Each delay stage may be configured to phase shift {HEAD ~ a differential signal} based on {TAIL ~ a control signal} 
Each delay stage may be configured to phase shift { HEAD ~ a differential signal } based on { TAIL ~ a control signal }
OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL