Texas Instruments DAC348 Series, User Manual, Page: 8 / 25

Software Control
www.ti.com
– OSTR: sync from the external LVPECL OSTR signal. Clock divider sync must be enabled with
OSTR set as sync source.
– SYNC: sync from the external LVDS SYNC signal.
– SIF SYNC: sync from SIF Sync. Uncheck and check the SIF Sync button for sync event.
•
NCO: allows fine mixing of the I/Q signal. The procedure to adjust the NCO mixing frequency are listed
below:
1. Enter the DAC sampling frequency in Fsample.
2. Enter the desired mixing frequency in both NCO freq_AB and NCO freq_CD.
3. Press Update freq
4. Sync the NCO block from the following options:
•
REGWR: auto-sync from SIF register write. Writing to either Phase OffsetAB or Phase
OffsetCD can create a sync event.
• OSTR: sync from the external LVPECL OSTR signal. Clock divider sync must be enabled with
OSTR set as sync source. Refer to the datasheet for OSTR period requirement.
• SYNC: sync from the external SYNC signal
• SIF SYNC: sync from SIF Sync. Uncheck and check the SIF Sync button for sync event.
2.2.3 Output Control Options
Figure 5. Output control Options
• Output Options: allows the configuration of reference, output polarity, and output delay
•
Data Routing: provides flexible routing of the A, B, C, and D digital path to the desired output channels.
Note: The DAC3482 does not support this mode.
• DAC Gain: configures the full-scale DAC current and DAC3484/DAC3482 mode. With Rbiaj resistor set
at 1.28k
Ω :
– DAC Gain = 15 for 30mA full-scale current.
– DAC Gain = 10 for 20mA full-scale current (default).
• Output Shutoff On: allows outputs to shut-off when DACCLK GONE, DATACLK GONE, or FIFO
COLLISION alarm event occurs.
8 DAC348x EVM SLAU432 – February 2012
Submit Documentation Feedback
Copyright © 2012, Texas Instruments Incorporated