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Actually I was referring to the Terasic Board which has an on-board DAC.
I've attached the manual for it (refer to Page 8).
The Analog Devices DAC9797 used in the board can be both AC & DC coupled. But I'm not sure why the Terasic board says no DC signalling.
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You need to look at the schematic, not the user manual. Its likely the schematic has a transformer output.
The DAC output is a current. Its much easier for evaluation board developers to put termination resistors and a transformer on the output, than it is to put a wide bandwidth amplifier that preserves DC. There are not many devices that will do that, eg. a wideband op-amp, most RF amplifiers are AC-coupled devices.
These are high-speed DACs, and are generally not used in applications requiring a DC value.
Cheers,
Dave
Honored Contributor
