Direct Digital Synthesis

The WEADDS0818PI12SFP4CA22G block generates a sine(x) (or any other odd periodic function) analog signal, to be used for calibration purposes. The block consists of the digital Numerically Controlled Oscillator (NCO), followed by a Digital to Analog Converter (DAC). The NCO is clocked at 425 MHz and its output is a 5-bit symbol of the sine(x) waveform.The NCO has a runtime configuration of the desired output waveform, in fact it takes only the first quarter (compressed) Look-Up-Table and generates the whole period by flipping and mirroring it. The frequency is also runtime configurable by a phase increment variable and the gain is mainly configurable by an analog control, although there is the provision of a digital div-by-2 attenuator.