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DAC8775EVM
User Manual
20 pgs2.89 Mb0

Texas Instruments DAC8775EVM User Manual

User's Guide
SBAU248–November 2016
DAC8775EVM User’s Guide
Contents
1 Overview...................................................................................................................... 2
2 EVM Hardware Overview................................................................................................... 3
3 EVM Software Setup....................................................................................................... 10
4 EVM Software Overview .................................................................................................. 12
5 EVM Documentation....................................................................................................... 15
List of Figures
1 DAC8775EVM Hardware Setup ........................................................................................... 3
2 DAC8775EVM Block Diagram ............................................................................................. 3
3 PVDD/AVDD, AVSS, and DVDD Supply Connections ................................................................. 6
4 Digital Communication Test Points........................................................................................ 7
5 Onboard Reference Supply Connections................................................................................. 8
6 Output Terminal Block Connections and Load Jumpers ............................................................... 9
7 SM-USB-DIG Connection................................................................................................... 9
8 DAC8775EVM Installer.................................................................................................... 10
9 DAC8775EVM Install Path................................................................................................ 11
10 DAC8775EVM Software License Agreements ......................................................................... 11
11 EVM GUI – Front Panel ................................................................................................... 12
12 Device Schematic .......................................................................................................... 15
13 DC-DC Schematic.......................................................................................................... 16
14 Outputs Schematic......................................................................................................... 16
15 DAC8775EVM PCB Components Layout............................................................................... 17
1 Contents of DAC8775EVM Kit ............................................................................................. 2
2 Related Documentation ..................................................................................................... 2
3 EVM Jumper Summary ..................................................................................................... 4
4 SM-USB-DIG Connector .................................................................................................. 10
5 EVM Board Bill of Materials............................................................................................... 18
SBAU248–November 2016
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List of Tables
Copyright © 2016, Texas Instruments Incorporated
DAC8775EVM User’s Guide
1
Overview
Trademarks
Windows XP, Windows 7 are registered trademarks of Microsoft.
1 Overview
The DAC8775 is a four-channel (quad) 16-bit precision digital-to-analog converter (DAC). Each output can be configured to produce a current in output ranges of 0 to 20 mA, 0 to 24 mA, 3.5 to 23.5 mA, or ±24 mA. Each channel can also be configured for voltage output in ranges of 0 to 5 V, 0 to 6 V, 0 to 10 V, 0 to 12 V, ±5 V, ±6 V, ±10 V, or ±12 V. The DAC8775 includes integrated buck-boost converters for each channel to generate all necessary power supplies from a single external supply. The buck-boost converter features various operating modes that can be used to enhance power dissipation and thermal performance. The DAC8775 features additional peripherals including: HART input pins for coupling of FSK HART Voltage signals, slew-rate control for the analog outputs, and reliability features such as CRC, watchdog timer, and conditional alarms.
1.1 EVM Kit Contents
Table 1 details the contents of the EVM kit. Contact the nearest Texas Instruments Product Information
Center or visit the Texas Instruments E2E Community (http://E2E.ti.com) if any component is missing.
ITEM NO ITEM QTY DESCRIPTION OR USE
1 DAC8775EVM PCB 1 EVM hardware 2 USB Extension Cable 1 Connects PC USB port to SM-USB-DIG USB connector 3 SM-USB-DIG Platform 1 Platform used for digital communication from PC to EVM
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Table 1. Contents of DAC8775EVM Kit
1.2 Related Documentation From Texas Instruments
The following documents provide information regarding Texas Instruments integrated circuits used in the assembly of the DAC8775EVM. This user’s guide is available from the TI website under the literature number SBAU248. 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 website at http://www.ti.com/, or by calling the Texas Instruments Literature Response Center at 1-800-477-8924 or the Product Information Center at 1-972-644-5580. When ordering identify the document by both title and literature number.
Table 2. Related Documentation
ITEM NO LITERATURE NUMBER
DAC8775 product data sheet SLVSBY7 REF5050 product data sheet SBOS410 SM-USB-DIG platform user’s guide SBOU098
2
DAC8775EVM User’s Guide
Copyright © 2016, Texas Instruments Incorporated
SBAU248–November 2016
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Copyright © 2016, Texas Instruments Incorporated
DAC8775
PVDD/AVDD
Power Supply
VOUT
A
IOUT
A
VOUT
D
IOUT
D
...
...
HARTIN
X
IEC61000-4 Protection Circuit
Placeholder
External Supplies
SM-USB-DIG
VPOSX/VNEG
X
Internal Buck-Boost
External V
REF
REF5050
Internal V
REF
V
REF
SPI
Computer
SM-USB-DIG
Platform
DAC8775EVM
Power Supply
USB 10-Pin Connector
Single-supply for use with buck-boost converter Multi-supply for use without buck-boost converter
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2 EVM Hardware Overview
This section discusses the overall system setup for the EVM. A personal computer (PC) runs the software that communicates with the SM-USB-DIG platform, which provides the power and digital signals used to communicate with the EVM board. Connectors on the EVM board allow the user to connect the required external power supplies for the configuration under test. The SM-USB-DIG must be connected to the DAC8775EVM with the Texas Instruments logo facing up.
