Building a custom 2 adjustable generators and frequency meter circuit.

AD9850 or AD9851 outputs a sine wave. To convert it to square wave a comparator is used. Am I correct?

It makes no sense because sine wave is modulated out of little rectangles only to be converted back into a rectangle.

Should I look for a different DDS IC? I want to generate narrow impulses, not sine waves, as I realized. Do I need to use a comparator + resistor included in AD985X breakout boards?

Should I use this amplifier?
http://www.k8iqy.com/miscell/aneous/18dblt1253ddsamplifier/lt1253ddsamp.htm

Thanks.