Texas Instruments PGA308 User manual

PGA308EVM
User's Guide
Literature Number: SBOU060
July 2008

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Contents
Preface ............................................................................................................................... 5
1 Overview ................................................................................................................... 71.1 PGA308EVM Hardware ..................................................................................................... 8
2 System Setup ............................................................................................................ 92.1 Theory of Operation for the PGA308 Test Board Hardware .......................................................... 102.2 Signal Definition of J1 (25-Pin Male DSUB) on the PGA308 Test Board ........................................... 112.3 Signal Definition of J2 (25-Pin Female DSUB) on the PGA308 Test Board ........................................ 122.4 Theory of Operation For the USB DAQ Platform ...................................................................... 13
3 Hardware Connections and Jumper Settings ............................................................... 153.1 Typical Hardware Connections ........................................................................................... 153.2 Connecting the Hardware ................................................................................................. 163.3 Connecting Power .......................................................................................................... 173.4 Connecting the USB Cable to the PGA308EVM ....................................................................... 183.5 Jumper Settings ............................................................................................................ 19
4 PGA308 Software Overview ....................................................................................... 234.1 Operating Systems for the PGA308 Software .......................................................................... 234.2 PGA308EVM Software Install ............................................................................................ 234.3 Starting the PGA308EVM Software ...................................................................................... 244.4 Using the PGA308 Software .............................................................................................. 274.4.1 Block Diagram ..................................................................................................... 274.4.2 Registers in OTP .................................................................................................. 274.4.3 Registers in RAM .................................................................................................. 274.4.4 Calibration ......................................................................................................... 274.4.5 Simulation ......................................................................................................... 274.4.6 Graph .............................................................................................................. 274.5 EVM Pull-Down Menus .................................................................................................... 284.5.1 PGA308 Controls ................................................................................................. 284.5.2 USB Controls ...................................................................................................... 284.5.3 Help ................................................................................................................. 29
A Bill of Materials ........................................................................................................ 31A.1 Resistors and Capacitors.................................................................................................. 31A.2 Active Devices and Miscellaneous ....................................................................................... 32
Important Notices ............................................................................................................... 33
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List of Figures
1-1 Hardware Included with the PGA308EVM ................................................................................ 82-1 Hardware Setup for the PGA308EVM .................................................................................... 92-2 Block Diagram of the PGA308 Test Board ............................................................................. 102-3 Theory of Operation For the USB DAQ Platform ...................................................................... 133-1 Typical Hardware Connections ........................................................................................... 153-2 Connecting the Two EVM PCBs ......................................................................................... 163-3 Connecting Power to the EVM ........................................................................................... 173-4 Connecting the USB Cable ............................................................................................... 183-5 Default Jumper Settings ................................................................................................... 194-1 PGA308EVM Software—Functioning Properly ......................................................................... 244-2 PGA308EVM Software—No Communication with the USB DAQ Platform ......................................... 254-3 PGA308EVM Software—No Communication from USB DAQ Platform to PGA308 .............................. 264-4 PGA309 Controls ........................................................................................................... 284-5 USB Controls ............................................................................................................... 284-6 Current Revision of Software ............................................................................................. 29
List of Tables
2-1 Signal Definition of J1 ..................................................................................................... 112-2 Signal Definition of J2 ..................................................................................................... 123-1 PGA308 Test Board Jumper Function ................................................................................... 203-2 USB DAQ Platform Jumper Settings (5V Power Supply) ............................................................. 21
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Preface
SBOU060 – July 2008
About This Manual
This user's guide describes the characteristics, operation, and use of the PGA308 evaluation module(EVM). It discusses the processes and procedures required to properly use this EVM board. Thisdocument also includes the physical printed circuit board (PCB) layout, schematic diagram, and circuitdescriptions.