Figure 1. DAC8775EVM Hardware Setup
2.1 EVM Board Block Diagram
A block diagram of the EVM board setup is shown in Figure 2. This board provides test points for the SPI, power, reference, ground, analog outputs, !LDAC, CLR, ALARM, and RESET signals. The EVM allows the user to select the internal buck-boost converter or external power supplies as sources for each channel’s positive and negative supplies rails. The EVM also allows the user to select the internal reference, onboard REF5050 reference, or external reference to provide the reference voltage to the DAC8775.
EVM Hardware Overview
SBAU248–November 2016
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Figure 2. DAC8775EVM Block Diagram
Copyright © 2016, Texas Instruments Incorporated
DAC8775EVM User’s Guide
3
EVM Hardware Overview
2.2 Electrostatic Discharge Warning
Many of the components on the EVM are susceptible to damage by electrostatic discharge (ESD). Users 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.
2.3 Jumper Summary
Table 3 summarizes all of the EVM jumper functionality.
JUMPER LABEL DEFAULT POSITION FUNCTION
JP1 1-2
JP2 1-2
JP3 1-2
JP4 1-2
JP5 1-2
JP6 1-2
JP7 1-2
JP8 1-2
JP9 Not installed
JP10 1-2
JP11 Not installed
JP12 2-3
JP13 Not installed
JP14 Not installed
JP15 Installed
JP16 Installed
JP17 Installed
JP18 Not installed
JP19 Installed
JP20 Not installed
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Table 3. EVM Jumper Summary
1-2 Selects DC/DC Channel A to supply VPOSA 2-3 Selects PVDD/AVDD to supply VPOSA 1-2 Selects DC/DC Channel A to supply VNEGA 2-3 Selects AVSS to supply VNEGA 1-2 Selects DC/DC Channel B to supply VPOSB 2-3 Selects PVDD/AVDD to supply VPOSB 1-2 Selects DC/DC Channel B to supply VNEGB 2-3 Selects AVSS to supply VNEGB 1-2 Selects DC/DC Channel C to supply VPOSC 2-3 Selects PVDD/AVDD to supply VPOSC 1-2 Selects DC/DC Channel C to supply VNEGC 2-3 Selects AVSS to supply VNEGC 1-2 Selects DC/DC Channel D to supply VPOSD 2-3 Selects PVDD/AVDD to supply VPOSD 1-2 Selects DC/DC Channel D to supply VNEGD 2-3 Selects AVSS to supply VNEGD
Installed Connects the SM-USB-DIG supply to DVDD
Not installed Disconnects the SM-USB-DIG supply from DVDD
1-2 Selects the DAC8775 internal reference 2-3 Selects the REF5050 external reference
Installed Disables internal DVDD LDO
Not installed Enables internal DVDD LDO
1-2 Issues a clear command to the DAC8775 2-3 No operation
Installed Selects the external DVDD
Not installed Disconnects the external DVDD
Installed Issues a hardware reset to the DAC8775
Not installed No operation
Installed Select asynchronous update mode
Not installed Select synchronous update mode
Installed VSENSEPA is shorted to VOUTA on-board
Not installed VSENSEPA is shorted to VOUTA off-board
Installed VSENSEPB is shorted to VOUTB onboard
Not installed VSENSEPB is shorted to VOUTB off-board
Installed Loads VOUTA/IOUTA with a short to GND
Not installed Unloads VOUTA/IOUTA of the short to GND
Installed Loads VOUTA/IOUTA with a 250-Ω resistor
Not installed Unloads VOUTA/IOUTA of the 250-Ω resistor
Installed Loads VOUTA/IOUTA with a 625-Ω resistor
Not installed Unloads VOUTA/IOUTA of the 625-Ω resistor
4
DAC8775EVM User’s Guide
SBAU248–November 2016
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Copyright © 2016, Texas Instruments Incorporated
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Table 3. EVM Jumper Summary (continued)
JUMPER LABEL DEFAULT POSITION FUNCTION
JP21 Not installed
JP22 Not installed
JP23 Not installed
JP24 Not installed
JP25 Not installed
JP26 Installed
JP27 Installed
JP28 Installed
JP29 Installed
JP30 Installed
JP31 Installed
JP32 Not installed
JP33 Not installed
JP34 Not installed
JP35 Not installed
JP36 Not installed
JP37 Not installed
JP38 Not installed
JP39 Not installed
JP40 Installed
JP41 Installed
JP42 Installed
JP43 Installed
Installed Loads VOUTA/IOUTA with a 1-kΩ resistor
Not installed Unloads VOUTA/IOUTA the 1-kΩ resistor
Installed Loads VOUTB/IOUTB with a short to GND
Not installed Unloads VOUTB/IOUTB of the short to GND
Installed Loads VOUTB/IOUTB with a 250-Ω resistor
Not installed Unloads VOUTB/IOUTB of the 250-Ω resistor
Installed Loads VOUTB/IOUTB with a 625-Ω resistor
