EVM Basic Functions
1-4
of the DAC is used, then the output op amp can only be configured for unity
gain. Shorting pins 1 and 2 of W13 allows the user to monitor the raw output
of the DAC7731. The J4 header is also used to monitor the output signal
through the external op amp for cascading or daisy-chaining up to three
DAC7731 EVMs. This can be done by properly configuring the W13 header
to route the DAC output of each respective EVM so that the output signal does
not stack up on top of the other. Of course it is also possible to stack more than
three EVMs as long as the W13 is left open and the output signal is monitored
through this same header in each respective EVM.
A block diagram of the EVM is shown in Figure 1 - 1.
Figure 1 - 1. EVM Block Diagram
DAC Module
(J4)
Output
Buffer
Module
VCC
VSS
VCC
+REFIN
Ext. Ref
Input
VCC
GND
GND
VDD
DAC Out
W13
W3
(J1)
(J3)
(J6)
External
Reference
Module
VDD
(J2)
(P2)
REFEN
RSTSEL
CS
SCLK
RST
LDAC
TP2
W4
TP1
VSS
REFin REFout
VSS
SDI
