a grounded wrist strap at an approved ESD workstation.
CAUTION
SBOU100–April 2011BUF20800/20820EVM User Guide and Software Tutorial
To set up the BUF20800/20820EVM hardware, connect the two PCBs of the EVM together, and apply a
power source to the BUF20800/20820EVM test board. The external connections may be the real-world
system that the BUF20800 or BUF20820 will be incorporated into. Figure 5 illustrates the typical hardware
connections.
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Figure 5. Typical Hardware Connections for BUF20800/20820EVM
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BUF20800/20820EVM User Guide and Software TutorialSBOU100–April 2011
To connect the two PCBs of the BUF20800/20820EVM together, gently push on both sides of the DSUB
connectors (as shown in Figure 6). Note that the USB_DIG_Platform board has two DSUB connectors;
either may be used. Make sure that the two connectors are completely pushed together; loose
connections may cause intermittent operation.
3.4Connecting Power
After the two parts of the BUF20800/20820EVM are conjoined, connect a +6V wall supply to the
USB_DIG_Platform board, as Figure 6 shows. Always connect power before connecting the USB cable. If
you connect the USB cable before connecting the power, the computer will attempt to communicate with
an unpowered device that will not be able to respond.
In addition, the BUF20800/20820EVM also requires an external power source. This source is not included
with the kit. Its voltage may differ depending on your testing needs, and it will be connected to the terminal
T1.
BUF20800/20820EVM Hardware Overview
Figure 6. Connecting External Power to the EVM
SBOU100–April 2011BUF20800/20820EVM User Guide and Software Tutorial
3.5Connecting the USB Cable to the BUF20800/20820EVM
Once power is connected, the USB cable must be connected to the USB_DIG_Platform, as shown in
Figure 7. Note that the BUF20800/20820EVM test board and the USB_DIG_Platform board must each be
powered on before connecting the USB cable. Typically, the computer will respond with a Found New
Hardware, USB Device pop-up dialog. The pop-up window typically changes to Found New Hardware,
USB Human Interface Device. This pop-up indicates that the device is ready to be used. The
USB_DIG_Platform uses the human interface device drivers that are part of the Microsoft®Windows
operating system.
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®
10
Figure 7. Connecting the USB Cable to the USB_DIG_Platform
In some cases, the Windows Add Hardware Wizard may pop up. If this prompt appears, allow the system
device manager to install the human interface drivers by clicking Yes when requested to install drivers.
Windows will confirm installation of the drivers with the message shown in Figure 8.
Figure 8. Confirmation of USB_DIG_Platform Driver Installation
BUF20800/20820EVM User Guide and Software TutorialSBOU100–April 2011