AD9854 simple dds schematic, does it provide four outputs?

Hello I consider this simple dds http://koti.netplaza.fi/~jonverro/ad9854.htm
I see that he uses a LPF at pin 48. What is it's purpose?

Also what is the comparator out port (36)? Is it an extra port apart from the 49,51,52 and how it is phase related to these ports?

Both questions are about the same feature, generating a low jitter digital clock with a DDS generator. It's described detailed in DDS datsheets and tutorials, I think.