Each DAC output in the DAC38RF82 ((or DAC38RF89)) can be supported by a wide band digital up-converter (DUC), which is called a wide-DUC. Figure 33 shows the implementation and signal processing features of the wide-DUC which is only available in the 2-TX modes (Table 9). For complex inputs, the in-phase (or I-channel) is path AB of DAC A and the phase of the NCO in this path (7.5.19) must be set to 0 degrees. Similarly, the quadrature phase (or Q-channel) is path AB of DAC B and the phase of the NCO in this path (7.5.19) must be set to 90 degrees. The NCO frequency in both I and Q paths (7.5.20) must be set to the same value. The SPI interface registers for the wide-DUC are addressed through paging, with page 1 supporting the I-channel and page 2 supporting Q-channel configuration of the wide-DUC. Register PAGE_SET (8.5.8) is used to set the pages. Both pages can be selected at the same time to program both channels of wide-DUC simultaneously.
The output of I and Q channels are added together using the output summation block (Figure 33). Bit 0 and Bit 2 of the register field OUTSUM_SEL must be set to for this to be accomplished.