Typically, an HCSL output will require termination to provide a current path through the driver. I see an app note that indicates the SI53xx family has this termination built in. For the SI52xx family, though, I can't find any information on internal termination structures. This is implied in an app note that discusses alternate termination to other output types, but I can't find a definitive answer anywhere. In short, does the SI52142 include internal HCSL output termination?