UG-266
EVAL-CN-304-SDZ Evaluation Board User Guide
Rev. B | Page 6 of 12
Waveform Options
The output waveform options that can be selected are sinusoidal
waveform or ramp waveform. The SIGN BIT OUT pin output
can be selected using three options: selecting
MSB
or
MSB/2
of
the phase accumulator or selecting the internal comparator. If
this pin is not used, click
DISABLE
(see Figure 9).
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009
Figure 9. Waveform Profile and SIGN BIT OUT
Power-Down Options
The
AD9834
has various power-down options selected through
the control register. The master clock (MCLK) or the DAC can
be disabled, or both sections can be powered down for a lower
power sleep mode (see Figure 10).
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Figure 10. Power-Down Options
Hardware Options
If the hardware programming method is selected (see Figure 6),
the FSELECT (
FSEL0
), PSELECT (
PSEL0
),
RESET
, and
SLEEP
pin functions can be toggled. The GPIO outputs on the
EVAL-
SDP-CB1Z
board control these pin functions. For example,
frequency data can be loaded to the FREQ 0 register and the
FREQ 1 register and the output can be toggled by the FSELECT
pin, that is, 2FSK functionality.
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0
1
1
Figure 11. GPIO Hardware Pin Control
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012
Figure 12. FSEL0 Hardware Pin Control
Reset and Sweep
Use the
Reset Bit
button shown in Figure 13 to set the reset
software command. To set up a DDS sweep, click
FREQUENCY
SWEEP
.
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013
Figure 13. Software Reset and Sweep Select
The sweep function allows users to load a
Start Frequency
,
Stop Frequency
, increment size (
Step Frequency
), number
of
loops
(
N. of Loops
), and
Delay
between each frequency
increment. These commands then load to the device
automatically from the
EVAL-SDP-CB1Z
board.
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014
Figure 14. Sweep Functionality
