Texas Instruments DAC8580, Руководство пользователя

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EVM Operation
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3 EVM Operation
This section covers in detail the EVM operation to provide guidance to the user in evaluating the onboard
DAC and how to interface the EVM to a host processor.
See the specific DAC data sheet, as listed in the Related Documentation from Texas Instruments section
(
Section 3.5 ) of this user guide for more information about the DAC serial interface and other related
topics.
The EVM board is factory-tested and configured to operate in the bipolar output mode.
3.1 Factory Default Setting
The EVM board is set to its default configuration from the factory as described in Table 1 to operate in
bipolar ±5-V output operation as measured from TP5. The default jumper settings below are shown in
Figure 10 and Figure 11 for each respective EVM.
Table 1. DAC8580/81EVM Factory Default Jumper Setting
DAC8580/81EVM Jumper Default Configuration
Reference Jumper Position Function
W1 2-3 DV
DD
is powered at +3.3 VD.
W4 1-2 DAC reference is sourced externally from U3.
W5 1-2 Negative supply rail of U2 operational amplifier is sourced by V
SS
.
W7 CLOSE OSR1 is tied low, configured for 2x oversampling rate. This is hardwired to DGND for the
DAC8580/81EVM.
W8 CLOSE OSR2 is tied low, configured for 2x oversampling rate. This is hardwired to DGND for the
DAC8580/81EVM.
W9 CLOSE RSTB is tied low so the DAC is configured for conventional operation. Digital filter is
disconnected. This is hardwired to DGND for the DAC8580/81EVM.
W10 CLOSE BPB is tied low so the DAC is configured for conventional operation. Digital filter is
disconnected. This is hardwired to DGND for the DAC8580/81EVM.
W14 1-2 The CS signal is routed to FSYNC to synchronize the data word.
W15 CLOSE Output operational amplifier is configured for a gain of 2.
W16 OPEN MUTEB/CLR is high so that the DAC8580/DAC8581 output is not set to midscale (~0V).
W17 CLOSE (For For the DAC8580EVM, this jumper must be connected to digital ground reference for proper
DAC8580EVM) operation.
OPEN (For For the DAC8581EVM, this jumper must be connected to DV
DD
for proper operation;
DAC8581EVM) therefore, the jumper is not installed.
J3 2-3 DAC output is tied to the noninverting input of the output operational amplifier.
J4 1-2 DAC V
OUT
is routed to the J3 jumper.
J6 5-6 AGND and DGND are tied together.
8 DAC8580/81 Evaluation Module SLAU173A – December 2005 – Revised November 2009
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