Datasheet

3.4 Output Operational Amplifier
1 2 3
JMP15
1 2 3
JMP15
Bottom
EVM
Top
EVM
1 2 3
JMP16
1 2 3
JMP16
TopEVM, J4A
BottomEVM, J4A
ShuntJ4A pins 1 and 2
ShuntJ4A pins 3 and 4
MonitorDACoutputof
topEVMonJ4A pin 5
MonitorDACoutputof
bottomEVMonJ4A pin 7
www.ti.com EVM Operation
Table 3. DAC Output Channel Mapping
Reference Jumper Position Function
JMP11 1-2 DAC output (V
OUT
A) is routed to J4-2.
2-3 DAC output (V
OUT
A) is routed to J4-10.
JMP12 1-2 DAC output (V
OUT
B) is routed to J4-4.
2-3 DAC output (V
OUT
B) is routed to J4-12.
JMP13 1-2 DAC output (V
OUT
C) is routed to J4-6.
2-3 DAC output (V
OUT
C) is routed to J4-14.
JMP14 1-2 DAC output (V
OUT
D) is routed to J4-8.
2-3 DAC output (V
OUT
D) is routed to J4-16.
In order to allow exclusive control of each EVM that is stacked together, the DAC8164/65 must have
separate SYNC signal. This is accomplished in hardware by routing the SYNC signal of the first EVM
through CS (J2A/J2B pin 1) by shorting pins 1-2 of jumper JMP18. The second EVM must use the FSX
signal (J2A/J2B pin 7) to drive the SYNC signal by shorting pins 2-3 of the jumper JMP18. The outputs
can be mapped as described in Table 3 for each of the EVMs stacked.
The EVM includes an optional signal-conditioning circuit for the DAC output through an external
operational amplifier, U2. During stacking of the EVMs, only two DAC output channels can be monitored
at any given time for evaluation because of the way the odd-numbered pins of J4 header (J4A-1 to J4A-7)
are configured. See the schematic included in this manual and Section 3.3 .
Figure 10. DAC8164/65EVM Output Operational Amplifier Jumper Configuration for Stacking
The output operational amplifier is set to unity gain configuration by default but can be modified by simple
jumper settings. Nevertheless, the raw output of the DAC can be probed through the specified pins of J4
output terminal, which also provides mechanical stability when stacking or plugging into any interface
board. In addition, it provides easy access for monitoring up to two (DAC8164/65) DAC channels when
stacking two EVMs together (see Section 3.3 ).
The following sections describe the different configurations of the output amplifier, U2.
SLAU256 – August 2008 DAC8164/65 Evaluation Module 11
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