Contents
Intro
Precision 16-Bit, 50Msps DAC, Linear LTC1668 is a good choice for precision AC waveform synthesis, such as DDS and DAS. It’s speed and high resolution allow building calculable AC reference generator, which can be interesting for metrology use after proper calibration.
This differential, current output DAC is sold in small SSOP package. It has a 10mA full-scale output and a 1V output compliance and able to achieve 20ns settling to 0.1% into 50Ω loads. This chip was released in 2001, so it’s proven and mature device.
To speed up the evaluation and allow our readers to have a reference, LT’s own demo board, DC245A-A was used, together with Terasic DE1-SoC FPGA kit.
Paper datasheet is included :). Interface for DAC is parallel, making it easy to use as slave with DE1-SoC GPIO headers.
Output front end using signal transformer, but that will likely be gone, as I need DC accurate outputs too for calibration.
TBD
Modified: Oct. 4, 2016, 4:50 a.m.