Related Documentation from Texas InstrumentsThe following documents provide information regarding Texas Instruments integrated circuits used in theassembly of the PGA308EVM. These documents are available from the TI web site under the respectiveliterature number (for example, SBxxnnn). Any letter appended to the literature number corresponds to thedocument revision that is current at the time of the writing of this User’s Guide. Newer revisions may beavailable from the TI web site at www.ti.com , or call the Texas Instruments Literature Response Center at(800) 477-8924 or the Product Information Center at [phone]. When ordering, identify thedocument by both title and literature number.Documents Literature Number
PGA308 SBOS440XTR116 SBOS124TUSB3210 SLLS466USB DAQ Platform SBOU056
Information About Cautions and WarningsThis document contains caution statements.
CAUTION
This is an example of a caution statement. A caution statement describes asituation that could potentially damage your software or equipment.
The information in a caution or a warning is provided for your protection. Please read each cautioncarefully.
FCC Warning
This equipment is intended for use in a laboratory test environment only. It generates, uses, and canradiate radio frequency energy and has not been tested for compliance with the limits of computingdevices pursuant to subpart J of part 15 of FCC rules, which are designed to provide reasonableprotection against radio frequency interference. Operation of this equipment in other environments maycause interference with radio communications, in which case the user at his own expense is required totake whatever measures may be required to correct this interference.
Windows Vista is a trademark of Microsoft Corporation.Microsoft, Windows are registered trademarks of Microsoft Corporation.All other trademarks are the property of their respective owners.
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Chapter 1SBOU060 – July 2008
Overview
This document provides the information needed to set up and operate the PGA308EVM evaluationmodule, a test platform for the PGA308 Programmable Bridge Sensor . For a more detailed description ofthis device, please refer to the PGA308 product data sheet (SBOS440) available from the TexasInstruments web site at www.ti.com . Support documents are listed in the section of this guide entitledRelated Documentation from Texas Instruments .
The PGA308EVM is an evaluation module that is used to fully evaluate the PGA308 device. The PGA308is a mixed-signal programmable gain amplifier that has high resolution gain and offset adjustmentcapability.
The PGA308EVM consists of two PCBs. One board generates the digital signals (USB DAQ Platform)required to communicate with the PGA308 (PGA308_Test_Board), and the second board contains thePGA308, as well as support and configuration circuitry.
Note: Note: Much of the information contained in this document is also contained in the QuickStartVideo (SBOU059) , which is included with the EVM kit. It is highly recommended that youwatch this video before using this EVM.
Throughout this document, the abbreviation EVM and the term evaluation module are synonymous withthe PGA308EVM.
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1.1 PGA308EVM Hardware
PGA308EVM Hardware www.ti.com
Figure 1-1 shows the hardware included with the PGA308EVM kit. Contact the factory if any component ismissing. It is highly recommended that you check the TI web sit at www.ti.com to verify that you have thelatest software version. It is also recommended that you watch the QuickStart Video (included on thecompact disk) before using the PGA308EVM.
The complete kit includes the following items:•PGA308 test PCB•USB DAQ platform PCB•USB cable•Universal 6V wall-wart power supply•QuickStart Video
Figure 1-1. Hardware Included with the PGA308EVM
8Overview SBOU060 – July 2008Submit Documentation Feedback

USB DAQ
Platform
PGA308
Test Board
Sensor
Connections
EVM
Power
Chapter 2SBOU060 – July 2008
System Setup
Figure 2-1 shows the system setup for the PGA308EVM. The PC runs software that communicates withthe USB DAQ platform. The USB DAQ platform generates the digital signals used to communicate withthe PGA308 test board. Connectors on the PGA308 test board allow for connection to the system that willbe monitored by the user.
