AD9850 can generate others waveform beside sine wave?
The data sheet shows that the chip includes a comparator, and suggests that it can be used to create a square wave from the (sine wave) DAC output.



It seems like a round-a-bout way to make a digital signal from a digital signal, but the analog filter should keep the jitter down.

The variable duty cycle @captcha refers to on commercial boards is probably created by comparing the filtered sine wave to a variable voltage.