I am converting an existing design that uses the AD9957 (Quadrature Digital Upconverter) at 1GSPS to the AD9142 TxDAC at 1.6GSPS.
Is the AD9142 a true Quadrature Digital Upconverter with 2 individual IF outputs (offset by 90degrees from each other) to provide outputs to an external Quadrature Modulator chip? The block diagram on the datasheet (figure 45) implies that it is and that we could use either the I or Q outputs as we currently use the single output on the AD9957. Is this correct?
The FEATURES portion of the datasheet states that the AD9142 "Supports Single DAC mode". What does that imply? Is it simply turning one output off for power control so that it would be a single output like the AD9957?
An earlier discussion this year referred to the "Single DAC mode" and the answers were:
"This function is not currently supported in the AD9142 and will be supported in a separate product to be released later this year"
"The AD9142 product family includes product(s) that send all the input data to a single DAC. The part number for the planned product that does this is the AD9138 and it is expected to be released later this year"
Can you please clarify how the AD9142 operates relative to the AD9957. Can we use only one of the outputs? Does that make sense? Can the other output be powered down". How does the proposed AD9138 differ? When will it be released?
Is there any proposed speed upgrades for the AD9957 (because we use a lot of the other features, programmable RAM, profile selections, etc that are available in that chip.