Minimim PC operating requirements:•Microsoft
®
Windows
®
XP or higher (including Windows Vista™)•USB port•Works on US or European regional settings
Figure 2-1. Hardware Setup for the PGA308EVM
SBOU060 – July 2008 System Setup 9Submit Documentation Feedback

2.1 Theory of Operation for the PGA308 Test Board Hardware
PGA308
One-Wire
Interface
V (5.0V Power)
DUT
Connection to
Sensor
25-Pin Male DSUB Signals
from USB DAQ Platform
25-Pin Female DSUB Signals
from USB DAQ Platform
Sensor
Emulator
4-20mA
V/I
Reference
Configure
Clamp
Connection
to VOUT
Connection
to VREF
Connection
to VCLAMP
Theory of Operation for the PGA308 Test Board Hardware www.ti.com
Figure 2-2 shows the block diagram of the PGA308 test board. The PGA308 test board functionality isrelatively simple. It provides connections to the one-wire interface, digital-to-analog converter (DAC),analog-to-digital converter (ADC), and general-purpose inputs/outputs (GPIOs) on the USB DAQ platform.It also provides connection points for external connection of the bridge sensor, reference, and outputs.
Figure 2-2. Block Diagram of the PGA308 Test Board
Refer to SBOR004 for the PGA308 test board schematic, available for download at www.ti.com .
System Setup10 SBOU060 – July 2008Submit Documentation Feedback

2.2 Signal Definition of J1 (25-Pin Male DSUB) on the PGA308 Test Board
www.ti.com Signal Definition of J1 (25-Pin Male DSUB) on the PGA308 Test Board
Table 2-1 shows the different signals connected to J1 on the PGA308 test board. Table 2-1 also identifiessignals connected to pins on J1 that are not used on the PGA308 test board.
Table 2-1. Signal Definition of J1
Signal Name from USBPin Number DAQ Platform Description
1 DAC_A To input amplifier (sensor emulator); 16-bit string DAC A output.2 DAC_B To input amplifier (sensor emulator); 16-bit string DAC B output.3 DAC_C To input amplifier (sensor emulator); 16-bit string DAC C.4 DAC_D Not used5 ADS1_V
IN+
To PGA308 output; 16-bit delta-sigma ( Δ Σ ) ADC #1 positive input.6 ADS1_V
IN–
Grounded for single-ended measurements; 16-bit Δ Σ ADC #1 negative input.7 ADS2_V
IN+
PGA308 V
IN2
input; 16-bit Δ Σ ADC #2 positive input.8 ADS2_V
IN–
PGA308 V
IN1
input; 16-bit Δ Σ ADC #2 negative input.9 I
2
C_SCK Not used10 I
2
C_SDA2 Not used
PGA308 1W pin; one-wire signal11 ONE_WIRE
(derived from the UART on the TUSB3210 device).12 I
2
C_SDA_ISO Not used13 I
2
C_SCK_ISO Not used
To XTR116 pin 7 on EVM. Current-loop positive-loop connection;14 XTR+LOOP
this signal is connected to the positive-loop supply.To XTR116 pin 4 on EVM. Current-loop negative-loop connection;15 XTR–LOOP
this signal connects the DUT current output to the current measurement circuit.16 INA– Not used17 V
DUT
To PGA308 V
S
power-supply pin; switched 3V or 5V supply.18 V
CC
Not used19 +15V Not used20 –15V Not used21 GND Ground22 SPI_SCK Not used23 SPI_CS1 Not used24 SPI_DOUT1 Not used25 SPI_DIN1 Not used
SBOU060 – July 2008 System Setup 11Submit Documentation Feedback

2.3 Signal Definition of J2 (25-Pin Female DSUB) on the PGA308 Test Board
Signal Definition of J2 (25-Pin Female DSUB) on the PGA308 Test Board www.ti.com
Table 2-2 shows the different signals connected to J2 on the PGA308 test board. Table 2-2 also identifiessignals connected to pins on J2 that are not used on the PGA308 test board.
