AD725- Hsync input

Hi,

I am extracting the Composite sync by using EL1881 and the extracted composite sync is applied to AD725 Hsync input pin.

By using AD725 i am generating composite video output and S-Video output (by separate chips )from individual RGB sources.

In composite video output case, receiving the proper output,

But S-Video output case, there is no proper output its randomly coming and going.

Please suggest the extracted composite sync is applied to AD725 Hsync pin is correct or not.

Thanks,

Siva