Datasheet

UG-470 Evaluation Board User Guide
Rev. 0 | Page 4 of 20
DIGITAL INTERFACE
The E VA L-AD5143DBZ can be configured as an I
2
C or SPI
digital interface, depending on the position in the A1 jumper.
If the part is configured in I
2
C mode, the ADDR0 and ADDR1
jumpers select the I
2
C address.
TEST CIRCUITS
The E VA L-AD5143DBZ and E VA L-MB-LV-SDZ incorporate
several test circuits to evaluate the performance of the AD5143.
DAC
The redundant disk array controller (RDAC) can be operated as
a digital-to-analog converter (DAC), as shown in Figure 2.
Table 4 shows the options available for the voltage references.
The output voltage is defined in Equation 1.
256
)(
RDAC1
VVV
B
A
OUT
×−=
(1)
where:
RDAC1 is the code loaded in the RDAC1 register.
V
A
is the voltage applied to the A terminal (A9 link).
V
B
is the voltage applied to the B terminal (A10 link).
However, by using the R34 and R35 external resistors, the user
can reduce the voltage of the voltage references. In this case, use
the A1 and B1 test points to measure the voltage applied to the
A and B terminals and to recalculate V
A
and V
B
in Equation 1.
Table 4. DAC Voltage References
Terminal Link Options Description
A1 A9 AC+ Connects Terminal A1 to
V
DD
/2
VDD Connects Terminal A1 to
V
DD
W1 BUF-W1 Connects Terminal W1 to
an output buffer
B1 A10 BIAS Connects Terminal B1 to
V
DD
/2
VSS Connects Terminal B1 to
V
SS
AGND Connects Terminal B1 to
analog ground
VOUT1
R34
R35
A1
W1
RDAC1
A1
B1
W1
VDD
V
DD
AC+
V
DD
2
V
DD
2
AGND
BIAS
B1
VSS
V
SS
BUF-W1
11007-002
Figure 2. DAC