Table 2-2. Signal Definition of J2
Signal Name from USBPin Number DAQ Platform Description
1 P3.3 Not used2 CTRL1 Not used3 CTRL2 Not used4 CTRL3 Not used5 CTRL4 Not used6 CTRL5 Not used7 CTRL6 Not used8 CTRL7 Not used9 CTRL8 Not used
To D
OUT
on the PGA308. This pin is a measure bit that can read logic signals;10 MEAS1
it is part of an 8-bit group.11 MEAS2 Not used12 MEAS3 Not used13 MEAS4 Not used14 MEAS5 Not used15 MEAS6 Not used16 MEAS7 Not used17 MEAS8 Not used18 SPI_SCK Not used19 SPI_CS2 Not used20 SPI_DOUT2 Not used21 SPI_DIN2 Not used22 V
DUT
Not used23 V
CC
Not used24 GND Not used25 GND Not used
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2.4 Theory of Operation For the USB DAQ Platform
TUSB3210 8052 C
with USB Interface
and UART
m
USB Bus
from Computer
3.3V
Regulator
Adjustable
Regulator
V
(2.7V to 5.5V)
CC
V Cm
S
3.3V
V_USB
5V
8k x 8 Byte
EEPROM
Buffers and
Latches
Power
Switching
V
(2.7V to 5.5V)
DUT
Switched Power
I C SPI
Control Bits
Measure Bits
2
External Power
(6V DC)
Reset Button and
Power-On-Reset
USB DAQ Platform
Reference
Circuits
4x 16-Bit String DAC
2x 16-Bit DS ADC
4-20mA
Loop Receiver
Loop Switching
Circuit
External Power
V = 40V DC
Loop Measurement
Circuitry = 15V
LOOP
±
4-20mA Reciever
2x 16-Bit ADCDS
2x 16-Bit ADCDS
Calibration
EEPROM
To Computer and
Power Supplies To Test Board
www.ti.com Theory of Operation For the USB DAQ Platform
Figure 2-3 shows the block diagram for the USB DAQ platform. This platform is a general-purpose dataacquisition system that is used on several different Texas Instruments evaluation modules. The blockdiagram shown in Figure 2-3 illustrates the general platform outline. The core component of the USB DAQplatform is the TUSB3210.
Figure 2-3. Theory of Operation For the USB DAQ Platform
SBOU060 – July 2008 System Setup 13Submit Documentation Feedback

System Setup14 SBOU060 – July 2008Submit Documentation Feedback

3.1 Typical Hardware Connections
Chapter 3SBOU060 – July 2008
Hardware Connections and Jumper Settings
Many of the components on the PGA308EVM are susceptible to damage by electrostatic discharge (ESD).Customers are advised to observe proper ESD handling precautions when unpacking and handling theEVM, including the use of a grounded wrist strap at an approved ESD workstation.
CAUTION
Failure to observe ESD handling procedures may result in damage to EVMcomponents.
A typical PGA308EVM hardware setup connects the two EVM PCBs, then supplies power and connectsan external shunt and load. The external connections may be the real-world system to which the PGA308will be connected. Figure 3-1 shows the typical hardware connections.
Figure 3-1. Typical Hardware Connections
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3.2 Connecting the Hardware
Connecting the Hardware www.ti.com
The best way to connect the two PGA308EVM PCBs together is to gently push on both sides of the DSUBconnectors, as shown in Figure 3-2 . Make sure that the two connectors are completely socketed together;loose connections may cause intermittent EVM operation.
Figure 3-2. Connecting the Two EVM PCBs
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3.3 Connecting Power
www.ti.com Connecting Power
Connect the two PGA308EVM PCBs before connecting a power source, as shown in Figure 3-3 .Alwaysconnect power before connecting the USB cable. If the USB cable is connected before the power issupplied, the computer will attempt to communicate with an unpowered device, and the device will not beable to respond.
