Doepfer

This might be REALLY basic, but when using my 145 or 146 lfos' square 
waves to modulate, for example, filter cutoff, I get alot of unpleasant 
clicking when the state changes.  Back when I used to use a Nord there 
was a "module" called smoothing or something like that, which rounded 
the edges of pulse-type control signals.  What's the Doepfer 
equivalent?  Thanks in advance.