Not installed Unloads VOUTB/IOUTB of the 625-Ω resistor
Installed Loads VOUTB/IOUTB with a 1-kΩ resistor
Not installed Unloads VOUTB/IOUTB the 1-kΩ resistor
Installed VSENSENA is shorted to GND onboard
Not installed VSENSENA is shorted to GND off-board
Installed VSENSENB is shorted to GND onboard
Not installed VSENSENB is shorted to GND off-board
Installed When HARTIN_A is not in use, AC couple to GND
Not installed When HARTIN_A is in use, disconnect from GND
Installed When HARTIN_B is not in use, AC couple to GND
Not installed When HARTIN_B is in use, disconnect from GND
Installed VSENSEPC is shorted to VOUTA onboard
Not installed VSENSEPC is shorted to VOUTA off-board
Installed VSENSEPD is shorted to VOUTB onboard
Not installed VSENSEPD is shorted to VOUTB off-board
Installed Loads VOUTC/IOUTC with a short to GND
Not installed Unloads VOUTC/IOUTC of the short to GND
Installed Loads VOUTC/IOUTC with a 250-Ω resistor
Not installed Unloads VOUTC/IOUTC of the 250-Ω resistor
Installed Loads VOUTC/IOUTC with a 625-Ω resistor
Not installed Unloads VOUTC/IOUTC of the 625-Ω resistor
Installed Loads VOUTC/IOUTC with a 1-kΩ resistor
Not installed Unloads VOUTC/IOUTC the 1-kΩ resistor
Installed Loads VOUTD/IOUTD with a short to GND
Not installed Unloads VOUTD/IOUTD of the short to GND
Installed Loads VOUTD/IOUTD with a 250-Ω resistor
Not installed Unloads VOUTD/IOUTD of the 250-Ω resistor
Installed Loads VOUTD/IOUTD with a 625-Ω resistor
Not installed Unloads VOUTD/IOUTD of the 625-Ω resistor
Installed Loads VOUTD/IOUTD with a 1-kΩ resistor
Not installed Unloads VOUTD/IOUTD the 1-kΩ resistor
Installed VSENSENC is shorted to GND onboard
Not installed VSENSENC is shorted to GND off-board
Installed VSENSEND is shorted to GND onboard
Not installed VSENSEND is shorted to GND off-board
Installed When HARTIN_C is not in use, AC couple to GND
Not installed When HARTIN_C is in use, disconnect from GND
Installed When HARTIN_D is not in use, AC couple to GND
Not installed When HARTIN_D is in use, disconnect from GND
EVM Hardware Overview
SBAU248–November 2016
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Copyright © 2016, Texas Instruments Incorporated
DAC8775EVM User’s Guide
5
PVDD/AVDD
GND
AVSS
GND
GND
DVDD
EVM Hardware Overview
2.4 Powering the EVM
This section describes the various power configurations that can be used by the EVM.
2.4.1 PVDD_X/AVDD Supply
The PVDD_X, the buck-boost converter supplies, and AVDD, the analog supply, of the DAC8775 are connected to the same power net labeled PVDD/AVDD on the DAC8775EVM. Terminal block J2, shown in Figure 3, allows for external voltage sources to be connected to the PVDD/AVDD supply. The PVDD/AVDD supply must be provided regardless of whether the buck-boost converter is in use or not.
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Figure 3. PVDD/AVDD, AVSS, and DVDD Supply Connections
2.4.2 VPOS_X and VNEG_X Supplies
VPOS_X, the positive supply for the output signal chain, and VNEG_X, the negative supply for the output signal chain, may be powered by the DAC8775 internal buck-boost converters or by off-board supply voltages.
Permanent device damage may occur if externally supplying VPOS_X or VNEG_X while the internal buck-boost supply is enabled.
When using the DAC8775 internal buck-boost converters to supply VPOS_X and VNEG_X, install JP1 through JP8 (or the two jumpers that correspond to the channel of interest) in the 1-2 position, or "inside" position, as indicated by Table 3.
When using external equipment to supply VPOS_X and VNEG_X, install JP1 through JP8 (or the two jumpers that correspond to the channel of interest) in the 2-3 position, or "outside" position, as indicated by Table 3. In this configuration, the VPOS_X supplies are connected to the PVDD/AVDD net and the VNEG_X supplies are connected to the AVSS net. If bipolar supplies are used, connect an appropriate negative supply voltage to AVSS through terminal block J3, as shown in Figure 3. If unipolar supplies are used, connect AVSS to ground through terminal block J3.
WARNING
6
DAC8775EVM User’s Guide
Copyright © 2016, Texas Instruments Incorporated
SBAU248–November 2016
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