316  
Chapter 7  Tutorial
Square Waveform Generation
7
Spectrum of Above Waveform at 100 kHz
Square Waveform Generation
To eliminate distortion due to aliasing at higher frequencies, the 33210A 
uses a different waveform generation technique to create square waves. 
Square waveforms are created by routing a DDS-generated sine wave 
into a comparator. The digital output from the comparator is then used 
as the basis for the square wave output. 
The duty cycle of the waveform 
can be varied by changing the comparator’s
 threshold. 
Square Waveform Generation Circuitry
Comparator
Threshold
DAC Filter
Voltage DAC
33210A users guide.book  Page 316  Wednesday, July 16, 2008  11:16 AM