*
DAC Module
O
u
tp
u
t
B
u
ff
e
r
M
o
d
u
le
VCC
VSS
+3 .3 VD
VCC
+ 5 VD
GND
+5 VA
DAC Out
(J1 )
(J5 )
(J6 )
(P 6)
External
Reference
Module
(J2)
(P 2)
SCLK
FSYNC
TP 4
VSS
REF
IN
+ 5VD
DIN
(J4)
(P 4 )
TP 3
DV
DD
W 15
W 5
VSS
AGND
V
OUT
TP 2
W 1
DAC Module features the DAC8580/81.
+3 .3VD
W4
AV
DD
OSR 1
RSTB
MUTEB
OSR 2
BPB
1 CH
+ 5 VA
AV
SS
-5VA
TP 1
J3
U 1
-5VA
*
www.ti.com
PCB Design and Performance
1.3
EVM Basic Functions
This EVM is designed primarily as a functional evaluation platform to test certain functional characteristics
of the DAC8580/81 digital-to-analog converter. Functional evaluation of the installed DAC device can be
accomplished with the use of any microprocessor, TI DSP, or some sort of a signal/waveform generator.
The headers J2 (top side) and P2 (bottom side) are pass-through connectors provided to allow the control
signals and data required to interface a host processor or waveform generator to the DAC8580/81EVM
using a custom-built cable.
The DAC output can be monitored through the J4 header connector. In addition, the DAC output can be
connected to the output operational amplifier, U2, by using a jumper across any of the pins 1-2, 3-4, 5-6,
or 7-8 of the J4 header terminal. The input signal going into the output operational amplifier, U2, must be
configured correctly on the J3 header to achieve the desired output waveform. The output operational
amplifier, U2, is configurable through J3, W5, and W15 for any desired waveform characteristic.
shows a block diagram of the DAC8580/81EVM.
Figure 1. DAC8580/81EVM Block Diagram
2
PCB Design and Performance
This section discusses the layout design of the PCB, describing the physical and mechanical
characteristics of the EVM. It shows the resulting performance of the EVM, which can be compared to the
device specification listed in the data sheet. The list of components used on the module is also included in
this section.
2.1
PCB Layout
The DAC8580/81EVM is designed to demonstrate the performance quality of the installed DAC device
under test (DUT), as specified in the data sheet. To take full advantage of the EVM capabilities, use care
during the schematic design phase to properly select the right components and to build the circuit
correctly. The circuit should include adequate bypassing, identifying and managing the analog and digital
signals, and understanding the component electrical and mechanical attributes.
The main design concern during the layout process is the optimal placement of components and the
proper routing of signals. Place the bypass capacitors as close as possible to the pins, and the analog and
digital signals should be properly separated from each other. In the layout process, carefully consider the
power and ground planes because of their importance. A solid plane is ideally preferred but because of its
greater cost, sometimes a split plane can be used satisfactorily. When considering a split plane design,
3
SLAU173A – December 2005 – Revised November 2009
DAC8580/81 Evaluation Module
Copyright © 2005–2009, Texas Instruments Incorporated