Figure 3-3. Connecting Power to the EVM
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3.4 Connecting the USB Cable to the PGA308EVM
Connecting the USB Cable to the PGA308EVM www.ti.com
Figure 3-4 shows the typical response to connecting the USB DAQ platform to a PC USB port for the firsttime. Note that the EVM must be powered up before connecting the USB cable. Typically, the computerwill respond with a Found New Hardware, USB Device pop-up. The pop-up typically changes to FoundNew Hardware, USB Human Interface Device. This pop-up indicates that the device is ready to be used.The USB DAQ platform uses the Human Interface Device Drivers that are part of the Microsoft Windowsoperating system. In some cases, the Windows Add Hardware Wizard will pop-up. If this prompt occurs,allow the system device manager to install the Human Interface Drivers by clicking Yes when requested toinstall drivers.
Figure 3-4. Connecting the USB Cable
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3.5 Jumper Settings
www.ti.com Jumper Settings
Figure 3-5 shows the default jumper configuration for the PGA308EVM. In general, the jumper settings ofthe USB DAQ platform do not need to be changed. However, you may want to change some of thejumpers on the PGA308 test board to match your specific device configuration (for example, to change thereference configuration).
Figure 3-5. Default Jumper Settings
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Jumper Settings www.ti.com
Table 3-1 explains the function of the jumpers on the PGA308 test board.
Table 3-1. PGA308 Test Board Jumper Function
Jumper Default Purpose
JMP2 V
REF
= Fixed/XTR Select ratiometric or absolute sensor configurationJMP3 Fixed V
REF
Fixed references on the EVM or XTR referenceJMP4 4.096V 4.096V or 2.5V allows selection between the two fixed references on the EVM.Internal references or external references. (Note: internal references are references on theJMP5 Internal V
REF
EVM. The PGA308 does not have a reference inside the device.)ADS1 or NC allows you to connect or disconnect the ADC on the USB DAQ platform to theJMP6 ADS1
PGA308 output.Auto or EXT allows connection of an external sensor or the onboard sensor emulator signalJMP17 Auto source. The sensor emulator is useful tool during initial development; i.e. learn how thedevice works before connecting the real sensor.Auto or EXT allows connection of an external sensor or the onboard sensor emulator signalJMP18 Auto source. The sensor emulator is a useful tool during initial development; i.e. learn how thedevice works before connecting the real sensor.ADS– or NC allows you to connect or disconnect the ADC on the USB DAQ platform to theJMP9 ADS– PGA308 input. Note that the ADC has a switched capacitor input, so it can affect the inputsignal. It is recommended that ADCs be disconnected when using a real-world sensor.ADS+ or NC allows you to connect or disconnect the ADC on the USB DAQ platform to theJMP10 ADS+ PGA308 input. Note that the ADC has a switched capacitor input, so it can affect the inputsignal. It is recommended that ADCs be disconnected when using a real-world sensor.V
OUT
to XTR or NC. Allows connection of the current-loop transmitter (XTR). In the NCJMP13 NC position, the EVM output if voltage only. In the V
OUT
to XTR position, the output is 4mA to20mA.
V
OUT
to 1W or NC. In the V
OUT
to 1W position, the communication line (1W) to the analogJMP1 NC output (V
OUT
). This configuration is called a three-wire module because it only requires V
S
,V
OUT
, and GND outputs.One to V
OUT
or One to 1W. In the One to V
OUT
position, the communication line (1W) tothe analog output (V
OUT
). This configuration is called a three-wire module because it onlyJMP7 One to 1W
requires V
S
, V
OUT
, and GND outputs. In the One to 1W position, the communication line isseparate from V
OUT
.V
EXC
= V
REF
or V
EXC
= V
S
allows choice of either the power supply (such as ratiometric) orJMP15 V
EXC
= V
REF
the reference to excite the sensor (that is, absolute mode).JMP11 Dout D
OUT
or V
CLAMP
allows choice between a digital output or a clamp input.JMP16 V
CLAMP
Divider V
CLAMP
divider or Ext V
CLAMP
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